WorldWideScience

Sample records for nc operation mode

  1. Thermal Operating Modes

    International Nuclear Information System (INIS)

    Bechtel SAIC Company

    2002-01-01

    Higher and lower temperature operating modes (e.g., above and below the boiling point of water) are alternative approaches to managing the heat produced by the radioactive decay of spent nuclear fuel. Current analyses indicate that a repository at the Yucca Mountain site is likely to comply with applicable safety standards regardless of the particular thermal operating mode. Both modes have potential advantages and disadvantages. With a higher temperature operating mode (HTOM), waste packages (WPs) can be placed closer together. This reduces the number of drifts, the required emplacement area, construction costs, and occupational risks to construction workers. In addition, the HTOM would minimize the amount of water that might contact the waste for hundreds of years after closure. On the other hand, higher temperatures introduce uncertainties in the understanding of the long-term performance of the repository because of uncertainties in the thermal effects on WP lifetime and the near-field environment around the drifts. A lower temperature operating mode (LTOM) has the potential to reduce uncertainties in long-term performance of the repository by limiting the effects of temperature on WP lifetime and on the near-field environment around the drifts. Depending on the combination of operating parameters, a LTOM could require construction of additional drifts, a larger emplacement area, increased construction costs, increased occupational risks to construction works, and a longer period of ventilation than a HTOM. The repository design for the potential Yucca Mountain site is flexible and can be constructed and operated in various operating modes to achieve specific technical objectives, accommodate future policy decisions, and use of new information. For example, the flexible design can be operated across a range of temperatures and can be tailored to achieve specific thermal requirements in the future. To accommodate future policy decisions, the repository can be

  2. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    2011-01-01

    reveals that companies tend to combine modes of operation; thereby producing unique foreign operation mode “packages” for given activities and/or countries, and that the packages are liable to be modified over time – providing a potentially important optional path for international expansion. Our data...... key markets (China, UK and USA) as the basis for an exploration of the extent to which, and how and why, companies combine clearly different foreign operation modes. We examine their use of foreign operation mode combinations within given value activities as well as within given countries. The study...

  3. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    2011-01-01

    reveals that companies tend to combine modes of operation; thereby producing unique foreign operation mode “packages” for given activities and/or countries, and that the packages are liable to be modified over time—providing a potentially important optional path for international expansion. The data show...... markets (China, UK and USA) is used as the basis for an exploration of the extent to which, and how and why, companies combine clearly different foreign operation modes. We examine their use of foreign operation mode combinations within given value activities as well as within given countries. The study...

  4. Small reactor operating mode

    International Nuclear Information System (INIS)

    Snell, V.G.

    1997-01-01

    There is a potential need for small reactors in the future for applications such as district heating, electricity production at remote sites, and desalination. Nuclear power can provide these at low cost and with insignificant pollution. The economies required by the small scale application, and/or the remote location, require a review of the size and location of the operating staff. Current concepts range all the way from reactors which are fully automatic, and need no local attention for days or weeks, to those with reduced local staff. In general the less dependent a reactor is on local human intervention, the greater its dependence on intrinsic safety features such as passive decay heat removal, low-stored energy and limited reactivity speed and depth in the control systems. A case study of the design and licensing of the SLOWPOKE Energy System heating reactor is presented. (author)

  5. Language Differences and Operation Mode

    DEFF Research Database (Denmark)

    Dasi, Angels; Pedersen, Torben

    2013-01-01

    Language serves different purposes depending on the international activity in question. Language has many dimensions and firms’ communicative requirements vary by operational platform. We argue that different dimensions of language vary in their importance depending on the operation mode chosen...... for a foreign market, so that language distance matters in the case of a home-based sales force, while language incidence is key when operating through a local agent. The hypotheses are tested on a large data set encompassing 462 multinational corporations headquartered in Finland, South Korea, New Zealand......, and Sweden that have undertaken a business operation in a foreign country....

  6. Explicit flow equations and recursion operator of the ncKP hierarchy

    International Nuclear Information System (INIS)

    He, Jingsong; Wang, Lihong; Tu, Junyi; Li, Xiaodong

    2011-01-01

    The explicit expression of the flow equations of the noncommutative Kadomtsev–Petviashvili (ncKP) hierarchy is derived. Compared with the flow equations of the KP hierarchy, our result shows that the additional terms in the flow equations of the ncKP hierarchy indeed consist of commutators of dynamical coordinates {u i }. The recursion operator for the flow equations under n-reduction is presented. Further, under 2-reduction, we calculate a nonlocal recursion operator Φ(2) of the noncommutative Korteweg–de Vries(ncKdV) hierarchy, which generates a hierarchy of local, higher-order flows. Thus we solve the open problem proposed by Olver and Sokolov (1998 Commun. Math. Phys. 193 245–68)

  7. Research of the Power Plant Operational Modes

    Directory of Open Access Journals (Sweden)

    Koismynina Nina M.

    2017-01-01

    Full Text Available In this article the algorithm of the power plant operational modes research is offered. According to this algorithm the program for the modes analysis and connection power transformers choice is developed. The program can be used as educational means for studying of the power plant electric part, at the same time basic data are provided. Also the program can be used for the analysis of the working power plants modes. Checks of the entered data completeness and a choice correctness of the operational modes are provided in the program; in all cases of a deviation from the correct decisions to the user the relevant information is given.

  8. Modeling Operating Modes during Plant Life Cycle

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lind, Morten

    2012-01-01

    Modelling process plants during normal operation requires a set a basic assumptions to define the desired functionalities which lead to fullfillment of the operational goal(-s) for the plant. However during during start-up and shut down as well as during batch operation an ensemble of interrelated...... modes are required to cover the whole operational window of a processs plant including intermediary operating modes. Development of such an model ensemble for a plant would constitute a systematic way of defining the possible plant operating modes and thus provide a platform for also defining a set...... of candidate control structures. The present contribution focuses on development of a model ensemble for a plant with an illustartive example for a bioreactor. Starting from a functional model a process plant may be conceptually designed and qualitative operating models may be developed to cover the different...

  9. 75 FR 69878 - Drawbridge Operation Regulation; Neuse River, New Bern, NC

    Science.gov (United States)

    2010-11-16

    ... Operation Regulation; Neuse River, New Bern, NC AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander, Fifth Coast Guard District, has issued a temporary... is given. NSR has requested a temporary deviation to the existing regulations for the Neuse River...

  10. Two operating modes for turbocharger system

    International Nuclear Information System (INIS)

    Bayomi, Nazih N.; Abd El-Maksoud, Rafea M.

    2012-01-01

    Highlights: ► A turbocharger system that operates in power assisted mode is introduced. ► The parameters affecting performance of the turbocharger is presented. ► Different operational charts for turbocharger are presented. ► The parametric study is helpful guide to determine turbocharger dimensioning. - Abstract: The present paper introduces a turbocharger system that operates in two different modes according to turbocharging requirements. In the first mode, the turbocharger is operating with power assistance at lower engine speeds where the power of the exhaust gases is insufficient. Thereafter, the second mode is switched leading the compressor and the turbine of the turbocharger to rotate separately for best performance. Analysis is presented to find out the parameters affecting the operation of the turbocharger and their values to achieve enhanced turbocharger performance with high efficient impellers. The parameters studied are based on data of the turbocharger operating conditions and the operational requirements of the engine. The analysis considers the turbocharger system, its turbine and its compressor. The operational charts demonstrate the simulated results for two operating modes. This study is helpful as a guide to determine the turbocharger dimensioning and blade profile assignment without using any given blade dimensional value.

  11. 77 FR 45247 - Drawbridge Operation Regulations; Gallants Channel, Beaufort, NC

    Science.gov (United States)

    2012-07-31

    ... to accommodate the Neuse River Keeper Foundation Sprint Triathlon. DATES: This deviation is effective... operating regulations to accommodate the Neuse River Keeper Foundation Sprint Triathlon. Under the current... designated time period. This deviation from the operating regulations is authorized under 33 CFR 117.35...

  12. Optimal mode of operation for biomass production

    NARCIS (Netherlands)

    Betlem, Ben H.L.; Roffel, Brian; Mulder, P.

    2002-01-01

    The rate of biomass production is optimised for a predefined feed exhaustion using the residue ratio as a degree of freedom. Three modes of operation are considered: continuous, repeated batch, and repeated fed-batch operation. By means of the Production Curve, the transition points of the optimal

  13. Piezoelectric energy harvesting through shear mode operation

    International Nuclear Information System (INIS)

    Malakooti, Mohammad H; Sodano, Henry A

    2015-01-01

    Piezoelectric materials are excellent candidates for use in energy harvesting applications due to their high electromechanical coupling properties that enable them to convert input mechanical energy into useful electric power. The electromechanical coupling coefficient of the piezoelectric material is one of the most significant parameters affecting energy conversion and is dependent on the piezoelectric mode of operation. In most piezoceramics, the d 15 piezoelectric shear coefficient is the highest coefficient compared to the commonly used axial and transverse modes that utilize the d 33 and the d 31 piezoelectric strain coefficients. However, complicated electroding methods and challenges in evaluating the performance of energy harvesting devices operating in the shear mode have slowed research in this area. The shear deformation of a piezoelectric layer can be induced in a vibrating sandwich beam with a piezoelectric core. Here, a model based on Timoshenko beam theory is developed to predict the electric power output from a cantilever piezoelectric sandwich beam under base excitations. It is shown that the energy harvester operating in the shear mode is able to generate ∼50% more power compared to the transverse mode for a numerical case study. Reduced models of both shear and transverse energy harvesters are obtained to determine the optimal load resistance in the system and perform an efficiency comparison between two models with fixed and adaptive resistances. (paper)

  14. C5 capsule operation modes analysis

    International Nuclear Information System (INIS)

    Negut, Gh.; Ancuta, Mirela; Stefan, Violeta

    2008-01-01

    This paper is part of the Nuclear Research Institute Program 13 dedicated to 'TRIGA Research Reactor performance enhancing' and its objective is improving the engineering of the structural materials irradiation. The paper raises the knowledge level on C5 capsule irradiation modes and utilizes previous results in order to increase C5 performances. In the paper the irradiation modes to test zirconium yttrium sample are assessed. These tests are proposed by AECL. There are presented the C5 initial conditions and models. Also. there are presented the thermal hydraulic conditions during normal and accidental operation. The results will be used in the C5 safety report. (authors)

  15. CMOS Current-mode Operational Amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1992-01-01

    current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain bandwidth product of 8 MHz, an offset current of 0.8 ¿A (signal-range ±700¿A) and a (theoretically) unlimited slew-rate. The amplifier is realized in a standard CMOS 2......A fully differential-input differential-output current-mode operational amplifier (COA) is described. The amplifier utilizes three second generation current-conveyors (CCII) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...

  16. A CMOS current-mode operational amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1993-01-01

    current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain-bandwidth product of 3 MHz, an offset current of 0.8 μA (signal range ±700 μA), and a (theoretically) unlimited slew rate. The amplifier is realized in a standard CMOS 2......A fully differential-input, differential-output, current-mode operational amplifier (COA) is described. The amplifier utilizes three second-generation current conveyors (CCIIs) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced...

  17. CMOS Current-mode Operational Amplifier

    OpenAIRE

    Kaulberg, Thomas

    1992-01-01

    A fully differential-input differential-output current-mode operational amplifier (COA) is described. The amplifier utilizes three second generation current-conveyors (CCII) as the basic building blocks. It can be configured to provide either a constant gain-bandwidth product in a fully balanced current-mode feedback amplifier or a constant bandwidth in a transimpedance feedback amplifier. The amplifier is found to have a gain bandwidth product of 8 MHz, an offset current of 0.8 ¿A (signal-r...

  18. Analysis of the ITER cryoplant operational modes

    International Nuclear Information System (INIS)

    Henry, D.; Journeaux, J.Y.; Roussel, P.; Michel, F.; Poncet, J.M.; Girard, A.; Kalinin, V.; Chesny, P.

    2007-01-01

    In the framework of an EFDA task, CEA is carrying out an analysis of the various ITER cryoplant operational modes. According to the project integration document, ITER is designed to be operated 365 days per year in order to optimize the available time of the Tokamak. It is anticipated that operation will be performed in long periods separated by maintenance periods (e.g. 10 days continuous operation and 1 week break) with annual or bi-annual major shutdown periods of a few months for maintenance, further installation and commissioning. For this operation schedule, auxiliary subsystems like the cryoplant and the cryodistribution have to cope with different heat loads which depend on the different ITER operating states. The cryoplant consists of four identical 4.5 K refrigerators and two 80 K helium loops coupled with two LN2 modules. All of these cryogenic subsystems have to operate in parallel to remove the heat loads from the magnet, 80 K shields, cryopumps and other small users. After a brief recall of the main particularities of a cryogenic system operating in a Tokamak environment, the first part of this study is dedicated to the assessment of the main ITER operation states. A new design of refrigeration loop for the HTS current leads, the updated layout of the cryodistribution system and revised strategy for operations of the cryopumps have been taken into consideration. The relevant normal operating scenarios of the cryoplant are checked for the typical ITER operating states like plasma operation state, short term stand by, short term maintenance, or test and conditioning state. The second part of the paper is dedicated to the abnormal operating modes coming from the magnets and from those generated by the cryoplant itself. The occurrence of a fast discharge or a quench of the magnets generates large heat loads disturbances and produces exceptional high mass flow rates which have to be managed by the cryoplant, while a failure of a cryogenic component induces

  19. Gamma irradiation facility: Evaluation of operational modes

    International Nuclear Information System (INIS)

    Adesanmi, C.A.; Ali, M.S.; Shonowo, O.A.; Akueche, E.C.; Sadare, O.O.; Mustapha, T.K.; Yusuf, U.; Inyanda, A.K.

    2007-01-01

    The multipurpose Gamma Irradiation Facility (GIF) at the Nuclear Technology Centre (NTC), Sheda Science and Technology Complex (SHETSCO), Abuja, Nigeria is designed as a semi-commercial plant with facilities for research and development (R and D). The design takes into account the different needs of the various research applications which require a wide dose range, a variety of techniques, different product sizes, shapes, mass, volume, densities and types. Programmable doses are used for food irradiation (0.04 - 10 kGy), biological seed mutation breeding and sterile insect technique (STI) (0.01- 5 kGy) sterilization of medical, pharmaceutical and cosmetic products and packages (up to 25 kGy) and cross-linking of polymers (up to 100 kGy). The six different modes of operations (sample elevator, stationary, swiveling, 2-path inner lane and 2-path outer lane and 4-path line) were evaluated. The dose range, mass range and range of irradiation time practicable were established and advantages for radiation processing of food and industrial products were enumerated for the six modes of operations for the first time

  20. Representing Operational Modes for Situation Awareness

    Science.gov (United States)

    Kirchhübel, Denis; Lind, Morten; Ravn, Ole

    2017-01-01

    Operating complex plants is an increasingly demanding task for human operators. Diagnosis of and reaction to on-line events requires the interpretation of real time data. Vast amounts of sensor data as well as operational knowledge about the state and design of the plant are necessary to deduct reasonable reactions to abnormal situations. Intelligent computational support tools can make the operator’s task easier, but they require knowledge about the overall system in form of some model. While tools used for fault-tolerant control design based on physical principles and relations are valuable tools for designing robust systems, the models become too complex when considering the interactions on a plant-wide level. The alarm systems meant to support human operators in the diagnosis of the plant-wide situation on the other hand fail regularly in situations where these interactions of systems lead to many related alarms overloading the operator with alarm floods. Functional modelling can provide a middle way to reduce the complexity of plant-wide models by abstracting from physical details to more general functions and behaviours. Based on functional models the propagation of failures through the interconnected systems can be inferred and alarm floods can potentially be reduced to their root-cause. However, the desired behaviour of a complex system changes due to operating procedures that require more than one physical and functional configuration. In this paper a consistent representation of possible configurations is deduced from the analysis of an exemplary start-up procedure by functional models. The proposed interpretation of the modelling concepts simplifies the functional modelling of distinct modes. The analysis further reveals relevant links between the quantitative sensor data and the qualitative perspective of the diagnostics tool based on functional models. This will form the basis for the ongoing development of a novel real-time diagnostics system based

  1. Representing Operational Modes for Situation Awareness

    International Nuclear Information System (INIS)

    Kirchhübel, Denis; Lind, Morten; Ravn, Ole

    2017-01-01

    Operating complex plants is an increasingly demanding task for human operators. Diagnosis of and reaction to on-line events requires the interpretation of real time data. Vast amounts of sensor data as well as operational knowledge about the state and design of the plant are necessary to deduct reasonable reactions to abnormal situations. Intelligent computational support tools can make the operator’s task easier, but they require knowledge about the overall system in form of some model. While tools used for fault-tolerant control design based on physical principles and relations are valuable tools for designing robust systems, the models become too complex when considering the interactions on a plant-wide level. The alarm systems meant to support human operators in the diagnosis of the plant-wide situation on the other hand fail regularly in situations where these interactions of systems lead to many related alarms overloading the operator with alarm floods. Functional modelling can provide a middle way to reduce the complexity of plant-wide models by abstracting from physical details to more general functions and behaviours. Based on functional models the propagation of failures through the interconnected systems can be inferred and alarm floods can potentially be reduced to their root-cause. However, the desired behaviour of a complex system changes due to operating procedures that require more than one physical and functional configuration. In this paper a consistent representation of possible configurations is deduced from the analysis of an exemplary start-up procedure by functional models. The proposed interpretation of the modelling concepts simplifies the functional modelling of distinct modes. The analysis further reveals relevant links between the quantitative sensor data and the qualitative perspective of the diagnostics tool based on functional models. This will form the basis for the ongoing development of a novel real-time diagnostics system based

  2. An integrated operation mode for green logistics of enterprises

    Institute of Scientific and Technical Information of China (English)

    Yu Chengxue; Wu Chunyou; Fan Yu

    2006-01-01

    The integrated operation mode of green logistics is a new enterprise's logistics operation and management mode concerning environment issues based on the traditional integrated mode. Through comparative study on the integrated operation mode of logistics based on self-operation, the operation mode of an integrated logistics of enterprises based on TPL, the green-supply chain management, and the operation mode of eco-industrial park (EIP), a relatively complete objective system structure is put forward for the integrated operation mode of green logistics of enterprises. Furthermore, the correspondent practical mode is also set up to help enterprises, especially for the manufacturing companies, not only improve the environment effectively, but support the technological framework for the enterprise's economic performance and social benefits in order to realize economic, social and environmental benefits are concerned.

  3. Modeling Operating Modes for the Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, H.; Jørgensen, Sten Bay

    2012-01-01

    of the process plant, its function and its structural elements. The paper explains how the means-end concepts of MFM can be used to provide formalized definitions of plant operation modes. The paper will introduce the mode types defined by MFM and show how selected operation modes can be represented...

  4. 33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Albemarle Sound, Pamlico Sound... AND RESTRICTED AREA REGULATIONS § 334.410 Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations. (a) Target areas—(1) North Landing River (Currituck Sound...

  5. Self-seeded operation of the LCLS hard X-ray FEL in the long-bunch mode

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    Self-seeding options for the LCLS baseline were recently investigated using a scheme which relies on a single-crystal monochromator in Bragg-transmission geometry. The LCLS low-charge (0.02 nC) mode of operation was considered in order to demonstrate the feasibility of the proposed scheme. The wakefield effects from the linac and from the undulator vacuum chamber are much reduced at such low charge, and can be ignored. In this paper we extend our previous investigations to the case of the LCLS mode of operation with nominal charge. Based on the LCLS start-to-end simulation for an electron beam charge of 0.25 nC, and accounting for the wakefields from the undulator vacuum chamber we demonstrate that the same simplest self-seeding system (two undulators with a single-crystal monochromator in between) is appropriate not only for short (few femtosecond) bunches, but for longer bunches too. (orig.)

  6. Self-seeded operation of the LCLS hard X-ray FEL in the long-bunch mode

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2010-12-01

    Self-seeding options for the LCLS baseline were recently investigated using a scheme which relies on a single-crystal monochromator in Bragg-transmission geometry. The LCLS low-charge (0.02 nC) mode of operation was considered in order to demonstrate the feasibility of the proposed scheme. The wakefield effects from the linac and from the undulator vacuum chamber are much reduced at such low charge, and can be ignored. In this paper we extend our previous investigations to the case of the LCLS mode of operation with nominal charge. Based on the LCLS start-to-end simulation for an electron beam charge of 0.25 nC, and accounting for the wakefields from the undulator vacuum chamber we demonstrate that the same simplest self-seeding system (two undulators with a single-crystal monochromator in between) is appropriate not only for short (few femtosecond) bunches, but for longer bunches too. (orig.)

  7. Operating modes of superconducting tunnel junction device

    Energy Technology Data Exchange (ETDEWEB)

    Maehata, Keisuke [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1998-07-01

    In the Electrotechnical Laboratory, an Nb type superconducting tunnel junction (STJ) device with 200 x 200 sq. micron in area and super high quality was manufactured. By using 55-fe source, response of this large area STJ to X-ray was measured. In this measurement, two action modes with different output wave height from front amplifier were observed. Then, in this study, current-voltage feature of the element in each action mode was analyzed to elucidate a mechanism to form such two action modes. The feature was analyzed by using first order approximate solution on cavity resonance mode of Sine-Gordon equation. From the analytical results, it could be supposed that direction and magnitude of effective magnetic field penetrating into jointed area changed by an induction current effect owing to impressing speed of the magnetic field, which brings two different current-voltage features to make possible to observe two action modes with different pulse wave height. (G.K.)

  8. Dual-Mode Scramjet Flameholding Operability Measurements

    Science.gov (United States)

    Donohue, James M.

    2012-01-01

    Flameholding measurements were made in two different direct connect combustor facilities that were designed to simulate a cavity flameholder in the flowfield of a hydrocarbon fueled dual-mode scramjet combustor. The presence of a shocktrain upstream of the flameholder has a significant impact on the inlet flow to the combustor and on the flameholding limits. A throttle was installed in the downstream end of the test rigs to provide the needed back-pressurization and decouple the operation of the flameholder from the backpressure formed by heat release and thermal choking, as in a flight engine. Measurements were made primarily with ethylene fuel but a limited number of tests were also performed with heated gaseous JP-7 fuel injection. The flameholding limits were measured by ramping inlet air temperature down until blowout was observed. The tests performed in the United Technologies Research Center (UTRC) facility used a hydrogen fueled vitiated air heater, Mach 2.2 and 3.3 inlet nozzles, a scramjet combustor rig with a 1.666 by 6 inch inlet and a 0.65 inch deep cavity. Mean blowout temperature measured at the baseline condition with ethylene fuel, the Mach 2.2 inlet and a cavity pressure of 21 psia was 1502 oR. Flameholding sensitivity to a variety of parameters was assessed. Blowout temperature was found to be most sensitive to fuel injection location and fuel flowrates and surprisingly insensitive to operating pressure (by varying both back-pressurization and inlet flowrate) and inlet Mach number. Video imaging through both the bottom and side wall windows was collected simultaneously and showed that the flame structure was quite unsteady with significant lateral movements as well as movement upstream of the flameholder. Experiments in the University of Virginia (UVa) test facility used a Mach 2 inlet nozzle with a 1 inch by 1.5 inch exit cross section, an aspect ratio of 1.5 versus 3.6 in the UTRC facility. The UVa facility tests were designed to measure the

  9. Mode coupling in hybrid square-rectangular lasers for single mode operation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiu-Wen; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn; Yang, Yue-De; Xiao, Jin-Long; Weng, Hai-Zhong; Xiao, Zhi-Xiong [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100083 (China)

    2016-08-15

    Mode coupling between a square microcavity and a Fabry-Pérot (FP) cavity is proposed and demonstrated for realizing single mode lasers. The modulations of the mode Q factor as simulation results are observed and single mode operation is obtained with a side mode suppression ratio of 46 dB and a single mode fiber coupling loss of 3.2 dB for an AlGaInAs/InP hybrid laser as a 300-μm-length and 1.5-μm-wide FP cavity connected to a vertex of a 10-μm-side square microcavity. Furthermore, tunable single mode operation is demonstrated with a continuous wavelength tuning range over 10 nm. The simple hybrid structure may shed light on practical applications of whispering-gallery mode microcavities in large-scale photonic integrated circuits and optical communication and interconnection.

  10. Dynamics of Foreign Operations Modes and Their Combinations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    Companies’ choice of foreign operation modes (FOM) has been a core subject of international business studies basically from its beginning (Hymer, 1960 [1976]; Root, 1964). A halfcentury of research has brought us a set of established perspectives on companies’ foreign operation mode choices...

  11. Charging system with galvanic isolation and multiple operating modes

    Science.gov (United States)

    Kajouke, Lateef A.; Perisic, Milun; Ransom, Ray M.

    2013-01-08

    Systems and methods are provided for operating a charging system with galvanic isolation adapted for multiple operating modes. A vehicle charging system comprises a DC interface, an AC interface, a first conversion module coupled to the DC interface, and a second conversion module coupled to the AC interface. An isolation module is coupled between the first conversion module and the second conversion module. The isolation module comprises a transformer and a switching element coupled between the transformer and the second conversion module. The transformer and the switching element are cooperatively configured for a plurality of operating modes, wherein each operating mode of the plurality of operating modes corresponds to a respective turns ratio of the transformer.

  12. Representing Operational Modes for Situation Awareness

    DEFF Research Database (Denmark)

    Kirchhübel, Denis; Lind, Morten; Ravn, Ole

    2017-01-01

    reasonable reactions to abnormal situations. Intelligent computational support tools can make the operator's task easier, but they require knowledge about the overall system in form of some model. While tools used for fault-tolerant control design based on physical principles and relations are valuable tools...... for designing robust systems, the models become too complex when considering the interactions on a plant-wide level. The alarm systems meant to support human operators in the diagnosis of the plant-wide situation on the other hand fail regularly in situations where these interactions of systems lead to many...... the interconnected systems can be inferred and alarm floods can potentially be reduced to their root-cause. However, the desired behaviour of a complex system changes due to operating procedures that require more than one physical and functional configuration. In this paper a consistent representation of possible...

  13. 77 FR 25652 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway (AIWW), at Wrightsville Beach, NC...

    Science.gov (United States)

    2012-05-01

    ... are expected to have minimal impacts on mariners due to the short duration that the moveable bridges... North Carolina Department of Transportation (NCDOT) bridges: The S.R. 74 Bridge, across the AIWW, mile 283.1 at Wrightsville Beach, NC; the Cape Fear Memorial Bridge across the Cape Fear River, mile 26.8...

  14. 77 FR 50376 - Drawbridge Operation Regulation, Atlantic Intracoastal Waterway (AIWW); Wrightsville Beach, NC...

    Science.gov (United States)

    2012-08-21

    ... duration that the moveable bridges will be maintained in the closed position. The races have been reserved... of Transportation (NCDOT) bridges: The S.R. 74 Bridge, across the AIWW, mile 283.1 at Wrightsville Beach, NC; the Cape Fear Memorial Bridge across the Cape Fear River, mile 26.8; and the Isabel S. Holmes...

  15. Mode of operation of a nuclear reactor

    International Nuclear Information System (INIS)

    Morita, T.

    1976-01-01

    A method is proposed for the operation of a nuclear reactor guaranteeing an essentially symmetrical axial power distribution during normal operation by controlling the changes occuring in the reactor power partly by variation of the concentration of the neutron-absorbing element and partly by variation of the control rod positions. The representative parameters are recorded for the upper and lower half and adjusted to a predetermined reference value. In using this method, the axial power peals are reduced and power losses avoided. (RW) [de

  16. Simulation and Analysis of the Hybrid Operating Mode in ITER

    International Nuclear Information System (INIS)

    Kessel, C.E.; Budny, R.V.; Indireshkumar, K.

    2005-01-01

    The hybrid operating mode in ITER is examined with 0D systems analysis, 1.5D discharge scenario simulations using TSC and TRANSP, and the ideal MHD stability is discussed. The hybrid mode has the potential to provide very long pulses and significant neutron fluence if the physics regime can be produced in ITER. This paper reports progress in establishing the physics basis and engineering limitation for the hybrid mode in ITER

  17. Modeling Operating Modes for the Monju Nuclear Power Plant

    DEFF Research Database (Denmark)

    Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay

    2012-01-01

    The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...... for the Japanese fast breeder reactor plant MONJU....

  18. Modifications needed to operate PWR's plants in G-Mode

    International Nuclear Information System (INIS)

    Stainman, J.P.

    1985-01-01

    The production of electricity from PWR nuclear plants represents 44% of the total production of electricity in France for 1984, and 68% of the electricity produced by Thermal power plants (127 TWh over 187 TWh). These data show clearly that the French PWR plants do not work in ''base mode'' anymore but have to fit production with consumption, in other words to assume the frequency control. To participate permanently to the load follow and frequency control, it appeared that some improvements in the field of pressurizer level and pressure control were necessary as well as in the field of operator aids computer. It should be noted that these improvements are useful even without taking into account the constraints due to load follow and frequency control because of the mechanical stress in the CVCS piping, for instance. Some additional tests are planned to better identify this specific problem. The need of a more flexible operating mode than ones given by the initial system (black control rods), significantly reduced in 1973 due to the application of the ECCS criterion, led EDF and Framatome to develop a new operating mode (G. Mode) allowing a faster power escalation (5% PN/mn) whatever the fuel burn-up. This new operating mode improves significantly also the flexibility of operation when the frequency control is needed, and helps a lot the operators in such cases. All the 900 MWe Nuclear plants will be able to operate in ''G mode'' before the end of 1984

  19. Identifying a "default" visual search mode with operant conditioning.

    Science.gov (United States)

    Kawahara, Jun-ichiro

    2010-09-01

    The presence of a singleton in a task-irrelevant domain can impair visual search. This impairment, known as the attentional capture depends on the set of participants. When narrowly searching for a specific feature (the feature search mode), only matching stimuli capture attention. When searching broadly (the singleton detection mode), any oddball captures attention. The present study examined which strategy represents the "default" mode using an operant conditioning approach in which participants were trained, in the absence of explicit instructions, to search for a target in an ambiguous context in which one of two modes was available. The results revealed that participants behaviorally adopted the singleton detection as the default mode but reported using the feature search mode. Conscious strategies did not eliminate capture. These results challenge the view that a conscious set always modulates capture, suggesting that the visual system tends to rely on stimulus salience to deploy attention.

  20. The H-mode operational window as determined from the ITER H-mode database

    International Nuclear Information System (INIS)

    Ryter, F.; Kardaun, O.J.W.F.; Stroth, U.

    1994-01-01

    The H-mode is a promising regime for fusion reactors and it is essential to be able to predict its operational window in future devices. The 'H-Mode Database Working Group' started in 1992 to gather, analyze and compare H-mode threshold data from several divertor tokamaks so that predictions could be made. The database and first results were presented and the threshold database has been improved and extended since. The work has two objectives: 1) to predict the minimum heating power necessary to reach the H-mode in future devices, 2) to contribute to physics studies of the L-H transition. (author) 11 refs., 2 figs

  1. Perspective gyrotron with mode converter for co- and counter-rotation operating modes

    International Nuclear Information System (INIS)

    Chirkov, A. V.; Kuftin, A. N.; Denisov, G. G.

    2015-01-01

    A gyrotron oscillator operating efficiently at modes of both rotations was developed and tested. The gyrotron operation can be switched between two modes: co- and counter rotating ones with respect to electron rotation in a resonance magnetic field. A synthesized mode converter provides output of both waves in the form of two different paraxial wave beams corresponding to direction of the mode rotation. Measured gyrotron power (up to 2 MW), interaction efficiency (34%), and diffraction losses in the mode converter (≈2%) agree well with the design values. The proposed gyrotron scheme alloys principal enhancement in the device parameters—possibility of electronic switching of output wave beam direction and possibility to arrange an effective scheme to provide frequency/phase locking of a gyrotron-oscillator

  2. Perspective gyrotron with mode converter for co- and counter-rotation operating modes

    Energy Technology Data Exchange (ETDEWEB)

    Chirkov, A. V.; Kuftin, A. N. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ul' yanov Street, 603950 Nizhny Novgorod (Russian Federation); Denisov, G. G. [Institute of Applied Physics, Russian Academy of Sciences, 46 Ul' yanov Street, 603950 Nizhny Novgorod (Russian Federation); University of Nizhny Novgorod, 23 Prospekt Gagarina, 603950 Nizhny Novgorod (Russian Federation)

    2015-06-29

    A gyrotron oscillator operating efficiently at modes of both rotations was developed and tested. The gyrotron operation can be switched between two modes: co- and counter rotating ones with respect to electron rotation in a resonance magnetic field. A synthesized mode converter provides output of both waves in the form of two different paraxial wave beams corresponding to direction of the mode rotation. Measured gyrotron power (up to 2 MW), interaction efficiency (34%), and diffraction losses in the mode converter (≈2%) agree well with the design values. The proposed gyrotron scheme alloys principal enhancement in the device parameters—possibility of electronic switching of output wave beam direction and possibility to arrange an effective scheme to provide frequency/phase locking of a gyrotron-oscillator.

  3. Energy and Exergy Performance of three FPSO Operational Modes

    DEFF Research Database (Denmark)

    Sánchez, Yamid Alberto Carranza; Junior, Silvio de Oliveira; da Silva, Julio Augusto Mendes

    2015-01-01

    by the FPSO operator. Energy and exergy criteria have been applied to evaluate and compare the performance of components and systems of the three operational modes of the FPSO. The processing and utilities plants have been modeled and simulated by using Aspen HYSYS®. Results indicate that higher oil content...

  4. Cyclotron operating mode determination based on intelligent methods

    International Nuclear Information System (INIS)

    Ouda, M.M.E.M.

    2011-01-01

    Particle accelerators are generators that produce beams of charged particles with energies depending on the accelerator type. The MGC-20 cyclotron is a cyclic particle accelerator used for accelerating protons, deuterons, alpha particles, and helium-3 to different energies. Main applications are isotopes production, nuclear reactions studies, and mass spectroscopy studies and other industrial applications. The cyclotron is a complicated machine depends on using a strong magnetic field and high frequency-high voltage electric field together to accelerate and bend charged particles inside the accelerating chamber. It consists of the following main parts, the radio frequency system, the main magnet with the auxiliary concentric and harmonic coils, the electrostatic deflector, and the ion source, the beam transport system, and high precision and high stability DC power supplies.To accelerate a particle to certain energy, one has to adjust the cyclotron operating parameters to be suitable to accelerate this particle to that energy. If the cyclotron operating parameters together are adjusted to accelerate a charged particle to certain energy, then these parameters together are named the operating mode to accelerate this particle to that energy. For example the operating mode to accelerate protons to 18 MeV is named the (18 MeV protons operating mode). The operating mode includes many parameters that must be adjusted together to be successful to accelerate, extract, focus, steer a particle from the ion source to the experiment. Due to the big number of parameters in the operating modes, 19 parameters have been selected in this thesis to be used in an intelligent system based on feed forward back propagation neural network to determine the parameters for new operating modes. The new intelligent system depends on the available information about the currently used operating modes.The classic way to determine a new operating mode was depending on trial and error method to

  5. Laser modes as an eigenfunction of an operator equation

    International Nuclear Information System (INIS)

    Ripper, J.E.; Campos, M.D.; Pudensi, M.A.A.

    A new method is proposed of arriving to an approximate solution into mode problems which cannot be treated by the traditional methods. Basically the idea is to treat the laser mode as an eigenfunction of an operator equation so that the mathematical methods developed to treat the wave equations in quantum mechanics can be used as tools to solve the equation. (L.C.) [pt

  6. Recent progress towards advanced mode of operation on JET

    International Nuclear Information System (INIS)

    Litaudon, X.; Crisanti, F.; Frigione, D.

    2003-01-01

    This series of slides presents the recent performance of JET concerning ITB (internal transport barrier) operating mode. Pellet refuelling without ITB destruction has been achieved at n eo /n GW ∼ 1. A wide reversed shear ITB (3.6 m) has been sustained with mild ELM (edge localized modes) and no apparent impurity accumulation. ITBs have been maintained thanks to a simultaneous optimisation of the q-profile and edge condition, which opens the way for a steady-state ITB

  7. A Current-Mode Common-Mode Feedback Circuit (CMFB) with Rail-to-Rail Operation

    Science.gov (United States)

    Suadet, Apirak; Kasemsuwan, Varakorn

    2011-03-01

    This paper presents a current-mode common-mode feedback (CMFB) circuit with rail-to-rail operation. The CMFB is a stand-alone circuit, which can be connected to any low voltage transconductor without changing or upsetting the existing circuit. The proposed CMFB employs current mirrors, operating as common-mode detector and current amplifier to enhance the loop gain of the CMFB. The circuit employs positive feedback to enhance the output impedance and gain. The circuit has been designed using a 0.18 μm CMOS technology under 1V supply and analyzed using HSPICE with BSIM3V3 device models. A pseudo-differential amplifier using two common sources and the proposed CMFB shows rail to rail output swing (± 0.7 V) with low common-mode gain (-36 dB) and power dissipation of 390 μW.

  8. Intensity modulated operating mode of the rotating gamma system.

    Science.gov (United States)

    Sengupta, Bishwambhar; Gulyas, Laszlo; Medlin, Donald; Koroknai, Tibor; Takacs, David; Filep, Gyorgy; Panko, Peter; Godo, Bence; Hollo, Tamas; Zheng, Xiao Ran; Fedorcsak, Imre; Dobai, Jozsef; Bognar, Laszlo; Takacs, Endre

    2018-05-01

    The purpose of this work was to explore two novel operation modalities of the rotating gamma systems (RGS) that could expand its clinical application to lesions in close proximity to critical organs at risk (OAR). The approach taken in this study consists of two components. First, a Geant4-based Monte Carlo (MC) simulation toolkit is used to model the dosimetric properties of the RGS Vertex 360™ for the normal, intensity modulated radiosurgery (IMRS), and speed modulated radiosurgery (SMRS) operation modalities. Second, the RGS Vertex 360™ at the Rotating Gamma Institute in Debrecen, Hungary is used to collect experimental data for the normal and IMRS operation modes. An ion chamber is used to record measurements of the absolute dose. The dose profiles are measured using Gafchromic EBT3 films positioned within a spherical water equivalent phantom. A strong dosimetric agreement between the measured and simulated dose profiles and penumbra was found for both the normal and IMRS operation modes for all collimator sizes (4, 8, 14, and 18 mm diameter). The simulated falloff and maximum dose regions agree better with the experimental results for the 4 and 8 mm diameter collimators. Although the falloff regions align well in the 14 and 18 mm collimators, the maximum dose regions have a larger difference. For the IMRS operation mode, the simulated and experimental dose distributions are ellipsoidal, where the short axis aligns with the blocked angles. Similarly, the simulated dose distributions for the SMRS operation mode also adopt an ellipsoidal shape, where the short axis aligns with the angles where the orbital speed is highest. For both modalities, the dose distribution is highly constrained with a sharper penumbra along the short axes. Dose modulation of the RGS can be achieved with the IMRS and SMRS modes. By providing a highly constrained dose distribution with a sharp penumbra, both modes could be clinically applicable for the treatment of lesions in close

  9. Mixed-mode Operating System for Real-time Performance

    OpenAIRE

    M.M. Hasan; S. Sultana; C.K. Foo

    2017-01-01

    The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface (GUI) operating system which is typically nonreal-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time...

  10. Mixed - mode Operating System for Real - time Performance

    OpenAIRE

    Hasan M. M.; Sultana S.; Foo C.K.

    2017-01-01

    The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface(GUI)operating system which is typicallynon-real-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time e...

  11. Distributed Generation using Indirect Matrix Converter in Boost Operating Mode

    DEFF Research Database (Denmark)

    Liu, Xiong; Loh, Poh Chiang; Wang, Peng

    2011-01-01

    , reverse power flow operation of IMC can be implemented to meet voltage boost requirement, where the input ac source is connected to the converter's voltage source side and the output utility grid or load is connected to the current source side. This paper proposes control schemes of IMC under reverse...... power flow operation for both grid-connected and isolated modes with distributed generation suggested as a potential application. In grid-connected mode, the commanded power must be extracted from the input ac source to the grid, in addition to guarantee sinusoidal input/output waveforms, unity input...

  12. Characterization of pseudosingle bunch kick-and-cancel operational mode

    Directory of Open Access Journals (Sweden)

    C. Sun

    2015-12-01

    Full Text Available Pseudosingle-bunch kick-and-cancel (PSB-KAC is a new operational mode at the Advanced Light Source of Lawrence Berkeley National Laboratory that provides full timing and repetition rate control for single x-ray pulse users while being fully transparent to other users of synchrotron radiation light. In this operational mode, a single electron bunch is periodically displaced from a main bunch train by a fast kicker magnet with a user-on-demand repetition rate, creating a single x-ray pulse to be matched to a typical laser excitation pulse rate. This operational mode can significantly improve the signal to noise ratio of single x-ray pulse experiments and drastically reduce dose-induced sample damage rate. It greatly expands the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In this paper, we carry out extensive characterizations of this PSB-KAC mode both numerically and experimentally. This includes the working principle of this mode, resonance conditions and beam stability, experimental setups, and diagnostic tools and measurements.

  13. Characterization of pseudosingle bunch kick-and-cancel operational mode

    Science.gov (United States)

    Sun, C.; Robin, D. S.; Steier, C.; Portmann, G.

    2015-12-01

    Pseudosingle-bunch kick-and-cancel (PSB-KAC) is a new operational mode at the Advanced Light Source of Lawrence Berkeley National Laboratory that provides full timing and repetition rate control for single x-ray pulse users while being fully transparent to other users of synchrotron radiation light. In this operational mode, a single electron bunch is periodically displaced from a main bunch train by a fast kicker magnet with a user-on-demand repetition rate, creating a single x-ray pulse to be matched to a typical laser excitation pulse rate. This operational mode can significantly improve the signal to noise ratio of single x-ray pulse experiments and drastically reduce dose-induced sample damage rate. It greatly expands the capabilities of synchrotron light sources to carry out dynamics and time-of-flight experiments. In this paper, we carry out extensive characterizations of this PSB-KAC mode both numerically and experimentally. This includes the working principle of this mode, resonance conditions and beam stability, experimental setups, and diagnostic tools and measurements.

  14. Startup methods for single-mode gyrotron operation

    International Nuclear Information System (INIS)

    Whaley, D.R.; Tran, M.Q.; Alberti, S.; Tran, T.M.; Antonsen, T.M. Jr.; Dubrovin, A.; Tran, C.

    1995-01-01

    Experimental results of startup studies on a 118 GHz TE 22,6 gyrotron are presented and compared with theory. The startup paths through the energy-velocity-pitch-angle plane are determined by the time evolution of the beam parameters during the startup phase. These startup paths are modified by changing the anode and cathode voltage rise from zero to their nominal values and are seen to determine the cavity oscillating mode. Experimental results show specifically that competition between the TE 22,6 and TE -19,7 mode can be completely eliminated by use of the proper startup method in a case where a typical triode startup results in oscillation in the competing TE -19,7 mode. These new results are shown to be in excellent agreement with the theory whose approach is general and therefore applicable to gyrotrons operating in any arbitrary cavity mode. (author) 3 figs., 4 refs

  15. OPERATION MODES AND CHARACTERISTICS OF PLASMA DIPOLE ANTENNA

    Directory of Open Access Journals (Sweden)

    Nikolay Nikolaevich Bogachev

    2014-02-01

    Full Text Available Existence modes of  surface electromagnetic wave on a plasma cylinder, operating modes and characteristics of the plasma antenna were studied in this paper. Solutions of the dispersion equation of surface wave were obtained for a plasma cylinder with finite radius for different plasma density values. Operation modes of the plasma asymmetric dipole antenna with finite length and radius were researched by numerical simulation. The electric field distributions of  the plasma antenna in near antenna field and the radiation pattern were obtained. These characteristics were compared to characteristics of the similar metal antenna. Numerical models verification was carried out by comparing of the counted and measured metal antenna radiation patterns.

  16. Avalanche and streamer mode operation of resistive plate chambers

    International Nuclear Information System (INIS)

    Cardarelli, R.; Makeev, V.; Santonico, R.

    1996-01-01

    A resistive plate chamber was operated at voltages increasing in steps of 200 V over a 3 kV interval and the transition between the avalanche and streamer modes was studied. The avalanche amplitude was observed to be exponentially dependent on the operating voltage up to a value, characteristic of the gas, where the avalanche saturation occurs and delayed streamer signals start to appear. Signal waveforms, charge and timing distributions are reported. (orig.)

  17. Startup methods for single-mode gyrotron operation

    International Nuclear Information System (INIS)

    Whaley, D.R.; Tran, M.Q.; Alberti, S.; Tran, T.M.; Antonsen, T.M.; Tran, C.

    1995-03-01

    Experimental results of startup studies on a 118 GHz TE 22,6 gyrotron are presented and compared with theory. The theoretical excitation regimes of competing modes are computed in the energy-velocity-pitch-angle plane near the operation point. The startup paths through the plane are determined by the time evolution of the beam parameters during the startup phase. These startup paths are modified by changing the anode and cathode voltage rise from zero to their nominal values and are seen to determine the cavity oscillating mode. Experimental results show specifically that competition between the TE 22,6 and TE -19,7 mode can be completely eliminated by using the proper startup method in a case where a typical triode startup results in oscillation in the competing TE -19,7 mode. These new results are shown to be in excellent agreement with theory whose approach is general and therefore applicable to gyrotrons operating in any arbitrary cavity mode. (author) 5 figs., 1 tab., 13 refs

  18. Circuit breaker operation and potential failure modes during an earthquake

    International Nuclear Information System (INIS)

    Lambert, H.E.; Budnitz, R.J.

    1987-01-01

    This study addresses the effect of a strong-motion earthquake on circuit breaker operation. It focuses on the loss of offsite power (LOSP) transient caused by a strong-motion earthquake at the Zion Nuclear Power Plant. This paper also describes the operator action necessary to prevent core melt if the above circuit breaker failure modes occur simultaneously on three 4.16 KV buses. Numerous circuit breakers important to plant safety, such as circuit breakers to diesel generators and engineered safety systems (ESS), must open and/or close during this transient while strong motion is occurring. Potential seismically-induced circuit-breaker failures modes were uncovered while the study was conducted. These failure modes include: circuit breaker fails to close; circuit breaker trips inadvertently; circuit breaker fails to reclose after trip. The causes of these failure modes include: Relay chatter causes the circuit breaker to trip; Relay chatter causes anti-pumping relays to seal-in which prevents automatic closure of circuit breakers; Load sequencer failures. The incorporation of these failure modes as well as other instrumentation and control failures into a limited scope seismic probabilistic risk assessment is also discussed in this paper

  19. Recent progress towards advanced mode of operation on JET

    Energy Technology Data Exchange (ETDEWEB)

    Litaudon, X. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France); Crisanti, F.; Frigione, D. [Association Euratom-ENEA sulla Fusione Centro Ricerche Energia Frascati (Italy)] [and others

    2003-07-01

    This series of slides presents the recent performance of JET concerning ITB (internal transport barrier) operating mode. Pellet refuelling without ITB destruction has been achieved at n{sub eo}/n{sub GW} {approx} 1. A wide reversed shear ITB (3.6 m) has been sustained with mild ELM (edge localized modes) and no apparent impurity accumulation. ITBs have been maintained thanks to a simultaneous optimisation of the q-profile and edge condition, which opens the way for a steady-state ITB.

  20. Single-mode operation of a coiled multimode fiber amplifier

    International Nuclear Information System (INIS)

    Koplow, Jeffrey P.; Kliner, Dahv A. V.; Goldberg, Lew

    2000-01-01

    We report a new approach to obtaining single-transverse-mode operation of a multimode fiber amplifier in which the gain fiber is coiled to induce significant bend loss for all but the lowest-order mode. We demonstrated this method by constructing a coiled amplifier using Yb-doped, double-clad fiber with a core diameter of 25 μm and a numerical aperture of ∼0.1 (V≅7.4) . When the amplifier was operated as an amplified-spontaneous-emission source, the output beam had an M 2 value of 1.09±0.09 ; when seeded at 1064 nm, the slope efficiency was similar to that of an uncoiled amplifier. This technique will permit scaling of pulsed fiber lasers and amplifiers to significantly higher pulse energies and peak powers and cw fiber sources to higher average powers while maintaining excellent beam quality. (c) 2000 Optical Society of America

  1. Single mode operation of a TEA CO2 laser

    International Nuclear Information System (INIS)

    Wada, Kazuhiro; Tunawaki, Yoshiaki; Yamanaka, Masanobu.

    1993-01-01

    Single mode operation of a TEA CO 2 laser was performed by using an optical system of Fox-Smith type. Laser beam was taken out from the cavity by using a beam splitter, and was reflected by a mirror back to the cavity. By inserting a Fabry-Perot etalon between the splitter and the mirror, beat of laser pulses can be removed completly. (author)

  2. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Directory of Open Access Journals (Sweden)

    Dirba J.

    2017-04-01

    Full Text Available The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force or angle ε (angle between rotor direct axis and armature magnetomotive force axis is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  3. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Science.gov (United States)

    Dirba, J.; Lavrinovicha, L.; Dobriyan, R.

    2017-04-01

    The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  4. A novel current mode operating beam counter based on not preamplified HPDs

    CERN Document Server

    Fujiwara, M.C.

    2002-01-01

    A novel system to monitor the intensity and the stability of a bunched beam of $\\simeq 1.2\\times 10^{7}$ antiprotons ($\\bar{p}$s) with a length of $\\simeq$ 250 ns (FWHM) and to measure its trapping efficiency in a Penning trap is described. This system operates parasitically detecting the pions from the annihilation of part of the beam in a degrader. Six plastic scintillators have been coupled from one side to six proximity focused HPDs without preamplifiers and operating in current mode. This device works in the stray field of the ATHENA magnet with no loss of efficiency; the gain can be varied from zero to a few thousands with a precision better than 0.1% and the dynamic range is larger than 8 orders of magnitude. Linearity and stability have been measured up to charge responses of 100 nC, corresponding to the beam completely dumped. The beam counter has been calibrated in two different and independent ways giving consistent results.

  5. Optimal Protection Coordination for Microgrid under Different Operating Modes

    Directory of Open Access Journals (Sweden)

    Ming-Ta Yang

    2013-01-01

    Full Text Available Significant consequences result when a microgrid is connected to a distribution system. This study discusses the impacts of bolted three-phase faults and bolted single line-to-ground faults on the protection coordination of a distribution system connected by a microgrid which operates in utility-only mode or in grid-connected mode. The power system simulation software is used to build the test system. The linear programming method is applied to optimize the coordination of relays, and the relays coordination simulation software is used to verify if the coordination time intervals (CTIs of the primary/backup relay pairs are adequate. In addition, this study also proposes a relays protection coordination strategy when the microgrid operates in islanding mode during a utility power outage. Because conventional CO/LCO relays are not capable of detecting high impedance fault, intelligent electrical device (IED combined with wavelet transformer and neural network is proposed to accurately detect high impedance fault and identify the fault phase.

  6. Mixed-mode Operating System for Real-time Performance

    Directory of Open Access Journals (Sweden)

    M.M. Hasan

    2017-11-01

    Full Text Available The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface (GUI operating system which is typically nonreal-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time events. In this research an i8751 microcontroller-based hardware was used to measure the performance of the system in real-time-only as well as non-real-time-only configurations. The real-time portion is an 486DX-40 IBM PC system running under DOS-based realtime kernel and the non-real-time portion is a Pentium III based system running under Windows NT. It was found that mixed-mode systems performed as good as a typical realtime system and in fact, gave many additional benefits such as simplified/modular programming and load tolerance.

  7. Operation of Ferroelectric Plasma Sources in a Gas Discharge Mode

    International Nuclear Information System (INIS)

    Dunaevsky, A.; Fisch, N.J.

    2004-01-01

    Ferroelectric plasma sources in vacuum are known as sources of ablative plasma, formed due to surface discharge. In this paper, observations of a gas discharge mode of operation of the ferroelectric plasma sources (FPS) are reported. The gas discharge appears at pressures between approximately 20 and approximately 80 Torr. At pressures of 1-20 Torr, there is a transition from vacuum surface discharge to the gas discharge, when both modes coexist and the surface discharges sustain the gas discharge. At pressures between 20 and 80 Torr, the surface discharges are suppressed, and FPS operate in pure gas discharge mode, with the formation of almost uniform plasma along the entire surface of the ceramics between strips. The density of the expanding plasma is estimated to be about 1013 cm-3 at a distance of 5.5 mm from the surface. The power consumption of the discharge is comparatively low, making it useful for various applications. This paper also presents direct measurements of the yield of secondary electron emission from ferroelectric ceramics, which, at low energies of primary electrons, is high and dependent on the polarization of the ferroelectric material

  8. Research on Integrated Control of Microgrid Operation Mode

    Science.gov (United States)

    Cheng, ZhiPing; Gao, JinFeng; Li, HangYu

    2018-03-01

    The mode switching control of microgrid is the focus of its system control. According to the characteristics of different control, an integrated control system is put forward according to the detecting voltage and frequency deviation after switching of microgrid operating mode. This control system employs master-slave and peer-to-peer control. Wind turbine and photovoltaic(PV) adopt P/Q control, so the maximum power output can be achieved. The energy storage will work under the droop control if the system is grid-connected. When the system is off-grid, whether to employ droop control or P/f control is determined by system status. The simulation has been done and the system performance can meet the requirement.

  9. Seismic transmission operator reciprocity - II: impedance-operator symmetry via elastic lateral modes

    Science.gov (United States)

    Thomson, C. J.

    2015-08-01

    The properties of the overburden transmission response are of particular interest for the analysis of reflectivity illumination or blurring in seismic depth imaging. The first step to showing a transmission-operator reciprocity property is to identify the symmetry of the so-called displacement-to-traction operators. The latter are analogous to Dirichlet-to-Neumann operators and they may also be called impedance operators. Their symmetry is deduced here after development of a formal spectral or modal theory of lateral wavefunctions in a laterally heterogeneous generally anisotropic elastic medium. The elastic lateral modes are displacement-traction 6-vectors and they are built from two auxiliary 3-vector lateral-mode bases. These auxiliary modes arise from Hermitian and anti-Hermitian operators, so they have familiar properties such as orthogonality. There is no assumption of down/up symmetry of the elasticity tensor, but basic assumptions are made about the existence and completeness of the elastic modes. A point-symmetry property appears and plays a central role. The 6-vector elastic modes have a symplectic orthogonality property, which facilitates the development of modal expansions for 6-vector functions of the lateral coordinates when completeness is assumed. While the elastic modal theory is consistent with the laterally homogeneous case, numerical work would provide confidence that it is correct in general. An appendix contains an introductory overview of acoustic lateral modes that were studied by other authors, given from the perspective of this new work. A distinction is drawn between unit normalization of scalar auxiliary modes and a separate energy-flux normalization of 2-vector acoustic modes. Neither is crucial to the form of acoustic pressure-to-velocity or impedance operators. This statement carries over to the elastic case for the 3-vector auxiliary- and 6-vector elastic-mode normalizations. The modal theory is used to construct the kernel of the

  10. Mevva ion source operated in purely gaseous mode

    International Nuclear Information System (INIS)

    Yushkov, G.Y.; MacGill, R.A.; Brown, I. G.

    2003-01-01

    We have operated a vacuum arc ion source in such a way as to form beams of purely gaseous ions. The vacuum arc configuration that is conventionally used to produce intense beams of metal ions was altered so as to form gaseous ion beams, with only minimal changes to the external circuitry and no changes at all internally to the ion source. In our experiments we formed beams from oxygen (O + and O 2 + ), nitrogen (N + and N 2 + ), argon (Ar + ) and carbon dioxide (C + , CO 2 + , O + and O 2 + ) at extraction voltage of 2 to 50 kV. We used a pulsed mode of operation, with beam pulses approximately 50 milliseconds long and repetition rate 10 pulses per second, for a duty cycle of about 50%. Downstream ion beam current as measured by a 5 cm diameter Faraday cup was typically 0.5 mA pulse or about 250 (micro)A time averaged. This time averaged beam current is very similar to that obtained for metal ions when the source is operated in the usual vacuum arc mode. Here we describe the modifications made to the source and the results of our investigations

  11. 75 FR 65278 - Pamlico Sound and Adjacent Waters, NC; Danger Zones for Marine Corps Operations

    Science.gov (United States)

    2010-10-22

    ... comments. E-mail: david.b.olson@usace.army.mil . Include the docket number COE-2010-0037 in the subject line of the message. Mail: U.S. Army Corps of Engineers, Attn: CECW-CO (David B. Olson), 441 G Street... CONTACT: Mr. David Olson, Headquarters, Operations and Regulatory Community of Practice, Washington, DC at...

  12. Mixed - mode Operating System for Real - time Performance

    Directory of Open Access Journals (Sweden)

    Hasan M. M.

    2017-11-01

    Full Text Available The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface(GUIoperating system which is typicallynon-real-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time events. In this research an i8751 microcontroller-based hardware was used to measure the performance of the system in real-time-only as well as non-real-time-only configurations. The real-time portion is an 486DX-40 IBM PC system running under DOS-based real-time kernel and the non-real-time portion is a Pentium IIIbased system running under Windows NT. It was found that mixed-mode systems performed as good as a typical real-time system and in fact, gave many additional benefits such as simplified/modular programming and load tolerance.

  13. Research on operation mode of abrasive grain during grinding

    Science.gov (United States)

    Ivanova, T. N.; Dement’ev, V. B.; Nikitina, O. V.

    2018-03-01

    The processing of materials by cutting with an abrasive tool is carried out by means of thousands of grains bonded together as a single whole. The quality of the abrasive tool is defined by cutting properties of abrasive grains and depends on features of spreading the temperature field in time and in the abrasive grain volume. Grains are exposed to heating and cooling during work. It leads to undesired effects such as a decrease of durability of grain retention in the binder, hardness, intensification of diffusion and oxidation processes between the binder and the grain, the occurrence of considerable temperature stresses in the grain itself. The obtained equation which allows calculation of temperature field of grain for one rotation of grinding wheel shows that the temperature of the wheel depends on grinding modes and thermophysical properties of abrasive material. Thus, as the time of contact of grain with processed material increases, the temperature in the cutting area rises. As thermophysical properties increase, the temperature in cutting area decreases. Thermal working conditions are determined to be different from each other depending on contact time of the grain and the material. For example, in case of creep-feed grinding, the peak value of temperature is higher than during multistep grinding; the depth of expansion is greater. While the speed of the thermal process in creep-feed grinding is 2-3 times lower than in multistep grinding, the gradient reduces 3-4 times. The analysis of machining methods shows that creep-feed grinding ensures greater depth of grain heating, a smaller heating rate and a reduced velocity gradient. It causes a decrease of probable allotropic modifications and prevents from occurring of heat strokes - cracking of grains due to high temperature falls. Consequently, it is necessary to employ creep-feed grinding to increase the efficiency of abrasive tool employing. Three operation modes of grinding wheel including blunting, full

  14. Development of Abnormal Operating Strategies for Station Blackout in Shutdown Operating Mode in Pressurized Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Duk-Joo; Lee, Seung-Chan; Sung, Je-Joong; Ha, Sang-Jun [KHNP CRI, Daejeon (Korea, Republic of); Hwang, Su-Hyun [FNC Tech. Co., Yongin (Korea, Republic of)

    2016-10-15

    Loss of all AC power is classified as one of multiple failure accident by regulatory guide of Korean accident management program. Therefore we need develop strategies for the abnormal operating procedure both of power operating and shutdown mode. This paper developed abnormal operating guideline for loss of all AC power by analysis of accident scenario in pressurized water reactor. This paper analyzed the loss of ultimate heat sink (LOUHS) in shutdown operating mode and developed the operating strategy of the abnormal procedure. Also we performed the analysis of limiting scenarios that operator actions are not taken in shutdown LOUHS. Therefore, we verified the plant behavior and decided operator action to taken in time in order to protect the fuel of core with safety. From the analysis results of LOUHS, the fuel of core maintained without core uncovery for 73 minutes respectively for opened RCS states after the SBO occurred. Therefore, operator action for the emergency are required to take in 73 minutes for opened RCS state. Strategy is to cooldown by using spent fuel pool cooling system. This method required to change the plant design in some plant. In RCS boundary closed state, first abnormal operating strategy in shutdown LOUHS is first abnormal operating strategy in shutdown LOUHS is to remove the residual heat of core by steam dump flow and auxiliary feedwater of SG.

