WorldWideScience

Sample records for undesirable operating modes

  1. Study on Operator Actions during the Occurrences of Undesirable Events in PUSPATI TRIGA Reactor

    International Nuclear Information System (INIS)

    Tom, P.P.; Nurul Husna Zainal Abidin; Lanyau, T.A.; Zaredah Hashim

    2016-01-01

    Due to the recent Fukushima accident, the potential risks at one and only nuclear research reactor in the country, which is the PUSPATI TRIGA Reactor (RTP), has increasingly gain concerns and an attempt on the development of Level 1 Probabilistic Safety Assessment (PSA) for this reactor has been commenced. The preliminary scope of the PSA is to analyse the risk of core degradation during normal daily operation due to the random component failure and human error. SPAR-H and THERP method is used for quantifying human error probability (HEP). However, the scopes of this study only cover the qualitative parts that use interview/questionnaire method. The objectives of the questionnaire are to identify the main action for RTP operators when any undesired incident occurs during full power operation that might be caused by random component failures. From the questionnaires that have been conducted, the respondents consisted of 4 licensed operators and 9 trainee operators. All licensed operators have experience of operating reactor for more than 15 years while the trainee operator have been operate the reactor with experience of less than 10 years. Generally, in the event of an abnormal condition involving the reactor, an operator whether a licensed operator or the trainee does not have to ask permission in advance from the top individuals to carry out scram. This is to prevent the situation becoming increasingly severe if the reactor is still operating. With complete training and knowledge derived from the management, an operator can act efficiently in any emergency case. (author)

  2. Operation condition for continuous anti-solvent crystallization of CBZ-SAC cocrystal considering deposition risk of undesired crystals

    Science.gov (United States)

    Nishimaru, Momoko; Nakasa, Miku; Kudo, Shoji; Takiyama, Hiroshi

    2017-07-01

    Crystallization operation of cocrystal production has deposition risk of undesired crystals. Simultaneously, continuous manufacturing processes are focused on. In this study, conditions for continuous cocrystallization considering risk reduction of undesired crystals deposition were investigated on the view point of thermodynamics and kinetics. The anti-solvent cocrystallization was carried out in four-component system of carbamazepine, saccharin, methanol and water. From the preliminary batch experiment, the relationships among undesired crystal deposition, solution composition decided by mixing ratio of solutions, and residence time for the crystals were considered, and then the conditions of continuous experiment were decided. Under these conditions, the continuous experiment was carried out. The XRD patterns of obtained crystals in the continuous experiment showed that desired cocrystals were obtained without undesired crystals. This experimental result was evaluated by using multi-component phase diagrams from the view point of the operation point's movement. From the evaluation, it was found that there is a certain operation condition which the operation point is fixed with time in the specific domain without the deposition risk of undesired single component crystals. It means the possibility of continuous production of cocrystals without deposition risk of undesired crystals was confirmed by using multi-component phase diagrams.

  3. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

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

    2011-01-01

    An enduring characteristic of extant literature on foreign operation modes is its discrete choice approach, where companies are assumed to choose one among a small number of distinctive alternatives. In this paper we use detailed information about the operations of six Norwegian companies in three...... 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...... 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...

  4. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

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

    2011-01-01

    An enduring characteristic of extant literature on foreign operation modes is its discrete choice approach, where companies are assumed to choose one among a small number of distinctive alternatives. In this paper, detailed information about the operations of six Norwegian companies in three key...... 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...... 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...

  5. 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)

  6. Language Differences and Operation Mode

    DEFF Research Database (Denmark)

    Dasi, Angels; Pedersen, Torben

    2013-01-01

    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......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......, and Sweden that have undertaken a business operation in a foreign country....

  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. 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.

  9. 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

  10. 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)

  11. A CMOS current-mode operational amplifier

    DEFF Research Database (Denmark)

    Kaulberg, Thomas

    1993-01-01

    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 balanc...

  12. 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)

  13. 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

  14. 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

  15. Operational modes of french 900 MW nuclear power plant

    International Nuclear Information System (INIS)

    Shen Rugang

    1991-01-01

    The operational safety criteria of the PWR French 900 MW nuclear power plant and their operational modes: Mode A and Mode G is briefly introduced. The principle of the basic control, the operational performance, the advantages and the shortcomings of two modes are compared

  16. Operation modes of the molecular motor kinesin

    Science.gov (United States)

    Liepelt, S.; Lipowsky, R.

    2009-01-01

    The velocity and the adenosine triphosphate (ATP) hydrolysis rate of the molecular motor kinesin are studied using a general network representation for the motor, which incorporates both the energetics of ATP hydrolysis and the experimentally observed separation of time scales between chemical and mechanical transitions. Both the motor velocity and its hydrolysis rate can be expressed as superpositions of excess fluxes for the directed cycles (or dicycles) of the network. The sign of these dicycle excess fluxes depends only on two thermodynamic control parameters as provided by the load force F and the chemical energy Δμ released during the hydrolysis of a single ATP molecule. In contrast, both the motor velocity and its hydrolysis rate depend, in general, on the load force F as well as on the three concentrations of ATP, adenosine diphosphate (ADP), and inorganic phosphate (P), separately. Thus, in order to represent the different operation modes of the motor in the (F,Δμ) plane, one has to specify two concentrations such as the product concentrations [ADP] and [P]. As a result, we find four different operation modes corresponding to the four possible combinations of ATP hydrolysis or synthesis with forward or backward mechanical steps. Our operation diagram implies in particular that backward steps are coupled to ATP hydrolysis for sufficiently large ATP concentrations, but to ATP synthesis for sufficiently large ADP and/or P concentrations.

  17. 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

  18. 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

  19. Extracting Operating Modes from Building Electrical Load Data: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Frank, S.; Polese, L. G.; Rader, E.; Sheppy, M.; Smith, J.

    2012-01-01

    Empirical techniques for characterizing electrical energy use now play a key role in reducing electricity consumption, particularly miscellaneous electrical loads, in buildings. Identifying device operating modes (mode extraction) creates a better understanding of both device and system behaviors. Using clustering to extract operating modes from electrical load data can provide valuable insights into device behavior and identify opportunities for energy savings. We present a fast and effective heuristic clustering method to identify and extract operating modes in electrical load data.

  20. 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...

  1. 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

  2. France operates in the grey mode [load following

    International Nuclear Information System (INIS)

    Bacher, P.

    1985-01-01

    Load following is becoming an important feature of PWR operation in France. To achieve maximum operating flexibility a new control system, Mode G, is being introduced based on the use of low negative reactivity, or grey, control rods. (author)

  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

    Floating, Production, Storage and Offloading (FPSO) is a floating facility used in primary petroleum processing. In Brazil, most FPSOs have been installed in Campos Basin and new facilities may be implemented in the pre-salt area are projected to boost the Brazilian oil production. Crude oil...... composition has a significant influence on the operational mode of the FPSO. In this study, three operational modes of a FPSO are assessed: the first mode is used when the crude oil has the maximum water and CO2 contents, the second mode is implemented for a composition of 50% basic sediment and water (BSW......) in the crude oil, and the third mode is operated when the crude oil has the maximum oil and gas fractions. The FPSO facility configuration changes with the operational mode, and it is possible to have gas export, gas injection, and CO2 injection, in order to achieve the functional conditions established...

  4. 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.

  5. Filtering Undesirable Flows in Networks

    NARCIS (Netherlands)

    Polevoy, G.; Trajanovski, S.; Grosso, P.; de Laat, C.; Gao, X.; Du, H.; Han, M.

    2017-01-01

    We study the problem of fully mitigating the effects of denial of service by filtering the minimum necessary set of the undesirable flows. First, we model this problem and then we concentrate on a subproblem where every good flow has a bottleneck. We prove that unless P=NP, this subproblem is

  6. 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.

  7. Modeling Operating Modes during Plant Life Cycle

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lind, Morten

    2012-01-01

    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...... regions within the plant operating window, including transitions between operating regions. Subsequently qualitative functional models may be developed when the means for achieving the desired functionality are sufficiently specified during the design process. Quantitative mathematical models of plant...... physics can be used for detailed design and optimization. However the qualitative functional models already provide a systematic framework based on the notion of means-end abstraction hierarchies. Thereby functional modeling provides a scientific basis for managing complexity. A functional modelling...

  8. Representing Operational Modes for Situation Awareness

    DEFF Research Database (Denmark)

    Kirchhübel, Denis; Lind, Morten; Ravn, Ole

    2017-01-01

    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...... 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...

  9. 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...

  10. Proving Chaotic Behavior of CBC Mode of Operation

    Science.gov (United States)

    Abidi, Abdessalem; Wang, Qianxue; Bouallegue, Belgacem; Machhout, Mohsen; Guyeux, Christophe

    2016-06-01

    The cipher block chaining (CBC) mode of operation was invented by IBM (International Business Machine) in 1976. It presents a very popular way of encrypting that is used in various applications. In this paper, we have mathematically proven that, under some conditions, the CBC mode of operation can admit a chaotic behavior according to Devaney. Some cases will be properly studied in order to provide evidence for this idea.

  11. 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.

  12. Thermoneutral Operation of Solid Oxide Electrolysis Cells in Potentiostatic Mode

    DEFF Research Database (Denmark)

    Chen, Ming; Sun, Xiufu; Chatzichristodoulou, Christodoulos

    2017-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for energy storage and synthetic fuel production. In recent years extensive efforts have been devoted to improving performance and durability of SOEC cells and stacks. Due to historical reasons...... and the convenience of doing constant current tests, (almost) all the reported SOEC tests have been galvanostatic. In this work, we report test results on two types of SOEC cells operated for electrolysis of steam in potentiostatic mode at 1.29 V. Both cells are Ni/YSZ fuel electrode supported type with different...... cause of the degradation. Operation strategies were further proposed for electrolysis operation in potentiostatic mode....

  13. Operational experience with the LHC waveguide mode reflectometer

    CERN Document Server

    Borowiec, P; Kroyer, T; Sulek, Z; Williams, L

    2006-01-01

    The LHC microwave mode reflectometer (assembly version) reached operational status by the autumn of 2005. It is now routinely used in the LHC tunnel and on the surface to take data on the beam screens of the individual LHC magnets and also groups of magnets with lengths up to 100 meters. The reflectometer operates in the frequency range from about 4 GHz to 10 GHz and employs mode selective launchers. This paper discusses the operational aspects of the system as well as methods for clutter (fake reflection) elimination and procedures for cross-checks in case of a suspected obstacle or other fault

  14. 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

  15. Dirac operator zero-modes on a torus

    International Nuclear Information System (INIS)

    Tenjinbayashi, Yasushi; Igarashi, Hiroshi; Fujiwara, Takanori

    2007-01-01

    We study Dirac operator zero-modes on a torus for gauge background with uniform field strengths. Under the basic translations of the torus coordinates the wave functions are subject to twisted periodic conditions. In suitable torus coordinates the zero-mode wave functions can be related to holomorphic functions of the complex torus coordinates. Half of the twisted boundary conditions for the holomorphic part of the zero-mode wave function can be made periodic or anti-periodic. The remaining half is until coordinate dependent but diagonal. We completely solve the twisted boundary conditions and construct the zero-mode wave functions. The chirality and the degeneracy of the zero-modes are uniquely determined by the gauge background and are consistent with the index theorem

  16. Analysis of zero modes for Dirac operators with magnetic links

    DEFF Research Database (Denmark)

    Portmann, Fabian Daniel; Sok, Jérémy Vithya; Solovej, Jan Philip

    2017-01-01

    In this paper we provide a means to approximate Dirac operators with magnetic fields supported on links in S3 (and R3) by Dirac operators with smooth magnetic fields. We then proceed to prove that under certain assumptions, the spectral flow of paths along these operators is the same in both the ...... obtain criteria on the magnetic link for the non-existence of zero modes....

  17. Hospital bed ventilation: impact of operation mode on exposure

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor; Barova, Mariya

    2014-01-01

    and droplet nuclei of less than 3 μm aerodynamic diameter. Two modes of operation of the bed incorporated ventilation unit were tested: releasing the cleaned air upwards (pull mode) or supplying it sideways over the lying patient (“push and pull” mode). The strategy to exhaust pollutants close o release...... proved to be efficient. The bed incorporated ventilation unit was effective in capturing the air exhaled by the sick lying patient and performed significantly better than the overhead ventilation at 12 ACH. The exposure for the doctor and the second patient was further reduced when the bed incorporated...

  18. 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

    2018-03-26

    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

  19. 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...

  20. Experimental characterization of collapse-mode CMUT operation.

    Science.gov (United States)

    Oralkan, Omer; Bayram, Baris; Yaralioglu, Goksen G; Ergun, A Sanli; Kupnik, Mario; Yeh, David T; Wygant, Ira O; Khuri-Yakub, Butrus T

    2006-08-01

    This paper reports on the experimental characterization of collapse-mode operation of capacitive micromachined ultrasonic transducers (CMUTs). CMUTs are conventionally operated by applying a direct current (DC) bias voltage less than the collapse voltage of the membrane, so that the membrane is deflected toward the bottom electrode. In the conventional regime, there is no contact between the membrane and the substrate; the maximum alternating current (AC) displacement occurs at the center of the membrane. In collapse-mode operation, the DC bias voltage is first increased beyond the collapse voltage, then reduced without releasing the collapsed membrane. In collapse-mode operation, the center of the membrane is always in contact with the substrate. In the case of a circular membrane, the maximum AC displacement occurs along the ring formed between the center and the edge of the membrane. The experimental characterization presented in this paper includes impedance measurements in air, pulse-echo experiments in immersion, and one-way optical displacement measurements in immersion for both conventional and collapse-mode operations. A 205-microm x 205-microm 2-D CMUT array element composed of circular silicon nitride membranes is used in the experiments. In pulse-echo experiments, a custom integrated circuit (IC) comprising a pulse driver, a transmit/receive switch, a wideband low-noise preamplifier, and a line driver is used. By reducing the parasitic capacitance, the use of a custom IC enables pulse-echo measurements at high frequencies with a very small transducer. By comparing frequency response and efficiency of the transducer in conventional and collapse regimes, experimental results show that a collapsed membrane can be used to generate and detect ultrasound more efficiently than a membrane operated in the conventional mode. Furthermore, the center frequency of the collapsed membrane can be changed by varying the applied DC voltage. In this study, the center

  1. 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.

  2. 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.

  3. 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.

  4. Pulse mode operation of Love wave devices for biosensing applications.

    Science.gov (United States)

    Newton, M I; McHale, G; Martin, F; Gizeli, E; Melzak, K A

    2001-12-01

    In this work we present a novel pulse mode Love wave biosensor that monitors both changes in amplitude and phase. A series of concentrations of 3350 molecular weight poly(ethylene glycol) (PEG) solutions are used as a calibration sequence for the pulse mode system using a network analyzer and high frequency oscilloscope. The operation of the pulse mode system is then compared to the continuous wave network analyzer by showing a sequence of deposition and removal of a model mass layer of palmitoyl-oleoyl-sn-glycerophosphocholine (POPC) vesicles. This experimental apparatus has the potential for making many hundreds of measurements a minute and so allowing the dynamics of fast interactions to be observed.

  5. 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)

  6. 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.

  7. The Passive Operating Mode of the Linear Optical Gesture Sensor

    Directory of Open Access Journals (Sweden)

    CZUSZYNSKI, K.

    2018-02-01

    Full Text Available The study evaluates the influence of natural light conditions on the effectiveness of the linear optical gesture sensor, working in the presence of ambient light only (passive mode. The orientations of the device in reference to the light source were modified in order to verify the sensitivity of the sensor. A criterion for the differentiation between two states - "possible gesture" and "no gesture" - was proposed. Additionally, different light conditions and possible features were investigated, relevant for the decision of switching between the passive and active modes of the device. The criterion was evaluated based on the specificity and sensitivity analysis of the binary ambient light condition classifier. The elaborated classifier predicts ambient light conditions with the accuracy of 85.15%. Understanding the light conditions, the hand pose can be detected. The achieved accuracy of the hand poses classifier trained on the data obtained in the passive mode in favorable light conditions was 98.76%. It was also shown that the passive operating mode of the linear gesture sensor reduces the total energy consumption by 93.34%, resulting in 0.132 mA. It was concluded that optical linear sensor could be efficiently used in various lighting conditions.

  8. 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

  9. 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.

  10. Security-constrained unit commitment with flexible operating modes

    Science.gov (United States)

    Lu, Bo

    The electricity industry throughout the world, which has long been dominated by vertically integrated utilities, is facing enormous challenges. To enhance the competition in electricity industry, vertically integrated utilities are evolving into a distributed and competitive industry in which market forces drive the price of electricity and possibly reduce the net cost of supplying electrical loads through increased competition. To excel in the competition, generation companies (GENCOs) will acquire additional generating units with flexible operating capability which allows a timely response to the continuous changes in power system conditions. This dissertation considers the short-term scheduling of generating units with flexible modes of operation in security-constrained unit commitment (SCUC). Among the units considered in this study are combined cycle units, fuel switching/blending units, photovoltaic/battery system, pumped-storage units, and cascaded hydro units. The proposed security-constrained unit commitment solution will include a detailed model of transmission system which could impact the short-term scheduling of units with flexible operation modes.

  11. 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.

  12. Operational limit conditions of the spur gears in lubricated modes

    Science.gov (United States)

    Benilha, S.; Belarifi, F.

    2018-01-01

    The calculation of the gear teeth resistance, shows the using of a certain number of coefficients determined experimentally and which are accepted by the various international standards. However, this kind of calculation determines the gears by excess material and does not support the tribological parameters of operation. We propose in this work the support of these parameters, to determine the limit operation conditions of the spur gears, using the equivalent geometry. This is represented by two cylinders, which geometrically models of the contact between two teeth of a gear and whose lubrication is generally in mixed lubrication mode. The concept of Mc cool is used to determine the distribution of the load and the friction force, which are distributed in liquid (elastohydrodynamic) and solid domains and interact with each other. The phenomenon of interaction between the two domains is used, to predict the tribological limit conditions of operation. The proposed model is based on the resolution of elastohydrodynamic equations for the determination of load and friction as well as the deduction of mixed friction by tracing the Stribeck curve. This is calculated by the model of the decomposition of the patterns profile of rough surfaces in contacts. The results of non-dimensional calculations allow us to deduce the boundary conditions and can be adapted for any type of gear pair defined according to pre-established operating conditions.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Operation of the LEP CW Klystrons in Pulsed Mode

    CERN Document Server

    Frischholz, Hans

    2003-01-01

    For possible future accelerator projects, as, e. g., the Super-Conducting Proton Linac, SPL, at CERN, it would be desirable to reuse as much of the LEP/RF equipment as possible. In the SPL, as in other proposed proton linacs, pulsed operation is required with RF pulse-lengths varying between 1 and 3 ms and a pulse repetition rate of 50 Hz. The LEP klystrons are equipped with a modulation anode by means of which their beam current and hence the output power can be controlled. In LEP the klystron output power had to be varied very slowly when the energy was ramped. In order to keep a high efficiency also in pulsed mode the rise- and fall-time of the beam pulse in the klystron should be considerably less than 100µs. This goal was achieved by modifying the tetrode modulator, the HV line between modulator and klystron, and the filter network of the HV power supply. SPICE simulations were performed to evaluate the optimum values of capacitors and inductors in the HV filtering network of the LEP 100kV, 40A power co...

  18. 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.

  19. 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.

  20. 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.

  1. Loosen Couple Workflow Mode of Lean Operator Improvement Based on Positive Feedback

    Directory of Open Access Journals (Sweden)

    Yao Li

    2013-04-01

    Full Text Available In order to promote the core competitive power for telecom operating enterprises to face market fine operation, this article compares the ECTA mode (Extension Case Transmission Mode and the LCA mode (Loosen Couple Mode, both of which are promoted by WfMC. By comparing these two modes, the suitable situations for these two modes are determined. We also carry out empirical analysis based on the customization mode of mobile phones between China telecom and mobile phone manufacturers and to expound the ascension effect of mechanism based on the agile telecom loose coupling workflow with positive feedback to the telecom enterprises. Finally, on the basis of positive feedback system, the task complexity and information transparency of LCA mode are improved, so that the semantics of public flow mode is kept unchanged and the sub workflow is optimized when modifying the sub workflow.

  2. 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

  3. 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

  4. 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

  5. Undesirable effects after treatment with dermal fillers.

    Science.gov (United States)

    Rodrigues-Barata, Ana Rita; Camacho-Martínez, Francisco M

    2013-04-01

    Soft tissue augmentation is one of the most frequent techniques in cosmetic dermatology. Nowadays, there are a high number of available materials. Nonanimal hyaluronic acid (HA) is one of most useful fillers for lip augmentation and for treating nasolabial folds, marionette lines, and the dynamic wrinkles of the upper face. To evaluate the type and management of undesirable effects of nonanimal reticulated or stabilized HA observed in our cosmetic unit in the past 3 years. The consecutive patients using HA attending to our clinic in the past 3 years were divided into 3 categories, according to the time of presentation of the adverse reactions: immediate, early, and late-onset complications. All patients were treated. Twenty-three patients presented to our clinic complaining of complications after soft tissue augmentation with HA. Ten patients presented immediate-onset complications, 8 showed early-onset complications, and 5 cases complaint of late-onset complications. Treatment of the first group consisted of hyaluronidase injection, massage, and topical antibiotics. Early- and late-onset complications were treated with intralesional triamcinolone acetonide. All patients improved, with the exception of a woman with recurrent granulomas. Generally, undesirable effects of HA (immediate, early, or late onset) are not frequent, and when present, they improve if treated properly. Physicians need to be aware of these possible adverse events in order to establish proper treatment and prevent scarring or other sequelae.

  6. The undesirable effects of neuromuscular blocking drugs

    DEFF Research Database (Denmark)

    Claudius, C; Garvey, L H; Viby-Mogensen, J

    2009-01-01

    Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

  7. Criterial approach to finding the current operation modes of high reliability thermoelectric devices

    Directory of Open Access Journals (Sweden)

    Zaikov V. P.

    2017-04-01

    Full Text Available The authors consider possibilities of the criterial approach to determining the current operating mode of a single-stage thermoelectric cooling unit (TCU, when used reliability failure rate as a basic parameter. The relations were obtained for determining the current operating mode of a TCU with a given geometry of the branches for different operating conditions, taking into account a variety of restrictive requirements. The paper presents a comparative analysis of current conditions close to the maximum energy efficiency and minimum modes failure rate, which allows choosing compromise options.

  8. 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

  9. 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.

  10. 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....... The random capacity of the channels are evaluated in terms of percentiles. For an SNR of 10 dB, median capacities in free space of about 4.4–4.7 bit/s/Hz for the low band and about 3.3– 3.8 bit/s/Hz for the high band were found. The mean decrease in capacity due to the user was found to be up to about 2...

  11. 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.

  12. 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

  13. 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.

  14. 47 CFR 73.840 - Operating power and mode tolerances.

    Science.gov (United States)

    2010-10-01

    ... tolerances. The transmitter power output (TPO) of an LPFM station must be determined by the procedures set forth in § 73.267 of this part. The operating TPO of an LPFM station with an authorized TPO of more than ten watts must be maintained as near as practicable to its authorized TPO and may not be less than 90...

  15. 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.

  16. 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.

  17. The mode of operation of CANDU power reactor in thorium self-sufficient fuel cycle

    Directory of Open Access Journals (Sweden)

    Bergelson Boris R.

    2008-01-01

    Full Text Available This paper presents the results of calculations for CANDU reactor operation in the thorium fuel cycle. The calculations were performed to estimate feasibility of operation of a heavy-water thermal neutron power reactor in the self-sufficient thorium cycle. The parameters of the active core and the scheme of fuel reloading were considered to be the same as for the standard operation in the uranium cycle. Two modes of operation are discussed in the paper: the mode of preliminary accumulation of 233U and the mode of operation in the self-sufficient cycle. For calculations for the mode of accumulation of 233U, it was assumed that plutonium was used as the additional fissile material to provide neutrons for 233U production. Plutonium was placed in fuel channels, while 232Th was located in target channels. The maximum content of 233U in the target channels was about 13 kg/t of ThO2. This was achieved by six year irradiation. The start of reactor operation in the self-sufficient mode requires content of 233U not less than 12 kg/t. For the mode of operation in the self-sufficient cycle, it was assumed that all the channels were loaded with the identical fuel assemblies containing ThO2 and a certain amount of 233U. It was shown that the non-uniform distribution of 233U in a fuel assembly is preferable.

  18. All-fiber passively mode-locked thulium-doped fiber ring oscillator operated at solitary and noiselike modes.

    Science.gov (United States)

    Wang, Q; Chen, T; Zhang, B; Heberle, A P; Chen, K P

    2011-10-01

    This Letter presents an all-fiber mode-locked thulium-doped fiber ring oscillator based on nonlinear polarization evolution (NPE). Pumped by an erbium-doped fiber amplified spontaneous emission source, the construction of the laser cavity consisting of only fiber optic components can operate under two different regimes of solitary and noiselike (NL) pulses. Autocorrelation measurements are performed to extract features of these two regimes. © 2011 Optical Society of America

  19. Analysis of space payload operation modes based on divide-and-conquer clustering

    Directory of Open Access Journals (Sweden)

    Si Feng

    2016-01-01

    Full Text Available With the development of space electronic technology, the space payload operation modes are more and more complex, and manual interpretation is prone to errors for much workload. Generally the space payload’s operation modes are reflected by its telemetry data. By analysing the characteristics of the payload telemetry data, it is proposed an automatic analysis method of payload operation modes based on divide–and–conquer clustering. The clustering method combines division and incremental clustering. The principle of the method is introduced and the method is validated using the actual payload telemetry data. Furthermore the improved method is proposed to the problems encountered. Experimental results show that divide–and–conquer clustering method has the feature of calculation simple and classification accurate, when applied to the classification of payload operation modes. Furthermore this method can be applied to the other areas of payload data processing by extending the method.

  20. NERVA-Derived Nuclear Thermal Propulsion Dual Mode Operation

    Science.gov (United States)

    Zweig, Herbert R.; Hundal, Rolv

    1994-07-01

    Generation of electrical power using the nuclear heat source of a NERVA-derived nuclear thermal rocket engine is presented. A 111,200 N thrust engine defined in a study for NASA-LeRC in FY92 is the reference engine for a three-engine vehicle for which a 50 kWe capacity is required. Processes are described for energy extraction from the reactor and for converting the energy to electricity. The tie tubes which support the reactor fuel elements are the source of thermal energy. The study focuses on process systems using Stirling cycle energy conversion operating at 980 K and an alternate potassium-Rankine system operating at 1,140 K. Considerations are given of the effect of the power production on turbopump operation, ZrH moderator dissociation, creep strain in the tie tubes, hydrogen permeation through the containment materials, requirements for a backup battery system, and the effects of potential design changes on reactor size and criticality. Nuclear considerations include changing tie tube materials to TZM, changing the moderator to low vapor-pressure yttrium hydride, and changing the fuel form from graphite matrix to a carbon-carbide composite.

  1. 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

  2. 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.

  3. Two methods for estimating aeroelastic damping of operational wind turbine modes from experiments

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig; Thomsen, Kenneth; Fuglsang, Peter

    2006-01-01

    The theory and results of two experimental methods for estimating the modal damping of a wind turbine during operation are presented. Estimations of the aeroelastic damping of the operational turbine modes (including the effects of the aerodynamic forces) give a quantitative view of the stability...... the deterministic excitation, and the modal frequencies and damping of the first tower and first edgewise whirling modes are extracted. Copyright © 2006 John Wiley & Sons, Ltd....

  4. A dynamical systems approach to the discrimination of the modes of operation of cryptographic systems

    OpenAIRE

    Machicao, Jeaneth; Baetens, Jan M.; Marco, Anderson G.; De Baets, Bernard; Bruno, Odemir M.

    2015-01-01

    Evidence of signatures associated with cryptographic modes of operation is established. Motivated by some analogies between cryptographic and dynamical systems, in particular with chaos theory, we propose an algorithm based on Lyapunov exponents of discrete dynamical systems to estimate the divergence among ciphertexts as the encryption algorithm is applied iteratively. The results allow to distinguish among six modes of operation, namely ECB, CBC, OFB, CFB, CTR and PCBC using DES, IDEA, TEA ...

  5. Calculation of the thermal mode in semiconductor devices in conditions of their operation in semiconductor apparatuses

    OpenAIRE

    Сосков, Анатолій Георгійович; Глєбова, Марина Леонідівна; Сабалаєва, Наталія Олегівна; Форкун, Яна Борисівна

    2014-01-01

    The study of the temperature field of power semiconductor devices, operating in semiconductor apparatuses, either non-contact or hybrid was carried out in the paper.It was also shown that the main mode of the current load of power semiconductor devices, operating in semiconductor apparatuses is a pulse mode.Analytical method for calculating the values of the temperature rise in the structure of power semiconductor devices when subjected to a current pulse of arbitrary shape based on a model t...

  6. 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

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Biebersdorf, A [Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universitaet, Amalienstrasse 54, D-80799 Munich (Germany); Lingk, C [Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universitaet, Amalienstrasse 54, D-80799 Munich (Germany); De Giorgi, M [Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universitaet, Amalienstrasse 54, D-80799 Munich (Germany); Feldmann, J [Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universitaet, Amalienstrasse 54, D-80799 Munich (Germany); Sacher, J [Sacher Lasertechnik GmbH, Hannah Arendt Strasse 3-7, D-35037 Marburg (Germany); Arzberger, M [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany); Ulbrich, C [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany); Boehm, G [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany); Amann, M-C [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany); Abstreiter, G [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany)

    2003-08-21

    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.

  9. 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.

  10. Multistage depressed collector for dual mode operation. [for microwave transmitting tubes

    Science.gov (United States)

    Kosmahl, H. C. (Inventor)

    1981-01-01

    A depressed collector which captures the spent electrons of a microwave transmitting tube at high efficiency in both high and low power modes of operation is described. The collector comprises entrance and end electrodes, the end electrode having a spike extending toward entrance electrode. Intermediate electrodes and the entrance electrode each have a central aperture and, together, these electrodes capture most high power mode spent electrons. The apertures of the electrodes increase in size in a downstream direction. To capture low power mode spent electrons a low power mode electrode is positioned between the last intermediate electrode and the end electrode. This electrode has a central aperture preferably smaller but no larger than that of the last intermediate electrode. An auxiliary low power mode electrode may be added having a central aperture larger than that of the low power mode electrode. All of the electrodes are at voltages provided by a voltage divider connected between a potential.

  11. 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.

  12. 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)

  13. Diverse mode of operation of an all-normal-dispersion mode-locked fiber laser employing two nonlinear loop mirrors.

    Science.gov (United States)

    Chowdhury, Sourav Das; Pal, Atasi; Chatterjee, Sayan; Sen, Ranjan; Pal, Mrinmay

    2018-02-10

    In this paper, we propose an all-normal-dispersion ytterbium-fiber laser with a novel ring cavity architecture having two nonlinear amplifying loop mirrors (NALM) as saturable absorbers, capable of delivering distinctly different pulses with adjustable features. By optimizing the loop lengths of the individual NALMs, the cavity can be operated to deliver Q-switched mode-locked (Q-ML) pulse bunches with adjustable repetition rates, mode-locked pulses in dissipative soliton resonance (DSR) regime or noise-like pulse (NLP) regime with tunable pulse width. The DSR pulses exhibit characteristic narrowband spectrum, while the NLPs exhibit large broadband spectrum. The operation regime of the laser can be controlled by adjusting the amplifier pump powers and the polarization controllers. To the best of the authors' knowledge, this is the first demonstration of a single mode-locked cavity where narrowband DSR pulses and broadband NLPs alongside Q-ML pulse bunches can be selectively generated by employing two NALMs.

  14. Modes of Operation of the BKCa Channel β2 Subunit

    Science.gov (United States)

    Savalli, Nicoletta; Kondratiev, Andrei; de Quintana, Sarah Buxton; Toro, Ligia; Olcese, Riccardo

    2007-01-01

    The β2 subunit of the large conductance Ca2+- and voltage-activated K+ channel (BKCa) modulates a number of channel functions, such as the apparent Ca2+/voltage sensitivity, pharmacological and kinetic properties of the channel. In addition, the N terminus of the β2 subunit acts as an inactivating particle that produces a relatively fast inactivation of the ionic conductance. Applying voltage clamp fluorometry to fluorescently labeled human BKCa channels (hSlo), we have investigated the mechanisms of operation of the β2 subunit. We found that the leftward shift on the voltage axis of channel activation curves (G(V)) produced by coexpression with β2 subunits is associated with a shift in the same direction of the fluorescence vs. voltage curves (F(V)), which are reporting the voltage dependence of the main voltage-sensing region of hSlo (S4-transmembrane domain). In addition, we investigated the inactivating mechanism of the β2 subunits by comparing its properties with the ones of the typical N-type inactivation process of Shaker channel. While fluorescence recordings from the inactivated Shaker channels revealed the immobilization of the S4 segments in the active conformation, we did not observe a similar feature in BKCa channels coexpressed with the β2 subunit. The experimental observations are consistent with the view that the β2 subunit of BKCa channels facilitates channel activation by changing the voltage sensor equilibrium and that the β2-induced inactivation process does not follow a typical N-type mechanism. PMID:17591990

  15. Modes of operation of the BKCa channel beta2 subunit.

    Science.gov (United States)

    Savalli, Nicoletta; Kondratiev, Andrei; de Quintana, Sarah Buxton; Toro, Ligia; Olcese, Riccardo

    2007-07-01

    The beta(2) subunit of the large conductance Ca(2+)- and voltage-activated K(+) channel (BK(Ca)) modulates a number of channel functions, such as the apparent Ca(2+)/voltage sensitivity, pharmacological and kinetic properties of the channel. In addition, the N terminus of the beta(2) subunit acts as an inactivating particle that produces a relatively fast inactivation of the ionic conductance. Applying voltage clamp fluorometry to fluorescently labeled human BK(Ca) channels (hSlo), we have investigated the mechanisms of operation of the beta(2) subunit. We found that the leftward shift on the voltage axis of channel activation curves (G(V)) produced by coexpression with beta(2) subunits is associated with a shift in the same direction of the fluorescence vs. voltage curves (F(V)), which are reporting the voltage dependence of the main voltage-sensing region of hSlo (S4-transmembrane domain). In addition, we investigated the inactivating mechanism of the beta(2) subunits by comparing its properties with the ones of the typical N-type inactivation process of Shaker channel. While fluorescence recordings from the inactivated Shaker channels revealed the immobilization of the S4 segments in the active conformation, we did not observe a similar feature in BK(Ca) channels coexpressed with the beta(2) subunit. The experimental observations are consistent with the view that the beta(2) subunit of BK(Ca) channels facilitates channel activation by changing the voltage sensor equilibrium and that the beta(2)-induced inactivation process does not follow a typical N-type mechanism.

  16. Various phenomena of self-mode-locked operation in optically pumped semiconductor lasers

    Science.gov (United States)

    Tsou, C. H.; Liang, H. C.; Huang, K. F.; Chen, Y. F.

    2017-02-01

    This work presents several optical experiments to investigate the phenomenon of self-mode locking (SML) in optically pumped semiconductor lasers (OPSLs). First of all, we systematically explore the influence of high-order transverse modes on the SML in an OPSL with a linear cavity. Experimental results reveal that the occurrence of SML can be assisted by the existence of the first high-order transverse mode, and the laser is operated in a well-behaved SML state with the existence of the TEM0,0 mode and the first high-order transverse mode. While more high-order transverse modes are excited, it is found that the pulse train is modulated by more beating frequencies of transverse modes. The temporal behavior becomes the random dynamics when too many high-order transverse modes are excited. We observe that the temporal trace exhibits an intermittent mode-locked state in the absence of high-order transverse modes. In addition to typical mode-locked pulses, we originally observe an intriguing phenomenon of SML in an OPSL related to the formation of bright-dark pulse pairs. We experimentally demonstrated that under the influence of the tiny reflection feedback, the phase locking between lasing longitudinal modes can be assisted to form bright-dark pulse pairs in the scale of round-trip time. A theoretical model based on the multiple reflections in a phase-locked multi-longitudinal-mode laser is developed to confirm the formation of bright-dark pulse pairs.

  17. 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.

  18. Impact of H-mode power threshold on ITER performance and operation

    International Nuclear Information System (INIS)

    Boucher, D.; Mukhovatov, V.

    1996-01-01

    H-mode operation is projected to be needed in ITER in order to achieve its objectives of sustained burn for 1000 s with 1.5 GW of fusion power. However, experiments have shown that a minimum level of input power is required to access and sustain the H-mode regime. This paper studies the impact on ITER operation of the presently available scalings of this minimum input or threshold power for both the direct L-to H- and reverse H- to L-mode transitions. We present scenarios for access into the H-mode, for maintaining the plasma in H-mode and for the fusion power shutdown with the reverse transition into L-mode. The commonly used empirical scaling P thr L-H 0.044n-bar e B T S for the L- to H-mode transition with a reduction of a factor two for the reverse transition has severe consequences on ITER operation and performance and various methods to quantify this impact are presented. We conclude, however, that the ITER mission and physics objectives remain compatible with such a scaling. (author)

  19. 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.

  20. Density Operator Description of Atomic Ordered Spatial Modes in Cavity QED

    OpenAIRE

    Fang, Zhen; Yang, Baoguo; Chen, Xuzong; Zhou, Xiaoji

    2013-01-01

    We present a quantum Monte-Carlo simulation for a pumped atom in a strong coupling cavity with dissipation, where two ordered spatial modes are formed for the atomic probability density, with the peaks distributed either only in the odd sites or only in the even ones of the lattice formed by the cavity field. A mixed state density operator model, which describes the coupling between different atomic spatial modes and the corresponding cavity field components, is proposed, which goes beyond th...

  1. Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation

    Science.gov (United States)

    Firmansyah, Eka; Tomioka, Satoshi; Abe, Seiya; Shoyama, Masahito; Ninomiya, Tamotsu

    This paper proposes a new power-factor-correction (PFC) topology, and explains its operation principle, its control mechanism, related application problems followed by experimental results. In this proposed topology, critical-conduction-mode (CRM) interleaved technique is applied to a bridgeless PFC in order to achieve high efficiency by combining benefits of each topology. This application is targeted toward low to middle power applications that normally employs continuous-conduction-mode boost converter.

  2. 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...

  3. Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sahubar Ali Mohd. Nadhar, E-mail: sahubar@uum.edu.my; Ramli, Razamin, E-mail: razamin@uum.edu.my; Baten, M. D. Azizul, E-mail: baten-math@yahoo.com [School of Quantitative Sciences, UUM College of Arts and Sciences, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

    2015-12-11

    Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers’ efficiency.

  4. Enhanced DEA model with undesirable output and interval data for rice growing farmers performance assessment

    Science.gov (United States)

    Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

    2015-12-01

    Agricultural production process typically produces two types of outputs which are economic desirable as well as environmentally undesirable outputs (such as greenhouse gas emission, nitrate leaching, effects to human and organisms and water pollution). In efficiency analysis, this undesirable outputs cannot be ignored and need to be included in order to obtain the actual estimation of firms efficiency. Additionally, climatic factors as well as data uncertainty can significantly affect the efficiency analysis. There are a number of approaches that has been proposed in DEA literature to account for undesirable outputs. Many researchers has pointed that directional distance function (DDF) approach is the best as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, it has been found that interval data approach is the most suitable to account for data uncertainty as it is much simpler to model and need less information regarding its distribution and membership function. In this paper, an enhanced DEA model based on DDF approach that considers undesirable outputs as well as climatic factors and interval data is proposed. This model will be used to determine the efficiency of rice farmers who produces undesirable outputs and operates under uncertainty. It is hoped that the proposed model will provide a better estimate of rice farmers' efficiency.

  5. Commissioning of two RF operation modes for RF negative ion source experimental setup at HUST

    Science.gov (United States)

    Li, D.; Chen, D.; Liu, K.; Zhao, P.; Zuo, C.; Wang, X.; Wang, H.; Zhang, L.

    2017-08-01

    An RF-driven negative ion source experimental setup, without a cesium oven and an extraction system, has been built at Huazhong University of Science and Technology (HUST). The working gas is hydrogen, and the typical operational gas pressure is 0.3 Pa. The RF generator is capable of delivering up to 20 kW at 0.9 - 1.1 MHz, and has two operation modes, the fixed-frequency mode and auto-tuning mode. In the fixed-frequency mode, it outputs a steady RF forward power (Pf) at a fixed frequency. In the auto-tuning mode, it adjusts the operating frequency to seek and track the minimum standing wave ratio (SWR) during plasma discharge. To achieve fast frequency tuning, the RF signal source adopts a direct digital synthesizer (DDS). To withstand high SWR during the discharge, a tetrode amplifier is chosen as the final stage amplifier. The trend of maximum power reflection coefficient |ρ|2 at plasma ignition is presented at the fixed frequency of 1.02 MHz with the Pf increasing from 5 kW to 20 kW, which shows the maximum |ρ|2 tends to be "steady" under high RF power. The experiments in auto-tuning mode fail due to over-current protection of screen grid. The possible reason is the relatively large equivalent anode impedance caused by the frequency tuning. The corresponding analysis and possible solution are presented.

  6. 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

  7. Single mode operation of a tea CO2 laser by a CW CO2 laser radiation injection

    International Nuclear Information System (INIS)

    Silakhori, K.; Soltanmoradi, F.; Behjat, A.; Montazerghaem, M.; Sadr, R.

    2005-01-01

    In this research work, single mode operation based on injection of a CW laser beam into TEA CO 2 laser cavity has been demonstrated. The technique has vast applications in research programs for laser spectroscopy and optical pumping. The observed smooth pulse shapes indicated that the system is operating in a single mode of operation, where no additional PZT mounted elements or other cavity stabilizing devices have been used. In addition, it have been observed that the output energy has not been reduced when the laser was operating in a single mode of operation, compared with the case when the laser is operating in the multi-mode regime

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

    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 and vice versa for a single phase microgrid made up from voltage controlled voltage source inverters (VC-VSIs) and current controlled voltage source inverters (CC-VSIs) working together in both modes of operation. The primary control structures for the VC-VSIs and CC-VSIs is considered together...... 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....

  15. 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.

  16. Method and apparatus for delegation of secure operating mode access privilege from processor to peripheral

    NARCIS (Netherlands)

    Bosch, H.G.P.; McLellan Jr, Hubert Rae; Mullender, Sape J.

    2007-01-01

    In a processing system comprising a processor and a plurality of peripherals coupled to the processor, access privileges of a secure operating mode of the processor are delegated to at least a given one of the peripherals. The given peripheral is configured to store, in a secure portion of that

  17. 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...

  18. 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

  19. 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...

  20. ABOUT NOTION OF MEASUREMENT RELIABILITY WHEN MONITORING OPERATION MODES OF POWER UNITS

    Directory of Open Access Journals (Sweden)

    V. A. Anishchenko

    2005-01-01

    Full Text Available Monitoring process of measurement reliability in respect of variables that characterize operation modes of power units is investigated in the paper. Control algorithms based on the minimax criterion have been developed. These algorithms take into account the uncertainty in the notion of measurement reliability, the probability distribution laws for the variables under control, and the values of monitoring errors.

  1. Choice of mode of operations of the thermoelectrical cooling device, ensuring the minimal failure rate

    Directory of Open Access Journals (Sweden)

    Zaikov V. P.

    2008-04-01

    Full Text Available A comparative analysis of TCD reliability has been carried out for different current modes. The paper presents relations allowing to determine the relative value of the operating current at a predetermined temperature difference, which provides the minimum failure rate. The possibility of predicting the reliability of devices at the design stage is shown.

  2. 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)

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

    Science.gov (United States)

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

    2015-03-01

    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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Developing the Chalk River Superconducting Cyclotron for operation in π-mode

    International Nuclear Information System (INIS)

    Hulbert, J.A.; Zhou, X.-H.

    1991-01-01

    The Chalk River Superconducting Cyclotron operates in two rf modes. In the π-mode, the voltages on the four dees move in opposition in adjacent dees, giving rise to high rf surface currents in the cavity wall under the magnetic hills, and to vertical asymmetries in the dee excitation. Studies on a half-scale rf model of the accelerating cavity have confirmed the current distribution and the magnitude of the vertical asymmetries. Cavity cooling provided in the initial design required augmentation for π-mode operation, but the magnet cryostat prevents access to the outside of the cavity. Additional cooling has been installed with cooling lines passing through high-rf-field regions to demountable cooling plates. Concurrently, instrumentation leads have been added to provide extra diagnostics of beam trajectories entering the extraction system. The added cooling has enabled operation of the cyclotron up to 65% of design rf power at the highest π-mode frequency, permitting acceleration up to a specific energy of 50 MeV/u, close to the magnetic focusing limit of the cyclotron

  9. 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.)

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. On exact and approximated formulations for scaling-mode shapes in operational modal analysis by mass and stiffness change

    DEFF Research Database (Denmark)

    López-Aenlle, Manuel; Brincker, Rune; Pelayo, F.

    2012-01-01

    When operational modal analysis (OMA) is used to estimate modal parameters, mode shapes cannot be mass normalized. In the past few years, some equations have been proposed to scale mode shapes using the mass-change method, which consists of repeating modal testing after changing the mass at diffe...... simulations were carried out using a plate with closely spaced modes....

  16. 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.

  17. 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.)

  18. 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)

  19. Three modes of a direct-current plasma jet operated underwater to degrade methylene blue

    Science.gov (United States)

    Xuechen, LI; Biao, WANG; Pengying, JIA; Linwei, YANG; Yaru, LI; Jingdi, CHU

    2017-11-01

    A direct-current air plasma jet operated underwater presents three stable modes including an intermittently-pulsed discharge, a periodically-pulsed discharge and a continuous discharge with increasing the power voltage. The three discharge modes have different appearances for the plasma plumes. Moreover, gap voltage-current characteristics indicate that the continuous discharge is in a normal glow regime. Spectral lines from reactive species (OH, N2, N2 +, H α , and O) have been revealed in the emission spectrum of the plasma jet operated underwater. Spectral intensities emitted from OH radical and oxygen atom increase with increasing the power voltage or the gas flow rate, indicating that reactive species are abundant. These reactive species cause the degradation of the methylene blue dye in solution. Effects of the experimental parameters such as the power voltage, the gas flow rate and the treatment time are investigated on the degradation efficiency. Results indicate that the degradation efficiency increases with increasing the power voltage, the gas flow rate or the treatment time. Compared with degradation in the intermittently-pulsed mode or the periodically-pulsed one, it is more efficient in the continuous mode, reaching 98% after 21 min treatment.

  20. 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

  1. 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.

  2. 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....

  3. Use of Segmented Cell Operated in Hydrogen Recirculation Mode to Detect Water Accumulation in PEMFC

    OpenAIRE

    Perez, L.C.; Ihonen J.; J. M. Sousa; Adélio Mendes

    2013-01-01

    Adequate water management is crucial to increase stability and durability of Polymer Electrolyte Membrane Fuel Cells. In this paper, a test rig suitable for water balance and nitrogen crossover studies was built around a hydrogen-air segmented cell and used to indirectly assess flooding or drying conditions in specific zones of the active cell area. In particular, the anode of the segmented cell was operated in recirculation mode with continuous water removal. Current density distribution (CD...

  4. Performances of Resistive Plate chamber Operated in Avalanche Mode under 137Cs Irradiation

    CERN Document Server

    Abbrescia, Marcello; Gianini, Gabriele; Iaselli, Giuseppe; Maggi, Marcello; Marangelli, Bartolomeo; Natali, Sergio; Nuzzo, Salvatore; Ranieri, Antonio; Ratti, Sergio P; Romano, Francesco; Vitulo, Paolo

    1997-01-01

    A 2 mm gas RPC with bakelite plates has been operated in avalanche mode under 137Cs source irradiation. We report on measurements of the efficiency in cosmic rays detection and of the charge developed in the gap, performed for different gas mixtures. We show that C2H2F4 based mixtures exhibit a wide full efficiency plateau with low streamer probability, while the argon based mixtures allow to reduce the detector power consumption

  5. Design of directional prism resonator made DPL operate in TEM00 mode with thermal stability

    Science.gov (United States)

    Lu, Changyong; Wang, Xiaobing; Sun, Bin; Guo, Yanlong; Wang, Guchang; Lin, Yi; Wan, Qiang

    2005-01-01

    An alignment-free directional prism resonator that ensures the laser TEM00 mode with thermal stability in a certain range is designed by using g* parameter equivalent method. The output of all solid state laser is about of 150mJ, and the beam divergence is of 3mrad with 20Hz repetition rate, moreover, when the laser operates from 10 to 30Hz, the beam divergence is steady. This laser meets the needs of special engineering application.

  6. Ablation behaviors of carbon reinforced polymer composites by laser of different operation modes

    Science.gov (United States)

    Wu, Chen-Wu; Wu, Xian-Qian; Huang, Chen-Guang

    2015-10-01

    Laser ablation mechanism of Carbon Fiber Reinforced Polymer (CFRP) composite is of critical meaning for the laser machining process. The ablation behaviors are investigated on the CFRP laminates subject to continuous wave, long duration pulsed wave and short duration pulsed wave lasers. Distinctive ablation phenomena have been observed and the effects of laser operation modes are discussed. The typical temperature patterns resulted from laser irradiation are computed by finite element analysis and thereby the different ablation mechanisms are interpreted.

  7. 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.

  8. 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.

  9. 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.

  10. Risk informed evaluation of allowed outage times considering several modes of plant operation

    International Nuclear Information System (INIS)

    Cepin, M.; Martorell, S.; Villanueva, J. F.; Carlos, S.; Sanchez, A.I.

    2001-01-01

    The methods for assessment of risk have been increasingly used in a decision-making. The objective of this paper is to extend the method for risk informed evaluation of allowed outage times (AOTs), which considers the plant power operation. Such extension allows consideration of several modes of plant operation or plant configurations. Two methods were developed. Results show that better methods and more data included into the models may reduce the conservatism in the evaluations and may contribute to increased flexibility about decisions on AOT.(author)

  11. 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

  12. 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

  13. Energy balance affected by electrolyte recirculation and operating modes in microbial fuel cells.

    Science.gov (United States)

    Jacobson, Kyle S; Kelly, Patrick T; He, Zhen

    2015-03-01

    Energy recovery and consumption in a microbial fuel cell (MFC) can be significantly affected by the operating conditions. This study investigated the effects of electrolyte recirculation and operation mode (continuous vs sequence batch reactor) on the energy balance in a tubular MFC. It was found that decreasing the anolyte recirculation also decreased the energy recovery. Because of the open environment of the cathode electrode, the catholyte recirculation consumed 10 to 50 times more energy than the anolyte recirculation, and resulted in negative energy balances despite the reduction of the anolyte recirculation. Reducing the catholyte recirculation to 20% led to a positive energy balance of 0.0288 kWh m(-3). The MFC operated as a sequence batch reactor generated less energy and had a lower energy balance than the one with continuous operation. Those results encourage the further development of MFC technology to achieve neutral or even positive energy output.

  14. Artificial Neural Networks for New Operating Modes Determination for Variable Energy Cyclotron

    International Nuclear Information System (INIS)

    Abd El- Kawy, M.; Ismail, M.Sh.; Abdel-Bary, M.; Ouda, M.M.

    2012-01-01

    An artificial neural network System (ANNS) has been designed to determine the required parameters for new Operating Modes for the MGC 20 cyclotron operation. The inputs of the ANN are the required beam parameters (the particle name, the particle energy, the beam intensity and the duty factor). The outputs of the ANN are the value of the required parameters that will be applied by the cyclotron operator to the cyclotron elements or devices. These elements are the magnetic lenses, the magnetic correctors, the concentric coils, and the harmonic coils. Four ANN have been used. The input signals are distributed to the Four ANN inputs. The outputs of the Four ANN will be calibrated and then directly applied by the operator to produce the required beam. A three layers ANN structure has been used and the feed forward back propagation algorithm has been used for training. The MATLAB software has been used to simulate the ANN structure

  15. 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

  16. 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

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

    CERN Document Server

    Verbitskaya, E; Ilyashenko, Yu S; Li, Z; Härkönen, J; Tuovinen, E; Luukka, Panja

    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. Considerati...

  18. 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.

  19. 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

  20. 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.

  1. Large Mode Area Single Trench Fiber for 2 mu m Operation

    DEFF Research Database (Denmark)

    Jain, Deepak; Sahu, Jayanta K.

    2016-01-01

    to 25 cm bend radius, respectively, by exploiting high delocalization of the higher order modes. Achievement of a large effective-area can be very useful to address nonlinear effects. Moreover, single trench fiber offers certain advantages such as low-cost fabrication and easy postprocessing (such......Performance of single trench fibers has been investigated using finite-element method at 2 mu m wavelength. Numerical investigations show that an effective single mode operation for large effective area between 3000-4000 mu m(2) and 2000-3000 mu m(2) can be achieved at similar to 40 and similar...... as cleaving and splicing) thanks to the all-solid fiber design....

  2. 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.

  3. 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.

  4. 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.

  5. AP600 Rod Ejection Accident Analysis Under Low Power Operating Mode

    International Nuclear Information System (INIS)

    Sutando, Tegas

    2000-01-01

    AP600 is one of PWRs type reactors being developed by Westinghouse. It was designed to have a Rapid Power Reduction System (RPRS) in its Operating and Control System which enable it to operate under low power level condition, i.e. below 50% of rated power, following a great load rejection (>50%). with this feature, it is important to conduct some safety analysis for this low power operating condition, the same as those normally imposed to the normal power operating condition including the case of Rod Ejection Accident. This paper presents the result of analysis relating with the Rod Ejection case under low power operating mode (RPRS is in operation), as part of preliminary studies for the feasibility of the implementation of the RPRS. There are two main points to be investigated in this analysis i.e., the fuel integrity and the Shutdown Capability of the available control rods. This was performed through the observation of the Maximum Linear Power (MLP) arised following Rod Ejection event and through the Subcriticality test. The results indicate that the resulted MLP was still far below the maximum design limit for transient conditions, assuring the fuel integrity and the available rods could still bring the reactor to subcritical condition following the Rod Ejection event

  6. Paradox phenomena of proton exchange membrane fuel cells operating under dead-end anode mode

    Science.gov (United States)

    Jiang, Dong; Zeng, Rong; Wang, Shumao; Jiang, Lijun; Varcoe, John R.

    2014-11-01

    By using two spatially separated reference electrodes in a single cell proton-exchange membrane fuel cell (PEMFC), the individual potentials of the anode and cathode are recorded under realistic operating conditions. The PEMFC is operated under dead-end anode (DEA) mode, without any humidification, to mitigate water accumulation at the anode. Although N2 crossover from cathode to anode may play an important role in PEMFCs operating under DEA mode, our results unexpectedly show that the over-potentials of both the anode and cathode concomitantly increased or decreased at the same time. The increases of over-potentials correlate to the increase of the high frequency resistance of the cell (Rhf) imply that the water content in the membrane electrode assemblies is critical. However, the subsequent H2 depletion tests suggest that water may accumulate at the interface between the surface of the catalyst and the ultrathin perfluorosulfonic acid (PFSA) ionomer film and this contradicts the above (the increase in Rhf implies the drying out of the MEAs). This study highlights the need for further research into understanding the water transport properties of the ultrathin PFSA ionomer film (<60 nm): it is clear that these exhibit completely different properties to that of bulk proton-exchange membranes (PEM).

  7. Multicriteria hierarchical iterative interactive algorithm for organizing operational modes of large heat supply systems

    Science.gov (United States)

    Korotkova, T. I.; Popova, V. I.

    2017-11-01

    The generalized mathematical model of decision-making in the problem of planning and mode selection providing required heat loads in a large heat supply system is considered. The system is multilevel, decomposed into levels of main and distribution heating networks with intermediate control stages. Evaluation of the effectiveness, reliability and safety of such a complex system is carried out immediately according to several indicators, in particular pressure, flow, temperature. This global multicriteria optimization problem with constraints is decomposed into a number of local optimization problems and the coordination problem. An agreed solution of local problems provides a solution to the global multicriterion problem of decision making in a complex system. The choice of the optimum operational mode of operation of a complex heat supply system is made on the basis of the iterative coordination process, which converges to the coordinated solution of local optimization tasks. The interactive principle of multicriteria task decision-making includes, in particular, periodic adjustment adjustments, if necessary, guaranteeing optimal safety, reliability and efficiency of the system as a whole in the process of operation. The degree of accuracy of the solution, for example, the degree of deviation of the internal air temperature from the required value, can also be changed interactively. This allows to carry out adjustment activities in the best way and to improve the quality of heat supply to consumers. At the same time, an energy-saving task is being solved to determine the minimum required values of heads at sources and pumping stations.

  8. NUR research reactor safety analysis study for long time natural convection (NC) operation mode

    International Nuclear Information System (INIS)

    Azzoune, M.; Mammou, L.; Boulheouchat, M.H.; Zidi, T.; Mokeddem, M.Y.; Belaid, S.; Bousbia Salah, A.; Meftah, B.; Boumedien, A.

    2010-01-01

    The current work represents a part of an overall effort being undertaken to improve NUR nuclear research reactor neutron utilization capabilities using a new core configuration. A RELAP5 model for the reactor NUR under natural convection (NC) operating mode has been developed. The model represents internal pool reactor components with the corresponding geometry, point neutron kinetics, and thermal hydraulics characteristics. An experimental device was designed and implemented in the reactor pool for monitoring the inlet and outlet core temperatures, and other pool temperature positions during NC-operating mode. In this paper, unprotected fast reactivity insertion and total flow blockage of the flapper valve transients have been investigated under NC operating conditions. The achieved steady-state results were found to be in good qualitative agreement with measurements. The results obtained from the transient (FRIA) study were compared to similar approach from recent literature. The second transient herein considered, is an attempt to predict the reactor core thermal-hydraulic behavior under a total flow blockage of the (NC) flapper valve. The latter could be considered as useful contribution for updating the safety analysis report.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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.

  14. Formation of multiple subpulses in a free-electron laser operating in the limit-cycle mode

    NARCIS (Netherlands)

    Knippels, G.M.H.; van der Meer, A. F. G.; R F X A M Mols,; Oepts, D.; van Amersfoort, P. W.

    1996-01-01

    The evolution of the longitudinal pulse shape and the spectrum of the short-pulse, far-infrared free-electron laser FELIX are investigated. Depending on the amount of cavity desynchronization applied, the laser is found to operate in the stable-focus mode or in the limit-cycle mode. In the latter

  15. Threshold condition for nonlinear tearing modes in tokamaks

    International Nuclear Information System (INIS)

    Zabiego, M.F.; Callen, J.D.

    1996-03-01

    Low-mode-number tearing, mode nonlinear evolution is analyzed emphasizing the need for a threshold condition, to account for observations in tokamaks. The discussion is illustrated by two models recently introduced in the literature. The models can be compared with the available data and/or serve as a basis for planning some experiments in order to either test theory (by means of beta-limit scaling laws, as proposed in this paper) or attempt to control undesirable tearing modes. Introducing a threshold condition in the tearing mode stability analysis is found to reveal some bifurcation points and thus domains of intrinsic stability in the island dynamics operational space

  16. Reactor issues for tandem mirrors operating in the negative-potential mode

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, L.J.; Campbell, R.B.

    1985-12-02

    During 1985, interest has been revived at LLNL in tandem mirrors operating in the negative-potential mode. The negative tandem is formed by combining ECRH-sustained hot electron end cell plasmas with pumping mechanisms to remove trapped ions from the end cells. No sloshing ions are required. The resulting negative potential in the end cells confines the central cell electrons. The requirement of charge neutrality causes the ambipolar potential of the central cell to become negative relative to the end wall (hence, the name ''negative' tandem mirror), thereby providing central cell ion confinement. This potential distribution is the exact inverse of the axial distribution for the conventional (positive) tandem mirror without thermal barriers. In the negative tandem mirror, central cell electrons are confined electrostatically, end cell electrons are confined magnetically, and ions are confined electrostatically everywhere. In this report, we briefly assess the reactor issues pertinent to the operation of the tandem mirror in the negative mode. 7 refs., 5 figs.

  17. 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.

  18. Development of Data Envelopment Analysis for the Performance Evaluation of Green Supply Chain with Undesirable Outputs

    Directory of Open Access Journals (Sweden)

    Alireza Alinezhad

    2016-08-01

    Full Text Available A fundamental problem is the use of DEA in multistep or multilevel processes such as supply chain, lack of attention to processes’ internal communications in a way that the recent studies on DEA in the context of serial processes have focused on closed systems that the outputs of one level become the inputs of the next level and none of the inputs enter the mediator process. The present study aimed to examine the general dimensions of an open multilevel process. Here, some of the data such as inputs and outputs are supposed to leave the system while other outputs turn into the inputs of the next level. The new inputs can enter the next level as well. We expand this mode for network structures. The overall performance of such a structure is considered as a weighted average of sectors’ performance or distinct steps. Therefore, this suggested model in this study, not only provides the possibility to evaluate the performance of the entire network, but creates the performance analysis for each of the sub-processes. On the other hand, considering the data with undesirable structure leads to more correct performance estimation. In the real world, all productive processes do not comprise desirable factors. Therefore, presenting a structure that is capable of taking into account the undesirable structure is of crucial importance. In this study, a new model in the DEA by network structure is offered that can analyze the performance considering undesirable factors.

  19. 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

  20. Rice growing farmers efficiency measurement using a slack based interval DEA model with undesirable outputs

    Science.gov (United States)

    Khan, Sahubar Ali Mohd. Nadhar; Ramli, Razamin; Baten, M. D. Azizul

    2017-11-01

    In recent years eco-efficiency which considers the effect of production process on environment in determining the efficiency of firms have gained traction and a lot of attention. Rice farming is one of such production processes which typically produces two types of outputs which are economic desirable as well as environmentally undesirable. In efficiency analysis, these undesirable outputs cannot be ignored and need to be included in the model to obtain the actual estimation of firm's efficiency. There are numerous approaches that have been used in data envelopment analysis (DEA) literature to account for undesirable outputs of which directional distance function (DDF) approach is the most widely used as it allows for simultaneous increase in desirable outputs and reduction of undesirable outputs. Additionally, slack based DDF DEA approaches considers the output shortfalls and input excess in determining efficiency. In situations when data uncertainty is present, the deterministic DEA model is not suitable to be used as the effects of uncertain data will not be considered. In this case, it has been found that interval data approach is suitable to account for data uncertainty as it is much simpler to model and need less information regarding the underlying data distribution and membership function. The proposed model uses an enhanced DEA model which is based on DDF approach and incorporates slack based measure to determine efficiency in the presence of undesirable factors and data uncertainty. Interval data approach was used to estimate the values of inputs, undesirable outputs and desirable outputs. Two separate slack based interval DEA models were constructed for optimistic and pessimistic scenarios. The developed model was used to determine rice farmers efficiency from Kepala Batas, Kedah. The obtained results were later compared to the results obtained using a deterministic DDF DEA model. The study found that 15 out of 30 farmers are efficient in all cases. It

  1. Measuring derived acoustic power of an ultrasound surgical device in the linear and nonlinear operating modes.

    Science.gov (United States)

    Petosić, Antonio; Ivancević, Bojan; Svilar, Dragoljub

    2009-06-01

    The method for measuring derived acoustic power of an ultrasound point source in the form of a sonotrode tip has been considered in the free acoustic field, according to the IEC 61847 standard. The main objective of this work is measuring averaged pressure magnitude spatial distribution of an sonotrode tip in the free acoustic field conditions at different electrical excitation levels and calculation of the derived acoustic power at excitation frequency (f0 approximately 25 kHz). Finding the derived acoustic power of an ultrasonic surgical device in the strong cavitation regime of working, even in the considered laboratory conditions (anechoic pool), will enable better understanding of the biological effects on the tissue produced during operation with the considered device. The pressure magnitude spatial distribution is measured using B&K 8103 hydrophone connected with a B&K 2626 conditioning amplifier, digital storage oscilloscope LeCroy Waverunner 474, where pressure waveforms in the field points are recorded. Using MATLAB with DSP processing toolbox, averaged power spectrum density of recorded pressure signals in different field positions is calculated. The measured pressure magnitude spatial distributions are fitted with the appropriate theoretical models. In the linear operating mode, using the acoustic reciprocity principle, the sonotrode tip is theoretically described as radially oscillating sphere (ROS) and transversely oscillating sphere (TOS) in the vicinity of pressure release boundary. The measured pressure magnitude spatial distribution is fitted with theoretical curves, describing the pressure field of the considered theoretical models. The velocity and displacement magnitudes with derived acoustic power of equivalent theoretical sources are found, and the electroacoustic efficiency factor is calculated. When the transmitter is excited at higher electrical power levels, the displacement magnitude of sonotrode tip is increased, and nonlinear behaviour

  2. A two stage data envelopment analysis model with undesirable output

    Science.gov (United States)

    Shariff Adli Aminuddin, Adam; Izzati Jaini, Nur; Mat Kasim, Maznah; Nawawi, Mohd Kamal Mohd

    2017-09-01

    The dependent relationship among the decision making units (DMU) is usually assumed to be non-existent in the development of Data Envelopment Analysis (DEA) model. The dependency can be represented by the multi-stage DEA model, where the outputs from the precedent stage will be the inputs for the latter stage. The multi-stage DEA model evaluate both the efficiency score for each stages and the overall efficiency of the whole process. The existing multi stage DEA models do not focus on the integration with the undesirable output, in which the higher input will generate lower output unlike the normal desirable output. This research attempts to address the inclusion of such undesirable output and investigate the theoretical implication and potential application towards the development of multi-stage DEA model.