  15. Study on a New Operational Mode of Economic Operation of Islanded Microgrids Using Electric Springs

    Directory of Open Access Journals (Sweden)

    Zhao Zhiyu

    2018-01-01

    Full Text Available With the increasing penetration of intermittent renewable energy sources (RESs into microgrids, the original operation mode of power generation determined by load demand faces severe challenges due to the uncertainties of the RESs power output. The electric springs(ESs, as an emerging technology has been verified to be effective in enabling load demand to follow power generation and stabilizing fluctuation of RESs output. This paper presents a new mode of economic operation for island microgrids including non-critical loads with embedded electric springs. Its connotation includes that i the capacity of energy storage can be reduced through the interaction of the energy storage system (ESS and the electric springs, ii the electric springs reduce the stress of peak load regulation and operational cost and iii the demand of microgrids system for ramping ability of generation units is reduced with the buffer of the electric springs. Numerical results show that the coordinated operation between electric springs and energy storage system of microgrids can bring down the investment cost for the ESS and short-term operational cost in the aspect of economic dispatch, reducing requirements for the capacity and ramp ability of the energy storage system in microgrids. Energy buffering can be achieved with lower cost and the load demand can follow power generation in the new operational mode of islanded microgrids using electric springs.

  16. Edge localized mode physics and operational aspects in tokamaks

    International Nuclear Information System (INIS)

    Becoulet, M; Huysmans, G; Sarazin, Y; Garbet, X; Ghendrih, Ph; Rimini, F; Joffrin, E; Litaudon, X; Monier-Garbet, P; Ane, J-M; Thomas, P; Grosman, A; Parail, V; Wilson, H; Lomas, P; Vries, P de; Zastrow, K-D; Matthews, G F; Lonnroth, J; Gerasimov, S; Sharapov, S; Gryaznevich, M; Counsell, G; Kirk, A; Valovic, M; Buttery, R; Loarte, A; Saibene, G; Sartori, R; Leonard, A; Snyder, P; Lao, L L; Gohil, P; Evans, T E; Moyer, R A; Kamada, Y; Chankin, A; Oyama, N; Hatae, T; Asakura, N; Tudisco, O; Giovannozzi, E; Crisanti, F; Perez, C P; Koslowski, H R; Eich, T; Sips, A; Horton, L; Hermann, A; Lang, P; Stober, J; Suttrop, W; Beyer, P; Saarelma, S

    2003-01-01

    Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely the high confinement regimes, that is, H-modes and advanced scenarios. Theoretical approaches to ELM physics, from a linear ideal magnetohydrodynamic (MHD) stability analysis to non-linear transport models with ELMs are discussed with respect to experimental observations, in particular the fast collapse of pedestal pressure profiles, magnetic measurements and scrape-off layer transport during ELMs. High confinement regimes with different types of ELMs are addressed in this paper in the context of development of operational scenarios for ITER. The key parameters that have been identified at present to reduce the energy losses in Type I ELMs are operation at high density, high edge magnetic shear and high triangularity. However, according to the present experimental scaling for the energy losses in Type I ELMs, the extrapolation of such regimes for ITER leads to unacceptably large heat loads on the divertor target plates exceeding the material limits. High confinement H-mode scenarios at high triangularity and high density with small ELMs (Type II), mixed regimes (Type II and Type I) and combined advanced regimes at high beta p are discussed for present-day tokamaks. The optimum combination of high confinement and small MHD activity at the edge in Type II ELM scenarios is of interest to ITER. However, to date, these regimes have been achieved in a rather narrow operational window and far from ITER parameters in terms of collisionality, edge safety factor and beta p . The compatibility of the alternative internal transport barrier (ITB) scenario with edge pedestal formation and ELMs is also addressed. Edge physics issues related to the possible combination of small benign ELMs (Type III, Type II ELMs, quiescent double barrier) and high performance ITBs are discussed for present-day experiments (JET, JT-60U, DIII-D) in

  17. Edge localized mode physics and operational aspects in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Becoulet, M [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Huysmans, G [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Sarazin, Y [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Garbet, X [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Ghendrih, Ph [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Rimini, F [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Joffrin, E [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Litaudon, X [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Monier-Garbet, P [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Ane, J-M [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Thomas, P [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Grosman, A [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Parail, V [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Wilson, H [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Lomas, P [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Vries, P de[Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Zastrow, K-D [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Matthews, G F [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Lonnroth, J [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Gerasimov, S [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom)] [and others

    2003-12-01

    Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely the high confinement regimes, that is, H-modes and advanced scenarios. Theoretical approaches to ELM physics, from a linear ideal magnetohydrodynamic (MHD) stability analysis to non-linear transport models with ELMs are discussed with respect to experimental observations, in particular the fast collapse of pedestal pressure profiles, magnetic measurements and scrape-off layer transport during ELMs. High confinement regimes with different types of ELMs are addressed in this paper in the context of development of operational scenarios for ITER. The key parameters that have been identified at present to reduce the energy losses in Type I ELMs are operation at high density, high edge magnetic shear and high triangularity. However, according to the present experimental scaling for the energy losses in Type I ELMs, the extrapolation of such regimes for ITER leads to unacceptably large heat loads on the divertor target plates exceeding the material limits. High confinement H-mode scenarios at high triangularity and high density with small ELMs (Type II), mixed regimes (Type II and Type I) and combined advanced regimes at high beta{sub p} are discussed for present-day tokamaks. The optimum combination of high confinement and small MHD activity at the edge in Type II ELM scenarios is of interest to ITER. However, to date, these regimes have been achieved in a rather narrow operational window and far from ITER parameters in terms of collisionality, edge safety factor and beta{sub p}. The compatibility of the alternative internal transport barrier (ITB) scenario with edge pedestal formation and ELMs is also addressed. Edge physics issues related to the possible combination of small benign ELMs (Type III, Type II ELMs, quiescent double barrier) and high performance ITBs are discussed for present-day experiments (JET, JT-60U

  18. Overview of long pulse H-mode operation on EAST

    Science.gov (United States)

    Gong, X.; Garofalo, A. M.; Wan, B.; Li, J.; Qian, J.; Li, E.; Liu, F.; Zhao, Y.; Wang, M.; Xu, H.; EAST Team

    2017-10-01

    The EAST research program aims to demonstrate steady-state long-pulse high-performance H-mode operations with ITER-like poloidal configuration and RF-dominated heating schemes. In the recent experimental campaign, a long pulse fully non-inductive H-mode discharge lasting over 100 seconds using the upper ITER-like tungsten divertor has been achieved in EAST. This scenario used only RF heating and current drive, but also benefitted from an integrated control of the wall conditioning, plasma configuration, divertor heat flux, particle exhaust, impurity management and superconducting coils safety. Maintaining effective coupling of multiple RF heating and current drive sources on EAST is a critical ingredient. This long pulse discharge had good energy confinement, H98,y2 1.1-1.2, and all of the plasma parameters reach a true steady-state. Power balance indicates that the confinement improvement is due partly to a significantly reduced core electron transport inside minor radius rho<0.4. This work was supported by the National Magnetic Confinement Fusion Program of China Contract No. 2015GB10200 and the US Department of Energy Contract No. DE-SC0010685.

  19. Modes of mechanical ventilation for the operating room.

    Science.gov (United States)

    Ball, Lorenzo; Dameri, Maddalena; Pelosi, Paolo

    2015-09-01

    Most patients undergoing surgical procedures need to be mechanically ventilated, because of the impact of several drugs administered at induction and during maintenance of general anaesthesia on respiratory function. Optimization of intraoperative mechanical ventilation can reduce the incidence of post-operative pulmonary complications and improve the patient's outcome. Preoxygenation at induction of general anaesthesia prolongs the time window for safe intubation, reducing the risk of hypoxia and overweighs the potential risk of reabsorption atelectasis. Non-invasive positive pressure ventilation delivered through different interfaces should be considered at the induction of anaesthesia morbidly obese patients. Anaesthesia ventilators are becoming increasingly sophisticated, integrating many functions that were once exclusive to intensive care. Modern anaesthesia machines provide high performances in delivering the desired volumes and pressures accurately and precisely, including assisted ventilation modes. Therefore, the physicians should be familiar with the potential and pitfalls of the most commonly used intraoperative ventilation modes: volume-controlled, pressure-controlled, dual-controlled and assisted ventilation. Although there is no clear evidence to support the advantage of any one of these ventilation modes over the others, protective mechanical ventilation with low tidal volume and low levels of positive end-expiratory pressure (PEEP) should be considered in patients undergoing surgery. The target tidal volume should be calculated based on the predicted or ideal body weight rather than on the actual body weight. To optimize ventilation monitoring, anaesthesia machines should include end-inspiratory and end-expiratory pause as well as flow-volume loop curves. The routine administration of high PEEP levels should be avoided, as this may lead to haemodynamic impairment and fluid overload. Higher PEEP might be considered during surgery longer than 3 h

  20. Suppression and nonlinear excitation of parasitic modes in second harmonic gyrotrons operating in a very high order mode

    International Nuclear Information System (INIS)

    Nusinovich, Gregory S.; Pu, Ruifeng; Granatstein, Victor L.

    2015-01-01

    In recent years, there was an active development of high-power, sub-terahertz (sub-THz) gyrotrons for numerous applications. For example, a 0.67 THz gyrotron delivering more than 200 kW with about 20% efficiency was developed. This record high efficiency was achieved because the gyrotron operated in a high-order TE 31,8 -mode with the power of ohmic losses less than 10% of the power of outgoing radiation. That gyrotron operated at the fundamental cyclotron resonance, and a high magnetic field of about 27 T was created by a pulse solenoid. For numerous applications, it is beneficial to use gyrotrons at cyclotron harmonics which can operate in available cryomagnets with fields not exceeding 15 T. However, typically, the gyrotron operation at harmonics faces severe competition from parasitic modes at the fundamental resonance. In the present paper, we consider a similar 0.67 THz gyrotron designed for operation in the same TE 31,8 -mode, but at the second harmonic. We focus on two nonlinear effects typical for interaction between the fundamental and second harmonic modes, viz., the mode suppression and the nonlinear excitation of the mode at the fundamental harmonic by the second harmonic oscillations. Our study includes both the analytical theory and numerical simulations performed with the self-consistent code MAGY. The simulations show that stable second harmonic operation in the TE 31,8 mode is possible with only modest sacrifice of efficiency and power

  1. The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Garofalo, A. M., E-mail: garofalo@fusion.gat.com; Burrell, K. H.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Turnbull, A. D. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Eldon, D.; Grierson, B. A.; Solomon, W. M. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Hanson, J. M. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Holland, C. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Huijsmans, G. T. A.; Liu, F.; Loarte, A. [ITER Organization, Route de Vinon sur Verdon, 13067 St Paul Lez Durance (France); Zeng, L. [University of California Los Angeles, P.O. Box 957099, Los Angeles, California 90095-7099 (United States)

    2015-05-15

    For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

  2. Multi-mode operations for on-line uninterruptible power supply

    DEFF Research Database (Denmark)

    Lu, Jinghang; Savaghebi, Mehdi; Guan, Yajuan

    2018-01-01

    In this paper, the multi-mode operation of the on-line UPS system is investigated and corresponding control strategies are proposed. The proposed control strategies are able to achieve the seamless transition in traditional normal mode, PV-aided normal mode, enhanced eco-mode and burn-in test mod...

  3. ANALYSIS OF OPTIMUM OPERATING MODES OF POWER TRANSFORMERS UNDER OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. V. Khomenko

    2016-12-01

    Full Text Available Purpose. The study of parallel operation optimal modes of transformer equipment for a variety of operating conditions: same or different types of transformers, with or without reactive power flows. Methodology. Losses of energy in transformers make 30 % of all losses. Therefore the choice of the economically justified parallel operation of transformers is effective action to reduce losses. Typically, in the calculations of reactive power flows in the transformers are not taken into account. It is interesting to analyze the optimal operating conditions of transformers with and without reactive power flows. Results. Calculations for transformers in distribution networks showed that the inclusion of reactive power flows in transformers significant impact on the calculated optimum regimes of transformers.

  4. New information technologies in operative control of modes in regional electrical power systems

    OpenAIRE

    ANDREY D. TEVJASHEV; TATJANA B. TIMOFEEVA

    2003-01-01

    The problem of development of software for management of modes in electrical power systems in connection with casual character of a load in network is considered. The stochastic mathematical model of a system for operating control of modes in regional electrical power systems is offered. The methods for problem solving of operating control and operating planning of operational modes in regional electrical power systems are developed. The application of the developed models and methods will al...

  5. Squeeze strengthening of magnetorheological fluids using mixed mode operation

    Science.gov (United States)

    Becnel, A. C.; Sherman, S. G.; Hu, W.; Wereley, N. M.

    2015-05-01

    This research details a novel method of increasing the shear yield stress of magnetorheological fluids by combining shear and squeeze modes of operation to manipulate particle chain structures, so-called squeeze strengthening. Using a custom built Searle cell magnetorheometer, which is a model device emulating a rotary magnetorheological energy absorber (MREA), the contribution of squeeze strengthening to the total controllable yield force is experimentally investigated. Using an eccentric rotating inner cylinder, characterization data from large (1 mm) and small (0.25 mm) nominal gap geometries are compared to investigate the squeeze strengthening effect. Details of the experimental setup and method are presented, and a hybrid model is used to explain experimental trends. This study demonstrates that it is feasible, utilizing squeeze strengthening to increase yield stress, to either (1) design a rotary MREA of a given volume to achieve higher energy absorption density (energy absorbed normalized by active fluid volume), or (2) reduce the volume of a given rotary MREA to achieve the same energy absorption density.

  6. Low-bending loss and single-mode operation in few-mode optical fiber

    Science.gov (United States)

    Yin, Ping; Wang, Hua; Chen, Ming-Yang; Wei, Jin; Cai, Zhi-Min; Li, Lu-Ming; Yang, Ji-Hai; Zhu, Yuan-Feng

    2016-10-01

    The technique of eliminating the higher-order modes in a few-mode optical fiber is proposed. The fiber is designed with a group of defect modes in the cladding. The higher-order modes in the fiber can be eliminated by bending the fiber to induce strong coupling between the defect modes and the higher-order modes. Numerical simulation shows the bending losses of the LP01 mode are lower than 1.5×10-4 dB/turn for the wavelength shorter than 1.625 μm. The proposed fiber can be bent multiple turns at small bending radius which are preferable for FTTH related applications.

  7. Optimal Control of Micro Grid Operation Mode Seamless Switching Based on Radau Allocation Method

    Science.gov (United States)

    Chen, Xiaomin; Wang, Gang

    2017-05-01

    The seamless switching process of micro grid operation mode directly affects the safety and stability of its operation. According to the switching process from island mode to grid-connected mode of micro grid, we establish a dynamic optimization model based on two grid-connected inverters. We use Radau allocation method to discretize the model, and use Newton iteration method to obtain the optimal solution. Finally, we implement the optimization mode in MATLAB and get the optimal control trajectory of the inverters.

  8. Based on Intelligent Robot of E-business Distribution Center Operation Mode Research

    Directory of Open Access Journals (Sweden)

    Li Juntao

    2016-01-01

    Full Text Available According to E-business distribution center operation mode in domestic and advanced experience drawing lessons at home and abroad, this paper based on intelligent robot researches E-business distribution center operation mode. And it proposes the innovation logistics storage in E-business and sorting integration system, and elaborates its principle, characteristics, as well as studies its business mode and logistics process, and its parameters and working mode of AGV equipment.

  9. Online probabilistic operational safety assessment of multi-mode engineering systems using Bayesian methods

    International Nuclear Information System (INIS)

    Lin, Yufei; Chen, Maoyin; Zhou, Donghua

    2013-01-01

    In the past decades, engineering systems become more and more complex, and generally work at different operational modes. Since incipient fault can lead to dangerous accidents, it is crucial to develop strategies for online operational safety assessment. However, the existing online assessment methods for multi-mode engineering systems commonly assume that samples are independent, which do not hold for practical cases. This paper proposes a probabilistic framework of online operational safety assessment of multi-mode engineering systems with sample dependency. To begin with, a Gaussian mixture model (GMM) is used to characterize multiple operating modes. Then, based on the definition of safety index (SI), the SI for one single mode is calculated. At last, the Bayesian method is presented to calculate the posterior probabilities belonging to each operating mode with sample dependency. The proposed assessment strategy is applied in two examples: one is the aircraft gas turbine, another is an industrial dryer. Both examples illustrate the efficiency of the proposed method

  10. Operability test procedure for the Rotary Mode Core Sampling System Exhausters 3 and 4

    International Nuclear Information System (INIS)

    WSaldo, E.J.

    1995-01-01

    This document provides a procedure for performing operability testing of the Rotary Mode Core Sampling System Exhausters 3 ampersand 4. Upon completion of testing activities an operability testing report will be issued

  11. Symplectic Group Representation of the Two-Mode Squeezing Operator in the Coherent State Basis

    Science.gov (United States)

    Fan, Hong-Yi; Chen, Jun-Hua

    2003-11-01

    We find that the coherent state projection operator representation of the two-mode squeezing operator constitutes a loyal group representation of symplectic group, which is a remarkable property of the coherent state. As a consequence, the resultant effect of successively applying two-mode squeezing operators are equivalent to a single squeezing in the two-mode Fock space. Generalization of this property to the 2n-mode case is also discussed. The project supported by National Natural Science Foundation of China under Grant No. 10575057

  12. MIMO Channel Capacity for Handsets in Data Mode Operation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan; Bonev, Ivan Bonev

    2010-01-01

    The current paper concerns realistic evaluation of the capacity of the MIMO channel between a BS and handheld device, such as a PDA or smart phone, held in front of the user’s body (data mode). The work is based on measurements of the MIMO channel between two widely separated BSs in a micro...

  13. Plasma parameters for alternate operating modes of TIBER-II

    International Nuclear Information System (INIS)

    Fenstermacher, M.E.; Devoto, R.S.; Logan, B.G.; Perkins, L.J.

    1987-01-01

    Parameters for operating points of TIBER-II, different from the baseline steady-state operation, are presented. These results have been generated with the MUMAK tokamak power balance code. Pulsed ignited and high performance steady-state operating points are described. 20 refs

  14. Control Modes in International Service Operations: The Propensity to Franchise

    OpenAIRE

    Karin Fladmoe-Lindquist; Laurent L. Jacque

    1995-01-01

    What determines a service firm's organizational choice between equity-based control and franchising? This question, which has elicited some theoretical answers and a few empirical tests in a domestic setting, has never been addressed in an international context before. This study explains the mode of control chosen in terms of a theoretical framework which borrows from agency theory and transaction cost analysis. The propensity to franchise internationally was found to be directly related to ...

  15. Bevalac versatility: Operations achievements in the multi-tasking mode

    International Nuclear Information System (INIS)

    Lothrop, F.; Alonso, J.; Miller, R.; Tekawa, M.

    1989-03-01

    Demand for relativistic heavy ion beams at the Bevalac has increased dramatically in the past two years. To keep pace, the Bevalac make use of five injectors, precise guide field control, preset beam transport line tunes, nine nuclear science target areas, and three biology/radiotherapy areas, along with elegant control computer algorithms, to achieve high operating efficiency. Routine operation includes as many as ten ion/energy/beamline changes per day, 15 major nuclear science experiments each year, radiotherapy on nearly a daily basis, with biology experiments operating biweekly. High operating efficiency and low failure rates combine to produce high annual research hours. 12 refs., 2 figs

  16. Novel operation mode for eliminating influence of inclination angle and friction in atomic force microscopy

    International Nuclear Information System (INIS)

    Wang, Fei; Wang, Yueyu; Zhou, Faquan; Zhao, Xuezeng

    2010-01-01

    The accuracy of topography imaging in contact force mode of atomic force microscopy (AFM) depends on the one-to-one corresponding relationship between the cantilever deflection and the tip-sample distance, whereas such a relationship cannot be always achieved in the presence of friction and incline angle of sample surface. Recently, we have developed a novel operation mode in which we keep the van der Waals force as constant instead of the applied normal force, to eliminate the effect of inclination angle and friction on topography imaging in the contact force mode. We have improved our AFM to enable the new operation mode for validation. Comparative experiments have been performed and the results have shown that the effect of friction and inclination angle on topography imaging in contact mode of AFM can be eliminated or at least decreased effectively by working in the new operation mode we present.

  17. OPTIMIZATION OF AGGREGATION AND SEQUENTIAL-PARALLEL EXECUTION MODES OF INTERSECTING OPERATION SETS

    Directory of Open Access Journals (Sweden)

    G. М. Levin

    2016-01-01

    Full Text Available A mathematical model and a method for the problem of optimization of aggregation and of sequential- parallel execution modes of intersecting operation sets are proposed. The proposed method is based on the two-level decomposition scheme. At the top level the variant of aggregation for groups of operations is selected, and at the lower level the execution modes of operations are optimized for a fixed version of aggregation.

  18. Influence of Missile Fusillade Engagement Mode on Operation Efficiency

    Institute of Scientific and Technical Information of China (English)

    BU Xian-jin; REN Yi-guang; SHA Ji-chang

    2008-01-01

    Shoot efficiency is one of the most important evaluation indexes of the operation efficiency of weapon system. In this paper, based on definitions of the probability and the expected number of missed attacking missiles, the expected numbers of anti-missiles and attacking missiles hit by single anti-missile, fusillade mechanism of multi-missile is analyzed systematically. The weapon operation efficiency in various engagement patterns is also studied. The results show that double missiles fusillade is the most feasible manner for increasing the weapon operation efficiency.

  19. Control software architecture and operating modes of the Model M-2 maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Satterlee, P.E. Jr.; Martin, H.L.; Herndon, J.N.

    1984-04-01

    The Model M-2 maintenance system is the first completely digitally controlled servomanipulator. The M-2 system allows dexterous operations to be performed remotely using bilateral force-reflecting master/slave techniques, and its integrated operator interface takes advantage of touch-screen-driven menus to allow selection of all possible operating modes. The control system hardware for this system has been described previously. This paper describes the architecture of the overall control system. The system's various modes of operation are identified, the software implementation of each is described, system diagnostic routines are described, and highlights of the computer-augmented operator interface are discussed. 3 references, 5 figures.

  20. Control software architecture and operating modes of the Model M-2 maintenance system

    International Nuclear Information System (INIS)

    Satterlee, P.E. Jr.; Martin, H.L.; Herndon, J.N.

    1984-04-01

    The Model M-2 maintenance system is the first completely digitally controlled servomanipulator. The M-2 system allows dexterous operations to be performed remotely using bilateral force-reflecting master/slave techniques, and its integrated operator interface takes advantage of touch-screen-driven menus to allow selection of all possible operating modes. The control system hardware for this system has been described previously. This paper describes the architecture of the overall control system. The system's various modes of operation are identified, the software implementation of each is described, system diagnostic routines are described, and highlights of the computer-augmented operator interface are discussed. 3 references, 5 figures

  1. An overmoded relativistic backward wave oscillator with efficient dual-mode operation

    International Nuclear Information System (INIS)

    Xiao, Renzhen; Li, Jiawei; Bai, Xianchen; Song, Zhimin; Teng, Yan; Ye, Hu; Li, Xiaoze; Sun, Jun; Chen, Changhua; Zhang, Xiaowei

    2014-01-01

    A dual-mode operation mechanism in an overmoded relativistic backward wave oscillator is presented. The electron beam interacts with the −1st space harmonic of TM 01 mode synchronously in the slow wave structure. Then the backward propagating TM 01 mode is converted to the forward propagating TM 02 mode. As the phase velocity of the volume harmonic of TM 02 mode is about twice that of the surface harmonic of TM 01 mode, the TM 02 mode also plays an important role in the high-power microwave generation. Particle-in-cell simulation shows that an efficiency of 48% and a significant improvement of the power capacity have been obtained

  2. Seven Operation Modes and Simulation Models of Solar Heating System with PCM Storage Tank

    Directory of Open Access Journals (Sweden)

    Juan Zhao

    2017-12-01

    Full Text Available A physical model and dynamic simulation models of a solar phase-change heat storage heating system with a plate solar collector, phase-change material (PCM storage tank, plate heat exchanger, and auxiliary heat sources were established. A control strategy and numerical models for each of seven different operation modes that cover the entire heating season of the system were developed for the first time. The seven proposed operation modes are Mode 1: free cooling; Mode 2: reservation of heat absorbed by the solar collector in the PCM storage tank when there is no heating demand; Mode 3: direct supply of the heating demand by the solar collector; Mode 4: use of the heat absorbed by the solar collector to meet the heating demands, with the excess heat stored in the PCM storage tank; Mode 5: use of heat stored in the PCM storage tank to meet the heating demands, Mode 6: combined use of heat stored in the PCM storage tank and the auxiliary heating sources to meet the heating demands; and Mode 7: exclusive use of the auxiliary heat sources in order to meet the heating demands. Mathematical models were established for each of the above seven operation modes, taking into consideration the effects of the outdoor meteorological parameters and terminal load on the heating system. The real-time parameters for the entire heating season of the system with respect to the different operation modes can be obtained by solving the simulation models, and used as reference for the optimal design and operation of the actual system.

  3. THE OPERATION MODES OPTIMIZATION OF THE NEUTRAL DISTRIBUTION NETWORKS

    Directory of Open Access Journals (Sweden)

    F. P. Shkarbets

    2009-03-01

    Full Text Available The variants of grounding the neutral wire of electric networks are considered and the recommendations are presented on increasing the level of operational reliability and electric safety of distribution networks with 6 kV voltage on the basis of limitation and suppression of transitional processes at asymmetrical damages.

  4. Novel operation and control modes for series-resonant converters

    NARCIS (Netherlands)

    Haan, de S.W.H.; Huisman, H.

    1985-01-01

    A series-resonant converter (SRC) able to generate an output voltage either lower or higher than the source voltage is described. Moreover, a novel control scheme is presented which renders two degrees of freedom for control and which guarantees symmetrical steady-state waveforms in all operation

  5. A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls.

    Science.gov (United States)

    Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning

    2016-03-01

    Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  6. A fluid-coupled transmitting CMUT operated in collapse mode : Semi-analytic modeling and experiments

    NARCIS (Netherlands)

    Pekař, Martin; van Nispen, Stephan H.M.; Fey, Rob H.B.; Shulepov, Sergei; Mihajlović, Nenad; Nijmeijer, Henk

    2017-01-01

    An electro-mechanical, semi-analytic, reduced-order (RO) model of a fluid-loaded transmitting capacitive-micromachined ultrasound transducer (CMUT) operated in collapse mode is developed. Simulation of static deflections, approximated by a linear combination of six mode shapes, are benchmarked

  7. New operational modes for the Ta2O5-based electrolyte conductance cell

    NARCIS (Netherlands)

    Olthuis, Wouter; Smith, A.; van der Zalm, R.A.J.; Bergveld, Piet

    1994-01-01

    Based on the recently presented conductance cell, two specific operational modes are proposed. In the oscillator mode, the conductivity of the electrolyte determines the frequency of an oscillator, experimentally obtaining a shift from 10 to 27 kHz for a KCl concentration range from 0.5 to 100 mM.

  8. Extrap mode operation on Extrap T1-U

    International Nuclear Information System (INIS)

    Scheffel, J.; Brzozowski, J.; Hellblom, G.; Hoerling, P.; Welander, A.

    1995-02-01

    An extensive series of experiments in the Extrap mode has been carried out on Extrap T1-U in an attempt to obtain hot, collisionless discharges. Performance has, however, been limited to low temperatures (≤15 eV) and low currents (≤20 kA) at high loop voltages ≤1.4 kV, leading to energy confinement times of only a few μs or Alfven times. The discharge length is typically of order >100 Alfven times. The poor confinement is attributed to the absence of an axial magnetic field, generating strong instability- induced fluctuations and related transport in the core plasma. A turbulence core plasma transport model is suggested, based on theoretical evidence of linear instability in the kinetic regime. Experiments show that nonlinear saturation prevents the discharge from quenching on a time scale of a few Alfven times. Relaxation to RFP-like states is prevented from by a sufficiently strong octupole magnetic field. Edge transport appears to be strongly influenced by particle diffusion and heat conduction along open field lines (X-points) to the wall. 43 refs, 11 figs

  9. High-intensity pulsed beam source with tunable operation mode

    Science.gov (United States)

    Nashilevskiy, A. V.; Kanaev, G. G.; Ezhov, V. V.; Shamanin, V. I.

    2017-05-01

    The report presents the design of an electron and an ion pulsed accelerator. The powerful high-voltage pulse generator of the accelerator and the vacuum bushing insulator is able to change the polarity of the output voltage. The low-inductance matching transformer provides an increase in the DFL output impedance by 4 times. The generator based on a high voltage pulse transformer and a pseudo spark switch is applied for DFL charging. The high-impedance magnetically insulated focusing diode with Br magnetic field and the “passive” anode was used to realize the ion beam generation mode. The plasma is formed on the surface of the anode caused by an electrical breakdown at the voltage edge pulse; as a result, the carbon ion and proton beam is generated. This beam has the following parameters: the current density is about 400 A/cm2 (in focus): the applied voltage is up to 450 kV. The accelerator is designed for the research on the interaction of the charged particle pulsed beams with materials and for the development of technological processes of a material modification.

  10. Automatic and manual operation modes of the TFTR maintenance manipulator

    International Nuclear Information System (INIS)

    Boehme, G.; Gumb, L.; Lotz, E.; Mueller, G.; Selig, M.

    1987-01-01

    The remote in-vessel operations scheduled to maintain the TFTR at Princeton, NJ, USA, comprise inspection, calibration, cleaning and protective tile replacement. The environmental conditions inside the torus vessel are ultra high vacuum, moderate γ-radiation and 150 0 C temperature of the vessel structure. The Princeton Plasma Physics Laboratory (PPPL) and KfK are jointly developing a maintenance manipulator (MM) which can perform these tasks. (orig./HP)

  11. APET methodology for Defense Waste Processing Facility: Mode C operation

    International Nuclear Information System (INIS)

    Taylor, R.P. Jr.; Massey, W.M.

    1995-04-01

    Safe operation of SRS facilities continues to be the highest priority of the Savannah River Site (SRS). One of these facilities, the Defense Waste Processing Facility or DWPF, is currently undergoing cold chemical runs to verify the design and construction preparatory to hot startup in 1995. The DWPFF is a facility designed to convert the waste currently stored in tanks at the 200-Area tank farm into a form that is suitable for long term storage in engineered surface facilities and, ultimately, geologic isolation. As a part of the program to ensure safe operation of the DWPF, a probabilistic Safety Assessment of the DWPF has been completed. The results of this analysis are incorporated into the Safety Analysis Report (SAR) for DWPF. The usual practice in preparation of Safety Analysis Reports is to include only a conservative analysis of certain design basis accidents. A major part of a Probabilistic Safety Assessment is the development and quantification of an Accident Progression Event Tree or APET. The APET provides a probabilistic representation of potential sequences along which an accident may progress. The methodology used to determine the risk of operation of the DWPF borrows heavily from methods applied to the Probabilistic Safety Assessment of SRS reactors and to some commercial reactors. This report describes the Accident Progression Event Tree developed for the Probabilistic Safety Assessment of the DWPF

  12. Active pixel image sensor with a winner-take-all mode of operation

    Science.gov (United States)

    Yadid-Pecht, Orly (Inventor); Fossum, Eric R. (Inventor); Mead, Carver (Inventor)

    2003-01-01

    An integrated CMOS semiconductor imaging device having two modes of operation that can be performed simultaneously to produce an output image and provide information of a brightest or darkest pixel in the image.

  13. Ship operation and failure mode analysis using a maneuver simulator

    Science.gov (United States)

    Cabrerizo-Morales, Miguel Angel; Molina, Rafael; de los Santos, Francisco; Camarero, Alberto

    2013-04-01

    In a ship or floating structure operation the agents that contribute to the systems behaviour are not only those derived from fluid-structure interaction, but also the ones linked to mooring-control line set-up evolution and human interaction. Therefore, the analysis of such systems is affected by boundary conditions that change during a complete operation. Frequently, monitoring techniques in laboratory (model) and field (prototype) are based in different instrumental techniques adding difficulty to data comparison and, in some cases, inducing precision and repeatability errors. For this reason, the main aim of this study is to develop the methods and tools to achieve a deep knowledge of those floating systems and obtain capabilities to optimize their operationally thresholds. This abstract presents a methodology and an instrumental system applicable both in field and laboratory: SRECMOCOS Project (Small scale REal-time Caisson MOnitoring and COntrol System). SRECMOCOS compiles three modules. For the monitoring and control of the structure it has been developed a synchronized open and modular microcontroller-based electronic system that comprises sensors, to monitor agents and reactions, and actuators to perform pertinent actions after processing the sensors' data. A secondary objective has been to design and implement a global scaled simulator (1:22), at the 3D basin of The Harbour Research Lab at Technical University of Madrid, in which climatic agents and those derived from the rig/maneuvering setup and the structural design were included. The particular case of Campamento's drydock, in Algeciras Bay (Spain), has been used to apply and validate the methodology. SRECMOCOS Project conjugates control, monitoring and wireless communication systems in a real time basis, offering the possibility to register and simulate all the parameters involved in port operations. This approach offers a step forward into a monitoring strategy to be included in monitoring

  14. Tunable single and dual mode operation of an external cavity quantum-dot injection laser

    International Nuclear Information System (INIS)

    Biebersdorf, A; Lingk, C; De Giorgi, M; Feldmann, J; Sacher, J; Arzberger, M; Ulbrich, C; Boehm, G; Amann, M-C; Abstreiter, G

    2003-01-01

    We investigate quantum-dot (QD) lasers in an external cavity using Littrow and Littman configurations. Here, we report on a continuously tunable QD laser with a broad tuning range from 1047 to 1130 nm with high stability and efficient side mode suppression. The full-width at half-maximum of the laser line is 0.85 nm determined mainly by the quality of the external grating. This laser can be operated in a dual-mode modus, where the mode-spacing can be tuned continuously between 1.1 and 34 nm. Simultaneous emission of the two laser modes is shown by sum frequency generation experiments

  15. The Study of Operation Modes and Control Strategies of a Multidirectional MC for Battery Based System

    Directory of Open Access Journals (Sweden)

    Saman Toosi

    2015-01-01

    Full Text Available To enhance the performance of stand-alone battery based system and to achieve the continuous power transmission, the behavior of multidirectional matrix converter (MDMC has been analyzed in different operation modes. A systematic method interfacing a renewable source, a storage battery, and a load is proposed for a stand-alone battery based power system (SABBPS to utilize the MDMC as PWM converter, inverter, or PWM converter and inverter in different operation modes. In this study, the Extended Direct Duty Pulse Width Modulation (EDDPWM technique has been applied to control the power flow path between the renewable source, load, and the battery. Corresponding to generator voltage, input frequency, and loads demands, several operating states and control strategies are possible. Therefore, the boundaries and distribution of operation modes are discussed and illustrated to improve the system performance. The mathematical equation of the EDDPWM under different operation modes has been derived to achieve the maximum voltage ratio in each mode. The theoretical and modulation concepts presented have been verified in simulation using MATLAB and experimental testing. Moreover, the THD, ripple, and power flow direction have been analyzed for output current to investigate the behavior of system in each operation mode.

  16. Transverse mode instabilities in burst operation of high-power fiber laser systems

    Science.gov (United States)

    Jauregui, Cesar; Stihler, Christoph; Tünnermann, Andreas; Limpert, Jens

    2018-02-01

    We propose, to the best of our knowledge, the first mitigation strategy for TMI based on controlling the phase shift between the thermally-induced index grating and the modal intensity pattern. In particular, in this work we present a study of transverse mode instabilities in burst operation in a high-power fiber laser system. It is shown that, with a careful choice of the parameters, this operation regime can potentially lead to the mitigation of TMI by forcing an energy transfer from the higher-order-modes into the fundamental mode during the burst.

  17. Single mode operation of a hybrid optically pumped D2O far infrared laser

    International Nuclear Information System (INIS)

    Yuan, D.C.; Siegrist, M.R.

    1990-04-01

    We have achieved single mode operation in a hybrid optically pumped D 2 O far infrared laser. The active volume of the resonator was divided into two sections separated by a thin plastic foil. The larger section served as the main gain medium and the shorter section as mode selective element. The vapor pressure in the smaller volume was either very low or alternatively about 3 times higher than the pressure in the main part. In both cases single mode operation was achieved without any reduction of the total output energy. (author) 13 refs., 7 figs

  18. Operation Modes and Control Schemes for Internet-Based Teleoperation System with Time Delay

    Institute of Scientific and Technical Information of China (English)

    曾庆军; 宋爱国

    2003-01-01

    Teleoperation system plays an important role in executing task under hazard environment. As the computer networks such as the Internet are being used as the communication channel of teleoperation system, varying time delay causes the overall system unstable and reduces the performance of transparency. This paper proposed twelve operation modes with different control schemes for teleoperation on the Internet with time delay. And an optimal operation mode with control scheme was specified for teleoperation with time delay, based on the tradeoff between passivity and transparency properties. It experimentally confirmed the validity of the proposed optimal mode and control scheme by using a simple one DOF master-slave manipulator system.

  19. Innovative operating modes and techniques for the spaceborne imaging radar-C instrument

    Science.gov (United States)

    Huneycutt, Bryan L.

    1990-01-01

    The operation of the spaceborne imaging radar-C (SIR-C) is discussed. The SIR-C instrument has been designed to obtain simultaneous multifrequency and simultaneous multipolarization radar images from a low earth orbit. It is a multiparameter imaging radar which will be flown during at least two different seasons. The instrument has been designed to operate in innovative modes such as the squint alignment mode, the extended aperture mode, the scansar mode, and the interferometry mode. The instrument has been designed to demonstrate innovative engineering techniques such as beam nulling for echo tracking, pulse-repetition frquency hopping for Doppler centroid tracking, generating the frequency step chirp for radar parameter flexibility, block floating point quantizing for data rate compression, and elevation beamwidth broadening for increasing the swath illumination.

  20. Online channel operation mode: Game theoretical analysis from the supply chain power structure

    Directory of Open Access Journals (Sweden)

    Song Huang

    2015-11-01

    Full Text Available Purpose: Dual-channels have been widely used in practice, and the pricing decisions and the online channel operation mode choice have been the core problems in dual-channel supply chain management. This paper focuses on the online channel operation mode choice from the supply chain power structures based on game theoretical analysis. Design/methodology/approach: This paper utilizes three kinds of game theoretical models to analyze the impact of supply chain power structures on the optimal pricing and online channel operation mode choice. Findings: Results derived in this paper indicate that when the self-price elasticity is large, the power structures have no direct impact on the decisions. However, when the self-price elasticity is small and customers’ preference for the online channel is low, then in the MS market, it is better for the retailer to operate the online channel, while in the RS market or in the VN market, it is better for the manufacturer to operate the online channel. Research limitations/implications: In this paper, we do not consider stochastic demand and asymmetric information, which may not well suit the reality. Originality/value: This paper provides a different perspective to analyze the impact of supply chain power structures on the pricing decisions and online channel operation mode choice. The comparison of these two online channel operation modes in this paper is also a unique point.

  1. Analysis of a large-break LOCA at lower operational modes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, H.Y.; Jun, H.Y.; Lee, K. [Korea Electric Power Corporation, Taejon (Korea)

    2000-10-01

    To improve Technical Specifications and Emergency Operating Guidelines (EOGs) applicable at lower operational modes it is required to perform the safety analysis reflecting the operational characteristics in those modes. Because the component availability and system configurations at lower modes are different from those of power mode, the plant safety at lower modes should be confirmed through independent analyses. In the present study, a large-break loss-of-coolant accident is analyzed to evaluate the containment pressure and temperature control function for the preparation of EOGs applicable at lower modes. To reach the required shutdown condition, the plant cool-down is controlled by the secondary steam flow and auxiliary feedwater. The mass and energy releases from primary system are obtained from RELAP5/MOD3.1 calculation and the containment pressure and temperature are evaluated with CONTEMPT-LT code. The reference plant is Korean Next Generation Reactor having 4,000 MW thermal power. Two cases of cold leg LOCA initiated at Mode 3 with and without SIT operation are calculated. At the given plant conditions, all safety injection pumps are still available. The calculation at the condition of maximum mass and energy release shows that the containment pressure and temperature can be controlled within acceptable criteria, which means the operations of 2 or 4 fan coolers are the possible success paths to achieve the containment P/T control safety function. The peak cladding temperature with minimum safety injection flow does not show remarkable excursion, which implies the lower mode LOCA at Mode 3 can be bounded by the results obtained at full power from the viewpoint of ECCS performance. (author)

  2. Thermal characterization of phacoemulsification probes operated in axial and torsional modes.

    Science.gov (United States)

    Zacharias, Jaime

    2015-01-01

    To analyze temperature increases and identify potential sources of heat generated when sleeved and sleeveless phacoemulsification probes were operated in axial and torsional modes using the Infiniti Vision System with the Ozil torsional handpiece. Phacodynamics Laboratory, Pasteur Ophthalmic Clinic, Santiago, Chile. Experimental study. Two computer-controlled thermal transfer systems were developed to evaluate the contribution of internal metal stress and tip-to-sleeve friction on heat generation during phacoemulsification using axial and torsional ultrasound modalities. Both systems incorporated infrared thermal imaging and used a black-body film to accurately capture temperature measurements. Axial mode was consistently associated with greater temperature increases than torsional mode whether tips were operated with or without sleeves. In tests involving bare tips, axial mode and torsional mode peaked at 51.7°C and 34.2°C, respectively. In an example using sleeved tips in which a 30.0 g load was applied for 1 second, temperatures for axial mode reached 45°C and for torsional mode, 38°C. Friction between the sleeved probe and the incisional wall contributed more significantly to the temperature increase than internal metal stress regardless of the mode used. In all experiments, the temperature increase observed with axial mode was greater than that observed with torsional mode, even when conditions such as power or amplitude and flow rate were varied. Tip-to-sleeve friction was a more dominant source of phaco probe heating than internal metal stress. The temperature increase due to internal metal stress was greater with axial mode than with torsional mode. Dr. Zacharias received research funding from Alcon Laboratories, Inc., to conduct this study. He has no financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  3. Assessment of body mapping sportswear using a manikin operated in constant temperature mode and thermoregulatory model control mode

    Science.gov (United States)

    Wang, Faming; Del Ferraro, Simona; Molinaro, Vincenzo; Morrissey, Matthew; Rossi, René

    2014-09-01

    Regional sweating patterns and body surface temperature differences exist between genders. Traditional sportswear made from one material and/or one fabric structure has a limited ability to provide athletes sufficient local wear comfort. Body mapping sportswear consists of one piece of multiple knit structure fabric or of different fabric pieces that may provide athletes better wear comfort. In this study, the `modular' body mapping sportswear was designed and subsequently assessed on a `Newton' type sweating manikin that operated in both constant temperature mode and thermophysiological model control mode. The performance of the modular body mapping sportswear kit and commercial products were also compared. The results demonstrated that such a modular body mapping sportswear kit can meet multiple wear/thermal comfort requirements in various environmental conditions. All body mapping clothing (BMC) presented limited global thermophysiological benefits for the wearers. Nevertheless, BMC showed evident improvements in adjusting local body heat exchanges and local thermal sensations.

  4. Two-Dimensional Simulation of Mass Transfer in Unitized Regenerative Fuel Cells under Operation Mode Switching

    Directory of Open Access Journals (Sweden)

    Lulu Wang

    2016-01-01

    Full Text Available A two-dimensional, single-phase, isothermal, multicomponent, transient model is built to investigate the transport phenomena in unitized regenerative fuel cells (URFCs under the condition of switching from the fuel cell (FC mode to the water electrolysis (WE mode. The model is coupled with an electrochemical reaction. The proton exchange membrane (PEM is selected as the solid electrolyte of the URFC. The work is motivated by the need to elucidate the complex mass transfer and electrochemical process under operation mode switching in order to improve the performance of PEM URFC. A set of governing equations, including conservation of mass, momentum, species, and charge, are considered. These equations are solved by the finite element method. The simulation results indicate the distributions of hydrogen, oxygen, water mass fraction, and electrolyte potential response to the transient phenomena via saltation under operation mode switching. The hydrogen mass fraction gradients are smaller than the oxygen mass fraction gradients. The average mass fractions of the reactants (oxygen and hydrogen and product (water exhibit evident differences between each layer in the steady state of the FC mode. By contrast, the average mass fractions of the reactant (water and products (oxygen and hydrogen exhibit only slight differences between each layer in the steady state of the WE mode. Under either the FC mode or the WE mode, the duration of the transient state is only approximately 0.2 s.

  5. Scaling of mode shapes from operational modal analysis using harmonic forces

    Science.gov (United States)

    Brandt, A.; Berardengo, M.; Manzoni, S.; Cigada, A.

    2017-10-01

    This paper presents a new method for scaling mode shapes obtained by means of operational modal analysis. The method is capable of scaling mode shapes on any structure, also structures with closely coupled modes, and the method can be used in the presence of ambient vibration from traffic or wind loads, etc. Harmonic excitation can be relatively easily accomplished by using general-purpose actuators, also for force levels necessary for driving large structures such as bridges and highrise buildings. The signal processing necessary for mode shape scaling by the proposed method is simple and the method can easily be implemented in most measurement systems capable of generating a sine wave output. The tests necessary to scale the modes are short compared to typical operational modal analysis test time. The proposed method is thus easy to apply and inexpensive relative to some other methods for scaling mode shapes that are available in literature. Although it is not necessary per se, we propose to excite the structure at, or close to, the eigenfrequencies of the modes to be scaled, since this provides better signal-to-noise ratio in the response sensors, thus permitting the use of smaller actuators. An extensive experimental activity on a real structure was carried out and the results reported demonstrate the feasibility and accuracy of the proposed method. Since the method utilizes harmonic excitation for the mode shape scaling, we propose to call the method OMAH.

  6. Demand and supply-based operating modes--a framework for analyzing health care service production.

    Science.gov (United States)

    Lillrank, Paul; Groop, P Johan; Malmström, Tomi J

    2010-12-01

    The structure of organizations that provide services should reflect the possibilities of and constraints on production that arise from the market segments they serve. Organizational segmentation in health care is based on urgency and severity as well as disease type, bodily function, principal method, or population subgroup. The result is conflicting priorities, goals, and performance metrics. A managerial perspective is needed to identify activities with similar requirements for integration, coordination, and control. The arguments in this article apply new reasoning to the previous literature. The method used in this article to classify health care provision distinguishes different types of health problems that share generic constraints of production. The analysis leads to seven different demand-supply combinations, each with its own operational logic. These are labeled demand and supply-based operating modes (DSO modes), and constitute the managerial building blocks of health care organizations. The modes are Prevention, Emergency, One visit, Project, Elective, Cure, and Care. As analytical categories the DSO modes can be used to understand current problems. Several operating modes in one unit create managerial problems of conflicting priorities, goals, and performance metrics. The DSO modes are constructed as managerially homogeneous categories or care platforms responding to general types of demand, and supply constraints. The DSO modes bring methods of industrial management to bear on efforts to improve health care. © 2010 Milbank Memorial Fund. Published by Wiley Periodicals Inc.

  7. Dual-Mode Operation of an Optical Lattice Clock Using Strontium and Ytterbium Atoms.

    Science.gov (United States)

    Akamatsu, Daisuke; Kobayashi, Takumi; Hisai, Yusuke; Tanabe, Takehiko; Hosaka, Kazumoto; Yasuda, Masami; Hong, Feng-Lei

    2018-06-01

    We have developed an optical lattice clock that can operate in dual modes: a strontium (Sr) clock mode and an ytterbium (Yb) clock mode. Dual-mode operation of the Sr-Yb optical lattice clock is achieved by alternately cooling and trapping 87 Sr and 171 Yb atoms inside the vacuum chamber of the clock. Optical lattices for Sr and Yb atoms were arranged with horizontal and vertical configurations, respectively, resulting in a small distance of the order of between the trapped Sr and Yb atoms. The 1 S 0 - 3 P 0 clock transitions in the trapped atoms were interrogated in turn and the clock lasers were stabilized to the transitions. We demonstrated the frequency ratio measurement of the Sr and Yb clock transitions by using the dual-mode operation of the Sr-Yb optical lattice clock. The dual-mode operation can reduce the uncertainty of the blackbody radiation shift in the frequency ratio measurement, because both Sr and Yb atoms share the same blackbody radiation.

  8. Qualification of a laser cutting process for nuclear dismantling operations AREVA NC BU Valorisation - CEA/DPAD - IRSN/DSU/SERAC

    International Nuclear Information System (INIS)

    2008-01-01

    A major decommissioning project is under way on the Marcoule French Atomic Site (CEA) at the UP1 reprocessing plant where AREVA plays the role of prime contractor. Due to severe radiological levels on certain cells, these require remote operations. The cutting tools commonly used today are mainly mechanical such as grinders, saws and hydraulic shears. Nowadays, the feed-back shows that the implementation of these mechanical techniques: *?Is the main factor of mechanical failures of the remote arms. *?Requires a lot of spare parts (saw blades, discs...) The future cutting operations to be done in the UP1 reprocessing plant needs to be more industrial and productive. That is why CEA and AREVA NC are evaluating a new cutting process based on a laser set up on a remote arm. The laser cutting is already widely used in none nuclear environment and the goal is to evaluate if this thermal process may be used in nuclear installations with existing remote control arms. (authors)

  9. Qualification of a laser cutting process for nuclear dismantling operations AREVA NC BU Valorisation - CEA/DPAD - IRSN/DSU/SERAC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    A major decommissioning project is under way on the Marcoule French Atomic Site (CEA) at the UP1 reprocessing plant where AREVA plays the role of prime contractor. Due to severe radiological levels on certain cells, these require remote operations. The cutting tools commonly used today are mainly mechanical such as grinders, saws and hydraulic shears. Nowadays, the feed-back shows that the implementation of these mechanical techniques: *?Is the main factor of mechanical failures of the remote arms. *?Requires a lot of spare parts (saw blades, discs...) The future cutting operations to be done in the UP1 reprocessing plant needs to be more industrial and productive. That is why CEA and AREVA NC are evaluating a new cutting process based on a laser set up on a remote arm. The laser cutting is already widely used in none nuclear environment and the goal is to evaluate if this thermal process may be used in nuclear installations with existing remote control arms. (authors)

  10. Operational range and transport barrier of the H-mode in the stellarator W7-AS

    International Nuclear Information System (INIS)

    Hirsch, M.; Amadeo, P.; Anton, M.; Baldzuhn, J.; Brakel, R.; Bleuel, J.; Fiedler, S.; Geist, T.; Grigull, P.; Hartfuss, H.J.; Jaenicke, R.; Kick, M.; Kisslinger, J.; Koponen, J.; Wagner, F.; Weller, A.; Wobig, H.; Zoletnik, S.; Holzhauer, E.

    1998-01-01

    In W7-AS the H-mode is characterized by an edge transport barrier localized in the first 3-4 cm inside the separatrix. In the ELMy H-mode preceding the quiescent state ELMs appear as a sudden breakdown of the edge transport barrier in coincidence with bursts of fluctuations. Between ELMs fluctuations are identical to those of the quiescent H-mode. The operational range of the quiescent H-mode is determined by narrow windows of the edge rotational transform and a threshold edge electron density. In contrast, ELM-like events are observed for a variety of plasma conditions by far exceeding the narrow operational windows for the quiescent state. (author)

  11. Performance comparison for modes of operation and suppression cases of the clover detector

    International Nuclear Information System (INIS)

    Kshetri, R

    2014-01-01

    Peak-to-total ratios have been extracted for a segmented clover detector for various modes of operation and suppression cases. Based on absorption and scattering of gamma-rays, a formalism has been presented for quantifying the advantages of using addback mode and active suppression. Further investigations have been performed to find if the reduction of background counts is caused more by active suppression or by addback process

  12. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode

    OpenAIRE

    Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.

    2010-01-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma def...

  13. Methods on TLD management be applicable in nuclear power plantsunder the multi-reactor operational mode

    International Nuclear Information System (INIS)

    Luo Huiyong; Wen Qinghua; Li Ruirong; Yu Enjian

    2006-01-01

    This paper discusses the methods on management of TLD dosimeters adopted in DNMC and other NPPs, analyzes and evaluates their both defects and advantages. Facing the coming of the multi-reactor operational mode applied in NPPs, a new method intelligent management mode is put forward, this optimized method not only assures the accuracy of TLD's measurement but also reduces the cost of production and improves the efficiency of management greatly. (authors)

  14. Analysis of Sleep-Mode Downlink Scheduling Operations in EPON Systems

    OpenAIRE

    Yan, Ying; Dittmann, Lars

    2011-01-01

    Energy management strategy has been considered as an important component in the future Ethernet Passive Optical Networks (EPONs). In this paper, a sleeping mode operation is studied, and a downlink packet scheduling scheme is analyzed to preserve energy consumption and maintain the required QoS. This paper proposes a novel sleep-mode downlink packet scheduling scheme in order to enhance the sleep control function. Simulation results confirm that the proposed approach offers effective power ma...

  15. Advances towards QH-mode viability for ELM-stable operation in ITER

    International Nuclear Information System (INIS)

    Garofalo, A.M.; Burrell, K.H.; DeBoo, J.C.; Schaffer, M.J.; Snyder, P.B.; Solomon, W.M.; Park, J.-K.; Lanctot, M.J.; Reimerdes, H.; McKee, G.R.; Schmitz, L.

    2011-01-01

    The application of static, non-axisymmetric, nonresonant magnetic fields (NRMFs) to high beta DIII-D plasmas has allowed sustained operation with a quiescent H-mode (QH-mode) edge and both toroidal rotation and neutral beam injected torque near zero. Previous studies have shown that QH-mode operation can be accessed only if sufficient radial shear in the plasma flow is produced near the plasma edge. In past experiments, this flow shear was produced using neutral beam injection (NBI) to provide toroidal torque. In recent experiments, this torque was nearly completely replaced by the torque from applied NRMFs. The application of the NRMFs does not degrade the global energy confinement of the plasma. Conversely, the experiments show that the energy confinement quality increases with lower plasma rotation. Furthermore, the NRMF torque increases plasma resilience to locked modes at low rotation. These results open a path towards QH-mode utilization as an edge-localized mode (ELM)-stable H-mode in the self-heated burning plasma scenario, where toroidal momentum input from NBI may be small or absent.

  16. The periodically pulsed mode of operation of magnet systems in particle accelerators

    International Nuclear Information System (INIS)

    Stange, G.

    1980-01-01

    Since in many applications in particle accelerator technology the beam duty factor, defined by the ratio of beam pulse length to the pulse to pulse period, is very small- typically in the order of 10 - 3 to 10 - 9 - it is interesting to operate the beam optical magnetic system in the periodically pulsed mode as well. Thus, by reducing the average Ohmic losses, it is possible to save energy and material. The pulsed mode of operation of magnet systems is especially adapted to those of linear accelerators and their beam transport systems, since linear accelerators are exclusively operated in this mode. But it is equally suitable for transport systems between cyclic accelerators and large storage rings as they are under development at present. (orig./WL) [de

  17. MATHEMATICAL AND EXPERIMENTAL MODELING OF CENTRIFUGAL TURBOMACHINES’ OPERATING MODES WITH A COAXIAL ARRANGEMENT OF IMPELLERS

    Directory of Open Access Journals (Sweden)

    S. V. Podbolotov

    2018-03-01

    Full Text Available The relevance of this work is conditioned by the possibility of expanding the range of efficient operation of the turbine by changing the flow pattern of the fluid flow from stage to stage. The purpose of the work is to establish rational modes of operation of turbo machines with coaxially mounted impellers. Research methodology: in this work, we used a systematic approach, which includes the analysis of the results of mathematical modeling and experimental studies. Results. We carried out the analysis of the influence of operating modes on the pressure developed by the turbine. These operating modes include directions of rotation of impellers and the value of their circumferential speeds. The study analyzed the two options of installation: the rotation of the wheels in one direction and the rotation of the wheels in the opposite direction. The theoretical studies were based on a well-known Euler theory under certain assumptions: the cross section averaged for all flow settings; the motion of impellers was made one-dimensional and axisymmetric; the impellers have an infinite number of infinitely thin blades; the flow of fluid does not have viscosity, and the influence of friction forces is absent. The experimental aerodynamic characteristics of the centrifugal turbo machine with coaxial arrangement of driving wheels were obtained on an especially designed aerodynamic stand. Pressure-flow characteristics obtained theoretically and experimentally are presented. Conclusion. The use of coaxial impellers contributes to developing pressure and allows you to extend the range of efficient operation of centrifugal turbo machines. The most rational mode of operation of coaxially mounted impellers is the counter rotation mode. The increase of pressure developed by the Turbo machinery at work in this mode is proven theoretically and confirmed experimentally. Sufficient convergence of mathematical and experimental studies suggests the reliability of the

  18. Quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields

    International Nuclear Information System (INIS)

    Burrell, K.H.; Garofalo, A.M.; Osborne, T.H.; Snyder, P.B.; Solomon, W.M.; Park, J.-K.; Fenstermacher, M.E.; Orlov, D.M.

    2013-01-01

    Quiescent H-mode (QH-mode) sustained by magnetic torque from non-axisymmetric magnetic fields is a promising operating mode for future burning plasmas including ITER. Using magnetic torque from n = 3 fields to replace counter-I p torque from neutral beam injection, we have achieved long duration, counter-rotating QH-mode operation with neutral beam injection (NBI) torque ranging continuously from counter-I p up to co-I p values of about 1 N m. This co-I p torque is about 3 times the scaled torque that ITER will have. This range also includes operation at zero net NBI torque, applicable to rf wave heated plasmas. These n = 3 fields have been created using coils either inside or, most recently, outside the toroidal coils. Experiments utilized an ITER-relevant lower single-null plasma shape and were done with ITER-relevant values ν ped * ∼0.08, β T ped ∼ 1%$ and β N = 2. Discharges have confinement quality H 98y2 = 1.3, exceeding the value required for ITER. Initial work with low q 95 = 3.4 QH-mode plasmas transiently reached fusion gain values of G = β N H 89 /q 95 2 =0.4, which is the desired value for ITER; the limits on G have not yet been established. This paper also includes the most recent results on QH-mode plasmas run without n = 3 fields and with co-I p NBI; these shots exhibit co-I p plasma rotation and require NBI torque ⩾2 N m. The QH-mode work to date has made significant contact with theory. The importance of edge rotational shear is consistent with peeling–ballooning mode theory. We have seen qualitative and quantitative agreement with the predicted torque from neoclassical toroidal viscosity. (paper)

  19. Stability of the superconductive operating mode in high current-density devices

    International Nuclear Information System (INIS)

    Wipf, S.L.

    1979-01-01

    The superconductive operating mode represents a thermal equilibrium that can tolerate a certain amount of disturbance before it is lost. The basin of attraction (BOA), in many ways equivalent to a potential well, is a measure of the size of disturbance needed to lift the device from the superconductive into a resistive operating mode. The BOA for a simple geometry is calculated and discussed. Experimental results are reported, showing how the concept is used to gain information on the disturbances occurring in a superconducting device

  20. The experimental studies of operating modes of a diesel-generator set at variable speed

    Science.gov (United States)

    Obukhov, S. G.; Plotnikov, I. A.; Surkov, M. A.; Sumarokova, L. P.

    2017-02-01

    A diesel generator set working at variable speed to save fuel is studied. The results of experimental studies of the operating modes of an autonomous diesel generator set are presented. Areas for regulating operating modes are determined. It is demonstrated that the transfer of the diesel generator set to variable speed of the diesel engine makes it possible to improve the energy efficiency of the autonomous generator source, as well as the environmental and ergonomic performance of the equipment as compared with general industrial analogues.