  3. A Case of Undesired Bleb Developed After Penetrating Injury

    Directory of Open Access Journals (Sweden)

    Cem Ozgonul

    2014-03-01

    Full Text Available Eighty-year-old male patient was admitted to our policlinic with stinging, burning and itching in both eyes. Ophthalmological examination revealed avascular undesired bleb that releated with anterior chamber at 2-3 hour quadrant nasal limbus with the surrounding corneal and conjunctival epithelium was vascularized and the dimension was 3x3x3 mm. Towards these findings, we questioned the patient again and we found that, 40 years ago, a broken part of the shaving razor had injured his eye. After penetrating injury of the eye, because of the sutured wound leakage, undesired bleb formations can be seen. We suggest that kind of patient shold be followed up to prevent late complications of penetrating injury.

  4. 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.

  5. End Suction Centrifugal Pump Operating in Turbine Mode for Microhydro Applications

    Directory of Open Access Journals (Sweden)

    Mohd Azlan Ismail

    2014-03-01

    Full Text Available This paper reviews the current research works on the end suction centrifugal pump coupled with induction generator running in turbine mode for microhydro application. The information can be used by practicing engineers, researchers, and plant managers to understand the potential of pump running as turbine. Review on experimental and simulation works was carried out encompassing end suction single stage low specific speed which is less than 10 kW. This is followed by review of their efficiency improvement through modifications. The results show that centrifugal pump can operate in turbine modes without any modification on mechanical components. However, to achieve the best efficiency point (BEP, it requires higher flow rate and head than pumping rating. Efficiency improvement is viable through geometric modification to improve hydraulic characteristic. The studies also show that pump as turbine (PAT can be directly coupled with modified induction motor as generator by adding capacitor and electric control system, regulating voltage and frequency at the output terminal. It was found that PAT offers the best low cost solution for microhydro application especially for third world countries that do not have local microhydro manufacturer.

  6. 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.

  7. 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)

  8. Transient validation of RELAP5 model with the DISS facility in once through operation mode

    Science.gov (United States)

    Serrano-Aguilera, J. J.; Valenzuela, L.

    2016-05-01

    Thermal-hydraulic code RELAP5 has been used to model a Solar Direct Steam Generation (DSG) system. Experimental data from the DISS facility located at Plataforma Solar de Almería is compared to the numerical results of the RELAP5 model in order to validate it. Both the model and the experimental set-up are in once through operation mode where no injection or active control is regarded. Time dependent boundary conditions are taken into account. This work is a preliminary study of further research that will be carried out in order to achieve a thorough validation of RELAP5 models in the context of DSG in line-focus solar collectors.

  9. On the zero modes of the Faddeev-Popov operator in the Landau gauge

    Energy Technology Data Exchange (ETDEWEB)

    Landim, R. R., E-mail: renan@fisica.ufc.br [Instituto de Física, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, Maracanã, Rio de Janeiro, RJ 20550-013 (Brazil); Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-760, Fortaleza, Ceará (Brazil); Vilar, L. C. Q., E-mail: lcqvilar@gmail.com; Lemes, V. E. R., E-mail: vitor@dft.if.uerj.br [Instituto de Física, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, Maracanã, Rio de Janeiro, RJ 20550-013 (Brazil); Ventura, O. S., E-mail: ozemar.ventura@cefet-rj.br [Centro Federal de Educação Tecnológica do Rio de Janeiro, Av. Maracanã 249, 20271-110, Rio de Janeiro, RJ (Brazil)

    2014-02-15

    Following Henyey procedure [Phys. Rev. D 20, 1460 (1979)], we construct examples of zero modes of the Faddeev-Popov operator in the Landau gauge in Euclidean space in D dimensions, for both SU(2) and SU(3) groups. We obtain gauge field configurations A{sub μ}{sup a} which give rise to a field strength, F{sub μν}{sup a}=∂{sub μ}A{sub ν}{sup a}−∂{sub ν}A{sub μ}{sup a}+f{sup abc}A{sub μ}{sup b}A{sub ν}{sup c}, whose nonlinear term, f{sup abc}A{sub μ}{sup b}A{sub ν}{sup c}, turns out to be non-vanishing. To our knowledge, this is the first time where such a non-abelian configuration is explicitly obtained in the case of SU(3) in 4D.

  10. 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.

  11. A simple operator check of the effective fermion mode function during inflation

    Energy Technology Data Exchange (ETDEWEB)

    Miao, S P [Institute for Theoretical Physics and Spinoza Institute, Utrecht University Leuvenlaan 4, Postbus 80.195, 3508 TD Utrecht (Netherlands); Woodard, R P [Department of Physics, University of Florida Gainesville, FL 32611 (United States)], E-mail: S.P.Miao@phys.uu.nl, E-mail: woodard@phys.ufl.edu

    2008-07-21

    We present a relatively simple operator formalism which reproduces the leading infrared logarithm of the one-loop quantum gravitational correction to the fermion mode function on a locally de Sitter background. This rule may serve as the basis for an eventual stochastic formulation of quantum gravity during inflation. Such a formalism would not only effect a vast simplification in obtaining the leading powers of ln(a) at fixed loop orders, but also permit us to sum the series of leading logarithms. A potentially important point is that our rule does not seem to be consistent with any simple infrared truncation of the fields. Our analysis also highlights the importance of spin as a gravitational interaction that persists even when kinetic energy has redshifted to zero.

  12. 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.

  13. Cycles of undesirable substances in the food chain

    International Nuclear Information System (INIS)

    2012-01-01

    The working group ''Carry over of undesirable substances in animal feed'' at the Federal Ministry of Food, Agriculture and Forestry (BMELV) in cooperation with the Institute of Animal Nutrition of the Friedrich-Loeffler-Institute (FLI) performed on 27 and 28 October 2011 in Braunschweig a workshop on ''cycles of undesirable substances in Food Chain ''. The aim of the workshop was to present the latest findings of research and Carry over Recommendations of the Carry over - Working Group on undesirable substances in feed and production processes of the feed industry, to evaluate and discuss about this with representatives from science, business and management and to work out the further research and action need. The focus of the considerations were the pathways, the carry over and the Exposure to dioxins and other halogenated hydrocarbons, the effects of Mycotoxins in feed and starting points for preventive measures, the soil contamination and the exposure of humans and animals by cadmium and case studies on Nitrite in feed, antibiotics in plants and residues of pesticides and radionuclides in feed. Furthermore the risks associated with specified manufacturing processes of feed are considered, especially the used materials that come into contact with animal feed, and the risks from nanotechnology. [de

  14. 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

  15. 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.

  16. Efficient AlGaN/GaN Linear and Digital-Switch-Mode Power Amplifiers for Operation at 2GHz

    Science.gov (United States)

    Maroldt, Stephan; Wiegner, Dirk; Vitanov, Stanislav; Palankovski, Vassil; Quay, Rüdiger; Ambacher, Oliver

    This work addresses the enormous efficiency and linearity potential of optimized AlGaN/GaN high-electron mobility transistors (HEMT) in conventional Doherty linear base-station amplifiers at 2.7GHz. Supported by physical device simulation, the work further elaborates on the use of AlGaN/GaN HEMTs in high-speed current-switch-mode class-D (CMCD)/class-S MMICs for data rates of up to 8Gbit/s equivalent to 2GHz RF-operation. The device needs for switch-mode operation are derived and verified by MMIC results in class-S and class-D operation. To the authors' knowledge, this is the first time 2GHz-equivalent digital-switch-mode RF-operation is demonstrated with GaN HEMTs with high efficiency.

  17. 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

  18. Continuous countercurrent tangential chromatography for mixed mode post-capture operations in monoclonal antibody purification.

    Science.gov (United States)

    Dutta, Amit K; Fedorenko, Dmitriy; Tan, Jasmine; Costanzo, Joseph A; Kahn, David S; Zydney, Andrew L; Shinkazh, Oleg

    2017-08-18

    Continuous Countercurrent Tangential Chromatography (CCTC) has been shown to demonstrate significant advantages over column chromatography including higher productivity, lower operational pressure, disposable flow path, and lower resin use. Previous applications of CCTC have been limited to initial capture of monoclonal antibodies (mAb) from clarified cell culture harvest. In this present article, a CCTC system was designed and tested for a post-capture antibody purification step. Mixed mode cation exchange-hydrophobic interaction chromatography resins with two different particle sizes were used to reduce host cell protein (HCP), leached protein A, DNA, and aggregates from a mAb stream after a protein A operation. Product output from CCTC was obtained at a steady-state concentration in sharp contrast to the periodic output of product in multi-column systems. The results show up to 101g of mAb/L of resin/hr productivity, which is 10× higher than in a batch column. A 5% yield increase (95% with CCTC vs. 90% in batch column) resulted from optimizing elution pH within a narrow operational window (pH 4-4.5). Contaminant removal was found to be similar to conventional column performance. Data obtained with the smaller particle size resin showed faster binding kinetics leading to reduced CCTC system volume and increased productivity. Buffer and water usage were modeled to show potential for utilization of in-line mixing and buffer tank volume reduction. The experimental results were used to perform a scale up exercise that predicts a compact CCTC flow path for 500 and 2000L batches using commercially available membranes. These results demonstrate the potential of using CCTC for post-capture operations as an alternative to packed bed chromatography, and provide a framework for the design and development of an integrated continuous bioprocessing platform based on CCTC technology. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 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

  20. 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.

  1. 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).

  2. 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.

  3. 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

  4. The combination of directional outputs and single-mode operation in circular microdisk with broken PT symmetry.

    Science.gov (United States)

    Song, Qinghai; Li, Jiankai; Sun, Wenzhao; Zhang, Nan; Liu, Shuai; Li, Meng; Xiao, Shumin

    2015-09-21

    Monochromaticity and directionality are two key characteristics of lasers. However, the combination of directional emission and single-mode operation is quite challenging, especially for the on-chip devices. Here we propose a microdisk laser with single-mode operation and directional emissions by exploiting the recent developments associated with parity-time (PT) symmetry. This is accomplished by introducing one-dimensional periodic gain and loss into a circular microdisk, which induces a coupling between whispering gallery modes with different radial numbers. The lowest threshold mode is selected at the positions with least initial wavelength difference. And the directional emissions are formed by the introduction of additional grating vectors by the periodic distribution of gain and loss regions. We believe this research will impact the practical applications of on-chip microdisk lasers.

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

    International Nuclear Information System (INIS)

    Canfora, Fabrizio; Giacomini, Alex; Oliva, Julio

    2010-01-01

    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.

  6. Influence on deep brain stimulation from lead design, operating mode and tissue impedance changes – a simulation study

    OpenAIRE

    Alonso Fabiola; Hemm-Ode Simone; Wardell Karin

    2015-01-01

    Background: Deep brain stimulation (DBS) systems in current mode and new lead designs are recently available. To switch between DBS-systems remains complicated as clinicians may lose their reference for programming. Simulations can help increase the understanding. Objective: To quantitatively investigate the electric field (EF) around two lead designs simulated to operate in voltage and current mode under two time points following implantation. Methods: The finite element method was used to m...

  7. Fourier Domain Mode Locking (FDML): A new laser operating regime and applications for optical coherence tomography.

    Science.gov (United States)

    Huber, R; Wojtkowski, M; Fujimoto, J G

    2006-04-17

    We demonstrate a new technique for frequency-swept laser operation--Fourier domain mode locking (FDML)--and its application for swept-source optical coherence tomography (OCT) imaging. FDML is analogous to active laser mode locking for short pulse generation, except that the spectrum rather than the amplitude of the light field is modulated. High-speed, narrowband optical frequency sweeps are generated with a repetition period equal to the fundamental or a harmonic of cavity round-trip time. An FDML laser is constructed using a long fiber ring cavity, a semiconductor optical amplifier, and a tunable fiber Fabry-Perot filter. Effective sweep rates of up to 290 kHz are demonstrated with a 105 nm tuning range at 1300 nm center wavelength. The average output power is 3mW directly from the laser and 20 mW after post-amplification. Using the FDML laser for swept-source OCT, sensitivities of 108 dB are achieved and dynamic linewidths are narrow enough to enable imaging over a 7 mm depth with only a 7.5 dB decrease in sensitivity. We demonstrate swept-source OCT imaging with acquisition rates of up to 232,000 axial scans per second. This corresponds to 906 frames/second with 256 transverse pixel images, and 3.5 volumes/second with a 256x128x256 voxel element 3-DOCT data set. The FDML laser is ideal for swept-source OCT imaging, thus enabling high imaging speeds and large imaging depths.

  8. 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

  9. Physics and performance of the I-mode regime over an expanded operating space on Alcator C-Mod

    Science.gov (United States)

    Hubbard, A. E.; Baek, S.-G.; Brunner, D.; Creely, A. J.; Cziegler, I.; Edlund, E.; Hughes, J. W.; LaBombard, B.; Lin, Y.; Liu, Z.; Marmar, E. S.; Reinke, M. L.; Rice, J. E.; Sorbom, B.; Sung, C.; Terry, J.; Theiler, C.; Tolman, E. A.; Walk, J. R.; White, A. E.; Whyte, D.; Wolfe, S. M.; Wukitch, S.; Xu, X. Q.; the Alcator C-Mod Team

    2017-12-01

    New results on the I-mode regime of operation on the Alcator C-Mod tokamak are reported. This ELM-free regime features high energy confinement and a steep temperature pedestal, while particle confinement remains at L-mode levels, giving stationary density and avoiding impurity accumulation. I-mode has now been obtained over nearly all of the magnetic fields and currents possible in this high field tokamak (I p 0.55-1.7 MA, B T 2.8-8 T) using a configuration with B  ×  ∇ B drift away from the X-point. Results at 8 T confirm that the L-I power threshold varies only weakly with B T, and that the power range for I-mode increases with B T; no 8 T discharges transitioned to H-mode. Parameter dependences of energy confinement are investigated. Core transport simulations are giving insight into the observed turbulence reduction, profile stiffness and confinement improvement. Pedestal models explain the observed stability to ELMs, and can simulate the observed weakly coherent mode. Conditions for I-H transitions have complex dependences on density as well as power. I-modes have now been maintained in near-DN configurations, leading to improved divertor power flux sharing. Prospects for I-mode on future fusion devices such as ITER and ARC are encouraging. Further experiments on other tokamaks are needed to improve confidence in extrapolation.

  10. Undesirable Effects of Media on Children: Why Limitation is Necessary?

    Science.gov (United States)

    Karaagac, Aysu Turkmen

    2015-06-01

    Pervasive media environment is a social problem shared by most of the countries around the world. Several studies have been performed to highlight the undesired effects of media on children. Some of these studies have focused on the time spent by children watching television, playing with computers or using mobile media devices while some others have tried to explain the associations between the obesity, postural abnormalities or psychological problems of children, and their media use. This article discusses the recent approaches to curb influence of media on children, and the importance of family media literacy education programs with particular relevance to developing countries.

  11. Undesirable substances in vegetable oils: anything to declare?

    Directory of Open Access Journals (Sweden)

    Lacoste Florence

    2014-01-01

    Full Text Available The presence of undesirable compounds in vegetable and animal oils and fats may have many different origins. Although the potential toxicity of most of these undesirable compounds is real, poisoning risks are rather limited due to the efficient elimination during oil-refining steps, careful conditioning, choice of efficient packaging and industrial quality control management. However the research of contaminants is part of multiple controls conducted by fat and oil industry to verify the conformity of products placed on the market in relation to regulations such as the European commission regulation EC No. 1881/2006 setting maximum levels for some contaminants in food as lead, some mycotoxins, dioxins, polychlorobiphenyls, benzo[a]pyrene. In the absence of regulation, the detection of contaminants must be addressed in partnership with authorities according to the toxicity of molecules. The controls are not confined to environmental contaminants. They also include compounds that can be formed during the production process of vegetable oils such as esters of 3-monochloropropanediol. This article focuses more particularly on heavy metals, polycyclic aromatic hydrocarbons, mineral oils, phthalates and 3-MCPD or glycidyl esters. Aspects such as methods for analysis, limits fixed by EC regulation and occurrence in vegetable oils are discussed.

  12. High-power, multioutput piezoelectric transformers operating at the thickness-shear vibration mode.

    Science.gov (United States)

    Du, Jinlong; Hu, Junhui; Tseng, King Jet

    2004-05-01

    In this study, a piezoelectric transformer operating at the thickness shear vibration mode and with dual or triple outputs is proposed. It consists of a lead zirconate titanate (PZT) ceramic plate with a high mechanical quality factor Qm and a size of 120 x 20 x 4 mm3. The PZT ceramic plate is poled along the width direction. The electrodes of input and output parts are on the top and bottom surfaces of the ceramic plate and separated by narrow gaps. A new construction of support and lead wire connection is used for the transformer. At a temperature rise less than 20 degrees C and efficiency of 90%, the piezoelectric transformer with dual outputs has a maximum total output power of 169.8 W, with a power of 129.5 W in one output and 40.3 W in another. The one with triple outputs has a maximum total output power of 163.1 W, with a power of 36.9 W in the first output, 13.0 W in the second output and 113.2 W in the third output. The maximum efficiency of the piezoelectric transformer with dual outputs and triple outputs is 98% and 95.7%, respectively. The voltage gains of the transformers are less than one, and different outputs have different gains. Also, there is a driving frequency range in which the load resistance of one output has little effect on the voltage gain of another output.

  13. RF breakdown in "cold" slow wave structures operating at travelling wave mode of TM01

    Science.gov (United States)

    Yuan, Yuzhang; Zhang, Jun; Zhong, Huihuang; Zhang, Dian; Bai, Zhen; Zhu, Danni

    2018-01-01

    RF breakdown experiments and simulations in "cold" slow wave structures (SWSs) are executed. All the SWSs are designed as traveling wave structures, which operate at the π/2 mode of TM01 waves. The experimental results indicate that the input microwave energy is mainly absorbed, not reflected by the RF breakdown process in traveling wave SWSs. Both larger magnitude of Es-max and more numbers of periods of SWSs aggravate the microwave absorption in the breakdown process and bring about a shorter transmission pulse width. We think that the critical surface E-field of the multi-period SWSs is 1 MV/cm. However, little correlation between RF breakdown effects and Bext is observed in the experiments. The simulation conditions are coincident with the experimental setup. Explosive emissions of electrons in the rounded corner of SWSs together with the ionization of the gas layer close to it supply the breakdown plasma. The gas layer consists of water vapor and hydrogen gas and has a pressure of 1 Pa. Different kinds of circumstances of SWSs are simulated. We mainly concern about the characteristic of the plasma and its influence on microwave power. Comprehensive simulation results are obtained. The simulation results match the experimental results basically and are helpful in explaining the RF breakdown phenomenon physically.

  14. 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.

  15. Performance of Single Electrode-Supported Cells Operating in the Electrolysis Mode

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; G. K. Housley; D. G. Milobar

    2009-11-01

    An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (~10 µm thick), nickel-YSZ steam/hydrogen electrodes (~1400 µm thick), and manganite (LSM) air-side electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 – 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented.

  16. Concentrated microalgae cultivation in treated sewage by membrane photobioreactor operated in batch flow mode.

    Science.gov (United States)

    Gao, Feng; Yang, Zhao-Hui; Li, Chen; Wang, Yu-jie; Jin, Wei-hong; Deng, Yi-bing

    2014-09-01

    This study investigated the microalgae biomass production and nutrients removal efficiency from treated sewage by newly developed membrane photobioreactor in which Chlorella vulgaris was cultured in batch flow mode. Its performance was compared with conventional photobioreactor. The results show that the volumetric microalgae productivity was 39.93 and 10.36 mg L(-1)d(-1) in membrane photobioreactor and conventional photobioreactor, respectively. The nutrients removal rate in membrane photobioreactor was 4.13 mg N L(-1)d(-1) and 0.43 mg P L(-1)d(-1), which was obviously higher than that in conventional photobioreactor (0.59 mg N L(-1)d(-1) and 0.08 mg P L(-1)d(-1)). The better performance of membrane photobioreactor was due to the submerged membrane module in the reactor which acted as a solid-liquid separator and thereby enabled the reactor to operate with higher supply flow rate of cultivation medium. Moreover, in the outflow stage of the membrane photobioreactor, the microalgae culture liquor in the reactor could be further concentrated. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Low Power CMOS Operational Amplifier with Integrated Common-Mode Feedback for Data Converter

    Directory of Open Access Journals (Sweden)

    Murad S.A.Z

    2017-01-01

    Full Text Available The development a high-performance design of analog circuits becomes increasingly challenging with the continuous trend towards reducing the voltage supply and low power consumption without neglecting the trade-off among other performance parameters. This paper presents the design and implementation of CMOS operational amplifier (op-amp with integrated common-mode feedback (CMFB circuit for data converter using 0.13-μm Silterra CMOS technology. The folded cascode topology is employed as a main op-amp design because it provides high gain and high bandwidth besides low power consumption. The simulation results indicate that the DC gain of 64.5 dB along 133.1 MHz unity gain bandwidth (UGB is achieved for a 1 pF load capacitor. The slew rate of 22.6 V/μs, the phase margin (PM of 68.4° with settling time of 72.4 ns are obtained. The power consumption of this op-amp is 0.3 mW through voltage supply of 1.8 V.

  18. Guidelines used in Japan to prevent the contamination of feed products with undesirable substances

    Directory of Open Access Journals (Sweden)

    Katsuaki Sugiura

    2011-01-01

    Full Text Available As Japan depends on imports for most ingredients used to manufacture feed products, close co-operation is indispensable between importers and manufacturers of feed and feed ingredients to effectively mitigate the risk associated with feed safety. Guidelines were issued by the Ministry of Agriculture, Forestry and Fisheries (MAFF in March 2008 to prevent feed products from being contaminated with undesirable substances. These guidelines identify the responsibilities of feed ingredient importers, feed manufacturers and distributors, as well as the roles of the MAFF and the Food and Agricultural Materials Inspection Centre.

  19. Electrochemical cell with the reversible electrode-solid electrolyte or ionic melt interface in galvanodynamic and potentiodynamic operating modes

    Science.gov (United States)

    Guseynov, R. M.; Radzhabov, R. A.; Makhmudov, H. M.; Kelbykhanov, R. K.; Medzhidova, E. A.; Nadirova, R. Y.

    2017-08-01

    This work is aimed at studying the kinetics of the following two simultaneous processes: charging of the double electrical layer and the charge transfer at the reversible silver electrode-sulfate solid electrolyte or corresponding ionic melt interface in two operating modes of electrochemical cell, namely, galvanodynamic and potentiodynamic ones. The electrochemical kinetics has been studied by the method of operational impedance based on the Ohm law of interaction between Laplace transformed current, voltage, and complex resistance (impedance). Using appropriate mathematical calculations, analytical expressions are obtained for the current passing via a cell during linear potential scanning (potentiodynamic mode) as a function of time and for the interface potential as a function of time in the galvanodynamic mode (linear current scanning). The time dependence of the potential of the electrode-solid electrolyte or ionic melt interface is described by an exponential function in the potentiodynamic mode of the cell operation. An analysis and comparison of the results of the two independent electrochemical modes demonstrate that the behavior of the electrochemical cells containing a reversible metallic electrode, i.e., a solid electrolyte or the corresponding ionic melt, obeys the classical Randles-Ershler equivalent circuit. This statement can be proved by both the alternating current method (impedance method) and relaxation galvanodynamic and potentiodynamic methods (linear scanning of potential and current).

  20. Enhanced performance of bio-cathode microbial fuel cells with the applying of transient-state operation modes.

    Science.gov (United States)

    Liang, Peng; Yuan, Lulu; Wu, Wenlong; Yang, Xufei; Huang, Xia

    2013-11-01

    To enhance the MFC's denitrification performance, this study investigated three different external circuits/operation modes of the MFC: alternative charging and discharging (ACD), intermittent charging (IC) and constant external resistance (R). Results showed that the ACD and IC modes offered larger output currents as well as higher nitrate and COD removal rates than the steady R mode. The best performance was achieved with the ACD mode. At the initial [COD]=~1200 mg/L and [NO3(-)]=~140 mg/L, the ACD mode delivered an average power density of 0.91 W/m(3), an average nitrate removal rate of 15.5mg/(Ld) and an average COD removal rate of 137 mg/(Ld), 268%, 207% and 168% respectively greater than those by the R mode. The enhancement by the ACD and IC modes was more pronounced at lower nitrate and COD concentrations and/or with the lack of stirring of electrolyte solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. 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

    This paper presents the development and test of a flexible control strategy for an 11-kw wind turbine with a back-to-back power converter capable of working in both stand-alone and grid-connected mode. The stand-alone control is featured with a complex output voltage controller capable of handling...... 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......-locked loop controller is developed in order to detect the grid failure or recovery and switch the operation mode accordingly. A flexible digital signal processor (DSP) system that allows user-friendly code development and on-line tuning is used to implement and test the different control strategies. The back...

  2. 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)

  3. Tunable single-longitudinal-mode operation of an injection-locked TEA CO2 laser. [ozone absorption spectroscopy

    Science.gov (United States)

    Megie, G.; Menzies, R. T.

    1979-01-01

    The tunable single-longitudinal-mode operation of a TEA CO2 laser by an injection technique using a CW waveguide laser as the master oscillator is reported. With the experimental arrangement described, in which the waveguide laser frequency is tuned to correspond to one of the oscillating longitudinal modes of the TEA laser, single-longitudinal-mode operation was achieved with no apparent reduction in the TEA output energy, on various CO2 lines with frequency offsets from the line center as large as 300 MHz. The capability of this technique for high-resolution spectroscopy or atmospheric lidar studies is demonstrated by the recording of the absorption spectrum of a strong ozone line.

  4. Energy Level of Three-Mode Harmonic Oscillator for Coordinate Operators Satisfying Cyclic Commutative Relations Obtained by IEO Method

    Science.gov (United States)

    Wu, Hao; Fan, Hong-Yi

    2008-12-01

    Eigenvalue-solution to those Hamiltonians involving non-commutative coordinates is not easily obtained. In this paper we apply the invariant eigen-operator (IEO) method to solving the energy spectrum of the three-mode harmonic oscillator in non-commutative space with the coordinate operators satisfying cyclic commutative relations, [X1,X2] = [X2,X3] = [X3,X1] = iθ, and this method seems effective and concise.

  5. Effects of sulfur-metabolizing bacterial community diversity on H2S emission behavior in landfills with different operation modes.

    Science.gov (United States)

    Fang, Yuan; Du, Yao; Hu, Lifang; Xu, Jing; Long, Yuyang; Shen, Dongsheng

    2016-11-01

    Hydrogen sulfide (H 2 S) is one of the major contributors to offensive odors from landfills, and its concentration differs under different operation modes. This study examined the distribution of H 2 S emission from different landfill depths under different operation modes (anaerobic, semi-aerobic, semi-aerobic transformation, and the three operation modes with additional leachate recirculation). The microbial community (especially the sulfur-metabolizing bacterial community) was investigated using high-throughput sequencing technology. The results showed that the semi-aerobic mode could substantially lower the risks of H 2 S pollution in landfills, which might be because of the difference in biological processes related to sulfur metabolism driven by functional microbes. A myriad of factors are responsible for mutually shaping the sulfur-metabolizing bacterial community composition in landfills that might subsequently affect the behavior of H 2 S emission in landfills. The differences in abundance of the genera Acinetobacter and Paracoccus (phylum Proteobacteria) caused by environmental factors might explain the differences in H 2 S emission. H 2 S odor control could be realized if the related functional microbe diversity can be influenced by adjustments to landfill operation.

  6. 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…

  7. 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 ...

  8. Multiple dual mode counter-current chromatography with periodic sample injection: Steady-state and non-steady-state operation.

    Science.gov (United States)

    Kostanyan, Artak E

    2014-12-19

    The multiple dual mode (MDM) counter-current chromatography (CCC) separation consists of a succession of two isocratic counter-current steps and is carried out in series alternating between normal phase and reversed phase operation. The performance of the MDM technique can be improved by the sample re-injection between each of the dual-mode steps. The objective of this work was to develop analytical expressions to describe the MDM CCC with periodic sample injection, which can be used to simulate these processes and select optimal operating conditions for the separation of a given feed mixture. Two possible methods of the MDM separation with periodic sample injection are considered: 1 - steady-state separation: the duration of the flow periods of the phases is kept constant for all the cycles and the steady-state regime is achieved after a certain number of cycles. 2 - non-steady-state separation with variable duration of phase elution steps. It is shown that proper selection of the duration of phase flow times allows to reach complete separation of solutes in continuous steady-state operation mode even in a low efficiency column. This mode of operation provides both high productivity and high resolution. The non-steady-state method with variable duration of phase elution steps offers several options to split a mixture into groups of compounds and/or concentrate target compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. 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.

  10. Persistent Operational Synchrony within Brain Default-Mode Network and Self-Processing Operations in Healthy Subjects

    Science.gov (United States)

    Fingelkurts, Andrew A.; Fingelkurts, Alexander A.

    2011-01-01

    Based on the theoretical analysis of self-consciousness concepts, we hypothesized that the spatio-temporal pattern of functional connectivity within the default-mode network (DMN) should persist unchanged across a variety of different cognitive tasks or acts, thus being task-unrelated. This supposition is in contrast with current understanding…

  11. Cosmetics Europe Guidelines on the Management of Undesirable Effects and Reporting of Serious Undesirable Effects from Cosmetics in the European Union

    Directory of Open Access Journals (Sweden)

    Gerald Renner

    2017-01-01

    Full Text Available The European Union (EU Cosmetics Regulation (EC No. 1223/2009 requires companies to collect and assess reports of adverse health effects from the cosmetic products (undesirable effects they market. Furthermore, undesirable effects that are considered as serious need to be reported to the national competent authorities. Cosmetics Europe, representing the European cosmetics industry, has developed these guidelines to promote a consistent practical approach for the management of undesirable effects and the notification of serious undesirable effects. Following these guidelines allows companies concerned to demonstrate due diligence and compliance with the legal requirements.

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

    DEFF Research Database (Denmark)

    Bruun, Erik

    distortion expected from devices with a statistical mismatch and it is concluded that harmonic distortion levels somewhat below 1% are attainable.Altogether, in the dissertation the current mode technique is demonstrated as an interesting and relevant technique for processing of analog signals. A good reason...... AB conveyor implementations to implementations based on purely digital circuit structures and on more complex analog subsystems such as a voltage mode opamp with feedback to provide a voltage follower action. An important by-product of the investigation of current mode structures is the definition...

  13. 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.

  14. 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.

  15. 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...

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

    International Nuclear Information System (INIS)

    Li, W.X.; Song, Y.T.; Ye, M.Y.; Peng, X.B.; Wu, S.T.; Qian, X.Y.; Zhu, C.C.

    2016-01-01

    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.

  17. Process model comparison and transferability across bioreactor scales and modes of operation for a mammalian cell bioprocess.

    Science.gov (United States)

    Craven, Stephen; Shirsat, Nishikant; Whelan, Jessica; Glennon, Brian

    2013-01-01

    A Monod kinetic model, logistic equation model, and statistical regression model were developed for a Chinese hamster ovary cell bioprocess operated under three different modes of operation (batch, bolus fed-batch, and continuous fed-batch) and grown on two different bioreactor scales (3 L bench-top and 15 L pilot-scale). The Monod kinetic model was developed for all modes of operation under study and predicted cell density, glucose glutamine, lactate, and ammonia concentrations well for the bioprocess. However, it was computationally demanding due to the large number of parameters necessary to produce a good model fit. The transferability of the Monod kinetic model structure and parameter set across bioreactor scales and modes of operation was investigated and a parameter sensitivity analysis performed. The experimentally determined parameters had the greatest influence on model performance. They changed with scale and mode of operation, but were easily calculated. The remaining parameters, which were fitted using a differential evolutionary algorithm, were not as crucial. Logistic equation and statistical regression models were investigated as alternatives to the Monod kinetic model. They were less computationally intensive to develop due to the absence of a large parameter set. However, modeling of the nutrient and metabolite concentrations proved to be troublesome due to the logistic equation model structure and the inability of both models to incorporate a feed. The complexity, computational load, and effort required for model development has to be balanced with the necessary level of model sophistication when choosing which model type to develop for a particular application. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  18. Environmentally Clean Mitigation of Undesirable Plant Life Using Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; McGrann, T J; Yamamoto, R M; Parker, J M

    2009-07-01

    This concept comprises a method for environmentally clean destruction of undesirable plant life using visible or infrared radiation. We believe that during the blossom stage, plant life is very sensitive to electromagnetic radiation, with an enhanced sensitivity to specific spectral ranges. Small doses of irradiation can arrest further plant growth, cause flower destruction or promote plant death. Surrounding plants, which are not in the blossoming stage, should not be affected. Our proposed mechanism to initiate this effect is radiation produced by a laser. Tender parts of the blossom possess enhanced absorptivity in some spectral ranges. This absorption can increase the local tissue temperature by several degrees, which is sufficient to induce bio-tissue damage. In some instances, the radiation may actually stimulate plant growth, as an alternative for use in increased crop production. This would be dependent on factors such as plant type, the wavelength of the laser radiation being used and the amount of the radiation dose. Practical, economically viable realization of this concept is possible today with the advent of high efficiency, compact and powerful laser diodes. The laser diodes provide an efficient, environmentally clean source of radiation at a variety of power levels and radiation wavelengths. Figure 1 shows the overall concept, with the laser diodes mounted on a movable platform, traversing and directing the laser radiation over a field of opium poppies.

  19. Preventing Undesirable Seismic Behaviour of Infill Walls in Design Process

    Directory of Open Access Journals (Sweden)

    Azadeh Noorifard

    2017-03-01

    Full Text Available Dividing walls are usually considered as non-structural elements, but experiences of past earthquakes show that some buildings designed and constructed by engineers have been damaged during earthquakes because of disregarding the negative effects of walls. Apart from the poor quality of construction and materials, inattention in design process is the main reason for undesirable seismic behaviour of walls.The main aim of this paper is to investigate the measures taken in different stages of architectural and structural design for improving the seismic behaviour of infilled concrete structures. As a general principle, with the further progress of project from basic architectural design to detailed structural design, there is a need to reduce designer authority and increase obligation, furthermore the cost of project increases too. The conclusion of this study implies that, in order to achieve the desirable seismic behaviour of walls, close collaboration between architects and structural engineers is required from the early stages of design. The results of this study are presented in a check list for designing reinforced concrete (RC moment resisting frame and RC shear wall.

  20. 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)

  1. 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.

  2. 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.

  3. 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

    2018-02-02

    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 Al 2 O 3 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.

  4. 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.

  5. The analysis of an operating mode of the asynchronous generator with capacitor excitation

    Directory of Open Access Journals (Sweden)

    Postoronca S.

    2008-08-01

    Full Text Available On the basis of a symbolical method of calculation of electric circuits the analysis of features of work of the three-phase asynchronous generator with two windings on статоре and capacitor excitation is executed. Results of the analysis of influence on a phase corner of a current and voltage of a windings of excitation of the generator are submitted at change of its loading from a mode of idling up to a mode of short circuit. Recommendations on stabilization of a target voltage of the generator are formulated at change of its loading.

  6. The asymmetry of electrical processes in modular strukture pulse converters of constant voltage with limit – discontinuous mode of operation

    Directory of Open Access Journals (Sweden)

    Kadatskyy A.F.

    2008-06-01

    Full Text Available The features of the asymmetric electrical processes in pulse converters of constant voltage of modular structure with autotransformer connection of an among choke with limit – discontinuous mode of operation are surveyed. The ratios generalized for eight types of the powered channels are got for the calculation of currents in the elements of the schemes at no identity of electrical parameters of their among inductors.

  7. 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

  8. Improvement of the Reliability Graph with General Gates to Analyze the Reliability of Dynamic Systems That Have Various Operation Modes

    Directory of Open Access Journals (Sweden)

    Seung Ki Shin

    2016-04-01

    Full Text Available 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. Discovery of multiple, ionization-created CS{sub 2} anions and a new mode of operation for drift chambers

    Energy Technology Data Exchange (ETDEWEB)

    Snowden-Ifft, Daniel P. [Department of Physics, Occidental College, Los Angeles, California 90041 (United States)

    2014-01-15

    This paper focuses on the surprising discovery of multiple species of ionization-created CS{sub 2} anions in gas mixtures containing electronegative CS{sub 2} and O{sub 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.

  10. 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

  11. 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.

  12. Some Operational Characteristics of Glycine Release in Rat Retina: The Role of Reverse Mode Operation of Glycine Transporter Type-1 (GlyT-1) in Ischemic Conditions.

    Science.gov (United States)

    Hanuska, Adrienn; Szénási, Gábor; Albert, Mihaly; Koles, Laszlo; Varga, Agoston; Szabo, Andras; Matyus, Peter; Harsing, Laszlo G

    2016-02-01

    Rat posterior eyecups containing the retina were prepared, loaded with [(3)H]glycine and superfused in order to determine its release originated from glycinergic amacrine cells and/or glial cells. Deprivation of oxygen and glucose from the Krebs-bicarbonate buffer used for superfusion evoked a marked increase of [(3)H]glycine release, an effect that was found to be external Ca(2+)-independent. Whereas oxygen and glucose deprivation increased [(3)H]glycine release, its uptake was reduced suggesting that energy deficiency shifts glycine transporter type-1 operation from normal to reverse mode. The increased release of [(3)H]glycine evoked by oxygen and glucose deprivation was suspended by addition of the non-competitive glycine transporter type-1 inhibitor NFPS and the competitive inhibitor ACPPB further suggesting the involvement of this transporter in the mediation of [(3)H]glycine release. Oxygen and glucose deprivation also evoked [(3)H]glutamate release from rat retina and the concomitantly occurring release of the NMDA receptor agonist glutamate and the coagonist glycine makes NMDA receptor pathological overstimulation possible in hypoxic conditions. [(3)H]Glutamate release was suspended by addition of the excitatory amino acid transporter inhibitor TBOA. Sarcosine, a substrate inhibitor of glycine transporter type-1, also increased [(3)H]glycine release probably by heteroexchange shifting transporter operation into reverse mode. This effect of sarcosine was also external Ca(2+)-independent and could be suspended by NFPS. Energy deficiency in retina induced by ouabain, an inhibitor of the Na(+)-K(+)-dependent ATPase, and by rotenone, a mitochondrial complex I inhibitor added with the glycolytic inhibitor 2-deoxy-D-glucose, led to increase of retinal [(3)H]glycine efflux. These effects of ouabain and rotenone/2-deoxy-D-glucose could also be blocked by NFPS pointed to the preferential reverse mode operation of glycine transporter type-1 as a consequence of

  13. 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

  14. 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

  15. Matching of the coupler cavity to travelling wave structures at any operating mode

    International Nuclear Information System (INIS)

    Chanudet, M.

    1993-06-01

    For the realization of an accelerating travelling wave structure, it is important to adjust the coupler so that the rf power arriving through a rectangular waveguide is coupled to the structure without reflection from the input aperture of the first cavity, the coupler cavity. The problem consists in carefully determining the dimensions of the coupling aperture. A method is proposed to measure this coupling in the case of monoperiodic forward and backward wave structures. The theory is based on the possibility of representing the properties of electromagnetic modes in periodic structures by coupled RLC circuits. The study of current I and voltage V versus frequency ω allows the simulation of H and E fields, respectively, for the different modes appearing in a travelling wave structure. (K.A.) 4 refs.; 14 figs

  16. MEDICAL OPERATIONS IN DENIED ENVIRONMENTS (MODE): ARE OUR AF MEDICS READY

    Science.gov (United States)

    2016-02-28

    The ASB solution to A2 /AD challenges in the global commons “is to develop networked , integrated forces capable” of far-reaching strike abilities to...mitigate the unique requirements of an A2 /AD scenario. A fundamental component for reducing mortality in MODE is the development of networked and...much attention in recent years is the development of anti-access/area denial ( A2 /AD) capabilities by international actors. In the 2015 National

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. Two-Switch Voltage Equalizer Using a Series-Resonant Voltage Multiplier Operating in Frequency-Multiplied Discontinuous Conduction Mode for Series-Connected Supercapacitors

    OpenAIRE

    Uno, Masatoshi; Kukita, Akio

    2015-01-01

    Cell voltage equalizers are necessary to ensure years of operation and maximize the chargeable/dischargeable energy of series-connected supercapacitors (SCs). A two-switch voltage equalizer using a series-resonant voltage multiplier operating in frequency-multiplied discontinuous conduction mode (DCM) is proposed for series-connected SCs in this paper. The frequency-multiplied mode virtually increases the operation frequency and hence mitigates the negative impact of the impedance mismatch of...

  3. 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

  4. Load Sharing Using Droop Control for Parallel Operation of Matrix Converters as Distributed Generator Interfaces in Isolated Mode

    DEFF Research Database (Denmark)

    Liu, Xiong; Loh, Poh Chiang; Blaabjerg, Frede

    2012-01-01

    DGs to share common loads in isolated operation mode. Through the adjustment of load side frequency and voltage amplitude using the droop characteristic of P/ω and Q/V, the load side active/reactive powers can be shared properly among the DGs. Load side voltages and generator side currents should......Matrix converter (MC) can be used as ac type distributed generator (DG) interface in microgrid. Reverse power flow operation of MC can be implemented to meet voltage boost requirement, where the input ac generator is connected to the converter's voltage source side and the output utility grid...... or load is connected to the current source side. During grid fault or intentional islanded operation, the DGs need to supply local loads with high quality voltage and share the loads proportionally to their power ratings. This paper proposes droop control strategy for two parallel MCs with two separate...

  5. Single-longitudinal-mode Er:GGG microchip laser operating at 2.7  μm.

    Science.gov (United States)

    You, Zhenyu; Wang, Yan; Xu, Jinlong; Zhu, Zhaojie; Li, Jianfu; Wang, Hongyan; Tu, Chaoyang

    2015-08-15

    We reported on a diode-end-pumped single-longitudinal-mode microchip laser using a 600-μm-thick Er:GGG crystal at ∼2.7  μm, generating a maximum output power of 50.8 mW and the maximum pulsed energy of 0.306 mJ, with repetition rates of pumping light of 300, 200, and 100 Hz, respectively. The maximum slope efficiency of the laser was 20.1%. The laser was operated in a single-longitudinal mode centered at about 2704 nm with a FWHM of 0.42 nm. The laser had a fundamental beam profile and the beam quality parameter M(2) was measured as 1.46. These results indicate that the Er:GGG microchip laser is a potential compact mid-infrared laser source.

  6. Study on characteristics of eddy current array coil operated in transmit-receive mode and surface inspection using this probe

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hun; Jee, Dong Hyun; Cho, Chan Hee; Kim, In Chul [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    Eddy current array (ECA) technology provides the ability to electronically scan without mechanical scanning for a footprint of probe that consists of several eddy current coils arranged side-by-side and two dimensionally. Compared to single-coil eddy current technology, the ECA technology has a higher inspection speed and reliability because a large area can be covered in a single-probe pass and the obtained images can facilitate data interpretation. In this study, we developed an eddy current array probe with 2×16 coil arrays and a multiplexer that can select transmit-receive coils sequentially and operate in transmit-receive mode. Surface inspection was performed using this probe for specimens that had various flaws and the characteristics of transmit-receive mode ECA technology was studied through an analysis of the obtained eddy current signals and C-scan images.

  7. 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

  8. 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 ...

  9. 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)

  10. 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.

  11. 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

  12. A Review on Pacemakers: Device Types, Operating Modes and Pacing Pulses. Problems Related to the Pacing Pulses Detection

    Directory of Open Access Journals (Sweden)

    Valentin Tsibulko

    2014-06-01

    Full Text Available A pacemaker is a small battery-operated medical device that delivers electrical impulses to the heart in order to guarantee regular contractions. Depending on the number of active leads the pacemakers are single chamber, dual chamber and bi-ventricular. According to their programming the devices could be with fixed-rate, 'on demand' and rate-responsitive. The operating mode of the pacemaker depends on the paced chamber, the sensed chamber, the response to a sensed electrical signal and the rate modulation. Two types of pacing are recognized - unipolar and bipolar, represented with different pacing artifacts in the ECG signal. The pacing pulse on the skin surface usually have very fast rising edges of the order of 10 µs or less and could be as small as few hundreds µV. The pacing artifacts detection is important since they indicate the presence of a pacemaker and help to evaluate the reaction of the heart. All pertinent medical standards require the pacing artifacts to be captured and indicated on the screen of the device. This paper presents a short review on pacemakers - reasons for implementation, device types, different operation modes and pacing pulses. It reveals some common problems with the detection of pacemaker's artifacts.

  13. The effect of different operations modes on science capabilities during the 2010 Desert RATS test: Insights from the geologist crewmembers

    Science.gov (United States)

    Bleacher, Jacob E.; Hurtado, José M.; Young, Kelsey E.; Rice, James W.; Garry, W. Brent

    2013-10-01

    The 2010 Desert RATS field test utilized two Space Exploration Vehicles (prototype planetary rovers) and four crewmembers (2 per rover) to conduct a geologic traverse across northern Arizona while testing continuous and twice-per-day communications paired with operation modes of separating and exploring individually (Divide & Conquer) and exploring together (Lead & Follow), respectively. This report provides qualitative conclusions from the geologist crewmembers involved in this test as to how these modes of communications and operations affected our ability to conduct field geology. Each mode of communication and operation provided beneficial capabilities that might be further explored for future Human Spaceflight Missions to other solar system objects. We find that more frequent interactions between crews and an Apollo-style Science Team on the Earth best enables scientific progress during human exploration. However, during multiple vehicle missions, this communication with an Earth-based team of scientists, who represent "more minds on the problem", should not come at the exclusion of (or significantly decrease) communication between the crewmembers in different vehicles who have the "eyes on the ground". Inter-crew communications improved when discussions with a backroom were infrequent. Both aspects are critical and cannot be mutually exclusive. Increased vehicle separation distances best enable encounters with multiple geologic units. However, seemingly redundant visits by multiple vehicles to the same feature can be utilized to provide improved process-related observations about the development and modification of the local terrain. We consider the value of data management, transfer, and accessibility to be the most important lesson learned. Crews and backrooms should have access to all data and related interpretations within the mission in as close to real-time conditions as possible. This ensures that while on another planetary surface, crewmembers are as

  14. Studying the operation of a VVER steam generator in the condensing mode at different parameters of emergency processes

    Science.gov (United States)

    Morozov, A. V.; Shlepkin, A. S.; Kalyakin, D. S.; Soshkina, A. S.

    2017-05-01

    The article presents the results of the experimental study of heat and mass transfer processes in an NPP steam generator during the operation of passive safety systems of new-generation VVER reactor installations. At the GE2M-PG test rig in the Leypunsky Institute for Physics and Power Engineering, two series of experiments corresponding to different stages of the accident were completed. In these experiments, the performance of VVER steam generator in the condensing mode with and without the removal of gas-vapor mixture from the "cold" header has been studied. As a result of the first series of experiments, it was found that, for any of the parameters of the emergency process, the steam generator's power does not drop below 80% of the original value. Furthermore, we revealed that the composition and physical properties of gases in the investigated concentration range did not notably affect the processes in the steam generator. In the second series of experiments without removal of noncondensable gases, the influence of parameters of the emergency process on the efficiency of heat transfer in the steam generator operating in the condensing mode was investigated. In order to study the heat transfer processes, we studied the change of the temperature difference between the media of the first and second circuits in our experiments. We found that the value of the temperature difference depends on both the mass of noncondensable gases accumulated in the tube bundle and their accumulation rate. The accumulation rate is determined by the power of the steam generator and the concentration of gases entering the steam generator. As a result of the analysis of experimental data, we obtained the analytical dependence reflecting change in the power of the steam generator operating in the emergency condensing mode.

  15. 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

    . At the same time, the target of a long service time (25 years or more) imposes new challenges to grid-connected transformer-less PV systems. Achieving more reliable PV inverters is of intense interest in recent research. As one of the most critical stresses that induce failures, the thermal stresses...... on the power devices of a single-phase full-bridge PV inverter are analyzed in different operational modes in this paper. The low voltage grid condition is specially taken into account in this paper. The analysis is demonstrated by a 3 kW single-phase full-bridge grid-connected PV system by simulations...

  16. 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.

  17. 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...... hands. The random capacities of the channels are evaluated in terms of outage capacity. For an SNR of 10 dB, median capacities in free space of about 4.4–4.7 bit/s/Hz for the low band and about 3.3–3.8 bit/s/Hz for the high band were found. The mean decrease in outage capacity due to the user was found...

  18. 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.

  19. 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)

  20. 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.

  1. 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.; Pratt, W.T. [Brookhaven National Lab., Upton, NY (United States); Robinson, R.C. Jr.

    1994-10-01

    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 (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected for study. The program consisted of two parallel projects performed by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf).

  2. 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

  3. Adjustment and research on the nozzle governing ultra-supercritical unit’s operation mode

    Science.gov (United States)

    Wan, Zhong-hai; Yan, Tao; Lu, Jin; Chen, Wen; Cai, Wen

    2017-11-01

    The mixed-valve sequence of an ultra-supercritical steam turbine designed by the manufacturer is only applicable to basic load. The best initial steam pressure corresponding to the different load under the sequence-valve sequence is determined by field optimization test, which can improve the operating economy and the frequency-modulation response capability under partial load.

  4. 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

  5. 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

  6. 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.

  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.; 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.

  8. Analysis and Assessments of Combined Cooling, Heating and Power Systems in Various Operation Modes for a Building in China, Dalian

    Directory of Open Access Journals (Sweden)

    Huanan Li

    2013-05-01

    Full Text Available Combined Cooling, Heating and Power (CCHP systems have been widely used in different kinds of buildings to make better use of fuels because of their high overall efficiency. This paper presents a mathematical analysis of a CCHP system in comparison to a Heating, Ventilation and Air Conditioning (HVAC system. The operation strategies following electric load (FEL, thermal load (FTL and a hybrid electric-thermal load (FHL are proposed and investigated in this study. Criteria, namely primary energy saving (PES, exergy efficiency (ηexergy, and CO2 emission reduction (CER are defined to evaluate the performances of CCHP systems for a hypothetical building located in Dalian (China. The results indicate that: (1 a new mathematical foundation is established to find whether the recovered thermal energy and the amount of electricity generated by the power generation unit (PGU are enough to provide the energy required; (2 the CCHP system does not always perform better than a HVAC system from an instantaneous perspective, especially in FTL mode; (3 the CCHP system in FEL operation mode can be seen as a suitable energy system in Dalian from the annual performance perspective. Furthermore, a sensitivity analysis is presented in order to show how the performances vary due to the changes of various technical variables.

  9. 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.

  10. FEA modeling of CMUT with membrane stand-off structures to enable selectable frequency-mode operation.

    Science.gov (United States)

    Eames, Matthew D C; Reck, Theodore J; Kilroy, Joseph P; Hossack, John A

    2011-12-01

    A selectable, dual-frequency, capacitive micro- machined ultrasonic transducer (CMUT) designed for both high-frequency imaging and low-frequency therapeutic effect is presented. A validated finite element analysis (FEA) CMUT model was used to examine the performance of the proposed dual-frequency transducer. CMUT device simulations were used to design a hybrid device incorporating stand-off structures that divide a large, low-frequency membrane into smaller, high-frequency sub-membranes when the membrane is partially collapsed so that the stand-offs contact the substrate. In low-frequency operation, simulations indicated that the peak negative pressure achieved by the hybrid device, when biased by 30.0 VDC and excited by a 2-MHz signal with 30.0 V amplitude, exceeded 190 kPa, which is sufficient for microbubble rupture. Low-frequency mode bandwidth was 93% at a center frequency of 2.1 MHz. In the high-frequency mode of operation, the device was excited by 175 Vdc and 87.5 Vac, which generated a peak negative pressure of 247 kPa. Device center frequency was 44.1 MHz with a - 6-dB fractional bandwidth of 42%.

  11. Modeling and analysis of dual-output piezoelectric transformer operating at the thickness-shear vibration mode.

    Science.gov (United States)

    Du, Jinlong; Hu, Junhui; Tseng, King-Jet; Kai, Chen Shu; Siong, Goh Chee

    2006-03-01

    In our previous study, the multioutput piezoelectric transformer operating at the thickness-shear vibration mode was proposed and experimentally investigated. By designing a new construction of support and lead wire connection, a power density of 52.7 W/cm3 and a total output power of 169.8 W were achieved at a temperature rise less than 20 degrees C. In this work, a theoretical model was developed for the dual-output piezoelectric transformer operating at the thickness-shear vibration mode. The equivalent circuit parameters of the piezoelectric transformer were derived. Based on this, the impedance characteristics, equivalent inductance, capacitance ratio, voltage gain, and efficiency of the piezoelectric transformer were calculated. The theoretical results were verified by experimental data. Furthermore, the effect of the transformer size on the voltage gain, efficiency, output power and power density, and the effect of the load of one output on the voltage gain of another output were analyzed. Some useful guidelines were achieved by these analyses.

  12. 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.

  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. 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 ...

  15. Concept and realization of unmanned aerial system with different modes of operation

    Science.gov (United States)

    Czyba, Roman; Szafrański, Grzegorz; Janusz, Wojciech; Niezabitowski, Michał; Czornik, Adam; Błachuta, Marian

    2014-12-01

    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.

  16. 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.

  17. 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.

  18. Theoretical and experimental investigations on powerful gyrotrons operating in asymmetrical high order modes

    International Nuclear Information System (INIS)

    Gantenbein, G.

    1993-09-01

    The application of high power mm-waves in nuclear fusion makes great demands on RF generators. Presently, high power (∝1 MW) per unit at frequencies around 140 GHz is required for economically reasonable and physically realizable heating and control of the stability of fusion plasmas. Owing to their advanced stage of development gyrotrons are the most promising devices to fulfill the various requirements. In this work the numerical and experimental optimisation of high power gyrotrons will be discussed. The experimental set-up and the theoretical model to describe the behaviour of gyrotron cavities will be presented. Experimental results and numerical simulations will be compared for the case of a TE 10,4 mode gyrotron. Particular attention is paid on the influence of non-optimal electron beam parameters and on reflections of RF oscillations in the cavity. Results of numerical investigations will be presented for cavities which are capable of generating RF powers around 1 MW. Some common problems and possible solutions will be described. (orig./HP) [de

  19. 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.

  20. Operating modes of a hydrogen ion source based on a hollow-cathode pulsed Penning discharge.

    Science.gov (United States)

    Oks, E M; Shandrikov, M V; Vizir, A V

    2016-02-01

    An ion source based on a hollow-cathode Penning discharge was switched to a high-current pulsed mode (tens of amperes and tens of microseconds) to produce an intense hydrogen ion beam. With molecular hydrogen (H2), the ion beam contained three species: H(+), H2(+), and H3(+). For all experimental conditions, the fraction of H2 (+) ions in the beam was about 10 ÷ 15% of the total ion beam current and varied little with ion source parameters. At the same time, the ratio of H(+) and H3(+) depended strongly on the discharge current, particularly on its distribution in the gap between the hollow and planar cathodes. Increasing the discharge current increased the H(+) fraction in ion beam. The maximum fraction of H(+) reached 80% of the total ion beam current. Forced redistribution of the discharge current in the cathode gap for increasing the hollow cathode current could greatly increase the H3(+) fraction in the beam. At optimum parameters, the fraction of H3(+) ions reached 60% of the total ion beam current.

  1. 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

  2. Teaches’ Reactions towards Undesirable Behaviors of Administrators: Whistle-blowing or Keeping Silent?

    Directory of Open Access Journals (Sweden)

    Asiye TOKER GÖKÇE

    2015-11-01

    Full Text Available This research aims to define teachers’ attitudes towards undesired behaviours at school. Therefore, in which possible undesired administrative behaviours teachers would blow a whistle was examined. Second, whether the teachers would prefer whistle-blowing or and the kind of blowing was questioned. Lastly, the reason of keeping silence was examined. This research was designed as qualitative model. The research group was 20 teachers that work at a secondary school in Darica district of Kocaeli. The results revealed that it was put forward that all teachers would react in the case of various undesired behaviours. However it was determined that teachers would mostly react in the case of serious undesired behaviours. Teachers mostly stated that they would prefer to whistle-blow internally, formally and by identifying themselves. Findings of the research are thought to contribute to the literature in terms of revealing teachers’ attitudes towards possible undesired behaviours at school.

  3. 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.

  4. 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

  5. Impact of MSWI Bottom Ash Codisposed with MSW on Landfill Stabilization with Different Operational Modes

    Directory of Open Access Journals (Sweden)

    Wen-Bing Li

    2014-01-01

    Full Text Available The aim of the study was to investigate the impact of municipal solid waste incinerator (MSWI bottom ash (BA codisposed with municipal solid waste (MSW on landfill stabilization according to the leachate quality in terms of organic matter and nitrogen contents. Six simulated landfills, that is, three conventional and three recirculated, were employed with different ratios of MSWI BA to MSW. The results depicted that, after 275-day operation, the ratio of MSWI BA to fresh refuse of 1 : 10 (V : V in the landfill was still not enough to provide sufficient acid-neutralizing capacity for a high organic matter composition of MSW over 45.5% (w/w, while the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V could act on it. Among the six experimental landfills, leachate quality only was improved in the landfill operated with the BA addition (the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V and leachate recirculation.

  6. Impact of MSWI Bottom Ash Codisposed with MSW on Landfill Stabilization with Different Operational Modes

    Science.gov (United States)

    Li, Wen-Bing; Yao, Jun; Zhou, Gen-Di; Dong, Ming; Shen, Dong-Sheng

    2014-01-01

    The aim of the study was to investigate the impact of municipal solid waste incinerator (MSWI) bottom ash (BA) codisposed with municipal solid waste (MSW) on landfill stabilization according to the leachate quality in terms of organic matter and nitrogen contents. Six simulated landfills, that is, three conventional and three recirculated, were employed with different ratios of MSWI BA to MSW. The results depicted that, after 275-day operation, the ratio of MSWI BA to fresh refuse of 1 : 10 (V : V) in the landfill was still not enough to provide sufficient acid-neutralizing capacity for a high organic matter composition of MSW over 45.5% (w/w), while the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V) could act on it. Among the six experimental landfills, leachate quality only was improved in the landfill operated with the BA addition (the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V)) and leachate recirculation. PMID:24779006

  7. 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

  8. 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)

  9. 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...

  10. In vitro propagation of plant virus using different forms of plant tissue culture and modes of culture operation.

    Science.gov (United States)

    Shih, Sharon M-H; Doran, Pauline M

    2009-09-10

    Plant virus accumulation was investigated in vitro using three different forms of plant tissue culture. Suspended cells, hairy roots and shooty teratomas of Nicotiana benthamiana were infected with tobacco mosaic virus (TMV) using the same initial virus:biomass ratio. Viral infection did not affect tissue growth or morphology in any of the three culture systems. Average maximum virus concentrations in hairy roots and shooty teratomas were similar and about an order of magnitude higher than in suspended cells. Hairy roots were considered the preferred host because of their morphological stability in liquid medium and relative ease of culture. The average maximum virus concentration in the hairy roots was 0.82+/-0.14 mg g(-1) dry weight; viral coat protein represented a maximum of approximately 6% of total soluble protein in the biomass. Virus accumulation in hairy roots was investigated further using different modes of semi-continuous culture operation aimed at prolonging the root growth phase and providing nutrient supplementation; however, virus concentrations in the roots were not enhanced compared with simple batch culture. The relative infectivity of virus in the biomass declined by 80-90% during all the cultures tested, irrespective of the form of plant tissue used or mode of culture operation. Hairy root cultures inoculated with a transgenic TMV-based vector in batch culture accumulated green fluorescent protein (GFP); however, maximum GFP concentrations in the biomass were relatively low at 39 microg g(-1) dry weight, probably due to genetic instability of the vector. This work highlights the advantages of using hairy roots for in vitro propagation of TMV compared with shooty teratomas and suspended plant cells, and demonstrates that batch root culture is more effective than semi-continuous operations for accumulation of high virus concentrations in the biomass.

  11. Exploiting the Undesired: Beam-Gas Interactions in the LHC

    CERN Document Server

    Versaci, R; Baglin, V; Mereghetti, A

    2012-01-01

    The vacuum inside the LHC pipes has a key role in correct operation of the accelerator. The interaction of the beam with residual gas in the pipes can lead to the loss of the beam itself and damage accelerator components. Nevertheless, beam-gas interactions can be exploited to indirectly measure the gas pressure inside the beam pipe, detecting the secondaries produced. The showers generated are detected by Beam Loss Monitors, whose signals depend on the gas pressure. This technique would also allow to punctually measure the gas pressure in sections of the accelerator where vacuum gauges are not frequent, such as the arcs. The problem has been addressed by means of FLUKA simulations and the results have been benchmarked with direct measurements performed in the LHC in 2011.

  12. Multistage depressed collector with efficiency of 90 to 94 percent for operation of a dual-mode traveling wave tube in the linear region

    Science.gov (United States)

    Ramins, P.; Fox, T. A.

    1980-01-01

    An axisymmetric, multistage, depressed collector of fixed geometric design was evaluated in conjunction with an octave bandwidth, dual mode traveling wave tube (TWT). The TWT was operated over a wide range of conditions to simulate different applications. The collector performance was optimized (within the constraint of fixed geometric design) over the range of TWT operating conditions covered. For operation of the TWT in the linear, low distortion range, 90 percent and greater collector efficiencies were obtained leading to TWT overall efficiencies of 20 to 35 percent, as compared with 2 to 5 percent with an undepressed collector. With collectors of this efficiency and minimized beam interception losses, it becomes practical to design dual mode TWT's such that the low mode can represent operation well below saturation. Consequently, the required pulse up in beam current can be reduced or eliminated, and this mitigates beam control and dual mode TWT circuit design problems. For operation of the dual mode TWT at saturation, average collector efficiencies in excess of 85 percent were obtained for both the low and high modes across an octave bandwidth, leading to a three to fourfold increase in the TWT overall efficiency.

  13. 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.

  14. 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

  15. Investigations of the barbell ultrasonic transducer operated in the full-wave vibrational mode.

    Science.gov (United States)

    Fu, Zhiqiang; Xian, Xiaojun; Lin, Shuyu; Wang, Chenghui; Hu, Wenxu; Li, Guozheng

    2012-07-01

    In this paper, the resonance frequency equation and expression of displacement amplitude magnifications of a full-wave barber ultrasonic horn are obtained. By discussing the relationships between the displacement amplitude magnifications and the geometrical dimensions, the optimized design of the horn for the largest magnification is proposed, which is helpful to improve the radiation power and the transfer efficiency of the acoustic energy of the ultrasonic oscillatory system. Based on the optimized design of the horn, we introduced a barbell ultrasonic transducer operated in the longitudinal full-wave vibrational model and obtained the resonance frequency equations. For comparison, the resonance frequencies of the full-wave barbell horn and the full-wave barbell transducer are also analyzed by finite element method (FEM). It is shown that the values obtained by theoretical analysis and FEM are in good agreement with experimental observations. We hope that the research of this paper is helpful for the use of the barbell horn and transducer in the applications such as ultrasonic liquid processing. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. 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.