  1. Guidance system operations plan for manned CM earth orbital missions using program SKYLARK 1. Section 4: Operational modes

    Science.gov (United States)

    Dunbar, J. C.

    1972-01-01

    The operational modes for the guidance system operations plan for Program SKYLARK 1 are presented. The procedures control the guidance and navigation system interfaces with the flight crew and the mission control center. The guidance operational concept is designed to comprise a set of manually initiated programs and functions which may be arranged by the flight crew to implement a large class of flight plans. This concept will permit both a late flight plan definition and a capability for real time flight plan changes.

  2. DC motor operation controlled from a DC/DC power converter in pulse mode with low duty cycle

    OpenAIRE

    Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana

    2016-01-01

    In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.

  3. Energy-efficient operation of a booster RF system for Taiwan light source operated in top-up mode

    International Nuclear Information System (INIS)

    Yeh, Meng-Shu; Wang, Chaoen; Chang, Lung-Hai; Chung, Fu-Tsai; Yu, Tsung-Chi; Lin, Ming-Chyuan; Chen, Ling-Jhen; Yang, Tz-Te; Chang, Mei-Hsia; Lin, Yu-Han; Tsai, Ming-Hsun; Lo, Chih-Hung; Liu, Zong-Kai

    2015-01-01

    Contemporary light sources operate in a top-up mode to maintain their photon intensity quasi-constant so as to improve significantly the thermal stability of the photon beam and to maximize ultimately the average photon flux at a designed maximum operational beam current. Operating in a top-up mode requires frequent beam injection from the synchrotron booster to the storage ring of the light source, but the injection intervals occupy only a tiny portion of the operational time of the integrated machine. To maintain a high operational reliability, the booster RF system practically operates necessarily under injection conditions around the clock and consumes full electric power whether during top-up injection or not. How to decrease the power consumption of the booster RF system during its stand-by time but not to sacrifice the reliability and availability of the RF system is obviously of fundamental interest for routine operation of the light source in a top-up mode. Here, an energy-efficient operation of a booster RF system adaptive to top-up operation of a light source is proposed that has been developed, realized and integrated into the booster RF system of the Taiwan Light Source (TLS), and routinely operated since the end of year 2008. The klystron cathode current and RF gap voltage of the booster's accelerating RF cavity are both periodically modulated to adapt the injection rhythm during top-up operation, which results in decreased consumption of electric power of the booster RF system by more than 78%. The impact on the reliability and availability of the booster RF system has been carefully monitored during the past five operational years, delivering more than 5000 h scheduled user beam time per year. The booster RF system retains its excellent reliability and availability as previously. Neither a decrease of the service time nor an induced reliability issue from the klystron or any high-power high-voltage component of the transmitter has been

  4. Controlling the mode of operation of organic transistors through side-chain engineering

    KAUST Repository

    Giovannitti, Alexander

    2016-10-11

    Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors.

  5. Controlling the mode of operation of organic transistors through side-chain engineering

    Science.gov (United States)

    Giovannitti, Alexander; Sbircea, Dan-Tiberiu; Inal, Sahika; Nielsen, Christian B.; Bandiello, Enrico; Hanifi, David A.; Sessolo, Michele; Malliaras, George G.; McCulloch, Iain; Rivnay, Jonathan

    2016-01-01

    Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors. PMID:27790983

  6. Density fluctuation measurements via reflectometry on DIII-D during L- and H-mode operation

    International Nuclear Information System (INIS)

    Doyle, E.J.; Lehecka, T.; Luhmann, N.C. Jr.; Peebles, W.A.; Philipona, R.

    1990-01-01

    The unique ability of reflectometers to provide radial density fluctuation measurements with high spatial resolution (of the order of ≤ centimeters, is ideally suited to the study of the edge plasma modifications associated with H-mode operation. Consequently, attention has been focused on the study of these phenomena since an improved understanding of the physics of H-mode plasmas is essential if a predictive capability for machine performance is to be developed. In addition, DIII-D is ideally suited for such studies since it is a major device noted for its robust H-mode operation and excellent basic plasma profile diagnostic information. The reflectometer system normally used for fluctuation studies is an O-mode, homodyne, system utilizing 7 discrete channels spanning 15-75 GHz, with corresponding critical densities of 2.8x10 18 to 7x10 19 m -3 . The Gunn diode sources in this system are only narrowly tunable in frequency, so the critical densities are essentially fixed. An X-mode system, utilizing a frequency tunable BWO source, has also been used to obtain fluctuation data, and in particular, to 'fill in the gaps' between the discrete O-mode channels. (author) 12 refs., 5 figs

  7. Flight Simulator Evaluation of Enhanced Propulsion Control Modes for Emergency Operation

    Science.gov (United States)

    Litt, Jonathan, S; Sowers, T.; Owen, A., Karl; Fulton, Christopher, E.; Chicatelli, Amy, K.

    2012-01-01

    This paper describes piloted evaluation of enhanced propulsion control modes for emergency operation of aircraft. Fast Response and Overthrust modes were implemented to assess their ability to help avoid or mitigate potentially catastrophic situations, both on the ground and in flight. Tests were conducted to determine the reduction in takeoff distance achievable using the Overthrust mode. Also, improvements in Dutch roll damping, enabled by using yaw rate feedback to the engines to replace the function of a stuck rudder, were investigated. Finally, pilot workload and ability to handle the impaired aircraft on approach and landing were studied. The results showed that improvement in all aspects is possible with these enhanced propulsion control modes, but the way in which they are initiated and incorporated is important for pilot comfort and perceived benefit.

  8. The optimization of nuclear power plants operation modes in emergency situations

    Science.gov (United States)

    Zagrebayev, A. M.; Trifonenkov, A. V.; Ramazanov, R. N.

    2018-01-01

    An emergency situations resulting in the necessity for temporary reactor trip may occur at the nuclear power plant while normal operating mode. The paper deals with some of the operation c aspects of nuclear power plant operation in emergency situations and during threatened period. The xenon poisoning causes limitations on the variety of statements of the problem of calculating characteristics of a set of optimal reactor power off controls. The article show a possibility and feasibility of new sets of optimization tasks for the operation of nuclear power plants under conditions of xenon poisoning in emergency circumstances.

  9. Study of the zero modes of the Faddeev–Popov operator in the maximal Abelian gauge

    International Nuclear Information System (INIS)

    Capri, M.A.L.; Guimaraes, M.S.; Lemes, V.E.R.; Sorella, S.P.; Tedesco, D.G.

    2014-01-01

    A study of the zero modes of the Faddeev–Popov operator in the maximal Abelian gauge is presented in the case of the gauge group SU(2) and for different Euclidean space–time dimensions. Explicit examples of classes of normalizable zero modes and corresponding gauge field configurations are constructed by taking into account two boundary conditions, namely: (i) the finite Euclidean Yang–Mills action, (ii) the finite Hilbert norm. -- Highlights: •We study the zero modes of the Faddeev–Popov operator in the maximal Abelian gauge. •For d=2 we obtain solutions with finite action but not finite Hilbert norm. •For d=3,4 we obtain solutions with finite action and finite Hilbert norm. •These results can be compared with those previously obtained in the Landau gauge

  10. Two-coordinate mini drift chamber operating in a self-quenching streamer mode

    International Nuclear Information System (INIS)

    Chernenko, S.P.; Smykov, L.P.; Zanevskij, Yu.V.

    1993-01-01

    Two-coordinate mini drift chambers operating in a self-quenching streamer mode have been developed. The tests have demonstrated these chambers to possess an extended counting plateau, a high operating stability and a high uniformity of efficiency over detecting area. The space resolution along anode wires is not worse than 250μm; the expected space resolution for the second coordinate is about 100 μm

  11. Simulation of operation modes of isochronous cyclotron by a new interactive method

    International Nuclear Information System (INIS)

    Taraszkiewicz, R.; Talach, M.; Sulikowski, J.; Doruch, H.; Norys, T.; Sroka, A.; Kiyan, I.N.; )

    2007-01-01

    Operation mode simulation methods are based on selection of trim coil currents in the isochronous cyclotron for formation of the required magnetic field at a certain level of the main coil current. The traditional current selection method is based on finding a solution for all trim coils simultaneously. After setting the calculated operation mode, it is usually necessary to perform a control measurement of the magnetic field map and to repeat the calculation for a more accurate solution. The new current selection method is based on successively finding solutions for each particular trim coil. The trim coils are taken one by one in reverse order from the edge to the center of the isochronous cyclotron. The new operation mode simulation method is based on the new current selection method. The new method, as against the traditional one, includes iterative calculation of the kinetic energy at the extraction radius. A series of experiments on proton beam formation within the range of working acceleration radii at extraction energies from 32 to 59 MeV, which were carried out at the AIC144 multipurpose isochronous cyclotron (designed mainly for the eye melanoma treatment and production of radioisotopes) at the INP PAS (Cracow), showed that the new method makes unnecessary any control measurements of magnetic fields for getting the desired operation mode, which indicates a high accuracy of the calculation. (authors)

  12. The Radiation Safety Interlock System for Top-Up Mode Operation at NSRRC

    CERN Document Server

    Chen Chien Rong; Kao, Sheau-Ping; Liu, Joseph; Sheu, Rong-Jiun; Wang, Jau-Ping

    2005-01-01

    The radiation safety interlock systems of NSRRC have been operated for more than a decade. Some modification actions have been implemented in the past to perfect the safe operation. The machine and its interlock system were originally designed to operate at the decay mode. Recently some improvement programs to make the machine injection from original decay mode to top-up mode at NSRRC has initiated. For users at experimental area the radiation dose resulted from top-up re-fill injections where safety shutters of beam-lines are opened will dominate. In addition to radiation safety action plans such as upgrading the shielding, enlarging the exclusion zones and improving the injection efficiency, the interlock system for top-up operation is the most important to make sure that injection efficiency is acceptable. To ensure the personnel radiation safety during the top-up mode, the safety interlock upgrade and action plans will be implemented. This paper will summarize the original design logic of the safety inter...

  13. Multi-Mode Operation for On-line Uninterruptible Power Supply System

    DEFF Research Database (Denmark)

    Lu, Jinghang; Savaghebi, Mehdi; Golestan, Saeed

    2018-01-01

    To enhance the robustness and disturbance rejection ability of an on-line uninterruptible power supply (UPS) system, an Internal Model Control (IMC)-based DC-link voltage regulation method is proposed in this paper. Furthermore, the multi-mode operations of the on-line UPS system are investigated...

  14. Optimal hysteretic control for a BMAP/SM/1/N queue with two operation modes

    Directory of Open Access Journals (Sweden)

    Alexander N. Dudin

    2000-01-01

    Full Text Available We consider BMAP/SM/1 type queueing system with finite buffer of size N. The system has two operation modes, which are characterized by the matrix generating function of BMAP-input, the kernel of the semi-Markovian service process, and utilization cost. An algorithm for determining the optimal hysteresis strategy is presented.

  15. Voltage Harmonic Compensation of a Microgrid Operating in Islanded and Grid-Connected Modes

    DEFF Research Database (Denmark)

    Savaghebi, Mehdi; Jalilian, Alireza; Vasquez, Juan C.

    2011-01-01

    In this paper, a method for voltage harmonic compensation in a microgrid operating in islanded and gridconnected modes is presented. Harmonic compensation is done through proper control of distributed generators (DGs) interface converters. In order to achieve proper sharing of the compensation...

  16. Operability test report for rotary mode core sampling system number 3

    International Nuclear Information System (INIS)

    Corbett, J.E.

    1996-01-01

    This report documents the successful completion of operability testing for the Rotary Mode Core Sampling (RMCS) system number-sign 3. The Report includes the test procedure (WHC-SD-WM-OTP-174), exception resolutions, data sheets, and a test report summary

  17. Multi-operational tuneable Q-switched mode-locking Er fibre laser

    Science.gov (United States)

    Qamar, F. Z.

    2018-01-01

    A wavelength-spacing tuneable, Q-switched mode-locking (QML) erbium-doped fibre laser based on non-linear polarization rotation controlled by four waveplates and a cube polarizer is proposed. A mode-locked pulse train using two quarter-wave plates and a half-wave plate (HWP) is obtained first, and then an extra HWP is inserted into the cavity to produce different operation regimes. The evolutions of temporal and spectral dynamics with different orientation angles of the extra HWP are investigated. A fully modulated stable QML pulse train is observed experimentally. This is, to the author’s best knowledge, the first experimental work reporting QML operation without adding an extra saturable absorber inside the laser cavity. Multi-wavelength pulse laser operation, multi-pulse train continuous-wave mode-locking operation and pulse-splitting operations are also reported at certain HWP angles. The observed operational dynamics are interpreted as a mutual interaction of dispersion, non-linear effect and insertion loss. This work provides a new mechanism for fabricating cheap tuneable multi-wavelength lasers with QML pulses.

  18. Definition, analysis and experimental investigation of operation modes in hydrogen-renewable-based power plants incorporating hybrid energy storage

    International Nuclear Information System (INIS)

    Valverde, L.; Pino, F.J.; Guerra, J.; Rosa, F.

    2016-01-01

    Highlights: • A conceptual analysis of operation modes in energy storage plants is presented. • Key Performance Indicators to select operation modes are provided. • The approach has been applied to a laboratory hybrid power plant. • The methodology provides guidance for the operation of hybrid power plants. - Abstract: This paper is concerned with Operating Modes in hybrid renewable energy-based power plants with hydrogen as the intermediate energy storage medium. Six operation modes are defined according to plant topology and the possibility of operating electrolyzer and fuel cell at steady-power or partial load. A methodology for the evaluation of plant performance is presented throughout this paper. The approach includes a set of simulations over a fully validated model, which are run in order to compare the proposed operation modes in various weather conditions. Conclusions are drawn from the simulation stage using a set of Key Performance Indicators defined in this paper. This analysis yields the conclusion that certain modes are more appropriate from technical and practical standpoints when they are implemented in a real plant. From the results of the simulation assessment, selected operating modes are applied to an experimental hydrogen-based pilot plant to illustrate and validate the performance of the proposed operation modes. Experimental results confirmed the simulation study, pointing out the advantages and disadvantages of each operation mode in terms of performance and equipment durability.

  19. Operating modes and practical power flow analysis of bidirectional isolated power interface for distributed power systems

    International Nuclear Information System (INIS)

    Wen, Huiqing; Su, Bin

    2016-01-01

    Highlights: • Four operating modes of Dual-Phase-Shift control for Dual Active Bridge converter are presented. • Effects of “minor parameters” such as the deadtime and power device voltage drops are analyzed. • Accurate power flow models with Dual-Phase-Shift control are developed and verified with experimental results. • Optimal operating mode is determined with respect to the efficiency improvement. • Measured efficiency of the Dual Active Bridge converter is improved up to 14%. - Abstract: Due to the intermittent nature of the renewable energy sources including photovoltaic and wind energy, the energy storage systems are essential to stabilize dc bus voltage. Considering the discharge depth of super-capacitors and energy-storage batteries, the bidirectional isolated power interface will operate for a wide range of voltage and power. This study focuses on in-depth analysis of the dual-active-bridge dc–dc converter that is controlled by the dual-phase-shift scheme to improve the conversion efficiency in distributed power system. The power flow of each operating mode with dual-phase-shift control is characterized based on a detailed analysis of the effects of “minor parameters”, including the deadtime and power device voltage drops. The complete output power plane of the dual-active-bridge converter with dual-phase-shift control is obtained and compared with experimental results. The optimal operating mode is determined according to the practical output power range and the power flow characteristics. Experimental evaluation shows the effectiveness of the proposed power flow model with dual-phase-shift control and significant efficiency improvement using the optimal mode of dual-phase-shift compared with the conventional phase shift control.

  20. Evaluating the operational risks of biomedical waste using failure mode and effects analysis.

    Science.gov (United States)

    Chen, Ying-Chu; Tsai, Pei-Yi

    2017-06-01

    The potential problems and risks of biomedical waste generation have become increasingly apparent in recent years. This study applied a failure mode and effects analysis to evaluate the operational problems and risks of biomedical waste. The microbiological contamination of biomedical waste seldom receives the attention of researchers. In this study, the biomedical waste lifecycle was divided into seven processes: Production, classification, packaging, sterilisation, weighing, storage, and transportation. Twenty main failure modes were identified in these phases and risks were assessed based on their risk priority numbers. The failure modes in the production phase accounted for the highest proportion of the risk priority number score (27.7%). In the packaging phase, the failure mode 'sharp articles not placed in solid containers' had the highest risk priority number score, mainly owing to its high severity rating. The sterilisation process is the main difference in the treatment of infectious and non-infectious biomedical waste. The failure modes in the sterilisation phase were mainly owing to human factors (mostly related to operators). This study increases the understanding of the potential problems and risks associated with biomedical waste, thereby increasing awareness of how to improve the management of biomedical waste to better protect workers, the public, and the environment.

  1. Research on Group Operation Mode of Once-through Steam Generator

    International Nuclear Information System (INIS)

    Hao, Cheng Ming; Liu, Xinkai; Peng, Min Jun; Xia, Genglei

    2011-01-01

    Integrated Pressurized Water Reactor (IPWR) owns more than one once-through steam generators (OTSGs). Flow instability may occur in secondary side of OTSG under certain conditions. Trying to avoid the occurrence of flow instability is of great important for the safe and stable operation of OTSG. Because of the fact that flow instability often occurs in certain regions, so when OTSGs operate with low load, OTSGs can be separated into several groups, which can avoid flow instability. In this paper, operational characteristics of IPWR are analyzed by RELAP5/MOD3.4 code and during the discussion of group operation, a rapid change load operation scheme using OTSG group operation mode which can be used in IPWR is proposed

  2. Research on Group Operation Mode of Once-through Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Cheng Ming; Liu, Xinkai; Peng, Min Jun; Xia, Genglei [Harbin Engineering University, Harbin (China)

    2011-08-15

    Integrated Pressurized Water Reactor (IPWR) owns more than one once-through steam generators (OTSGs). Flow instability may occur in secondary side of OTSG under certain conditions. Trying to avoid the occurrence of flow instability is of great important for the safe and stable operation of OTSG. Because of the fact that flow instability often occurs in certain regions, so when OTSGs operate with low load, OTSGs can be separated into several groups, which can avoid flow instability. In this paper, operational characteristics of IPWR are analyzed by RELAP5/MOD3.4 code and during the discussion of group operation, a rapid change load operation scheme using OTSG group operation mode which can be used in IPWR is proposed.

  3. A Frequency-Weighted Energy Operator and complementary ensemble empirical mode decomposition for bearing fault detection

    Science.gov (United States)

    Imaouchen, Yacine; Kedadouche, Mourad; Alkama, Rezak; Thomas, Marc

    2017-01-01

    Signal processing techniques for non-stationary and noisy signals have recently attracted considerable attentions. Among them, the empirical mode decomposition (EMD) which is an adaptive and efficient method for decomposing signals from high to low frequencies into intrinsic mode functions (IMFs). Ensemble EMD (EEMD) is proposed to overcome the mode mixing problem of the EMD. In the present paper, the Complementary EEMD (CEEMD) is used for bearing fault detection. As a noise-improved method, the CEEMD not only overcomes the mode mixing, but also eliminates the residual of added white noise persisting into the IMFs and enhance the calculation efficiency of the EEMD method. Afterward, a selection method is developed to choose relevant IMFs containing information about defects. Subsequently, a signal is reconstructed from the sum of relevant IMFs and a Frequency-Weighted Energy Operator is tailored to extract both the amplitude and frequency modulations from the selected IMFs. This operator outperforms the conventional energy operator and the enveloping methods, especially in the presence of strong noise and multiple vibration interferences. Furthermore, simulation and experimental results showed that the proposed method improves performances for detecting the bearing faults. The method has also high computational efficiency and is able to detect the fault at an early stage of degradation.

  4. AIR ATMOSPHERIC-PRESSURE DISCHARGERS FOR OPERATION IN HIGH-FREQUENCY SWITCHING MODE.

    Directory of Open Access Journals (Sweden)

    L.S. Yevdoshenko

    2013-10-01

    Full Text Available Operation of two designs of compact multigap dischargers has been investigated in a high-frequency switching mode. It is experimentally revealed that the rational length of single discharge gaps in the designs is 0.3 mm, and the maximum switching frequency is 27000 discharges per second under long-term stable operation of the dischargers. It is shown that in pulsed corona discharge reactors, the pulse front sharpening results in increasing the operating electric field strength by 1.3 – 1.8 times.

  5. Improving Reliability of High Power Quasi-CW Laser Diode Arrays Operating in Long Pulse Mode

    Science.gov (United States)

    Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.

    2006-01-01

    Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data of the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.

  6. Single-Phase Microgrid with Seamless Transition Capabilities between Modes of Operation

    DEFF Research Database (Denmark)

    Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

    2015-01-01

    with the secondary control loops that are used to synchronize the microgrid as a single unit to the grid. Simulation results are given that show the seamless transitions between the two modes without any disconnection times for the CC-VSIs and VC-VSIs connected to the microgrid.......Microgrids are an effective way to increase the penetration of DG into the grid. They are capable of operating either in grid-connected or in islanded mode thereby increasing the supply reliability for the end user. This paper focuses on achieving seamless transitions from islanded to grid-connected...

  7. Possibilities and testing of CPRNG in block cipher mode of operation PM-DC-LM

    Energy Technology Data Exchange (ETDEWEB)

    Zacek, Petr; Jasek, Roman; Malanik, David [Faculty of applied Informatics, Tomas Bata University in Zlin, Zlin, Czech Republic zacek@fai.utb.cz, jasek@fai.utb.cz, dmalanik@fai.utb.cz (Czech Republic)

    2016-06-08

    This paper discusses the chaotic pseudo-random number generator (CPRNG), which is used in block cipher mode of operation called PM-DC-LM. PM-DC-LM is one of possible subversions of general PM mode. In this paper is not discussed the design of PM-DC-LM, but only CPRNG as a part of it because designing is written in other papers. Possibilities, how to change or to improve CPRNG are mentioned. The final part is devoted for a little testing of CPRNG and some testing data are shown.

  8. Possibilities and testing of CPRNG in block cipher mode of operation PM-DC-LM

    Science.gov (United States)

    Zacek, Petr; Jasek, Roman; Malanik, David

    2016-06-01

    This paper discusses the chaotic pseudo-random number generator (CPRNG), which is used in block cipher mode of operation called PM-DC-LM. PM-DC-LM is one of possible subversions of general PM mode. In this paper is not discussed the design of PM-DC-LM, but only CPRNG as a part of it because designing is written in other papers. Possibilities, how to change or to improve CPRNG are mentioned. The final part is devoted for a little testing of CPRNG and some testing data are shown.

  9. Possibilities and testing of CPRNG in block cipher mode of operation PM-DC-LM

    International Nuclear Information System (INIS)

    Zacek, Petr; Jasek, Roman; Malanik, David

    2016-01-01

    This paper discusses the chaotic pseudo-random number generator (CPRNG), which is used in block cipher mode of operation called PM-DC-LM. PM-DC-LM is one of possible subversions of general PM mode. In this paper is not discussed the design of PM-DC-LM, but only CPRNG as a part of it because designing is written in other papers. Possibilities, how to change or to improve CPRNG are mentioned. The final part is devoted for a little testing of CPRNG and some testing data are shown.

  10. Characteristics of switched reluctance motor operating in continuous and discontinuous conduction mode

    Directory of Open Access Journals (Sweden)

    Ćalasan Martin P.

    2013-01-01

    Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.

  11. Water calorimetry with thermistor bridge operated in DC and AC mode: comparative results

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, A S; Laitano, R F; Petrocchi, A [Ist. Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA, Roma (Italy)

    1997-09-01

    An experimental study was carried out to find out the optimal conditions for measuring the output signal in a water calorimeter. To this end the thermistor bridge of the calorimeter was operated in AC and in DC mode, respectively. A comparative analysis of these two alternative methods was the made. In the AC mode measurement a lock-in amplifier based experimental assembly was used and compared to the more conventional system based on a high-sensitivty DC amplifier. The AC system resulted to be preferable as far as the short term and long term reproducibility is concerned. (orig.)

  12. Water calorimetry with thermistor bridge operated in DC and AC mode: comparative results

    International Nuclear Information System (INIS)

    Guerra, A.S.; Laitano, R.F.; Petrocchi, A.

    1997-01-01

    An experimental study was carried out to find out the optimal conditions for measuring the output signal in a water calorimeter. To this end the thermistor bridge of the calorimeter was operated in AC and in DC mode, respectively. A comparative analysis of these two alternative methods was the made. In the AC mode measurement a lock-in amplifier based experimental assembly was used and compared to the more conventional system based on a high-sensitivty DC amplifier. The AC system resulted to be preferable as far as the short term and long term reproducibility is concerned. (orig.)

  13. Analysis of Sleep-Mode Downlink Scheduling Operations in EPON Systems

    DEFF Research Database (Denmark)

    Yan, Ying; Dittmann, Lars

    2011-01-01

    Energy management strategy has been considered as an important component in the future Ethernet Passive Optical Networks (EPONs). In this paper, a sleeping mode operation is studied, and a downlink packet scheduling scheme is analyzed to preserve energy consumption and maintain the required Qo......S. This paper proposes a novel sleep-mode downlink packet scheduling scheme in order to enhance the sleep control function. Simulation results confirm that the proposed approach offers effective power management on the basis of the traffic conditions. The trade-off between network performances and the power...

  14. Operation modes research of liquefied natural gas storages as a part of the ground complexes equipment

    Directory of Open Access Journals (Sweden)

    N. S. Korolev

    2014-01-01

    Full Text Available The use of the Liquefied Natural Gas (LNG in the space-rocket equipment is motivated by some advantages. That is why a lot of tests and works are actively carried out now on rocket engines using liquefied natural gas.To provide the engine tests and subsequent rocket complex operation a creation of LNG storages is demanded as a part of ground processing equipment and support for their safe operation conditions.One of LNG danger factor is its low boiling temperature, and also changing the condition, density and LNG boiling temperature at storage due to evaporation of light component, namely methane. At refill of the storages having fuel remains with a new LNG portion these factors can lead to formation of the stratified macro-layers and cause a mode of the intensive mixing that is called "rollover", with almost instant evaporation of LNG big mass and sharp pressure boost, capable to result in the storage distraction with catastrophic effects.The work objectives are formulated such as a technique development for forecasting of the LNG parameters in operating storages including the rollover mode, a comparison of calculated results of the LNG parameters with the experimental data, and a definition of possible recommendations for safe operation of LNG storages as a part of the ground complexes equipment.The paper reviews 12 publications concerning the issues and proceeding processes at operation of LNG storages, including the rollover mode.To verify the reliability of process simulation results in the LNG, represented in models by the binary methane-ethane mixture the calculated values have been compared with the experimental data for a LNG storage mode in the reservoir of a ground test complex.The reliability of developed models of the heat-mass-exchange processes in stratified on density and temperature in LNG storage with emergence of conditions for the rollover mode has been verified by comparing the settlement characteristics to the published

  15. Study of Exhaust Emissions Reduction of a Diesel Fuel Operated Heater During Transient Mode of Operation

    Directory of Open Access Journals (Sweden)

    Miklánek Ľubomír

    2014-10-01

    Full Text Available Diesel fuel operated heaters (FOHs are generally used as an independent heat source for any system in which a diesel fuel and battery power is available. Based on the fact that future engines will become even more efficient and thus less waste heat will be available to heat the passenger compartment, independent heat sources will be even more necessary.

  16. Design Considerations for CMOS Current Mode Operational Amplifiers and Current Conveyors

    DEFF Research Database (Denmark)

    Bruun, Erik

    implementations of current mode opamps in CMOS technology are described. Also, current conveyor configurations with multiple outputs and flexible feedback connections from outputs to inputs are introduced. The dissertation includes several examples of circuit configurations ranging from simple class A and class......This dissertation is about CMOS current conveyors and current mode operational amplifiers (opamps). They are generic devices for continuous time signal processing in circuits and systems where signals are represented by currents.Substantial advancements are reported in the dissertation, both...... related to circuit implementations and system configurations and to an analysis of the fundamental limitations of the current mode technique.In the field of system configurations and circuit implementations different configurations of high gain current opamps are introduced and some of the first...

  17. A square-plate ultrasonic linear motor operating in two orthogonal first bending modes.

    Science.gov (United States)

    Chen, Zhijiang; Li, Xiaotian; Chen, Jianguo; Dong, Shuxiang

    2013-01-01

    A novel square-plate piezoelectric ultrasonic linear motor operated in two orthogonal first bending vibration modes (B₁) is proposed. The piezoelectric vibrator of the linear motor is simply made of a single PZT ceramic plate (sizes: 15 x 15 x 2 mm) and poled in its thickness direction. The top surface electrode of the square ceramic plate was divided into four active areas along its two diagonal lines for exciting two orthogonal B₁ modes. The achieved driving force and speed from the linear motor are 1.8 N and 230 mm/s, respectively, under one pair orthogonal voltage drive of 150 V(p-p) at the resonance frequency of 92 kHz. The proposed linear motor has advantages over conventional ultrasonic linear motors, such as relatively larger driving force, very simple working mode and structure, and low fabrication cost.

  18. Communication: Effects of thermionic-gun parameters on operating modes in ultrafast electron microscopy

    Directory of Open Access Journals (Sweden)

    Erik Kieft

    2015-09-01

    Full Text Available Ultrafast electron microscopes with thermionic guns and LaB6 sources can be operated in both the nanosecond, single-shot and femtosecond, single-electron modes. This has been demonstrated with conventional Wehnelt electrodes and absent any applied bias. Here, by conducting simulations using the General Particle Tracer code, we define the electron-gun parameter space within which various modes may be optimized. The properties of interest include electron collection efficiency, temporal and energy spreads, and effects of laser-pulse duration incident on the LaB6 source. We find that collection efficiencies can reach 100% for all modes, despite there being no bias applied to the electrode.

  19. Impurity deposition on surface probes during different operation modes at EXTRAP T1

    International Nuclear Information System (INIS)

    Gudowska, I.; Bergsaker, H.; Hellblom, G.

    1991-01-01

    Surface probes were used in the impurity control program during initial operation of the EXTRAP T1 device. The EXTRAP concept, design and operation characteristics are given elsewhere. The dimensions of the device are R/a=0.5m/0.06m. Four different modes of operation were studied: pure EXTRAP, mixed EXTRAP, RFP and ULQ. Briefly, all four are toroidal plasma discharges, with poloidal magnetic field due to the toroidal plasma current. In the ULQ case, a relatively strong external toroidal magnetic field is applied. In the RFP, and in the mixed mode, an external toroidal field is applied early in the discharge, and the plasma subsequently relaxes into a state with self-generated toroidal field. In the EXTRAP and mixed EXTRAP modes, an additional strong external octupole field is applied, breaking the poloidal symmetry. Throughout the initial period of operation of the device, the plasma performance was largely dominated by impurities, in particular fluorine, which was present due to an accidental contamination of the vessel. Probes have been exposed in wall/liner position, and the objective has been to measure erosion and deposition and try to identify which mechanisms are mainly responsible for impurity production. (author) 5 refs., 2 figs., 1 tab

  20. The revised program for measurements in intense operation mode according to AVV-IMIS

    International Nuclear Information System (INIS)

    Bieringer, J.; Wirth, E.; Buehling, A.; Mueller-Neumann, M.; Haase, G.; Heinrich, T.; Steinkopff, T.; Wiezorek, C.

    2007-01-01

    The monitoring program for measurements in intense operation mode has been revised recently by a working group at the Federal Ministry for Environment, Nature Conservation and Reactor Safety (BMU). The major issues of the revision are reported in this contribution. Measurements in intense operation must be appropriate for fast assessment of the radiological situation, for estimating the dose to the population and for decisions on countermeasures to minimize the dose. In order to meet these requirements the structure of the measurement program in intense operation mode was divided into three phases when different exposition paths are relevant: before and during dispersion of radioactive material, immediately after dispersion of radioactive material has ended and a late phase when contamination values have decreased in different environmental media. For each of these phases a special measurement program was defined that is tailored to achieve the above mentioned objectives. Minimum detectable activity concentrations were introduced similar to the measurement program in routine operation mode. They follow the intervention levels in the catalogue of countermeasures and maximum permitted values given by the European Union (EU) for food and animal feed. The minimum detectable activity concentrations were defined such that the detection of 1/10 of the intervention levels for countermeasures is ensured. (orig.)

  1. Harmonic voltage excess problem test and analysis in UHV and EHV grid particular operation mode

    Science.gov (United States)

    Lv, Zhenhua; Shi, Mingming; Fei, Juntao

    2018-02-01

    The test and analysis of the power quality of some 1000kV UHV transmission lines and 500kV EHV transmission lines is carried out. It is found that there is harmonic voltage excess problems when the power supply of the UHV and EHV voltage line is single-ended or single-loop, the problem basically disappeared after the operation mode change, different operating conditions, the harmonic current has not been greatly affected, indicating that the harmonic voltage changes mainly caused by the system harmonic impedance. With the analysis of MATLAB Simulink system model, it can be seen that there are specific harmonic voltage excess in the system under the specific operating mode, which results in serious distortion of the specific harmonic voltage. Since such phenomena are found in 500kV and 1000kV systems, it is suggested that the test evaluation work should be done under the typical mode of operation in 500kV, 1000kV Planning and construction process to prevent the occurrence of serious distortion and the regional harmonic current monitoring and suppression work should be done.

  2. A possible way for conservatism reduction at the modelling of WWER operational modes

    International Nuclear Information System (INIS)

    Shishkov, L. K.

    2010-01-01

    The paper discusses the way to ensure safety operation of the WWER by meet ing the technological Safety Criteria that are defined in the documents of the state level. That Safety Criteria are ensured by-turn by implementation of the design limits for the number of core parameters at normal operation. Verification of the Safety Criteria adherences for all design modes of NPP operation is conducted in assumption that all (if possible) core parameters that have the design limits reach these limiting values. Additionally, to take into account possible error of modeling, a reactor operates in conditions for the core parameters to not reach the limits with probability greater than 95%. This method is deliberately conservative and it may be substituted with 'probabilistic method'. Probabilistic method supposes the operational parameters are defined with accounting of the possible random deviation to ensure the probability of technological Safety Criteria to be met. (Author)

  3. Damage classification of pipelines under water flow operation using multi-mode actuated sensing technology

    International Nuclear Information System (INIS)

    Lee, Changgil; Park, Seunghee

    2011-01-01

    In a structure, several types of damage can occur, ranging from micro-cracking to corrosion or loose bolts. This makes identifying the damage difficult with a single mode of sensing. Therefore, a multi-mode actuated sensing system is proposed based on a self-sensing circuit using a piezoelectric sensor. In self-sensing-based multi-mode actuated sensing, one mode provides a wide frequency-band structural response from the self-sensed impedance measurement and the other mode provides a specific frequency-induced structural wavelet response from the self-sensed guided wave measurement. In this experimental study, a pipeline system under water flow operation was examined to verify the effectiveness and robustness of the proposed structural health monitoring approach. Different types of structural damage were inflicted artificially on the pipeline system. To classify the multiple types of structural damage, supervised learning-based statistical pattern recognition was implemented by composing a three-dimensional space using the damage indices extracted from the impedance and guided wave features as well as temperature variations. For a more systematic damage classification, several control parameters were optimized to determine an optimal decision boundary for the supervised learning-based pattern recognition. Further research issues are also discussed for real-world implementations of the proposed approach

  4. Effect of mode of operation on hydrogen production from glycerol at thermal neutral conditions: Thermodynamic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pairojpiriyakul, Thirasak; Soottitantawat, Apinan; Arpornwichanop, Amornchai; Assabumrungrat, Suttichai [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University (Thailand); Kiatkittipong, Worapon [Department of Chemical Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University (Thailand); Wiyaratn, Wisitsree [Department of Production Technology Education, Faculty of Industrial Education and Technology, King Mongkut' s University of Technology Thonburi (Thailand); Laosiripojana, Navadol [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi (Thailand); Croiset, Eric [Department of Chemical Engineering, University of Waterloo (Canada)

    2010-10-15

    Thermodynamic analysis of hydrogen production from glycerol under thermal neutral conditions is studied in this work. Heat requirement from the process can be achieved from the exothermic reaction of glycerol with oxygen in air fed to the system. Two modes of operation for air feeding are considered including (i) Single-feed mode in which air is fed in combination with water and glycerol to the reformer, and (ii) Split-feed mode in which air and part of glycerol is fed to a combustor in order to generate heat. The thermal neutral conditions are considered for two levels including Reformer and System levels. It was found that the H{sub 2} yield from both modes is not significantly different at the Reformer level. In contrast, the difference becomes more pronounced at the System level. Single-feed and Split-feed modes offer high H{sub 2} yield in low (600-900 K) and high (900-1200 K) temperature ranges, respectively. The maximum H{sub 2} yields are 5.67 (water to glycerol ratio, WGR = 12, oxygen to glycerol ratio, OGR = 0.37, T = 900 K, Split-feed mode), and 3.28 (WGR = 3, OGR = 1.40, T = 900 K, Single-feed mode), for the Reformer and System levels, respectively. The difference between H{sub 2} yields in both levels mainly arises from the huge heat demand for preheating feeds in the System level, and therefore, a higher amount of air is needed to achieve the thermal neutral condition. Split-feed mode is a favorable choice in term of H{sub 2} purity because the gas product is not diluted with N{sub 2} from the air. The use of pure O{sub 2} and afterburner products (ABP) stream were also considered at the System level. The maximum H{sub 2} yield becomes 3.75 (WGR = 5.21, OGR = 1.28, T = 900 K, Split-feed mode) at thermal neutral condition when utilizing heat from the ABP stream. Finally comparisons between the different modes and levels are addressed in terms of yield of by-products, and carbon formation. (author)

  5. ITER operational space for full plasma current H-mode operation

    Energy Technology Data Exchange (ETDEWEB)

    Mattei, M. [Assoc. Euratom-ENEA-CREATE, Seconda University di Napoli, Aversa (Italy)], E-mail: massimiliano.mattei@unirc.it; Cavinato, M.; Saibene, G.; Portone, A. [Fusion for Energy Joint Undertaking, 08019 Barcelona (Spain); Albanese, R.; Ambrosino, G. [Assoc. Euratom-ENEA-CREATE, University Napoli Federico II, Napoli (Italy); Horton, L.D. [Max Planck-Institut fur Plasmaphysik, EURATOM-Association, Garching (Germany); Kessel, C. [Princeton Plasma Physics Laboratory, Princeton University (United States); Koechl, F. [Assoc. EURATOM-OAW/ATI, Vienna (Austria); Lomas, P.J. [Euratom/UKAEA Fusion Assoc., Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Nunes, I. [Assoc. EURATOM/IST, Centro de Fusao Nuclear, Lisbon (Portugal); Parail, V. [Max Planck-Institut fur Plasmaphysik, EURATOM-Association, Garching (Germany); Sartori, R. [Fusion for Energy Joint Undertaking, 08019 Barcelona (Spain); Sips, A.C.C. [Max Planck-Institut fur Plasmaphysik, EURATOM-Association, Garching (Germany); Thomas, P.R. [Fusion for Energy Joint Undertaking, 08019 Barcelona (Spain)

    2009-06-15

    Sensitivity studies performed as part of the ITER IO design review highlighted a very stiff dependence of the maximum Q attainable on the machine parameters. In particular, in the considered range, the achievable Q scales with I{sub p}{sup 4}. As a consequence, the achievement of the ITER objective of Q = 10 requires the machine to be routinely operated at a nominal current I{sub p} of 15 MA, and at full toroidal field BT of 5.3 T. This paper analyses the capabilities of the poloidal field (PF) system (including the central solenoid) of ITER against realistic full current plasma scenarios. An exploration of the ITER operational space for the 15 and 17 MA inductive scenario is carried out. An extensive analysis includes the evaluation of margins for the closed loop shape control action. The overall results of this analysis indicate that the control of a 15 MA plasma in ITER is likely to be adequate in the range of li 0.7-0.9 whereas, for a 17 MA plasma, control capabilities are strongly reduced. The ITER operational space, provided by the reference pre-2008 PF system, was rather limited if compared to the range of parameters normally observed in present experiment. Proposals for increasing the current and field limits on PF2, PF5 and PF6, adjustment on the number of turns in some of the PF coils, changes to the divertor dome geometry, to the conductor of PF6 to Nb3Sn, moving PF6 radially and/or vertically are described and evaluated in the paper. Some of them have been included in 2008 ITER revised configuration.

  6. Passively mode-locked Nd:YVO4 laser operating at 1073 nm and 1085 nm

    Science.gov (United States)

    Waritanant, Tanant; Major, Arkady

    2018-02-01

    A passively mode-locked Nd:YVO4 laser operating at 1073 nm and 1085 nm was demonstrated with an intracavity birefringent filter as the wavelength selecting element. The average output powers achieved were 2.17 W and 2.18 W with optical-to-optical efficiency of 19.6% and 19.7%, respectively. The slope efficiencies were more than 31% at both output wavelengths. The pulse durations at the highest average output power were 10.3 ps and 8.4 ps, respectively. We believe that this is the first report of mode locking of a Nd:YVO4 laser operating at 1073 nm or 1085 nm lines.

  7. Harmonics Suppression for Single-Phase Grid-Connected Photovoltaic Systems in Different Operation Modes

    DEFF Research Database (Denmark)

    Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

    2013-01-01

    -connected PV inverters may be severely affected in different operation modes. In this paper, a detailed analysis is conducted to reveal the relationship between the harmonics level with the power factor and the current level in the PV systems. A current control solution which employs an Internal Model...... Principle (IMP) is proposed to suppress the harmonic currents injected into the grid. Experiments are carried out to verify the analysis and the performance of the proposed control method. It is demonstrated that the proposed method presents an effective solution to harmonics suppression for single......-phase grid-connected PV systems in different operation modes. Especially, it can remove higher order harmonics effectively leading to a better power quality compared to the Proportional plus Multi-Resonant Controller, and it has less computational burden....

  8. Single longitudinal mode operation of a solid-state dye laser oscillator

    CERN Document Server

    Lim, G; Kim, H S; Cha, B H; Lee, J M

    2000-01-01

    We have operated a single longitudinal mode of a solid-state dye laser oscillator in a Littman configuration. The host material of the solid-state gain medium was rhodamine dye-doped poly (methyl methacrylate). The pumping source was the second harmonic of a Nd:YAG laser with a repetition rate of 10 Hz. The measured linewidth of the laser output was about 1.5 GHz.

  9. Local and global performance of double-gap resistive plate chambers operated in avalanche mode

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Gianini, G.; Ratti, S.P.; Viola, L.; Vitulo, P.; Sergueev, S

    1999-09-21

    Two large double-gap resistive plate chambers, with 2 and 3 mm gap widths, were tested to study their response uniformity when operated in avalanche mode. The effects of mechanical tolerances and the presence of the spacers is thoroughly examined. Results on efficiency and time resolution are presented. We find that average performance and response uniformity over the whole chamber surface are fully adequate to the requirements of future collider experiments. (author)

  10. N Reactor thermal plume characterization during Pu-only mode of operation

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, R.M.; Thompson, F.L.; Whelan, G.

    1983-04-01

    Pacific Northwest Laboratories (PNL) performed field and modeling studies -from March 1982 through June 1983 to characterize the thermal plume from the N Reactor heated water outfall while the N Reactor operated in the Pu-only mode. Part 1 of this report deals with the field studies conducted to characterize the N Reactor thermal plume while in the Pu-only mode of operation. It includes a description of the study area, a description of field tasks and procedures, and data collection results and discussion. Part 2 describes the computer simulation of the thermal plume under different flow conditions and the calibration of the model used. It includes a description of the computer model and the assumptions on which it is based, a presentation of the input data used in this application, and a discussion of modeling results. Because the field studies were restricted by the NPOES permit variance to the spring months when high Columbia River flows prevail the mathematical modeling of the N Reactor thermal plume while the reactor operates in the Pu-only mode is instrumental in characterizing the plume during low Columbia River flows.

  11. Operation mode switchable charge-trap memory based on few-layer MoS2

    Science.gov (United States)

    Hou, Xiang; Yan, Xiao; Liu, Chunsen; Ding, Shijin; Zhang, David Wei; Zhou, Peng

    2018-03-01

    Ultrathin layered two-dimensional (2D) semiconductors like MoS2 and WSe2 have received a lot of attention because of their excellent electrical properties and potential applications in electronic devices. We demonstrate a charge-trap memory with two different tunable operation modes based on a few-layer MoS2 channel and an Al2O3/HfO2/Al2O3 charge storage stack. Our device shows excellent memory properties under the traditional three-terminal operation mode. More importantly, unlike conventional charge-trap devices, this device can also realize the memory performance with just two terminals (drain and source) because of the unique atomic crystal electrical characteristics. Under the two-terminal operation mode, the erase/program current ratio can reach up to 104 with a stable retention property. Our study indicates that the conventional charge-trap memory cell can also realize the memory performance without the gate terminal based on novel two dimensional materials, which is meaningful for low power consumption and high integration density applications.

  12. Dual-mode operation of 2D material-base hot electron transistors

    KAUST Repository

    Lan, Yann-Wen; Jr., Carlos M. Torres,; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

    2016-01-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  13. Dual-mode operation of 2D material-base hot electron transistors.

    Science.gov (United States)

    Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

    2016-09-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  14. Modified Adaptive Control for Region 3 Operation in the Presence of Wind Turbine Structural Modes

    Science.gov (United States)

    Frost, Susan Alane; Balas, Mark J.; Wright, Alan D.

    2010-01-01

    Many challenges exist for the operation of wind turbines in an efficient manner that is reliable and avoids component fatigue and failure. Turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, possibly causing component fatigue and failure. Wind turbine manufacturers are highly motivated to reduce component fatigue and failure that can lead to loss of revenue due to turbine down time and maintenance costs. The trend in wind turbine design is toward larger, more flexible turbines that are ideally suited to adaptive control methods due to the complexity and expense required to create accurate models of their dynamic characteristics. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed horizontal axis wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the excitation of structural modes in the wind turbine. The control objective is accomplished by collectively pitching the turbine blades. The adaptive collective pitch controller for Region 3 was compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. The adaptive controller will demonstrate the ability to regulate generator speed in Region 3, while accommodating gusts, and reducing the excitation of certain structural modes in the wind turbine.

  15. Dual-mode operation of 2D material-base hot electron transistors

    KAUST Repository

    Lan, Yann-Wen

    2016-09-01

    Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (V-CB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (V-CB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

  16. Selection of stirling engine parameter and modes of joint operation with the Topaz II

    International Nuclear Information System (INIS)

    Kirillov, E.Y.; Ogloblin, B.G.; Shalaev, A.I.

    1996-01-01

    In addition to a high-temperature thermionic conversion cycle, application of a low-temperature machine cycle, such as the Stirling engine, is being considered. To select the optimum mode for joint operation of the Topaz II system and Stirling engine, output electric parameters are obtained as a function of thermal power released in the TFE fuel cores. The hydraulic diagram used for joint operation of the Topaz II and the Stirling engine is considered. Requirements to hydraulic characteristics of the Stirling engine heat exchanges are formulated. Scope of necessary modifications to mount the Stirling Engine on the Topaz II is estimated. copyright 1996 American Institute of Physics

  17. Operation of heavily irradiated silicon detectors in non-depletion mode

    International Nuclear Information System (INIS)

    Verbitskaya, E.; Eremin, V.; Ilyashenko, I.; Li, Z.; Haerkoenen, J.; Tuovinen, E.; Luukka, P.

    2006-01-01

    The non-depletion detector operation mode has generally been disregarded as an option in high-energy physics experiments. In this paper, the non-depletion operation is examined by detailed analysis of the electric field distribution and the current pulse response of heavily irradiated silicon (Si) detectors. The previously reported model of double junction in heavily irradiated Si detector is further developed and a simulation of the current pulse response has been performed. It is shown that detectors can operate in a non-depletion mode due to the fact that the value of the electric field in a non-depleted region is high enough for efficient carrier drift. This electric field originates from the current flow through the detector and a consequent drop of the potential across high-resistivity bulk of a non-depleted region. It is anticipated that the electric field in a non-depleted region, which is still electrically neutral, increases with fluence that improves the non-depleted detector operation. Consideration of the electric field in a non-depleted region allows the explanation of the recorded double-peak current pulse shape of heavily irradiated Si detectors and definition of the requirements for the detector operational conditions. Detailed reconstruction of the electric field distribution gives new information on radiation effects in Si detectors

  18. Comparison of collision operators for drift and MHD-interchange modes in unsheared slab geometry

    International Nuclear Information System (INIS)

    Rewoldt, G.; Tang, W.M.; Hastie, R.J.

    1986-02-01

    The general procedure for the kinetic analysis of low-frequency electrostatic and electromagnetic modes in toroidal geometry is now well known. In the collisionless limit, the relevant dynamics (e.g., trapped particles, resonances, etc.) can be treated appropriately. However, with the introduction of collisional effects, it is customary, for tractability, to employ model collision operators which do not rigorously satisfy all conservation properties of more exact collision operators. Insight into the essential required features of such operators can be gained by studying models with increasing levels of completeness for a simpler, unsheared slab geometry. The results presented here for this simpler geometry can provide guidance in choosing model collision operators for toroidal-geometry kinetic calculations. 6 refs., 3 figs

  19. A novel ToF-SIMS operation mode for sub 100 nm lateral resolution: Application and performance

    International Nuclear Information System (INIS)

    Kubicek, Markus; Holzlechner, Gerald; Opitz, Alexander K.; Larisegger, Silvia; Hutter, Herbert; Fleig, Jürgen

    2014-01-01

    A novel operation mode for time of flight-secondary ion mass spectrometry (ToF-SIMS) is described for a TOF.SIMS 5 instrument with a Bi-ion gun. It features sub 100 nm lateral resolution, adjustable primary ion currents and the possibility to measure with high lateral resolution as well as high mass resolution. The adjustment and performance of the novel operation mode are described and compared to established ToF-SIMS operation modes. Several examples of application featuring novel scientific results show the capabilities of the operation mode in terms of lateral resolution, accuracy of isotope analysis of oxygen, and combination of high lateral and mass resolution. The relationship between high lateral resolution and operation of SIMS in static mode is discussed.

  20. A novel ToF-SIMS operation mode for sub 100 nm lateral resolution: Application and performance.

    Science.gov (United States)

    Kubicek, Markus; Holzlechner, Gerald; Opitz, Alexander K; Larisegger, Silvia; Hutter, Herbert; Fleig, Jürgen

    2014-01-15

    A novel operation mode for time of flight-secondary ion mass spectrometry (ToF-SIMS) is described for a TOF.SIMS 5 instrument with a Bi-ion gun. It features sub 100 nm lateral resolution, adjustable primary ion currents and the possibility to measure with high lateral resolution as well as high mass resolution. The adjustment and performance of the novel operation mode are described and compared to established ToF-SIMS operation modes. Several examples of application featuring novel scientific results show the capabilities of the operation mode in terms of lateral resolution, accuracy of isotope analysis of oxygen, and combination of high lateral and mass resolution. The relationship between high lateral resolution and operation of SIMS in static mode is discussed.

  1. Operating modes of electrochemical H-concentration probes for tritium sensors

    International Nuclear Information System (INIS)

    Juhera, E.; Colominas, S.; Abellà, J.

    2015-01-01

    Highlights: • Synthesis and chemical characterization of Sr(Ce_0_._9–Zr_0_._1)_0_._9_5Yb_0_._0_5O_3_−_α proton conductor ceramic. • Evaluation of the sensor performance at different hydrogen concentrations. • Two different operating modes of the sensors: amperometric and potentiometric. • In amperometric mode sensor sensitivity can be tuned by changing the applied voltage. - Abstract: Potentiometric hydrogen sensors using different solid-state electrolytes have been designed and tested at the Electrochemical Methods Lab at Institut Quimic de Sarria (IQS). The most promising element (Sr(Ce_0_._9–Zr_0_._1)_0_._9_5Yb_0_._0_5O_3_−_α) has been selected for this work in order to evaluate the sensor performance at different hydrogen concentrations in two different operating modes: amperometric and potentiometric. In addition, the sensor response has been evaluated at different working temperatures (500, 575 and 650 °C). The experiments performed proved that when the sensor was used in a potentiometric mode, there is a threshold hydrogen concentration that the sensor can detect depending on the working conditions; 15 mbar at 575 °C and 10 mbar 650 °C. At 500 °C the minimum working temperature of this ceramic has not been achieved, so large deviations between experimental data and theoretical calculations has been obtained. When the sensor was used in an amperometric mode the obtained currents increased as a function of the applied voltage. At a fixed potential, the higher the temperature the higher the current was. So the sensor sensitivity can be tuned by changing the applied voltage at a fixed temperature and hydrogen concentration.

  2. Operator support system for power unit control in abnormal modes of operation

    International Nuclear Information System (INIS)

    Kurka, J.

    1993-01-01

    I and C system technology, partly Soviet and partly Czechoslovakian, used on the NPP Dukovany units represents the control technology standard of late 70-ties and it becomes the weak part of the whole system. The modernization of the system, therefore, is necessary and it is already in preparation. The specification of both the scope and the depth of upgrading/replacement is being carried out within the framework of the PHARE program. The second phase of the program aimed at the final specifications of requirements on new I and C system is in progress. The output will serve as detailed specification for bid invitation for control system supplier. Parallely, the preparation of specification for WWER-440 full-scope plant simulator for operator training is in progress as well. In the case of two units with WWER-1000 MW reactors, the completion of construction of which was even threaten for a certain period of time, essential changes have taken place in the design of both the I and C systems and the reactor core. 7 figs

  3. Migration behavior of Cu and Zn in landfill with different operation modes

    International Nuclear Information System (INIS)

    Long Yuyang; Shen Dongsheng; Wang Hongtao; Lu Wenjing

    2010-01-01

    Cu and Zn were chosen to study the heavy metal migration behavior and mechanism in three simulated landfills with different operation modes, namely conventional landfill (CL), leachate directly recirculated landfill (RL) and leachate pre-treated bioreactor landfill (BL). It showed that Cu and Zn in refuse experienced periodic migration and retention gradually during decomposition, and the variation of Cu(II) and Zn(II) in leachate correspondingly reflected the releasing behavior of Cu and Zn in landfill refuse at different stabilization stages. Except for their accumulated leaching amounts, Cu(II) and Zn(II) concentrations in leachate from landfills with different operation modes had no significant difference. The accumulated leaching amounts of Cu and Zn from CL showed exponential increase, while those of RL and BL showed exponential decay. The operation of bioreactor landfill with leachate recirculation can obviously attenuate the heavy metal leaching than conventional operation. The introduction of methanogenic reactor (MR) in bioreactor landfill can further promote the immobilization of heavy metal in refuse than leachate recirculation directly.

  4. New VCSEL technology with scalability for single mode operation and densely integrated arrays

    Science.gov (United States)

    Zhao, Guowei; Demir, Abdullah; Freisem, Sabine; Zhang, Yu; Liu, Xiaohang; Deppe, Dennis G.

    2011-06-01

    Data are presented demonstrating a new lithographic vertical-cavity surface-emitting laser (VCSEL) technology, which produces simultaneous mode- and current-confinement only by lithography and epitaxial crystal growth. The devices are grown by solid source molecular beam epitaxy, and have lithographically defined sizes that vary from 3 μm to 20 μm. The lithographic process allows the devices to have high uniformity throughout the wafer and scalability to very small size. The 3 μm device shows a threshold current of 310 μA, the slope efficiency of 0.81 W/A, and the maximum output power of more than 5 mW. The 3 μm device also shows single-mode single-polarization operation without the use of surface grating, and has over 25 dB side-mode-suppression-ratio up to 1 mW of output power. The devices have low thermal resistance due to the elimination of oxide aperture. High reliability is achieved by removal of internal strain caused by the oxide, stress test shows no degradation for the 3 μm device operating at very high injection current level of 142 kA/cm2 for 1000 hours, while at this dive level commercial VCSELs fail rapidly. The lithographic VCSEL technology can lead to manufacture of reliable small size laser diode, which will have application in large area 2-D arrays and low power sensors.

  5. QUIESCENT H-MODE, AN ELM-FREE HIGH-CONFINEMENT MODE ON DIII-D WITH POTENTIAL FOR STATIONARY STATE OPERATION

    International Nuclear Information System (INIS)

    WEST, WP; BURRELL, KH; DeGRASSIE, JS; DOYLE, EJ; GREENFIELD, CM; LASNIER, CJ; SNYDER, PB; ZENG, L.

    2003-01-01

    OAK-B135 The quiescent H-mode (QH-mode) is an ELM-free and stationary state mode of operation discovered on DIII-D. This mode achieves H-mode levels of confinement and pedestal pressure while maintaining constant density and radiated power. The elimination of edge localized modes (ELMs) and their large divertor loads while maintaining good confinement and good density control is of interest to next generation tokamaks. This paper reports on the correlations found between selected parameters in a QH-mode database developed from several hundred DIII-D counter injected discharges. Time traces of key plasma parameters from a QH-mode discharge are shown. On DIII-D the negative going plasma current (a) indicates that the beam injection direction is counter to the plasma current direction, a common feature of all QH-modes. The D α time behavior (c) shows that soon after high powered beam heating (b) is applied, the discharge makes a transition to ELMing H-mode, then the ELMs disappear, indicating the start of the QH period that lasts for the remainder of the high power beam heating (3.5 s). Previously published work showing density and temperature profiles indicates that long-pulse, high-triangularity QH discharges develop an internal transport barrier in combination with the QH edge barrier. These discharges are known as quiescent, double-barrier discharges (QDB). The H-factor (d) and stored energy (c) rise then saturate at a constant level and the measured axial and minimum safety factors remain above 1.0 for the entire QH duration. During QDB operation the performance of the plasma can be very good, with β N *H 89L product reaching 7 for > 10 energy confinement times. These discharges show promise that a stationary state can be achieved

  6. QUIESCENT H-MODE, AN ELM-FREE HIGH-CONFINEMENT MODE ON DIII-D WITH POTENTIAL FOR STATIONARY STATE OPERATION

    Energy Technology Data Exchange (ETDEWEB)

    WEST,WP; BURRELL,KH; deGRASSIE,JS; DOYLE,EJ; GREENFIELD,CM; LASNIER,CJ; SNYDER,PB; ZENG,L

    2003-08-01

    OAK-B135 The quiescent H-mode (QH-mode) is an ELM-free and stationary state mode of operation discovered on DIII-D. This mode achieves H-mode levels of confinement and pedestal pressure while maintaining constant density and radiated power. The elimination of edge localized modes (ELMs) and their large divertor loads while maintaining good confinement and good density control is of interest to next generation tokamaks. This paper reports on the correlations found between selected parameters in a QH-mode database developed from several hundred DIII-D counter injected discharges. Time traces of key plasma parameters from a QH-mode discharge are shown. On DIII-D the negative going plasma current (a) indicates that the beam injection direction is counter to the plasma current direction, a common feature of all QH-modes. The D{sub {alpha}} time behavior (c) shows that soon after high powered beam heating (b) is applied, the discharge makes a transition to ELMing H-mode, then the ELMs disappear, indicating the start of the QH period that lasts for the remainder of the high power beam heating (3.5 s). Previously published work showing density and temperature profiles indicates that long-pulse, high-triangularity QH discharges develop an internal transport barrier in combination with the QH edge barrier. These discharges are known as quiescent, double-barrier discharges (QDB). The H-factor (d) and stored energy (c) rise then saturate at a constant level and the measured axial and minimum safety factors remain above 1.0 for the entire QH duration. During QDB operation the performance of the plasma can be very good, with {beta}{sub N}*H{sub 89L} product reaching 7 for > 10 energy confinement times. These discharges show promise that a stationary state can be achieved.