  17. Simulation model of a variable-speed pumped-storage power plant in unstable operating conditions in pumping mode

    Science.gov (United States)

    Martínez-Lucas, G.; Pérez-Díaz, J. I.; Sarasúa, J. I.; Cavazzini, G.; Pavesi, G.; Ardizzon, G.

    2017-04-01

    This paper presents a dynamic simulation model of a laboratory-scale pumped-storage power plant (PSPP) operating in pumping mode with variable speed. The model considers the dynamic behavior of the conduits by means of an elastic water column approach, and synthetically generates both pressure and torque pulsations that reproduce the operation of the hydraulic machine in its instability region. The pressure and torque pulsations are generated each from a different set of sinusoidal functions. These functions were calibrated from the results of a CFD model, which was in turn validated from experimental data. Simulation model results match the numerical results of the CFD model with reasonable accuracy. The pump-turbine model (the functions used to generate pressure and torque pulsations inclusive) was up-scaled by hydraulic similarity according to the design parameters of a real PSPP and included in a dynamic simulation model of the said PSPP. Preliminary conclusions on the impact of unstable operation conditions on the penstock fatigue were obtained by means of a Monte Carlo simulation-based fatigue analysis.

  18. 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.

  19. 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.

    1997-01-01

    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 DHe/χ eff ∼ 1 in all confinement regimes studied to date and there is little dependence of DHe/χ eff on the normalized gyroradius in dimensionless scaling studies, suggesting that DHe/χ eff will b ∼ 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 seed) that are difficult to extrapolate. Studies have revealed that the helium diffusivity decreases as the plasma density increases, which is unfavorable to ITER's extremely high density operation. (author). 10 refs, 3 figs

  20. 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.

  1. 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.

  2. 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.

  3. Ground tests of the Dynamic Albedo of Neutron instrument operation in the passive mode with a Martian soil model

    Science.gov (United States)

    Shvetsov, V. N.; Dubasov, P. V.; Golovin, D. V.; Kozyrev, A. S.; Krylov, A. R.; Krylov, V. A.; Litvak, M. L.; Malakhov, A. V.; Mitrofanov, I. G.; Mokrousov, M. I.; Sanin, A. B.; Timoshenko, G. N.; Vostrukhin, A. A.; Zontikov, A. O.

    2017-07-01

    The results of the Dynamic Albedo of Neutrons (DAN) instrument ground tests in the passive mode of operation are presented in comparison with the numerical calculations. These test series were conducted to support the current surface measurements of DAN onboard the MSL Curiosity rover. The instrument sensitivity to detect thin subsurface layers of water ice buried at different depths in the analog of Martian soil has been evaluated during these tests. The experiments have been done with a radioisotope Pu-Be neutron source (analog of the MMRTG neutron source onboard the Curiosity rover) and the Martian soil model assembled from silicon-rich window glass pane. Water ice layers were simulated with polyethylene sheets. All experiments have been performed at the test facility built at the Joint Institute for Nuclear Research (Dubna, Russia).

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Investigation and Classification of Short-Circuit Failure Modes Based on Three-Dimensional Safe Operating Area for High-Power IGBT Modules

    DEFF Research Database (Denmark)

    Chen, Yuxiang; Li, Wuhua; Iannuzzo, Francesco

    2018-01-01

    , in order to establish the current state of the art and trends in this area. First, the concept of 3-D safe operating area is proposed as the IGBT's operational boundary to divide the device short-circuit failure modes into short-circuit VDC/Vrated-ISC SOA limiting and short-circuit endurance time limiting...... groups. Then, the discussion is centered on currently reported IGBT short-circuit failure modes in terms of their relationships with the device 3-D short-circuit safe operating area (3D-SCSOA) characteristics. In addition, further investigation on the interaction of 3D-SCSOA characteristics...

  11. 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.

  12. Procedure for the analysis of errors of commission during non-power modes of nuclear power plant operation

    International Nuclear Information System (INIS)

    Julius, J.A.; Jorgenson, E.J.; Parry, G.W.; Mosleh, A.M.

    1996-01-01

    The continued, historical occurrence of human interactions which place nuclear power plants in a condition of potentially heightened risk is of increasing interest to regulators, utility management, and industry observers alike. These Errors of Commission (EOCs), as they are often called, lead to a variety of questions such as: 'Can the event lead to a potentially dangerous condition such as core damage? By what failure mechanisms? With what frequency? What defences does the plant have to mitigate the event? Are these actions in the Probabilistic Risk Assessment (PRA) model of the plant?'. EOCs are often excluded from the bounds of a typical PRA model, yet they have the potential for being significant contributors to risk. This paper is the second of two describing procedures for the analysis of the potential for significant errors of commission. The first paper addressed operations at power while this paper describes the procedure for non-power operations. Each procedure describes a method for identifying the opportunities for error, identifying failures modes of functions, systems, or components that could arise from such errors (referred to in this paper as error expressions), and the identification of the most significant of these EOCs based on consideration of consequences, recovery potential, and likelihood

  13. 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.

  14. 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.

  15. Semi-guiding high-aspect-ratio core (SHARC) fiber providing single-mode operation and an ultra-large core area in a compact coilable package

    Science.gov (United States)

    Rockwell, David A.; Shkunov, Vladimir V.; Marciante, John R.

    2011-07-01

    A new class of optical fiber is presented that departs from the circular-core symmetry common to conventional fibers. By using a high-aspect-ratio (~30:1) rectangular core, the mode area can be significantly expanded well beyond 10,000 μm2. Moreover, by also specifying a very small refractive-index step at the narrow core edges, the core becomes ``semi-guiding,'' i.e. it guides in the narrow dimension and is effectively un-guiding in the wide mm-scale dimension. The mode dependence of the resulting Fresnel leakage loss in the wide dimension strongly favors the fundamental mode, promoting single-mode operation. Since the modal loss ratios are independent of mode area, this core structure offers nearly unlimited scalability. The implications of using such a fiber in fiber laser and amplifier systems are also discussed.

  16. Distinct oxytocin effects on belief updating in response to desirable and undesirable feedback

    Science.gov (United States)

    Ma, Yina; Li, Shiyi; Wang, Chenbo; Liu, Yi; Li, Wenxin; Yan, Xinyuan; Chen, Qiang; Han, Shihui

    2016-01-01

    Humans update their beliefs upon feedback and, accordingly, modify their behaviors to adapt to the complex, changing social environment. However, people tend to incorporate desirable (better than expected) feedback into their beliefs but to discount undesirable (worse than expected) feedback. Such optimistic updating has evolved as an advantageous mechanism for social adaptation. Here, we examine the role of oxytocin (OT)―an evolutionary ancient neuropeptide pivotal for social adaptation―in belief updating upon desirable and undesirable feedback in three studies (n = 320). Using a double-blind, placebo-controlled between-subjects design, we show that intranasally administered OT (IN-OT) augments optimistic belief updating by facilitating updates of desirable feedback but impairing updates of undesirable feedback. The IN-OT–induced impairment in belief updating upon undesirable feedback is more salient in individuals with high, rather than with low, depression or anxiety traits. IN-OT selectively enhances learning rate (the strength of association between estimation error and subsequent update) of desirable feedback. IN-OT also increases participants’ confidence in their estimates after receiving desirable but not undesirable feedback, and the OT effect on confidence updating upon desirable feedback mediates the effect of IN-OT on optimistic belief updating. Our findings reveal distinct functional roles of OT in updating the first-order estimation and second-order confidence judgment in response to desirable and undesirable feedback, suggesting a molecular substrate for optimistic belief updating. PMID:27482087

  17. Distinct oxytocin effects on belief updating in response to desirable and undesirable feedback.

    Science.gov (United States)

    Ma, Yina; Li, Shiyi; Wang, Chenbo; Liu, Yi; Li, Wenxin; Yan, Xinyuan; Chen, Qiang; Han, Shihui

    2016-08-16

    Humans update their beliefs upon feedback and, accordingly, modify their behaviors to adapt to the complex, changing social environment. However, people tend to incorporate desirable (better than expected) feedback into their beliefs but to discount undesirable (worse than expected) feedback. Such optimistic updating has evolved as an advantageous mechanism for social adaptation. Here, we examine the role of oxytocin (OT)-an evolutionary ancient neuropeptide pivotal for social adaptation-in belief updating upon desirable and undesirable feedback in three studies (n = 320). Using a double-blind, placebo-controlled between-subjects design, we show that intranasally administered OT (IN-OT) augments optimistic belief updating by facilitating updates of desirable feedback but impairing updates of undesirable feedback. The IN-OT-induced impairment in belief updating upon undesirable feedback is more salient in individuals with high, rather than with low, depression or anxiety traits. IN-OT selectively enhances learning rate (the strength of association between estimation error and subsequent update) of desirable feedback. IN-OT also increases participants' confidence in their estimates after receiving desirable but not undesirable feedback, and the OT effect on confidence updating upon desirable feedback mediates the effect of IN-OT on optimistic belief updating. Our findings reveal distinct functional roles of OT in updating the first-order estimation and second-order confidence judgment in response to desirable and undesirable feedback, suggesting a molecular substrate for optimistic belief updating.

  18. Observation of the ballooning mode that limits the operation space of the high-density super-dense-core plasma in the LHD

    Science.gov (United States)

    Ohdachi, S.; Watanabe, K. Y.; Tanaka, K.; Suzuki, Y.; Takemura, Y.; Sakakibara, S.; Du, X. D.; Bando, T.; Narushima, Y.; Sakamoto, R.; Miyazawa, J.; Motojima, G.; Morisaki, T.; LHD Experiment Group

    2017-06-01

    The central beta of the super-dense-core (SDC) plasma in the large helical device (LHD) is limited by a large scale MHD event called ‘core density collapse’ (CDC). The detailed measurement reveals that a new type of ballooning mode, quite localized in space and destabilized from the 3D nature of Heliotron devices, is the cause of the CDC. It is the first observation of an unstable mode in a region with global negative magnetic shear. Avoidance of the excitation of this mode is a key to expand the operational limit of the LHD.

  19. A large-signal model for CMUT arrays with arbitrary membrane geometry operating in non-collapsed mode.

    Science.gov (United States)

    Satir, Sarp; Zahorian, Jaime; Degertekin, F Levent

    2013-11-01

    A large-signal, transient model has been developed to predict the output characteristics of a CMUT array operated in the non-collapse mode. The model is based on separation of the nonlinear electrostatic voltage-to-force relation and the linear acoustic array response. For modeling of linear acoustic radiation and crosstalk effects, the boundary element method is used. The stiffness matrix in the vibroacoustics calculations is obtained using static finite element analysis of a single membrane which can have arbitrary geometry and boundary conditions. A lumped modeling approach is used to reduce the order of the system for modeling the transient nonlinear electrostatic actuation. To accurately capture the dynamics of the non-uniform electrostatic force distribution over the CMUT electrode during large deflections, the membrane electrode is divided into patches shaped to match higher order membrane modes, each introducing a variable to the system model. This reduced order nonlinear lumped model is solved in the time domain using commercial software. The model has two linear blocks to calculate the displacement profile of the electrode patches and the output pressure for a given force distribution over the array. The force-to-array-displacement block uses the linear acoustic model, and the Rayleigh integral is evaluated to calculate the pressure at any field point. Using the model, the time-domain transmitted pressure can be simulated for different large drive signal configurations. The acoustic model is verified by comparison to harmonic FEA in vacuum and fluid for high- and low-aspect-ratio membranes as well as mass-loaded membranes. The overall software model is verified by comparison to transient 3-D finite element analysis and experimental results for different large drive signals, and an example for a phased array simulation is given.

  20. A Large Signal Model for CMUT Arrays with Arbitrary Membrane Geometries Operating in Non-Collapsed Mode

    Science.gov (United States)

    Satir, Sarp; Zahorian, Jaime; Degertekin, F. Levent

    2014-01-01

    A large signal, transient model has been developed to predict the output characteristics of a CMUT array operated in the non-collapse mode. The model is based on separation of the nonlinear electrostatic voltage-to-force relation and the linear acoustic array response. For linear acoustic radiation and crosstalk effects, the boundary element method is used. The stiffness matrix in the vibroacoustics calculations is obtained using static finite element analysis of a single membrane which can have arbitrary geometry and boundary conditions. A lumped modeling approach is used to reduce the order of the system for modeling the transient nonlinear electrostatic actuation. To accurately capture the dynamics of the non-uniform electrostatic force distribution over the CMUT electrode during large deflections, the membrane electrode is divided into patches shaped to match higher order membrane modes, each introducing a variable to the system model. This reduced order nonlinear lumped model is solved in the time domain using Simulink. The model has two linear blocks to calculate the displacement profile of the electrode patches and the output pressure for a given force distribution over the array, respectively. The force to array displacement block uses the linear acoustic model, and the Rayleigh integral is evaluated to calculate the pressure at any field point. Using the model, the transient transmitted pressure can be simulated for different large signal drive signal configurations. The acoustic model is verified by comparison to harmonic FEA in vacuum and fluid for high and low aspect ratio membranes as well as mass-loaded membranes. The overall Simulink model is verified by comparison to transient 3D FEA and experimental results for different large drive signals; and an example for a phased array simulation is given. PMID:24158297

  1. The effect of He-ash poisoning on L-mode and high ? operations in ITER-like plasma

    Science.gov (United States)

    Tateishi, G.; Itoh, S. I.; Yagi, M.

    1997-11-01

    The burning performance of the self-ignited steady-state plasma is investigated based on a point model. For the ITER-like parameters, the theoretical model scaling law 0741-3335/39/11/008/img7, which could explain the characteristics of the L-mode and the high 0741-3335/39/11/008/img8 fairly well, and the effect of He-ash poisoning are introduced simultaneously. The solutions are obtained by solving the particle and energy balance equations in steady-state conditions, taking account of the effect of radiation loss due to He ash and fuel ions. Typically, there exist four solutions of the plasma current at fixed temperature. The divergence of the temperature, which is predicted by a previous study (Fukuyama et al 1995 Nucl. Fusion 35 1669) for the pure plasma in the high 0741-3335/39/11/008/img8, disappears under the influence of He ash. In the low-density limit, the L-mode branches and the high 0741-3335/39/11/008/img8 branches are well separated on the plane of the current and the temperature. On the other hand, the merging of two branches occurs at higher densities due to the nonlinear effect contained in the scaling law. Examining the constraints imposed on the core plasma (the density limit, the 0741-3335/39/11/008/img11 limit and so on), we found that the self-ignited state of the high 0741-3335/39/11/008/img8 operation would be difficult.

  2. 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

  3. 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.

  4. 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...

  5. 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.

  6. Synchronized growth and neutral lipid accumulation in Chlorella sorokiniana FC6 IITG under continuous mode of operation.

    Science.gov (United States)

    Kumar, Vikram; Muthuraj, Muthusivaramapandian; Palabhanvi, Basavaraj; Das, Debasish

    2016-01-01

    Synchronized growth and neutral lipid accumulation with high lipid productivity under mixotrophic growth of the strain Chlorella sorokiniana FC6 IITG was achieved via manipulation of substrates feeding mode and supplementation of lipid elicitors in the growth medium. Screening and optimization of lipid elicitors resulted in lipid productivity of 110.59mgL(-1)day(-1) under the combined effect of lipid inducers sodium acetate and sodium chloride. Fed-batch cultivation of the strain in bioreactor with intermittent feeding of limiting nutrients and lipid inducer resulted in maximum biomass and lipid productivity of 2.08 and 0.97gL(-1)day(-1) respectively. Further, continuous production of biomass with concomitant lipid accumulation was demonstrated via continuous feeding of BG11 media supplemented with lipid inducers sodium acetate and sodium chloride. The improved biomass and lipid productivity in chemostat was found to be 2.81 and 1.27gL(-1)day(-1) respectively operated at a dilution rate of 0.54day(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Numerical Investigation of the Impact of the Compressor Operation Mode on Working Process of the Combustion Chamber

    Science.gov (United States)

    Orlov, M. Yu; Lukachev, S. V.; Anisimov, V. M.

    2018-01-01

    The method of integrated compressor/combustor simulation was used to investigate the impact of flow distortion, appeared due to compressor blades, during the combustion chamber workflow. The method was improved in terms of generating a common grid and of principles of the boundary conditions settings. The geometric model includes four geometric volume bodies: guide vanes of the penultimate stage of high-pressure compressor, the impeller and guide vanes of the last stage and the flow path of combustion chamber. The calculation was carried out for some operation mode of the engine (nominal, 0.7 of nominal and 0.5 of nominal regimes) with and without compressor. The results were compared with the results of combustion chamber simulation without the compressor. Simulations showed that blade wakes extend up to the flame tube head. These wakes influence on the flame tongue, pressure field, temperature and velocity in the recirculation-mixing zone. It can influence on combustion efficiency, ecological performance and on temperature field at the combustor outlet. Thus, the simulations, which take into account combustion chamber and compressor, are more fully represent the characteristics of the working process of the combustion chamber and increase the efficiency of the design of new products.

  8. A fast response oxygen sensor based upon a fully-sealed zirconia pump-gauge operated in the potentiometric mode

    Science.gov (United States)

    Benammar, M.; Maskell, W. C.

    1992-06-01

    An instrument for fast and continuous measurement of oxygen partial pressure not requiring a reference gas was constructed around a sealed zirconia oxygen pump-gauge sensor operated in the ac mode. By appropriate signal processing of the gauge EMF, the mean oxygen partial pressure within the sensor was determined and maintained constant via a feedback loop. Potentiometric measurement of the oxygen partial pressure in the sample gas was made relative to this controlled internal reference. The response time of the instrument for a step change in oxygen partial pressure from 1 to 10 kPa was only 65 ms. ned" OutputMedium="All"> 1 3 Proceedings of the 29th International Conference on the Applications of the Mössbauer Effect (ICAME 2007) held in Kanpur, India, 14-19 October 2007, PART IV/VII 30 2008 11 19 2008 11 18 2008 7 2008 Springer Science+Business Media B.V. 2008 9803 10.1007/s10751-008-9803-9 1 On the phenomena occurring at the interface between iron and iron–platinum thin films 1 7 2008 9 17 2008 10 10 Springer Science+Business Media B.V.

  9. New Small-ELM H-mode Regimes for Steady-state High-performance Operations in EAST

    Science.gov (United States)

    Xu, G. S.; Yang, Q. Q.; Wang, Y. F.; Yan, N.; Hu, G. H.; Lin, X.; Xu, X. Q.; Garofalo, A. M.; Maingi, R.; EAST Team

    2017-10-01

    A stationary high-confinement (H98y2 1.1) fully non-inductive H-mode regime characterized by high-frequency (2kHz) small ELMs (divertor peak heat flux 2MW/m2) at relatively low pedestal collisionality (ν*e 1) and optimized high internal inductance (li 1.1) plasma has been recently achieved with high heating power (source power 9MW) in EAST. This regime was obtained at high triangularity δ (0.55), high q95 (6) and high βp (1.6), close to the parameter space of the grassy ELM regime in JT-60U. The relatively low plasma current, high q95, βp, and therefore high bootstrap current fraction (>30%) make it a suitable regime to achieve steady-state operation with low disruptivity, good reproducibility and robustness. The access to this regime is insensitive to the change of toroidal torque or plasma density in the explored parameter range. Benefiting from the optimized high li and high βp, good core energy confinement has been achieved even at low core toroidal rotation (Vt down to 10 km/s). Good density control has been achieved at a line-averaged density up to 76% Greenwald. Impurity concentration and core radiation were maintained at an acceptably low level, suggesting that sufficient particle exhaust can be driven by the high-frequency small ELMs.

  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. 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)

  12. The Differential Mortality of Undesired Infants in Sub-Saharan Africa.

    Science.gov (United States)

    Flatø, Martin

    2018-02-01

    With high rates of infant mortality in sub-Saharan Africa, investments in infant health are subject to tough prioritizations within the household, in which maternal preferences may play a part. How these preferences will affect infant mortality as African women have ever-lower fertility is still uncertain, as increased female empowerment and increased difficulty in achieving a desired gender composition within a smaller family pull in potentially different directions. I study how being born at a parity or of a gender undesired by the mother relates to infant mortality in sub-Saharan Africa and how such differential mortality varies between women at different stages of the demographic transition. Using data from 79 Demographic and Health Surveys, I find that a child being undesired according to the mother is associated with a differential mortality that is not due to constant maternal factors, family composition, or factors that are correlated with maternal preferences and vary continuously across siblings. As a share of overall infant mortality, the excess mortality of undesired children amounts to 3.3 % of male and 4 % of female infant mortality. Undesiredness can explain a larger share of infant mortality among mothers with lower fertility desires and a larger share of female than male infant mortality for children of women who desire 1-3 children. Undesired gender composition is more important for infant mortality than undesired childbearing and may also lead couples to increase family size beyond the maternal desire, in which case infants of the surplus gender are particularly vulnerable.

  13. Desirable and undesirable future thoughts call for different scene construction processes.

    Science.gov (United States)

    de Vito, S; Neroni, M A; Gamboz, N; Della Sala, S; Brandimonte, M A

    2015-01-01

    Despite the growing interest in the ability of foreseeing (episodic future thinking), it is still unclear how healthy people construct possible future scenarios. We suggest that different future thoughts require different processes of scene construction. Thirty-five participants were asked to imagine desirable and less desirable future events. Imagining desirable events increased the ease of scene construction, the frequency of life scripts, the number of internal details, and the clarity of sensorial and spatial temporal information. The initial description of general personal knowledge lasted longer in undesirable than in desirable anticipations. Finally, participants were more prone to explicitly indicate autobiographical memory as the main source of their simulations of undesirable episodes, whereas they equally related the simulations of desirable events to autobiographical events or semantic knowledge. These findings show that desirable and undesirable scenarios call for different mechanisms of scene construction. The present study emphasizes that future thinking cannot be considered as a monolithic entity.

  14. Ranking of bank branches with undesirable and fuzzy data: A DEA-based approach

    Directory of Open Access Journals (Sweden)

    Sohrab Kordrostami

    2016-07-01

    Full Text Available Banks are one of the most important financial sectors in order to the economic development of each country. Certainly, efficiency scores and ranks of banks are significant and effective aspects towards future planning. Sometimes the performance of banks must be measured in the presence of undesirable and vague factors. For these reasons in the current paper a procedure based on data envelopment analysis (DEA is introduced for evaluating the efficiency and complete ranking of decision making units (DMUs where undesirable and fuzzy measures exist. To illustrate, in the presence of undesirable and fuzzy measures, DMUs are evaluated by using a fuzzy expected value approach and DMUs with similar efficiency scores are ranked by using constraints and the Maximal Balance Index based on the optimal shadow prices. Afterwards, the efficiency scores of 25 branches of an Iranian commercial bank are evaluated using the proposed method. Also, a complete ranking of bank branches is presented to discriminate branches.

  15. 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.

  16. Operational risk analysis with Fuzzy FMEA (Failure Mode and Effect Analysis approach (Case study: Optimus Creative Bandung

    Directory of Open Access Journals (Sweden)

    Immawan Taufiq

    2018-01-01

    Full Text Available Industrial development in Indonesia, manufacturing and services, are required to be able to manage the company very well. However, in practice, the company’s activities are always faced with risks. In general, the risk can be defined as a situation faced by a person or a company in which there is a possibility that harm. The level of risk faced losses due to highly variable depending on the cause and effect influence. To be able to manage (risk management, it can use FMEA (Failure Mode and Effect Analysis. FMEA is a method of analyzing potential failure are applied in product development, system engineering and operational management and is one of a qualitative risk assessment. Using FMEA can also note the value of the RPN (Risk Priority Number to determine improvement priorities at risk. But there are weaknesses in the use of FMEA, namely RPN calculation is only done by multiplying the severity, occurence and detection alone and irrespective of the degree of importance of each input, to the FMEA method is integrated using fuzzy logic. Fuzzy FMEA is aimed at obtaining the highest fuzzyRPN value which will be used as the focus of improvements to minimize the possibility of these risks occur back. The results were obtained 7 out of 18 types of risks that have a high priority for repairs. Risk troublesome computer (hank / die while doing photo editing scored the highest RPN 540 (scale 1-1000 and also the highest FRPN 9 (scale 1-10. There is a difference in value between RPN and FRPN. FRPN value obtained from the fuzzification, generate value by taking into account the degree of interest of any given input.

  17. 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

  18. Risk management of undesirable substances in feed following updated risk assessments

    International Nuclear Information System (INIS)

    Verstraete, Frans

    2013-01-01

    Directive 2002/32/EC of 7 May 2002 of the European Parliament and of the Council on undesirable substances in animal feed is the framework for the EU action on undesirable substances in feed. This framework Directive provides: ⁎that products intended for animal feed may enter for use in the Union from third countries, be put into circulation and/or used in the Union only if they are sound, genuine and of merchantable quality and therefore when correctly used do not represent any danger to human health, animal health or to the environment or could adversely affect livestock production. ⁎that in order to protect animal and public health and the environment, maximum levels for specific undesirable substances shall be established where necessary. ⁎for mandatory consultation of a scientific body (EFSA) for all provisions which may have an effect upon public health or animal health or on the environment. ⁎that products intended for animal feed containing levels of an undesirable substance that exceed the established maximum level may not be mixed for dilution purposes with the same, or other, products intended for animal feed and may not be used for the production of compound feed. Based on the provisions and principles laid down in this framework Directive, maximum levels for a whole range of undesirable substances have been established at EU level. During the discussions in view of the adoption of Directive 2002/32/EC, the European Commission made the commitment to review all existing provisions on undesirable substances on the basis of updated scientific risk assessments. Following requests of the European Commission, the Panel on Contaminants in the Food Chain (CONTAM) from the European Food Safety Authority (EFSA) has completed a series of 30 risk assessments undertaken over the last 5 years on undesirable substances in animal feed reviewing the possible risks for animal and human health due to the presence of these substances in animal feed. EU legislation

  19. 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

    This paper presents the development and test of a flexible control strategy for an 11-kw wind turbine with a back-to-back power converter capable of working in both stand-alone and grid-connected mode. The stand-alone control is featured with a complex output voltage controller capable of handling...... 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...

  20. 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

  1. 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)

  2. Relationships between College Students' Credit Card Debt, Undesirable Academic Behaviors and Cognitions, and Academic Performance

    Science.gov (United States)

    Hogan, Eileen A.; Bryant, Sarah K.; Overymyer-Day, Leslie E.

    2013-01-01

    The acquisition of credit card debt by college students has long been a topic of concern. This study explores relationships among debt, undesirable academic behaviors and cognitions, and academic performance, through surveys of 338 students in a public university, replicating two past measures of credit card debt and creating new measures of…

  3. A survey on the presence of undesirable botanical substances in feed in the European Union

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Vancutsem, J.; Jorgensen, J.S.

    2009-01-01

    Directive 2002/32/EC of the European Parliament and of the Council of 7 May 2002 on undesirable substances in animal feed lists a range of substances from botanical origin (weed seeds) and additionally some chemical compounds directly originating from specific weeds. In order to examine the actual

  4. Array diagnostics, spatial resolution, and filtering of undesired radiation with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, C.; Pivnenko, Sergey; Jørgensen, E.

    2013-01-01

    This paper focuses on three important features of the 3D reconstruction algorithm of DIATOOL: the identification of array elements improper functioning and failure, the obtainable spatial resolution of the reconstructed fields and currents, and the filtering of undesired radiation and scattering...

  5. 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.

  6. Towards low timing phase noise operation in fiber lasers mode locked by graphene oxide and carbon nanotubes at 1.5 µm.

    Science.gov (United States)

    Wu, Kan; Li, Xiaohui; Wang, Yonggang; Wang, Qi Jie; Shum, Perry Ping; Chen, Jianping

    2015-01-12

    We investigate the timing phase noise of fiber lasers mode locked by graphene oxide (GO) and carbon nanotubes (CNTs), respectively, integrated in a linear cavity fiber laser in the reflecting operation. Due to the shorter decay time of the GO and CNTs, weaker slow saturable absorber effects are expected and mode-locked lasers based on these two saturable absorbers exhibit low excess timing phase noise coupled from the laser intensity noise. Compared with a reference laser mode locked by semiconductor saturable absorber mirror (SESAM), GO based laser obtains a timing phase noise reduction of 7 dB at 1 kHz and a timing jitter reduction of 45% experimentally whereas CNTs based laser obtains a timing phase noise reduction of 3 dB and a timing jitter reduction of 29%. This finding suggests that saturable absorbers with short decay time have the potential for achieving mode locking operation with low timing phase noise, which is important for applications including frequency metrology, high-precision optical sampling, clock distribution and optical sensing.

  7. 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.

  8. The Thermal State Computational Research of the Low-Thrust Oxygen-Methane Gaseous-Propellant Rocket Engine in the Pulse Mode of Operation

    OpenAIRE

    O. A. Vorozheeva; D. A. Yagodnikov

    2014-01-01

    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 t...

  9. 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)

  10. Experimental investigation of undesired stable equilibria in pumpkin shape super-pressure balloon designs

    Science.gov (United States)

    Schur, W. W.

    2004-01-01

    Excess in skin material of a pneumatic envelope beyond what is required for minimum enclosure of a gas bubble is a necessary but by no means sufficient condition for the existence of multiple equilibrium configurations for that pneumatic envelope. The very design of structurally efficient super-pressure balloons of the pumpkin shape type requires such excess. Undesired stable equilibria in pumpkin shape balloons have been observed on experimental pumpkin shape balloons. These configurations contain regions with stress levels far higher than those predicted for the cyclically symmetric design configuration under maximum pressurization. Successful designs of pumpkin shape super-pressure balloons do not allow such undesired stable equilibria under full pressurization. This work documents efforts made so far and describes efforts still underway by the National Aeronautics and Space Administration's Balloon Program Office to arrive on guidance on the design of pumpkin shape super-pressure balloons that guarantee full and proper deployment.

  11. Nanoparticle Filtration Characteristics of Advanced Metal Foam Media for a Spark Ignition Direct Injection Engine in Steady Engine Operating Conditions and Vehicle Test Modes

    Directory of Open Access Journals (Sweden)

    Cha-Lee Myung

    2015-03-01

    Full Text Available In this study, the particle formation and reduction characteristics at the engine-out position, after a three-way catalyst (TWC and a metal foam gasoline particulate filter (GPF, were evaluated for a gasoline direct-injection (GDI engine under part-load operating conditions. The vehicle tests were performed under the Federal Test Procedure-75 (FTP-75 and the Highway Fuel Economy Test (HWFET modes. Particle number (PN concentrations, size distributions, and the filtering efficiency with the GPF were evaluated with a condensation particle counter (CPC and a differential mobility spectrometer (DMS500. Under steady engine operating conditions, the PN concentrations at the engine-out position were 9.7 × 105–2.5 × 106 N/cc. While, the PN concentrations after the GPF were 9.2 × 104–3.5 × 105 N/cc, and the PN was reduced by 77%–96%. The PN filtering efficiency with the GPF-GDI vehicle reached approximately 58% in the FTP-75 and 62% in the HWFET mode. The PN concentration of the GPF-GDI vehicle was significantly reduced to 3.95 × 1011 N/km for the FTP-75 and 8.86 × 1010 N/km for the HWFET mode. The amount of nucleation mode particles below 23 nm was substantially reduced with the GPF-GDI vehicle. The fuel economy, CO2, and regulated emissions of the GPF-GDI vehicle were equivalent to those of the base GDI vehicle under the vehicle certification modes.

  12. 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

  13. Assessment of undesirable dose to eye-melanoma patients after proton radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Stolarczyk, L., E-mail: liliana.stolarczyk@ifj.edu.p [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Krakow (Poland); Olko, P.; Cywicka-Jakiel, T.; Ptaszkiewicz, M.; Swakon, J.; Dulny, B.; Horwacik, T.; Obryk, B. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Krakow (Poland); Waligorski, M.P.R. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Krakow (Poland); Maria Sklodowska-Curie Memorial Institute, Centre of Oncology, Krakow Division, ul. Garncarska 11, 31-115, Krakow (Poland)

    2010-12-15

    Radiotherapy with a proton beam of initial energy 55-80 MeV is presently the clinically recommended therapy for some cases of intraocular melanoma such as large melanomas or tumours adjacent to critical organs. Evaluation and optimization of radiation doses outside the treatment volume may contribute to reducing undesirable side-effects and decreasing the risk of occurrence of secondary cancers, particularly for paediatric patients. In this work the undesired doses to organs were assessed basing on Monte Carlo calculation of secondary radiation transport and on results of measurements of neutron and {gamma}-ray doses at the proton therapy facility of the Institute of Nuclear Physics at Krakow. Dosimetry was performed using a He-3-based FHT 762 neutron monitor (Wendi II), a FH40G proportional counter (for {gamma}-rays), and MTS-7 (LiF:Mg,Ti) thermoluminescence detectors (TLDs). Organ doses were calculated in the ADAM anthropomorphic phantom using the MCNPX Monte Carlo transport code and partly verified, for {gamma}-ray doses, with TLD measurements in the RANDO Anderson anthropomorphic phantom. The effective dose due to undesired radiation, including exposure from scattered radiation during the entire process of proton radiotherapy and patient positioning using X-rays, does not exceed 1 mSv.

  14. 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.

  15. 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

    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...... to confirm the performance and feasibility of the proposed control method in DG technology. © 2015 Published by Elsevier Ltd....

  16. 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...

  17. 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

  18. Modelling and Control Strategies of Microgrid in Grid-Connected and Islanded Operation Modes - Part I: Active Power Sharing and Frequency Control

    DEFF Research Database (Denmark)

    Wang, Lu; Hu, Yanting; Chen, Zhe

    2013-01-01

    In recent years, the utilization of renewable energy resources has promoted more and more microgrid developed. The microgrid consists of distributed generations (DGs) associate with distributed energy resources (DERs), which are normally located next to the customer and provide electric power at ...... on simulation analyses with Matlab/Simulink, the results show that the presented droop control strategy has good effects in grid-connected and islanded mode, and during operation mode transitions....... at distributed voltage level. However, when a large number of DGs were connected to the AC power grid, it can cause power quality, grid security and stability issues. This paper presents an improved P-f droop control strategy using the reciprocal characteristic to improve the stability performance. Based...

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Undesirable Behaviors Elementary School Classroom Teachers Encounter in the Classroom and Their Reasons

    Directory of Open Access Journals (Sweden)

    E.G. Balcik

    2011-12-01

    Full Text Available The present study aims to determine how often elementary school teachers encounter undesirable behaviors in the classroom and what their thoughts regarding possible reasons of these behaviors are. The teachers’ opininon about the prevalence of these behaviors and their possible reasons were evaluated according to gender, marital status, level of class being taught, size of class being taught and it was tried to be determined if there were significant differences between variables. The measurement tool was applied to a total of 54 teachers at 5 schools in Gölcük district of the Kocaeli province. The data collection tool is composed of three sections. The first section is for establishing teachers’ personal information. In this study, as a data collection tool, a questionnaire was used. When preparing questions for the questionnaire, following the examination of resources available, the questionnaire prepared by Aksoy (1999 and used in the thesis study entitled “Classroom Management and Student Discipline in Elementary Schools of Ankara” and also used in the thesis study by Boyraz (2007 entitled “Discipline Problems that Candidate Teachers Servicing at Elementary Schools Encounter in the Classroom” was employed. Although the validity and reliability of the questionnaire was tested by Aksoy (1999 and Boyraz (2007, the reliability study for the questionnaire was retested and found to be 0,9. The questionnaire include 42 items. 19 of them are related to the reasons of undesirable behaviors observed in the classroom and 23 of them are related to undesirable behaviors observed in the classroom.

  4. A survey on the presence of undesirable botanical substances in feed in the European Union

    Directory of Open Access Journals (Sweden)

    van Raamsdonk LWD.

    2009-01-01

    Full Text Available Directive 2002/32/EC of the European Parliament and of the Council of 7 May 2002 on undesirable substances in animal feed lists a range of substances from botanical origin (weed seeds and additionally some chemical compounds directly originating from specific weeds. In order to examine the actual status of enforcement and of the present occurrence of these botanical substances, a survey was carried out. A questionnaire was sent to 103 laboratories, including official control labs from all member states of the European Union. The results, indicating the frequency of occurrence as far as reported, are compared to the publications of the EU Rapid Alert System for Food and Feed (RASFF. A total of 44 questionnaires was returned (42.7% from 22 member states. Ten member states predominantly from north-western Europe appeared to have an active monitoring of botanical undesirable substances. The questionnaire results did not indicate that the other member states enforce this part of Directive 2002/32/EC. Reports on the frequency of occurrence include: a few to 25-50% of the samples contain traces of ergot (8 member states, a few to 24% contain at least some traces of thorn apple (6 member states, zero to 17% contain some castor oil plant seeds (3 member states, zero to a few samples contain Crotalaria seeds (3 member states, and zero to 6% contain traces of Sareptian mustard (4 member states. One member state conducted extra surveillance since several cases of animal intoxications have been reported. In some cases a coincidence with undesirable botanical substances was found.

  5. Discovery of Stationary Operation of Quiescent H-mode Plasmas with Net-Zero NBI Torque and High Energy Confinement on DIII-D

    Science.gov (United States)

    Burrell, Keith

    2015-11-01

    Experiments this summer in DIII-D have used edge turbulence control to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no 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 outstanding tokamak performance, well above the H98 international tokamak energy confinement scaling (H98 =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 ExB 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. 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 betan =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. Stationary operation with improved pedestal conditions is highly significant for future burning plasma devices, since operation without ELMs at low rotation and good confinement is key for fusion energy production. Supported by the US DOE under DE-FC02-04ER54698.

  6. Environmental efficiency evaluation of china based on a kind of congestion and undesirable output coefficient

    Directory of Open Access Journals (Sweden)

    Song Malin

    2015-01-01

    Full Text Available The production “congestion” phenomenon is widespread in reality although few models nowadays consider its influences. In this study, production congestion is introduced into an environmental efficiency evaluation model and a new data envelopment analysis model that considers both production congestion and undesirable output is established so as to measure environmental efficiency evaluation effectively. On this basis, we divide technological change into productive technological change and energy-savings emission reduction technological change to establish their influences on the congestion phenomenon. The results show that productive technological change cannot relieve the degree of congestion while green technology change that stimulates environmental efficiency improvement can greatly alleviate situations of congestion.

  7. Distinguishing Technical Inefficiency from Desirable and Undesirable Congestion with an Application to Regional Industries in China

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2014-12-01

    Full Text Available Congestion is an important issue that requires the efficiency of decision-making units (DMUs. We first classify conventional congestion into congestion (newly defined and technical inefficiency, based on prior research and real applications. Modified definitions and mathematical expression of congestion, managerial inefficiency, and technical inefficiency are proposed to better illustrate the differences between them. Several modified models are provided to identify and recognize those types of inefficiencies and congestion. We then extend the model by considering the desirable and undesirable types of congestion simultaneously. The proposed approach is applied and verified by identifying resource congestion and environmental inefficiencies in China’s economic development.

  8. 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)

  9. 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...

  10. 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.

  11. State space analysis of boost DC/DC converter with voltage mode control

    Science.gov (United States)

    Shenoy, K. Latha; Nayak, C. Gurudas; Mandi, Rajashekar P.

    2017-07-01

    The boost converter belongs to the family of indirect energy transfer converters. The inductor stores energy during switch on and the output capacitor deliver power to the load. During switch off condition, the stored inductive energy appears in series with the input source and supply the output. The paper deals with the small signal analysis of dc-dc boost converter. It is used in modeling the closed loop converter parameters. The boost converter produces an undesirable Right-Half Plane Zero (RHPZ) in the small signal analysis due to which the implementation of voltage mode control needs attention. This requires compensating the regulator such that the crossover frequency occurs well below the frequency of the RHP zero. The paper describes modeling of voltage mode control boost converter operating in continuous conduction mode.

  12. Watt-level widely tunable single-mode emission by injection-locking of a multimode Fabry-Perot quantum cascade laser

    Science.gov (United States)

    Chevalier, Paul; Piccardo, Marco; Anand, Sajant; Mejia, Enrique A.; Wang, Yongrui; Mansuripur, Tobias S.; Xie, Feng; Lascola, Kevin; Belyanin, Alexey; Capasso, Federico

    2018-02-01

    Free-running Fabry-Perot lasers normally operate in a single-mode regime until the pumping current is increased beyond the single-mode instability threshold, above which they evolve into a multimode state. As a result of this instability, the single-mode operation of these lasers is typically constrained to few percents of their output power range, this being an undesired limitation in spectroscopy applications. In order to expand the span of single-mode operation, we use an optical injection seed generated by an external-cavity single-mode laser source to force the Fabry-Perot quantum cascade laser into a single-mode state in the high current range, where it would otherwise operate in a multimode regime. Utilizing this approach, we achieve single-mode emission at room temperature with a tuning range of 36 cm-1 and stable continuous-wave output power exceeding 1 W at 4.5 μm. Far-field measurements show that a single transverse mode is emitted up to the highest optical power, indicating that the beam properties of the seeded Fabry-Perot laser remain unchanged as compared to free-running operation.

  13. Texas Instruments' virtual phase charge-coupled device (CCD) imager operated in the frontside electron-bombarded mode

    Science.gov (United States)

    Everett, P.; Hynecek, J.; Zucchino, P.; Lowrance, J.

    1982-01-01

    The present investigation is concerned with the suitability of the virtual phase CCD imager for frontside detection of electrons up to 25 keV. The investigation has the objective to determine if the imager can be used in the frontside mode with a photocathode to detect very low light levels in astronomical applications, the ultimate goal being individual photon detection. It is found that the standard virtual phase imager will function properly over an extended period at low levels of 20 kV electron irradiation consistent with photon counting applications. The imager can detect individual primary electrons with nearly 100 percent efficiency. However, further studies are needed to determine the mechanisms for the flat band shifts so that the imager design may be modified to eliminate or at least reduce them.

  14. Brief evaluation of the radiological hazards after a nuclear accident - description and mode of operation of this calculation code Orion

    International Nuclear Information System (INIS)

    Calando, J.P.

    1991-07-01

    The ORION code is designed to determine very quickly the immediate consequences (such as plume passage time, instantaneous maximum hazards irradiation, inhalation, deposit) due to an accident spreading out radioactive or chemical pollution into the atmosphere, from a source point, a stack release, (with heightening calculation) outspread sources (transport accident such as, for instance, road fire or car crash) or from a cylindrical cloud defined by different vertical sources (for instance pyrotechnical accident, missile firing...). The diffusion code DOURY type (french official methods) is written in FORTRAN. Data are entered in a conversational mode with auto-checking. Results are output to tables an isorisks curves drawn at map scales. At the Bruyeres-le-Chatel Radiation Protection Unit, a team is on permanent duty, can carry out results in a few minutes and transmit the evaluation by TELEFAX anywhere on the National territory [fr

  15. 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.

  16. A mechanism to compensate undesired stiffness in joints of prosthetic hands.

    Science.gov (United States)

    Smit, Gerwin; Plettenburg, Dick; Van der Helm, Frans

    2014-04-01

    Cosmetic gloves that cover a prosthetic hand have a parasitic positive stiffness that counteracts the flexion of a finger joint. Reducing the required input torque to move a finger of a prosthetic hand by compensating the parasitic stiffness of the cosmetic glove. Experimental, test bench. The parasitic positive stiffness and the required input torques of a polyvinyl chloride glove and a silicone glove were measured when flexing a metacarpophalangeal finger joint for 90°. To compensate this positive stiffness, an adjustable compensation mechanism with a negative stiffness was designed and built. A MATLAB model was created to predict the optimal settings of the mechanism, based on the measured stiffness, in order to minimize the required input torque of the total system. The mechanism was tested in its optimal setting with an applied glove. The mechanism reduced the required input torque by 58% for the polyvinyl chloride glove and by 52% for the silicone glove. The total energy dissipation of the joint did not change significantly. This study shows that the undesired positive stiffness in the joint can be compensated with a relatively simple negative stiffness mechanism, which fits inside a finger of a standard cosmetic glove. Clinical relevance This study presents a mechanism that compensates the undesired stiffness of cosmetic gloves on prosthetic hands. As a result, it requires less input force, torque and energy to move the fingers. Application of this mechanism in body-powered hands will reduce the control effort of the user.

  17. 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

  18. 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/.

  19. 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

  20. New Two-Mode Canonical Operator Realization of Angular Momentum and Generalized Fractional Fourier Transformation Obtained via Entangled State Representation

    Science.gov (United States)

    Fan, Hong-yi; Chen, Jun-hua; Low, Sen-yue

    2014-08-01

    By virtue of two mutually conjugate bipartite entangled state representations | η> and | ξ> (Fan and Klauder, Phys Rev A 49:704, 1994) we find new canonical operator realization (COR) of angular momentum. As its two applications, we point out that the COR helps to develop Schwinger bosonic realization theory, and can generalize the concept of FrFT, i.e., constructing new 2-dimensioanl fractional Fourier transformation with additivity.

  1. 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

  2. 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.

  3. Robust H∞cost guaranteed integral sliding mode control for the synchronization problem of nonlinear tele-operation system with variable time-delay.

    Science.gov (United States)

    Al-Wais, Saba; Khoo, Suiyang; Lee, Tae Hee; Shanmugam, Lakshmanan; Nahavandi, Saeid

    2018-01-01

    This paper is devoted to the synchronization problem of tele-operation systems with time-varying delay, disturbances, and uncertainty. Delay-dependent sufficient conditions for the existence of integral sliding surfaces are given in the form of Linear Matrix Inequalities (LMIs). This guarantees the global stability of the tele-operation system with known upper bounds of the time-varying delays. Unlike previous work, in this paper, the controller gains are designed but not chosen, which increases the degree of freedom of the design. Moreover, Wirtinger based integral inequality and reciprocally convex combination techniques used in the constructed Lypunove-Krasoviskii Functional (LKF) are deemed to give less conservative stability condition for the system. Furthermore, to relax the analysis from any assumptions regarding the dynamics of the environment and human operator forces, H ∞ design method is used to involve the dynamics of these forces and ensure the stability of the system against these admissible forces in the H ∞ sense. This design scheme combines the strong robustness of the sliding mode control with the H ∞ design method for tele-operation systems which is coupled using state feedback controllers and inherit variable time-delays in their communication channels. Simulation examples are given to show the effectiveness of the proposed method. Copyright © 2017 ISA. All rights reserved.

  4. 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.

  5. Studies and research concerning BNFP: operational assessment of the FSV-1 (HTGR) spent fuel shipping cask in alternate modes

    International Nuclear Information System (INIS)

    McCreery, P.N.

    1981-11-01

    This report presents an operational assessment of the FSV-1 spent fuel shipping cask which was developed by General Atomic specifically for the Fort St. Vrain reactor. Of primary interest is the adaptation to underwater loading and unloading of light-water-reactor (LWR) fuel in this cask which was designed for the dry-handling of high temperature gas cooled reactor (HTGR) fuel. Also presented is a concept for a system to compare the pros and cons of wet and dry handling of this and other casks

  6. 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.

  7. Thermal environment in simulated offices with convective and radiant cooling systems under cooling (summer) mode of operation

    DEFF Research Database (Denmark)

    Mustakallio, Panu; Bolashikov, Zhecho Dimitrov; Kostov, Kalin

    2016-01-01

    calculated. Manikin-based equivalent temperature (MBET) was determined by using two thermal manikins to identify the impact of the local thermal conditions generated by the studied systems on occupants' thermal perception. The results revealed that the differences in the thermal conditions achieved...... and occupants were simulated to obtain two different heat load conditions: 38 W/m2 and 64 W/m2 in the case of office room, and 71 W/m2 and 86 W/m2 in the case of meeting room. Air temperature, globe (operative) temperature, radiant asymmetry, air velocity and turbulent intensity were measured and draught rate...

  8. Cycles of undesirable substances in the food chain; Kreislaeufe unerwuenschter Stoffe in der Lebensmittelkette

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    The working group ''Carry over of undesirable substances in animal feed'' at the Federal Ministry of Food, Agriculture and Forestry (BMELV) in cooperation with the Institute of Animal Nutrition of the Friedrich-Loeffler-Institute (FLI) performed on 27 and 28 October 2011 in Braunschweig a workshop on ''cycles of undesirable substances in Food Chain ''. The aim of the workshop was to present the latest findings of research and Carry over Recommendations of the Carry over - Working Group on undesirable substances in feed and production processes of the feed industry, to evaluate and discuss about this with representatives from science, business and management and to work out the further research and action need. The focus of the considerations were the pathways, the carry over and the Exposure to dioxins and other halogenated hydrocarbons, the effects of Mycotoxins in feed and starting points for preventive measures, the soil contamination and the exposure of humans and animals by cadmium and case studies on Nitrite in feed, antibiotics in plants and residues of pesticides and radionuclides in feed. Furthermore the risks associated with specified manufacturing processes of feed are considered, especially the used materials that come into contact with animal feed, and the risks from nanotechnology. [German] Die Arbeitsgruppe ''Carry over unerwuenschter Stoffe in Futtermitteln'' beim Bundesministerium fuer Ernaehrung, Landwirtschaft und Forsten (BMELV) hat in Zusammenarbeit mit dem Institut fuer Tierernaehrung des Friedrich-Loeffler-Instituts (FLI) am 27. und 28. Oktober 2011 in Braunschweig einen Workshop zum Thema ''Kreislaeufe unerwuenschter Stoffe in der Lebensmittelkette'' durchgefuehrt. Ziel des Workshops war es, die aktuellen Erkenntnisse der Carry over Forschung und die Empfehlungen der Carry over - Arbeitsgruppe zu unerwuenschten Stoffen in Futtermitteln und Produktionsverfahren in

  9. 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.

  10. 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.

  11. 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.

  12. Foreign Operation Methods

    DEFF Research Database (Denmark)

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

    Introduction and theory -- Introduction -- Theoretical approaches -- Modes of operation -- Franchising -- Licensing -- Management contracts -- International subcontracting -- Project operations -- Exports -- Alliances -- Foreign direct investment -- Strategies -- Mode switching and stretching...

  13. Research on China's aquaculture efficiency evaluation and influencing factors with undesirable outputs

    Science.gov (United States)

    Ji, Jianyue; Wang, Pingping

    2015-06-01

    Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.

  14. The application of game theory and cognitive economy to analyze the problem of undesired location

    International Nuclear Information System (INIS)

    Villani, S.

    2008-01-01

    The analysts of the processes of public bodies decision - taking have long been discussing on the establishment of proper strategies to manage environmental conflicts - above all the so-called problems of undesired location of public works and facilities - efficiently (i.e. on a short-period basis so as to grant decision and agreement stability) and fairly (the parties' satisfaction is itself a further guarantee of decision and agreement stability). Each strategy, anyway, is still in progress, like a universe to create and explore. Therefore, in this paper, we will focus on the analysis of the problem and provide as well some theoretical proposals to arrange a new interpreting model of public bodies decision-taking processes based on the achievements of two new subject-matters: evolutionary game theory and cognitive economy. Both sciences share their investigation field with law and economic science. [it

  15. Undesirable sulphur and carbonyl flavor compounds in UHT milk: a review.

    Science.gov (United States)

    Zabbia, Alex; Buys, Elna M; De Kock, Henriette L

    2012-01-01

    Ultra High Temperature (UHT) processing leads to the formation of "cooked" and "flat" flavors in milk. These undesirable notes occur due to the volatile formation of a variety of sulphur containing compounds, methyl ketones and aliphatic aldehydes, derived from the constituents of the milk's matrix during thermal processing and storage. The "cooked" flavor of UHT milk is associated with the presence of a variety of sulphur containing compounds while the "stale" flavor is characterized by the dissipation of these sulphur volatiles and an increase of the formation and presence of both methyl ketones and aliphatic aldehydes over time. The extent to which the individual volatiles contribute to the overall flavor of UHT milk is not clear. The proposed formation of these volatiles, that is, the methods to control the intensity of "cooked" and "stale" flavors associated with UHT milk and extraction techniques for the isolation of these volatiles from milk, have been reviewed.

  16. Controlling threshold voltage and leakage currents in vertical organic field-effect transistors by inversion mode operation

    Science.gov (United States)

    Günther, Alrun A.; Hossbach, Christoph; Sawatzki, Michael; Kasemann, Daniel; Bartha, Johann W.; Leo, Karl

    2015-12-01

    The interest in vertical organic transistors as a means to overcome the limitations of conventional organic field-effect transistors (OFETs) has been growing steadily in recent years. Current vertical architectures, however, often suffer from a lack of parameter control, as they are limited to certain materials and processing techniques, making a controlled shift of, e.g., the transistor threshold voltage difficult. In this contribution, we present a vertical OFET (VOFET) operating in the inversion regime. By varying the thickness or doping concentration of a p-doped layer in an otherwise n-type VOFET, we are able to shift the threshold voltage in a controlled manner from 1.61 V (for a normal n-type VOFET) to 4.83 V (for the highest doping concentration of 50 mol. %). Furthermore, it is found that low doping concentrations of 20 mol. % can improve the Off state of the VOFET through reduction of the source-drain leakage current.

  17. 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.

  18. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, In Chul [Youngdong University, Youngdong (Korea, Republic of)

    2011-10-15

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  19. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    International Nuclear Information System (INIS)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup; Lee, In Chul

    2011-01-01

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  20. BETWEEN THE RIGHT AND THE COMMON. HOW GROUPS REACT TO SOCIALLY UNDESIRABLE BEHAVIOUR

    Directory of Open Access Journals (Sweden)

    Komendant-Brodowska Agata

    2017-06-01

    Full Text Available The aim of the paper is to analyse the relationship between group characteristics and the scope of reaction of the group to socially undesirable behaviour. Sometimes small groups or communities fail to react to undesirable or violent behaviour and their apathy can have devastating consequences. Such a situation can occur among co-workers witnessing workplace mobbing, or neighbours who do not react to a suspicion of domestic violence. Reasons for their inaction are diverse and can include fear, doubts concerning the necessity of such a reaction, and also conformity. In the paper I examine a seemingly favourable situation: I assume that reaction is costless and all the members of the group would like to react (internalised norm, but they also want to conform. In order to analyse the factors that can influence the scope of group reaction, a structurally embedded sequential coordination game was played for different initial conditions. Computer simulations were conducted for networks of a specific type (Erd¨os-R´enyi random graph. The main aim of the analysis was to identify non-structural and structural features of the group that can impede or even block the intervention of the group. There is a positive relationship between the scope of group reaction and the strength of the internalized norm, whereas the level of conformity affects the chances of group intervention in a negative way. Heterogeneity of the group is an important factor - the scope of reaction is higher when members of the group have different levels of norm internalisation and conformity. There is a non-linear relationship between network density and the scope of reaction. Both low and high density can make it harder for people to act.

  1. 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.

  2. Failure mode of valve-regulated lead-acid batteries under high-rate partial-state-of-charge operation

    Science.gov (United States)

    Lam, L. T.; Haigh, N. P.; Phyland, C. G.; Urban, A. J.

    Within the next decade, there will be major changes in automotive technology with the introduction of several new features which will increase significantly the on-board power requirements. This high power demand is beyond the capability of present 14 V alternators and thus a 42 V power network is to be adopted. The new 'PowerNet' requires the lead-acid battery to be capable of providing a large number of shallow discharge-charge cycles at a high rate. High-rate discharge is necessary for engine cranking and power assist, while high-rate charge is associated with regenerative braking. The battery will operate at these high rates in a partial-state-of-charge condition, so-called HRPSoC duty. Under simulated HRPSoC duty, it is found that the valve-regulated lead-acid (VRLA) battery fails prematurely due to the progressive accumulation of lead sulfate mainly on the surfaces of the negative plates. This is because the lead sulfate cannot be converted efficiently back to sponge lead during charging either from the engine or from regenerative braking. Eventually, the layer of lead sulfate develops to such extent that the effective surface area of the plate is reduced markedly and the plate can no longer deliver the high cranking-current demanded by the automobile. A mechanistic analysis of battery operation during HRPSoC duty shows that high-rate discharge is the key factor responsible for the build-up of the lead sulfate layer. Such discharge causes a compact layer of tiny lead sulfate crystals to form on the surface of the negative plate and subsequent charging gives rise to an early evolution of hydrogen. Hydrogen evolution is further exacerbated when a high charging current is used.

  3. Study of different operational modes of the IAP 2-port-DOAS instrument for investigation of atmospheric trace gases during CINDI-2 campaign

    Science.gov (United States)

    Borovski, A.; Elokhov, A.; Postylyakov, O.; Bruchkouski, I.

    2017-10-01

    An instrument for measuring atmospheric trace gases by DOAS method using scattered solar radiation was developed in A.M.Obukhov IAP RAS. The instrument layout is based on the lab Shamrock 303i spectrograph supplemented by 2-port radiation input system employing optical fiber. Optical ports may be used with a fixed telescope or with a scanning MAX-DOAS unit. In September 2016 the IAP instrument participated in the 2nd Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments (CINDI-2) campaign, held in the Netherlands. About 40 instruments from 26 different organizations performed DOAS measurement of NO2, HCHO and other trace gases during the campaign. During the campaign the optical ports of IAP instrument had telescopes A and B with similar field of view of about 0.3°. Telescope A was always directed to the zenith. Telescope B was directed at 5° elevation angle. Two gratings were installed in the spectrometer. They provide different spectral resolution (FWHM 0.4 and 0.8 nm respectively) and spectral window width ( 70 and 140 nm respectively). During CINDI-2 campaign we performed test measurements in UV and visible wavelength ranges to investigate instrument stability and retrieval errors of NO2 and HCHO contents. We test four operational mode of the instrument in which we used fixed grating position in UV or visible spectral region, or rotate grating between UV and visible, or change gratings using a turret. Here we present preliminary results of comparison of gas content measured by IAP instrument with the median gas content obtained on the basis of measurements of all groups participated in CINDI-2 campaign. The main goal of the study was the detailed comparison of all four modes of our instrument and understanding of probable biases and errors typical for these modes. It was found that rotation of grating turret does not significantly affected on quality of NO2 DSCD retrieval and is much more significant for HCHO DSCD retrieval.

  4. Frequency-tuning radiofrequency plasma source operated in inductively-coupled mode under a low magnetic field

    Science.gov (United States)

    Takahashi, Kazunori; Nakano, Yudai; Ando, Akira

    2017-07-01

    A radiofrequency (rf) inductively-coupled plasma source is operated with a frequency-tuning impedance matching system, where the rf frequency is variable in the range of 20-50 MHz and the maximum power is 100 W. The source consists of a 45 mm-diameter pyrex glass tube wound by an rf antenna and a solenoid providing a magnetic field strength in the range of 0-200 Gauss. A reflected rf power for no plasma case is minimized at the frequency of ˜25 MHz, whereas the frequency giving the minimum reflection with the high density plasma is about 28 MHz, where the density jump is observed when minimizing the reflection. A high density argon plasma above 1× {{10}12} cm-3 is successfully obtained in the source for the rf power of 50-100 W, where it is observed that an external magnetic field of a few tens of Gauss yields the highest plasma density in the present configuration. The frequency-tuning plasma source is applied to a compact and high-speed silicon etcher in an Ar-SF6 plasma; then the etching rate of 8~μ m min-1 is obtained for no bias voltage to the silicon wafer, i.e. for the case that a physical ion etching process is eliminated.

  5. Ultimate Disposal of High-Level Radioactive Wastes - Fixation in Phosphate Glass with Emphasis on the Continuous Mode of Plant Operation

    International Nuclear Information System (INIS)

    Hatch, L.P.; Weth, G.C.; Tuthill, E.J.

    1963-01-01

    In the study of ultimate disposal of high-level radioactive wastes at Brookhaven National Laboratory emphasis is being placed on the formation of phosphate glasses as a means of incorporating the fission products in stable media. Of primary interest here is the development of a process in which the entire conversion from the raw aqueous wastes to the final.glass product would be carried out in an all-liquid system. The phosphate-glass method offers a number of important advantages in this respect and, in particular, lends itself to the development of a continuous process in which the liquid medium would be readily transferable from one process step to another. The paper presents the results of bench-scale studies on the production of phosphate glasses, with the continuous mode of operation, utilizing various types of aqueous wastes. The studies have been in progress for some 20 months and were carried out to determine essential operating parameters with particular attention paid to corrosion resistance and physical integrity of the high-temperature crucible. In addition, the paper discusses flow-sheet development together with the design and results of operation of. an engineering-scale plant having a capacity of 0.5 ft 3 of glass per day with a continuous feed of simulated non-radioactive wastes. (author) [fr

  6. Analytical prediction and experimental verification of performance at various operating conditions of a dual-mode traveling wave tube with multistage depressed collectors

    Science.gov (United States)

    Dayton, J. A., Jr.; Kosmahl, H. G.; Ramins, P.; Stankiewicz, N.

    1981-01-01

    A comparison of analytical and experimental results is presented for a high performance dual-mode traveling wave tube (TWT) operated over a wide range conditions. The computations are carried out with advanced multidimensional computer programs. These programs model the electron beam as a series of disks or rings of charge and follow their trajectories from the rf input of the TWT through the slow-wave structure refocusing system to their points of impacts in the depressed collector. TWT performance, collector efficiency, and collector current distribution are computed and compared with measurements. Very good agreement was obtained between computed and measured TWT performance and collector efficiencies, and the computer design of a highly efficient collector was demonstrated.

  7. 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.

  8. Calculation of the operation mode of the emergency condenser (EC) of the INKA test facility with ATHLET

    Energy Technology Data Exchange (ETDEWEB)

    Wilschuetz, H.G. [E.ON Kernkraft GmbH, Hannover (Germany); Leyer, S. [AREVA NP GmbH, Offenbach (Germany); Kruessenberg, A.K.; Schaefer, F. [FZD Forschungszentrum Dresden-Rossendorf e.V. (Germany)

    2010-05-15

    On 4{sup th} of April 2008 AREVA and E.ON signed a cooperation agreement. An essential part of this is the Final Basic Design Contract SWR 1000. On 28{sup th} of November 2008 AREVA and E.ON have signed a Memorandum of Understanding to develop a commercially viable product and to focus on the successful deployment of the SWR 1000 in a collaborative manner. Meanwhile a rebranding was conducted: the new name of this evolutionary boiling water reactor of the Generation III+ is KERENATM trademark. It is the common intention of AREVA and E.ON to complete the basic design until the end of 2010 so as to reach a design ready for bid and ready for licensing for a construction primarily in a European country. The KERENA trademark is not a completely new plant concept, it is a proven further developed design, based on Gundremmingen NPP and the whole accumulated German BWR operating experience. The design shall fulfill the following major safety items: - further reduction of core damage frequency, - control of postulated core melt accident by in-vessel melt retention without emergency response actions, - introduction of passive safety systems (principle of diversity and redundancy), and - long grace periods for manual intervention (> 3 days). Especially for the newly introduced passive safety systems, which are described in detail, not only an experimental testing and validation is needed, but also thermal-hydraulic system codes have to be qualified, to be able to consider the mostly gravity driven 3D-flow phenomena correctly. Since in some countries the code ATHLET is well established, it is useful to prove its capabilities or to enhance the capabilities, if necessary. Therefore the FZD (Forschungszentrum Dresden-Rossendorf) is performing a model development and calculations for code validation of the test results from INKA (INtegral test facility in KArlstein, Germany). This paves the way for licensing procedures later on. (orig.)

  9. 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.