  7. Single mode operation in a pulsed Ti:sapphire laser oscillator with a grazing-incidence four-mirror cavity

    CERN Document Server

    Ko, D K; Binks, D J; Gloster, L A W; King, T A

    1998-01-01

    We demonstrate stable single mode operation in a pulsed Ti:sapphire laser oscillator with a novel grazing-incidence four-mirror coupled cavity. This cavity consists of a grating, a gain medium, and four mirrors and, therefore, has a four-arm interferometer configuration. Through the interferometric effect, we could suppress the adjacent modes and obtain stable single mode operation with a bandwidth of < 200 MHz. We also have developed a general analysis of the laser modes and the threshold conditions for configuration and the experimental results agree well with the theoretical predictions.

  8. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode.

    Science.gov (United States)

    Poehlmann, Flavio R; Cappelli, Mark A; Rieker, Gregory B

    2010-12-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively.

  9. A standing wave linear ultrasonic motor operating in in-plane expanding and bending modes.

    Science.gov (United States)

    Chen, Zhijiang; Li, Xiaotian; Ci, Penghong; Liu, Guoxi; Dong, Shuxiang

    2015-03-01

    A novel standing wave linear ultrasonic motor operating in in-plane expanding and bending modes was proposed in this study. The stator (or actuator) of the linear motor was made of a simple single Lead Zirconate Titanate (PZT) ceramic square plate (15 × 15 × 2 mm(3)) with a circular hole (D = 6.7 mm) in the center. The geometric parameters of the stator were computed with the finite element analysis to produce in-plane bi-mode standing wave vibration. The calculated results predicted that a driving tip attached at midpoint of one edge of the stator can produce two orthogonal, approximate straight-line trajectories, which can be used to move a slider in linear motion via frictional forces in forward or reverse direction. The investigations showed that the proposed linear motor can produce a six times higher power density than that of a previously reported square plate motor.

  10. Effect of low density H-mode operation on edge and divertor plasma parameters

    International Nuclear Information System (INIS)

    Maingi, R.; Mioduszewski, P.K.; Cuthbertson, J.W.

    1994-07-01

    We present a study of the impact of H-mode operation at low density on divertor plasma parameters on the DIII-D tokamak. The line-average density in H-mode was scanned by variation of the particle exhaust rate, using the recently installed divertor cryo-condensation pump. The maximum decrease (50%) in line-average electron density was accompanied by a factor of 2 increase in the edge electron temperature, and 10% and 20% reductions in the measured core and divertor radiated power, respectively. The measured total power to the inboard divertor target increased by a factor of 3, with the major contribution coming from a factor of 5 increase in the peak heat flux very close to the inner strike point. The measured increase in power at the inboard divertor target was approximately equal to the measured decrease in core and divertor radiation

  11. Hybrid Systems of Distributed Generation with Renewable Sources: Modeling and Analysis of Their Operational Modes in Electric Power System

    Directory of Open Access Journals (Sweden)

    A. M. Gashimov

    2013-01-01

    Full Text Available The paper considers problems pertaining to modeling and simulation of operational hybrid system modes of the distributed generation comprising conventional sources – modular diesel generators, gas-turbine power units; and renewable sources – wind and solar power plants. Operational modes of the hybrid system have been investigated under conditions of electrical connection with electric power system and in case of its isolated operation. As a consequence

  12. A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

    Science.gov (United States)

    Bai, Zhen; Zhang, Jun; Zhong, Huihuang

    2016-04-01

    An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM01. The existence of TM01 mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension of coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.

  13. A dual-mode operation overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic mode output

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Zhen; Zhang, Jun, E-mail: zhangjun@nudt.edu.cn; Zhong, Huihuang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2016-04-15

    An overmoded coaxial millimeter-wave generator with high power capacity and pure transverse electric and magnetic (TEM) mode output is designed and presented, by using a kind of coaxial slow wave structure (SWS) with large transversal dimension and small distance between inner and outer conductors. The generator works in dual-mode operation mechanism. The electron beam synchronously interacts with 7π/8 mode of quasi-TEM, at the meanwhile exchanges energy with 3π/8 mode of TM{sub 01}. The existence of TM{sub 01} mode, which is traveling wave, not only increases the beam-wave interaction efficiency but also improves the extraction efficiency. The large transversal dimension of coaxial SWS makes its power capacity higher than that of other reported millimeter-wave devices and the small distance between inner and outer conductors allows only two azimuthally symmetric modes to coexist. The converter after the SWS guarantees the mode purity of output power. Particle-in-cell simulation shows that when the diode voltage is 400 kV and beam current is 3.8 kA, the generation of microwave at 32.26 GHz with an output power of 611 MW and a conversion efficiency of 40% is obtained. The power percentage carried by TEM mode reaches 99.7% in the output power.

  14. On Convergence of Extended Dynamic Mode Decomposition to the Koopman Operator

    Science.gov (United States)

    Korda, Milan; Mezić, Igor

    2018-04-01

    Extended dynamic mode decomposition (EDMD) (Williams et al. in J Nonlinear Sci 25(6):1307-1346, 2015) is an algorithm that approximates the action of the Koopman operator on an N-dimensional subspace of the space of observables by sampling at M points in the state space. Assuming that the samples are drawn either independently or ergodically from some measure μ , it was shown in Klus et al. (J Comput Dyn 3(1):51-79, 2016) that, in the limit as M→ ∞, the EDMD operator K_{N,M} converges to K_N, where K_N is the L_2(μ )-orthogonal projection of the action of the Koopman operator on the finite-dimensional subspace of observables. We show that, as N → ∞, the operator K_N converges in the strong operator topology to the Koopman operator. This in particular implies convergence of the predictions of future values of a given observable over any finite time horizon, a fact important for practical applications such as forecasting, estimation and control. In addition, we show that accumulation points of the spectra of K_N correspond to the eigenvalues of the Koopman operator with the associated eigenfunctions converging weakly to an eigenfunction of the Koopman operator, provided that the weak limit of the eigenfunctions is nonzero. As a by-product, we propose an analytic version of the EDMD algorithm which, under some assumptions, allows one to construct K_N directly, without the use of sampling. Finally, under additional assumptions, we analyze convergence of K_{N,N} (i.e., M=N), proving convergence, along a subsequence, to weak eigenfunctions (or eigendistributions) related to the eigenmeasures of the Perron-Frobenius operator. No assumptions on the observables belonging to a finite-dimensional invariant subspace of the Koopman operator are required throughout.

  15. Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

    International Nuclear Information System (INIS)

    Parsapour, Amir; Dehkordi, Behzad Mirzaeian; Moallem, Mehdi

    2015-01-01

    In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated

  16. Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

    Energy Technology Data Exchange (ETDEWEB)

    Parsapour, Amir, E-mail: amirparsapour@gmail.com [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Dehkordi, Behzad Mirzaeian, E-mail: mirzaeian@eng.ui.ac.ir [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Moallem, Mehdi, E-mail: moallem@cc.iut.ac.ir [Department of Electrical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-03-15

    In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated.

  17. Comparative Analysis of Battery Behavior with Different Modes of Discharge for Optimal Capacity Sizing and BMS Operation

    Directory of Open Access Journals (Sweden)

    Mazhar Abbas

    2016-10-01

    Full Text Available Battery-operated systems are always concerned about the proper management and sizing of a battery. A Traditional Battery Management System (BMS only includes battery-aware task scheduling based on the discharge characteristics of a whole battery pack and do not take into account the mode of the load being served by the battery. On the other hand, an efficient and intelligent BMS should monitor the battery at a cell level and track the load with significant consideration of the load mode. Depending upon the load modes, the common modes of discharge (MOD of a battery identified so far are Constant Power Mode (CPM, Constant Current Mode (CCM and Constant Impedance Mode (CIM. This paper comparatively analyzes the discharging behavior of batteries at an individual cell level for different load modes. The difference in discharging behavior from mode to mode represents the study of the mode-dependent behavior of the battery before its deployment in some application. Based on simulation results, optimal capacity sizing and BMS operation of battery for an assumed situation in a remote microgrid has been proposed.

  18. Trickle-Charge: a New Operational Mode for PEP-II

    International Nuclear Information System (INIS)

    Kozanecki, W.; Colocho, W.S.; Decker, F.-J.; Ecklund, S.; Fisher, A.S.; Iverson, R.H.; O'Grady, C.; Seeman, J.; Sullivan, M.K.; Turner, J.L.; Weaver, M.; Wienands, U.; SLAC

    2005-01-01

    In regular top-up-and-coast operation, PEP-II average luminosity is about 70-75% of the peak luminosity due to detector ramp-down and ramp-up times plus the time it takes to top-up both beams. We recently commissioned a new operational mode where the Low Energy Ring is injected continuously without ramping down the detector. The benefits--increased luminosity lifetime and roughly half the number of top-ups per shift--were expected to give an increase in delivered luminosity of about 15% at the same peak luminosity; this was confirmed in test runs. In routine trickle operation, however, it appears that the increase in delivered luminosity is more than twice that due to an increase in availability credited to the more stable operating conditions during trickle operation. Further gains were made when continuous injection was extended to the high energy ring as well. In this paper we will present our operational experience as well as some of the diagnostics we use to monitor and maintain tuning of the machine in order to control injection background and protect the detector

  19. Study on the operation mode for indigenization and standardization of AP1000 technology

    International Nuclear Information System (INIS)

    Gao Zhihu; Cheng Huiping

    2014-01-01

    This paper describes the importance and necessity of developing standardized AP1000 technology, and analyzes the problems faced and measures to be taken. The operation mode, known as the Committee of AP1000 Standardized Design and Innovation Management, was first put forward in China. And the paper also discusses how to arouse the enthusiasm of the owners, designers, manufactures, as well as construction, installation, regulation and other parties, how to exploit the advantage of whole industry to promote the localization and standardization of AP1000 technology. (authors)

  20. The formation of liquid bridge in different operating modes of AFM

    Science.gov (United States)

    Wei, Zheng; Sun, Yan; Ding, WenXuan; Wang, ZaiRan

    2016-09-01

    The liquid bridge is one of the principal factors that cause artifacts in ambient-pressure atomic force microscope (AFM) images. Additionally, it is the main component of the adhesion force in ambient conditions. To understand the AFM imaging mechanism and the sample characteristics, it is essential to study the liquid bridge. This study interprets the physical mechanism involved in liquid bridge formation, which is composed of three different physical processes: the squeezing process, capillary condensation, and liquid film flow. We discuss the contributions of these three mechanisms to the volume and the capillary force of the liquid bridge in different AFM operation modes.

  1. Operation of LIA-30 linear induction accelerator in the mode of generation of two bremsstrahlung pulses

    Energy Technology Data Exchange (ETDEWEB)

    Bossamykin, V S; Gerasimov, A I; Gordeev, V S; Grishin, A V; Gritsina, V P; Tarasov, A D; Fedotkin, A S; Lazarev, S A; Averchenkov, A Ya [All-Russian Scientific Research Institute of Experimental Physics, Sarov (Russian Federation)

    1997-12-31

    The operating mode was studied of the LIA-30 linear induction accelerator ({approx} 40 MeV, {approx} 100 kA, {approx} 30 ns) with the generation of two bremsstrahlung pulses separated by a specified time interval from 0 to 5 {mu}s. In the accelerating channel an additional tube cathode was installed, and a synchronization system for two accelerating module groups triggering the formation and acceleration, at different initial times, of two annular electron beams with different outer diameters was changed. The energy limit of each beam electron acceleration can be controlled, and the energy sum limit is {<=} 540 MeV. (author). 2 tabs., 2 figs.

  2. PF-KO system for single bunch mode operation of a storage ring

    International Nuclear Information System (INIS)

    Ohgaki, H.; Sugiyama, S.; Mikado, T.; Chiwaki, M.; Yamada, K.; Suzuki, R.; Sei, N.; Noguchi, T.; Yamazaki, T.

    1994-01-01

    A new RF-KO (RF knockout) system for the single bunch mode operation of a storage ring has been developed. The knockout signal is modulated by the sum signal of the RF acceleration frequency of the storage ring and a bunch selection signal. We do not need any special device or a timing unit with this method. We obtain a high purity of bunch structure in a short knock out time. The single bunch impurity of 0.2% has been achieved. (author)

  3. Reduction of NOx emission in tangential fired - furnace by changing the, mode of operation

    International Nuclear Information System (INIS)

    Chudnovsky, B.; Talanker, A.; Levin, L.; Kahana, S

    1998-01-01

    The present work analyses tile results of tests on 575 MW units with tangential firing furnace arrangement in sub-stoichiometric combustion. Tangential firing provides good conditions for implementing sub-stoichiometric combustion owing to the delivery scheme of pulverized coal and air. The furnace was tested in several different modes of operation (Over Fire Air, Bunkers Out Of Service, Excess air, Tilt etc.) to achieve low cost NOx reduction. Actual performance data are presented based on experiments made on lEC's boiler in M.D. 'B' power station

  4. Potential Hazards Relating to Pyrolysis of c-C4F8O, n-C4F10 and c-C4F8 in selected gaseous diffusion plant operations

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    2000-01-01

    As part of a program intended to replace the present evaporative coolant at the gaseous diffusion plants (GDPs) with a non-ozone-depleting alternate, a series of investigations of the suitability of candidate substitutes is under way. This report summarizes studies directed at estimating the chemical and thermal stability of three candidate coolants, c-C 4 F 8 O, n-C 4 F 10 and c-C 4 4F 8 , in a few specific environments to be found in gaseous diffusion plant operations

  5. Radial electric field evolution in various operational modes in the TUMAN-3M tokamak

    International Nuclear Information System (INIS)

    Askinazi, L G; Kornev, V A; Krikunov, S V; Lebedev, S V; Smirnov, A I; Tukachinsky, A S; Vildjunas, M I; Zhubr, N A; Krupnik, L I; Tendler, M

    2008-01-01

    Radial electric field evolution has been studied on the TUAMN-3M tokamak in different modes of operation: ohmic and NBI heating, L- and H-modes, with and without strong MHD activity. Peripheral radial electric field was measured using Langmuire probes, which were inserted up to 2cm inside LCFS, while core plasma potential evolution was measured using HIBP diagnostic. It was found, that in presence of strong MHD activity radial electric field in a vicinity of the island changed sign from negative to positive and could reach up to 4kV/m. Central plasma potential exhibited a positive perturbation of ∼700V during the MHD burst. This positive radial electric field might lead to H-mode termination, both in ohmic and NBI heating cases. Possible mechanism of the positive E r generation, namely the electron losses along ergodized magnetic field lines in the presence of MHD-island, is discussed. The same mechanism might be responsible for the positive potential spikes during a saw-tooth crash, also observed using HIBP. Another phenomenon observed using HIBP was quasi-coherent potential oscillations with the frequency close to one of the GAM. Possible location of these oscillations in the core region r/a ∼ 0.33 is discussed

  6. Dual mode operation, highly selective nanohole array-based plasmonic colour filters

    Science.gov (United States)

    Fouladi Mahani, Fatemeh; Mokhtari, Arash; Mehran, Mahdiyeh

    2017-09-01

    Taking advantage of nanostructured metal films as plasmonic colour filters (PCFs) has been evolved remarkably as an alternative to the conventional technologies of chemical colour filtering. However, most of the proposed PCFs depict a poor colour purity focusing on generating either the additive or subtractive colours. In this paper, we present dual mode operation PCFs employing an opaque aluminium film patterned with sub-wavelength holes. Subtractive colours like cyan, magenta, and yellow are the results of reflection mode of these filters yielding optical efficiencies as high as 70%-80% and full width at half maximum of the stop-bands up to 40-50 nm. The colour selectivity of the transmission mode for the additive colours is also significant due to their enhanced performance through the utilization of a relatively thick aluminium film in contact with a modified dielectric environment. These filters provide a simple design with one-step lithography in addition to compatibility with the conventional CMOS processes. Moreover, they are polarization insensitive due to their symmetric geometry. A complete palette of pure subtractive and additive colours has been realized with potential applications, such as multispectral imaging, CMOS image sensors, displays, and colour printing.

  7. Adaptive Protection Scheme for a Distribution System Considering Grid-Connected and Islanded Modes of Operation

    Directory of Open Access Journals (Sweden)

    Yavuz Ates

    2016-05-01

    Full Text Available The renewable energy-based distributed generation (DG implementation in power systems has been an active research area during the last few decades due to several environmental, economic and political factors. Although the integration of DG offers many advantages, several concerns, including protection schemes in systems with the possibility of bi-directional power flow, are raised. Thus, new protection schemes are strongly required in power systems with a significant presence of DG. In this study, an adaptive protection strategy for a distribution system with DG integration is proposed. The proposed strategy considers both grid-connected and islanded operating modes, while the adaptive operation of the protection is dynamically realized considering the availability of DG power production (related to faults or meteorological conditions in each time step. Besides, the modular structure and fast response of the proposed strategy is validated via simulations conducted on the IEEE 13-node test system.

  8. Geometric characterization of separability and entanglement in pure Gaussian states by single-mode unitary operations

    Science.gov (United States)

    Adesso, Gerardo; Giampaolo, Salvatore M.; Illuminati, Fabrizio

    2007-10-01

    We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [S. M. Giampaolo and F. Illuminati, Phys. Rev. A 76, 042301 (2007)]. In analogy with the finite-dimensional case, we demonstrate that the 1×M bipartite entanglement of a multimode pure Gaussian state can be quantified by the minimum squared Euclidean distance between the state itself and the set of states obtained by transforming it via suitable local symplectic (unitary) operations. This minimum distance, corresponding to a , uniquely determined, extremal local operation, defines an entanglement monotone equivalent to the entropy of entanglement, and amenable to direct experimental measurement with linear optical schemes.

  9. Geometric characterization of separability and entanglement in pure Gaussian states by single-mode unitary operations

    International Nuclear Information System (INIS)

    Adesso, Gerardo; Giampaolo, Salvatore M.; Illuminati, Fabrizio

    2007-01-01

    We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [S. M. Giampaolo and F. Illuminati, Phys. Rev. A 76, 042301 (2007)]. In analogy with the finite-dimensional case, we demonstrate that the 1xM bipartite entanglement of a multimode pure Gaussian state can be quantified by the minimum squared Euclidean distance between the state itself and the set of states obtained by transforming it via suitable local symplectic (unitary) operations. This minimum distance, corresponding to a, uniquely determined, extremal local operation, defines an entanglement monotone equivalent to the entropy of entanglement, and amenable to direct experimental measurement with linear optical schemes

  10. Measurements of electron beam emittance in the Accelerator Test Facility damping ring operated in multibunch modes

    Directory of Open Access Journals (Sweden)

    Yosuke Honda

    2003-09-01

    Full Text Available We present the measurement results of electron beam emittance in the Accelerator Test Facility damping ring operated in multibunch modes. The measurements were carried out with an upgraded laser wire beam profile monitor. The monitor has now a vertical wire as well as a horizontal one and is able to make much faster measurements thanks to an increased effective laser power inside the cavity. The measured emittance shows no large bunch-to-bunch dependence in either the horizontal or vertical directions. The values of the vertical emittance are similar to those obtained in the single-bunch operation. The present results are an important step toward the realization of a high-energy linear collider.

  11. High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

    Science.gov (United States)

    Cosentino, Alberto; Mondello, Alessia; Sapia, Adalberto; D'Ottavi, Alessandro; Brotini, Mauro; Gironi, Gianna; Suetta, Enrico

    2017-11-01

    This paper describes energetic, spatial, temporal and spectral characterization measurements of the Engineering Qualification Model (EQM) of the Laser Transmitter Assembly (TXA) used in the ALADIN instrument currently under development for the ESA ADM-AEOLUS mission (EADS Astrium as prime contractor for the satellite and the instrument). The EQM is equivalent to the Flight Model, with the exception of some engineering grade components. The Laser Transmitter Assembly, based on a diode pumped tripled Nd:YAG laser, is used to generate laser pulses at a nominal wavelength of 355 nm. This laser is operated in burst mode, with a pulse repetition cycle of 100 Hz during bursts. It is capable to operate in Single Longitudinal Mode and to be tuned over 25 GHz range. An internal "network" of sensors has been implemented inside the laser architecture to allow "in flight" monitoring of transmitter. Energy in excess of 100 mJ, with a spatial beam quality factor (M2) lower than 3, a spectral linewidth less than 50 MHz with a frequency stability better than 4 MHz on short term period have been measured on the EQM. Most of the obtained results are well within the expected values and match the Instrument requirements. They constitute an important achievement, showing the absence of major critical areas in terms of performance and the capability to obtain them in a rugged and compact structure suitable for space applications. The EQM will be submitted in the near future to an Environmental test campaign.

  12. Optimization of TW accelerating structures for SLED type modes of operation

    International Nuclear Information System (INIS)

    Le Duff, J.

    1984-02-01

    The SLED method was invented at SLAC in order to produce more electron (and positron) energy from the existing klystrons. The LEP injector LINAC, also now is supposed to operate in the SLED-2 mode. At DESY similar developments have been undertaken too, to improve the linac performances. However in all cases the accelerating sections were not initially optimized for such a mode of operation, and in most cases the designers ended with long accelerating sections making a more efficient use of the klystron power, with rectangular pulses, sometimes at the expense of a longer linac. The present study deals with new approaches for designing linacs, and in particular compact linacs, considering from the beginning a pulse compression scheme, where the main feature consists of having an exponential pulse shape instead of rectangular. Moreover a detailed comparison is made between constant impedance and constant gradient travelling wave (TW) accelerating structures. As a matter of fact the constant impedance structure when optimized looks sligthy better than the second one. In addition short structures appear to be more efficient for a given number of RF sources. Consequently linear accelerators can be made more simple and less expensive, and if one allows for higher tolerable accelerating gradients they can be made even compact

  13. The acetone bandpass detector for inverse photoemission: operation in proportional and Geiger–Müller modes

    Science.gov (United States)

    Thiede, Christian; Niehues, Iris; Schmidt, Anke B.; Donath, Markus

    2018-06-01

    Inverse photoemission is the most versatile experimental tool to study the unoccupied electronic structure at surfaces of solids. Typically, the experiments are performed in the isochromat mode with bandpass photon detectors. For gas-filled counters, the bandpass behavior is realized by the combination of the photoionization threshold of the counting gas as the high-pass filter and the ultraviolet transmission cutoff of an alkaline earth fluoride entrance window as the low-pass filter. The transmission characteristics of the entrance window determine the optical bandpass. The performance of the counter depends on the composition of the detection gas and the fill-gas pressure, the readout electronics and the counter geometry. For the well-known combination of acetone and CaF2, the detector can be operated in proportional and Geiger–Müller modes. In this work, we review aspects concerning the working principles, the counter construction and the read-out electronics. We identify optimum working parameters and provide a step-by-step recipe how to build, install and operate the device.

  14. Information needs in nuclear power plants during low power operation modes

    Energy Technology Data Exchange (ETDEWEB)

    Tommila, Teemu; Fantoni, Paolo F.; Zander, Ralf M.

    1998-02-01

    During the past few years an increasing attention has been paid to the safety of shutdown and refuelling operations. It has turned out that the risks during shutdown may be comparable to the risks of power operation. The goal of this report is to identify information requirements related to low power operating modes of nuclear power plants. These include, for example, warm and cold shutdowns, refuelling and maintenance, as well as related state transitions such as start-up and shut-down. The focus of the report is on planned refuelling outages and the role of the control room in managing the outage activities. As a starting point, the basic terminology and characteristics of low power operation are discussed. The current situation at nuclear power plants and some recent developments in information technology are reviewed. End-users' requirements and enabling technologies are combined in order to identify the opportunities for new information technology tools in low power operation. The required features of process control systems and maintenance information systems are described. Common plant modelling techniques, open software architectures and functional structuring of the process control system are suggested to be the key issues in the long-term development of operator support systems. On a shorter time scale, new tools solving limited practical problems should be developed and evaluated. This would provide a basis for the features needed for low power operation, including for example, outage planning, on-line risk monitoring, management of outage tasks, adaptive alarm handling, computerised procedures and task-oriented human interfaces. (author)

  15. Analysis and Improvement of Control Algorithm for Operation Mode Transition due to Input Channel Trouble in Control Systems

    International Nuclear Information System (INIS)

    Ahn, Myunghoon; Kim, Woogoon; Yim, Hyeongsoon

    2016-01-01

    The PI (Proportional plus Integral) controller, which is the essential functional block in control systems, can automatically perform the stable control of an important plant process while reducing the steady state error and improving the transient response. However, if the received input PV (Process Variable) is not normal due to input channel trouble, it will be difficult to control the system automatically. For this reason, many control systems are implemented to change the operation mode from automatic to manual mode in the PI controller when the failed input PV is detected. If the PI controller is in automatic mode for all the time, the control signal varies as the change of the input PV is continuously reflected in the control algorithm. In the other cases, since the controller changes into the manual mode at t=0, the control signal is fixed at the last PI controller output and thus the feedback control is not performed anymore until the operator takes an action such as the operation mode change. As a result of analysis and simulations for the controller’s operation modes in all the cases of input channel trouble, we discovered that it is more appropriate to maintain the automatic mode despite the bad quality in the PV. Therefore, we improved the control system algorithm reflecting the analysis results for the operator’s convenience and the stability of a control system

  16. Analysis and Improvement of Control Algorithm for Operation Mode Transition due to Input Channel Trouble in Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Myunghoon; Kim, Woogoon; Yim, Hyeongsoon [KEPCO Engineering and Construction Co., Deajeon (Korea, Republic of)

    2016-10-15

    The PI (Proportional plus Integral) controller, which is the essential functional block in control systems, can automatically perform the stable control of an important plant process while reducing the steady state error and improving the transient response. However, if the received input PV (Process Variable) is not normal due to input channel trouble, it will be difficult to control the system automatically. For this reason, many control systems are implemented to change the operation mode from automatic to manual mode in the PI controller when the failed input PV is detected. If the PI controller is in automatic mode for all the time, the control signal varies as the change of the input PV is continuously reflected in the control algorithm. In the other cases, since the controller changes into the manual mode at t=0, the control signal is fixed at the last PI controller output and thus the feedback control is not performed anymore until the operator takes an action such as the operation mode change. As a result of analysis and simulations for the controller’s operation modes in all the cases of input channel trouble, we discovered that it is more appropriate to maintain the automatic mode despite the bad quality in the PV. Therefore, we improved the control system algorithm reflecting the analysis results for the operator’s convenience and the stability of a control system.

  17. Pulsed-mode operation and performance of a ferromagnetic shape memory alloy actuator

    International Nuclear Information System (INIS)

    Asua, E; García-Arribas, A; Etxebarria, V; Feuchtwanger, J

    2014-01-01

    The actuation capabilities and positioning performance of a single crystal ferromagnetic shape memory alloy (FSMA) operated in pulsed mode are evaluated in a prototype device. It consists of two orthogonal coil pairs that produce the magnetic fields necessary for the non-contact deformation of the material. The position of the top of the crystal after actuation is measured by a capacitive sensor. A specifically designed power module drives the discharge of a set of capacitors through the coils, producing fast current pulses of large amplitudes (about 250 A), the coil pairs are driven independently to control the direction of actuation. Open-loop experiments demonstrate that successive pulses of increasing magnitude successfully produced the desired expansion and contraction of the crystal, depending on the pair of coils that is activated. The deformation achieved is maintained after the pulses, highlighting the advantageous set-and-forget operation of the device. Closed-loop experiments are performed using a double proportional–integral–derivative controller, designed to take advantage of the energy-saving quality of the set-and-forget operation. Despite the nonlinear response and hysteric response of FSMA materials, a reference position can be reached and maintained with a maximum error of 0.5 μm. (paper)

  18. Small break LOCA analysis for YGN 5 and 6 RCP trip strategy in power mode operation

    International Nuclear Information System (INIS)

    Kim, Tech Mo; Choi, Han Rim

    2001-01-01

    A continued operation of Reactor Coolant Pumps(RCPs) during a Small Break Loss of Coolant Accident(SBLOCA) in all operation mode may increase unnecessary inventory loss from the Reactor Coolant System(RCS) causing a severe core uncovery which might lead to fuel failure. After Three Mile Island Unit 2(TMI-2) accident, the Combustion Engineering Owner Group(CEOG) developed RCP trip strategy called 'Trip-Two/Leave-Two' (T2/L2). The T2/L2 RCP trip strategy consists of tripping the first two RCPs on low RCS pressure and then tripping the remaining two RCPs if a LOCA has occurred. This analysis demonstrates the inherent safety of RCP trip strategy during an SBLOCA for Youggwang Nuclear Power Plant Unit 5 and 6(YGN 5 and 6). The trip setpoint of the first two RCPs for YGN 5 and 6 is calculated to be 1721 psia in pressurizer pressure based on the limiting SBLOCA with 0.15 ft 2 break size in the hot leg. The analysis results show that YGN 5 and 6 can maintain the core coolability even if the operator fails to trip the second two RCPs or trips at the worst time of minimum liquid inventory

  19. Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers

    Directory of Open Access Journals (Sweden)

    A. Komarov

    2012-01-01

    Full Text Available We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.

  20. Second-order sliding mode controller with model reference adaptation for automatic train operation

    Science.gov (United States)

    Ganesan, M.; Ezhilarasi, D.; Benni, Jijo

    2017-11-01

    In this paper, a new approach to model reference based adaptive second-order sliding mode control together with adaptive state feedback is presented to control the longitudinal dynamic motion of a high speed train for automatic train operation with the objective of minimal jerk travel by the passengers. The nonlinear dynamic model for the longitudinal motion of the train comprises of a locomotive and coach subsystems is constructed using multiple point-mass model by considering the forces acting on the vehicle. An adaptation scheme using Lyapunov criterion is derived to tune the controller gains by considering a linear, stable reference model that ensures the stability of the system in closed loop. The effectiveness of the controller tracking performance is tested under uncertain passenger load, coupler-draft gear parameters, propulsion resistance coefficients variations and environmental disturbances due to side wind and wet rail conditions. The results demonstrate improved tracking performance of the proposed control scheme with a least jerk under maximum parameter uncertainties when compared to constant gain second-order sliding mode control.

  1. Output Feedback Fractional-Order Nonsingular Terminal Sliding Mode Control of Underwater Remotely Operated Vehicles

    Directory of Open Access Journals (Sweden)

    Yaoyao Wang

    2014-01-01

    Full Text Available For the 4-DOF (degrees of freedom trajectory tracking control problem of underwater remotely operated vehicles (ROVs in the presence of model uncertainties and external disturbances, a novel output feedback fractional-order nonsingular terminal sliding mode control (FO-NTSMC technique is introduced in light of the equivalent output injection sliding mode observer (SMO and TSMC principle and fractional calculus technology. The equivalent output injection SMO is applied to reconstruct the full states in finite time. Meanwhile, the FO-NTSMC algorithm, based on a new proposed fractional-order switching manifold, is designed to stabilize the tracking error to equilibrium points in finite time. The corresponding stability analysis of the closed-loop system is presented using the fractional-order version of the Lyapunov stability theory. Comparative numerical simulation results are presented and analyzed to demonstrate the effectiveness of the proposed method. Finally, it is noteworthy that the proposed output feedback FO-NTSMC technique can be used to control a broad range of nonlinear second-order dynamical systems in finite time.

  2. Modeling and advanced sliding mode controls of crawler cranes considering wire rope elasticity and complicated operations

    Science.gov (United States)

    Tuan, Le Anh; Lee, Soon-Geul

    2018-03-01

    In this study, a new mathematical model of crawler cranes is developed for heavy working conditions, with payload-lifting and boom-hoisting motions simultaneously activated. The system model is built with full consideration of wind disturbances, geometrical nonlinearities, and cable elasticities of cargo lifting and boom luffing. On the basis of this dynamic model, three versions of sliding mode control are analyzed and designed to control five system outputs with only two inputs. When used in complicated operations, the effectiveness of the controllers is analyzed using analytical investigation and numerical simulation. Results indicate the effectiveness of the control algorithms and the proposed dynamic model. The control algorithms asymptotically stabilize the system with finite-time convergences, remaining robust amid disturbances and parametric uncertainties.

  3. DBD plasma source operated in single-filamentary mode for therapeutic use in dermatology

    Energy Technology Data Exchange (ETDEWEB)

    Rajasekaran, Priyadarshini; Mertmann, Philipp; Bibinov, Nikita; Awakowicz, Peter [Institute for Electrical Engineering and Plasma Technology, Ruhr-Universitaet Bochum, Universitaetsstr. 150, 44801 Bochum (Germany); Wandke, Dirk [CINOGY GmbH, Max-Naeder-Str. 15, 37114 Duderstadt (Germany); Vioel, Wolfgang, E-mail: rajasekaran@aept.rub.d, E-mail: mertmann@aept.rub.d, E-mail: Nikita.Bibinov@rub.d, E-mail: dirk.wandke@cinogy.co, E-mail: vioel@hawk-hhg.d, E-mail: awakowicz@aept.rub.d [University of Applied Sciences and Arts, Faculty of Natural Sciences and Technology, Von-Ossietzky-Str. 99, 37085 Goettingen (Germany)

    2009-11-21

    Our dielectric barrier discharge (DBD) plasma source for bio-medical application comprises a copper electrode covered with ceramic. Objects of high capacitance such as the human body can be used as the opposite electrode. In this study, the DBD source is operated in single-filamentary mode using an aluminium spike as the opposite electrode, to imitate the conditions when the discharge is ignited on a raised point, such as hair, during therapeutic use on the human body. The single-filamentary discharge thus obtained is characterized using optical emission spectroscopy, numerical simulation, voltage-current measurements and microphotography. For characterization of the discharge, averaged plasma parameters such as electron distribution function and electron density are determined. Fluxes of nitric oxide (NO), ozone (O{sub 3}) and photons reaching the treated surface are simulated. The calculated fluxes are finally compared with corresponding fluxes used in different bio-medical applications.

  4. Integrated Mode Choice, Small Aircraft Demand, and Airport Operations Model User's Guide

    Science.gov (United States)

    Yackovetsky, Robert E. (Technical Monitor); Dollyhigh, Samuel M.

    2004-01-01

    A mode choice model that generates on-demand air travel forecasts at a set of GA airports based on changes in economic characteristics, vehicle performance characteristics such as speed and cost, and demographic trends has been integrated with a model to generate itinerate aircraft operations by airplane category at a set of 3227 airports. Numerous intermediate outputs can be generated, such as the number of additional trips diverted from automobiles and schedule air by the improved performance and cost of on-demand air vehicles. The total number of transported passenger miles that are diverted is also available. From these results the number of new aircraft to service the increased demand can be calculated. Output from the models discussed is in the format to generate the origin and destination traffic flow between the 3227 airports based on solutions to a gravity model.

  5. Data-processing program from the operating modes of the nuclear reactor (P0DER)

    International Nuclear Information System (INIS)

    Totev, T.L.; Boyadzhiev, A.I.

    1981-01-01

    A program PODER for processing data from the operating modes of the reactors taking into account the effects of corrosion, hydration, and deformation of the nuclear reactor fuel element sheathing, the formation of the corrosion product deposits, the change in the geometric dimensions of the nuclear reactor fuel element due to the temperature deformation, as well as the various gas fillers, are elaborated. The ''hot channel'' method determining the reliability of the system is realized. The basic equations describing the thermohydraulic processes in nuclear reactors are solved by the finite difference method. Approximations are carried out with the approach of least squares. The temperature distribution versus the zirconium sheathing height is computed for the case of WWER-440 type reactors. The advantages of the proposed program P0DER are discussed

  6. Performance of a residential heat pump operating in the cooling mode with single faults imposed

    International Nuclear Information System (INIS)

    Kim, Minsung; Payne, W. Vance; Domanski, Piotr A.; Yoon, Seok Ho; Hermes, Christian J.L.

    2009-01-01

    The system behavior of a R410A residential unitary split heat pump operating in the cooling mode was investigated. Seven artificial faults were implemented: compressor/reversing valve leakage, improper outdoor air flow, improper indoor air flow, liquid line restriction, refrigerant undercharge, refrigerant overcharge, and presence of non-condensable gas in the refrigerant. This study monitored eight fault detection features and identified the most sensitive features for each fault. The effect of the various fault levels on energy efficiency ratio (EER) was also estimated. Since the studied system employed a thermostatic expansion valve (TXV) as an expansion device, it could adapt to some faults making the fault less detectable. The distinctiveness of the fault depended on the TXV status (fully open or not)

  7. Approach to the energetic coaxial gun of the steady-state mode operation

    International Nuclear Information System (INIS)

    Hirano, Kei-ichi

    1993-01-01

    Behaviors of a coaxial plasma gun operated in a steady-state mode have been studied. It is shown that the gun has potentialities to yield an energetic plasma beam, if a supersonic plasma flow is supplied instead of a neutral gas and if shorting out of the Hall potential is minimized on the surfaces of the electrodes. The former is necessary because a electromagnetic force chokes the subsonic flow appearing in the ionizing zone of the inlet gas. The latter is achieved if the electrodes are segmented into many insulated short elements along the axis. The required minimum number of the segmentation is estimated by the newly developed model based on the boundary layer concept. (author)

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

    Directory of Open Access Journals (Sweden)

    V. E. Bondarenko

    2017-03-01

    account operation mode of power systems and the use of software systems with imitation of instantaneous interrelated schemes of transport loads.

  9. STOMP Sparse Vegetation Evapotranspiration Model for the Water-Air-Energy Operational Mode

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Anderson L.; White, Mark D.; Freeman, Eugene J.; Zhang, Z. F.

    2005-09-15

    The Water-Air-Energy (WAE) Operational Mode of the Subsurface Transport Over Multiple Phases (STOMP) numerical simulator solves the coupled conservation equations for water mass, air mass, and thermal energy in multiple dimensions. This addendum describes the theory, input file formatting, and application of a soil-vegetation-atmosphere transfer (SVAT) scheme for STOMP that is based on a sparse vegetation evapotranspiration model. The SVAT scheme is implemented as a boundary condition on the upper surface of the computational domain and has capabilities for simulating evaporation from bare surfaces as well as evapotranspiration from sparsely vegetated surfaces populated with single or multiple plant species in response to meteorological forcings. With this extension, the model calculates water mass, air mass and thermal energy across a boundary surface in addition to root-water transport between the subsurface and atmosphere. This mode represents the barrier extension of the WAE mode and is designated as STOMP-WAE-B. Input for STOMP-WAE-B is specified via three input cards and include: atmospheric conditions through the Atmospheric Conditions Card; time-invariant plant species data through the Plant Properties Card; and time varying plant species data through the Boundary Conditions Card. Two optional cards, the Observed Data and UCODE Control Cards allow use of STOMP-WAE with UCODE in an inverse mode to estimate model parameters. STOMP-WAE was validated by solving a number of test problems from the literature that included experimental observations as well as analytical or numerical solutions. Several of the UNSAT-H verification problems are included along with a benchmark simulation derived from a recently published intercode comparison for barrier design tools. Results show that STOMP is able to meet, and in most cases, exceed performance of other commonly used simulation codes without having to resort to may of their simplifying assumptions. Use of the fully

  10. High-power and long-pulse operation of TE{sub 31,11} mode gyrotron

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Ryosuke, E-mail: ikeda.ryosuke@jaea.go.jp; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Sakamoto, Keishi

    2015-10-15

    Highlights: • We are under development of TE{sub 31,11} mode gyrotron to aim ITER specification. • HE{sub 11} mode purity reached 96% of ITER specification. • Mode competition was suppressed in initial phase of oscillation by anode voltage control. • Maximum output power of 1.2 MW was achieved. • Steady state operation of 500 MJ was achieved. - Abstract: The ITER electron cyclotron system is designed to inject a 20 MW RF beam by using twenty-four 170 GHz/1 MW gyrotrons. JAEA is currently developing a gyrotron having a high-order mode (TE{sub 31,11}) to reduce the heat load in the cavity resonator and achieve an output power greater than 1 MW. The measured radiation profile at the front of the diamond window agreed with the results of the calculation. In order to suppress RF loss in the equatorial and upper port launchers, a high-quality HE{sub 11} mode is required at the exit of the matching optics unit (MOU). An HE{sub 11} mode purity of 96% was achieved by finely adjusting the two mirrors in the MOU. During the oscillation start-up phase, mode competition with counter-rotating TE{sub 29,12} mode was observed on the higher magnetic field side which caused arcing and pressure increase in the gyrotron. To avoid the counter-rotating TE{sub 29,12} mode from being excited, a start-up scenario that controls the voltage between the anode and cathode electrodes at the initial phase of operation was introduced, which was able to achieve a stable start-up of TE{sub 31,11} mode. A 1.2 MW output power having a total electric efficiency of 43% was obtained in high-power experiments. In steady-state operation, a 1000 s oscillation length and output power of 0.51 MW was achieved.

  11. Testing to expand the rotary-mode core sampling system operating envelope

    International Nuclear Information System (INIS)

    Witwer, K.S.

    1998-01-01

    Rotary sampling using the Rotary Mode Core Sampling System (RMCSS) is constrained by what is referred to as the ''Operating Envelope''. The Operating Envelop defines the maximum downward force, maximum rotational speed and minimum purge gas flow allowed during operation of the RMCSS. The original values of 1170 lb. down force, 55 RPM rotational speed, and 30 SCFM nitrogen purge gas were determined during original envelope testing. This envelope was determined by observing the temperature rise on the bitface while drilling into waste simulants. The maximum temperature in single-shell tanks (SSTS) is considered to be approximately 9O C and the critical drill bit temperature, which is the temperature at which an exothermic reaction could be initiated in the tank waste, was previously determined to be 150 C. Thus, the drill bit temperature increase was limited to 60 C. Thermal properties of these simulants approximated typical properties of waste tank saltcake. Later, more detailed envelope testing which used a pumice block simulant, showed a notably higher temperature rise while drilling. This pumice material, which simulated a ''worst case'' foreign object embedded in the waste, has lower thermal conductivity and lower thermal diffusivity than earlier simulants. These properties caused a slower heat transfer in the pumice than in the previous simulants and consequently a higher temperature rise. The maximum downward force was subsequently reduced to 750 lb (at a maximum 55 RPM and minimum 30 SCFM purge gas flow) which was the maximum value at which the drill bit could be operated and still remain below the 60 C temperature rise

  12. Early detection of power system disturbances as a condition for safe operation of the Dukovany NPP in the 'Island operation mode'

    International Nuclear Information System (INIS)

    Petruzela, I.

    1997-01-01

    The ''Frequency Plan'' worked out for the Czech Power System specifies a set of preventive measures along with the set of the frequency ranges. This problem was solved in details for the Dukovany nuclear power plant. The design changes under preparation support a reliable as well as safe operation in the island-operation mode until a full restoration of the whole power system. The design modifications are based on the following three main innovations: An incorporation of the FREA 16 frequency relay into the protection circuits; large modifications in turbine control loops; installation of software routine for the operator to support the island operation mode. The capability of the island operation has been demanded by relevant regulations both for the operating units and for that under construction. The capability can be tested under the transition to houseloads, as well as through the direct simulation of abnormal grid conditions. 1 fig

  13. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    International Nuclear Information System (INIS)

    Sarkar, C; Hirani, H

    2013-01-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel–Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0–2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear. (paper)

  14. High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

    Science.gov (United States)

    Cosentino, Alberto; Mondello, Alessia; Sapia, Adalberto; D'Ottavi, Alessandro; Brotini, Mauro; Nava, Enzo; Stucchi, Emanuele; Trespidi, Franco; Mariottini, Cristina; Wazen, Paul; Falletto, Nicolas; Fruit, Michel

    2017-11-01

    This paper describes the laser transmitter assembly used in the ALADIN instrument currently in C/D development phase for the ESA ADM-AEOLUS mission (EADS Astrium as prime contractor for the satellite and the instrument). The Laser Transmitter Assembly (TXA), based on a diode pumped tripled Nd:YAG laser, is used to generate tunable laser pulses of 150 mJ at a nominal wavelength of 355 nm. This laser is operated in burst mode, with a pulse repetition cycle of 100 Hz. The TXA is composed of the following units: a diodepumped CW Nd:YAG Laser named Reference Laser Head (RLH), used to inject a diode-pumped, Q-switched, amplified and frequency tripled Nd:YAG Laser working in the third harmonic referred as Power Laser Head (PLH) and a Transmitter Laser Electronics (TLE) containing all the control and power electronics needed for PLH and RLH operation. The TXA is made by an European consortium under the leadership of Galileo Avionica (It), and including CESI (It), Quantel (Fr), TESAT (Ge) and Thales (Fr).

  15. Wind Farm-LA Coordinated Operation Mode and Dispatch Model in Wind Power Accommodation Promotion

    Directory of Open Access Journals (Sweden)

    Li Lin

    2018-05-01

    Full Text Available With the support of a smart grid, a load aggregator (LA that aggregates the demand response resources of small- and medium-sized customers to participate in the electricity market would be a novel way to promote wind power accommodation. This paper proposes a wind farm–LA coordinated operation mode (WLCOM, which enables LAs to deal with wind farms directly at an agreement price. Afterwards, according to the accommodation demand of the wind farm, a coordinated dispatch model taking advantage of the various response capabilities of different flexible loads is set up to maximize the revenue of the LA. A case study was conducted to demonstrate the effectiveness of the proposed WLCOM and the coordinated dispatch model. The demonstration indicates that: (a load fluctuations and wind curtailment were obviously reduced; and (b both the LA and the wind farm participating in coordinated operation obtained higher revenues. Factors that influence the accommodation level, as well as revenues of wind farms and LA, are also investigated.

  16. Analysis of doubly-fed induction machine operating at motoring mode subjected to voltage sag

    Directory of Open Access Journals (Sweden)

    Navneet Kumar

    2016-09-01

    Full Text Available Variable Speed (VS Pumped Storage Plants (PSP equipped with large asynchronous (Doubly-Fed Induction machines are emerging now in hydropower applications. Motoring mode of operation of Doubly-Fed Induction Machine (DFIM is essential and techno-economical in this application due to: (1 its uniqueness in active power controllability, (2 bulk power handing capability with less rated power converters in rotor circuit, and (3 integrating Renewable Energy Sources (RES. This paper investigates the performance of two DFIMs at different power ratings (2.2 kW and 2 MW under voltage sag with different attribute. The test results are analyzed in terms of the peaks in torque, speed, power taken and transient currents in rotor and stator circuits. During sag, stable region for DFIM operation along with speed and stator side reactive power input control is also illustrated. The negative effects of voltage sag are briefly discussed. MATLAB simulation is validated with experimentation. The various observations during simulation and experimental analysis are also supported by the theoretical explanations.

  17. Control scheme for direct steam generation in parabolic troughs under recirculation operation mode

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, L.; Zarza, E. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, P.O. Box 22, E-04200 Tabernas, Almeria (Spain); Berenguel, M. [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, E-04120 Almeria (Spain); Camacho, E.F. [Universidad de Sevilla, Dpto. de Ingenieria de Sistemas y Automatica, Camino de los Descubrimientos s/n, E-41092 Sevilla (Spain)

    2006-01-15

    Electricity production using solar thermal energy is one of the main research areas at present in the field of renewable energies, these systems being characterised by the need of reliable control systems aimed at maintaining desired operating conditions in the face of changes in solar radiation, which is the main source of energy. A new prototype of solar system with parabolic trough collectors was implemented at the Plataforma Solar de Almeria (PSA, South-East Spain) to investigate the direct steam generation process under real solar conditions in the parabolic solar collector field of a thermal power plant prototype. This paper presents details and some results of the application of a control scheme designed and tested for the recirculation operation mode, for which the main objective is to obtain steam at constant temperature and pressure at the outlet of the solar field, so that changes produced in the inlet water conditions and/or solar radiation will only affect the amount of steam produced by the solar field. The steam quality and consequently the nominal efficiency of the plant are thus maintained. (author)

  18. Solar-assisted absorption air-conditioning systems in buildings: Control strategies and operational modes

    International Nuclear Information System (INIS)

    Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.

    2016-01-01

    Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage

  19. Gravitationally induced zero modes of the Faddeev-Popov operator in the Coulomb gauge for Abelian gauge theories

    Science.gov (United States)

    Canfora, Fabrizio; Giacomini, Alex; Oliva, Julio

    2010-08-01

    It is shown that on curved backgrounds, the Coulomb gauge Faddeev-Popov operator can have zero modes even in the Abelian case. These zero modes cannot be eliminated by restricting the path integral over a certain region in the space of gauge potentials. The conditions for the existence of these zero modes are studied for static spherically symmetric spacetimes in arbitrary dimensions. For this class of metrics, the general analytic expression of the metric components in terms of the zero modes is constructed. Such expression allows one to find the asymptotic behavior of background metrics, which induce zero modes in the Coulomb gauge, an interesting example being the three-dimensional anti-de Sitter spacetime. Some of the implications for quantum field theory on curved spacetimes are discussed.

  20. High beta tokamak operation in DIII-D limited at low density/collisionality by resistive tearing modes

    International Nuclear Information System (INIS)

    La Haye, R.J.; Lao, L.L.; Strait, E.J.; Taylor, T.S.

    1997-01-01

    The maximum operational high beta in single-null divertor (SND) long pulse tokamak discharges in the DIII-D tokamak with a cross-sectional shape similar to the proposed International Thermonuclear Experimental Reactor (ITER) device is found to be limited by the onset of resistive instabilities that have the characteristics of neoclassically destabilized tearing modes. There is a soft limit due to the onset of an m/n=3/2 rotating tearing mode that saturates at low amplitude and a hard limit at slightly higher beta due to the onset of an m/n=2/1 rotating tearing mode that grows, slows down and locks. By operating at higher density and thus collisionality, the practical beta limit due to resistive tearing modes approaches the ideal magnetohydrodynamic (MHD) limit. (author). 15 refs, 4 figs

  1. Grid-Forming-Mode Operation of Boost-Power-Stage Converter in PV-Generator-Interfacing Applications

    Directory of Open Access Journals (Sweden)

    Jukka Viinamäki

    2017-07-01

    Full Text Available The application of constant power control and inclusion of energy storage in grid-connected photovoltaic (PV energy systems may increase the use of two-stage system structures composed of DC–DC-converter-interfaced PV generator and grid-connected inverter connected in cascade. A typical PV-generator-interfacing DC–DC converter is a boost-power-stage converter. The renewable energy system may operate in three different operation modes—grid-forming, grid-feeding, and grid-supporting modes. In the last two operation modes, the outmost feedback loops are taken from the input terminal of the associated power electronic converters, which usually does not pose stability problems in terms of their input sources. In the grid-forming operation mode, the outmost feedback loops have to be connected to the output terminal of the associated power electronic converters, and hence the input terminal will behave as a negative incremental resistor at low frequencies. This property will limit the operation of the PV interfacing converter in either the constant voltage or constant current region of the PV generator for ensuring stable operation. The boost-power-stage converter can be applied as a voltage or current-fed converter limiting the stable operation region accordingly. The investigations of this paper show explicitly that only the voltage-fed mode would provide feasible dynamic and stability properties as a viable interfacing converter.

  2. Dual fuel mode operation in diesel engines using renewable fuels: Rubber seed oil and coir-pith producer gas

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhas, A.S.; Jayaraj, S.; Muraleedharan, C. [Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut-673601 (India)

    2008-09-15

    Partial combustion of biomass in the gasifier generates producer gas that can be used as supplementary or sole fuel for internal combustion engines. Dual fuel mode operation using coir-pith derived producer gas and rubber seed oil as pilot fuel was analyzed for various producer gas-air flow ratios and at different load conditions. The engine is experimentally optimized with respect to maximum pilot fuel savings in the dual fuel mode operation. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual-fuel mode of operation with oil-coir-pith operation is found to be in the higher side at all load conditions. Exhaust emission was found to be higher in the case of dual fuel mode of operation as compared to neat diesel/oil operation. Engine performance characteristics are inferior in fully renewable fueled engine operation but it suitable for stationary engine application, particularly power generation. (author)

  3. Residential CCHP microgrid with load aggregator: Operation mode, pricing strategy, and optimal dispatch

    International Nuclear Information System (INIS)

    Gu, Wei; Lu, Shuai; Wu, Zhi; Zhang, Xuesong; Zhou, Jinhui; Zhao, Bo; Wang, Jun

    2017-01-01

    Highlights: •A bilateral transaction mode for the residential CCHP microgrid is proposed. •An energy pricing strategy for the residential CCHP system is proposed. •A novel integrated demand response for the residential loads is proposed. •Two-stage operation optimization model for the CCHP microgrid is proposed. •Operations of typical days and annual scale of the CCHP microgrid are studied. -- Abstract: As the global energy crisis, environmental pollution, and global warming grow in intensity, increasing attention is being paid to combined cooling, heating, and power (CCHP) systems that realize high-efficiency cascade utilization of energy. This paper proposes a bilateral transaction mechanism between a residential CCHP system and a load aggregator (LA). The variable energy cost of the CCHP system is analyzed, based on which an energy pricing strategy for the CCHP system is proposed. Under this pricing strategy, the electricity price is constant, while the heat/cool price is ladder-shaped and dependent on the relationship between the electrical, heat, and cool loads. For the LA, an integrated demand response program is proposed that combines electricity-load shifting and a flexible heating/cooling supply, in which a thermodynamic model of buildings is used to determine the appropriate range of heating/cooling supply. Subsequently, a two-stage optimal dispatch model is proposed for the energy system that comprises the CCHP system and the LA. Case studies consisting of three scenarios (winter, summer, and excessive seasons) are delivered to demonstrate the effectiveness of the proposed approach, and the performance of the proposed pricing strategy is also evaluated by annual operation simulations.

  4. Degradation of chlorpyrifos contaminated soil by bioslurry reactor operated in sequencing batch mode: bioprocess monitoring

    International Nuclear Information System (INIS)

    Mohan, S. Venkata; Sirisha, K.; Rao, N. Chandrasekhara; Sarma, P.N.; Reddy, S. Jayarama

    2004-01-01

    Bioslurry reactor (SS-SBR) was studied for the degradation of chlorpyrifos contaminated soil using native mixed microflora, by adopting sequencing batch mode (anoxic-aerobic-anoxic) operation. Reactor operation was monitored for a total cycle period of 72 h consisting of 3 h of FILL, 64 h REACT, 2 h of SETTLE, and 3 h of DECANT with chlorpyrifos concentrations of 3000 μg/g, 6000 μg/g and 12000 μg/g. At 3000 μg/g of chlorpyrifos concentration, 91% was degraded after 72 h of the cycle period, whereas in the case of 6000 μg/g of chlorpyrifos, 82.5% was degraded. However, for 12000 μg/g of chlorpyrifos, only 14.5% degradation was observed. The degradation rate was rapid at lower substrate concentration and 12000 μg/g of substrate concentration was found to be inhibitory. Chlorpyrifos removal rate was slow during the initial phase of the sequence operation. Half-life of chlorpyrifos degradation (t 0.5 ) was estimated to be 6.3 h for 3000 μg/g of substrate, 17.5 h for 6000 μg/g and 732.2 h for 12000 μg/g. Process performance was assessed by monitoring chlorpyrifos concentration and biochemical process parameters viz., pH, oxidation and reduction potential (ORP), dissolved oxygen (DO), oxygen consumption rate (OCR) and microbial count (CFU) during sequence operation. From the experimental data obtained it can be concluded that the rate-limiting step with the bioslurry phase reactor in the process of chlorpyrifos degradation may be attributed to the concentration of substrate present in either soil or liquid phase. Periodic operations (SBR) by varying individual components of substrate with time in each process step place micro-organisms under nutritional changes from feast to famine and maintains a wide distribution in the population of micro-organisms resulting in high uptake of the substrate in the bioslurry reactor

  5. Degradation of chlorpyrifos contaminated soil by bioslurry reactor operated in sequencing batch mode: bioprocess monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, S. Venkata [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Sirisha, K. [Electrochemical Research Laboratories, Department of Chemistry, Sri Venkateswara University, Tirupati 517502 (India); Rao, N. Chandrasekhara [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Sarma, P.N. [Biochemical and Environmental Engineering Centre, Indian Institute of Chemical Technology, Hyderabad 500007 (India); Reddy, S. Jayarama [Electrochemical Research Laboratories, Department of Chemistry, Sri Venkateswara University, Tirupati 517502 (India)]. E-mail: profjreddy_s@yahoo.co.in

    2004-12-10

    Bioslurry reactor (SS-SBR) was studied for the degradation of chlorpyrifos contaminated soil using native mixed microflora, by adopting sequencing batch mode (anoxic-aerobic-anoxic) operation. Reactor operation was monitored for a total cycle period of 72 h consisting of 3 h of FILL, 64 h REACT, 2 h of SETTLE, and 3 h of DECANT with chlorpyrifos concentrations of 3000 {mu}g/g, 6000 {mu}g/g and 12000 {mu}g/g. At 3000 {mu}g/g of chlorpyrifos concentration, 91% was degraded after 72 h of the cycle period, whereas in the case of 6000 {mu}g/g of chlorpyrifos, 82.5% was degraded. However, for 12000 {mu}g/g of chlorpyrifos, only 14.5% degradation was observed. The degradation rate was rapid at lower substrate concentration and 12000 {mu}g/g of substrate concentration was found to be inhibitory. Chlorpyrifos removal rate was slow during the initial phase of the sequence operation. Half-life of chlorpyrifos degradation (t{sub 0.5}) was estimated to be 6.3 h for 3000 {mu}g/g of substrate, 17.5 h for 6000 {mu}g/g and 732.2 h for 12000 {mu}g/g. Process performance was assessed by monitoring chlorpyrifos concentration and biochemical process parameters viz., pH, oxidation and reduction potential (ORP), dissolved oxygen (DO), oxygen consumption rate (OCR) and microbial count (CFU) during sequence operation. From the experimental data obtained it can be concluded that the rate-limiting step with the bioslurry phase reactor in the process of chlorpyrifos degradation may be attributed to the concentration of substrate present in either soil or liquid phase. Periodic operations (SBR) by varying individual components of substrate with time in each process step place micro-organisms under nutritional changes from feast to famine and maintains a wide distribution in the population of micro-organisms resulting in high uptake of the substrate in the bioslurry reactor.

  6. Development of a numerical tool to study the mixing phenomenon occurring during mode one operation of a multi-mode ejector-augmented pulsed detonation rocket engine

    Science.gov (United States)

    Dawson, Joshua

    A novel multi-mode implementation of a pulsed detonation engine, put forth by Wilson et al., consists of four modes; each specifically designed to capitalize on flow features unique to the various flow regimes. This design enables the propulsion system to generate thrust through the entire flow regime. The Multi-Mode Ejector-Augmented Pulsed Detonation Rocket Engine operates in mode one during take-off conditions through the acceleration to supersonic speeds. Once the mixing chamber internal flow exceeds supersonic speed, the propulsion system transitions to mode two. While operating in mode two, supersonic air is compressed in the mixing chamber by an upstream propagating detonation wave and then exhausted through the convergent-divergent nozzle. Once the velocity of the air flow within the mixing chamber exceeds the Chapman-Jouguet Mach number, the upstream propagating detonation wave no longer has sufficient energy to propagate upstream and consequently the propulsive system shifts to mode three. As a result of the inability of the detonation wave to propagate upstream, a steady oblique shock system is established just upstream of the convergent-divergent nozzle to initiate combustion. And finally, the propulsion system progresses on to mode four operation, consisting purely of a pulsed detonation rocket for high Mach number flight and use in the upper atmosphere as is needed for orbital insertion. Modes three and four appear to be a fairly significant challenge to implement, while the challenge of implementing modes one and two may prove to be a more practical goal in the near future. A vast number of potential applications exist for a propulsion system that would utilize modes one and two, namely a high Mach number hypersonic cruise vehicle. There is particular interest in the dynamics of mode one operation, which is the subject of this research paper. Several advantages can be obtained by use of this technology. Geometrically the propulsion system is fairly

  7. Multiple-bunch-length operating mode design for a storage ring using hybrid low alpha and harmonic cavity method

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Weiwei, E-mail: gaomqr@mail.ustc.edu.cn [College of Mathematics and Physics, Fujian University of Technology, Fuzhou 350118 (China); Wang, Lin; Li, Heting [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)

    2017-03-11

    In this paper we design a simultaneous three bunch length operating mode at the HLS-II (Hefei Light Source II) storage ring by installing two harmonic cavities and minimizing the momentum compaction factor. The short bunches (2.6 mm) presented in this work will meet the requirement of coherent millimeter-wave and sub-THz radiation experiments, while the long bunches (20 mm) will efficiently increase the total beam current. Therefore, this multiple-bunch-length operating mode allows present synchrotron users and coherent millimeter-wave users (or sub THz users) to carry out their experiments simultaneously. Since the relatively low energy characteristic of HLS-II we achieve the multiple-bunch-length operating mode without multicell superconducting RF cavities, which is technically feasible.