  10. Undesired small RNAs originate from an artificial microRNA precursor in transgenic petunia (Petunia hybrida.

    Directory of Open Access Journals (Sweden)

    Yulong Guo

    Full Text Available Although artificial microRNA (amiRNA technology has been used frequently in gene silencing in plants, little research has been devoted to investigating the accuracy of amiRNA precursor processing. In this work, amiRNAchs1 (amiRchs1, based on the Arabidopsis miR319a precursor, was expressed in order to suppress the expression of CHS genes in petunia. The transgenic plants showed the CHS gene-silencing phenotype. A modified 5' RACE technique was used to map small-RNA-directed cleavage sites and to detect processing intermediates of the amiRchs1 precursor. The results showed that the target CHS mRNAs were cut at the expected sites and that the amiRchs1 precursor was processed from loop to base. The accumulation of small RNAs in amiRchs1 transgenic petunia petals was analyzed using the deep-sequencing technique. The results showed that, alongside the accumulation of the desired artificial microRNAs, additional small RNAs that originated from other regions of the amiRNA precursor were also accumulated at high frequency. Some of these had previously been found to be accumulated at low frequency in the products of ath-miR319a precursor processing and some of them were accompanied by 3'-tailing variant. Potential targets of the undesired small RNAs were discovered in petunia and other Solanaceae plants. The findings draw attention to the potential occurrence of undesired target silencing induced by such additional small RNAs when amiRNA technology is used. No appreciable production of secondary small RNAs occurred, despite the fact that amiRchs1 was designed to have perfect complementarity to its CHS-J target. This confirmed that perfect pairing between an amiRNA and its targets is not the trigger for secondary small RNA production. In conjunction with the observation that amiRNAs with perfect complementarity to their target genes show high efficiency and specificity in gene silencing, this finding has an important bearing on future applications of ami

  11. Two-stage coal liquefaction process materials from the Wilsonville Facility operated in the nonintegrated and integrated modes: chemical analyses and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Later, D.W.

    1985-01-01

    This document reports the results from chemical analyses and biological testing of process materials sampled during operation of the Wilsonville Advanced Coal Liquefaction Research and Development Facility (Wilsonville, Alabama) in both the noncoupled or nonintegrated (NTSL Run 241) and coupled or integrated (ITSL Run 242) two-stage liquefaction operating modes. Mutagenicity and carcinogenicity assays were conducted in conjunction with chromatographic and mass spectrometric analyses to provide detailed, comparative chemical and biological assessments of several NTSL and ITSL process materials. In general, the NTSL process materials were biologically more active and chemically more refractory than analogous ITSL process materials. To provide perspective, the NTSL and ITSL results are compared with those from similar testing and analyses of other direct coal liquefaction materials from the solvent refined coal (SRC) I, SRC II and EDS processes. Comparisons are also made between two-stage coal liquefaction materials from the Wilsonville pilot plant and the C.E. Lummus PDU-ITSL Facility in an effort to assess scale-up effects in these two similar processes. 36 references, 26 figures, 37 tables.

  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

    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.

  14. 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.

  15. The presence of undesirable mould species on the surface of dry sausages

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2008-01-01

    Full Text Available Transition from manufacture to the industrial way of meat production and processing, as well as contemporary concept of food quality and safety, have led to the application of starter cultures. Their application leads towards the streamlining of the production process in the desired direction, quality improvement and its harmonization, and thereby to its standardization. Application of moulds in the meat industry is based on positive effects of their proteolytic and lipolytic egzoenzymes which, as a consequence, leads to the creation of characteristic sensory properties ('flavor' of fermented products. Penicillium nalgiovense is a typical representative of moulds used in the production of fermented sausages-salamis from our region. Samples of 'zimska salama' (dry sausage, produced with Penicillium nalgiovense, were evaluated as hygienically unacceptable. Their sensory properties changed due to contamination of this mould during the ripening process. Micological analysis discovered the presence of Penicillium aurantiogriseum, which is a frequent mould contaminant in the meat industry. At the same time, thin layer chromatography revealed no possibility of metabolic activity of this mould in the creation of mycotoxins. However, the presence of this mould on the surface of 'zimska salama' is considered as undesirable due to formation of 'off flavor' in products. Such product is considered as hygienically unacceptable and cannot be used for the human consumption.

  16. On the undesired frequency chirping in photonic time-stretch systems

    Science.gov (United States)

    Xu, Yuxiao; Chi, Hao; Jin, Tao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

    2017-12-01

    The technique of photonic time stretch (PTS) has been intensively investigated in the past decade due to its potential in the acquisition of ultra-high speed signals. The frequency-related RF power fading in the PTS systems with double sideband (DSB) modulation has been well-known, which limits the maximum modulation frequency. Some solutions have been proposed to solve this problem. In this paper, we report another effect, i.e., undesired frequency chirping, which also relates to the performance degradation of PTS systems with DSB modulation, for the first time to our knowledge. Distinct from the nonlinearities caused by nonlinear modulation and square-law photodetection, which is common in radio frequency analog optical links, this frequency chirping originates from the addition of two beating signals with a relative delay after photodetection. A theoretical model for exactly describing the frequency chirping is presented, and is then verified by simulations. Discussion on the method to avoid the frequency chirping is also presented.

  17. Regime Shifts and Ecosystem Service Generation in Swedish Coastal Soft Bottom Habitats: When Resilience is Undesirable

    Directory of Open Access Journals (Sweden)

    Max Troell

    2005-06-01

    Full Text Available Ecosystems can undergo regime shifts where they suddenly change from one state into another.  This can have important implications for formulation of management strategies, if system characteristics develop that are undesirable from a human perspective, and that have a high resistance to restoration efforts. This paper identifies some of the ecological and economic consequences of increased abundance of filamentous algae on shallow soft bottoms along the Swedish west coast. It is suggested that a successive increase in the sediment nutrient pool has undermined the resilience of these shallow systems. After the regime shift has occurred, self-generation properties evolve keeping the system locked in a high-density algae state. The structural and functional characteristics of the new system state differ significantly from the original one, resulting in less valuable ecosystem goods and services generated for society. In Sweden, loss of value results from the reduced capacity for mitigating further coastal eutrophication, reduced habitat quality for commercial fishery species, and the loss of aesthetic and recreational values.

  18. Tracking Progress in Improving Diagnosis: A Framework for Defining Undesirable Diagnostic Events.

    Science.gov (United States)

    Olson, Andrew P J; Graber, Mark L; Singh, Hardeep

    2018-01-29

    Diagnostic error is a prevalent, harmful, and costly phenomenon. Multiple national health care and governmental organizations have recently identified the need to improve diagnostic safety as a high priority. A major barrier, however, is the lack of standardized, reliable methods for measuring diagnostic safety. Given the absence of reliable and valid measures for diagnostic errors, we need methods to help establish some type of baseline diagnostic performance across health systems, as well as to enable researchers and health systems to determine the impact of interventions for improving the diagnostic process. Multiple approaches have been suggested but none widely adopted. We propose a new framework for identifying "undesirable diagnostic events" (UDEs) that health systems, professional organizations, and researchers could further define and develop to enable standardized measurement and reporting related to diagnostic safety. We propose an outline for UDEs that identifies both conditions prone to diagnostic error and the contexts of care in which these errors are likely to occur. Refinement and adoption of this framework across health systems can facilitate standardized measurement and reporting of diagnostic safety.

  19. Combined rotor fault diagnosis in rotating machinery using empirical mode decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sukhjeet; Kumar, Navin [Indian Institute of Technology, Ropar Rupnagar (India)

    2014-12-15

    Unbalance, misalignment, partial rub, looseness and bent rotor are one of the most commonly observed faults in rotating machines. These faults cause breakdowns in rotating machinery and create undesired vibrations while operating. In this study, an approach to detect combined fault of unbalance and bent rotors for advance detection of the features of the fault rotors diagnosis is proposed. Empirical mode decomposition (EMD) is used efficiently to decompose the complex vibration signals of rotating machinery into a known number of intrinsic mode functions so that the fault characteristics of the unbalanced and bowed shaft can be examined in the time-frequency Hilbert spectrum. A test bench of Spectra-Quest has been used for performing experiments to illustrate the unbalance and the bent rotor conditions as well as the healthy rotor condition. Analysis of the results shows the usefulness of proposed approach in diagnosing the unbalance and bowed fault of the shaft in rotating machinery.

  20. Role of Fault Attributions and Other Factors in Adults' Attitudes Toward Hypothetical Children With an Undesirable Characteristic.

    Science.gov (United States)

    Wadian, Taylor W; Sonnentag, Tammy L; Jones, Tucker L; Barnett, Mark A

    2018-01-01

    A total of 184 adults read descriptions of six hypothetical children with various undesirable characteristics (i.e., being extremely overweight, extremely aggressive, extremely shy, a poor student, a poor athlete, displaying symptoms of attention deficit hyperactivity disorder). Following each description, the participants were asked to rate how much they disagree or agree that the child, the child's parents, and the child's biological condition (i.e., "something wrong inside the child's body or brain") are at fault for the onset and the perpetuation of the undesirable characteristic. In addition, the participants were asked to rate their attitude toward each child using a 100-point "feeling thermometer." Analyses of the participants' various fault attribution ratings revealed that they tended to agree more strongly that a child's parents and his/her biological condition are at fault for the onset and the perpetuation of the child's undesirable characteristic than is the child him/herself. Despite the participants' reluctance to blame a hypothetical child for his/her undesirable characteristic, regression analyses revealed that, in general, the more they blamed the child for the onset of his/her undesirable characteristic, the more negative their attitude was toward the child. However, the participants' ratings of the extent to which the child's parents or biological condition are at fault for the onset and the perpetuation of the child's undesirable characteristic were not found to be associated with their attitude toward any of the children. Similarities and differences between the present findings and those reported in prior studies involving younger individuals are addressed.

  1. A tandem laboratory scale protein purification process using Protein A affinity and anion exchange chromatography operated in a weak partitioning mode.

    Science.gov (United States)

    Shamashkin, Michael; Godavarti, Ranga; Iskra, Timothy; Coffman, Jon

    2013-10-01

    A significant consequence of scaling up production of high titer monoclonal antibody (mAb) processes in existing facilities is the generation of in-process pools that exceed the capacity of storage vessels. A semi-continuous downstream process where columns and filters are linked and operated in tandem would eliminate the need for intermediate holding tanks. This study is a bench-scale demonstration of the feasibility of a tandem process for the purification of mAbs employing an affinity Protein A capture step, followed by a flow-through anion-exchange (AEX) step with the possibility of adding an in-line virus filtration step (VF). All three steps were linked sequentially and operated as one continuous process using an ÄKTA FPLC equipped with two pumps and a system of valves and bypasses that allowed the components to be engaged at different stages of the process. The AEX column was operated in a weak partitioning (WP) mode enabled by a precise in-line titration of Protein A effluent. In order to avoid complex control schemes and facilitate validation, quality and robustness were built into the system through selection of buffers based on thermodynamic and empirical models. The tandem system utilized the simplest possible combination of valves, pumps, controls, and automation, so that it could easily be implemented in a clinical or commercial production facility. Linking the purification steps in a tandem process is expected to generate savings in time and production costs and also reduce the size of quality systems due to reduced documentation requirements, microbial sampling, and elimination of hold time validation. Copyright © 2013 Wiley Periodicals, Inc.

  2. Quantifying undesired parallel components in Thévenin-equivalent acoustic source parameters

    DEFF Research Database (Denmark)

    Nørgaard, Kren Rahbek; Neely, Stephen T.; Rasetshwane, Daniel M.

    2018-01-01

    in the source parameters. Such parallel components can result from, e.g., a leak in the ear tip or improperly accounting for evanescent modes, and introduce errors into subsequent measurements of impedance and reflectance. This paper proposes a set of additional error metrics that are capable of detecting...

  3. 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.

  4. Techniques Use by Science, Technology and Mathematics (STM) Teachers for Controlling Undesirable Classroom Behaviours in Anambra State Secondary Schools

    Science.gov (United States)

    Chinelo, Okigbo Ebele; Nwanneka, Okoli Josephine

    2016-01-01

    This study investigated the techniques used by secondary school Science Technology and Mathematics (STM) teachers in controlling undesirable behaviours in their classrooms. It adopted descriptive survey design in which 178 Anambra State teachers teaching STM subjects in senior secondary were involved in the research. Two sections of questionnaire…

  5. The Emperor’s New Clothing: National Responses to “Undesirable and Unreturnable” Aliens under Asylum and Immigration Law

    NARCIS (Netherlands)

    Cantor, David James; van Wijk, J.; Singer, Sarah; Bolhuis, M.P.

    2017-01-01

    The “scandal” of foreign criminals whom our governments cannot send back to their own countries has become something of a tabloid obsession. Yet, while suspected or convicted of serious crimes or considered to pose a danger to society, such “undesirable and unreturnable” aliens equally often

  6. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Science.gov (United States)

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A.

    2013-07-01

    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 spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  7. A Thomson-type mass and energy spectrometer for characterizing ion energy distributions in a coaxial plasma gun operating in a gas-puff mode

    Energy Technology Data Exchange (ETDEWEB)

    Rieker, G. B.; Poehlmann, F. R.; Cappelli, M. A. [High Temperature Gasdynamics Laboratory, Stanford University, Stanford, California 94305 (United States)

    2013-07-15

    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 spectrometer was designed and calibrated using the Geant4 toolkit, accounting for the effects on the ion trajectories of spatial non-uniformities in the spectrometer magnetic and electric fields. Results for hydrogen gas puffs indicate the existence of a class of accelerated protons with energies well above the coaxial discharge potential (up to 24 keV). The Thomson analyzer confirms the presence of impurities of copper and iron, also of relatively high energies, which are likely erosion or sputter products from plasma-electrode interactions.

  8. Dual-Mode Combustor

    Science.gov (United States)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  9. Phosphate binders affect vitamin K concentration by undesired binding, an in vitro study.

    Science.gov (United States)

    Neradova, A; Schumacher, S P; Hubeek, I; Lux, P; Schurgers, L J; Vervloet, M G

    2017-05-02

    Vascular calcification is a major contributing factor to mortality in end stage renal disease (ESRD). Despite the efficacy of phosphate binders to improve hyperphosphatemia, data on vascular calcification are less clear. There seems to be a difference in attenuation or delay in progression between different binders. In this in vitro experiment we tested whether phosphate binders could limit bioavailability of vitamin K2 by undesired binding. Vitamin K-deficiency limits activation of the vascular tissue mineralization inhibitor matrix γ-carboxyglutamate (Gla) protein (MGP) thereby exacerbating vascular calcification. In this experiment vitamin K2 (menaquinone-7; MK-7) binding was assessed by adding 1 mg of vitamin K2 to a medium with pH 6 containing 67 mg phosphate binder with either 7 mg of phosphate or no phosphate. Five different phosphate binders were tested. After five and a half hours vitamin K was analyzed by HPLC. All experiments were performed in triplicate. Sucroferric-oxyhydroxide and sevelamer carbonate did not significantly bind vitamin K2, both in solution only containing vitamin K2 or in combination with phosphate. Calcium acetate/magnesium carbonate binds vitamin K2 strongly both in absence (p = 0.001) and presence of phosphate (p = 0.003). Lanthanum carbonate significantly binds vitamin K2 in solution containing only vitamin K2 (p = 0.005) whereas no significant binding of vitamin K2 was observed in the solution containing vitamin K2 and phosphate (p = 0.462). Calcium carbonate binds vitamin K2 significantly in a solution with vitamin K2 and phosphate (p = 0.009) whereas without phosphate no significant binding of vitamin K2 was observed (p = 0.123). Sucroferric-oxyhydroxide and sevelamer carbonate were the only binders of the five binders studied that did not bind vitamin K2 in vitro. The presence or absence of phosphate significantly interferes with vitamin K2 binding so phosphate binders could potentially limit

  10. Design of low DMD few-mode optical fibers with extremely enlarged core diameter providing nonlinearity suppression for operating over "C"-band central region

    Science.gov (United States)

    Andreev, Vladimir A.; Bourdine, Anton V.; Burdin, Vladimir A.; Evtushenko, Alexander S.; Halikov, Rashid H.

    2017-04-01

    We present method for design of refractive index profile for silica GeO2-doped graded-index few-mode optical fibers with reduced differential mode delay and suppressed mode nonlinearity due to extremely enlarged core diameter up to 42 μm. Proposed solution is based on earlier on developed modified Gaussian approximation generalized for analysis of silica weakly guiding optical fibers with single outer cladding and arbitrary axially-symmetric refractive index profile, that provides ability to derive analytical expressions for guided mode delays. Therefore the objective function is represented as a sum of squares of deviations between mode staff delays and reference value corresponding to refractive index profile of current iteration. Based on developed method we performed computation for various combination of the reference mode delay and first iteration profile parameter. Some results of desired graded-index profile for a few-mode optical fibers 42/125 providing differential mode delay minimization over central region of "C"-band are represented.

  11. Study of a pilot photovoltaic-electrolyser-fuel cell power system for a geothermal heat pump heated greenhouse and evaluation of the electrolyser efficiency and operational mode

    Directory of Open Access Journals (Sweden)

    Ileana Blanco

    2014-11-01

    Full Text Available The intrinsic factor of variability of renewable energy sources often limits their broader use. The photovoltaic solar systems can be provided with a power back up based on a combination of an electrolyser and a fuel cell stack. The integration of solar hydrogen power systems with greenhouse heating equipment can provide a possible option for powering stand-alone greenhouses. The aim of the research under development at the experimental farm of Department of Agro-Environmental Sciences of the University of Bari Aldo Moro is to investigate on the suitable solutions of a power system based on photovoltaic energy and on the use of hydrogen as energy vector, integrated with a ground source heat pump for greenhouse heating in a self sustained way. The excess energy produced by a purpose-built array of solar photovoltaic modules supplies an alkaline electrolyser; the produced hydrogen gas is stored in pressured storage tank. When the solar radiation level is insufficient to meet the heat pump power demand, the fuel cell starts converting the chemical energy stored by the hydrogen fuel into electricity. This paper reports on the description of the realised system. Furthermore the efficiency and the operational mode of the electrolyser were evaluated during a trial period characterised by mutable solar radiant energy. Anyway the electrolyser worked continuously in a transient state producing fluctuations of the hydrogen production and without ever reaching the steady-state conditions. The Faradic efficiency, evaluated by means of an empirical mathematic model, highlights that the suitable working range of the electrolyser was 1.5÷2.5 kW and then for hydrogen production more than 0.21 Nm3h–1.

  12. UNDESIRED REACTIONS AT THE UROGRAPHY IN THE CORRELATION OF THE IODIC AND THE NON-TODIC CONTRAST MEDIA

    Directory of Open Access Journals (Sweden)

    Rade R. Babić

    2000-07-01

    Full Text Available The paper analyzes the undesired reactions at 6053 urographies (IVU in thecorrelation of the iodic and the non-iodic contrast media (ICM.Depending on the allergological status the ICM (iodic or non-iodic is chosenfor the sake of carrying out an urographic examination as well as the necessarypremedication measures.The undesired reactions to the TCM are registered in 4,87% (1:20 TVU,namely in 5,6% (1:17 TVU to the iodic and in 2,39% (1:41 IVU to the non-iodicICM.At the intravenous application of the iodic ICM at the IVU the undesiredreactions are registered for2,4 times more often than at the application of the non-iodicICM.

  13. Order and control in the environment: Exploring the effects on undesired behaviour and the importance of locus of control

    OpenAIRE

    Jansen, A.M.; Giebels, Ellen; van Rompay, Thomas Johannes Lucas; Austrup, Sebastian; Junger, Marianne

    2017-01-01

    Purpose This study aimed at gaining more insight into the combined influence of environmental factors and personal vulnerability to environmental cues on cheating behaviour in a task-related indoor setting. We propose that a disorderly environment increases cheating as it implicitly signals that undesirable behaviours are common. Camera presence is expected to buffer these effects. We included locus of control (LOC) as a personality variable, as we expected individuals with an external LOC to...

  14. Qualitative and quantitative analyses of stroke dynamics and microfluidics of phacoemulsification probes operating in different modes.

    Science.gov (United States)

    Zacharias, Jaime

    2016-05-01

    To compare phacoemulsification (phaco) tip movement, microfluidic dynamics, and tip-to-load interaction between longitudinal, torsional, and elliptical ultrasound (US) modalities. Phacodynamics Laboratory, Clínica Oftalmológica, Pasteur, Santiago, Chile. Experimental study. All experiments were performed using a fluid-filled optical test chamber and phaco tips that were US power activated. Tip movement was evaluated using stroke tracing and stroboscopy imaging techniques. Qualitative and quantitative assessments of microfluidic behavior were performed using bead seeding and high-speed shadowgraphy imaging combined with particle-image velocimetry and vector analysis. Material load interaction was measured using a rubber sphere that represented lens material. Longitudinal and torsional US tips showed precise forward-and-backward and side-to-side (lateral) movement, respectively. Elliptical US tips scribed a 2-dimensional ellipsoid path that slightly changed in shape and orientation plane at higher powers. Longitudinal and lateral components of tip motion were evident in elliptical mode. Regular fluid flow was observed with longitudinal mode (forward-directed flow away from the aspiration port) and torsional mode (steady backflow into the aspiration port). In elliptical mode, bead repulsion, erratic bursts of acoustic streaming, oblique backflow, and areas of multidirectional flow were observed. The longitudinal mode caused the material load to bounce against the tip, whereas the torsional mode maintained a consistent load attraction. In elliptical mode, the material load rotated slightly and bounced away from the tip in irregular intervals when attraction was achieved. Tip movement, microfluidic behavior, and material load interaction were related within but varied across US modalities. The elliptical mode showed a movement pattern with longitudinal and lateral components and irregular microfluidic behaviors. Dr. Zacharias received research funding from Alcon

  15. Evolution of reactor control modes

    International Nuclear Information System (INIS)

    Mourlevat, J.L.

    2007-01-01

    The article reviews the different reactor control modes: mode A, mode G and mode X that are used in PWR reactors designed by Areva. The purpose of reactor controlling is to compensate reactivity effects (xenon poisoning and counter-reaction effects) generated by load changes. A control mode is the strategy followed by using both soluble boron and the control rods to handle these reactivity effects. Soluble boron plays an important role in mode A but is less efficiency toward the end-of-cycle. Generally soluble boron is used to compensate slow reactivity effects. Mode G is based on the optimization of the use of the control rods and allows a quick return to the nominal power. Mode X combines the uses of control rods and soluble boron to cope with the operator's wishes: sparing effluents or having a quick return to nominal power. The mode X appears to be more penalizing concerning the fuel-cladding interaction. (A.C.)

  16. Dual-cavity mode converter for a fundamental mode output in an over-moded relativistic backward-wave oscillator

    International Nuclear Information System (INIS)

    Li, Jiawei; Huang, Wenhua; Xiao, Renzhen; Bai, Xianchen; Zhang, Yuchuan; Zhang, Xiaowei; Shao, Hao; Chen, Changhua; Zhu, Qi

    2015-01-01

    A dual-cavity TM 02 –TM 01 mode converter is designed for a dual-mode operation over-moded relativistic backward-wave oscillator. With the converter, the fundamental mode output is achieved. Particle-in-cell simulation shows that the efficiency of beam-wave conversion was over 46% and a pureTM 01 mode output was obtained. Effects of end reflection provided by the mode converter were studied. Adequate TM 01 mode feedback provided by the converter enhances conversion efficiency. The distance between the mode converter and extraction cavity critically affect the generation of microwaves depending on the reflection phase of TM 01 mode feedback

  17. Observations on resistive wall modes

    International Nuclear Information System (INIS)

    Gerwin, R.A.; Finn, J.M.

    1996-01-01

    Several results on resistive wall modes and their application to tokamaks are presented. First, it is observed that in the presence of collisional parallel dynamics there is an exact cancellation to lowest order of the dissipative and sound wave effects for an ideal Ohm's law. This is easily traced to the fact that the parallel dynamics occurs along the perturbed magnetic field lines for such electromagnetic modes. Such a cancellation does not occur in the resistive layer of a tearing-like mode. The relevance to models for resistive wall modes using an electrostatic Hammett-Perkins type operator to model Landau damping will be discussed. Second, we observe that with an ideal Ohm's law, resistive wall modes can be destabilized by rotation in that part of parameter space in which the ideal MHD modes are stable with the wall at infinity. This effect can easily be explained by interpreting the resistive wall instability in terms of mode coupling between the backward stable MHD mode and a stable mode locked into the wall. Such an effect can occur for very small rotation for tearing-resistive wall modes in which inertia dominates viscosity in the layer, but the mode is stabilized by further rotation. For modes for which viscosity dominates in the layer, rotation is purely stabilizing. For both tearing models, a somewhat higher rotation frequency gives stability essentially whenever the tearing mode is stable with a perfectly conducting wall. These tearing/resistive wall results axe also simply explained in terms of mode coupling. It has been shown that resonant external ideal modes can be stabilized in the presence of resistive wall and resistive plasma with rotation of order the nominal tearing mode growth rate. We show that these modes behave as resistive wall tearing modes in the sense above. This strengthens the suggestion that rotational stabilization of the external kink with a resistive wall is due to the presence of resistive layers, even for ideal modes

  18. Using the incidence and impact of behavioural conditions in guide dogs to investigate patterns in undesirable behaviour in dogs

    OpenAIRE

    Caron-Lormier, Geoffrey; Harvey, Naomi D.; England, Gary C.W.; Asher, Lucy

    2016-01-01

    The domestic dog is one of our most popular companions and longest relationships, occupying different roles, from pet to working guide dog for the blind. As dogs age different behavioural issues occur and in some cases dogs may be relinquished or removed from their working service. Here we analyse a dataset on working guide dogs that were removed from their service between 1994 and 2013. We use the withdrawal reasons as a proxy for the manifestation of undesirable behaviour. More than 7,500 d...

  19. Single-frequency operation of a broad-area laser diode by injection locking of a complex spatial mode via a double phase conjugate mirror

    NARCIS (Netherlands)

    van Voorst, P.D.; Offerhaus, Herman L.; Boller, Klaus J.

    2006-01-01

    We demonstrate what is believed to be the first phase-coherent locking of a high-power broad-area diode to a single-frequency master laser. We use photorefractive double phase conjugation to lock the diode in a selfoptimized complex spatial mode while the photorefractive crystal diffracts that

  20. Mode decomposition evolution equations.

    Science.gov (United States)

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2012-03-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be

  1. Life-as-Lived Today: Perpetual (Undesired Liminality of the Half-widows of Kashmir

    Directory of Open Access Journals (Sweden)

    Paul DSouza

    2016-04-01

    Full Text Available According to Victor Turner, all liminality must eventually dissolve, for it is a state of great intensity that cannot exist very long without some sort of structure to sta-bilize it. This paper takes his lead and attempts to describe the liminal status of those women, the whereabouts of whose husbands are not known (they are locally re-ferred to as 'half-widows' in the conflict zone of Kashmir, India. The article ex-amines the concept of liminality based on life as lived today by these half-widows and shows how the effects of liminality operate in their day to day life, making them extremely vulnerable victims. In this, it is an attempt to expand upon the concept of liminality, originally linked almost exclusively to rites of passage. Furthermore, this paper reflects on the idea of permanent liminality that has been elaborated by soci-ologist Arpad Szakolczai. The narratives of the half-widows of Kashmir provide an example of how they are trapped in a form of 1permanent liminality1 far beyond what was initially defined as a 'temporal state'.

  2. A dosimetric system for the evaluation of undesired neutron dose in radiotherapy treatments with protons: experimental method and MC simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, A. [INFN, Torino (Italy); Fasolo, F.; Ongaro, C.; Durisi, E. [Torino Univ., Torino (Italy). Dipartimento di Fisica Sperimentale; Nastasi, U. [Ospedale S. Giovanni, Torino (Italy); Scielzo, G.; Fabris, M. [IRCC, Candiolo (Italy); Burn, K.W. [ENEA ERGSPIEC, Bologna (Italy)

    2002-07-01

    Linear accelerator is nowadays the most used radiotherapy device to treat tumour disease. In a number of cases secondary malignancies, due to the undesired dose delivered to the patient, could arise. The optimization of radiotherapy treatment can be obtained only through an accurate evaluation of the undesired dose. A method is presented to evaluate the photoneutron dose produced by GDR during cancer radiotherapy with energetic proton beams. It consists of a computer simulation code based on MCNP4B, in which the new routine GAMMAN was implemented, for the accurate study of photoneutron production in high Z and low Z elements. An experimental technique, based on a bubble passive spectrometer, allows direct measurements of photoneutron spectra at the patient plane, also inside the treatment zone. For the evaluation of neutron contribution to the dose at clinical organs, a new anthropomorphic phantom has been designed and realized, following ICRP60 recommendations. The results are presented for medical accelerators, equipped both with traditional collimator system and with multi leaf collimators.

  3. 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

    In this paper, a high performance fully digital peak current mode controller for DC-DC converters which supports the full duty cycle range from 0-100% is presented. Support for low duty cycle is very important during short circuit or converter overload and support for high duty cycle is important...... for faster response during a transient and for providing a larger output voltage range. The digital current controller is based on a new method, which estimates the inductor current in the middle of the falling current slope. The estimated inductor current is based on sampling the inductor current in either...... duty cycle range of 0-100%. The experimental results furthermore demonstrate the achievement of a very fast digital controller with a crossover frequency about 1/10 of the switching frequency, which is comparable to that obtained by analog peak current mode control....

  4. Design of durability test protocol for vehicular fuel cell systems operated in power-follow mode based on statistical results of on-road data

    Science.gov (United States)

    Xu, Liangfei; Reimer, Uwe; Li, Jianqiu; Huang, Haiyan; Hu, Zunyan; Jiang, Hongliang; Janßen, Holger; Ouyang, Minggao; Lehnert, Werner

    2018-02-01

    City buses using polymer electrolyte membrane (PEM) fuel cells are considered to be the most likely fuel cell vehicles to be commercialized in China. The technical specifications of the fuel cell systems (FCSs) these buses are equipped with will differ based on the powertrain configurations and vehicle control strategies, but can generally be classified into the power-follow and soft-run modes. Each mode imposes different levels of electrochemical stress on the fuel cells. Evaluating the aging behavior of fuel cell stacks under the conditions encountered in fuel cell buses requires new durability test protocols based on statistical results obtained during actual driving tests. In this study, we propose a systematic design method for fuel cell durability test protocols that correspond to the power-follow mode based on three parameters for different fuel cell load ranges. The powertrain configurations and control strategy are described herein, followed by a presentation of the statistical data for the duty cycles of FCSs in one city bus in the demonstration project. Assessment protocols are presented based on the statistical results using mathematical optimization methods, and are compared to existing protocols with respect to common factors, such as time at open circuit voltage and root-mean-square power.

  5. Microgeneration of electricity with producer gas in dual fuel mode operation; Microgeracao de eletricidade com gas de gaseificacao num motor gerador dual

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcelo J.; Souza, Samuel N.M. de; Souza, Abel A.; Secco, Deonir [Programa de Pos Graduacao em Energia na Agricultura - UNIOESTE, Cascavel, PR (Brazil)], e-mail: samuel.souza@unioeste.br; Ricieri, Reinaldo P. [Engenharia Agricola - UNIOESTE, Cascavel, PR (Brazil)

    2011-09-15

    Among the alternatives to meet the increasing of world demand for energy, the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a technological process of biomass energy production of a gaseous bio fuel. The fuel gas has a low calorific value that can be used in Diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil Diesel an engine generator, using gas from gasification of wood. The engine generator brand used was a BRANCO, with direct injection power of 7.36 k W (10 HP) coupled to an electric generator 5.5 k W. Diesel oil mixed with intake air was injected, as the oil was injected via an injector of the engine (dual mode). The fuel gas was produced in a down draft gasifier. The engine generator was put on load system from 0.5 k W to 3.5 k W through a set of electrical resistances. Diesel oil consumption was measured with a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood decreased Diesel consumption by up to 57%. (author)

  6. Evaluation of input output efficiency of oil field considering undesirable output —A case study of sandstone reservoir in Xinjiang oilfield

    Science.gov (United States)

    Zhang, Shuying; Wu, Xuquan; Li, Deshan; Xu, Yadong; Song, Shulin

    2017-06-01

    Based on the input and output data of sandstone reservoir in Xinjiang oilfield, the SBM-Undesirable model is used to study the technical efficiency of each block. Results show that: the model of SBM-undesirable to evaluate its efficiency and to avoid defects caused by traditional DEA model radial angle, improve the accuracy of the efficiency evaluation. by analyzing the projection of the oil blocks, we find that each block is in the negative external effects of input redundancy and output deficiency benefit and undesirable output, and there are greater differences in the production efficiency of each block; the way to improve the input-output efficiency of oilfield is to optimize the allocation of resources, reduce the undesirable output and increase the expected output.