  8. Operational conditions and characteristics of ELM-events during H-mode plasmas in the stellarator W7-AS

    International Nuclear Information System (INIS)

    Hirsch, M.; Grigull, P.; Wobig, H.; Kisslinger, J.; McCormick, K.; Anton, M.; Baldzuhn, J.; Fiedler, S.; Fuchs, Ch.; Geiger, J.; Giannone, L.; Hartfuss, H.-J.; Holzhauer, E.; Hirsch, M.; Jaenicke, R.; Kick, M.; Maassberg, H.; Wagner, F.; Weller, A.

    2000-01-01

    H-mode operation in the low-shear stellarator W7-AS is achieved for specific plasma edge topologies characterized by three 'operational windows' of the edge rotational transform. An explanation for this strong influence of the magnetic configuration could be the increase of viscous damping if rational surfaces and thus island structures occur within the relevant plasma edge layer, thereby impeding the development of an edge transport barrier. Prior to the final transition to a quiescent state, the plasma edge passes a rich phenomenology of dynamic behaviour such as dithering and ELMs. Plasma edge parameters indicate that a quiescent H-mode occurs if a certain edge pressure is achieved. (author)

  9. Analysis and interpretation of the performance degradation of glass Resistive Plate Chambers operated in streamer mode

    CERN Document Server

    Calcaterra, A; Patteri, P; Piccolo, M; Della Mea, G; Restello, S; Ferri, F; Musella, P; Redaelli, N; Tabarelli de Fatis, T; Tinti, G; Mannocchi, G; Trinchero, G

    2007-01-01

    The long-term stability of Resistive Plate Chambers (RPCs) with glass electrodes was studied for one year with a dedicated test station hosting about 10 m2 of detectors. RPCs were operated in streamer mode with a ternary gas mixture containing argon (27%), isobutane (9%) and tetrafluoroethane (64%). Environmental conditions were kept under control and, in particular, the water pollution in the gas, deemed responsible for the degradation of glass RPC performance, was monitored never to exceed 30 ppm in the exhaust line. Evidence for a substantial aging of the detectors was observed, resulting in a loss of efficiency correlated to an increased rate of spurious streamers. This can be ascribed to the chemical attack of the glass surface by hydrofluoric acid formed in the streamer process, as confirmed by detailed morphological and chemical analyses of the electrode surface. Our results strengthen the indication that the instability of glass RPCs in the long term is related to the use of fluorocarbons as quenching...

  10. Characterization of a pixelated CdTe Timepix detector operated in ToT mode

    International Nuclear Information System (INIS)

    Billoud, T.; Leroy, C.; Papadatos, C.; Roux, J.S.; Pichotka, M.; Pospisil, S.

    2017-01-01

    A 1 mm thick CdTe sensor bump-bonded to a Timepix readout chip operating in Time-over-Threshold (ToT) mode has been characterized in view of possible applications in particle and medical physics. The CdTe sensor layer was segmented into 256 × 256 pixels, with a pixel pitch of 55  μm. This CdTe Timepix device, of ohmic contact type, has been exposed to alpha-particles and photons from an 241 Am source, photons from a 137 Cs source, and protons of different energies (0.8–10 MeV) delivered by the University of Montreal Tandem Accelerator. The device was irradiated on the negatively biased backside electrode. An X-ray per-pixel calibration commonly used for this type of detector was done and its accuracy and resolution were assessed and compared to those of a 300  μm thick silicon Timepix device. The electron mobility-lifetime product (μ e τ e ) of CdTe for protons of low energy has been obtained from the Hecht equation. Possible polarization effects have been also investigated. Finally, information about the homogeneity of the detector was obtained from X-ray irradiation.

  11. Multiobjective Optimization of a Counterrotating Type Pump-Turbine Unit Operated at Turbine Mode

    Directory of Open Access Journals (Sweden)

    Jin-Hyuk Kim

    2014-05-01

    Full Text Available A multiobjective optimization for improving the turbine output and efficiency of a counterrotating type pump-turbine unit operated at turbine mode was carried out in this work. The blade geometry of both the runners was optimized using a hybrid multiobjective evolutionary algorithm coupled with a surrogate model. Three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump-turbine unit. As major hydrodynamic performance parameters, the turbine output and efficiency were selected as objective functions with two design variables related to the hub profiles of both the runner blades. These objectives were numerically assessed at twelve design points selected by Latin hypercube sampling in the design space. Response surface approximation models for the objectives were constructed based on the objective function values at the design points. A fast nondominated sorting genetic algorithm for the local search coupled with the response surface approximation models was applied to determine the global Pareto-optimal solutions. The trade-off between the two objectives was determined and described with respect to the Pareto-optimal solutions. The results of this work showed that the turbine outputs and efficiencies of optimized pump-turbine units were simultaneously improved in comparison to the reference unit.

  12. Monte-Carlo study of ICRF-sustained mode operation in tandem mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Todd, A.M.M. (Grumman Aerospace Corp., Princeton, NJ (USA))

    1984-09-01

    A study, using a Monte-Carlo simulation code, of ICRF-sustained mode operation in tandem mirrors by way of ICRF end-cell fuelling and heating is described. Although the basic parameter space considered corresponds to the Phaedrus experiment, the central-cell density and temperatures are extended towards the reactor regime. It is found that significant end cell ion potential barriers can be generated with ICRF, but that, owing to choking of the central-cell ion source stream by the plugging potential, saturation occurs and power requirements rapidly increase, so that the potential rise is limited to about twice the central-cell ion temperature. Although performance is improved as the ion cyclotron resonance approaches the end-cell mid-plane, no significant difference is found between inboard, outboard or double resonance location. As the central-cell density and temperatures are increased, the RF power requirement is found to increase dramatically. Optimum performance for end cell fuelling results when the central-cell electron temperature is higher than the ion temperature, but the magnitude of this ratio is limited by an increase in threshold power level with electron temperature.

  13. Cross focusing of mixed mode operation in an extra dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Soni, V S; Nayyar, V P [Punjabi Univ., Patiala (India). Dept. of Physics

    1979-08-01

    This paper presents a study of the nonlinear propagation of a mixture of two degenerate modes (TEM/sub 00/ and TEM/sub 10/) of a high power laser beam in an extradense plasma. The high irradiance inhomogeneous laser beam creates an electron density gradient region in the overdense plasma (n > nsub(c)) through which the beam can propagate. The focusing effects have been studied for different power ratios of the two modes (TEM/sub 00/ mode is considered to be stronger than the TEM/sub 10/ mode). Self-focusing of the beam in x and y directions for critical power has been extensively studied.

  14. Operating modes of high-Tc composite superconductors and thermal runaway conditions under current charging

    International Nuclear Information System (INIS)

    Romanovskii, V R; Watanabe, K

    2006-01-01

    The operating thermal and electric modes of a high-T c superconducting composite in partially and fully penetrated states induced by the charging current are investigated. They were studied under conditions in which the current charging rate, the volume fraction of the superconductor in a composite or the temperature of the cooling bath were changed. The transient behaviour of the voltage-current dependence, which is characteristic during stable and unstable increases in electric field inside the composite under a continuous current charging, is discussed. Simulations were done using zero- and one-dimensional steady and unsteady thermoelectric models with a power equation describing the virgin voltage-current characteristic of a superconductor. It is found that some thermoelectric trends underlie the shape of the voltage-current characteristic of the high-T c superconducting composite. These have to be considered during experiments in which the critical or quench currents are defined. First, in the initial stage of the fully penetrated regime (in the low voltage range), the electric field distribution does not have a uniform character. These states depend on the volume fraction of the superconductor and the current charging rate: the higher these quantities, the higher the heterogeneity of the electric field. Second, during the stable over-critical regime (in the high voltage range) occurring in complete penetration modes, the evolution of the electric field may depend on the relevant temperature increase of a composite according to the corresponding increase in its temperature-dependent heat capacity. Consequently, the shape of the voltage-current characteristic of a composite high-T c superconductor during continuous current charging, both before and after thermal runaway, has only a positive slope. Moreover, it is proved that the growth of the fully penetrated part of the voltage-current characteristic becomes less intensive when the current charging rate or the

  15. Reactor-relevant quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields

    International Nuclear Information System (INIS)

    Burrell, K. H.; Garofalo, A. M; Osborne, T. H.; Schaffer, M. J.; Snyder, P. B.; Solomon, W. M.; Park, J.-K.; Fenstermacher, M. E.

    2012-01-01

    Results from recent experiments demonstrate that quiescent H-mode (QH-mode) sustained by magnetic torque from non-axisymmetric magnetic fields is a promising operating mode for future burning plasmas. Using magnetic torque from n=3 fields to replace counter-I p torque from neutral beam injection (NBI), we have achieved long duration, counter-rotating QH-mode operation with NBI torque ranging from counter-I p to up to co-I p values of 1-1.3 Nm. This co-I p torque is 3 to 4 times the scaled torque that ITER will have. These experiments utilized an ITER-relevant lower single-null plasma shape and were done with ITER-relevant values of ν ped * and β N ped . These discharges exhibited confinement quality H 98y2 =1.3, in the range required for ITER. In preliminary experiments using n=3 fields only from a coil outside the toroidal coil, QH-mode plasmas with low q 95 =3.4 have reached fusion gain values of G=β N H 89 /q 95 2 =0.4, which is the desired value for ITER. Shots with the same coil configuration also operated with net zero NBI torque. The limits on G and co-I p torque have not yet been established for this coil configuration. QH-mode work to has made significant contact with theory. The importance of edge rotational shear is consistent with peeling-ballooning mode theory. Qualitative and quantitative agreements with the predicted neoclassical toroidal viscosity torque is seen.

  16. Experimental investigation of limit space charge accumulation mode operation in a semi-insulating GaAs photoconductive semiconductor switch

    International Nuclear Information System (INIS)

    Ma Xiangrong; Shi Wei; Xiang Mei

    2013-01-01

    Experiments with the limited space-charge accumulation (LSA) mode of oscillation in a large gap semi-insulating (SI) GaAs photoconductive semiconductor switch (PCSS) are discussed. It has been observed that growth and drift of a photo-activated charge domain (PACD) are quenched only when the bias voltage is more than twice the threshold voltage. The original negative resistance characteristics are directly utilized in the LSA mode; during LSA operation the spatial average of the electric field varies over a large portion of the negative differential mobility region of the velocity—electric field characteristic. The work efficiency of an SI GaAs PCSS is remarkably enhanced by electric field excursions into the positive resistance region when the total electric field is only below the threshold part of the time. The LSA mode can only operate in the certain conditions that satisfy the quenching of the accumulation layer and the smaller initial domain voltage. (semiconductor devices)

  17. Efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser.

    Science.gov (United States)

    Wang, P; Cooper, L J; Sahu, J K; Clarkson, W A

    2006-01-15

    A novel approach to achieving robust single-spatial-mode operation of cladding-pumped fiber lasers with multimode cores is reported. The approach is based on the use of a fiber geometry in which the core has a helical trajectory within the inner cladding to suppress laser oscillation on higher-order modes. In a preliminary proof-of-principle study, efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser with a 30 microm diameter core and a numerical aperture of 0.087 has been demonstrated. The laser yielded 60.4 W of output at 1043 nm in a beam with M2 clad fiber lasers.

  18. Discovery of multiple, ionization-created CS2 anions and a new mode of operation for drift chambers

    International Nuclear Information System (INIS)

    Snowden-Ifft, Daniel P.

    2014-01-01

    This paper focuses on the surprising discovery of multiple species of ionization-created CS 2 anions in gas mixtures containing electronegative CS 2 and O 2 , identified by their slightly different drift velocities. Data are presented to understand the formation mechanism and identity of these new anions. Regardless of the micro-physics, however, this discovery offers a new, trigger-less mode of operation for the drift chambers. A demonstration of trigger-less operation is presented

  19. The Effects of 10 Communication Modes on the Behavior of Teams During Co-Operative Problem-Solving

    Science.gov (United States)

    Ochsman, Richard B.; Chapanis, Alphonse

    1974-01-01

    Sixty teams of two college students each solved credible "real world" problems co-operatively. Conversations were carried on in one of 10 modes of communication: (1) typewriting only, (2) handwriting only, (3) handwriting and typewriting, (4) typewriting and video, (5) handwriting and video, (6) voice only, (7) voice and typewriting, (8) voice and…

  20. Adaptive Droop Control Applied to Voltage-Source Inverters Operating in Grid-Connected and Islanded Modes

    DEFF Research Database (Denmark)

    Vasquez, J. C.; Guerrero, J. M.; Luna, A.

    2009-01-01

    This paper proposes a novel control for voltagesource inverters with the capability to flexibly operate in gridconnected and islanded modes. The control scheme is based on the droop method, which uses some estimated grid parameters such as the voltage and frequency and the magnitude and angle of ...

  1. How Mode of Delivery Affects Comprehension of an Operations Management Simulation: Online vs Face-to-Face Classrooms

    Science.gov (United States)

    Riley, Jason M.; Ellegood, William A.; Solomon, Stanislaus; Baker, Jerrine

    2017-01-01

    Purpose: This study aims to understand how mode of delivery, online versus face-to-face, affects comprehension when teaching operations management concepts via a simulation. Conceptually, the aim is to identify factors that influence the students' ability to learn and retain new concepts. Design/methodology/approach: Leveraging Littlefield…

  2. New Three-Mode Squeezing Operators Gained via Tripartite Entangled State Representation

    International Nuclear Information System (INIS)

    Jiang Nianquan; Fan Hongyi

    2008-01-01

    We show that the Agarwal-Simon representation of single-mode squeezed states can be generalized to find new form of three-mode squeezed states. We use the tripartite entangled state representations |p,y,z> and |x,u,v> to realize this goal.

  3. Vibration energy harvesting based on integrated piezoelectric components operating in different modes.

    Science.gov (United States)

    Hu, Junhui; Jong, Januar; Zhao, Chunsheng

    2010-01-01

    To increase the vibration energy-harvesting capability of the piezoelectric generator based on a cantilever beam, we have proposed a piezoelectric generator that not only uses the strain change of piezoelectric components bonded on a cantilever beam, but also employs the weights at the tip of the cantilever beam to hit piezoelectric components located on the 2 sides of weights. A prototype of the piezoelectric generator has been fabricated and its characteristics have been measured and analyzed. The experimental results show that the piezoelectric components operating in the hit mode can substantially enhance the energy harvesting of the piezoelectric generator on a cantilever beam. Two methods are used and compared in the management of rectified output voltages from different groups of piezoelectric components. In one of them, the DC voltages from rectifiers are connected in series, and then the total DC voltage is applied to a capacitor. In another connection, the DC voltage from each group is applied to different capacitors. It is found that 22.3% of the harvested energy is wasted due to the series connection. The total output electric energy of our piezoelectric generator at nonresonance could be up to 43 nJ for one vibration excitation applied by spring, with initial vibration amplitude (0-p) of 18 mm and frequency of 18.5 Hz, when the rectified voltages from different groups of piezoelectric components are connected to their individual capacitors. In addition, the motion and impact of the weights at the tip of the cantilever beam are theoretically analyzed, which well explains the experimental phenomena and suggests the measures to improve the generator.

  4. Spin wave mode coexistence on the nanoscale: A consequence of the Oersted field induced asymmetric energy landscape

    Science.gov (United States)

    Dumas, Randy

    2014-03-01

    The emerging field of magnonics relies on the systematic generation, manipulation, and detection of spin waves (SWs). Nanocontact spin torque oscillators (NC-STOs) provide an ideal platform to study spin transfer torque induced SW emission. In analogy to two species competing for the same food supply it has been argued that only one SW mode can survive in the steady state. However, as evidenced in many experiments clear signatures of mode-hopping are often observed. Here, we present a third possibility, namely that under the correct experimental conditions, mode coexistencecan be realized in NC-STOs. Micromagnetic simulations reveal that the SW modes are spatially separated under the NC. Mode coexistence is facilitated by the local field asymmetries induced by the spatially inhomogeneous Oersted field in the vicinity of the NC and further promoted by SW localization. Finally, both simulation and experiment reveal a weak low frequency signal exactly at the difference of the mode frequencies, consistent with inter-modulation of two coexistent modes. The Swedish Research Council, The Swedish Foundation for Strategic Research, and the Knut and Alice Wallenberg Foundation are acknowledged. ANL is a US DOE Science Laboratory operated under contract no. DE-AC02-06CH11357 by UChicago Argonne, LLC.

  5. Acquisition performance of LAPAN-A3/IPB multispectral imager in real-time mode of operation

    Science.gov (United States)

    Hakim, P. R.; Permala, R.; Jayani, A. P. S.

    2018-05-01

    LAPAN-A3/IPB satellite was launched in June 2016 and its multispectral imager has been producing Indonesian coverage images. In order to improve its support for remote sensing application, the imager should produce images with high quality and quantity. To improve the quantity of LAPAN-A3/IPB multispectral image captured, image acquisition could be executed in real-time mode from LAPAN ground station in Bogor when the satellite passes west Indonesia region. This research analyses the performance of LAPAN-A3/IPB multispectral imager acquisition in real-time mode, in terms of image quality and quantity, under assumption of several on-board and ground segment limitations. Results show that with real-time operation mode, LAPAN-A3/IPB multispectral imager could produce twice as much as image coverage compare to recorded mode. However, the images produced in real-time mode will have slightly degraded quality due to image compression process involved. Based on several analyses that have been done in this research, it is recommended to use real-time acquisition mode whenever it possible, unless for some circumstances that strictly not allow any quality degradation of the images produced.

  6. INTEGRAL INDEX OF OPERATION QUALITY FOR EVALUATION OF IMPACT OF DISTRIBUTIVE GENERATION SOURCES ON ELECTRIC NETWORK MODES

    Directory of Open Access Journals (Sweden)

    Petro D. Lezhniuk

    2017-06-01

    Full Text Available Method of operation quality evaluation of electric network, comprising renewable sources of energy (RSE is considered. Integral index that enables to evaluate the impact of RSE on energy losses and its quality as well as balance reliability in electric network is suggested. Mathematical model is constructed, taking into account the assumption that electric network with RSE may be in various operation modes, characterized by different technical economic indices. To determine the integral index of operation quality of electric network with RSE in all possible states tools of Markov processes theory and criterial method are used.

  7. A 9.61-W, b-cut Tm,Ho:YAP laser in Q-switched mode operation

    Science.gov (United States)

    Li, Guoxing; Yang, Xining; Zhang, Ziqiu; Zhang, Hongda; Zhang, Liang

    2018-02-01

    A high energy of b-cut Tm, Ho:YAlO3 laser is reported in the paper. The laser operated in acousto-optical Qswitched mode at 2.12 μm. The output average power of 9.61 W was achieved at the pulse repetition frequency of 10 kHz ,and the power of 11.6 W was acquired in continuous wave mode. Moreover, the energy per pulse of 0.961 mJ in 64.4 ns was acquired at 10 kHz with a 14.92-kW peak power.

  8. Comparative Analysis of Battery Behavior with Different Modes of Discharge for Optimal Capacity Sizing and BMS Operation

    OpenAIRE

    Mazhar Abbas; Eung-sang Kim; Seul-ki Kim; Yun-su Kim

    2016-01-01

    Battery-operated systems are always concerned about the proper management and sizing of a battery. A Traditional Battery Management System (BMS) only includes battery-aware task scheduling based on the discharge characteristics of a whole battery pack and do not take into account the mode of the load being served by the battery. On the other hand, an efficient and intelligent BMS should monitor the battery at a cell level and track the load with significant consideration of the load mode. Dep...

  9. Model-Based Resource and Mode Management for Lunar Surface Operations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is aimed at developing a model based resource and mode management system for space robotics systems that will allow real time assessment of...

  10. Performance enhancement of high-field asymmetric waveform ion mobility spectrometry by applying differential-RF-driven operation mode.

    Science.gov (United States)

    Zeng, Yue; Tang, Fei; Zhai, Yadong; Wang, Xiaohao

    2017-09-01

    The traditional operation mode of high-field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) uses a one-way radio frequency (RF) voltage input as the dispersion voltage. This requires a high voltage input and limits power consumption reduction and miniaturization of instruments. With higher dispersion voltages or larger compensation voltages, there also exist problems such as low signal intensity or the fact that the dispersion voltage is no longer much larger than the compensation voltage. In this paper, a differential-RF-driven operation mode of FAIMS is proposed. The two-way RF is used to generate the dispersion field, and a phase difference is added between the two RFs to generate a single step waveform field. Theoretical analysis, and experimental results from an ethanol sample, showed that the peak positions of the ion spectra changed linearly (R 2 = 0.9992) with the phase difference of the two RFs in the differential-RF-driven mode and that the peak intensity of the ion spectrum could be enhanced by more than eight times for ethanol ions. In this way, it is possible to convert the ion spectrum peaks outside the separation or compensation voltage range into a detectable range, by changing the phase difference. To produce the same separation electric field, the high-voltage direct current input voltage can be maximally reduced to half of that in the traditional operation mode. Without changing the drift region size or drift condition, the differential-RF-driven operation mode can reduce power consumption, increase signal-to-noise ratio, extend the application range of the dispersion voltage and compensation voltage, and improve FAIMS detection performance.

  11. Thermo-mechanical and damage analyses of EAST carbon divertor under type-I ELMy H-mode operation

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.X. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Song, Y.T. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Ye, M.Y. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Peng, X.B., E-mail: pengxb@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wu, S.T. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Qian, X.Y.; Zhu, C.C. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China)

    2016-04-15

    Highlights: • Type-I ELMy H-mode is one of the most severe operating environment in tokamak. • An actual time-history heat load has been used in thermo-mechanical analysis. • The analysis results are time-dependent during the whole discharge process. • The analysis could be very useful in evaluating the operational capability of the divertor. - Abstract: The lower carbon divertor has been used since 2008 in EAST, and many significant physical results, like the 410 s long pulse discharge and the 32 s H-mode operation, have been achieved. As the carbon divertor will still be used in the next few years while the injected auxiliary heating power would be increased gradually, it’s necessary to evaluate the operational capability of the carbon divertor under the heat loads during future operation. In this paper, an actual time-history heat load during type-I ELMy H-mode from EAST experiment, as one of the most severe operating environment in tokamak, has been used in the calculation and analysis. The finite element (FE) thermal and mechanical calculations have been carried out to analysis the stress and deformation of the carbon divertor during the heat loads. According to the results, the main impact on the overall temperature comes from the relative stable phase before and after the type-I ELMs and local peak load, and the transient thermal load such as type-I ELMy only has a significant effect on the surface temperature of the graphite tiles. The carbon divertor would work with high stress near the screw bolts in the current operational conditions, because of high preload and conservative frictional coefficient between the bolts and heatsink. For the future operation, new plasma facing materials (PFM) and divertor technology should be developed.

  12. Passive mode-locking dynamics in a 3.1GHz quantum dot laser diode operating around 1.5μm

    NARCIS (Netherlands)

    Tahvili, M.S.; Heck, M.J.R.; Nötzel, R.; Smit, M.K.; Bente, E.A.J.M.

    2010-01-01

    We report on passive mode-locking in a 3.1GHz InAs/InP(100) quantum dot laser diode operating around 1.5µm. The range of stable passive mode-locking, detailed measurements of the linewidth of the optical modes and the phase modulation in output pulses are presented.

  13. A MATHEMATICAL MODEL OF THERMAL POWER PLANTS SMOKE EXHAUSTERS INDUCTION MOTORS SYSTEM OPERATION MODES

    Directory of Open Access Journals (Sweden)

    K. M. Vasyliv

    2017-06-01

    Full Text Available Purpose. Development of a model-software complex (MSC for computer analysis of modes of the system of induction motors (IM of smoke exhausters of thermal power plant (TPP, the basic elements of which are mathematical models and corresponding software written in the programming language FORTRAN. Methodology. Mathematical model serves as a system of differential equations of electrical and mechanical condition. The equation of electric state is written in phase coordinates based on Kirchhoff's laws, and mechanical condition described by the d'Alembert equation. Mathematical model focuses on explicit numerical integration methods. Scientific novelty. The equation of state of electrical connections takes into account the mutual electromagnetic circuits for transformer of own needs (TON and induction motors and interdependence (in all possible combinations between: TON (from which motors powered and each of the two IM and blood pressure between themselves. The complex allows to simulate electromagnetic and electromechanical processes in transitional and steady, symmetric and asymmetric modes including modes of self-induction motors. Results. Complex is used for computer analysis of electromagnetic and electromechanical processes and established the basic laws of motion modes of starting, stopping and self-start of IM of smoke exhausters of the TPP unit. Practical value. The complex is suitable for computer analysis of modes of other similar units of own needs of thermal power plants.

  14. Effect of Wave Accessibility on Lower Hybrid Wave Current Drive in Experimental Advanced Superconductor Tokamak with H-Mode Operation

    International Nuclear Information System (INIS)

    Li Xin-Xia; Xiang Nong; Gan Chun-Yun

    2015-01-01

    The effect of the wave accessibility condition on the lower hybrid current drive in the experimental advanced superconductor Tokamak (EAST) plasma with H-mode operation is studied. Based on a simplified model, a mode conversion layer of the lower hybrid wave between the fast wave branch and the slow wave branch is proved to exist in the plasma periphery for typical EAST H-mode parameters. Under the framework of the lower hybrid wave simulation code (LSC), the wave ray trajectory and the associated current drive are calculated numerically. The results show that the wave accessibility condition plays an important role on the lower hybrid current drive in EAST plasma. For wave rays with parallel refractive index n ‖ = 2.1 or n ‖ = 2.5 launched from the outside midplane, the wave rays may penetrate the core plasma due to the toroidal geometry effect, while numerous reflections of the wave ray trajectories in the plasma periphery occur. However, low current drive efficiency is obtained. Meanwhile, the wave accessibility condition is improved if a higher confined magnetic field is applied. The simulation results show that for plasma parameters under present EAST H-mode operation, a significant lower hybrid wave current drive could be obtained for the wave spectrum with peak value n ‖ = 2.1 if a toroidal magnetic field B T = 2.5 T is applied. (paper)

  15. H-mode pedestal and threshold studies over an expanded operating space on Alcator C-Moda)

    Science.gov (United States)

    Hubbard, A. E.; Hughes, J. W.; Bespamyatnov, I. O.; Biewer, T.; Cziegler, I.; LaBombard, B.; Lin, Y.; McDermott, R.; Rice, J. E.; Rowan, W. L.; Snipes, J. A.; Terry, J. L.; Wolfe, S. M.; Wukitch, S.

    2007-05-01

    This paper reports on studies of the edge transport barrier and transition threshold of the high confinement (H) mode of operation on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)], over a wide range of toroidal field (2.6-7.86T) and plasma current (0.4-1.7MA). The H-mode power threshold and edge temperature at the transition increase with field. Barrier widths, pressure limits, and confinement are nearly independent of field at constant current, but the operational space at high B shifts toward higher temperature and lower density and collisionality. Experiments with reversed field and current show that scrape-off-layer flows in the high-field side depend primarily on configuration. In configurations with the B ×∇B drift away from the active X-point, these flows lead to more countercurrent core rotation, which apparently contributes to higher H-mode thresholds. In the unfavorable case, edge temperature thresholds are higher, and slow evolution of profiles indicates a reduction in thermal transport prior to the transition in particle confinement. Pedestal temperatures in this case are also higher than in the favorable configuration. Both high-field and reversed-field results suggest that parameters at the L-H transition are influencing the evolution and parameters of the H-mode pedestal.

  16. Enhancement of single mode operation in coaxial optical waveguide using DB boundary conditions

    Science.gov (United States)

    Lohia, Pooja; Prajapati, Y.; Saini, J. P.; Rai, B. S.

    2014-11-01

    In this study, a competent numerical strategy to compute the dispersion of optical waveguides is presented and propagation of electromagnetic waves in a coaxial optical waveguide with DB boundary conditions is instigated. For this intend, cylindrical coordinates are here being used to derive the DB boundary conditions and to obtain field components for the modes. The propagation constant for the waveguide to be studied is determined by solving the Bessel and the modified Bessel functions. The cutoff frequencies for various lower order modes have been calculated and their dispersion characteristics are plotted correspondingly. The behavior of the coaxial optical waveguide under DB boundary conditions is shown to be significantly different from that of coaxial optical waveguide and conventional optical waveguide under traditional or tangential boundary conditions. Finally, the effect of waveguide dimensions on the mode cutoff frequencies and fabrication issues are also addressed.

  17. Stable Single-Mode Operation of Distributed Feedback Quantum Cascade Laser by Optimized Reflectivity Facet Coatings

    Science.gov (United States)

    Wang, Dong-Bo; Zhang, Jin-Chuan; Cheng, Feng-Min; Zhao, Yue; Zhuo, Ning; Zhai, Shen-Qiang; Wang, Li-Jun; Liu, Jun-Qi; Liu, Shu-Man; Liu, Feng-Qi; Wang, Zhan-Guo

    2018-02-01

    In this work, quantum cascade lasers (QCLs) based on strain compensation combined with two-phonon resonance design are presented. Distributed feedback (DFB) laser emitting at 4.76 μm was fabricated through a standard buried first-order grating and buried heterostructure (BH) processing. Stable single-mode emission is achieved under all injection currents and temperature conditions without any mode hop by the optimized antireflection (AR) coating on the front facet. The AR coating consists of a double layer dielectric of Al2O3 and Ge. For a 2-mm laser cavity, the maximum output power of the AR-coated DFB-QCL was more than 170 mW at 20 °C with a high wall-plug efficiency (WPE) of 4.7% in a continuous-wave (CW) mode.

  18. Application in low level counting of corona counters operating in voltage or current pulse recording modes

    International Nuclear Information System (INIS)

    Oravec, J.; Usacev, S.; Duka-Zojomi, A.; Sitar, B.; Benovic, D.; Holy, K.

    1977-01-01

    The advantages of current or voltage modes of recording are discussed. It appears that the current mode is more advantageous in measurements of rare events caused by highly ionizing particles on a high background of weakly ionizing particles. A 2.3 litre multiwire corona counter was used for the determination of 226 Ra content in drinking water. The 226 Ra content was estimated by measuring 222 Rn activity. The minimum measurable activity of the system was 0.07 pCi/l of water. (author)

  19. Results from prototypes of environmental and health alarm devices based on gaseous detectors operating in air in counting mode

    CERN Document Server

    Martinengo, P; Peskov, V; Benaben, P; Charpak, G; Breuil, P

    2011-01-01

    We have developed and successfully tested two prototypes of detectors of dangerous gases based on wire-type counters operating in air in avalanche mode: one is for radon (Rn) detection whereas the other one is for the detection of gases with an ionization potential less than the air components. Due to the operation in pulse counting mode these prototypes have sensitivities comparable to (in the case of the Rn detector) or much higher than (in the case of the detector for low ionization gases) the best commercial devices currently available on the market. We believe that due to their high sensitivity, simplicity and low cost such new detectors will find massive applications. One of them, discussed in this paper, could be the on-line monitoring of Rn for the prediction of earthquakes. (C) 2010 Elsevier B.V. All rights reserved.

  20. Study of accelerated unit unloading mode initiated by turbine feed pump trip with TVSA fuel assemblies operation in WWER-1000

    International Nuclear Information System (INIS)

    Borysenko, V.I.; Kadenko, I.N.; Samoilenko, D.V.

    2012-01-01

    This paper provides the study results of accelerated unit unloading mode (AUU) initiated at WWER-1000 unit operated at 100 % power and its expediency in the event of single Turbo Feed Pump (TFP) failure. Modeling was performed using an advanced calculation code RELAP/SCDAPSIM/Mod3.4 and relevant model for KhNPP Unit No. 2. As the study shows, SCRAM cannot be prevented in case of failure of 3 main circulation pumps due to steam generators (SG) level drop. Based on the results obtained, it is reasonably justified to allow SCRAM signal instead of AUU activation in case of single TFP failure at power level more than 90 % of N n om. This will provide more sparing temperature modes for fuel assemblies and equipment, as well as prevent additional thermal cycling loads and violation of safe operation limits as SG water levels

  1. On the sloshing free surface in the draft tube cone of a Francis turbine operating in synchronous condenser mode

    Science.gov (United States)

    Vagnoni, E.; Andolfatto, L.; Avellan, F.

    2017-04-01

    Hydropower plants may be required to operate in synchronous condenser mode in order to supply reactive power to the grid for compensating the fluctuations introduced by the intermittent renewable energies such wind and solar. When operating in this mode, the tail water in the Francis turbine or pump-turbine is depressed below the runner by injecting pressurized air in order to spin in air to reduce the power consumption. Many air-water interaction phenomena occur in the machine causing air losses and a consequent power consumption to recover the air lost. In this paper, the experimental investigation of the sloshing motion in the cone of a dewatered Francis turbine performed by image visualization and pressure measurements is presented. The developed image post processing method for identifying the amplitude and frequency of the oscillation of the free surface is described and the results obtained are illustrated and discussed.

  2. Performance comparison of three-phase flux reversal permanent magnet motors in BLDC and BLAC operation mode

    International Nuclear Information System (INIS)

    Stumberger, B.; Stumberger, G.; Hadziselimovic, M.; Hamler, A.; Gorican, V.; Jesenik, M.; Trlep, M.

    2008-01-01

    The paper presents a comparison of torque capability and flux-weakening performance of three-phase flux reversal permanent magnet motors with surface and inset permanent magnets. Finite element analysis is employed to determine the performance of each motor in BLDC and BLAC operation mode. It is shown that the torque capability and flux-weakening performance of surface or inset permanent magnet configuration is strongly dependent on the stator teeth number/rotor pole number combination

  3. Compact, Low-Noise Magnetic Sensor with Fluxgate (DC) and Induction (AC) Modes of Operation

    Science.gov (United States)

    2009-07-01

    induction sensor and the fluxgate magnetometer . ......................................... 2 Figure 3.1 - Impulse response of a 4” long coil (#6...Block diagram of the Year 2, Task 2 fluxgate magnetometer . ................................... 6 Figure 3.3 - FIS-prototype magnetic-field...and demonstrated an innovative dual-mode, fluxgate -induction sensor (FIS) that combines a fluxgate magnetometer and an electromagnetic (EM) induction

  4. A novel L-shaped linear ultrasonic motor operating in a single resonance mode

    Science.gov (United States)

    Zhang, Bailiang; Yao, Zhiyuan; Liu, Zhen; Li, Xiaoniu

    2018-01-01

    In this study, a large thrust linear ultrasonic motor using an L-shaped stator is described. The stator is constructed by two mutually perpendicular rectangular plate vibrators, one of which is mounted in parallel with the slider to make the motor structure to be more compact. The symmetric and antisymmetric modes of the stator based on the first order bending vibration of two vibrators are adopted, in which each resonance mode is assigned to drive the slider in one direction. The placement of piezoelectric ceramics in a stator could be determined by finite element analysis, and the influence of slots in the head block on the vibration amplitudes of driving foot was studied as well. Three types of prototypes (non-slotted, dual-slot, and single-slot) were fabricated and experimentally investigated. Experimental results demonstrated that the prototype with one slot exhibited the best mechanical output performance. The maximum loads under the excitation of symmetric mode and antisymmetric mode were 65 and 90 N, respectively.

  5. User Influence on MIMO Channel Capacity for Handsets in Data Mode Operation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan Radkov; Bonev, Ivan Bonev

    2012-01-01

    The current paper concerns realistic evaluation of the capacity of the MIMO channel between a BS and handheld device, such as a PDA or smartphone, held in front of the user’s body (data mode). The work is based on measurements of the MIMO channel between two widely separated BSs in a micro...

  6. User Influence on the Mean Effective Gain for Data Mode Operation of Mobile Handsets

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan Radkov; Bonev, Ivan Bonev

    2012-01-01

    and 2300 MHz). The handsets were of different types (bar, clamshell, smartphone), all had two antennas and were used in data (browsing) mode. All handsets were measured with twelve different users with both one-hand and two-hand grips. The body loss, the mean difference between the MEG in free space...

  7. Operational limits of high density H-modes in ASDEX Upgrade

    International Nuclear Information System (INIS)

    Mertens, V.; Borrass, K.; Kaufmann, M.; Lang, P.T.; Lang, R.; Mueller, H.W.; Neuhauser, J.; Schneider, R.; Schweinzer, J.; Suttrop, W.

    2001-01-01

    Systematic investigations of H-mode density limit (H→L-mode back transition) plasmas with gas fuelling and alternatively with additional pellet injection from the magnetic high-field-side HFS are being performed in the new closed divertor configuration DV-II. The resulting database covering a wide range of the externally controllable plasma parameters I p , B t and P heat confirms that the H-mode threshold power exceeds the generally accepted prediction P L→H heat ∝B-bar t dramatically when one approaches Greenwald densities. Additionally, in contrast to the Greenwald scaling a moderate B t -dependence of the H-mode density limit is found. The limit is observed to coincide with divertor detachment and a strong increase of the edge thermal transport, which has, however, no detrimental effect on global τ E . The pellet injection scheme from the magnetic high-field-side HFS, developed recently on ASDEX Upgrade, leads to fast particle drifts which are, contrary to the standard injection from the low-field-side, directed into the plasma core. This improves markedly the pellet particle fuelling efficiency. The responsible physical mechanism, the diamagnetic particle drift of the pellet ablatant was successfully verified recently. Other increased particle losses on respectively different time scales after the ablation process, however, still persist. Generally, a clear gain in achievable density and plasma stored energy is achieved with stationary HFS pellet injection compared to gas-puffing. (author)

  8. Improvement of the reliability graph with general gates to analyze the reliability of dynamic systems that have various operation modes

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Seung Ki [Div. of Research Reactor System Design, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); No, Young Gyu; Seong, Poong Hyun [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2016-04-15

    The safety of nuclear power plants is analyzed by a probabilistic risk assessment, and the fault tree analysis is the most widely used method for a risk assessment with the event tree analysis. One of the well-known disadvantages of the fault tree is that drawing a fault tree for a complex system is a very cumbersome task. Thus, several graphical modeling methods have been proposed for the convenient and intuitive modeling of complex systems. In this paper, the reliability graph with general gates (RGGG) method, one of the intuitive graphical modeling methods based on Bayesian networks, is improved for the reliability analyses of dynamic systems that have various operation modes with time. A reliability matrix is proposed and it is explained how to utilize the reliability matrix in the RGGG for various cases of operation mode changes. The proposed RGGG with a reliability matrix provides a convenient and intuitive modeling of various operation modes of complex systems, and can also be utilized with dynamic nodes that analyze the failure sequences of subcomponents. The combinatorial use of a reliability matrix with dynamic nodes is illustrated through an application to a shutdown cooling system in a nuclear power plant.

  9. Improvement of the reliability graph with general gates to analyze the reliability of dynamic systems that have various operation modes

    International Nuclear Information System (INIS)

    Shin, Seung Ki; No, Young Gyu; Seong, Poong Hyun

    2016-01-01

    The safety of nuclear power plants is analyzed by a probabilistic risk assessment, and the fault tree analysis is the most widely used method for a risk assessment with the event tree analysis. One of the well-known disadvantages of the fault tree is that drawing a fault tree for a complex system is a very cumbersome task. Thus, several graphical modeling methods have been proposed for the convenient and intuitive modeling of complex systems. In this paper, the reliability graph with general gates (RGGG) method, one of the intuitive graphical modeling methods based on Bayesian networks, is improved for the reliability analyses of dynamic systems that have various operation modes with time. A reliability matrix is proposed and it is explained how to utilize the reliability matrix in the RGGG for various cases of operation mode changes. The proposed RGGG with a reliability matrix provides a convenient and intuitive modeling of various operation modes of complex systems, and can also be utilized with dynamic nodes that analyze the failure sequences of subcomponents. The combinatorial use of a reliability matrix with dynamic nodes is illustrated through an application to a shutdown cooling system in a nuclear power plant

  10. Experimental Investigation of Operation of VVER Steam Generator in Condensation Mode in the Event of the Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Andrey [Institute for Physics and Power Engineering by A.I. Leypunsky, 1 Bondarenko sq. Obninsk, 249033 (Russian Federation)

    2008-07-01

    For new Russian nuclear power plants with VVER-1200 reactor in the event of a beyond design basis accident, provision is made for the use of passive safety systems for necessary core cooling. These safety systems include the passive heat removal system (PHRS). In the case of leakage in the primary circuit this system assures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam. As a result, the condensate from SG arrives at the core providing its additional cooling. To investigate the condensation mode of VVER SG operation, a large scale HA2M-SG test facility was constructed. The rig incorporates: buffer tank, SG model with scale is 1:46, PHRS heat exchanger. Experiments at the test facility have been performed to investigate condensation mode of operation of SG model at the pressure 0.4 MPa, correspond to VVER reactor pressure at the last stage of the beyond design basis accident. The report presents the test procedure and the basic obtained test results. (authors)

  11. Experimental study and performance analysis of a thermoelectric cooling and heating system driven by a photovoltaic/thermal system in summer and winter operation modes

    International Nuclear Information System (INIS)

    He, Wei; Zhou, JinZhi; Chen, Chi; Ji, Jie

    2014-01-01

    Highlights: • Thermoelectric heating system driven by heat pipe PV/T system was built and test. • Theoretical analysis has been done and simulation results have been validated by experiments. • The energetic efficiency and exergetic efficiency in summer and winter operation mode was analyzed and compared. - Abstract: This paper presents theoretical and experimental investigations of the winter operation mode of a thermoelectric cooling and heating system driven by a heat pipe photovoltaic/thermal (PV/T) panel. And the energy and exergy analysis of this system in summer and winter operation modes are also done. The winter operation mode of this system is tested in an experimental room which temperature is controlled at 18 °C. The results indicate the average coefficient of performance (COP) of thermoelectric module of this system can be about 1.7, the electrical efficiency of the PV/T panel can reach 16.7%, and the thermal efficiency of this system can reach 23.5%. The energy and exergy analysis show the energetic efficiency of the system in summer operation mode is higher than that of it in winter operation mode, but the exergetic efficiency in summer operation mode is lower than that in winter operation mode, on the contrary

  12. Fuel element cladding state change mathematical model for a WWER-1000 plant operated in the mode of varying loading

    Directory of Open Access Journals (Sweden)

    S. N. Pelykh

    2010-09-01

    Full Text Available Main features of a fuel element cladding state change mathematical model for a WWER-1000 reactor plant operated in the mode of varying loading are listed. The integrated model is based on the energy creep theory, uses the finite element method for imultaneous solution of the fuel element heat conduction and mechanical deformation equa-tions. Proposed mathematical model allows us to determine the influence of the WWER-1000 regime parameters and fuel assembly design characteristics on the change of cladding properties under different loading conditions of normal operation, as well as the cladding limiting state at variable loading depending on the length, depth and number of cycles.

  13. Observation of a High Performance Operating Regime with Small Edge-Localized Modes in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Maingi, R.; Tritz, K.; Fredrickson, E.D.; Menard, J.E.; Sabbagh, S.A.; Stutman, D.; Bell, M.G.; Bell, R.E.; Bush, C.E.; Gates, D.A.; Johnson, D.W.; Kaita, R.; Kaye, S.M.; Kugel, H.W.; LeBlanc, B.P.; Mueller, D.; Raman, R.; Roquemore, A.L.; Soukhanovskii, V.A.

    2004-01-01

    We report observation of a high performance scenario in the National Spherical Torus Experiment with very small edge-localized modes (ELMs). These ELMs have no measurable impact on stored energy and are consistent with high bootstrap current operation with line average density approaching Greenwald scaling. The ELM perturbation is observed to typically originate near the lower divertor region, as opposed to the outer midplane for ELMs described in the literature. If extrapolable, this scenario would provide an attractive operating regime for next step fusion experiments

  14. Calibration and fluctuation of the secular frequency peak amplitude versus initial condition distribution of the ion cloud confined into a three-dimensional quadrupole ion trap using a fourier transform operating mode and a steady ion flow injection mode

    International Nuclear Information System (INIS)

    Janulyte, A.; Andre, J.; Carette, M.; Mercury, M.; Reynard, C; Zerega, Y.

    2009-01-01

    A specific Fourier transform operating mode is applied to a 3-dimensional quadrupolar ion trap for mass analysis (Fourier Transform Quadrupolar Ion Trap (FTQIT) Operating Mode or Mass Spectrometer). With this operating mode, an image signal, which is representative of the collective motion of simultaneously confined ions, is made up from a set of recorded time-of-flight histograms. In an ion trap, the secular frequency of ion motion depends on m/Z ratio of the ion. By Fourier transformation of the image signal, one observes the frequency peak of each confined ionic species. When only one ionic species is confined, the peak amplitude is proportional to the maximal amplitude of the image signal. The maximal amplitude of the image signal is expressed according to the operating parameters, the initial conditions of the ions and the number of ions. Simulation tools lead to fluctuation calculation of the maximal amplitude of the image signal. Two origins are explored: (1) the fluctuation of the numbers of ions according to the steady ion flow injection mode (SIFIM) used with this operating mode and (2) the distribution fluctuation of the initial positions and velocities. Initial confinement conditions, obtained with SIFIM injection mode, lead to optimal detection with small fluctuations of the peak amplitude for Fourier transform operating mode applied to an ion trap. (authors)

  15. Determination Of Maximum Power Of The RSG-Gas At Power Operation Mode Using One Line Cooling System

    International Nuclear Information System (INIS)

    Hastuti, Endiah Puji; Kuntoro, Iman; Darwis Isnaini, M.

    2000-01-01

    In the frame of minimizing the operation-cost, operation mode using one line cooling system is being evaluated. Maximum reactor power shall be determined to assure that the existing safety criteria are not violated. The analysis was done by means of a core thermal hydraulic code, COOLOD-N. The code solves core thermal hydraulic equation at steady state conditions. By varying the reactor power as the input, thermal hydraulic parameters such as fuel cladding and fuel meat temperatures as well as safety margin against flow instability were calculated. Imposing the safety criteria to the results, maximum permissible power for this operation was obtained as much as 17.1 MW. Nevertheless, for operation the maximum power is limited to 15MW

  16. Development of Abnormal Operating Strategies for Loss of Ultimate Heat Sink (LOUHS) at Shutdown Mode in Westinghouse Type Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Duk-Joo; Lee, Seung-Chan; Sung, Je-Joong; Ha, Sang Jun [KHNP CRI, Daejeon (Korea, Republic of); Hwang, Su-Hyun [FNC Tech. Co., Yongin (Korea, Republic of)

    2016-10-15

    Loss of all AC power is classified as one of multiple failure accident by regulatory guide of Korean accident management program. Therefore we need develop strategies for the abnormal operating procedure both of power operating and shutdown mode. This paper developed abnormal operating guideline for loss of all AC power by analysis of accident scenario in pressurized water reactor. This paper analyzed the extended SBO in shutdown operating mode and developed the operating strategy of the abnormal operation procedure. Operator action for the emergency are not required to take in 500 minutes and 60 minutes in intact and opened RCS state respectively.

  17. Near-roadway monitoring of vehicle emissions as a function of mode of operation for light-duty vehicles.

    Science.gov (United States)

    Wen, Dongqi; Zhai, Wenjuan; Xiang, Sheng; Hu, Zhice; Wei, Tongchuan; Noll, Kenneth E

    2017-11-01

    Determination of the effect of vehicle emissions on air quality near roadways is important because vehicles are a major source of air pollution. A near-roadway monitoring program was undertaken in Chicago between August 4 and October 30, 2014, to measure ultrafine particles, carbon dioxide, carbon monoxide, traffic volume and speed, and wind direction and speed. The objective of this study was to develop a method to relate short-term changes in traffic mode of operation to air quality near roadways using data averaged over 5-min intervals to provide a better understanding of the processes controlling air pollution concentrations near roadways. Three different types of data analysis are provided to demonstrate the type of results that can be obtained from a near-roadway sampling program based on 5-min measurements: (1) development of vehicle emission factors (EFs) for ultrafine particles as a function of vehicle mode of operation, (2) comparison of measured and modeled CO 2 concentrations, and (3) application of dispersion models to determine concentrations near roadways. EFs for ultrafine particles are developed that are a function of traffic volume and mode of operation (free flow and congestion) for light-duty vehicles (LDVs) under real-world conditions. Two air quality models-CALINE4 (California Line Source Dispersion Model, version 4) and AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model)-are used to predict the ultrafine particulate concentrations near roadways for comparison with measured concentrations. When using CALINE4 to predict air quality levels in the mixing cell, changes in surface roughness and stability class have no effect on the predicted concentrations. However, when using AERMOD to predict air quality in the mixing cell, changes in surface roughness have a significant impact on the predicted concentrations. The paper provides emission factors (EFs) that are a function of traffic volume and mode of

  18. Utilizing foreign operating experience to derive reliability data - especially for common mode failures

    International Nuclear Information System (INIS)

    Bongartz, R.; Hennings, W.; Meessen, H.

    1987-11-01

    Failure rates for common mode failures of redundant components of the same design are derived from abnormal occurrences in safety systems of US nuclear power stations for use on a national level. The available raw data of interest for pumps and valves (processed Licensee Event Reports) are progressively re-evaluated and checked for transferability of German conditions. Most of the common mode failures (CMF) experienced affected only part of the redundancies; the homogeneous Marshall-Olkin model is therefore used to determine failure rates for both partial and total failures of redundant components. Some few results based on zero failure statistics and a small data base (four-train systems) seem to be too conservative. On the whole, however, the application of the data determined here does not provide any unrealistically high system unavailabilities. (orig.) [de

  19. Chapter 7: High-Density H-Mode Operation in ASDEX Upgrade

    International Nuclear Information System (INIS)

    Stober, Joerg Karl; Lang, Peter Thomas; Mertens, Vitus

    2003-01-01

    Recent results are reported on the maximum achievable H-mode density and the behavior of pedestal density and central density peaking as this limit is approached. The maximum achievable H-mode density roughly scales as the Greenwald density, though a dependence on B t is clearly observed. In contrast to the stiff temperature profiles, the density profiles seem to allow more shape variation and especially with high-field-side pellet-injection, strongly peaked profiles with good confinement have been achieved. Also, spontaneous density peaking at high densities is observed in ASDEX Upgrade, which is related to the generally observed large time constants for the density profile equilibration. The equilibrated density profile shapes depend strongly on the heat-flux profile in the sense that central heating leads to significantly flatter profiles

  20. High-Q, in-plane modes of nanomechanical resonators operated in air

    Science.gov (United States)

    Waggoner, Philip S.; Tan, Christine P.; Bellan, Leon; Craighead, Harold G.

    2009-05-01

    Nanomechanical resonators have traditionally been limited to use in vacuum due to low quality factors that come as a result of viscous damping effects in air or liquid. We have fabricated arrays of 90 nm thick trampoline-shaped resonators, studied their resonant frequency spectrum as a function of pressure, and found that some high frequency modes exhibit quality factors over 2000 at atmospheric pressure. We have excited the in-plane resonances of these devices, verified their identities both experimentally and with finite element modeling, and demonstrated their advantageous characteristics for ambient sensing. Even after deposition of a relatively thick polymer layer, the in-plane resonant modes still boast quality factors on the order of 2000. These results show promise for the use of nanomechanical resonant sensors in real-time atmospheric sensing applications.

  1. Method of detection of transition radiation by wire chambers operating in self-quenching streamer mode

    International Nuclear Information System (INIS)

    Akopdzhanov, G.A.; Bityukov, S.I.; Dzhelyadin, R.I.; Zaitsev, A.M.; Lapin, V.V.; Saraikin, A.I.

    1984-01-01

    A method for detecting X-ray transition radiation against the background of the signal from relativistic charged particles is suggested that is based on the use of peculiarities of the development of self-queenching streamer mode. The self-qunching streamer discharge in the Xe + isobutane mixture is experimentally registered. The effect of separation of signals from the relativistic particle and from soft X-ray, is obtained

  2. Kinetics of Grinding of Secondary Serpentine Raw Material at Cascade Operating Mode

    Directory of Open Access Journals (Sweden)

    Marek Matik

    2004-12-01

    Full Text Available The paper deals with the grinding of secondary serpentine material from the Dobšiná´s heap in a ball ceramic mill. The raw material was pre-sieved to prepare fraction of +250 –1,000 µm that was fed to the mill. During batch experiment an amount of oversize on the screen with a mesh size of 200 µm was observed as a function of time. Two speed modes were tested. Firstly, it was the mode designed by mill producer implicit from the structure of milling stand equipped by electromotor, friction gear onto driving shaft with given diameter. The speed of this original alignment attains 40 rmp. Secondly, it was cascade speed mode according to the Haase´s equation, namely 53 rmp, achieved by enlargement of driving shaft diameter. As to winning of required final product 90 % –200 µm, increased speed resulted in the shortening of grinding time from 17.5 to15.7 hour.

  3. Elaboration and implementation of automatized management system of operating mode at La Hague reprocessing plant

    International Nuclear Information System (INIS)

    Charon, S.; Lepine, C.; Dumetz, A.; Nicolet, J.L.

    1986-01-01

    This paper presents the documentation system for operators conducting the new units for fuel reprocessing at La Hague plant. The aim of this system, called COGEMO, is to improve man-machine system reliability, by presenting in real time to operators the information required for efficiently operating the installation in any situation (start up), transients, incidents). Qualification is developed in two shops (a mechanical and a chemical unit) and will be extended to other units when they will be put into service [fr

  4. Technical Note: Continuity of MIPAS-ENVISAT operational ozone data quality from full- to reduced-spectral-resolution operation mode

    Directory of Open Access Journals (Sweden)

    S. Ceccherini

    2008-04-01

    Full Text Available MIPAS (Michelson Interferometer for Passive Atmospheric Sounding is operating on the ENVIronmental SATellite (ENVISAT since March 2002. After two years of nearly continuous limb scanning measurements, at the end of March 2004, the instrument was stopped due to problems with the mirror drive of the interferometer. Operations with reduced maximum path difference, corresponding to both a reduced-spectral-resolution and a shorter measurement time, were resumed on January 2005. In order to exploit the reduction in measurement time, the measurement scenario was changed adopting a finer vertical limb scanning. The change of spectral resolution and of measurement scenario entailed an update of the data processing strategy. The aim of this paper is the assessment of the differences in the quality of the MIPAS ozone data acquired before and after the stop of the operations. Two sets of MIPAS ozone profiles acquired in 2003–2004 (full-resolution measurements and in 2005–2006 (reduced-resolution measurements are compared with collocated ozone profiles obtained by GOMOS (Global Ozone Monitoring by Occultation of Stars, itself also onboard ENVISAT. The continuity of the GOMOS data quality allows to assess a possible discontinuity of the MIPAS performances. The relative bias and precision of MIPAS ozone profiles with respect to the GOMOS ones have been compared for the measurements acquired before and after the stop of the MIPAS operations. The results of the comparison show that, in general, the quality of the MIPAS ozone profiles retrieved from reduced-resolution measurements is comparable or better than that obtained from the full-resolution dataset. The only significant change in MIPAS performances is observed at pressures around 2 unit{hPa}, where the relative bias of the instruments increases by a factor of 2 from the 2003–2004 to 2005–2006 measurements.

  5. Task Analytic Models to Guide Analysis and Design: Use of the Operator Function Model to Represent Pilot-Autoflight System Mode Problems

    Science.gov (United States)

    Degani, Asaf; Mitchell, Christine M.; Chappell, Alan R.; Shafto, Mike (Technical Monitor)

    1995-01-01

    Task-analytic models structure essential information about operator interaction with complex systems, in this case pilot interaction with the autoflight system. Such models serve two purposes: (1) they allow researchers and practitioners to understand pilots' actions; and (2) they provide a compact, computational representation needed to design 'intelligent' aids, e.g., displays, assistants, and training systems. This paper demonstrates the use of the operator function model to trace the process of mode engagements while a pilot is controlling an aircraft via the, autoflight system. The operator function model is a normative and nondeterministic model of how a well-trained, well-motivated operator manages multiple concurrent activities for effective real-time control. For each function, the model links the pilot's actions with the required information. Using the operator function model, this paper describes several mode engagement scenarios. These scenarios were observed and documented during a field study that focused on mode engagements and mode transitions during normal line operations. Data including time, ATC clearances, altitude, system states, and active modes and sub-modes, engagement of modes, were recorded during sixty-six flights. Using these data, seven prototypical mode engagement scenarios were extracted. One scenario details the decision of the crew to disengage a fully automatic mode in favor of a semi-automatic mode, and the consequences of this action. Another describes a mode error involving updating aircraft speed following the engagement of a speed submode. Other scenarios detail mode confusion at various phases of the flight. This analysis uses the operator function model to identify three aspects of mode engagement: (1) the progress of pilot-aircraft-autoflight system interaction; (2) control/display information required to perform mode management activities; and (3) the potential cause(s) of mode confusion. The goal of this paper is twofold

  6. High temperature continuous operation in the HTTR (HP-11). Summary of the test results in the high temperature operation mode

    International Nuclear Information System (INIS)

    Takamatsu, Kuniyoshi; Ueta, Shohei; Sumita, Junya; Goto, Minoru; Nakagawa, Shigeaki; Hamamoto, Shimpei; Tochio, Daisuke

    2010-11-01

    A high temperature (950 degrees C) continuous operation has been performed for 50 days on the HTTR from January to March in 2010, and the potential to supply stable heat of high temperature for hydrogen production for a long time was demonstrated for the first time in the world. JAEA has evaluated the experimental data obtained by this operation and past rated continuous one, and built the database necessary for commercial HTGRs. According to the results, the concentration of FP released from the fuels in the HTTR was a single through triple-digit lower than that in the foreign HTGRs. It became apparent that the fuels used in the HTTR are the best quality in the world. This successful operation could establish technological basis of HTGRs and show potential of nuclear energy as heat source for innovative thermo-chemical-based hydrogen production, emitting greenhouse gases on a 'low-carbon path' for the first time in the world. We have a plan to progress R and D for practical use of hydrogen production system with HTGRs in the future. (author)

  7. Research on a Novel Exciting Method for a Sandwich Transducer Operating in Longitudinal-Bending Hybrid Modes

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    2017-06-01

    Full Text Available A novel exciting method for a sandwich type piezoelectric transducer operating in longitudinal-bending hybrid vibration modes is proposed and discussed, in which the piezoelectric elements for the excitations of the longitudinal and bending vibrations share the same axial location, but correspond to different partitions. Whole-piece type piezoelectric plates with three separated partitions are used, in which the center partitions generate the first longitudinal vibration, while the upper and lower partitions produce the second bending vibration. Detailed comparisons between the proposed exciting method and the traditional one were accomplished by finite element method (FEM calculations, which were further verified by experiments. Compared with the traditional exciting method using independent longitudinal ceramics and bending ceramics, the proposed method achieves higher electromechanical coupling factors and larger vibration amplitudes, especially for the bending vibration mode. This novel exciting method for longitudinal-bending hybrid vibrations has not changed the structural dimensions of the sandwich transducer, but markedly improves the mechanical output ability, which makes it very helpful and meaningful in designing new piezoelectric actuators operated in longitudinal-bending hybrid vibration modes.

  8. LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; R. C. O' Brien; X. Zhang; G. Tao; B. J. Butler

    2011-11-01

    Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.