  7. Negative symbolic aspects in destination branding: exploring the role of the 'undesired self' on web-based vacation information search intentions among potential first-time visitors

    OpenAIRE

    Bosnjak, Michael

    2010-01-01

    Tourist destination choices depend, among other factors, on the match between the destination’s personality image and consumers’ self-concept, in line with self-image congruence theory. Motives also mediate this relationship, yet tourism research largely neglects the influence of avoidance motives. This study applies the product-based construct of undesired congruity, or consumers’ tendency to avoid undesired stereotypical images, to the context of web-based vacation destination information s...

  8. Nanofluids and chemical highly retentive hydrogels for controlled and selective removal of overpaintings and undesired graffiti from street art.

    Science.gov (United States)

    Giorgi, Rodorico; Baglioni, Michele; Baglioni, Piero

    2017-06-01

    One of the main problems connected to the conservation of street art is the selective removal of overlying undesired graffiti, i.e., drawings and tags. Unfortunately, selective and controlled removal of graffiti and overpaintings from street art is almost unachievable using traditional methodologies. Recently, the use of nanofluids confined in highly retentive pHEMA/PVP semi-interpenetrated polymer networks was proposed. Here, we report on the selective removal of acrylic overpaintings from a layer of acrylic paint on mortar mockups in laboratory tests. The results of the cleaning tests were characterized by visual and photographic observation, optical microscopy, and FT-IR microreflectance investigation. It was shown that this methodology represents a major advancement with respect to the use of nonconfined neat solvents.

  9. Rapid detection of undesired cosmetic ingredients by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Ouyang, Jie; An, Dongli; Chen, Tengteng; Lin, Zhiwei

    2017-10-01

    In recent years, cosmetic industry profits soared due to the widespread use of cosmetics, which resulted in illicit manufacturers and products of poor quality. Therefore, the rapid and accurate detection of the composition of cosmetics has become crucial. At present, numerous methods, such as gas chromatography and liquid chromatography-mass spectrometry, were available for the analysis of cosmetic ingredients. However, these methods present several limitations, such as failure to perform comprehensive and rapid analysis of the samples. Compared with other techniques, matrix-assisted laser desorption ionization time-of-flight mass spectrometry offered the advantages of wide detection range, fast speed and high accuracy. In this article, we briefly summarized how to select a suitable matrix and adjust the appropriate laser energy. We also discussed the rapid identification of undesired ingredients, focusing on antibiotics and hormones in cosmetics.

  10. Diamagnetic composite material structure for reducing undesired electromagnetic interference and eddy currents in dielectric wall accelerators and other devices

    Science.gov (United States)

    Caporaso, George J.; Poole, Brian R.; Hawkins, Steven A.

    2015-06-30

    The devices, systems and techniques disclosed here can be used to reduce undesired effects by magnetic field induced eddy currents based on a diamagnetic composite material structure including diamagnetic composite sheets that are separated from one another to provide a high impedance composite material structure. In some implementations, each diamagnetic composite sheet includes patterned conductor layers are separated by a dielectric material and each patterned conductor layer includes voids and conductor areas. The voids in the patterned conductor layers of each diamagnetic composite sheet are arranged to be displaced in position from one patterned conductor layer to an adjacent patterned conductor layer while conductor areas of the patterned conductor layers collectively form a contiguous conductor structure in each diamagnetic composite sheet to prevent penetration by a magnetic field.

  11. Commissioning and operation of 130 kV/130 A switched-mode HV power supplies with the upgraded JET neutral beam injectors

    International Nuclear Information System (INIS)

    Edwards, D.C.; Bigi, M.; Brown, D.P.D.; Ganuza, D.; Garcia, F.; Hudson, Z.; Jones, T.T.C.; Perez, A.

    2005-01-01

    The design features, on-site testing, commissioning and operation are described of two new 130 kV/130 A HV power supply units serving four upgraded 130 kV/60 A positive ion neutral injectors (PINIs) on JET. Both units were factory tested at full power and pulse length into dummy resistive load. Following on-site installation, the factory tests were repeated. The transition from dummy-load testing to PINI operation required full integration of the HVPS within the overall JET control system, and rigorous testing of the co-ordinated actions and protections of all PINI power supplies (filament and arc for plasma source and negative suppression grid). The implementation of these functions is described. Extensive use was made of parasitic integrated test pulses, where the other PINIs could be operated normally, with the HVPS energised under full remote control together with the corresponding PINI plasma sources, but with the HVPS connected to dummy load. The amount of NB operation time dedicated to commissioning was thereby minimised, yet gave a high degree of confidence of readiness for HV energisation of the PINI, and first beam operation followed less than 24 h from HV connection to the PINI. The routine operating experience and performance, including load protection characteristics of the new HVPS units are also described

  12. Failure Modes

    DEFF Research Database (Denmark)

    Jakobsen, K. P.; Burcharth, H. F.; Ibsen, Lars Bo

    1999-01-01

    The present appendix contains the derivation of ten different limit state equations divided on three different failure modes. Five of the limit state equations can be used independently of the characteristics of the subsoil, whereas the remaining five can be used for either drained or undrained...

  13. undesirability , wit h relevance

    African Journals Online (AJOL)

    banzi

    disciplined environment; they were housed, fed, clothed and gainfully employed. The dissolution of the English monasteries in the late 15th century resulted in the vagrancy problem. This early example of kleptocracy had major social repercussions and led to parliament passing the Poor Laws (vide infra). The feudal system.

  14. An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures.

    Science.gov (United States)

    Bergquist, Leah; Zhang, Cuiyu; Ribeiro de Almeida, Roberta R; Pellegrene, Brittany; Salamonczyk, Miroslaw; Kim, Matthew; Hwang, Jung-Im; Kim, Kyeong-Jin; Lee, Joun-Ho; Jákli, Antal; Hegmann, Torsten

    2017-04-01

    We report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC a P A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterized and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.

  15. Preliminary Electrochemical Characterization of Anode Supported Solid Oxide Cell (AS-SOC) Produced in the Institute of Power Engineering Operated in Electrolysis Mode (SOEC)

    Science.gov (United States)

    Kupecki, Jakub; Motyliński, Konrad; Skrzypkiewicz, Marek; Wierzbicki, Michał; Naumovich, Yevgeniy

    2017-12-01

    The article discusses the operation of solid oxide electrochemical cells (SOC) developed in the Institute of Power Engineering as prospective key components of power-to-gas systems. The fundamentals of the solid oxide cells operated as fuel cells (SOFC - solid oxide fuel cells) and electrolysers (SOEC - solid oxide fuel cells) are given. The experimental technique used for electrochemical characterization of cells is presented. The results obtained for planar cell with anodic support are given and discussed. Based on the results, the applicability of the cells in power-to-gas systems (P2G) is evaluated.

  16. TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

    Energy Technology Data Exchange (ETDEWEB)

    R. C. O' Brien; J. E. O' Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

    2011-11-01

    A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

  17. Performance of an auto refrigerant cascade refrigerator operating in gas refrigerant supply (GRS) mode with nitrogen-hydrocarbon and argon-hydrocarbon refrigerants

    Science.gov (United States)

    Gurudath Nayak, H.; Venkatarathnam, G.

    2009-07-01

    There is a worldwide interest in the development of auto refrigerant cascade (ARC) refrigerators operating with refrigerant mixtures. Both flammable and non-flammable refrigerant mixtures can be used in these systems. The performance of an ARC system with optimum nitrogen-hydrocarbon and argon-hydrocarbon mixtures between 90 and 160 K is presented in this paper.

  18. Experience from development and operation of the core surveillance systems SCORPIO

    International Nuclear Information System (INIS)

    Berg, O.; Porsmyr, J.; Adlandsvik, K.A.

    1994-01-01

    The main motivation behind the development of SCORPIO is to make a practical tool for reactor operators which can increase the quality and quantity of information presented on core status and dynamic behaviour. This can first of all improve plant safety as undesired core conditions are detected and prevented. Secondly, more flexible and efficient plant operation is made possible. These improvements are obtained by better surveillance of core instrumentation and through detailed calculations of core behaviour using on-line simulators. The SCORPIO system has two parallel modes of operation: the Core Follow Mode and the Predictive Mode. The system has been in operation at the Ringhals PWR unit 2 in Sweden since the end of 1987 where it runs on Norsk Data mini-computers. Recently, there has been a renewed interest for SCORPIO mainly determined by the utilities' desire to obtain more economical and flexible plant operation. The SCORPIO system has been transferred to Unix based workstations and integrated with the Picasso-2 graphics system. In addition to Ringhals the new system is currently being installed at Nuclear Electri's Sizewell B PWR in UK and Duke Power's Catawba Unit 1,2 and McGuire Unit 1,2, USA. (author). 7 refs, 5 figs

  19. Transition between grid-connected mode and islanded mode in VSI ...

    Indian Academy of Sciences (India)

    Dibakar Das

    Abstract. This paper investigates the behaviour of a microgrid system during transition between grid-con- nected mode and islanded mode of operation. During the grid-connected mode the microgrid sources will be controlled to provide constant real and reactive power injection. During the islanded mode the sources will ...

  20. FPGA-based photon-counting phase-modulation fluorometer and a brief comparison with that operated in a pulsed-excitation mode

    Science.gov (United States)

    Iwata, Tetsuo; Taga, Takanori; Mizuno, Takahiko

    2018-02-01

    We have constructed a high-efficiency, photon-counting phase-modulation fluorometer (PC-PMF) using a field-programmable gate array, which is a modified version of the photon-counting fluorometer (PCF) that works in a pulsed-excitation mode (Iwata and Mizuno in Meas Sci Technol 28:075501, 2017). The common working principle for both is the simultaneous detection of the photoelectron pulse train, which covers 64 ns with a 1.0-ns resolution time (1.0 ns/channel). The signal-gathering efficiency was improved more than 100 times over that of conventional time-correlated single-photon-counting at the expense of resolution time depending on the number of channels. The system dead time for building a histogram was eliminated, markedly shortening the measurement time for fluorescent samples with moderately high quantum yields. We describe the PC-PMF and make a brief comparison with the pulsed-excitation PCF in precision, demonstrating the potential advantage of PC-PMF.

  1. Children's Perceptions of Hypothetical Peers With Undesirable Characteristics: Role of the Peers' Desire to Change, Source of Effort to Change, and Outcome.

    Science.gov (United States)

    Barnett, Mark A; Sonnentag, Tammy L; Wadian, Taylor W; Jones, Tucker L; Langley, Courtney A

    2015-01-01

    The present study, involving sixth- to eighth-grade students, is an extension of a prior investigation (Barnett, Livengood, Sonnentag, Barlett, & Witham, 2010) that examined children's perceptions of hypothetical peers with various undesirable characteristics. Results indicate that children's perceptions of hypothetical peers with an undesirable characteristic are influenced by the peers' desire to change, the source of effort to change, and the peers' success or failure in changing the characteristic. The children anticipated responding more favorably to peers who were successful in overcoming an undesirable characteristic than peers who were unsuccessful. Regardless of the peers' outcome, the children anticipated responding more favorably to peers who tried to change than peers who relied on the effort of adult authorities to motivate change. The children perceived successful peers as experiencing more positive affect than their unsuccessful counterparts, especially if the success was presented as a fulfillment of the peers' desire to change their undesirable characteristic. Finally, the children's ratings reflected the belief that, among peers who failed to change their undesirable characteristic, lacking the desire to change increases the relative likelihood that the characteristic will be permanent.

  2. Refugee Operations: Cultures in Conflict.

    Science.gov (United States)

    1982-12-01

    Lack of control over interpreters’ duties (I,F) Sexual obsession with female workers (F,M) Entire operation was a "human disaster (M) Undesirable...LITERATURE REVIEW -------------------------------- 17 A. EDWARD SAPIR --------------------------------- 17 B. SIGMUND FREUD ... Sexual Misconduct-------------------------49 2. Arson ------------------------------------ 50 3. Theft-------------------------------------50 4. Self

  3. Study of different operational modes of the IAP 2-port-DOAS instrument for atmospheric trace gases investigation during CINDI-2 campaign basing on residual noise analysis

    Science.gov (United States)

    Borovski, A.; Postylyakov, O.; Elokhov, A.; Bruchkovski, I.

    2017-11-01

    An instrument for measuring atmospheric trace gases by DOAS method using scattered solar radiation was developed in A.M.Obukhov IAP RAS. The instrument layout is based on the lab Shamrock 303i spectrograph supplemented by 2-port radiation input system employing optical fiber. Optical ports may be used with a telescope with fixed field of view or with a scanning MAX-DOAS unit. MAX-DOAS unit port will be used for investigation of gas contents and profiles in the low troposphere. In September 2016 the IAP instrument participated in the CINDI-2 campaign, held in the Netherlands. CINDI 2 (2nd Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments) involves about 40 instruments quasi-synchronously performing DOAS measurements of NO2 and other trace gases. During the campaign the instrument ports had telescopes A and B with similar field of view of about 0.3°. Telescope A was always directed to the zenith. Telescope B was directed at 5° elevation angle. Two gratings were installed in the spectrometer. They provide different spectral resolution (FWHM 0.4 and 0.8 nm respectively) and spectral window width ( 70 and 140 nm respectively). During CINDI-2 campaign we performed test measurements in UV and visible wavelength ranges to investigate instrument stability and retrieval errors of NO2 and HCHO contents. We perform the preliminary error analysis of retrieval of the NO2 and HCHO differential slant column densities using spectra measured in four modes of the instrument basing on residual noise analysis in this paper. It was found that rotation of grating turret does not significantly affected on quality of NO2 DSCD retrieval from spectra which measured in visible spectral region. Influence of grating turret rotation is much more significant for gas DSCD retrieval from spectra which measured in UV spectral region. Standard deviation of retrieval error points to presence of some systematic error.

  4. Using the incidence and impact of behavioural conditions in guide dogs to investigate patterns in undesirable behaviour in dogs.

    Science.gov (United States)

    Caron-Lormier, Geoffrey; Harvey, Naomi D; England, Gary C W; Asher, Lucy

    2016-04-14

    The domestic dog is one of our most popular companions and longest relationships, occupying different roles, from pet to working guide dog for the blind. As dogs age different behavioural issues occur and in some cases dogs may be relinquished or removed from their working service. Here we analyse a dataset on working guide dogs that were removed from their service between 1994 and 2013. We use the withdrawal reasons as a proxy for the manifestation of undesirable behaviour. More than 7,500 dogs were in the dataset used, 83% of which were retired (due to old age) and 17% were withdrawn for behavioural issues. We found that the main reasons for behaviour withdrawal were environmental anxiety, training, and fear/aggression. Breed and sex had an effect on the odds of dogs being withdrawn under the different reasons. The age at withdrawal for the different withdrawal reasons suggested that dogs were more likely to develop fear/aggression related issues early on, whilst issues related to training could develop at almost any age. We found no evidence for heterosis effecting behaviour. We believe that this work is relevant to the pet dog population and had implications for understanding ageing and genetic influences on behaviour.

  5. Children's disengagement from cancer care and treatment on the ward: an undesirable social tactic in the long term.

    Science.gov (United States)

    Løvschal-Nielsen, P; Clausen, N; Meinert, L

    2017-11-01

    This anthropological study explores children's non-social reactions during the active treatment period, the on-treatment, in a paediatric oncology ward in a Danish university hospital. It is argued that, although some children's non-social reactions is a tactical disengagement to manage the on-treatment situation, such non-social tactics might ultimately prove an undesirable strategy with negative long-term social consequences for social survivorship. Data were generated over 7 months of ethnographic fieldwork between May 2011 and January 2013, using qualitative methods such as participant observation and open-ended interviewing. Fifty children of both sexes between 4 and 15 years, their families and hospital staff participated in the study. These data formed the basis for the study. The findings show that children's response to care challenges, including exhaustion from care management, exposure from being in a public space, and the open-ended duration of treatment, configure in tactic forms that we term social disengagement. It is suggested that such tactical social disengagement might expand into long-term social patterns, and, as such, change from an alleviating tactic to a socially isolating and damaging tactic for survivors of cancer in childhood. © 2016 John Wiley & Sons Ltd.

  6. Potential conflict between TRIPS and GATT concerning parallel importation of drugs and possible solution to prevent undesirable market segmentation.

    Science.gov (United States)

    Lo, Chang-Fa

    2011-01-01

    From international perspective, parallel importation, especially with respect to drugs, has to do with the exhaustion principle in Article 6 of the TRIPS Agreement and the general exception in Article XX of the GATT 1994. Issues concerning the TRIPS Agreement have been constant topics of discussion. However, parallel importation in relation to the general rules of the GATT 1994 as well as to its exceptions provided in Article XX was not seriously discussed. In the view of the paper, there is a conflict between the provisions in these two agreements. The paper explains such conflict and tries to propose a method of interpretation to resolve the conflict between GATT Article XX and TRIPS Article 6 concerning parallel importation for the purpose of reducing the possible undesirable market segmentation in pharmaceutical sector. The method suggested in the paper is a proper application of good faith principle in the Vienna Convention to interpret GATT Article XX, so that there could be some flexibility for those prohibitions of parallel importation which have positive effect on international trade.

  7. A dark-field microscope for background-free detection of resonance fluorescence from single semiconductor quantum dots operating in a set-and-forget mode.

    Science.gov (United States)

    Kuhlmann, Andreas V; Houel, Julien; Brunner, Daniel; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D; Warburton, Richard J

    2013-07-01

    Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between resonance fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the resonance fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 10(7) and background-free detection of resonance fluorescence. The same optical setup operates over the entire quantum dot emission range (920-980 nm) and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical designs of the microscope are presented, as well as exemplary resonance fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance.

  8. Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

    Directory of Open Access Journals (Sweden)

    Samer Darwich

    2011-02-01

    Full Text Available One key component in the assembly of nanoparticles is their precise positioning to enable the creation of new complex nano-objects. Controlling the nanoscale interactions is crucial for the prediction and understanding of the behaviour of nanoparticles (NPs during their assembly. In the present work, we have manipulated bare and functionalized gold nanoparticles on flat and patterned silicon and silicon coated substrates with dynamic atomic force microscopy (AFM. Under ambient conditions, the particles adhere to silicon until a critical drive amplitude is reached by oscillations of the probing tip. Beyond that threshold, the particles start to follow different directions, depending on their geometry, size and adhesion to the substrate. Higher and respectively, lower mobility was observed when the gold particles were coated with methyl (–CH3 and hydroxyl (–OH terminated thiol groups. This major result suggests that the adhesion of the particles to the substrate is strongly reduced by the presence of hydrophobic interfaces. The influence of critical parameters on the manipulation was investigated and discussed viz. the shape, size and grafting of the NPs, as well as the surface chemistry and the patterning of the substrate, and finally the operating conditions (temperature, humidity and scan velocity. Whereas the operating conditions and substrate structure are shown to have a strong effect on the mobility of the particles, we did not find any differences when manipulating ordered vs random distributed particles.

  9. A dark-field microscope for background-free detection of resonance fluorescence from single semiconductor quantum dots operating in a set-and-forget mode

    International Nuclear Information System (INIS)

    Kuhlmann, Andreas V.; Houel, Julien; Warburton, Richard J.; Brunner, Daniel; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.

    2013-01-01

    Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between resonance fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the resonance fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 10 7 and background-free detection of resonance fluorescence. The same optical setup operates over the entire quantum dot emission range (920–980 nm) and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical designs of the microscope are presented, as well as exemplary resonance fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance

  10. A dark-field microscope for background-free detection of resonance fluorescence from single semiconductor quantum dots operating in a set-and-forget mode

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlmann, Andreas V.; Houel, Julien; Warburton, Richard J. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Brunner, Daniel [Instituto de Física Interdisciplinar y Sistemas Complejos, IFISC (CSIC-UIB), Campus Universitat Illes Balears, E-07122 Palma de Mallorca (Spain); Ludwig, Arne [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Reuter, Dirk [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Department Physik, Universität Paderborn, Warburger Strasse 100, D-33098 Paderborn (Germany); Wieck, Andreas D. [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2013-07-15

    Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between resonance fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the resonance fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 10{sup 7} and background-free detection of resonance fluorescence. The same optical setup operates over the entire quantum dot emission range (920–980 nm) and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical designs of the microscope are presented, as well as exemplary resonance fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance.

  11. Evaluation of the extended radical operation and intraoperative radiation therapy for the cancer of the head of the pancreas. Aspects of mode of extension and recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Imaizumi, Toshihide; Nakasako, Toshiaki; Harada, Nobuhiko; Hatori, Takashi; Fukuda, Akira; Munakata, Shigeru; Ozawa, Fumiaki; Hanyu, Fujio (Tokyo Women' s Medical Coll. (Japan))

    1994-10-01

    During the past 26 years, we have resected 282 ductal adenocarcinomas of the head pancreas. Ninety-three percent of the cases showed invasion to the extra-pancreatic tissues, and 86% were in stage III or IV. Curability by extended radical surgery was increased to 49% from 26% by the standard operation. Postoperative morbidity and mortality were 19% and 4%. One, 3- and 5-year-old survival rates were 44%, 13% and 9%, respectively. Five-year-survivors included 10 patients curatively resected by the extended radical surgery. The extended radical surgery was significant in improving survival time. The site of recurrence was the retroperitoneum in 63% of cases and the liver in 46%. Since 1988 we have selected the indications for extended radical surgery by using the preoperative diagnostic techniques. The patients who have severe invasion to the major vessels and/or retroperitoneum are not indicated for extended radical surgery. Intraoperative radiation therapy (IORT) for patients with resected ductal adenocarcinoma of the head of the pancreas was not so effective in terms of survival time and recurrence of the carcinoma in the protocol of the last 8 years. The selection of IORT is indicated for patients who are curatively resected by extended radical surgery. (author).

  12. Actions to ensure the power and utilities supplying during the start-up and regular operation of the TKCSA steel complex through island operation mode; Acoes para garantir o suprimento de energia eletrica e utilidades durante a fase de start up e de operacao regular do complexo siderurgico da TKCSA (Thyssenkrupp - Companhia Siderurgica do Atlantico) atraves do modo de operacao em ilha

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, Bernardo Matoso T.; Viana, Claudio Sobreira; Vaz, Daniel; Cesario, Fabricio; Pereira, Jose Antonio; Gimenez, Marcus Vinicius O.; Pascotto, Ricardo; Freitas Neto, Roberto Soares; Riederer, Werner [ThyssenKrupp Companhia Siderurgica do Atlantico (TKCSA), Rio de Janeiro, RJ (Brazil)

    2011-12-21

    At TKCSA, the energy and media distribution has an important function in the production processes. The electrical department is responsible for the power system operation, ensuring the receiving, transformation and supplying of this media for the regular and stable operation of the electrical equipment of the steel processes, and another important assignment of the electrical power sector is to guarantee the continuous power supply for the complex, even in case of interruption caused by the external grid, since the blast furnace, steel making and continuous casting cannot be interrupted abruptly. This continuous supply of energy is guaranteed by the Island Operation Mode (IOM), which always aims to ensure the supply of electricity from the Power Plant for the blowers, technical gases distribution system, fuel gases, steam and internal distribution of electricity and industrial water for the steel mill complex. During the complex start up and the regular operation phases, these two distribution systems (electricity and media) work interconnected and are kept in operation by the IOM, being guaranteed by the permanent operation of the electrical power generation system of Power Plant. This work presents how this concept was developed, tested and implemented at TKCSA. (author)

  13. A comparative analysis of China’s regional energy and emission performance: Which is the better way to deal with undesirable outputs?

    International Nuclear Information System (INIS)

    Wang Ke; Wei Yiming; Zhang Xian

    2012-01-01

    Measuring and improving the energy performance with considering emission constraints is an important issue for China’s energy conservation, pollutant emissions reduction and environment protection. This study utilizes several data envelopment analysis (DEA) based models to evaluate the total-factor energy and emission performance of China’s 30 regions within a joint production framework of considering desirable and undesirable outputs as well as separated energy and non-energy inputs. DEA window analysis is applied in this study to deal with cross-sectional and time-varying data, so as to measure the performance during the period of 2000–2009. Two treatments for undesirable outputs are combined with DEA models and the associated indicators for simplex energy performance and unified energy and emission performance measurement are proposed and compared. The evaluation results indicate that the treatment of undesirable outputs transformation is more appropriate for China’s regional energy and emission performance evaluation because it has stronger discriminating power and can provide more reasonable evaluation results that characterize China’s regions. The empirical result shows that east China has the highest and the most balanced energy and emission performance. The energy and emission performance of China remained stable during 2000–2003, decreased slightly during 2004–2006, and has continuously increased since 2007. - Highlights: ► We evaluate China’s regional energy and emission performance using DEA based models. ► We compare two undesirable outputs treatments according to the evaluation results. ► To treat undesirable outputs as inputs has weaker discriminating power in evaluation. ► Simplex energy performance, without environmental factors, is a biased evaluation. ► China’s energy and emission performance is approximately stable during study period.

  14. PLC-based mode multi/demultiplexers for mode division multiplexing

    Science.gov (United States)

    Saitoh, Kunimasa; Hanzawa, Nobutomo; Sakamoto, Taiji; Fujisawa, Takeshi; Yamashita, Yoko; Matsui, Takashi; Tsujikawa, Kyozo; Nakajima, Kazuhide

    2017-02-01

    Recently developed PLC-based mode multi/demultiplexers (MUX/DEMUXs) for mode division multiplexing (MDM) transmission are reviewed. We firstly show the operation principle and basic characteristics of PLC-based MUX/DEMUXs with an asymmetric directional coupler (ADC). We then demonstrate the 3-mode (2LP-mode) multiplexing of the LP01, LP11a, and LP11b modes by using fabricated PLC-based mode MUX/DEMUX on one chip. In order to excite LP11b mode in the same plane, a PLC-based LP11 mode rotator is introduced. Finally, we show the PLC-based 6-mode (4LP-mode) MUX/DEMUX with a uniform height by using ADCs, LP11 mode rotators, and tapered waveguides. It is shown that the LP21a mode can be excited from the LP11b mode by using ADC, and the two nearly degenerated LP21b and LP02 modes can be (de)multiplexed separately by using tapered mode converter from E13 (E31) mode to LP21b (LP02) mode.

  15. Depth of interaction and bias voltage depenence of the spectral response in a pixellated CdTe detector operating in time-over-threshold mode subjected to monochromatic X-rays

    Science.gov (United States)

    Fröjdh, E.; Fröjdh, C.; Gimenez, E. N.; Maneuski, D.; Marchal, J.; Norlin, B.; O'Shea, V.; Stewart, G.; Wilhelm, H.; Modh Zain, R.; Thungström, G.

    2012-03-01

    High stopping power is one of the most important figures of merit for X-ray detectors. CdTe is a promising material but suffers from: material defects, non-ideal charge transport and long range X-ray fluorescence. Those factors reduce the image quality and deteriorate spectral information. In this project we used a monochromatic pencil beam collimated through a 20μm pinhole to measure the detector spectral response in dependance on the depth of interaction. The sensor was a 1mm thick CdTe detector with a pixel pitch of 110μm, bump bonded to a Timepix readout chip operating in Time-Over-Threshold mode. The measurements were carried out at the Extreme Conditions beamline I15 of the Diamond Light Source. The beam was entering the sensor at an angle of \\texttildelow20 degrees to the surface and then passed through \\texttildelow25 pixels before leaving through the bottom of the sensor. The photon energy was tuned to 77keV giving a variation in the beam intensity of about three orders of magnitude along the beam path. Spectra in Time-over-Threshold (ToT) mode were recorded showing each individual interaction. The bias voltage was varied between -30V and -300V to investigate how the electric field affected the spectral information. For this setup it is worth noticing the large impact of fluorescence. At -300V the photo peak and escape peak are of similar height. For high bias voltages the spectra remains clear throughout the whole depth but for lower voltages as -50V, only the bottom part of the sensor carries spectral information. This is an effect of the low hole mobility and the longer range the electrons have to travel in a low field.

  16. Comparative performance studies of a 4-stroke CI engine operated on dual fuel mode with producer gas and Honge oil and its methyl ester (HOME) with and without carburetor

    Energy Technology Data Exchange (ETDEWEB)

    Banapurmath, N.R.; Tewari, P.G. [Department of Mechanical Engineering, B.V.B. College of Engineering and Technology, Poona Bangalore Road, Hubli, Karnataka 580031 (India)

    2009-04-15

    In order to meet the energy requirements, there has been growing interest in alternative fuels like biodiesels, methyl alcohol, ethyl alcohol, biogas, hydrogen and producer gas to provide a suitable diesel oil substitute for internal combustion engines. Biomass is basically composed of carbon, hydrogen and oxygen. A proximate analysis of biomass indicates the volatile matter to be between 60-80% and 20-25% carbon and the rest, ash. The first part of sub-stoichiometric oxidation leads to the loss of volatiles from biomass and is exothermic; it results in peak temperatures of 1400-1500 K and generation of gaseous products like carbon monoxide, hydrogen in some proportions and carbon dioxide and water vapor, which in turn are reduced in part to carbon monoxide and hydrogen by the hot bed of charcoal generated during the process of gasification. Therefore, solid biomass can be converted into a mixture of combustible gases, and subsequently utilized for combustion in a CI engine. Producer gas, if used in dual fuel mode, is an excellent substitute for reducing the amount of diesel consumed by the CI engine. Downdraft moving bed gasifiers coupled with an IC engine are a good choice for moderate quantities of available biomass, up to 500 kW of electric power. Vegetable oils present a very promising alternative to diesel oil since they are renewable and have similar properties. Vegetable oils offer almost the same power output with slightly lower thermal efficiency when used in diesel engines. Research in this direction with edible oils have yielded encouraging results, but their use as fuel for diesel engines has limited applications due to higher domestic requirement. In view of this, Honge oil (Pongamia Pinnata Linn) is selected and its viscosity is reduced by the transesterification process to obtain Honge oil methyl ester (HOME). Since vegetable oils produce higher smoke emissions, dual fuel operation could be adopted in order to improve their performance. A gas

  17. Operational modes of providing linkage between veterinary ...

    African Journals Online (AJOL)

    Findings of the study revealed that livestock farmers that had contacts with veterinary agents had higher rate of adoption; that the agents had preference for large scale/commercial farmers at the expense of small to medium scale farmers; and that the agents engaged more in vaccination of animals, supply of vaccines, drugs ...

  18. Predicting the Diversity of Foreign Entry Modes

    DEFF Research Database (Denmark)

    Hashai, Niron; Geisler Asmussen, Christian; Benito, Gabriel

    2007-01-01

    This paper expands entry mode literature by referring to multiple modes exerted in different value chain activities within and across host markets, rather than to a single entry mode at the host market level. Scale of operations and knowledge intensity are argued to affect firms' entry mode...... diversity across value chain activities and host markets. Analyzing a sample of Israeli based firms we show that larger firms exhibit a higher degree of entry mode diversity both across value chain activities and across host markets. Higher levels of knowledge intensity are also associated with more...

  19. Coupled-Mode Theory derivation of the formal equivalence between a three-mode waveguide and a set of three mutually coupled single-mode waveguides

    Directory of Open Access Journals (Sweden)

    Boucher Yann G.

    2017-01-01

    Full Text Available The formal identification between a two-mode waveguide and a system of two mutually coupled single-mode waveguides stems from the symmetries of the evolution operator. When the gap tends to zero, the super-modes of the coupled system merge continuously into the modes of the multimode waveguide. For modelling purposes, it is very tempting to extend the analogy to three-mode waveguides (and beyond. But not without some precautions…

  20. Soft mode of lead zirconate

    International Nuclear Information System (INIS)

    Pan'ko, G.F.; Prisedskij, V.V.; Klimov, V.V.

    1983-01-01

    Anisotropic diffusional scattering of electrons on PbZrO 3 crystal in the temperature range of phase transition has been recorded. As a result of its analysis it has been established that in lead zirconate the rotational vibrational mode G 25 plays the role of soft mode. The experiment is carried out using PbZrO 3 monocrystals in translucent electron microscope EhM-200, operating in the regime of microdiffraction at accelerating voltage of 150 kV and beam current 50 μA; sample preparation is realized using the method of shearing and fragmentation