  9. Compressed modes for variational problems in mathematical physics and compactly supported multiresolution basis for the Laplace operator

    Science.gov (United States)

    Ozolins, Vidvuds; Lai, Rongjie; Caflisch, Russel; Osher, Stanley

    2014-03-01

    We will describe a general formalism for obtaining spatially localized (``sparse'') solutions to a class of problems in mathematical physics, which can be recast as variational optimization problems, such as the important case of Schrödinger's equation in quantum mechanics. Sparsity is achieved by adding an L1 regularization term to the variational principle, which is shown to yield solutions with compact support (``compressed modes''). Linear combinations of these modes approximate the eigenvalue spectrum and eigenfunctions in a systematically improvable manner, and the localization properties of compressed modes make them an attractive choice for use with efficient numerical algorithms that scale linearly with the problem size. In addition, we introduce an L1 regularized variational framework for developing a spatially localized basis, compressed plane waves (CPWs), that spans the eigenspace of a differential operator, for instance, the Laplace operator. Our approach generalizes the concept of plane waves to an orthogonal real-space basis with multiresolution capabilities. Supported by NSF Award DMR-1106024 (VO), DOE Contract No. DE-FG02-05ER25710 (RC) and ONR Grant No. N00014-11-1-719 (SO).

  10. A Closed-Loop Model of Operator Visual Attention, Situation Awareness, and Performance Across Automation Mode Transitions.

    Science.gov (United States)

    Johnson, Aaron W; Duda, Kevin R; Sheridan, Thomas B; Oman, Charles M

    2017-03-01

    This article describes a closed-loop, integrated human-vehicle model designed to help understand the underlying cognitive processes that influenced changes in subject visual attention, mental workload, and situation awareness across control mode transitions in a simulated human-in-the-loop lunar landing experiment. Control mode transitions from autopilot to manual flight may cause total attentional demands to exceed operator capacity. Attentional resources must be reallocated and reprioritized, which can increase the average uncertainty in the operator's estimates of low-priority system states. We define this increase in uncertainty as a reduction in situation awareness. We present a model built upon the optimal control model for state estimation, the crossover model for manual control, and the SEEV (salience, effort, expectancy, value) model for visual attention. We modify the SEEV attention executive to direct visual attention based, in part, on the uncertainty in the operator's estimates of system states. The model was validated using the simulated lunar landing experimental data, demonstrating an average difference in the percentage of attention ≤3.6% for all simulator instruments. The model's predictions of mental workload and situation awareness, measured by task performance and system state uncertainty, also mimicked the experimental data. Our model supports the hypothesis that visual attention is influenced by the uncertainty in system state estimates. Conceptualizing situation awareness around the metric of system state uncertainty is a valuable way for system designers to understand and predict how reallocations in the operator's visual attention during control mode transitions can produce reallocations in situation awareness of certain states.

  11. Determination of rod insertion limits of the AP600'S M-shim bank at low power operating mode

    International Nuclear Information System (INIS)

    Sutondo, Tegas

    2002-01-01

    A series of calculation works had been conducted to determine the AP00's M-shim bank insertion limits during low-power operating mode. This activity was a part of the preliminary studies toward the plan on implementation a Rapid Power Reduction System (RPRS) in AP00's control / operating system, that enable it to operate under low power level (below 50% RTP). The calculations were performed for cycle 1 and equilibrium cycle as function of power levels and the fraction of AO-bank insertion. The results show that the M-shim insertion limits for both cycle 1 and equilibrium cycle were determined based on the limiting conditions at low-burn-up level (BOL), and high burn-up level (EOL) respectively

  12. A square-plate piezoelectric linear motor operating in two orthogonal and isomorphic face-diagonal-bending modes.

    Science.gov (United States)

    Ci, Penghong; Chen, Zhijiang; Liu, Guoxi; Dong, Shuxiang

    2014-01-01

    We report a piezoelectric linear motor made of a single Pb(Zr,Ti)O3 square-plate, which operates in two orthogonal and isomorphic face-diagonal-bending modes to produce precision linear motion. A 15 × 15 × 2 mm prototype was fabricated, and the motor generated a driving force of up to 1.8 N and a speed of 170 mm/s under an applied voltage of 100 Vpp at the resonance frequency of 136.5 kHz. The motor shows such advantages as large driving force under relatively low driving voltage, simple structure, and stable motion because of its isomorphic face-diagonal-bending mode.

  13. Dynamic viscous behavior of magneto-rheological fluid in coupled mode operation

    International Nuclear Information System (INIS)

    Kaluvan, Suresh; Park, JinHyuk; Choi, Seung-Hyun; Kim, Pyunghwa; Choi, Seung-Bok

    2015-01-01

    A new method of measuring the coupled mode viscosity behavior of magneto-rheological (MR) fluid using the resonance concept is proposed. The coupled mode viscosity measurement device is designed as a resonant system using a cantilever beam probing with the rotating shaft mechanism. The ‘C’ shaped iron core of an electromagnetic coil, mounted in a resonating cantilever beam is used as a probing tip. The MR fluid between the probing tip and the rotating shaft mechanism experiences both squeeze and shear force. The vibration induced by the resonating cantilever beam creates only squeeze force on the MR fluid when the shaft is stationary. When the cantilever beam is vibrating at resonance and the shaft is rotating, the MR fluid experiences coupled (shear and squeeze) force. The cantilever beam is vibrated at its resonant frequency using the piezoelectric actuation technique and the resonance is maintained using simple closed loop resonator electronics. The input current to the probing coil is varied to produce a variable magnetic field which causes the viscosity change of the MR fluid. The viscosity change of the MR fluid produces a coupled force, which induces an additional stiffness on the resonating cantilever beam and alters its initial resonant frequency. The shift in resonant frequency due to the change in viscosity of the MR fluid is measured with the help of a resonator electronics circuit and its viscosity is related to the field dependent coupled mode yield stress of the MR fluid. The proposed measurement device is analytically derived and experimentally evaluated. (technical note)

  14. NETWORK-CENTRIC TECHNOLOGIES FOR CONTROL OF THREE-PHASE NETWORK OPERATION MODES

    Directory of Open Access Journals (Sweden)

    Ye. I. Sokol

    2017-06-01

    Full Text Available Purpose. The development of the control system for three-phase network is based on intelligent technologies of network-centric control of heterogeneous objects. The introduction of unmanned aerial vehicles for monitoring of three-phase network increases the efficiency of management. Methodology. The case of decomposition of the instantaneous capacities of the fixed and variable components for 3-wire system. The features of power balance for the different modes of its functioning. It should be noted that symmetric sinusoidal mode is balanced and good, but really unbalanced, if the standard reactive power is not zero. To solve the problem of compensation is sufficient knowledge of the total value of the inactive components of full power (value of the inactive power without detail. The creation of a methodology of measurement and assessment will require knowledge of the magnitudes of each inactive component separately, which leads to the development of a unified approach to the measurement and compensation of inactive components of full power and the development of a generalized theory of power. Results. Procedure for the compensation of the current of zero sequence excludes from circuit the source, as the active component of instantaneous power of zero sequence, and a vector due to a current of zero sequence. This procedure is performed without time delay as it does not require integration. Only a 3–wire system with symmetrical voltage eliminates pulsations and symmetrization of the equivalent conductances of the phases of the task. Under asymmetric voltage, the power is different, its analysis requires the creation of a vector mathematical model of the energy processes of asymmetrical modes of 3–phase systems. Originality. The proposed method extends the basis of the vector method for any zero sequence voltages and shows that the various theories of instantaneous power three wired scheme due to the choice of a basis in a two

  15. Human error mode identification for NPP main control room operations using soft controls

    International Nuclear Information System (INIS)

    Lee, Seung Jun; Kim, Jaewhan; Jang, Seung-Cheol

    2011-01-01

    The operation environment of main control rooms (MCRs) in modern nuclear power plants (NPPs) has considerably changed over the years. Advanced MCRs, which have been designed by adapting digital and computer technologies, have simpler interfaces using large display panels, computerized displays, soft controls, computerized procedure systems, and so on. The actions for the NPP operations are performed using soft controls in advanced MCRs. Soft controls have different features from conventional controls. Operators need to navigate the screens to find indicators and controls and manipulate controls using a mouse, touch screens, and so on. Due to these different interfaces, different human errors should be considered in the human reliability analysis (HRA) for advanced MCRs. In this work, human errors that could occur during operation executions using soft controls were analyzed. This work classified the human errors in soft controls into six types, and the reasons that affect the occurrence of the human errors were also analyzed. (author)

  16. Operator Performance Measurement - Developing Commonality Across Transportation Modes - Proceedings of a September 1994 Workshop

    Science.gov (United States)

    1996-11-01

    This report describes the proceedings of the Workshop on Human Factors Research held in Reston, Virginia. The : objectives of the workshop were to: foster an interchange of experience in measuring and analyzing operator performance : data; encourage ...

  17. Effects of ethanol on combustion and emissions of a gasoline engine operating with different combustion modes

    OpenAIRE

    Ojapah, MM; Zhao, H; Zhang, Y

    2016-01-01

    The introduction of fuel economy and CO2 emission legislations for passenger cars in many countries and regions has spurred the research and development of more efficient gasoline engines. The pumping loss at part-load operations is a major factor for the higher fuel consumption of spark ignition (SI) gasoline engines than the diesel engines. Various approaches have been identified to reduce the pumping loss at part-load operations, leading to improved fuel economy, including Early Intake Val...

  18. Desert Rats 2011 Mission Simulation: Effects of Microgravity Operational Modes on Fields Geology Capabilities

    Science.gov (United States)

    Bleacher, Jacob E.; Hurtado, J. M., Jr.; Meyer, J. A.

    2012-01-01

    Desert Research and Technology Studies (DRATS) is a multi-year series of NASA tests that deploy planetary surface hardware and exercise mission and science operations in difficult conditions to advance human and robotic exploration capabilities. DRATS 2011 (Aug. 30-Sept. 9, 2011) tested strategies for human exploration of microgravity targets such as near-Earth asteroids (NEAs). Here we report the crew perspective on the impact of simulated microgravity operations on our capability to conduct field geology.

  19. On the fast response of charnel electron multipliers in coUnting mode operation

    International Nuclear Information System (INIS)

    Belyaevskij, O.A.; Gladyshev, I.L.; Korobochko, Yu.S.; Mineev, V.I.

    1983-01-01

    Dependences of amplitude distribution of pulses at the outlet of channel electron multipliers (CEM) and effectiveness of monitoring on counting rate at different supply voltages are determined. It is shown that the maximUm counting rate of CEM runs into 6x10 5 s -1 at short-term and 10 5 s -1 at long-term operation using monitoring eqUipment with operation threshold of 2.5 mV

  20. Study on variance-to-mean method as subcriticality monitor for accelerator driven system operated with pulse-mode

    International Nuclear Information System (INIS)

    Yamauchi, Hideto; Kitamura, Yasunori; Yamane, Yoshihiro; Misawa, Tsuyoshi; Unesaki, Hironobu

    2003-01-01

    Two types of the variance-to-mean methods for the subcritical system that was driven by the periodic and pulsed neutron source were developed and their experimental examination was performed with the Kyoto University Critical Assembly and a pulsed neutron generator. As a result, it was demonstrated that the prompt neutron decay constant could be measured by these methods. From this fact, it was concluded that the present variance-to-mean methods had potential for being used in the subcriticality monitor for the future accelerator driven system operated with the pulse-mode. (author)

  1. Self-mode-locking operation of a diode-end-pumped Tm:YAP laser with watt-level output power

    Science.gov (United States)

    Zhang, Su; Zhang, Xinlu; Huang, Jinjer; Wang, Tianhan; Dai, Junfeng; Dong, Guangzong

    2018-03-01

    We report on a high power continuous wave (CW) self-mode-locked Tm:YAP laser pumped by a 792 nm laser diode. Without any additional mode-locking elements in the cavity, stable and self-starting mode-locking operation has been realized. The threshold pump power of the CW self-mode-locked Tm:YAP laser is only 5.4 W. The maximum average output power is as high as 1.65 W at the pump power of 12 W, with the repetition frequency of 468 MHz and the center wavelength of 1943 nm. To the best of our knowledge, this is the first CW self-mode-locked Tm:YAP laser. The experiment results show that the Tm:YAP crystal is a promising gain medium for realizing the high power self-mode-locking operation at 2 µm.

  2. The Influence of Various Operation Modes on Diesel Passenger Cars CO2 Emissions

    Directory of Open Access Journals (Sweden)

    Arina Negoițescu

    2015-07-01

    Full Text Available The amount of emissions released into the atmosphere by polluting sources was significantly reduced due to the limitations introduced by the EU. Since one of the main sources affecting air quality is the car, researches regarding the influence of various factors on exhaust emissions are carried out. As CO2 is the main pollutant responsible for the greenhouse effect, the article treats the influence of vehicle load and traffic levels, running modes, the electric consumer’s utilization, and driving style on CO2 emissions for cars equipped with diesel engine. The results from the conducted study can contribute to adopt solutions in order to decrease the concentration of CO2 emissions from cars equipped with diesel engines.

  3. A safety equipment list for rotary mode core sampling systems operation in single shell flammable gas tanks; TOPICAL

    International Nuclear Information System (INIS)

    SMALLEY, J.L.

    1999-01-01

    This document identifies all interim safety equipment to be used for rotary mode core sampling of single-shell flammable gas tanks utilizing Rotary Mode Core Sampling systems (RMCS). This document provides the safety equipment for RMCS trucks HO-68K-4600, HO-68K-4647, trucks three and four respectively, and associated equipment. It is not intended to replace or supersede WHC-SD-WM-SEL-023, (Kelly 1991), or WHC-SD-WM-SEL-032, (Corbett 1994), which classifies 80-68K-4344 and HO-68K-4345 respectively. The term ''safety equipment'' refers to safety class (SC) and safety significant (SS) equipment, where equipment refers to structures, systems and components (SSC's). The identification of safety equipment in this document is based on the credited design safety features and analysis contained in the Authorization Basis (AB) for rotary mode core sampling operations in single-shell flammable gas tanks. This is an interim safety classification since the AB is interim. This document will be updated to reflect the final RMCS equipment safety classification designations upon completion of a final AB which will be implemented with the release of the Final Safety Analysis Report (FSAR)

  4. A safety equipment list for rotary mode core sampling systems operation in single shell flammable gas tanks

    International Nuclear Information System (INIS)

    SMALLEY, J.L.

    1999-01-01

    This document identifies all interim safety equipment to be used for rotary mode core sampling of single-shell flammable gas tanks utilizing Rotary Mode Core Sampling systems (RMCS). This document provides the safety equipment for RMCS trucks HO-68K-4600, HO-68K-4647, trucks three and four respectively, and associated equipment. It is not intended to replace or supersede WHC-SD-WM-SEL-023, (Kelly 1991), or WHC-SD-WM-SEL-032, (Corbett 1994), which classifies 80-68K-4344 and HO-68K-4345 respectively. The term ''safety equipment'' refers to safety class (SC) and safety significant (SS) equipment, where equipment refers to structures, systems and components (SSC's). The identification of safety equipment in this document is based on the credited design safety features and analysis contained in the Authorization Basis (AB) for rotary mode core sampling operations in single-shell flammable gas tanks. This is an interim safety classification since the AB is interim. This document will be updated to reflect the final RMCS equipment safety classification designations upon completion of a final AB which will be implemented with the release of the Final Safety Analysis Report (FSAR)

  5. On functional determinants of matrix differential operators with multiple zero modes

    NARCIS (Netherlands)

    Falco, G.M.; Fedorenko, Andrey A; Gruzberg, Ilya A

    2017-01-01

    We generalize the method of computing functional determinants with a single excluded zero eigenvalue developed by McKane and Tarlie to differential operators with multiple zero eigenvalues. We derive general formulas for such functional determinants of $r\\times r$ matrix second order differential

  6. COOPERATIVE MODE OF ELECTRIC MOTOR AND INTERNAL COMBUSTION ENGINE OPERATION IN THE CONVERSION HYBRID CAR

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-12-01

    Full Text Available In the given article the authors proposed a method to control the car, which is converted into a hybrid one. The electric motor and combustion engine operate alternately in the car. They proposed a device for implementing this method and a circuit design for the device in question. They also calculated the dynamics of the vehicle under the joint acceleration.

  7. Risk contribution from low power, shutdown, and other operational modes beyond full power

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1995-04-01

    During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

  8. Risk contribution from low power, shutdown, and other operational modes beyond full power

    International Nuclear Information System (INIS)

    Whitehead, D.W.; Brown, T.D.; Chu, T.L.; Pratt, W.T.

    1995-01-01

    During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented

  9. Nonlinear Polarization Rotation-Based Mode-Locked Erbium-Doped Fiber Laser with Three Switchable Operation States

    International Nuclear Information System (INIS)

    Tiu Zian Cheak; Tan Sin Jin; Zarei Arman; Ahmad Harith; Harun Sulaiman Wadi

    2014-01-01

    A simple mode-locked erbium-doped fiber laser (EDFL) with three switchable operation states is proposed and demonstrated based on nonlinear polarization rotation. The EDFL generates a stable square pulse at a third harmonic pulse repetition rate of 87 kHz as the 1480 nm pump power increases from the threshold of 17.5 mW to 34.3 mW. The square pulse duration increases from 105 ns to 245 ns as the pump power increases within this region. The pulse operation switches to the second operation state as the pump power is varied from 48.2 mW to 116.7 mW. The laser operates at a fundamental repetition rate of 29 kHz with a fixed pulse width of 8.5 μs within the pump power region. At a pump power of 116.7 mW, the average output power is 3.84 mW, which corresponds to the pulse energy of 131.5 nJ. When the pump power continues to increase, the pulse train experiences unstable oscillation before it reaches the third stable operation state within a pump power region of 138.9 mW to 145.0 mW. Within this region, the EDFL produces a fixed pulse width of 2.8 μs and a harmonic pulse repetition rate of 58 kHz. (fundamental areas of phenomenology(including applications))

  10. Evaluation of waste temperatures in AWF tanks for bypass mode operation of the 702-AZ ventilation system (Project W-030)

    International Nuclear Information System (INIS)

    Sathyanarayana, K.

    1997-01-01

    This report describes the results of thermal hydraulic analysis performed to provide data in support of Project W-030 to startup new 702-AZ Primary Ventilation System. During the startup of W-030 system, the ventilation system will be operating in bypass mode. In bypass made of operation, the system is capable of supplying 1000 cfm total flow for all four AWF doubleshell tanks. The design of the W-030 system is based on the assumption that both the recirculation loop of the primary ventilation system and the secondary ventilation which provides cooling would be operating. However, during the startup neither the recirculation system nor the secondary ventilation system will be operating. A minimum flow of 100 cfm is required to prevent any flammable gas associated risk. The remaining 600 cfm flow can be divided among the four tanks as necessary to keep the peak sludge temperatures below the operating temperature limit. For the purpose of determining the minimum flow required for cooling each tank, the thermal hydraulic analysis is performed to predict the peak sludge temperatures in AY/AZ tanks under different ventilation flows. The heat load for AZ farm tanks is taken from characterization reports and for the AY farm tanks, the heat load was estimated by thermal analysis using the measured waste temperatures and the waste liquid evaporation rates. The tank 241-AZ-101 and the tank 241-AZ-102 have heat loads of 241,600 and 199,500 Btu/hr respectively. The tank 241-AY-101 and tank 241-AY-102 have heat loads of 41,000 and 33,000 Btu/hr respectively. Using the ambient meteorological conditions of temperature and relative humidity for the air and tank, some soil surface and the sludge levels reported in recent documents, the peak sludge and supernatant temperatures were predicted for various primary ventilation flows ranging from 100 to 400 cfm for AZ tanks and 100 and 150 cfm for AY tanks. The results of these thermal hydraulic analyses are presented. Based on the

  11. Chemical mode control in nuclear power plant decommissioning during operation of technologies in individual radioactive waste processing plants

    International Nuclear Information System (INIS)

    Horvath, J.; Dugovic, L.

    1999-01-01

    Sewage treatment of nuclear power plant decommissioning is performed by system of sewage concentration in evaporator with formation of condensed rest, it means radioactive waste concentrate and breeding steam. During sewage treatment plant operation department of chemical mode performs chemical and radiochemical analysis of sewage set for treatment, chemical and radiochemical analysis of breeding steam condensate which is after final cleaning on ionization filter and fulfilling the limiting conditions released to environment; chemical and radiochemical analysis of heating steam condensate which is also after fulfilling the limiting conditions released to environment. Condensed radioactive concentrate is stored in stainless tanks and later converted into easy transportable and chemically stable matrix from the long term storage point of view in republic storage Mochovce. The article also refer to bituminous plant, vitrification plant, swimming pool decontamination plant of long term storage and operation of waste processing plant Bohunice

  12. Sliding Mode Control for Pressurized-Water Nuclear Reactors in load following operations with bounded xenon oscillations

    International Nuclear Information System (INIS)

    Ansarifar, G.R.; Saadatzi, S.

    2015-01-01

    Highlights: • We present SMC which is a robust nonlinear controller to control the PWR power. • Xenon oscillations are kept bounded within acceptable limits. • The stability analysis has been based on Lyapunov approach. • Simulation results indicate the high performance of this new control. - Abstract: One of the important operations in nuclear power plants is load-following in which imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation considered to be a constraint for the load-following operation. In this paper, sliding mode control (SMC) which is a robust nonlinear controller is designed to control the Pressurized-Water Nuclear Reactor (PWR) power for the load-following operation problem that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to maintain xenon oscillations to be bounded. The constant AO is a robust state constraint for load-following problem. The reactor core is simulated based on the two-point nuclear reactor model and one delayed neutron group. The stability analysis is given by means Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the sliding mode control exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness and stability. Results show that the proposed controller for the load-following operation is sufficiently effective so that the xenon oscillations are kept bounded in the considered region

  13. Operation modes of the FALCON ion source as a part of the AMS cluster tool

    Directory of Open Access Journals (Sweden)

    Girka Oleksii

    2015-06-01

    Full Text Available The paper investigates the options to increase the production yield of temperature compensated surface acoustic wave (SAW devices with a defined range of operational frequencies. The paper focuses on the preparation of large wafers with SiO2 and AlN/Si3N4 depositions. Stability of the intermediate SiO2 layer is achieved by combining high power density UV radiation with annealing in high humidity environment. A uniform thickness of the capping AlN layer is achieved by local high-rate etching with a focused ion beam emitted by the FALCON ion source. Operation parameters and limitations of the etching process are discussed.

  14. Concept and realization of unmanned aerial system with different modes of operation

    Energy Technology Data Exchange (ETDEWEB)

    Czyba, Roman; Szafrański, Grzegorz; Janusz, Wojciech; Niezabitowski, Michał; Czornik, Adam; Błachuta, Marian [Silesian University of Technology, Akademicka 2A, 44-100 Gliwice (Poland)

    2014-12-10

    In this paper we describe the development process of unmanned aerial system, its mechanical components, electronics and software solutions. During the stage of design, we have formulated some necessary requirements for the multirotor vehicle and ground control station in order to build an optimal system which can be used for the reconnaissance missions. Platform is controlled by use of the ground control station (GCS) and has possibility of accomplishing video based observation tasks. In order to fulfill this requirement the on-board payload consists of mechanically stabilized camera augmented with machine vision algorithms to enable object tracking tasks. Novelty of the system are four modes of flight, which give full functionality of the developed UAV system. Designed ground control station is consisted not only of the application itself, but also a built-in dedicated components located inside the chassis, which together creates an advanced UAV system supporting the control and management of the flight. Mechanical part of quadrotor is designed to ensure its robustness while meeting objectives of minimizing weight of the platform. Finally the designed electronics allows for implementation of control and estimation algorithms without the needs for their excessive computational optimization.

  15. Apparent stress-strain relationships in experimental equipment where magnetorheological fluids operate under compression mode

    International Nuclear Information System (INIS)

    Mazlan, S A; Ekreem, N B; Olabi, A G

    2008-01-01

    This paper presents an experimental investigation of two different magnetorheological (MR) fluids, namely, water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite element method magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between two flat surfaces. During the compression, the upper surface was moved towards the lower surface in a vertical direction. Stress-strain relationships were obtained for arrangements of equipment where each type of fluid was involved, using compression test equipment. The apparent compressive stress was found to be increased with the increase in magnetic field strength. In addition, the apparent compressive stress of the water-based MR fluid showed a response to the compressive strain of greater magnitude. However, during the compression process, the hydrocarbon-based MR fluid appeared to show a unique behaviour where an abrupt pressure drop was discovered in a region where the apparent compressive stress would be expected to increase steadily. The conclusion is drawn that the apparent compressive stress of MR fluids is influenced strongly by the nature of the carrier fluid and by the magnitude of the applied current

  16. Analytical expressions for chatter analysis in milling operations with one dominant mode

    Science.gov (United States)

    Iglesias, A.; Munoa, J.; Ciurana, J.; Dombovari, Z.; Stepan, G.

    2016-08-01

    In milling, an accurate prediction of chatter is still one of the most complex problems in the field. The presence of these self-excited vibrations can spoil the surface of the part and can also cause a large reduction in tool life. The stability diagrams provide a practical selection of the optimum cutting conditions determined either by time domain or frequency domain based methods. Applying these methods parametric or parameter traced representations of the linear stability limits can be achieved by solving the corresponding eigenvalue problems. In this work, new analytical formulae are proposed related to the parameter domains of both Hopf and period doubling type stability boundaries emerging in the regenerative mechanical model of time periodical milling processes. These formulae are useful to enrich and speed up the currently used numerical methods. Also, the destabilization mechanism of double period chatter is explained, creating an analogy with the chatter related to the Hopf bifurcation, considering one dominant mode and using concepts established by the Pioneers of chatter research.

  17. Concept and realization of unmanned aerial system with different modes of operation

    International Nuclear Information System (INIS)

    Czyba, Roman; Szafrański, Grzegorz; Janusz, Wojciech; Niezabitowski, Michał; Czornik, Adam; Błachuta, Marian

    2014-01-01

    In this paper we describe the development process of unmanned aerial system, its mechanical components, electronics and software solutions. During the stage of design, we have formulated some necessary requirements for the multirotor vehicle and ground control station in order to build an optimal system which can be used for the reconnaissance missions. Platform is controlled by use of the ground control station (GCS) and has possibility of accomplishing video based observation tasks. In order to fulfill this requirement the on-board payload consists of mechanically stabilized camera augmented with machine vision algorithms to enable object tracking tasks. Novelty of the system are four modes of flight, which give full functionality of the developed UAV system. Designed ground control station is consisted not only of the application itself, but also a built-in dedicated components located inside the chassis, which together creates an advanced UAV system supporting the control and management of the flight. Mechanical part of quadrotor is designed to ensure its robustness while meeting objectives of minimizing weight of the platform. Finally the designed electronics allows for implementation of control and estimation algorithms without the needs for their excessive computational optimization

  18. A comparative experimental study on engine operating on premixed charge compression ignition and compression ignition mode

    Directory of Open Access Journals (Sweden)

    Bhiogade Girish E.

    2017-01-01

    Full Text Available New combustion concepts have been recently developed with the purpose to tackle the problem of high emissions level of traditional direct injection Diesel engines. A good example is the premixed charge compression ignition combustion. A strategy in which early injection is used causing a burning process in which the fuel burns in the premixed condition. In compression ignition engines, soot (particulate matter and NOx emissions are an extremely unsolved issue. Premixed charge compression ignition is one of the most promising solutions that combine the advantages of both spark ignition and compression ignition combustion modes. It gives thermal efficiency close to the compression ignition engines and resolves the associated issues of high NOx and particulate matter, simultaneously. Premixing of air and fuel preparation is the challenging part to achieve premixed charge compression ignition combustion. In the present experimental study a diesel vaporizer is used to achieve premixed charge compression ignition combustion. A vaporized diesel fuel was mixed with the air to form premixed charge and inducted into the cylinder during the intake stroke. Low diesel volatility remains the main obstacle in preparing premixed air-fuel mixture. Exhaust gas re-circulation can be used to control the rate of heat release. The objective of this study is to reduce exhaust emission levels with maintaining thermal efficiency close to compression ignition engine.

  19. Edge operational space for high density/high confinement ELMY H-modes in JET

    International Nuclear Information System (INIS)

    Sartori, R.; Saibene, G.; Loarte, A.

    2002-01-01

    This paper discusses how the proximity to the L-H threshold affects the confinement of ELMy H-modes at high density. The largest reduction in confinement at high density is observed at the transition from the Type I to the Type III ELMy regime. At medium plasma triangularity, δ≅0.3 (where δ is the average triangularity at the separatrix), JET experiments show that by increasing the margin above the L-H threshold power and maintaining the edge temperature above the critical temperature for the transition to Type III ELMs, it is possible to avoid the degradation of the pedestal pressure with density, normally observed at lower power. As a result, the range of achievable densities (both in the core and in the pedestal) is increased. At high power above the L-H threshold power the core density was equal to the Greenwald limit with H97≅0.9. There is evidence that a mixed regime of Type I and Type II ELMs has been obtained at this intermediate triangularity, possibly as a result of this increase in density. At higher triangularity, δ≅0.5, the power required to achieve similar results is lower. (author)

  20. High-power LED light sources for optical measurement systems operated in continuous and overdriven pulsed modes

    Science.gov (United States)

    Stasicki, Bolesław; Schröder, Andreas; Boden, Fritz; Ludwikowski, Krzysztof

    2017-06-01

    The rapid progress of light emitting diode (LED) technology has recently resulted in the availability of high power devices with unprecedented light emission intensities comparable to those of visible laser light sources. On this basis two versatile devices have been developed, constructed and tested. The first one is a high-power, single-LED illuminator equipped with exchangeable projection lenses providing a homogenous light spot of defined diameter. The second device is a multi-LED illuminator array consisting of a number of high-power LEDs, each integrated with a separate collimating lens. These devices can emit R, G, CG, B, UV or white light and can be operated in pulsed or continuous wave (CW) mode. Using an external trigger signal they can be easily synchronized with cameras or other devices. The mode of operation and all parameters can be controlled by software. Various experiments have shown that these devices have become a versatile and competitive alternative to laser and xenon lamp based light sources. The principle, design, achieved performances and application examples are given in this paper.

  1. Efficacy of the fractional photothermolysis system with dynamic operating mode on acne scars and enlarged facial pores.

    Science.gov (United States)

    Cho, Sung Bin; Lee, Ju Hee; Choi, Moon Jung; Lee, Kyu-Yeop; Oh, Sang Ho

    2009-01-01

    Current treatments for acne scars and enlarged facial pores have shown limited efficacy. To evaluate the efficacy and safety of the fractional photothermolysis system (FPS) with dynamic operating mode on acne scars and enlarged pores. Twelve patients with mild to moderate atrophic acne scars and enlarged pores were included in this study. Three sessions of FPS treatment were performed for acne scars and facial pores monthly. Two blinded dermatologists who compared before and after photos based on a quartile grading scale conducted objective clinical assessments of acne scar- and facial pore-treated areas. We took a biopsy immediately after one treatment with the laser from one of the authors to assess the histologic effects of the laser on facial pores. Follow-up results at 4 months after the last treatment revealed that, of the 12 patients, for acne scars, five demonstrated clinical improvements of 51% to 75% and three demonstrated improvements of 76% to 100%, and for facial pores, five demonstrated moderate clinical improvements of 26% to 50% and three demonstrated improvements of 76% to 100%. Side effects, including pain, post-treatment erythema, and edema, were resolved within 1 week. We suggest that the FPS may provide a new treatment algorithm in some cases with acne scars and enlarged pores. Considering the lack of placebo-controlled, split-face design of our study, optimized, prospective studies should be conducted to fully assess the efficacy of FPS with dynamic operating mode.

  2. Operation Mode and Optimum Design of China's Agricultural Modern Logistics System

    OpenAIRE

    Qin, Shi-bo

    2012-01-01

    Using comparative analysis and logical reasoning methods, in combination with traditional logistics theory and practice, and on the basis of objective demand of modern agricultural development for logistics service, we analyze features of logistics function. Besides, we discuss functional elements and service contents of agricultural modern logistics. In addition, we explore innovation model of agricultural modern logistics and systematized operation of supply chain. Finally, it is concluded ...

  3. Method for determining the optimum mode of operation of the chemical water regime in the water-steam-circuit of power plants

    International Nuclear Information System (INIS)

    Sommerfeldt, P.; Reisner, H.; Hartmann, G.; Kulicke, P.

    1988-01-01

    The method aims at increasing the lifetime of secondary coolant circuit components in nuclear power plants through the determination of the optimum mode of operation of the chemical water regime by help of radioisotopes

  4. Passively mode-locked 4.6 and 10.5 GHz quantum dot laser diodes around 1.55 μm with large operating regime

    NARCIS (Netherlands)

    Heck, M.J.R.; Renault, A.; Bente, E.A.J.M.; Oei, Y.S.; Smit, M.K.; Eikema, K.S.E.; Ubachs, W.; Anantathanasarn, S.; Nötzel, R.

    2009-01-01

    Passive mode-locking in two-section InAs/InP quantum dot laser diodes operating at wavelengths around 1.55 µm is reported. For a 4.6-GHz laser, a large operating regime of stable mode-locking, with RF-peak heights of over 40 dB, is found for injection currents of 750 mA up to 1.0 A and for values of

  5. MODELING OF OPERATION MODES OF SHIP POWER PLANT OF COMBINED PROPULSION COMPLEX WITH CONTROL SYSTEM BASED ON ELECTRONIC CONTROLLERS

    Directory of Open Access Journals (Sweden)

    E. A. Yushkov

    2016-12-01

    Full Text Available Purpose. Designing of diagrams to optimize mathematic model of the ship power plant (SPP combined propulsion complexes (CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. Methodology. After analyzing of ship power plant modes of CPC proposed diagrams to optimize mathematic model of the above mentioned complex. The model based on using of electronic controllers in automatic regulation and control systems for diesel and thruster which allow to actualize more complicated control algorithm with viewpoint of increasing working efficiency of ship power plant at normal and emergency modes. Results. Determined suitability of comparative computer modeling in MatLab Simulink for building of imitation model objects based on it block diagrams and mathematic descriptions. Actualized diagrams to optimize mathematic model of the ship’s power plant (SPP combined propulsion complexes (CPC with Azipod system in MatLab Simulink software package Ships_CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. The function blocks of proposed complex are the main structural units which allow to investigate it normal and emergency modes. Originality. This model represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». For example, the function boxes outputs of PID-regulators of MRDG depends from set excitation voltage and rotating frequency that in turn depends from power-station load and respond that is a ship moving or dynamically positioning, and come on input (inputs of thruster rotating frequency PID-regulator models. Practical value. The results of researches planned to use in

  6. Experimental investigation of non-condensable gases effect on operation of VVER steam generator in condensation mode

    International Nuclear Information System (INIS)

    Efanov, A. D.; Kalyakin, S. G.; Morozov, A. V.; Remizov, O. V.; Tsyganok, A. A.; Generalov, V. N.; Berkovich, V. M.; Taranov, G. S.

    2008-01-01

    To provide the safety in new Russian NPP designs, protection passive systems which don't depend upon human errors are widely used. In terms of safety, the design of NPP of new generation (NPP-2006) falls into the class of advanced NPPs. In the event of an beyond design basis accident with the rupture of the reactor primary circuit and accompanied by the loss of ac sources, the use of passive safety systems are provided for necessary core cooling. Among these is passive heat removal system (PHRS). In the case of leakage in the primary circuit this system ensures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam coming to SG piping from the reactor. As a result, the condensate from steam generators arrives at the core providing its additional cooling. The SG condensation capacity can be adversely affected by the presence of non-condensable gases in the primary circuit of the reactor. Their main sources are nitrogen arriving at the circuit, as hydro accumulators actuate, products of radiolysis of water and air drawn in from the containment through the pipeline rupture. The accumulation of non-condensable gases in SG piping can result in degradation of its condensation capacity to the extent that condensation completely terminates. In this case, the core cooling conditions may be impaired. To experimental investigation of the condensation mode of operation of WER steam generator, a large scale HA2M-SG test rig was constructed at the SSC RF IPPE. The test rig incorporates: buffer tank, equipped by steam supply system; SG model with volumetric-power scale is 1:46; PHRS heat exchanger imitator, cooling by process water. The rig main equipment connected by pipelines and equipped by valves. The elevations of the main equipment correspond to those of reactor project. The rig maximum operating parameters: steam pressure - 1.6 MPa, temperature - 200 Celsius degrees. Experiments at the HA2M-SG test rig have been

  7. New mode of operating a magnetized coaxial plasma gun for injecting magnetic helicity into a spheromak

    International Nuclear Information System (INIS)

    Woodruff, S.; Hill, D.N.; Stallard, B.W.; Bulmer, R.; Cohen, B.; Holcomb, C.T.; Hooper, E.B.; McLean, H.S.; Moller, J.; Wood, R.D.

    2003-01-01

    By operating a magnetized coaxial plasma gun continuously with just sufficient current to enable plasma ejection, large gun-voltage spikes (∼1 kV) are produced, giving the highest sustained voltage ∼500 V and highest sustained helicity injection rate observed in the Sustained Spheromak Physics Experiment. The spheromak magnetic field increases monotonically with time, exhibiting the lowest fluctuation levels observed during formation of any spheromak (B-tilde)/B≥2%). The results suggest an important mechanism for field generation by helicity injection, namely, the merging of helicity-carrying filaments

  8. New mode of operating a magnetized coaxial plasma gun for injecting magnetic helicity into a spheromak.

    Science.gov (United States)

    Woodruff, S; Hill, D N; Stallard, B W; Bulmer, R; Cohen, B; Holcomb, C T; Hooper, E B; McLean, H S; Moller, J; Wood, R D

    2003-03-07

    By operating a magnetized coaxial plasma gun continuously with just sufficient current to enable plasma ejection, large gun-voltage spikes (approximately 1 kV) are produced, giving the highest sustained voltage approximately 500 V and highest sustained helicity injection rate observed in the Sustained Spheromak Physics Experiment. The spheromak magnetic field increases monotonically with time, exhibiting the lowest fluctuation levels observed during formation of any spheromak (B/B>/=2%). The results suggest an important mechanism for field generation by helicity injection, namely, the merging of helicity-carrying filaments.

  9. Design considerations in achieving 1 MW CW operation with a whispering-gallery-mode gyrotron

    International Nuclear Information System (INIS)

    Felch, K.; Feinstein, J.; Hess, C.; Huey, H.; Jongewaard, E.; Jory, H.; Neilson, J.; Pendleton, R.; Pirkle, D.; Zitelli, L.

    1989-09-01

    Varian is developing high-power, CW gyrotrons at frequencies in the range 100 GHz to 150 GHz, for use in electron cyclotron heating applications. Early test vehicles have utilized a TE 15,2,1 interaction cavity, have achieved short-pulse power levels of 820 kW and average power levels of 80 kW at 140 GHz. Present tests are aimed at reaching 400 kW under CW operating conditions and up to 1 MW for short pulse durations. Work is also underway on modifications to the present design that will enable power levels of up to 1 MW CW to be achieved. 7 refs., 2 figs

  10. Metal Pollution Around an Iron Smelter Complex in Northern Norway at Different Modes of Operation

    CERN Document Server

    Steinnes, E; Eidhammer-Sjobakk, T; Varskog, P

    2003-01-01

    The moss biomonitoring technique was employed to study the atmospheric deposition in and around the town of Mo i Rana, northern Norway, before and after closing an iron smelter and establishing alternative ferrous metal industries. Samples of Hylocomium splendens were collected from the same sites in 1989 and 1993. A combination of instrumental neutron activation analysis (INAA) and atomic absorption spectrometry was used to obtain data for 38 elements in these moss samples, and the analytical data were subjected to factor analysis. In general, the deposition was higher when the iron smelter was still in operation, in particular for Fe and for many elements normally associated with crustal matter. For Cr there was a substantially increased deposition due to the operation of a new ferrochrome smelter. Also for Ni and Au an increased deposition was observed, whereas for metals such as Mn, Co, Ag, Sb, and W there was no appreciable change. INAA proved to be a powerful tool for this kind of study. The regional di...

  11. Metal pollution around an iron smelter complex in northern Norway at different modes of operation

    International Nuclear Information System (INIS)

    Steinnes, E.; Sjoebakk, T.E.; Frontas'eva, M.V.; Varskog, P.

    2003-01-01

    The moss biomonitoring technique was employed to study the atmospheric deposition in and around the town of Mo i Rana, northern Norway, before and after closing an iron smelter and establishing alternative ferrous metal industries. Samples of Hylocomium splendens were collected from the same sites in 1989 and 1993. A combination of instrumental neutron activation analysis (INAA) and atomic absorption spectrometry was used to obtain data for 38 elements in these moss samples, and the analytical data were subjected to factor analysis. In general, the deposition was higher when the iron smelter was still in operation, in particular for Fe and for many elements normally associated with crustal matter. For Cr there was a substantially increased deposition due to the operation of a new ferrochrome smelter. Also for Ni and Au an increased deposition was observed, whereas for metals such as Mn, Co, Ag, Sb, and W there was no appreciable change. INAA proved to be a powerful tool for this kind of study. The regional distribution of pollutants was strongly dependent on the local topography. Samples of natural surface soils collected simultaneously with the first moss series showed clear signs of contamination with a number of metals from atmospheric deposition. The approach described in this work could be advantageously used to study atmospheric deposition of heavy metals around iron smelters in Russia and elsewhere

  12. Predictive study on high performance modes of operation in HL-2A

    International Nuclear Information System (INIS)

    Gao Qingdi; Li Fangzhu; Zhang Jinhua; Qu Hongpeng; Budny, R.V.

    2003-01-01

    High performance scenarios in the HL-2A tokamak are studied by numerical modeling. Through shifting the plasma column outwards a shaping plasma with significant triangularity is achieved with sufficient room left for the RF antenna. For the out-shifted shaping plasma, ripple loss of high energy ions during NBI is analyzed. The results show that the ripple loss fraction of NBI power for the shaping plasma is not higher than that for the unshifted circular plasma. The time dependent TRANSP code is used to model realistic reversed magnetic shear operation in HL-2A. In order to sustain the RS operation towards steady-state, off-axis current drive with a lower hybrid wave at 2.45GHz is used to control the current profile. A steady-state RS discharge is formed and sustained until the LH power is turned off; the plasma confinement is enhanced with the development of an internal transport barrier. In the RS discharges with shaping plasma geometry a double transport barrier is produced. (author)

  13. Implementing batteries in electrical grids. Possible operating modes for efficient business cases

    Energy Technology Data Exchange (ETDEWEB)

    Kittlaus, Barnabas; Schreider, Achim; Pour, Adel Hassan [Lahmeyer International GmbH, Bad Vilbel (Germany)

    2010-07-01

    For almost two decades, there has been a global trend towards the deregulation and the liberalisation of electricity markets. Previously, national or regional monopolistic utility companies provided services along the entire supply chain of electricity supply: Beginning with the operation of power plants and thus the generation of electricity, continuing through the development and the operation of transmission and local distribution grids, to the connection points. Since all assets belonged to the utility company, they could easily access generation units in order to provide balancing power for the safe and reliable operation of the electricity networks. With the objective of a more efficient and cheaper electricity supply by enabling competition, European Directive 96/92/EC (repealed by 2003/53/EC) enacted so-called ''unbundling'' which meant the break-up of utility companies as full service suppliers into the three service oriented entities; for electricity generation, transmission and supply. Whereas previously a single utility company provided the balancing of the electricity grid with its own assets, as a consequence of the directive, markets developed for the provision of diverse technical services. As long as the utility companies provided these services on their own, technical rather than economic aspects prevailed in their investment decisions. With the establishment of open markets for primary, secondary and tertiary reserve power, commercial interfaces had been established which force the respective specialised market actor to investment decisions driven primarily by economic aspects. At nearly the same time - around two decades ago, the first renewable energy systems (RES) provided electricity to public grids. In the 1990's their share of the overall electricity mix was negligible, but since the beginning of the new millennium more and more countries recognised the ecological and economic advantages of RES and established incentive systems for their

  14. Heavy impurity confinement in hybrid operation scenario plasmas with a rotating 1/1 continuous mode

    Science.gov (United States)

    Raghunathan, M.; Graves, J. P.; Nicolas, T.; Cooper, W. A.; Garbet, X.; Pfefferlé, D.

    2017-12-01

    In future tokamaks like ITER with tungsten walls, it is imperative to control tungsten accumulation in the core of operational plasmas, especially since tungsten accumulation can lead to radiative collapse and disruption. We investigate the behavior of tungsten trace impurities in a JET-like hybrid scenario with both axisymmetric and saturated 1/1 ideal helical core in the presence of strong plasma rotation. For this purpose, we obtain the equilibria from VMEC and use VENUS-LEVIS, a guiding-center orbit-following code, to follow heavy impurity particles. In this work, VENUS-LEVIS has been modified to account for strong plasma flows with associated neoclassical effects arising from such flows. We find that the combination of helical core and plasma rotation augments the standard neoclassical inward pinch compared to axisymmetry, and leads to a strong inward pinch of impurities towards the magnetic axis despite the strong outward diffusion provided by the centrifugal force, as frequently observed in experiments.

  15. Different Modes of Monitoring and Correction of Cardiac Function During Operations Under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    L. A. Krichevsky

    2007-01-01

    Full Text Available Objective: to comparatively evaluate the efficiency of intensive care measures chosen on the basis of traditional monitoring of central hemodynamics (CH or on that of the data of transesophageal echocardiography (TE echoCG.Materials and methods: 50 patients were examined at coronary bypass surgery under extracorporeal circulation. Under a prospective comparative analysis were two algorithms of treatment policy: maintenance of cardiac index, by using the maximum volemic load, or that of left ventricular systolic function under guidance of transesophageal echocardiography.Results: Significantly (p<0.05 larger doses of dopamine and/or dobutamine were required to maintain adequate left ventricular systolic function. However, this treatment policy showed much better (p<0.05 circulatory parameters in the postperfusion period. At the same time the duration of postoperative inotropic therapy in these patients proved to be significantly (p<0.05 less.Conclusion. The treatment policy based on the maintenance of left ventricular systolic function under guidance of TE echoCG leads to the shortest circulatory stabilization during myocardial revascularization. The application of a volemic load and the expectant use of inotropic drugs result in a longer restoration of operated heart function. 

  16. Mode of operation and performance of a simulation model for the electricity management

    International Nuclear Information System (INIS)

    Weible, H.

    1981-01-01

    In the first two main parts of this report the structure of a simulation model to define the consequences of decisions in the electricity supply sector is explained, based on a careful revision of relevant problems. By means of the system analysis the model represents an attempt to describe all essential relations between the electricity demand on the one hand and the consequences of the generation of electricity (indluding transport) for consumers, state, environment, market of capital and fuel on the other hand. The multifarious ways of operation and application of the model are demonstrated taking the public electricity management of Baden-Wuerttemberg as an example. Besides a validation of the model for 1970 to 1977, possible trends until the year 2000 are shown. As an essential result of the analyses it can be shown, that a renunciation on the further extension of nuclear energy turns out to be unrealistic by a supposed average increase of the electricity demand of 4% p.a.. A comparison of different model conceptions shows, that the information loss, which proceeds from the approximation of year-load-curves, leads to important deviations in the model results. According to the sensitivity analyses the increase of the electricity consumption turns out to be the most essential influence on the time dependent results. (orig./UA) [de

  17. Model for Sucker-Rod Pumping Unit Operating Modes Analysis Based on SimMechanics Library

    Science.gov (United States)

    Zyuzev, A. M.; Bubnov, M. V.

    2018-01-01

    The article provides basic information about the process of a sucker-rod pumping unit (SRPU) model developing by means of SimMechanics library in the MATLAB Simulink environment. The model is designed for the development of a pump productivity optimal management algorithms, sensorless diagnostics of the plunger pump and pumpjack, acquisition of the dynamometer card and determination of a dynamic fluid level in the well, normalization of the faulty unit operation before troubleshooting is performed by staff as well as equilibrium ratio determining by energy indicators and outputting of manual balancing recommendations to achieve optimal power consumption efficiency. Particular attention is given to the application of various blocks from SimMechanics library to take into account the pumpjack construction principal characteristic and to obtain an adequate model. The article explains in depth the developed tools features for collecting and analysis of simulated mechanism data. The conclusions were drawn about practical implementation possibility of the SRPU modelling results and areas for further development of investigation.

  18. Numerical simulation of hydrodynamics in a pump-turbine at off-design operating conditions in turbine mode

    International Nuclear Information System (INIS)

    Yan, J P; Seidel, U; Koutnik, J

    2012-01-01

    The hydrodynamics of a reduced-scaled model of a radial pump-turbine is investigated under off-design operating conditions, involving runaway and 'S-shape' turbine brake curve at low positive discharge. It is a low specific speed pump-turbine machine of Francis type with 9 impeller blades and 20 stay vanes as well as 20 guide vanes. The computational domain includes the entire water passage from the spiral casing inlet to the draft tube outlet. Completely structured hexahedral meshes generated by the commercial software ANSYS-ICEM are employed. The unsteady incompressible simulations are performed using the commercial code ANSYS-CFX13. For turbulence modeling the standard k-ε model is applied. The numerical results at different operating points are compared to the experimental results. The predicted pressure amplitude is in good agreement with the experimental data and the amplitude of normal force on impeller is in reasonable range. The detailed analysis reveals the onset of the flow instabilities when the machine is brought from a regular operating condition to runaway and turbine break mode. Furthermore, the rotating stall phenomena are well captured at runaway condition as well as low discharge operating condition with one stall cell rotating inside and around the impeller with about 70% of its frequency. Moreover, the rotating stall is found to be the effect of rotating flow separations developed in several consecutive impeller channels which lead to their blockage. The reliable simulation of S-curve characteristics in pump-turbines is a basic requirement for design and optimization at off-design operating conditions.

  19. Long-term meditation training induced changes in the operational synchrony of default mode network modules during a resting state.

    Science.gov (United States)

    Fingelkurts, Andrew A; Fingelkurts, Alexander A; Kallio-Tamminen, Tarja

    2016-02-01

    Using theoretical analysis of self-consciousness concept and experimental evidence on the brain default mode network (DMN) that constitutes the neural signature of self-referential processes, we hypothesized that the anterior and posterior subnets comprising the DMN should show differences in their integrity as a function of meditation training. Functional connectivity within DMN and its subnets (measured by operational synchrony) has been measured in ten novice meditators using an electroencephalogram (EEG) recording in a pre-/post-meditation intervention design. We have found that while the whole DMN was clearly suppressed, different subnets of DMN responded differently after 4 months of meditation training: The strength of EEG operational synchrony in the right and left posterior modules of the DMN decreased in resting post-meditation condition compared to a pre-meditation condition, whereas the frontal DMN module on the contrary exhibited an increase in the strength of EEG operational synchrony. These findings combined with published data on functional-anatomic heterogeneity within the DMN and on trait subjective experiences commonly found following meditation allow us to propose that the first-person perspective and the sense of agency (the witnessing observer) are presented by the frontal DMN module, while the posterior modules of the DMN are generally responsible for the experience of the continuity of 'I' as embodied and localized within bodily space. Significance of these findings is discussed.

  20. Experimental evidence for the suitability of ELMing H-mode operation in ITER with regard to core transport of helium

    International Nuclear Information System (INIS)

    Wade, M.R.; Hillis, D.L.; Burrell, K.H.

    1996-09-01

    Studies have been conducted in DIII-D to assess the viability of the ITER design with regard to helium ash removal, including both global helium exhaust studies and detailed helium transport studies. With respect to helium ash accumulation, the results are encouraging for successful operation of ITER in ELMing H-mode plasmas with conventional high-recycling divertor operation. Helium can be removed from the plasma core with a characteristic time constant of ∼ 8 energy confinement times, even with a central source of helium. Furthermore, the exhaust rate is limited by the pumping efficiency of the system and not by transport of helium within the plasma core. Helium transport studies have shown that D He /X eff ∼ 1 in all confinement regimes studied to date and there is little dependence of D He /X eff on normalized gyroradius in dimensionless scaling studies, suggesting that D He /X eff will be ∼ 1 in ITER. These observations suggest that helium transport within the plasma core should be sufficient to prevent unacceptable fuel dilution in ITER. However, helium exhaust is also strongly dependent on many factors (e.g., divertor plasma conditions, plasma and baffling geometry, flux amplification, pumping speed, etc.) that are difficult to extrapolate. Studies have revealed the helium diffusivity decreases as the plasma density increases, which is unfavorable to ITER's extremely high density operation

  1. A comparison of process performance during the anaerobic mono- and co-digestion of slaughterhouse waste through different operational modes.

    Science.gov (United States)

    Pagés-Díaz, Jhosané; Pereda-Reyes, Ileana; Sanz, Jose Luis; Lundin, Magnus; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

    2018-02-01

    The use of consecutive feeding was applied to investigate the response of the microbial biomass to a second addition of substrates in terms of biodegradation using batch tests as a promising alternative to predict the behavior of the process. Anaerobic digestion (AD) of the slaughterhouse waste (SB) and its co-digestion with manure (M), various crops (VC), and municipal solid waste were evaluated. The results were then correlated to previous findings obtained by the authors for similar mixtures in batch and semi-continuous operation modes. AD of the SB failed showing total inhibition after a second feeding. Co-digestion of the SB+M showed a significant improvement for all of the response variables investigated after the second feeding, while co-digestion of the SB+VC resulted in a decline in all of these response variables. Similar patterns were previously detected, during both the batch and the semi-continuous modes. Copyright © 2017. Published by Elsevier B.V.

  2. Segmentation of a Vibro-Shock Cantilever-Type Piezoelectric Energy Harvester Operating in Higher Transverse Vibration Modes

    Directory of Open Access Journals (Sweden)

    Darius Zizys

    2015-12-01

    Full Text Available The piezoelectric transduction mechanism is a common vibration-to-electric energy harvesting approach. Piezoelectric energy harvesters are typically mounted on a vibrating host structure, whereby alternating voltage output is generated by a dynamic strain field. A design target in this case is to match the natural frequency of the harvester to the ambient excitation frequency for the device to operate in resonance mode, thus significantly increasing vibration amplitudes and, as a result, energy output. Other fundamental vibration modes have strain nodes, where the dynamic strain field changes sign in the direction of the cantilever length. The paper reports on a dimensionless numerical transient analysis of a cantilever of a constant cross-section and an optimally-shaped cantilever with the objective to accurately predict the position of a strain node. Total effective strain produced by both cantilevers segmented at the strain node is calculated via transient analysis and compared to the strain output produced by the cantilevers segmented at strain nodes obtained from modal analysis, demonstrating a 7% increase in energy output. Theoretical results were experimentally verified by using open-circuit voltage values measured for the cantilevers segmented at optimal and suboptimal segmentation lines.

  3. Pulse oximeter using a gain-modulated avalanche photodiode operated in a pseudo lock-in light detection mode

    Science.gov (United States)

    Miyata, Tsuyoshi; Iwata, Tetsuo; Araki, Tsutomu

    2006-01-01

    We propose a reflection-type pulse oximeter, which employs two pairs of a light-emitting diode (LED) and a gated avalanche photodiode (APD). One LED is a red one with an emission wavelength λ = 635 nm and the other is a near-infrared one with that λ = 945 nm, which are both driven with a pulse mode at a frequency f (=10 kHz). Superposition of a transistor-transistor-logic (TTL) gate pulse on a direct-current (dc) bias, which is set so as not exceeding the breakdown voltage of each APD, makes the APD work in a gain-enhanced operation mode. Each APD is gated at a frequency 2f (=20 kHz) and its output signal is fed into a laboratory-made lock-in amplifier that works in synchronous with the pulse modulation signal of each LED at a frequency f (=10 kHz). A combination of the gated APD and the lock-in like signal detection scheme is useful for the reflection-type pulse oximeter thanks to the capability of detecting a weak signal against a large background (BG) light.

  4. STUDY OF TRANSIENT AND STATIONARY OPERATION MODES OF SYNCHRONOUS SYSTEM CONSISTING IN TWO MACHINES

    Directory of Open Access Journals (Sweden)

    V. S. Safaryan

    2017-01-01

    Full Text Available The solution of the problem of reliable functioning of an electric power system (EPS in steady-state and transient regimes, prevention of EPS transition into asynchronous regime, maintenance and restoration of stability of post-emergency processes is based on formation and realization of mathematical models of an EPS processes. During the functioning of electric power system in asynchronous regime, besides the main frequencies, the currents and voltages include harmonic components, the frequencies of which are multiple of the difference of main frequencies. At the two-frequency asynchronous regime the electric power system is being made equivalent in a form of a two-machine system, functioning for a generalized load. In the article mathematical models of transient process of a two-machine system in natural form and in d–q coordinate system are presented. The mathematical model of two-machine system is considered in case of two windings of excitement at the rotors. Also, in the article varieties of mathematical models of EPS transient regimes (trivial, simple, complete are presented. Transient process of a synchronous two-machine system is described by the complete model. The quality of transient processes of a synchronous machine depends on the number of rotor excitation windings. When there are two excitation windings on the rotor (dual system of excitation, the mathematical model of electromagnetic transient processes of a synchronous machine is represented in a complex form, i.e. in coordinate system d, q, the current of rotor being represented by a generalized vector. In asynchronous operation of a synchronous two-machine system with two excitation windings on the rotor the current and voltage systems include only harmonics of two frequencies. The mathematical model of synchronous steady-state process of a two-machine system is also provided, and the steady-state regimes with different structures of initial information are considered.

  5. Operative modes of the primary circuit degasser of Atucha II N.P.P

    International Nuclear Information System (INIS)

    Rodriguez, Ivanna; Contino, Maximiliano; Chocron, Mauricio; Duca, Jorge

    2012-09-01

    Atucha II (N.A.S.A., Buenos Aires Province, Argentina) is a Pressurized Vessel Heavy Water Reactor designed by Siemens with a capacity of 740 MWe. After a long delay in construction the plant is close to the commissioning and among the many task that are carried out, chemistry and operation of devices related to it are under consideration [1]. As it is known, Hydrogen or Deuterium dosing has the purpose of both: limitation of the water radiolysis and to provide an appropriate reductive media for the structural materials, mainly stainless steel, A800 and Zr-4. Dealing with a heavy water plant, it is critical to determine whether it is necessary to add D 2 or if it is feasible to dose H 2 , by considering heavy water degradation and heavy water upgrading system capability. Those aspects have been previously analyzed and presented [2]. It is also necessary to consider blankets and venting locations that address to losses of the expensive D 2 . In the present work several alternatives of hydrogenation are presented and evaluated, considering the Degasser (D), the Volume Control Tank (TCV) and the special features of the purification and volume control system of a pressurized vessel heavy water plant where the primary circuit and moderator are partially mixed. Also the influence of venting through the pressurizer is analyzed. Conclusions are obtained in connection to (i) the maintenance of a permanent blanket of H 2 /He, 4%, in the TCV dome at a given initial pressure, (ii) The same but constant pressure to reach 0.6 ppm of H 2 in the Primary and Moderator water circuit, (iii) transients while reducing pressure in the Degasser and considering contribution of pressurizer venting, (iv) estimated contribution of the general corrosion of the system and (iv) differences if D 2 is used. (authors)

  6. Deformations and Displacements of the LHC Superconducting Dipoles Induced by Standard and Non-Standard Operational Modes

    CERN Document Server

    La China, M; Gubello, G; Scandale, Walter

    2004-01-01

    A full-scale and fully-instrumented working model of the LHC lattice cell has been tested at CERN between March and December 2002. Aside of the current, pressure and temperature sensors, controlled by an industrial supervision system, a novel device has been set to monitor magnet positions with respect to the surrounding cryostat. The series of operating modes to test cryogenics, current leads and quench recovery electronics offered the chance to investigate potentially harmful deformations of the superconducting structure. In this paper we present a survey of displacements and deformations experienced by the LHC cell magnets during thermal cycles, current ramps and resistive transitions. Although the system complexity prevented from complete modeling, a preliminary phenomena explanation is given.

  7. Development and Operation of Dual-Mode Analyzers for Wireless Power Consortium/Power Matters Alliance Wireless Power Systems.

    Science.gov (United States)

    Um, Keehong

    2016-05-01

    We have designed a protocol analyzer to be used in wireless power systems and analyzed the operation of wireless chargers defined by standards of Qi of Wireless Power Consortium (WPC) and Power Matters Alliance (PMA) protocols. The integrated circuit (IC, or microchip) developed so far for wireless power transmission is not easily adopted by chargers for specific purposes. A device for measuring the performance of test equipment currently available is required to transform and expand the types of protocol. Since a protocol analyzer with these functions is required, we have developed a device that can analyze the two protocols of WPC and PMA at the same time. As a result of our research, we present a dual-mode system that can analyze the protocols of both WPC and PMA.

  8. A control approach for the operation of DG units under variations of interfacing impedance in grid-connected mode

    DEFF Research Database (Denmark)

    Hoseini, S. Kazem; Pouresmaeil, E.; Hosseinnia, S. H.

    2016-01-01

    . However, the converter-based DG interface is subjected to the unexpected uncertainties, which highly influence performance of control loop of DG unit and operation of interfaced converter. The interfacing impedance seen by interfaced VSC may considerably vary in power grid, and the stability of interfaced...... converter is highly sensitive to the impacts of this impedance changes; then, DG unit cannot inject appropriate currents. To deal with the instability problem, a control method based on fractional order active sliding mode is proposed in this paper, which is less sensitive to variations of interfacing...... impedance. A fractional sliding surface, which demonstrates the desired dynamics of system is developed and then, the controller is designed in two phases as sliding and reaching phases to keep the control loop stable. Stability issues of the control method are discussed in details and the conditions...

  9. Experimental study of pistachio drying behavior in a mixed-mode PV operated forced convection solar dryer

    Energy Technology Data Exchange (ETDEWEB)

    Zangiabadi, B [Univ. of Stavanger, Stavanger (Norway); Ameri, M; Mahmoudabadi, M M [Shahid Bahonar Univ., Kerman (Iran, Islamic Republic of)

    2008-07-01

    According to FAO statistics, Iran is the largest exporter of pistachios. Kerman province -south east of Iran- has approximately 200000 hectares of pistachio orchards, which provides practically 80% of whole country production of pistachios. After harvesting the pistachio, nuts must be washed to prevent staining. Therefore the nuts have almost 40% moisture content and it must be decreased to storage moisture of 6% or below. Simply decreasing in the moisture content of the products is called drying. In some areas where the environment conditions meet the minimum standard, solar drying can be an alternative approach for drying agricultural products. This work deals with the design, construction and testing a mixed-mode forced convection PV operated solar dryer. (orig.)

  10. Degradation kinetics of reactive dye by UV/H2O2/US process under continuous mode operation.

    Science.gov (United States)

    Fung, P C; Poon, C S; Chu, C W; Tsui, S M

    2001-01-01

    Degradation of a dye, C. I . Reactive Red 120, in dyeing waatewater by the process o UV/H2O2/US was studied with a bench-scale reactor under the continuous mode of operation. The effects of dyeing wastewater flow rate and the feeding rate of an oxidant, H2O2, on the color removal efficiency of the process were investigated. The significance of ultrasonic (US) combined with UV irradiation was also investigated and the performances of the process on color removal were evaluated. The results showed that the decoloration process followed a pseudo first-order kinetic model and the UV light is the most significant factor on dye removal. Besides, at higher flow rates, incomplete color removal was observed due to relatively insufficient irradiation time (low degradation rate). In order to achieve a higher degradation rate, the feeding rate of H2O2 should be increased.

  11. Enhancement mode operation in AlInN/GaN (MIS)HEMTs on Si substrates using a fluorine implant

    International Nuclear Information System (INIS)

    Zaidi, Z H; Lee, K B; Qian, H; Jiang, S; Houston, P A; Guiney, I; Wallis, D J; Humphreys, C J

    2015-01-01

    We have demonstrated enhancement mode operation of AlInN/GaN (MIS)HEMTs on Si substrates using the fluorine treatment technique. The plasma RF power and treatment time was optimized to prevent the penetration of the fluorine into the channel region to maintain high channel conductivity and transconductance. An analysis of the threshold voltage was carried out which defined the requirement for the fluorine sheet concentration to exceed the charge at the dielectric/AlInN interface to achieve an increase in the positive threshold voltage after deposition of the dielectric. This illustrates the importance of control of both the plasma conditions and the interfacial charge for a reproducible threshold voltage. A positive threshold voltage of +3 V was achieved with a maximum drain current of 367 mA mm −1 at a forward gate bias of 10 V. (paper)

  12. The effect of pH and operation mode for COD removal of slaughterhouse wastewater with Anaerobic Batch Reactor (ABR

    Directory of Open Access Journals (Sweden)

    Maria Octoviane Dyan

    2015-01-01

    Full Text Available Disposal of industrial wastes in large quantities was not in accordance with today's standards of waste into environmental issues that must be overcome with proper treatment. Similarly, the abattoir wastewater that contains too high organic compounds and suspended solids. The amount of liquid waste disposal Slaughterhouse (SW with high volume also causes pollution. The research aim to resolve this problem by lowering the levels of BOD-COD to comply with effluent quality standard. Anaerobic process is the right process for slaughterhouse wastewater treatment because of high content of organic compounds that can be utilized by anaerobic bacteria as a growth medium. Some research has been conducted among abattoir wastewater treatment using anaerobic reactors such as ABR, UASB and ASBR. Our research focuses on the search for the optimum results decline effluent COD levels to match the quality standards limbah and cow rumen fluid with biodigester ABR (Anaerobic Batch Reactor. The variables used were PH of 6, 7, and 8, as well as the concentration ratio of COD: N is 400:7; 450:7, and 500:7. COD value is set by the addition of N derived from urea [CO(NH2 2]. COD levels will be measured daily by water displacement technique. The research’s result for 20 days seen that optimum PH for biogas production was PH 7,719 ml. The optimum PH for COD removal is PH 6, 72.39 %. The operation mode COD:N for biogas production and COD removal is 500:7, with the production value is 601 ml and COD removal value is 63.85 %. The research’s conclusion, the PH optimum for biogas production was PH 7, then the optimum PH for COD removal is PH 6. The optimum operation mode COD:N for biogas production and COD removal was 500:7

  13. Microbial Community Composition of Polyhydroxyalkanoate-Accumulating Organisms in Full-Scale Wastewater Treatment Plants Operated in Fully Aerobic Mode

    Science.gov (United States)

    Oshiki, Mamoru; Onuki, Motoharu; Satoh, Hiroyasu; Mino, Takashi

    2013-01-01

    The removal of biodegradable organic matter is one of the most important objectives in biological wastewater treatments. Polyhydroxyalkanoate (PHA)-accumulating organisms (PHAAOs) significantly contribute to the removal of biodegradable organic matter; however, their microbial community composition is mostly unknown. In the present study, the microbial community composition of PHAAOs was investigated at 8 full-scale wastewater treatment plants (WWTPs), operated in fully aerobic mode, by fluorescence in situ hybridization (FISH) analysis and post-FISH Nile blue A (NBA) staining techniques. Our results demonstrated that 1) PHAAOs were in the range of 11–18% in the total number of cells, and 2) the microbial community composition of PHAAOs was similar at the bacterial domain/phylum/class/order level among the 8 full-scale WWTPs, and dominant PHAAOs were members of the class Alphaproteobacteria and Betaproteobacteria. The microbial community composition of α- and β-proteobacterial PHAAOs was examined by 16S rRNA gene clone library analysis and further by applying a set of newly designed oligonucleotide probes targeting 16S rRNA gene sequences of α- or β-proteobacterial PHAAOs. The results demonstrated that the microbial community composition of PHAAOs differed in the class Alphaproteobacteria and Betaproteobacteria, which possibly resulted in a different PHA accumulation capacity among the WWTPs (8.5–38.2 mg-C g-VSS−1 h−1). The present study extended the knowledge of the microbial diversity of PHAAOs in full-scale WWTPs operated in fully aerobic mode. PMID:23257912

  14. Single Spatial-Mode Room-Temperature-Operated 3.0 to 3.4 micrometer Diode Lasers

    Science.gov (United States)

    Frez, Clifford F.; Soibel, Alexander; Belenky, Gregory; Shterengas, Leon; Kipshidze, Gela

    2010-01-01

    Compact, highly efficient, 3.0 to 3.4 m light emitters are in demand for spectroscopic analysis and identification of chemical substances (including methane and formaldehyde), infrared countermeasures technologies, and development of advanced infrared scene projectors. The need for these light emitters can be currently addressed either by bulky solid-state light emitters with limited power conversion efficiency, or cooled Interband Cascade (IC) semiconductor lasers. Researchers here have developed a breakthrough approach to fabrication of diode mid-IR lasers that have several advantages over IC lasers used for the Mars 2009 mission. This breakthrough is due to a novel design utilizing the strain-engineered quantum-well (QW) active region and quinternary barriers, and due to optimization of device material composition and growth conditions (growth temperatures and rates). However, in their present form, these GaSb-based laser diodes cannot be directly used as a part of sensor systems. The device spectrum is too broad to perform spectroscopic analysis of gas species, and operating currents and voltages are too high. In the current work, the emitters were fabricated as narrow-ridge waveguide index-guided lasers rather than broad stripe-gain guided multimode Fabry-Perot (FP) lasers as was done previously. These narrow-ridge waveguide mid-IR lasers exhibit much lower power consumptions, and can operate in a single spatial mode that is necessary for demonstration of single-mode distributed feedback (DBF) devices for spectroscopic applications. These lasers will enable a new generation of compact, tunable diode laser spectrometers with lower power consumption, reduced complexity, and significantly reduced development costs. These lasers can be used for the detection of HCN, C2H2, methane, and ethane.

  15. Integrated simulations of H-mode operation in ITER including core fuelling, divertor detachment and ELM control

    Science.gov (United States)

    Polevoi, A. R.; Loarte, A.; Dux, R.; Eich, T.; Fable, E.; Coster, D.; Maruyama, S.; Medvedev, S. Yu.; Köchl, F.; Zhogolev, V. E.

    2018-05-01

    ELM mitigation to avoid melting of the tungsten (W) divertor is one of the main factors affecting plasma fuelling and detachment control at full current for high Q operation in ITER. Here we derive the ITER operational space, where ELM mitigation to avoid melting of the W divertor monoblocks top surface is not required and appropriate control of W sources and radiation in the main plasma can be ensured through ELM control by pellet pacing. We apply the experimental scaling that relates the maximum ELM energy density deposited at the divertor with the pedestal parameters and this eliminates the uncertainty related with the ELM wetted area for energy deposition at the divertor and enables the definition of the ITER operating space through global plasma parameters. Our evaluation is thus based on this empirical scaling for ELM power loads together with the scaling for the pedestal pressure limit based on predictions from stability codes. In particular, our analysis has revealed that for the pedestal pressure predicted by the EPED1  +  SOLPS scaling, ELM mitigation to avoid melting of the W divertor monoblocks top surface may not be required for 2.65 T H-modes with normalized pedestal densities (to the Greenwald limit) larger than 0.5 to a level of current of 6.5–7.5 MA, which depends on assumptions on the divertor power flux during ELMs and between ELMs that expand the range of experimental uncertainties. The pellet and gas fuelling requirements compatible with control of plasma detachment, core plasma tungsten accumulation and H-mode operation (including post-ELM W transient radiation) have been assessed by 1.5D transport simulations for a range of assumptions regarding W re-deposition at the divertor including the most conservative assumption of zero prompt re-deposition. With such conservative assumptions, the post-ELM W transient radiation imposes a very stringent limit on ELM energy losses and the associated minimum required ELM frequency. Depending on

  16. 33 CFR 117.822 - Beaufort Channel, NC.

    Science.gov (United States)

    2010-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.822 Beaufort Channel, NC. The... bridge need not open between the hours of 6:30 a.m. to 8 a.m. and 4:30 p.m. to 6 p.m. (b) From 10 p.m. to...

  17. Opportunities and challenges for photon diagnostics at the soft X-ray FEL FLASH in simultaneous operation mode (Conference Presentation)

    Science.gov (United States)

    Kuhlmann, Marion; Treusch, Rolf; Plönjes-Palm, Elke; Faatz, Bart; Tiedtke, Kai; Braune, Markus; Keitel, Barbara

    2017-06-01

    FLASH operates two distinguished undulator sections driven by one linear accelerator. In the 11th year of user operation the grown demands for detailed photon beam performances are doubled approached. The more complex machine settings and setup times require a more and more efficient determination of its characteristics concerning electron- and photon-beams. The photon diagnostics systems, e.g. gas monitor detection, photon-ion spectroscopy, or diffractive tools, not only have to deal on a regular basis with fundamental wavelengths between 4nm and 90nm, also they have to be reliable from 1µJ up to 1mJ of average single pulse energy. For the success of the experiments the error bars of many diagnostics measurements need to be pushed into their current limits and developments to go further are always issued. Especial, the pulse duration in conjunction with the spectral width has been accessed in the last year. Direct approaches of fundamental wavelengths below the Nitrogene K-edge and higher harmonics in and below the water window were achieved. While in principal distinguished to each other, the photon diagnostics tools of FLASH1 and FLASH2 add-up to a more complete understanding of the other. Together they allow for a better perspective towards further developments and a more suitable use of beam times. The intermingled knowledge of electron- and photon-beams is essential for an FEL particular in simultaneous operation mode. Examples out of regular user operation and distinguished FEL-studies are given to illustrate the current state of the photon diagnostics at FLASH.

  18. Bioremediation of anthracene contaminated soil in bio-slurry phase reactor operated in periodic discontinuous batch mode

    International Nuclear Information System (INIS)

    Prasanna, D.; Venkata Mohan, S.; Purushotham Reddy, B.; Sarma, P.N.

    2008-01-01

    Bioremediation of soil-bound anthracene was studied in a series of bio-slurry phase reactors operated in periodic discontinuous/sequencing batch mode under anoxic-aerobic-anoxic microenvironment using native soil microflora. Five reactors were operated for a total cycle period of 144 h (6 days) at soil loading rate of 16.66 kg soil/m 3 /day at 30 ± 2 o C temperature. The performance of the bioreactors was studied at various substrate loading rates (volumetric substrate loading rate (SLR), 0.1, 0.2 and 0.3 g anthracene/kg soil/day) with and without bioaugmentation (domestic sewage inoculum; 2 x 10 6 CFU/g of soil). Control reactor (without microflora) showed negligible degradation of anthracene due to the absence of biological activity. The performance of the bio-slurry system with respect to anthracene degradation was found to depend on both substrate loading rate and bioaugmentation. Application of bioaugmentation showed positive influence on the rate of degradation of anthracene. Anthracene degradation data was analysed using different kinetic models to understand the mechanism of bioremediation process in the bio-slurry phase system. Variation in pH/oxidation-reduction potential (ORP), soil microflora and oxygen consumption rate correlated well with the substrate degradation pattern observed during soil slurry phase anthracene degradation

  19. Extended dynamic mode decomposition with dictionary learning: A data-driven adaptive spectral decomposition of the Koopman operator.

    Science.gov (United States)

    Li, Qianxiao; Dietrich, Felix; Bollt, Erik M; Kevrekidis, Ioannis G

    2017-10-01

    Numerical approximation methods for the Koopman operator have advanced considerably in the last few years. In particular, data-driven approaches such as dynamic mode decomposition (DMD) 51 and its generalization, the extended-DMD (EDMD), are becoming increasingly popular in practical applications. The EDMD improves upon the classical DMD by the inclusion of a flexible choice of dictionary of observables which spans a finite dimensional subspace on which the Koopman operator can be approximated. This enhances the accuracy of the solution reconstruction and broadens the applicability of the Koopman formalism. Although the convergence of the EDMD has been established, applying the method in practice requires a careful choice of the observables to improve convergence with just a finite number of terms. This is especially difficult for high dimensional and highly nonlinear systems. In this paper, we employ ideas from machine learning to improve upon the EDMD method. We develop an iterative approximation algorithm which couples the EDMD with a trainable dictionary represented by an artificial neural network. Using the Duffing oscillator and the Kuramoto Sivashinsky partical differential equation as examples, we show that our algorithm can effectively and efficiently adapt the trainable dictionary to the problem at hand to achieve good reconstruction accuracy without the need to choose a fixed dictionary a priori. Furthermore, to obtain a given accuracy, we require fewer dictionary terms than EDMD with fixed dictionaries. This alleviates an important shortcoming of the EDMD algorithm and enhances the applicability of the Koopman framework to practical problems.

  20. Control of spool position of on/off solenoid operated hydraulic valve by sliding-mode controller

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hak; Hong, Hyun Wook; Park, Myeong Kwan [Pusan National University, Busan (Korea, Republic of); Yun, Young Won [KHPS, Busan (Korea, Republic of)

    2015-11-15

    The use of on/off solenoid operated hydraulic valves instead of proportional valves has been attracting the interest of many researchers and engineers. However, there exist difficulties in controlling the on/off valve because of highly nonlinear characteristics including hysteresis and saturation. This paper considers the application of on/off solenoid operated hydraulic valves to control position of a hydraulic cylinder with the aim of evaluating, feasibility and practicability of their implementation and understanding the potential benefits when they are used in existing hydraulic systems. Assuming that only the current is measured, a sliding mode observer is designed to estimate the spool position and velocity. To alleviate the aforementioned difficulties in controlling the spool position, a nonlinear observer-based controller of an on/off solenoid valve is designed, taking into account the estimated values, based on a nonlinear model including hysteresis and saturation. The control objective is to track a desired spool trajectory. Simulation and experimental results illustrate the efficiency of the designed controller. The proposed controller is validated again in a single-rod hydraulic actuator. Experimental results show that the fluid flow through the valve orifice by controlling the spool position was successfully controlled.

  1. p-Nitrophenol removal by combination of powdered activated carbon adsorption and ultrafiltration - comparison of different operational modes.

    Science.gov (United States)

    Ivancev-Tumbas, Ivana; Hobby, Ralph; Küchle, Benjamin; Panglisch, Stefan; Gimbel, Rolf

    2008-09-01

    Ultrafiltration is classified as a low-pressure membrane technology which effectively removes particulate matter and microorganisms and to a certain extent dissolved organic matter (15-25%) and colour. The technology has been optimized and is becoming competitive compared to conventional processes for larger scale plant capacities. In combination with activated carbon it is an effective barrier regarding the removal of synthetic organic chemicals. Growing interest in ultrafiltration raises the question of better usage of the adsorption capacity of powdered activated carbon (PAC) used in combination with this low-pressure membrane technique. This paper presents a pilot plant study of different PAC dosing procedures within a combined hybrid membrane IN/OUT process for removal of p-nitrophenol (PNP) from water (c(0)=1mg/L) under real case conditions (e.g. usage of the same module for the whole duration of the experiment, backwashing with permeate water, no separate saturation of the membrane with substance without presence of carbon). p-Nitrophenol was chosen as an appropriate test substance to assess the efficiency of different operation modes. Dead-end and cross-flow filtration were compared with respect to different PAC dosing procedures: continuous dosing into a continuously stirred tank reactor (CSTR) in front of the module and direct dosing into the pipe in front of the module (continuous, single-pulse and multi-pulse dosing). There was no advantage in cross-flow mode over dead-end referring to PNP concentration in the permeate. Relating to the carbon dosing procedure, the best results were obtained for continuous PAC addition. The option of dosing directly into the pipe has the advantage of no additional tank being necessary. In the case of single-pulse dosing, the formation of a carbon layer on the membrane surface was assumed and an LDF model applied for a simplified estimation of the "breakthrough behaviour" in the thus formed "PAC filter layer".

  2. Mode-locking operation of a flash-lamp-pumped Nd:YAG laser at 1.064 μm with Zakharov-Manakov solitons

    International Nuclear Information System (INIS)

    Andreana, M; Tonello, A; Couderc, V; Baronio, F; Conforti, M; De Angelis, C

    2011-01-01

    We report experimental results on the mode-locked operation of a flash-lamp-pumped Nd:YAG laser at 1.064 μm. The KTP crystal, which induces passive mode-locking, exploits the existence and properties of spatial Zakharov-Manakov soliton dynamics. A train of pulses with duration close to 100 ps, repetition rate of 136 MHz and modulation depth almost 100% has been produced. The mode-locked pulses are modulated with a longer 180 ns pulse envelope with repetition rate of 10 Hz

  3. Comparison of emissions from on-road sources using a mobile laboratory under various driving and operational sampling modes

    Directory of Open Access Journals (Sweden)

    M. Zavala

    2009-01-01

    Full Text Available Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program (BORAQIP for the Mexicali-Imperial Valley in 2005. We analyze the variability of measured emission ratios for emitted NOx, CO, specific VOCs, NH3, and some primary fine particle components and properties by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NOx mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were

  4. Comparative economic efficiency, operating costs and fuel consumption rates of freight transport modes between the largest industrial cities and seaports in South Africa

    Directory of Open Access Journals (Sweden)

    W J (Wessel Pienaar

    2013-09-01

    Full Text Available The paper deals with aspects of efficiency within the five modes of freight transport, with special reference to the operating cost and fuel consumption rates between South Africa’s largest industrial cities and seaports. In particular, the paper deals with (a the opportunities that exist for the achievement of efficiency in freight transport; (b the subgroups of economies that can enhance efficiency attainment in the freight transport industry; (c prevailing cost structures, operating cost and fuel consumption rates within the five modes of freight transport; and (d the salient economic features of the freight transport market. The research approach and methodology combine (a a literature survey; (b empiric research, (c an analysis of the cost structures of freight transport operators from different modes of transport; and (d interviews conducted with specialists in the freight transport industry.

  5. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode and/or with gas amplification

    CERN Document Server

    Charpak, Georges; Breuil, P; Peskov, Vladimir

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and cetera. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification. . To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of 1. The second type alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10E4). A detailed comparison between these two detectors is given as well as comparison with the commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible ap...

  6. Physics of increased edge electron temperature and density turbulence during ELM-free QH-mode operation on DIII-D

    Science.gov (United States)

    Sung, C.; Rhodes, T. L.; Staebler, G. M.; Yan, Z.; McKee, G. R.; Smith, S. P.; Osborne, T. H.; Peebles, W. A.

    2018-05-01

    For the first time, we report increased edge electron temperature and density turbulence levels ( T˜ e and n˜ e) in Edge Localized Mode free Quiescent H-mode (ELM-free QH-mode) plasmas as compared to the ELMing time period. ELMs can severely damage plasma facing components in fusion plasma devices due to their large transient energy transport, making ELM-free operation a highly sought after goal. The QH-mode is a candidate for this goal as it is ELM-free for times limited only by hardware constraints. It is found that the driving gradients decrease during the QH-mode compared to the ELMing phase, however, a significant decrease in the ExB shearing rate is also observed that taken together is consistent with the increased turbulence. These results are significant as the prediction and control of ELM-free H-mode regimes are crucial for the operation of future fusion devices such as ITER. The changes in the linear growth rates calculated by CGYRO [Candy et al., J. Comput. Phys. 324, 73 (2016)] and the measured ExB shearing rate between ELMing and QH-mode phases are qualitatively consistent with these turbulence changes. Comparison with ELMing and 3D fields ELM suppressed H-mode finds a similar increase in T˜ e and n˜ e, however, with distinctly different origins, the increased driving gradients rather than the changes in the ExB shearing rate in 3D fields ELM suppressed the H-mode. However, linear gyrokinetic calculation results are generally consistent with the increased turbulence in both ELM-controlled discharges.

  7. Current sheet characteristics of a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode

    Science.gov (United States)

    Liu, Shuai; Huang, Yizhi; Guo, Haishan; Lin, Tianyu; Huang, Dong; Yang, Lanjun

    2018-05-01

    The axial characteristics of a current sheet in a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode are reported. The accelerator is powered by a fourteen stage pulse forming network. The capacitor and inductor in each stage are 1.5 μF and 300 nH, respectively, and yield a damped oscillation square wave of current with a pulse width of 20.6 μs. Magnetic probes and photodiodes are placed at various axial positions to measure the behavior of the current sheet. Both magnetic probe and photodiode signals reveal a secondary breakdown when the current reverses the direction. An increase in the discharge current amplitude and a decrease in pressure lead to a decrease in the current shedding factor. The current sheet velocity and thickness are nearly constant during the run-down phase under the first half-period of the current. The current sheet thicknesses are typically in the range of 25 mm to 40 mm. The current sheet velocities are in the range of 10 km/s to 45 km/s when the discharge current is between 10 kA and 55 kA and the gas prefill pressure is between 30 Pa and 800 Pa. The experimental velocities are about 75% to 90% of the theoretical velocities calculated with the current shedding factor. One reason for this could be that the idealized snowplow analysis model ignores the surface drag force.

  8. Generation of Q-Switched Mode-Locked Erbium-Doped Fiber Laser Operating in Dark Regime

    International Nuclear Information System (INIS)

    Tiu, Zian Cheak; Zarei, Arman; Ahmad, Harith; Harun, Sulaiman Wadi

    2016-01-01

    We demonstrate a stable Q-switched mode-locked erbium-doped fiber laser (EDFL) operating in dark regime based on the nonlinear polarization rotation technique. The EDFL produces a pulse train where the Q-switching envelope is formed by multiple dark pulses. The repetition rate of the Q-switched envelope can be increased from 0.96 kHz to 3.26 kHz, whereas the pulse width reduces from 211 μs to 86 μs. The highest pulse of 479 nJ is obtained at the pump power of 55 mW. It is also observed that the dark pulses inside the Q-switching envelope consist of two parts: square and trailing dark pulses. The shortest pulse width of the dark square pulse is obtained at 40.5 μs when the pump power is fixed at 145 mW. The repetition rate of trailing dark pulses can be increased from 27.62 kHz to 50 kHz as the pump power increases from 55 mW to 145 mW. (paper)

  9. Short primary linear drive designed for synchronous and induction operation mode with on-board energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes Neto, Tobias Rafael

    2012-06-28

    guide way (induction rail or stationary magnets), and the energy and information should be transmitted contactless to the active vehicle. Regarding the features of the material handling application, the short or long primary topology can be used. Short primary linear drives on passive track are advantageous in material handling applications, where high precision, moderate dynamic, very long track and closed paths are required. Nevertheless, depending on the requirements of the section, the costs can be reduced considerably by using a simple induction rail at the long transporting sections, instead of permanent magnets on the track. Therefore, in this thesis a combined operation of permanent magnet linear synchronous motor (PMLSM) and linear induction motor (LIM) is applied to operate the short primary as vehicle, avoiding adjustment or releasing of the material during the drive cycle. In summary, the passive track will consist of two section types: a high thrust force section (processing station) with PMLSM and a low thrust force section with LIM (transporting section). To the author's knowledge, using two operation modes (PMLSM / LIM) in the same drive is a new approach. A theoretical and experimental study was conducted to assess the feasibility of employing the short primary linear motor for a flexible manufacturing system, in which a contactless energy transmission provides the basic power and an ultracapacitor (UC) storage system provides the peak power. The system uses a bidirectional DC-DC converter between the ultracapacitor bank and the DC-link, to make sure that the ultracapacitor can store the braking energy and supply the peak power demanded by the active vehicle. A control strategy has been developed for controlling the ultracapacitor to deliver the peak of power, to charge, to protect against overvoltage and to recover the energy generated when the vehicle is braking. A control strategy for the transition between the two operation modes (PMLSM / LIM

  10. Production of structured lipids by acidolysis of an EPA-enriched fish oil and caprylic acid in a packed bed reactor: analysis of three different operation modes.

    Science.gov (United States)

    González Moreno, P A; Robles Medina, A; Camacho Rubio, F; Camacho Páez, B; Molina Grima, E

    2004-01-01

    Structured triacylglycerols (ST) enriched in eicosapentaenoic acid (EPA) in position 2 of the triacylglycerol (TAG) backbone were synthesized by acidolysis of a commercially available EPA-rich oil (EPAX4510, 40% EPA) and caprylic acid (CA), catalyzed by the 1,3-specific immobilized lipase Lipozyme IM. The reaction was carried out in a packed bed reactor (PBR) operating in two ways: (1) by recirculating the reaction mixture from the exit of the bed to the substrate reservoir (discontinuous mode) and (2) in continuous mode, directing the product mixture leaving the PBR to a product reservoir. By operating in these two ways and using a simple kinetic model, representative values for the apparent kinetic constants (kX) for each fatty acid (native, Li or odd, M) were obtained. The kinetic model assumes that the rate of incorporation of a fatty acid into TAG per amount of enzyme, rX (mole/(h g lipase)) is proportional to the extent of the deviation from the equilibrium for each fatty acid (i.e., the difference of concentration between the fatty acid in the triacylglycerol and the concentration of the same fatty acid in the triacylglycerol once the equilibrium of the acidolysis reaction is reached). The model allows comparing the two operating modes through the processing intensity, defined as mLt/(V[TG]0) and mL/(q[TG]0), for the discontinuous and continuous operation modes, respectively. In discontinuous mode, ST with 59.5% CA and 9.6% EPA were obtained. In contrast, a ST with 51% CA and 19.6% EPA were obtained when using the continuous operation mode. To enhance the CA incorporation when operating in continuous mode, a two-step acidolysis reaction was performed (third operation mode). This continuous two-step process yields a ST with a 64% CA and a 15% EPA. Finally, after purifying the above ST in a preparative silica gel column, impregnated with boric acid, a ST with 66.9% CA and 19.6% EPA was obtained. The analysis by reverse phase and Ag+ liquid chromatography of

  11. The Choice of Entry Mode for Successful Business in an Emerging Market : Norwegian Business Operations in Indonesia

    OpenAIRE

    Ødegård, Sunniva Hellandsvik

    2016-01-01

    Master thesis Business Administration - University of Agder 2016 The main topic for this master thesis is the choice of entry mode for successful business in emerging markets, with a focus on Norwegian companies in the Indonesian market. The problem statement of the thesis is as follows: What are the main factors affecting the choice of entry mode for Norwegian companies in the Indonesian market? Several studies on the choice of entry modes have previously been conducted. Howev...

  12. Potential profiles in the central core of the cathode in the star mode operation in an inertial-electrostatic fusion neutron source

    International Nuclear Information System (INIS)

    Yoshikawa, K.; Masuda, K.; Toku, H.

    2003-01-01

    After the successful measurements of the localized electric fields in the center-spot mode operation with relatively large space-charge effects by the laser-induced fluorescence (LIF) method, measurements of potential profiles in the star mode operation with small space-charge effects on helium gas are made in the central cathode core region of an Inertial-Electrostatic Confinement Fusion (IECF) neutron source, which is most suitable to neutron calibration in the fusion devices. Since the high-voltage is required to the star mode operation on deuterium gas, it is predicted to bring about very small beam space charge-related potential. To increase accuracy, we adopted n=4 (2 1 S to 4 1 D:HeI) transition, instead of previous n=3, which is most sensitive to the local electric fields in the Stark transition, and verified using the well-known U-shaped hollow cathode potential. The localized electric fields thus measured by LIF method using n=4 transition show negligible electric fields in the star mode compared with the center-spot mode. (author)

  13. Terahertz-bandwidth coherence measurements of a quantum dash laser in passive and active mode-locking operation.

    Science.gov (United States)

    Martin, Eamonn; Watts, Regan; Bramerie, Laurent; Shen, Alexandre; Gariah, Harry; Blache, Fabrice; Lelarge, Francois; Barry, Liam

    2012-12-01

    This research carries out coherence measurements of a 42.7 GHz quantum dash (QDash) semiconductor laser when passively, electrically, and optically mode-locked. Coherence of the spectral lines from the mode-locked laser is determined by examining the radio frequency beat-tone linewidth as the mode spacing is increased up to 1.1 THz. Electric-field measurements of the QDash laser are also presented, from which a comparison between experimental results and accepted theory for coherence in passively mode-locked lasers has been performed.

  14. “Synthesis-on” and “synthesis-off” modes of carbon arc operation during synthesis of carbon nanotubes

    International Nuclear Information System (INIS)

    Yatom, Shurik; Selinsky, Rachel S.

    2017-01-01

    Arc discharge synthesis of single-walled carbon nanotubes (SWCNTs) remains largely uncontrollable, due to incomplete understanding of the synthetic process itself. Here, we show that synthesis of SWCNTs by a carbon arc may not constitute a single continuous process, but may instead consist of two distinct modes. One of these, a “synthesis-on” mode, produces the majority of the nanomaterials. During the synthesis-on mode, proportionally more carbon nanotubes are collected than in another mode, a “synthesis-off” mode. Both synthesis-on and synthesis-off modes for a typical arc configuration, employing a hollow anode filled with a mixture of powdered metal catalyst and graphite, were characterized by using in situ electrical, imaging, and spectroscopic diagnostics, along with ex situ imaging and spectroscopy. The synthesis-on mode duration is rare compared to the total arc run-time, helping to explain the poor selectivity found in the final collected products, a known inadequacy of arc synthesis. Finally, the rarity of the synthesis on mode occurence may be due to the synthesis off mode being more favorable energetically.

  15. Performance of a GM tube based environmental dose rate monitor operating in the Time-To-Count mode

    Energy Technology Data Exchange (ETDEWEB)

    Zickefoose, J.; Kulkarni, T.; Martinson, T.; Phillips, K.; Voelker, M. [Canberra Industries Inc. (United States)

    2015-07-01

    The events at the Fukushima Daiichi power plant in the aftermath of a natural disaster underline the importance of a large array of networked environmental monitors to cover areas around nuclear power plants. These monitors should meet a few basic criteria: have a uniform response over a wide range of gamma energies, have a uniform response over a wide range of incident angles, and have a large dynamic range. Many of these criteria are met if the probe is qualified to the international standard IEC 60532 (Radiation protection instrumentation - Installed dose rate meters, warning assemblies and monitors - X and gamma radiation of energy between 50 keV and 7 MeV), which specifically deals with energy response, angle of incidence, dynamic range, response time, and a number of environmental characteristics. EcoGamma is a dual GM tube environmental gamma radiation monitor designed specifically to meet the requirements of IEC 60532 and operate in the most extreme conditions. EcoGamma utilizes two energy compensated GM tubes operating with a Time-To-Count (TTC) collection algorithm. The TTC algorithm extends the lifetime and range of a GM tube significantly and allows the dual GM tube probe to achieve linearity over approximately 10 decades of gamma dose rate (from the Sv/hr range to 100 Sv/hr). In the TTC mode of operation, the GM tube is not maintained in a biased condition continuously. This is different from a traditional counting system where the GM tube is held at a constant bias continuously and the total number of strikes that the tube registers are counted. The traditional approach allows for good sensitivity, but does not lend itself to a long lifetime of the tube and is susceptible to linearity issues at high count rates. TTC on the other hand only biases the tube for short periods of time and in effect measures the time between events, which is statistically representative of the total strike rate. Since the tube is not continually biased, the life of the tube

  16. Performance of a GM tube based environmental dose rate monitor operating in the Time-To-Count mode

    International Nuclear Information System (INIS)

    Zickefoose, J.; Kulkarni, T.; Martinson, T.; Phillips, K.; Voelker, M.

    2015-01-01

    The events at the Fukushima Daiichi power plant in the aftermath of a natural disaster underline the importance of a large array of networked environmental monitors to cover areas around nuclear power plants. These monitors should meet a few basic criteria: have a uniform response over a wide range of gamma energies, have a uniform response over a wide range of incident angles, and have a large dynamic range. Many of these criteria are met if the probe is qualified to the international standard IEC 60532 (Radiation protection instrumentation - Installed dose rate meters, warning assemblies and monitors - X and gamma radiation of energy between 50 keV and 7 MeV), which specifically deals with energy response, angle of incidence, dynamic range, response time, and a number of environmental characteristics. EcoGamma is a dual GM tube environmental gamma radiation monitor designed specifically to meet the requirements of IEC 60532 and operate in the most extreme conditions. EcoGamma utilizes two energy compensated GM tubes operating with a Time-To-Count (TTC) collection algorithm. The TTC algorithm extends the lifetime and range of a GM tube significantly and allows the dual GM tube probe to achieve linearity over approximately 10 decades of gamma dose rate (from the Sv/hr range to 100 Sv/hr). In the TTC mode of operation, the GM tube is not maintained in a biased condition continuously. This is different from a traditional counting system where the GM tube is held at a constant bias continuously and the total number of strikes that the tube registers are counted. The traditional approach allows for good sensitivity, but does not lend itself to a long lifetime of the tube and is susceptible to linearity issues at high count rates. TTC on the other hand only biases the tube for short periods of time and in effect measures the time between events, which is statistically representative of the total strike rate. Since the tube is not continually biased, the life of the tube

  17. A comparison of co-current and counter-current modes of operation for a novel hydrogen-permselective membrane dual-type FTS reactor in GTL technology

    Energy Technology Data Exchange (ETDEWEB)

    Rahimpour, M.R.; Forghani, A.A.; Mostafazadeh, A. Khosravanipour; Shariati, A. [Chemical Engineering Department, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz 71345 (Iran)

    2010-01-15

    In this work, a comparison of co-current and counter-current modes of operation for a novel hydrogen-permselective membrane reactor for Fischer-Tropsch Synthesis (FTS) has been carried out. In both modes of operations, a system with two-catalyst bed instead of one single catalyst bed is developed for FTS reactions. In the first catalytic reactor, the synthesis gas is partly converted to products in a conventional water-cooled fixed-bed reactor, while in the second reactor which is a membrane fixed-bed reactor, the FTS reactions are completed and heat of reaction is used to preheat the feed synthesis gas to the first reactor. In the co-current mode, feed gas is entered into the tubes of the second reactor in the same direction with the reacting gas stream in shell side while in the counter-current mode the gas streams are in the opposite direction. Simulation results for both co-current and counter-current modes have been compared in terms of temperature, gasoline and CO{sub 2} yields, H{sub 2} and CO conversion, selectivity of components as well as permeation rate of hydrogen through the membrane. The results showed that the reactor in the co-current configuration operates with lower conversion and lower permeation rate of hydrogen, but it has more favorable profile of temperature. The counter-current mode of operation decreases undesired products such as CO{sub 2} and CH{sub 4} and also produces more gasoline. (author)

  18. Generalized coupling resonance modeling, analysis, and active damping of multi-parallel inverters in microgrid operating in grid-connected mode

    DEFF Research Database (Denmark)

    Chen, Zhiyong; Chen, Yandong; Guerrero, Josep M.

    2016-01-01

    This paper firstly presents an equivalent coupling circuit modeling of multi-parallel inverters in microgrid operating in grid-connected mode. By using the model, the coupling resonance phenomena are explicitly investigated through the mathematical approach, and the intrinsic and extrinsic...

  19. Predictive digital peak current mode controller for DC-DC converters capable of operating over the full 0-100% duty cycle range

    DEFF Research Database (Denmark)

    Andersen, Karsten Holm; Nymand, Morten

    2017-01-01

    ) and discontinuous conduction mode (DCM) and supports high switching frequencies even with low cost A/D converters. The proposed controller is implemented in a Field Programmable Gate Array (FPGA) to control a 450 W buck converter and the experimental results verify the controller's capability to operate in the full...

  20. Experimental investigation of the sloshing motion of the water free surface in the draft tube of a Francis turbine operating in synchronous condenser mode

    Science.gov (United States)

    Vagnoni, Elena; Favrel, Arthur; Andolfatto, Loïc; Avellan, François

    2018-06-01

    Hydropower units may be required to operate in condenser mode to supply reactive power. In this operating mode, the water level in the turbine or pump-turbine is decreased below the runner by closing the guide vanes and injecting pressurized air. While operating in condenser mode the machine experiences power losses due to several air-water interaction phenomena which cause air losses. One of such phenomena is the sloshing motion of the water free surface below the runner in the draft tube cone of a Francis turbine. The objective of the present work is to experimentally investigate the sloshing motion of the water free surface in the draft tube cone of a reduced scale physical model of a Francis turbine operating in condenser mode. Images acquisition and simultaneous pressure fluctuation measurements are performed and an image processing method is developed to investigate amplitude and frequency of the sloshing motion of the free surface. It is found that this motion is excited at the natural frequency of the water volume and corresponds to the azimuthal wavenumber m = 1 of a rotating gravity wave. The amplitude of the motion is perturbed by wave breaking and it decreases by increasing the densimetric Froude number. The sloshing frequency slightly increases with respect to the natural frequency of the water volume by increasing the densimetric Froude number. Moreover, it results that this resonant phenomenon is not related to the torque perturbation.

  1. Observation of dynamic interactions between fundamental and second-harmonic modes in a high-power sub-terahertz gyrotron operating in regimes of soft and hard self-excitation.

    Science.gov (United States)

    Saito, Teruo; Tatematsu, Yoshinori; Yamaguchi, Yuusuke; Ikeuchi, Shinji; Ogasawara, Shinya; Yamada, Naoki; Ikeda, Ryosuke; Ogawa, Isamu; Idehara, Toshitaka

    2012-10-12

    Dynamic mode interaction between fundamental and second-harmonic modes has been observed in high-power sub-terahertz gyrotrons [T. Notake et al., Phys. Rev. Lett. 103, 225002 (2009); T. Saito et al. Phys. Plasmas 19, 063106 (2012)]. Interaction takes place between a parasitic fundamental or first-harmonic (FH) mode and an operating second-harmonic (SH) mode, as well as among SH modes. In particular, nonlinear excitation of the parasitic FH mode in the hard self-excitation regime with assistance of a SH mode in the soft self-excitation regime was clearly observed. Moreover, both cases of stable two-mode oscillation and oscillation of the FH mode only were observed. These observations and theoretical analyses of the dynamic behavior of the mode interaction verify the nonlinear hard self-excitation of the FH mode.

  2. Relationship between composition of mixture charged and that in circulation in an auto refrigerant cascade and a J-T refrigerator operating in liquid refrigerant supply mode

    Science.gov (United States)

    Sreenivas, Bura; Nayak, H. Gurudath; Venkatarathnam, G.

    2017-01-01

    The composition of the refrigerant mixture in circulation during steady state operation of J-T and allied refrigerators is not the same as that charged due to liquid hold up in the heat exchangers and phase separators, as well as the differential solubility of different refrigerant components in the compressor lubricating oil. The performance of refrigerators/liquefiers operating on mixed refrigerant cycles is dependent on the mixture composition. It is therefore important to charge the right mixture that results in an optimum composition in circulation during steady state operation. The relationship between the charged and circulating composition has been experimentally studied in a J-T refrigerator operating in the liquid refrigerant supply (LRS) mode and an auto refrigerant cascade refrigerator (with a phase separator) operating in the gas refrigerant supply (GRS) mode. The results of the study are presented in this work. The results show that the method presented earlier for J-T refrigerators operating in GRS mode is also applicable in the case of refrigerators studied in this work.

  3. Viability of fuel switching of a gas-fired power plant operating in chemical looping combustion mode

    International Nuclear Information System (INIS)

    Basavaraja, R.J.; Jayanti, S.

    2015-01-01

    CLC (chemical looping combustion) promises to be a more efficient way of CO 2 capture than conventional oxy-fuel combustion or post-combustion absorption. While much work has been done on CLC in the past two decades, the issue of multi-fuel compatibility has not been addressed sufficiently, especially with regard to plant layout and reactor design. In the present work, it is shown that this is non-trivial in the case of a CLC-based power plant. The underlying factors have been examined in depth and design criteria for fuel compatibility have been formulated. Based on these, a layout has been developed for a power plant which can run with either natural gas or syngas without requiring equipment changes either on the steam side or on the furnace side. The layout accounts for the higher CO 2 compression costs associated with the use of syngas in place of natural gas. The ideal thermodynamic cycle efficiency, after accounting for the energy penalty of CO 2 compression, is 43.11% and 41.08%, when a supercritical steam cycle is used with natural gas and syngas, respectively. It is shown that fuel switching can be enabled by incorporating the compatibility conditions at the design stage itself. - Highlights: • Concept of fuel sensitivity of plant layout with carbon capture and sequestration. • Power plant layout for natural gas and syngas as fuels. • Criteria for compatibility of air and fuel reactors for dual fuel mode operation. • Layout of a plant for carbon-neutral or carbon negative power generation

  4. 33 CFR 80.525 - Cape Lookout, NC to Cape Fear, NC.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cape Lookout, NC to Cape Fear, NC... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Fifth District § 80.525 Cape Lookout, NC to Cape Fear... southeast side of the Inlet. (g) Except as provided elsewhere in this section from Cape Lookout to Cape Fear...

  5. An analysis of the binding of repressor protein ModE to modABCD (molybdate transport) operator/promoter DNA of Escherichia coli.

    Science.gov (United States)

    Grunden, A M; Self, W T; Villain, M; Blalock, J E; Shanmugam, K T

    1999-08-20

    Expression of the modABCD operon in Escherichia coli, which codes for a molybdate-specific transporter, is repressed by ModE in vivo in a molybdate-dependent fashion. In vitro DNase I-footprinting experiments identified three distinct regions of protection by ModE-molybdate on the modA operator/promoter DNA, GTTATATT (-15 to -8; region 1), GCCTACAT (-4 to +4; region 2), and GTTACAT (+8 to +14; region 3). Within the three regions of the protected DNA, a pentamer sequence, TAYAT (Y = C or T), can be identified. DNA-electrophoretic mobility experiments showed that the protected regions 1 and 2 are essential for binding of ModE-molybdate to DNA, whereas the protected region 3 increases the affinity of the DNA to the repressor. The stoichiometry of this interaction was found to be two ModE-molybdate per modA operator DNA. ModE-molybdate at 5 nM completely protected the modABCD operator/promoter DNA from DNase I-catalyzed hydrolysis, whereas ModE alone failed to protect the DNA even at 100 nM. The apparent K(d) for the interaction between the modA operator DNA and ModE-molybdate was 0.3 nM, and the K(d) increased to 8 nM in the absence of molybdate. Among the various oxyanions tested, only tungstate replaced molybdate in the repression of modA by ModE, but the affinity of ModE-tungstate for modABCD operator DNA was 6 times lower than with ModE-molybdate. A mutant ModE(T125I) protein, which repressed modA-lac even in the absence of molybdate, protected the same region of modA operator DNA in the absence of molybdate. The apparent K(d) for the interaction between modA operator DNA and ModE(T125I) was 3 nM in the presence of molybdate and 4 nM without molybdate. The binding of molybdate to ModE resulted in a decrease in fluorescence emission, indicating a conformational change of the protein upon molybdate binding. The fluorescence emission spectra of mutant ModE proteins, ModE(T125I) and ModE(Q216*), were unaffected by molybdate. The molybdate-independent mutant ModE

  6. An evaluation of effects of large-scale introduction of renewable power on capacities and operation modes of power generation systems in Japan

    International Nuclear Information System (INIS)

    Yamamoto, Hiromi; Yabe, Kuniaki; Bando, Shigeru; Nagai, Yu

    2014-01-01

    This study aims to establish a methodology to adequately evaluate an optimal power generation mix in Japan taking into account load frequency control (LFC) capacity and operation modes of power plants in case of a large-scale introduction of photovoltaic and wind power. For this purpose, the authors gave such an improvement to the MM-OPG model, a power generation mix optimization model, which it can deal with different operation modes of pumped hydro power in addition to those of thermal power sources. Using the model, the authors calculated the optimal power generation mix and its corresponding operation modes of Japan's power systems in 2030 with additional insights to 2020, and obtained the following results. (1) Introduction of photovoltaic and wind can be substituted for a limited capacity of conventional power sources. The introduction of 150 GW that consists of 108GW of photovoltaic and 42GW of wind in 2030 can replace no greater than 0.5 GW of conventional power sources. (2) The introduction of the renewables will affect the operation patterns of thermal and pumped hydro power generation. The capacity factor of variable speed pumped hydro will be much greater than that of fixed speed pumped hydro since the former can supply LFC at pump modes as well as generation modes. The capacity factor of LNG combined cycle plants decreases from 43% to 29% in the case with the introduction of 150GW of renewables in 2030. On the same assumption, the average cost of power generation excluding the renewables increases by up to 0.55 JPY/kWh in 2030. (author)

  7. Emissions from large-scale medium-speed diesel engines: 2. Influence of fuel type and operating mode

    International Nuclear Information System (INIS)

    Sarvi, Arto; Zevenhoven, Ron; Fogelholm, Carl-Johan

    2008-01-01

    This paper addresses gaseous emissions smoke (soot) and particulate matter in large-scale diesel engine exhaust. The test engine was a large-scale turbocharged, after-cooled mean speed (∝ 500 rpm) direct-injection diesel engine and the power per cylinder was about 1 MW. Emission measurements were carried out on burning heavy fuel (HFO) and light fuel (LFO) oils. The test modes for the investigation were a propulsion mode (marine application) and a generator mode (power plant application). Gaseous emissions were measured according to the IMO technical code, smoke (soot) emissions were determined optically and particulate matter (PM) was measured by gravimetric impactor designed for five size fractions. In comparison the emissions from HFO and LFO utilisations indicate slightly higher NO and CO emissions for HFO, while LFO gives clearly higher emissions of hydrocarbons (HC). Emissions of soot and CO appeared to correlate very well, being very high for both fuels throughout the propulsion mode and low load, otherwise being similar for both modes. PM emissions are more than three times higher with HFO than with LFO and appear to decrease with the load except for HFO during the generator mode where an increase of PM emissions with the load is seen. Some data on sampled particles is given. (author)

  8. High-resolution empirical geomagnetic field model TS07D: Investigating run-on-request and forecasting modes of operation

    Science.gov (United States)

    Stephens, G. K.; Sitnov, M. I.; Ukhorskiy, A. Y.; Vandegriff, J. D.; Tsyganenko, N. A.

    2010-12-01

    The dramatic increase of the geomagnetic field data volume available due to many recent missions, including GOES, Polar, Geotail, Cluster, and THEMIS, required at some point the appropriate qualitative transition in the empirical modeling tools. Classical empirical models, such as T96 and T02, used few custom-tailored modules to represent major magnetospheric current systems and simple data binning or loading-unloading inputs for their fitting with data and the subsequent applications. They have been replaced by more systematic expansions of the equatorial and field-aligned current contributions as well as by the advanced data-mining algorithms searching for events with the global activity parameters, such as the Sym-H index, similar to those at the time of interest, as is done in the model TS07D (Tsyganenko and Sitnov, 2007; Sitnov et al., 2008). The necessity to mine and fit data dynamically, with the individual subset of the database being used to reproduce the geomagnetic field pattern at every new moment in time, requires the corresponding transition in the use of the new empirical geomagnetic field models. It becomes more similar to runs-on-request offered by the Community Coordinated Modeling Center for many first principles MHD and kinetic codes. To provide this mode of operation for the TS07D model a new web-based modeling tool has been created and tested at the JHU/APL (http://geomag_field.jhuapl.edu/model/), and we discuss the first results of its performance testing and validation, including in-sample and out-of-sample modeling of a number of CME- and CIR-driven magnetic storms. We also report on the first tests of the forecasting version of the TS07D model, where the magnetospheric part of the macro-parameters involved in the data-binning process (Sym-H index and its trend parameter) are replaced by their solar wind-based analogs obtained using the Burton-McPherron-Russell approach.

  9. Sloshing motion dynamics of a free surface in the draft tube cone of a Francis turbine operating in synchronous condenser mode

    Science.gov (United States)

    Vagnoni, Elena; Andolfatto, Loïc; Favrel, Arthur; Avellan, François

    2016-11-01

    The penetration of the electrical grid by intermittent renewable energy sources induces grid fluctuations which must be compensated in order to guarantee the stability of the grid. Hydropower plants can supply reactive power to ensure the grid stabilization by operating in condenser mode. In this operating mode, the turbine operates with the tail water depressed to let the runner spin in air to reduce the power consumption. Pressurized air is injected in the draft tube cone to maintain the water level below the runner and this induces air-water interaction phenomena which cause important power losses. Flow visualization and pressure fluctuation measurements are performed in a reduced scale physical model of a Francis turbine operating in condenser mode to investigate the dynamics of the air-water interaction in the draft tube cone which causes the sloshing motion of the free surface. An image post-processing method is developed, enabling a quantitative description of the sloshing motion. The latter depends on the Froude number. By increasing the value of the Froude number, the amplitude of the sloshing motion decreases, as well as the amplitude of the pressure fluctuations. The frequency of the sloshing motion corresponds to the first natural frequency of the water volume.

  10. Numerical Study of the Dynamic Response of Heat and Mass Transfer to Operation Mode Switching of a Unitized Regenerative Fuel Cell

    Directory of Open Access Journals (Sweden)

    Hong Xiao

    2016-12-01

    Full Text Available Knowledge concerning the complicated changes of mass and heat transfer is desired to improve the performance and durability of unitized regenerative fuel cells (URFCs. In this study, a transient, non-isothermal, single-phase, and multi-physics mathematical model for a URFC based on the proton exchange membrane is generated to investigate transient responses in the process of operation mode switching from fuel cell (FC to electrolysis cell (EC. Various heat generation mechanisms, including Joule heat, reaction heat, and the heat attributed to activation polarizations, have been considered in the transient model coupled with electrochemical reaction and mass transfer in porous electrodes. The polarization curves of the steady-state models are validated by experimental data in the literatures. Numerical results reveal that current density, gas mass fractions, and temperature suddenly change with the sudden change of operating voltage in the mode switching process. The response time of temperature is longer than that of current density and gas mass fractions. In both FC and EC modes, the cell temperature and gradient of gas mass fraction in the oxygen side are larger than that in the hydrogen side. The temperature difference of the entire cell is less than 1.5 K. The highest temperature appears at oxygen-side catalyst layer under the FC mode and at membrane under a more stable EC mode. The cell is exothermic all the time. These dynamic responses and phenomena have important implications for heat analysis and provide proven guidelines for the improvement of URFCs mode switching.

  11. Development of STEP-NC Adaptor for Advanced Web Manufacturing System

    Science.gov (United States)

    Ajay Konapala, Mr.; Koona, Ramji, Dr.

    2017-08-01

    Information systems play a key role in the modern era of Information Technology. Rapid developments in IT & global competition calls for many changes in basic CAD/CAM/CAPP/CNC manufacturing chain of operations. ‘STEP-NC’ an enhancement to STEP for operating CNC machines, creating new opportunities for collaborative, concurrent, adaptive works across the manufacturing chain of operations. Schemas and data models defined by ISO14649 in liaison with ISO10303 standards made STEP-NC file rich with feature based, rather than mere point to point information of G/M Code format. But one needs to have a suitable information system to understand and modify these files. Various STEP-NC information systems are reviewed to understand the suitability of STEP-NC for web manufacturing. Present work also deals with the development of an adaptor which imports STEP-NC file, organizes its information, allowing modifications to entity values and finally generates a new STEP-NC file to export. The system is designed and developed to work on web to avail additional benefits through the web and also to be part of a proposed ‘Web based STEP-NC manufacturing platform’ which is under development and explained as future scope.

  12. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode or/and with gas amplification

    International Nuclear Information System (INIS)

    Charpak, G; Benaben, P; Breuil, P; Peskov, V

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are attractive due to their simplicity and low cost and are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and so on. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification which potentially offers the highest possible sensitivity in applications like alpha particle detection or high energy X-ray photon or electron detection. To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of one (pulse ionization chamber). This detector was readout by a custom made wide -band charge sensitive amplifier able to deal with slow induced signals generated by slow motion of negative and positive ions. The multiwire detector was able to detect alpha particles with an efficiency close to 22%. The second type of an alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10 4 ). This detector can also operate in a cascaded mode or being combined with other detectors, for example with MICROMEGAS. This detector was readout by a conventional charge -sensitive amplifier and was able to detect alpha particles with 100% efficiency. This detector could also detect X-ray photons or fast electrons. A detailed comparison between these two detectors is given as well as a comparison with commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible applications of these new detectors is alpha particle background monitors which, due to their low cost can find wide application not only in houses, but

  13. Analysis of hybrid mode-locking of two-section quantum dot lasers operating at 1.5 microm.

    Science.gov (United States)

    Heck, Martijn J R; Salumbides, Edcel J; Renault, Amandine; Bente, Erwin A J M; Oei, Yok-Siang; Smit, Meint K; van Veldhoven, René; Nötzel, Richard; Eikema, Kjeld S E; Ubachs, Wim

    2009-09-28

    For the first time a detailed study of hybrid mode-locking in two-section InAs/InP quantum dot Fabry-Pérot-type lasers is presented. The output pulses have a typical upchirp of approximately 8 ps/nm, leading to very elongated pulses. The mechanism leading to this typical pulse shape and the phase noise is investigated by detailed radio-frequency and optical spectral studies as well as time-domain studies. The pulse shaping mechanism in these lasers is found to be fundamentally different than the mechanism observed in conventional mode-locked laser diodes, based on quantum well gain or bulk material.

  14. Flexible Control of Small Wind Turbines With Grid Failure Detection Operating in Stand-Alone and Grid-Connected Mode

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede

    2004-01-01

    nonlinear load and excess or deficit of generated power. Grid-connection mode with current control is also enabled for the case of isolated local grid involving other dispersed power generators such as other wind turbines or diesel generators. A novel automatic mode switch method based on a phase......-to-back power conversion configuration is chosen where the generator converter uses a built-in standard flux vector control to control the speed of the turbine shaft while the grid-side converter uses a standard pulse-width modulation active rectifier control strategy implemented in a DSP controller. The design...

  15. MOPABA-H2 - Computer code for calculation of hydrogen generation and distribution in the equipment of power plants with WWER type reactors in design modes of operation

    International Nuclear Information System (INIS)

    Arkhipov, O.P.; Kharitonov, Yu.V.; Shumskiy, A.M.; Kabakchi, S.A.

    2002-01-01

    With the aim of ensuring the hydrogen explosive-proof situation in the reactor plant, a complex of scientific-and-research work was carried out including the following: revealing the mechanisms of generation and release of hydrogen in the primary equipment components under design operation modes of the reactor plant with WWER; development of calculation procedure and computer code MOPABA-H2 enabling to determine the hydrogen content in RP equipment components under design operation modes. In the process of procedure development it was found out that the calculation of hydrogen content in the plant equipment requires development of the following main mathematical models: radiochemical processes in the primary coolant which has impurities and added special reagents; absorption of the core ionizing radiation by the coolant; steam-zirconium reaction (during design-basis accident of LOCA type); coolant mass transfer over the reactor plant equipment including transition of the phase boundary by the components of the coolant. (author)

  16. Optimal hysteretic control for a B M A P / S M / 1 / N queue with two operation modes

    Directory of Open Access Journals (Sweden)

    Dudin Alexander N.

    1999-01-01

    Full Text Available We consider B M A P / S M / 1 type queueing system with finite buffer of size N . The system has two operation modes, which are characterized by the matrix generating function of B M A P -input, the kernel of the semi-Markovian service process, and utilization cost. An algorithm for determining the optimal hysteresis strategy is presented.

  17. Single-mode distributed feedback laser operation with no dependence on the morphology of the gain medium

    Energy Technology Data Exchange (ETDEWEB)

    Umar, Muhammad [Department of Energy Systems Research, Ajou University, Suwon (Korea, Republic of); Min, Kyungtaek [Department of Energy Systems Research, Ajou University, Suwon (Korea, Republic of); Inter-university Semiconductor Research Center, Seoul National University (Korea, Republic of); Jeon, Heonsu [Department of Physics and Astronomy, Seoul National University (Korea, Republic of); Kim, Sunghwan [Department of Energy Systems Research, Ajou University, Suwon (Korea, Republic of); Department of Physics, Ajou University, Suwon (Korea, Republic of)

    2017-06-15

    Organic distributed feedback (DFB) lasers can be useful photonic tools for biological applications where the roles of organic materials are important, because highly coherent single mode emission with broad tuning range can be obtained. However, the formulaic structures of organic lasers, and the uses of gain media as resonators themselves, are not suitable for inducing laser emission from irregular shaped gain media, such as dye-staining cells and tissues. Here, we report a reusable photonic template comprising an exceedingly thin and discrete titanium dioxide (TiO{sub 2}) layer on a one-dimensional (1D) quartz grating to induce single mode DFB lasing from a variety of states of optical gain media. Using the same template, the external gain media of optically thick and thin casted film, liquid, and a free-standing thick film reveal single mode lasing with reliable performance. Numerical simulations demonstrate that the 25-nm thick TiO{sub 2} disconnected grating lines support a spatially confined DFB mode in the vertical direction, even under no index difference between superstrate and substrate. Additionally, not using the typical waveguide gain layer promises high sensitivity and detection limit in refractometric sensing. These results suggest that the photonic structure may serve as a versatile sensing platform for bioapplications. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Measurement of highly enriched uranium metal buttons with the high-level neutron coincidence counter operating in the active mode

    International Nuclear Information System (INIS)

    Foley, J.E.

    1980-10-01

    The portable High-Level Neutron Coincidence Counter is used in the active mode with the addition of AmLi neutron sources to assay the 235 U content of highly enriched metal pieces or buttons. It is concluded that the portable instrument is a practical instrument for assaying uranium metal buttons with masses in the range 1.5 to 4 kg

  19. The Thermal State Computational Research of the Low-Thrust Oxygen-Methane Gaseous-Propellant Rocket Engine in the Pulse Mode of Operation

    Directory of Open Access Journals (Sweden)

    O. A. Vorozheeva

    2014-01-01

    Full Text Available Currently promising development direction of space propulsion engineering is to use, as spacecraft controls, low-thrust rocket engines (RDTM on clean fuels, such as oxygen-methane. Modern RDTM are characterized by a lack regenerative cooling and pulse mode of operation, during which there is accumulation of heat energy to lead to the high thermal stress of RDTM structural elements. To get an idea about the thermal state of its elements, which further will reduce the number of fire tests is therefore necessary in the development phase of a new product. Accordingly, the aim of this work is the mathematical modeling and computational study of the thermal state of gaseous oxygen-methane propellant RDMT operating in pulse mode.In this paper we consider a model RDTM working on gaseous propellants oxygen-methane in pulse mode.To calculate the temperature field of the chamber wall of model RDMT under consideration is used the mathematical model of non-stationary heat conduction in a two-dimensional axisymmetric formulation that takes into account both the axial heat leakages and the nonstationary processes occurring inside the chamber during pulse operation of RDMT.As a result of numerical study of the thermal state of model RDMT, are obtained the temperature fields during engine operation based on convective, conductive, and radiative mechanisms of heat transfer from the combustion products to the wall.It is shown that the elements of flanges of combustion chamber of model RDMT act as heat sinks structural elements. Temperatures in the wall of the combustion chamber during the engine mode of operation are considered relatively low.Raised temperatures can also occur in the mixing head in the feeding area of the oxidant into the combustion chamber.During engine operation in the area forming the critical section, there is an intensive heating of a wall, which can result in its melting, which in turn will increase the minimum nozzle throat area and hence

  20. Stable TEM00-mode Nd:YAG solar laser operation by a twisted fused silica light-guide

    Science.gov (United States)

    Bouadjemine, R.; Liang, D.; Almeida, J.; Mehellou, S.; Vistas, C. R.; Kellou, A.; Guillot, E.

    2017-12-01

    To improve the output beam stability of a TEM00-mode solar-pumped laser, a twisted fused silica light-guide was used to achieve uniform pumping along a 3 mm diameter and 50 mm length Nd:YAG rod. The concentrated solar power at the focal spot of a primary parabolic mirror with 1.18 m2 effective collection area was efficiently coupled to the entrance aperture of a 2D-CPC/2V-shaped pump cavity, within which the thin laser rod was pumped. Optimum solar laser design parameters were found through ZEMAX© non-sequential ray-tracing and LASCAD© laser cavity analysis codes. 2.3 W continuous-wave TEM00-mode 1064 nm laser power was measured, corresponding to 1.96 W/m2 collection efficiency and 2.2 W laser beam brightness figure of merit. Excellent TEM00-mode laser beam profile at M2 ≤ 1.05 and very good output power stability of less than 1.6% were achieved. Heliostat orientation error dependent laser power variation was considerably less than previous solar laser pumping schemes.

  1. Thermal load distribution on the ALT-II limiter of TEXTOR-94 during RI mode operation and during disruptions

    International Nuclear Information System (INIS)

    Finken, K.H.; Denner, T.; Mank, G.

    2000-01-01

    Thermographic measurements using an IR scanner have been performed at the pump limiter ALT-II of TEXTOR-94 during RI mode discharges and during disruptions. The measurements on the RI mode discharges were done to complete the TEXTOR database which had shown a structured decay pattern of the deposited power. It was found that the underlying radial heat flux can be described by two exponential decay functions. This structure, which generates an unexpected heat component close to the tangent line, has been observed in all discharge conditions including the RI mode. During disruptions, the heat is released in short pulses with a typical duration of 0.01-0.1 ms. The radial decay length of these pulses has a similar shape to the heat flux during normal discharges: it consists again of a strong component close to the tangent line with a radial decay length of 2-5 mm and probably one with a decay length of the order of 1 cm. The heat is released at the time when the edge electron temperature of the plasma drops, when intense hydrogen and carbon fluxes occur near the walls, and when electrical currents in the limiter blades are excited. In a tentative interpretation, the temporal and spatial structure of the heat pulse is attributed to the presence and growth of a laminar zone at the plasma edge, which is connected with the ergodization of the plasma edge during a disruption. (author)

  2. Study of modes of operation water system movement with bypass system towers cooling by Ecosimpro; Estudio de modos de operacion del sistema de agua de circulacion con sistema de bypass de las torres de refrigeracion mediante Ecosimpro

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, J.; Molina, M. C.; Gavilan, C.; Molina, J. J.

    2013-07-01

    The present paper is based on the thermodynamic study of the system of water circulation of the Central Nuclear de Cofrentes. The objective of the study is the operation of the system through different modes of operation, with the aim of analyze the impact of these modes over the operation of the same. For a complete analysis, it has created a computer model of the system through the EcosimPro software, which is the simulation of the operation modes system and through the results, is the analysis of their feasibility.

  3. Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode

    CERN Document Server

    Kramer, Thomas; Borburgh, Jan; Ducimetière, Laurent; Feliciano, Luis; Ferrero Colomo, Alvaro; Goddard, Brennan; Sermeus, Luc

    2016-01-01

    Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying...

  4. Low-timing-jitter, stretched-pulse passively mode-locked fiber laser with tunable repetition rate and high operation stability

    International Nuclear Information System (INIS)

    Liu, Yuanshan; Zhang, Jian-Guo; Chen, Guofu; Zhao, Wei; Bai, Jing

    2010-01-01

    We design a low-timing-jitter, repetition-rate-tunable, stretched-pulse passively mode-locked fiber laser by using a nonlinear amplifying loop mirror (NALM), a semiconductor saturable absorber mirror (SESAM), and a tunable optical delay line in the laser configuration. Low-timing-jitter optical pulses are stably produced when a SESAM and a 0.16 m dispersion compensation fiber are employed in the laser cavity. By inserting a tunable optical delay line between NALM and SESAM, the variable repetition-rate operation of a self-starting, passively mode-locked fiber laser is successfully demonstrated over a range from 49.65 to 50.47 MHz. The experimental results show that the newly designed fiber laser can maintain the mode locking at the pumping power of 160 mW to stably generate periodic optical pulses with width less than 170 fs and timing jitter lower than 75 fs in the 1.55 µm wavelength region, when the fundamental repetition rate of the laser is continuously tuned between 49.65 and 50.47 MHz. Moreover, this fiber laser has a feature of turn-key operation with high repeatability of its fundamental repetition rate in practice

  5. Selectivity of the gas sensor based on the 50%In2O3-50%Ga2O3 thin film in dynamic mode of operation

    Science.gov (United States)

    Demin, I. E.; Kozlov, A. G.

    2018-01-01

    The article considers the gas sensor with the sensitive layer based on the 50%In2O3 -50%Ga2O3 thin film. The temperature and concentration dependencies of gas-induced resistance response of this sensor and the dynamical dependencies of its resistance response on the test gases in air are investigated. The test gases were ethanol, acetone, ammonia and liquefied petroleum gas. The information parameters of the sensor in the dynamical mode of operation were considered to improve its selectivity. The presented results show that the selectivity of the sensor in this mode may be improved by using the following information parameters: gas-induced resistance response in steady state, activation energy of the response and pre-exponential factor of the temperature dependence of the response time constant.

  6. Research on the Operation Mode of Intelligent-town Energy Internet Based on Source-Load Interaction

    Science.gov (United States)

    Li, Hao; Li, Wen; Miao, Bo; Li, Bin; Liu, Chang; Lv, Zhipeng

    2018-01-01

    On the background of the rise of intelligence and the increasing deepening of “Internet +”application, the energy internet has become the focus of the energy research field. This paper, based on the fundamental understanding on the energy internet of the intelligent town, discusses the mode of energy supply in the source-load interactive region, and gives an in-depth study on the output characteristics of the energy supply side and the load characteristics of the demand side, so as to derive the law of energy-load interaction of the intelligent-town energy internet.

  7. EnviroAtlas - Durham, NC - Demo (Parent)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Durham, NC EnviroAtlas Area. The block groups are from the US Census Bureau and are included/excluded based on...

  8. Analysis Of The Heat Exchanger Capability At One Line Cooling System Operation Mode Of The RSG-GAS

    International Nuclear Information System (INIS)

    Dibyo, Sukmanto; Kuntoro, Iman

    2000-01-01

    In the frame of minimizing the operation lost of the RSG-GAS reactor, operation using one line cooling system at certain power range is being evaluated. Analysis the performance of cooling system for determining maximum power should be carried out. Analysis was carried out based on heat exchanger calculation using actual operation data. Constraints imposed to the analysis are that inlet cooling system to the reactor core shall be less than 42 o C. The result shows that by using one line of primary and secondary coolant flow of 1780 m exp. 3/hr and 2000 m 3 /hr and secondary coolant temperature from the cooling tower of 38 o C, the primary coolant to the core will be reach 42 o C if reactor operated at power of 16 MW

  9. Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations

    OpenAIRE

    Chen, T; Zhao, H; Xie, H; He, B

    2014-01-01

    © IMechE 2014. Controlled auto-ignition, also known as homogeneous charge compression ignition, has been the subject of extensive research because of their ability to provide simultaneous reductions in fuel consumption and NOx emissions from a gasoline engine. However, due to its limited operation range, switching between controlled auto-ignition and spark ignition combustion is needed to cover the complete operating range of a gasoline engine for passenger car applications. Previous research...

  10. Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Takahashi, Masato; Maeda, Hideaki; Ebisawa, Yusuke; Tennmei, Konosuke; Yanagisawa, Yoshinori; Nakagome, Hideki; Hosono, Masami; Takasugi, Kenji; Hase, Takashi; Miyazaki, Takayoshi; Fujito, Teruaki; Kiyoshi, Tsukasa; Yamazaki, Toshio

    2012-01-01

    Achieving a higher magnetic field is important for solid-state nuclear magnetic resonance (NMR). But a conventional low temperature superconducting (LTS) magnet cannot exceed 1 GHz (23.5 T) due to the critical magnetic field. Thus, we started a project to replace the Nb 3 Sn innermost coil of an existing 920 MHz NMR (21.6 T) with a Bi-2223 high temperature superconducting (HTS) innermost coil. Unfortunately, the HTS magnet cannot be operated in persistent current mode; an external dc power supply is required to operate the NMR magnet, causing magnetic field fluctuations. These fluctuations can be stabilized by a field-frequency lock system based on an external NMR detection coil. We demonstrate here such a field-frequency lock system in a 500 MHz LTS NMR magnet operated in an external current mode. The system uses a 7 Li sample in a microcoil as external NMR detection system. The required field compensation is calculated from the frequency of the FID as measured with a frequency counter. The system detects the FID signal, determining the FID frequency, and calculates the required compensation coil current to stabilize the sample magnetic field. The magnetic field was stabilized at 0.05 ppm/3 h for magnetic field fluctuations of around 10 ppm. This method is especially effective for a magnet with large magnetic field fluctuations. The magnetic field of the compensation coil is relatively inhomogeneous in these cases and the inhomogeneity of the compensation coil can be taken into account.

  11. Hardware Development of a Laboratory-Scale Microgrid Phase 1--Single Inverter in Island Mode Operation: Base Year Report, December 2000 -- November 2001

    Energy Technology Data Exchange (ETDEWEB)

    Venkataramanan, G.; Illindala, M. S.; Houle, C.; Lasseter, R. H.

    2002-11-01

    This report summarizes the activities of the first year of a three-year project to develop control software for micro-source distributed generation systems. The focus of this phase was on internal energy storage requirements, the modification of an off-the-shelf motor drive system inverter to supply utility-grade ac power, and a single inverter system operating in island mode. The report provides a methodology for determining battery energy storage requirements, a method for converting a motor drive inverter into a utility-grade inverter, and typical characteristics and test results of using such an inverter in a complex load environment.

  12. A Gamma Scanner Using a Ge(Li) Semi-Conductor Detector, with the Possibility of Operation in the Anti-Coincidence Mode

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Blackadder, W H

    1970-04-15

    A fuel element transport flask has been modified as a facility for gamma scanning irradiated fuel elements up to a length of 75 cm. By means of a Ge(Li) semi-conductor detector, satisfactory activity profiles along the specimens have been obtained, permitting the location of individual fuel pellets. An annular plastic detector surrounding the Ge(Li) detector allows operation of the spectrometer in the anti-coincidence mode, and reduction of the Compton continuum by about 50% has been obtained.

  13. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    OpenAIRE

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-01-01

    Measurements of ion energy distribution are performed in the accelerated plasma of a coaxial electromagnetic plasma gun operating in a gas-puff mode at relatively low discharge energy (900 J) and discharge potential (4 kV). The measurements are made using a Thomson-type mass and energy spectrometer with a gated microchannel plate and phosphor screen as the ion sensor. The parabolic ion trajectories are captured from the sensor screen with an intensified charge-coupled detector camera. The spe...

  14. Implementation of an adaptive controller for the startup and steady-state running of a biomethanation process operated in the CSTR mode.

    Science.gov (United States)

    Renard, P; Van Breusegem, V; Nguyen, M T; Naveau, H; Nyns, E J

    1991-10-20

    An adaptive control algorithm has been implemented on a biomethanation process to maintain propionate concentration, a stable variable, at a given low value, by steering the dilution rate. It was thereby expected to ensure the stability of the process during the startup and during steady-state running with an acceptable performance. The methane pilot reactor was operated in the completely mixed, once-through mode and computer-controlled during 161 days. The results yielded the real-life validation of the adaptive control algorithm, and documented the stability and acceptable performance expected.

  15. A Gamma Scanner Using a Ge(Li) Semi-Conductor Detector, with the Possibility of Operation in the Anti-Coincidence Mode

    International Nuclear Information System (INIS)

    Forsyth, R.S.; Blackadder, W.H.

    1970-04-01

    A fuel element transport flask has been modified as a facility for gamma scanning irradiated fuel elements up to a length of 75 cm. By means of a Ge(Li) semi-conductor detector, satisfactory activity profiles along the specimens have been obtained, permitting the location of individual fuel pellets. An annular plastic detector surrounding the Ge(Li) detector allows operation of the spectrometer in the anti-coincidence mode, and reduction of the Compton continuum by about 50% has been obtained

  16. Beam dynamics studies of the photo-injector in low-charge operation mode for the ERL test facility at IHEP

    International Nuclear Information System (INIS)

    Jiao Yi; Xiao Ouzheng

    2014-01-01

    The energy recovery linac test facility (ERL-TF), which is a compact ERL-FEL (free electron laser) two-purpose machine, was proposed at the Institute of High Energy Physics, Beijing. As one important component of the ERL-TF, the photo-injector that started with a photocathode direct-current gun has been designed. In this paper, optimization of the injector beam dynamics in low-charge operation mode is performed with iterative scans using Impact-T. In addition, the dependencies between the optimized beam quality and the initial offset at cathode and element parameters are investigated. The tolerance of alignment and rotation errors is also analyzed. (authors)

  17. Scale-up of counter-current chromatography: demonstration of predictable isocratic and quasi-continuous operating modes from the test tube to pilot/process scale.

    Science.gov (United States)

    Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

    2009-12-11

    Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18 L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction.

  18. Time-resolved soft x-ray absorption setup using multi-bunch operation modes at synchrotrons

    International Nuclear Information System (INIS)

    Stebel, L.; Sigalotti, P.; Ressel, B.; Cautero, G.; Malvestuto, M.; Capogrosso, V.; Bondino, F.; Magnano, E.; Parmigiani, F.

    2011-01-01

    Here, we report on a novel experimental apparatus for performing time-resolved soft x-ray absorption spectroscopy in the sub-ns time scale using non-hybrid multi-bunch mode synchrotron radiation. The present setup is based on a variable repetition rate Ti:sapphire laser (pump pulse) synchronized with the ∼500 MHz x-ray synchrotron radiation bunches and on a detection system that discriminates and singles out the significant x-ray photon pulses by means of a custom made photon counting unit. The whole setup has been validated by measuring the time evolution of the L 3 absorption edge during the melting and the solidification of a Ge single crystal irradiated by an intense ultrafast laser pulse. These results pave the way for performing synchrotron time-resolved experiments in the sub-ns time domain with variable repetition rate exploiting the full flux of the synchrotron radiation.

  19. H-mode WEST tungsten divertor operation: deuterium and nitrogen seeded simulations with SOLEDGE2D-EIRENE

    Directory of Open Access Journals (Sweden)

    G. Ciraolo

    2017-08-01

    Full Text Available Simulations of WEST H-mode divertor scenarios have been performed with SOLEDGE2D-EIRENE edge plasma transport code, both for pure deuterium and nitrogen seeded discharge. In the pure deuterium case, a target heat flux of 8 MW/m2 is reached, but misalignment between heat and the particle outflux yields 50 eV plasma temperature at the target plates. With nitrogen seeding, the heat and particle outflux are observed to be aligned so that lower plasma temperatures at the target plates are achieved together with the required high heat fluxes. This change in heat and particle outflux alignment is analysed with respect to the role of divertor geometry and the impact of vertical vs horizontal target plates on neutrals spreading.

  20. MOST-7 program for calculation of nonstationary operation modes of the nuclear steam generating plant with WWER

    International Nuclear Information System (INIS)

    Mysenkov, A.I.

    1979-01-01

    The MOST-7 program intended for calculating nonstationary emergency models of a nuclear steam generating plant (NSGP) with a WWER reactor is considered in detail. The program consists of the main MOST-7 subprogram, two main subprograms and 98 subprograms-functions. The MOST-7 program is written in the FORTRAN language and realized at the BESM-6 computer. Program storage capacity in the BESM-6 amounts to 73400 words. Primary information input into the program is carried out by means of information input operator from punched cards and DATA operator. Parameter lists, introduced both from punched cards and by means of DATA operator are tabulated. The procedure of calculational result output into printing and plotting devices is considered. Given is an example of calculating the nonstationary process, related to the loss of power in six main circulating pumps for NSGP with the WWER-440 reactor

  1. Thermal Optimized Operation of the Single-Phase Full-Bridge PV Inverter under Low Voltage Ride-Through Mode

    DEFF Research Database (Denmark)

    Wang, Huai; Yang, Yongheng; Blaabjerg, Frede

    2013-01-01

    The efficiency of 98% has been reported on transformer-less photovoltaic (PV) inverters and the penetration of grid-connected PV systems is booming as well. In the future, the PV systems are expected to contribute to the grid stability by means of low voltage ride-through operation and grid suppo...

  2. Ultrafiltration (UF Pilot Plant for Municipal Wastewater Reuse in Agriculture: Impact of the Operation Mode on Process Performance

    Directory of Open Access Journals (Sweden)

    Dario Falsanisi

    2010-11-01

    Full Text Available Following increasing interest in the use of UltraFiltration (UF membrane processes as an alternative advanced disinfection technique, the performance of a UF pilot plant was investigated under two opposite operating conditions (“stressed operating condition” versus “conventional operating condition”. The results indicate that for both conditions, the reclaimed effluent complied with the Italian regulations for unrestricted wastewater reuse (i.e., Total Suspended Solids (TSS < 10 mg/L; Chemical Oxygen Demand (COD < 100 mg/L and Escherichia coli < 10 CFU/100 mL. On the other hand, when compared with the Title 22 of the California Wastewater Reclamation Criteria, only the effluent produced under the “conventional operating condition” met the stipulated water quality standards (i.e., TSS and turbidity undetectable and total coliforms < 2.2 CFU/100 mL. It should be noted that, in spite of the nominal cut-off size, total coliforms breakthrough was indeed occasionally observed. A localized membrane pore micro-enlargement mechanism was hypothesized to explain the total coliforms propagation in the ultrafiltered effluent, as monitoring of the membrane permeability and transmembrane pressure highlighted that gel/cake formation had only a minor contribution to the overall membrane fouling mechanism with respect to pore plugging and pore narrowing mechanisms.

  3. Effects of SF$_{6}$ on the avalanche mode operation of a real-sized double-gap resistive plate chamber for the Compact Muon Solenoid experiment

    CERN Document Server

    Ahn Sung Hwan; Hong, B; Hong, S J; Ito, M; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K B; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S; Kang, T I

    2005-01-01

    We present the design and the test, results for a real-sized prototype resistive plate chamber by using cosmic-ray muons for the forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). In particular, we investigate the effects of adding SF/sub 6/ to the gas mixture for the avalanche mode operation of a resistive plate chamber. A small fraction of SF/sub 6/ is very effective in suppressing streamer signals in a resistive plate chamber. The shapes of the muon detection efficiency and the muon cluster size remain similar, but are shifted to higher operating voltage by SF/sub 6/. The noise cluster rate and size are not influenced by SF/sub 6/.

  4. Operating Modes and Cooling Capabilities of the 3-Stage ADR Developed for the Soft-X-Ray Spectrometer Instrument on Astro-H

    Science.gov (United States)

    Shirron, Peter J.; Kimball, Mark O.; James, Bryan L.; Muench, Theo; DiPirro, Michael J.; Letmate, Richard V.; Sampson, Michael A.; Bialas, Tom G.; Sneiderman, Gary A.; Porter, Frederick S.; hide

    2015-01-01

    A 3-stage adiabatic demagnetization refrigerator (ADR) is used on the Soft X-ray Spectrometer instrument on Astro-H to cool a 6x6 array of x-ray microcalorimeters to 50 mK. The ADR is supported by a cryogenic system consisting of a superfluid helium tank, a 4.5 K Joule-Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and cool radiation shields within the cryostat. The ADR is configured so that it can use either the liquid helium or the JT cryocooler as its heat sink, giving the instrument an unusual degree of tolerance for component failures or degradation in the cryogenic system. The flight detector assembly, ADR and dewar were integrated into the flight dewar in early 2014, and have since been extensively characterized and calibrated. This paper summarizes the operation and performance of the ADR in all of its operating modes

  5. Research on operation mode and risk of crowd-funding in China%中国股权众筹运作模式及风险研究

    Institute of Scientific and Technical Information of China (English)

    李倩; 王璐瑶

    2015-01-01

    近年来,互联网金融凭借着运营风险低、交易成本低、运作效率高的特点成为各地经济发展的重要手段,为世界金融发展注入了新的活力. 从分析股权众筹概念入手,研究国内股权众筹运作模式的发展和创新,采用二元Logit模型分析"领投+跟投"模式对股权众筹运营的促进作用,同时从法律风险和项目运营风险两方面对股权众筹运作模式进行风险分析并提出相应的防范措施,以便于更好地保护投资者的利益,促进股权众筹模式的发展.%In recent years, internet finance has become an important means of local economic development owing to its lower operational risk, lower transaction costs and higher efficiency, which has injected new vitality into the world financial development. Starting from the analysis of the definition of stock crowd-funding, the development and innovation of the operation mode of stock crowd-funding are researched. The binary Logit model is used to analyze the promoting effect of the mode of "leader+follower" on the operation of stock crowd-funding. At the same time, the risk analysis is carried out from the perspectives of legal risk and project operational risk, and the corresponding preventive measures are proposed, so as to better protect the interests of investors, and promote the development of stock crowd-funding.

  6. Characterization of performance-emission indices of a diesel engine using ANFIS operating in dual-fuel mode with LPG

    Science.gov (United States)

    Chakraborty, Amitav; Roy, Sumit; Banerjee, Rahul

    2018-03-01

    This experimental work highlights the inherent capability of an adaptive-neuro fuzzy inference system (ANFIS) based model to act as a robust system identification tool (SIT) in prognosticating the performance and emission parameters of an existing diesel engine running of diesel-LPG dual fuel mode. The developed model proved its adeptness by successfully harnessing the effects of the input parameters of load, injection duration and LPG energy share on output parameters of BSFCEQ, BTE, NOX, SOOT, CO and HC. Successive evaluation of the ANFIS model, revealed high levels of resemblance with the already forecasted ANN results for the same input parameters and it was evident that similar to ANN, ANFIS also has the innate ability to act as a robust SIT. The ANFIS predicted data harmonized the experimental data with high overall accuracy. The correlation coefficient (R) values are stretched in between 0.99207 to 0.999988. The mean absolute percentage error (MAPE) tallies were recorded in the range of 0.02-0.173% with the root mean square errors (RMSE) in acceptable margins. Hence the developed model is capable of emulating the actual engine parameters with commendable ranges of accuracy, which in turn would act as a robust prediction platform in the future domains of optimization.

  7. A discrete model of the development and relaxation of a local microbreakdown in silicon avalanche photodiodes operating in the Geiger mode

    International Nuclear Information System (INIS)

    Vanyushin, I. V.; Gergel, V. A.; Gontar', V. M.; Zimoglyad, V. A.; Tishin, Yu. I.; Kholodnov, V. A.; Shcheleva, I. M.

    2007-01-01

    A new discrete theoretical model of the development and relaxation of a local microbreakdown in silicon avalanche photodiodes operating in the Geiger mode is developed. It is shown that the spreading resistance in the substrate profoundly affects both the amplitude of a single-photon electrical pulse and the possibility of attaining the steady-state form of the avalanche breakdown excluding the Geiger mode of the photodiode's operation. The model is employed to interpret the experimental data obtained using test single-photon cells of avalanche photodiodes fabricated on the basis of the 0.25-μm silicon technology with the use of deep implantation to form the region of avalanche multiplication for the charge carriers. Excellent functional properties of the studied type of the single-photon (Geiger) cell are noted. A typical amplitude characteristic of the cell for optical radiation with the wavelength λ = 0.56 μm in the irradiance range of 10 -3 -10 2 lx is presented; this characteristic indicates that the quantum efficiency of photoconversion is extremely high

  8. Dynamoelectric machine with a superconductive field winding that can operate in either a synchronous or an asynchronous mode

    International Nuclear Information System (INIS)

    Mole, C.J.; Haller, H.E. III.

    1977-01-01

    Two parallel magnetic flux paths are provided in a dynamoelectric machine having a superconductive field winding. A first, or main, magnetic flux path includes at least one area of nonferromagnetic or diamagnetic material. A second, or shunt, magnetic flux path prevents the relatively low frequency ac flux present during starting or asynchronous operation of the machine, when used as an ac motor, from penetrating the superconductive winding

  9. A Coupled Field Multiphysics Modeling Approach to Investigate RF MEMS Switch Failure Modes under Various Operational Conditions

    Directory of Open Access Journals (Sweden)

    Khaled Sadek

    2009-10-01

    Full Text Available In this paper, the reliability of capacitive shunt RF MEMS switches have been investigated using three dimensional (3D coupled multiphysics finite element (FE analysis. The coupled field analysis involved three consecutive multiphysics interactions. The first interaction is characterized as a two-way sequential electromagnetic (EM-thermal field coupling. The second interaction represented a one-way sequential thermal-structural field coupling. The third interaction portrayed a two-way sequential structural-electrostatic field coupling. An automated substructuring algorithm was utilized to reduce the computational cost of the complicated coupled multiphysics FE analysis. The results of the substructured FE model with coupled field analysis is shown to be in good agreement with the outcome of previously published experimental and numerical studies. The current numerical results indicate that the pull-in voltage and the buckling temperature of the RF switch are functions of the microfabrication residual stress state, the switch operational frequency and the surrounding packaging temperature. Furthermore, the current results point out that by introducing proper mechanical approaches such as corrugated switches and through-holes in the switch membrane, it is possible to achieve reliable pull-in voltages, at various operating temperatures. The performed analysis also shows that by controlling the mean and gradient residual stresses, generated during microfabrication, in conjunction with the proposed mechanical approaches, the power handling capability of RF MEMS switches can be increased, at a wide range of operational frequencies. These design features of RF MEMS switches are of particular importance in applications where a high RF power (frequencies above 10 GHz and large temperature variations are expected, such as in satellites and airplane condition monitoring.

  10. Enhanced efficiency in the excitation of higher modes for atomic force microscopy and mechanical sensors operated in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Penedo, M., E-mail: mapenedo@imm.cnm.csic.es; Hormeño, S.; Fernández-Martínez, I.; Luna, M.; Briones, F. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760 Tres Cantos, Madrid (Spain); Raman, A. [Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47904 (United States)

    2014-10-27

    Recent developments in dynamic Atomic Force Microscopy where several eigenmodes are simultaneously excited in liquid media are proving to be an excellent tool in biological studies. Despite its relevance, the search for a reliable, efficient, and strong cantilever excitation method is still in progress. Herein, we present a theoretical modeling and experimental results of different actuation methods compatible with the operation of Atomic Force Microscopy in liquid environments: ideal acoustic, homogeneously distributed force, distributed applied torque (MAC Mode™), photothermal and magnetostrictive excitation. From the analysis of the results, it can be concluded that magnetostriction is the strongest and most efficient technique for higher eigenmode excitation when using soft cantilevers in liquid media.

  11. Operation of a quantum dot in the finite-state machine mode: Single-electron dynamic memory

    Energy Technology Data Exchange (ETDEWEB)

    Klymenko, M. V. [Department of Chemistry, University of Liège, B4000 Liège (Belgium); Klein, M. [The Fritz Haber Center for Molecular Dynamics and the Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Levine, R. D. [The Fritz Haber Center for Molecular Dynamics and the Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095 (United States); Remacle, F., E-mail: fremacle@ulg.ac.be [Department of Chemistry, University of Liège, B4000 Liège (Belgium); The Fritz Haber Center for Molecular Dynamics and the Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

    2016-07-14

    A single electron dynamic memory is designed based on the non-equilibrium dynamics of charge states in electrostatically defined metallic quantum dots. Using the orthodox theory for computing the transfer rates and a master equation, we model the dynamical response of devices consisting of a charge sensor coupled to either a single and or a double quantum dot subjected to a pulsed gate voltage. We show that transition rates between charge states in metallic quantum dots are characterized by an asymmetry that can be controlled by the gate voltage. This effect is more pronounced when the switching between charge states corresponds to a Markovian process involving electron transport through a chain of several quantum dots. By simulating the dynamics of electron transport we demonstrate that the quantum box operates as a finite-state machine that can be addressed by choosing suitable shapes and switching rates of the gate pulses. We further show that writing times in the ns range and retention memory times six orders of magnitude longer, in the ms range, can be achieved on the double quantum dot system using experimentally feasible parameters, thereby demonstrating that the device can operate as a dynamic single electron memory.

  12. Operation of a quantum dot in the finite-state machine mode: Single-electron dynamic memory

    International Nuclear Information System (INIS)

    Klymenko, M. V.; Klein, M.; Levine, R. D.; Remacle, F.

    2016-01-01

    A single electron dynamic memory is designed based on the non-equilibrium dynamics of charge states in electrostatically defined metallic quantum dots. Using the orthodox theory for computing the transfer rates and a master equation, we model the dynamical response of devices consisting of a charge sensor coupled to either a single and or a double quantum dot subjected to a pulsed gate voltage. We show that transition rates between charge states in metallic quantum dots are characterized by an asymmetry that can be controlled by the gate voltage. This effect is more pronounced when the switching between charge states corresponds to a Markovian process involving electron transport through a chain of several quantum dots. By simulating the dynamics of electron transport we demonstrate that the quantum box operates as a finite-state machine that can be addressed by choosing suitable shapes and switching rates of the gate pulses. We further show that writing times in the ns range and retention memory times six orders of magnitude longer, in the ms range, can be achieved on the double quantum dot system using experimentally feasible parameters, thereby demonstrating that the device can operate as a dynamic single electron memory.

  13. Evaluation of Mixed-Mode Data-Link Communications for NextGen 4DT and Equivalent Visual Surface Operations

    Science.gov (United States)

    Prinzel, Lawrence J., III; Shelton, Kevin J.; Jones, Denise R.; Allamandola, Angela S.; Arthur, Jarvis, J., III; Bailey, Randall E.

    2010-01-01

    By 2025, U.S. air traffic is predicted to increase 3-fold and may strain the current air traffic management system, which may not be able to accommodate this growth. In response to this challenge, a revolutionary new concept has been proposed for U.S. aviation operations, termed the Next Generation Air Transportation System or NextGen. Many key capabilities are being identified to enable NextGen, including the use of data-link communications. Because NextGen represents a radically different approach to air traffic management and requires a dramatic shift in the tasks, roles, and responsibilities for the flight deck, there are numerous research issues and challenges that must be overcome to ensure a safe, sustainable air transportation system. Flight deck display and crew-vehicle interaction concepts are being developed that proactively investigate and overcome potential technology and safety barriers that might otherwise constrain the full realization of NextGen. The paper describes simulation research examining data-link communications during 4DT and equivalent visual surface operations.

  14. TMRBAR: a code to calculate plasma parameters for tandem-mirror reactors operating in the MARS mode

    International Nuclear Information System (INIS)

    Campbell, R.B.

    1983-01-01

    The purpose of this report is to document the plasma power balance model currently used by LLNL to calculate steady state operating points for tandem mirror reactors. The code developed from this model, TMRBAR, has been used to predict the performance and define supplementary heating requirements for drivers used in the Mirror Advanced Reactor Study (MARS) and for the Fusion Power Demonstration (FPD) study. The equations solved included particle and energy balance for central cell and end cell species, quasineutrality at several cardinal points in the end cell region, as well as calculations of volumes, densities and average energies based on given constraints of beta profiles and fusion power output. Alpha particle ash is treated self-consistently, but no other impurity species is treated

  15. Standard Practice for Exposure of Cover Materials for Solar Collectors to Natural Weathering Under Conditions Simulating Operational Mode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This practice provides a procedure for the exposure of cover materials for flat-plate solar collectors to the natural weather environment at temperatures that are elevated to approximate operating conditions. 1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials. 1.3 This practice does not apply to cover materials for evacuated collectors or photovoltaics. 1.4 The values stated in SI units are to be regarded as the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. A win-win marginal rent analysis for operator and consumer under battery leasing mode in China electric vehicle market

    International Nuclear Information System (INIS)

    Li Zhe; Ouyang Minggao

    2011-01-01

    Recently battery leasing has been introduced into the market by automobile manufacturers and power suppliers due to its potential to reduce the purchase cost of electric vehicles (EVs). However, the profit prospect of battery leasing is still uncertain. This paper takes the views of both the operators and consumers and calculates the 'win-win' marginal rent, which not only ensures the profitability of operators, but also allows consumers a lower expenditure than using Internal combustion engine vehicles (ICVs) and EVs with embedded batteries. Battery cost, vehicle weight, gasoline and electricity price, and the discount rate have impacts on the rent. Battery cost plays a dominant role and a battery cost >5 Yen /W h fails to enable the survival of battery leasing to all types of EVs. Battery leasing would be more competitive when focusing on heavier EVs. At least one of the three thresholds is required for the existence of rent pricing range for a 1000 kg EV: gasoline retail price >6 Yen /L, electricity price <0.6 Yen /kW h, or the discount rate <7%. Typically, the feasible battery rent range is 0.34-0.38 Yen /W h/year for a 1000 kg EV under the present battery cost 2 Yen /W h and China current gasoline and electricity prices. - Highlights: → Rent pricing for EV battery leasing must obey win-win rule for BLO and consumers. → Rent is affected by battery cost, vehicle weight, energy price and discount rate. → Battery cost plays dominant role for the BLO survival as described in '5-3-2' Law. → Heavier EVs are more suitable for battery leasing when battery cost is high. → The profitability of BLO is sensitive to the price of gasoline and electricity.

  17. Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, K. H.; Chen, X.; Garofalo, A. M.; Groebner, R. J.; Muscatello, C. M.; Osborne, T. H.; Petty, C. C.; Snyder, P. B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Barada, K.; Rhodes, T. L.; Zeng, L. [University of California-Los Angeles, Los Angeles, California 90024 (United States); Solomon, W. M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Yan, Z. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2016-05-15

    Recent experiments in DIII-D [J. L. Luxon et al., in Plasma Physics and Controlled Nuclear Fusion Research 1996 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net external torque input. Eliminating the ELM-induced heat bursts and controlling plasma stability at low rotation represent two of the great challenges for fusion energy. By exploiting edge turbulence in a novel manner, we achieved excellent tokamak performance, well above the H{sub 98y2} international tokamak energy confinement scaling (H{sub 98y2} = 1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggered in double null plasmas by ramping the injected torque to zero and then maintaining it there. This lowers E × B rotation shear in the plasma edge, allowing low-k, broadband, electromagnetic turbulence to increase. In the H-mode edge, a narrow transport barrier usually grows until MHD instability (a peeling ballooning mode) leads to the ELM heat burst. However, the increased turbulence reduces the pressure gradient, allowing the development of a broader and thus higher transport barrier. A 60% increase in pedestal pressure and 40% increase in energy confinement result. An increase in the E × B shearing rate inside of the edge pedestal is a key factor in the confinement increase. Strong double-null plasma shaping raises the threshold for the ELM instability, allowing the plasma to reach a transport-limited state near but below the explosive ELM stability boundary. The resulting plasmas have burning-plasma-relevant β{sub N} = 1.6–1.8 and run without the need for extra torque from 3D magnetic fields. To date, stationary conditions have been produced for 2 s or 12 energy confinement times, limited only by external hardware constraints

  18. Plasma erosion opening switch in the double-pulse operation mode of a high-current electron accelerator

    International Nuclear Information System (INIS)

    Isakov, I.F.; Lopatin, V.S.; Remnev, G.E.

    1987-01-01

    This paper reports the results of investigations of the operation of a fast current opening switch, with a 10/sup 13/-10/sup 16/ plasma density produced either by dielectric surface flashover or by explosive emission of graphite. A series of two pulses was applied to two diodes in parallel. The first pulse produced plasma in the first diode which closed that diode gap by the arrival time of the second pulse. The first, shorted, diode then acted as an erosion switch for the second pulse. A factor of 2.5-3 power multiplication was obtained under optimum conditions. The opening-switch resistance during the magnetic insulation phase, neglecting the electron losses between the switch and the generating diode, exceeded 100 Ω. The duration of the rapid opening phase was less than 5 ns under optimum conditions. This method of plasma production does not require external plasma sources, and permits a wide variation of plasma density, which in turn allows high inductor currents and stored energies

  19. Operation of a New Half-Bridge Gate Driver for Enhancement - Mode GaN FETs, Type LM5113, Over a Wide Temperature Range

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad

    2011-01-01

    A new commercial-off-the-shelf (COTS) gate driver designed to drive both the high-side and the low-side enhancement-mode GaN FETs, National Semiconductor's type LM5113, was evaluated for operation at temperatures beyond its recommended specified limits of -40 C to +125 C. The effects of limited thermal cycling under the extended test temperature, which ranged from -194 C to +150 C, on the operation of this chip as well as restart capability at the extreme cryogenic and hot temperatures were also investigated. The driver circuit was able to maintain good operation throughout the entire test regime between -194 C and +150 C without undergoing any major changes in its outputs signals and characteristics. The limited thermal cycling performed on the device also had no effect on its performance, and the driver chip was able to successfully restart at each of the extreme temperatures of -194 C and +150 C. The plastic packaging of this device was also not affected by either the short extreme temperature exposure or the limited thermal cycling. These preliminary results indicate that this new commercial-off-the-shelf (COTS) halfbridge eGaN FET driver integrated circuit has the potential for use in space exploration missions under extreme temperature environments. Further testing is planned under long-term cycling to assess the reliability of these parts and to determine their suitability for extended use in the harsh environments of space.

  20. Grating array systems having a plurality of gratings operative in a coherently additive mode and methods for making such grating array systems

    Science.gov (United States)

    Kessler, Terrance J [Mendon, NY; Bunkenburg, Joachim [Victor, NY; Huang, Hu [Pittsford, NY

    2007-02-13

    A plurality of gratings (G1, G2) are arranged together with a wavefront sensor, actuators, and feedback system to align the gratings in such a manner, that they operate like a single, large, monolithic grating. Sub-wavelength-scale movements in the mechanical mounting, due to environmental influences, are monitored by an interferometer (28), and compensated by precision actuators (16, 18, 20) that maintain the coherently additive mode. The actuators define the grating plane, and are positioned in response to the wavefronts from the gratings and a reference flat, thus producing the interferogram that contains the alignment information. Movement of the actuators is also in response to a diffraction-limited spot on the CCD (36) to which light diffracted from the gratings is focused. The actuator geometry is implemented to take advantage of the compensating nature of the degrees of freedom between gratings, reducing the number of necessary control variables.

  1. Nanomechanical microcantilever operated in vibration modes with use of RNA aptamer as receptor molecules for label-free detection of HCV helicase.

    Science.gov (United States)

    Hwang, Kyo Seon; Lee, Sang-Myung; Eom, Kilho; Lee, Jeong Hoon; Lee, Yoon-Sik; Park, Jung Ho; Yoon, Dae Sung; Kim, Tae Song

    2007-11-30

    We report the nanomechanical microcantilevers operated in vibration modes (oscillation) with use of RNA aptamers as receptor molecules for label-free detection of hepatitis C virus (HCV) helicase. The nanomechanical detection principle is that the ligand-receptor binding on the microcantilever surface induces the dynamic response change of microcantilevers. We implemented the label-free detection of HCV helicase in the low concentration as much as 100 pg/ml from measuring the dynamic response change of microcantilevers. Moreover, from the recent studies showing that the ligand-receptor binding generates the surface stress on the microcantilever, we estimate the surface stress, on the oscillating microcantilevers, induced by ligand-receptor binding, i.e. binding between HCV helicase and RNA aptamer. In this article, it is suggested that the oscillating microcantilevers with use of RNA aptamers as receptor molecules may enable one to implement the sensitive label-free detection of very small amount of small-scale proteins.

  2. Common Rail Direct Injection Mode of CI Engine Operation with Different Injection Strategies - A Method to Reduce Smoke and NOx Emissions Simultaneously

    Directory of Open Access Journals (Sweden)

    S. V. Khandal

    2018-03-01

    Full Text Available Compression ignition (CI engines are most efficient and robust prime movers used in transportation, power generation applications but suffer from the problems of higher level of exhaust smoke and NOx tailpipe emissions with increased use of fossil fuels. Alternative fuel that replaces diesel and at the same time that result in lower smoke and NOx emissions is presently needed. Therefore the main aim of this experimental study is to lower the smoke and NOx emissions and to use non edible oils that replace the diesel. For this locally available honge biodiesel (BHO and cotton seed biodiesel (BCO were selected as alternative fuels to power CI engine operated in common rail direct injection (CRDI mode. In the first part, optimum fuel injection timing (IT and injection pressure (IP for maximum engine brake thermal efficiency (BTE was obtained. In the second part, performance, combustion and emission characteristics of the CRDI engine was studied with two different fuel injectors having 6 and 7 holes each having 0.2 mm orifice diameter. The CRDI engine results obtained were compared with the baseline date reported. The combustion chamber (CC used for the study was toroidal re-entrant (TRCC. The experimental tests showed that BHO and BCO fuelled CRDI engine showed overall improved performance with 7 hole injector when engine was operated at optimized fuel IT of 10° before top dead centre (bTDC and IP of 900 bar. The smoke emission reduced by 20% to 26% and NOx reduced by 16% to 20% in diesel and biodiesel powered CRDI engine as compared to conventional CI mode besides replacing diesel by biodiesel fuel (BDF.

  3. ORF Sequence: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002695 gi|15830145 >gi|15830145|ref|NP_308918.1| putative transmembrane subunit...IFVPIGALQAGEALWHWSVIPLGLAVAILSTALPYSLEMIALTRLPTRTFGTLMSMEPALAAVSGMIFLGETLTPIQLLALGAIIAASMGSTLTVRKESKIKELDIN

  4. ORF Sequence: NC_004307 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_004307 gi|23464690 >gi|23464690|ref|NP_695293.1| hypothetical transmembrane pro...LVQLCAMGFIIGYVIRSNNVWMVFSLMAVMLVAAVQIVMSRARGIPKGLAGPIFLSLVITMLLMLALVTELIVRPHPWYAPQLVVPLTGMLLGNTVSALAVGLSRFYESME

  5. ORF Sequence: NC_005027 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_005027 gi|32471017 >gi|32471017|ref|NP_864010.1| hypothetical protein-transmemb...HALISRLRIWGRETLTEMPSWLVSMVVHLTLLLVLALIGRSTSKVGQIELLFRQSSESSSMELAEFTIAAAAPLESFERSMEEERIATTQLVSIDVIDAEAEMFSLVP

  6. ORF Sequence: NC_002942 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_002942 gi|52840424 >gi|52840424|ref|YP_094223.1| probable transmembrane protein...EYKRAQKQTFVMFFKGSLKGLVTTAPVTYRGVKIGEVKVIEITENKEHSKVLIPVYVQFFVERTYGFSQDPIHLLIDNGYVANITKPNLLTGVAEIELIKPTPAVKYKQTYYHSYPVFPTHNSAEKYTSME

  7. ORF Sequence: NC_005027 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_005027 gi|32476407 >gi|32476407|ref|NP_869401.1| hypothetical protein-transmemb...IYPDDRPGWIDQPIVNDGKDYSLVVTAGPSGSMEEADELIGVYARGAVQSYVDELVSEQEWATEPEMIPLDIDWIRDELVVRRYEGVVQVGDEQQFEKAILIRIEPEDKKVFETAIADMKLKERLAATGIVILGGFSLLVGGSIVLGGLASRQKQPTAAA

  8. Research on NC motion controller based on SOPC technology

    Science.gov (United States)

    Jiang, Tingbiao; Meng, Biao

    2006-11-01

    With the rapid development of the digitization and informationization, the application of numerical control technology in the manufacturing industry becomes more and more important. However, the conventional numerical control system usually has some shortcomings such as the poor in system openness, character of real-time, cutability and reconfiguration. In order to solve these problems, this paper investigates the development prospect and advantage of the application in numerical control area with system-on-a-Programmable-Chip (SOPC) technology, and puts forward to a research program approach to the NC controller based on SOPC technology. Utilizing the characteristic of SOPC technology, we integrate high density logic device FPGA, memory SRAM, and embedded processor ARM into a single programmable logic device. We also combine the 32-bit RISC processor with high computing capability of the complicated algorithm with the FPGA device with strong motivable reconfiguration logic control ability. With these steps, we can greatly resolve the defect described in above existing numerical control systems. For the concrete implementation method, we use FPGA chip embedded with ARM hard nuclear processor to construct the control core of the motion controller. We also design the peripheral circuit of the controller according to the requirements of actual control functions, transplant real-time operating system into ARM, design the driver of the peripheral assisted chip, develop the application program to control and configuration of FPGA, design IP core of logic algorithm for various NC motion control to configured it into FPGA. The whole control system uses the concept of modular and structured design to develop hardware and software system. Thus the NC motion controller with the advantage of easily tailoring, highly opening, reconfigurable, and expandable can be implemented.

  9. 78 FR 24071 - Safety Zone; Pasquotank River; Elizabeth City, NC

    Science.gov (United States)

    2013-04-24

    ... 1625-AA00 Safety Zone; Pasquotank River; Elizabeth City, NC AGENCY: Coast Guard, DHS. ACTION: Temporary... Pasquotank River in Elizabeth City, NC in support of the Fireworks display for the Potato Festival. This... Guard is establishing a safety zone on the navigable waters of Pasquotank River in Elizabeth City, NC...

  10. 78 FR 72009 - Establishment of Class E Airspace; Star, NC

    Science.gov (United States)

    2013-12-02

    ...-0440; Airspace Docket No. 13-ASO-10] Establishment of Class E Airspace; Star, NC AGENCY: Federal... at Star, NC, to accommodate a new Area Navigation (RNAV) Global Positioning System (GPS) Standard... Federal Register a notice of proposed rulemaking to establish Class E airspace at Star, NC (78 FR 54413...

  11. Batch vs continuous-feeding operational mode for the removal of pesticides from agricultural run-off by microalgae systems: A laboratory scale study

    Energy Technology Data Exchange (ETDEWEB)

    Matamoros, Víctor, E-mail: victor.matamoros@idaea.csic.es; Rodríguez, Yolanda

    2016-05-15

    Highlights: • The effect of microalgae on the removal of pesticides has been evaluated. • Continuous feeding operational mode is more efficient for removing pesticides. • Microalgae increased the removal of some pesticides. • Pesticide TPs confirmed that biodegradation was relevant. - Abstract: Microalgae-based water treatment technologies have been used in recent years to treat different water effluents, but their effectiveness for removing pesticides from agricultural run-off has not yet been addressed. This paper assesses the effect of microalgae in pesticide removal, as well as the influence of different operation strategies (continuous vs batch feeding). The following pesticides were studied: mecoprop, atrazine, simazine, diazinone, alachlor, chlorfenvinphos, lindane, malathion, pentachlorobenzene, chlorpyrifos, endosulfan and clofibric acid (tracer). 2 L batch reactors and 5 L continuous reactors were spiked to 10 μg L{sup −1} of each pesticide. Additionally, three different hydraulic retention times (HRTs) were assessed (2, 4 and 8 days) in the continuous feeding reactors. The batch-feeding experiments demonstrated that the presence of microalgae increased the efficiency of lindane, alachlor and chlorpyrifos by 50%. The continuous feeding reactors had higher removal efficiencies than the batch reactors for pentachlorobenzene, chlorpyrifos and lindane. Whilst longer HRTs increased the technology’s effectiveness, a low HRT of 2 days was capable of removing malathion, pentachlorobenzene, chlorpyrifos, and endosulfan by up to 70%. This study suggests that microalgae-based treatment technologies can be an effective alternative for removing pesticides from agricultural run-off.

  12. Design of Incremental Conductance Sliding Mode MPPT Control Applied by Integrated Photovoltaic and Proton Exchange Membrane Fuel Cell System under Various Operating Conditions for BLDC Motor

    Directory of Open Access Journals (Sweden)

    Jehun Hahm

    2015-01-01

    Full Text Available This paper proposes an integrated photovoltaic (PV and proton exchange membrane fuel cell (PEMFC system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing efficiency by means of maximum power point tracking (MPPT is particularly important. To manage such a hybrid system, control strategies need to be established to achieve the aim of the distributed system. Firstly, a Matlab/Simulink based model of the PV and PEMFC is developed and validated, as well as the incremental conductance sliding (ICS MPPT technique; then, different MPPT algorithms are employed to control the PV array under nonuniform temperature and insolation conditions, to study these algorithms effectiveness under various operating conditions. Conventional techniques are easy to implement but produce oscillations at MPP. Compared to these techniques, the proposed technique is more efficient; it produces less oscillation at MPP in the steady state and provides more precise tracking.

  13. Batch vs continuous-feeding operational mode for the removal of pesticides from agricultural run-off by microalgae systems: A laboratory scale study

    International Nuclear Information System (INIS)

    Matamoros, Víctor; Rodríguez, Yolanda

    2016-01-01

    Highlights: • The effect of microalgae on the removal of pesticides has been evaluated. • Continuous feeding operational mode is more efficient for removing pesticides. • Microalgae increased the removal of some pesticides. • Pesticide TPs confirmed that biodegradation was relevant. - Abstract: Microalgae-based water treatment technologies have been used in recent years to treat different water effluents, but their effectiveness for removing pesticides from agricultural run-off has not yet been addressed. This paper assesses the effect of microalgae in pesticide removal, as well as the influence of different operation strategies (continuous vs batch feeding). The following pesticides were studied: mecoprop, atrazine, simazine, diazinone, alachlor, chlorfenvinphos, lindane, malathion, pentachlorobenzene, chlorpyrifos, endosulfan and clofibric acid (tracer). 2 L batch reactors and 5 L continuous reactors were spiked to 10 μg L"−"1 of each pesticide. Additionally, three different hydraulic retention times (HRTs) were assessed (2, 4 and 8 days) in the continuous feeding reactors. The batch-feeding experiments demonstrated that the presence of microalgae increased the efficiency of lindane, alachlor and chlorpyrifos by 50%. The continuous feeding reactors had higher removal efficiencies than the batch reactors for pentachlorobenzene, chlorpyrifos and lindane. Whilst longer HRTs increased the technology’s effectiveness, a low HRT of 2 days was capable of removing malathion, pentachlorobenzene, chlorpyrifos, and endosulfan by up to 70%. This study suggests that microalgae-based treatment technologies can be an effective alternative for removing pesticides from agricultural run-off.

  14. A flexible control strategy of plug-in electric vehicles operating in seven modes for smoothing load power curves in smart grid

    International Nuclear Information System (INIS)

    Khemakhem, Siwar; Rekik, Mouna; Krichen, Lotfi

    2017-01-01

    Plug-in electric vehicles (PEVs) seem to be an interesting new electrical load for improving the reliability of smart grid. The purpose of this work is to investigate a supervision strategy based on regulated charging of PEVs in order to guarantee an optimized power management of the system and consequently a flatter power demand curve. The system mainly includes PEVs powered by a Lithium-ion battery ensuring the charging and discharging operations of these PEVs at home and a daily load power demanded by home appliances. The purpose of the considered strategy is to detect the connection status of each PEV and to establish the priority order between these PEVs with certain flexibility which results in managing the PEVs through seven operating modes. The response of the control algorithm enables to ensure the power flow exchange between the PEVs and the electrical grid, especially at rush hours, and to minimize load power variance aiming to achieve the smoothness for the power demand curve and to reduce the stress of the electrical grid. The simulation results are presented in order to illustrate the efficiency of this power control approach. - Highlights: • A flexible power management algorithm of Plug-in electric vehicle is proposed. • This control can be applied for any home equipped with two PEVs. • The response is to ensure the power flow exchange between PEVs and power grid. • The main contribution is to achieve the smoothness for the daily power demand curve.

  15. Dark current studies on a normal-conducting high-brightness very-high-frequency electron gun operating in continuous wave mode

    Directory of Open Access Journals (Sweden)

    R. Huang

    2015-01-01

    Full Text Available We report on measurements and analysis of a field-emitted electron current in the very-high-frequency (VHF gun, a room temperature rf gun operating at high field and continuous wave (CW mode at the Lawrence Berkeley National Laboratory (LBNL. The VHF gun is the core of the Advanced Photo-injector Experiment (APEX at LBNL, geared toward the development of an injector for driving the next generation of high average power x-ray free electron lasers. High accelerating fields at the cathode are necessary for the high-brightness performance of an electron gun. When coupled with CW operation, such fields can generate a significant amount of field-emitted electrons that can be transported downstream the accelerator forming the so-called “dark current.” Elevated levels of a dark current can cause radiation damage, increase the heat load in the downstream cryogenic systems, and ultimately limit the overall performance and reliability of the facility. We performed systematic measurements that allowed us to characterize the field emission from the VHF gun, determine the location of the main emitters, and define an effective strategy to reduce and control the level of dark current at APEX. Furthermore, the energy spectra of isolated sources have been measured. A simple model for energy data analysis was developed that allows one to extract information on the emitter from a single energy distribution measurement.

  16. NNT reverse mode of operation mediates glucose control of mitochondrial NADPH and glutathione redox state in mouse pancreatic β-cells

    Directory of Open Access Journals (Sweden)

    Laila R.B. Santos

    2017-06-01

    Full Text Available Objective: The glucose stimulation of insulin secretion (GSIS by pancreatic β-cells critically depends on increased production of metabolic coupling factors, including NADPH. Nicotinamide nucleotide transhydrogenase (NNT typically produces NADPH at the expense of NADH and ΔpH in energized mitochondria. Its spontaneous inactivation in C57BL/6J mice was previously shown to alter ATP production, Ca2+ influx, and GSIS, thereby leading to glucose intolerance. Here, we tested the role of NNT in the glucose regulation of mitochondrial NADPH and glutathione redox state and reinvestigated its role in GSIS coupling events in mouse pancreatic islets. Methods: Islets were isolated from female C57BL/6J mice (J-islets, which lack functional NNT, and genetically close C57BL/6N mice (N-islets. Wild-type mouse NNT was expressed in J-islets by adenoviral infection. Mitochondrial and cytosolic glutathione oxidation was measured with glutaredoxin 1-fused roGFP2 probes targeted or not to the mitochondrial matrix. NADPH and NADH redox state was measured biochemically. Insulin secretion and upstream coupling events were measured under dynamic or static conditions by standard procedures. Results: NNT is largely responsible for the acute glucose-induced rise in islet NADPH/NADP+ ratio and decrease in mitochondrial glutathione oxidation, with a small impact on cytosolic glutathione. However, contrary to current views on NNT in β-cells, these effects resulted from a glucose-dependent reduction in NADPH consumption by NNT reverse mode of operation, rather than from a stimulation of its forward mode of operation. Accordingly, the lack of NNT in J-islets decreased their sensitivity to exogenous H2O2 at non-stimulating glucose. Surprisingly, the lack of NNT did not alter the glucose-stimulation of Ca2+ influx and upstream mitochondrial events, but it markedly reduced both phases of GSIS by altering Ca2+-induced exocytosis and its metabolic amplification. Conclusion: These

  17. Virtual NC machine model with integrated knowledge data

    International Nuclear Information System (INIS)

    Sidorenko, Sofija; Dukovski, Vladimir

    2002-01-01

    The concept of virtual NC machining was established for providing a virtual product that could be compared with an appropriate designed product, in order to make NC program correctness evaluation, without real experiments. This concept is applied in the intelligent CAD/CAM system named VIRTUAL MANUFACTURE. This paper presents the first intelligent module that enables creation of the virtual models of existed NC machines and virtual creation of new ones, applying modular composition. Creation of a virtual NC machine is carried out via automatic knowledge data saving (features of the created NC machine). (Author)

  18. NC10 bacteria in marine oxygen minimum zones

    DEFF Research Database (Denmark)

    Padilla, Cory C; Bristow, Laura A; Sarode, Neha

    2016-01-01

    Bacteria of the NC10 phylum link anaerobic methane oxidation to nitrite denitrification through a unique O2-producing intra-aerobic methanotrophy pathway. A niche for NC10 in the pelagic ocean has not been confirmed. We show that NC10 bacteria are present and transcriptionally active in oceanic....... rRNA and mRNA transcripts assignable to NC10 peaked within the OMZ and included genes of the putative nitrite-dependent intra-aerobic pathway, with high representation of transcripts containing the unique motif structure of the nitric oxide (NO) reductase of NC10 bacteria, hypothesized...

  19. Microtearing modes

    International Nuclear Information System (INIS)

    Garbet, X.; Mourgues, F.; Samain, A.; Zou, X.

    1990-01-01

    A serious degradation of confinement with additional heating is commonly observed on most tokamaks. The microtearing modes could provide an explanation for this experimental fact. They are driven linearly unstable by diamagnetism in collisional regimes, but it may be shown that the collisions in non linear regimes provide a small diffusion coefficient which can be only significant at the plasme edge. In the bulk of the plasma, the microtearing turbulence could play a basic role if it is unstable in the collisionless regime. While it is linearly stable without collisions, it could be driven unstable in realistic regimes by the radial diffusion it induces. To study this effect, we have used a model where the non linear action of the modes on a given helicity component is represented by a diffusion operator. They are found unstable for reasonable β p =2μ o nT/B 2 p , with a special radial profile of the potential vector A. The problem arises the validity of this model where non linearities in the trajectories behaviour are replaced by the diffusion which broadens resonances. To test this procedure, we calculate the actual electron distribution function when it is determined by the ergodicity of the field lines. We compute the correlations of the distribution function with the magnetic perturbation and compare them with the analytical expressions derived from the resonance broadening model. (author) 3 refs., 2 figs

  20. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.