WorldWideScience

Sample records for in-core test loop

  1. Testing loop quantum cosmology

    Science.gov (United States)

    Wilson-Ewing, Edward

    2017-03-01

    Loop quantum cosmology predicts that quantum gravity effects resolve the big-bang singularity and replace it by a cosmic bounce. Furthermore, loop quantum cosmology can also modify the form of primordial cosmological perturbations, for example by reducing power at large scales in inflationary models or by suppressing the tensor-to-scalar ratio in the matter bounce scenario; these two effects are potential observational tests for loop quantum cosmology. In this article, I review these predictions and others, and also briefly discuss three open problems in loop quantum cosmology: its relation to loop quantum gravity, the trans-Planckian problem, and a possible transition from a Lorentzian to a Euclidean space-time around the bounce point.

  2. Gas Test Loop Booster Fuel Hydraulic Testing

    Energy Technology Data Exchange (ETDEWEB)

    Gas Test Loop Hydraulic Testing Staff

    2006-09-01

    The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3.

  3. High Temperature Sodium Thermal Convection Test Loop

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A project for the evaluation of compatibility characteristic of structural materials used in China experimental fast reactor(CEFR) has been in operation. The conditions which these structural materials contact with liquid sodium in reactor can be simulated by the tests in high temperature sodium thermal convection test loop. The main aims of designing and constructing the thermal convection test loop is for the corrosion test of CEFR materials, and the objective is to obtain the corrosion data of domestic materials.The main features of the test loop are shown in Fig.1. The primary components of the loop

  4. Hardware-in-the-Loop Testing

    Data.gov (United States)

    Federal Laboratory Consortium — RTC has a suite of Hardware-in-the Loop facilities that include three operational facilities that provide performance assessment and production acceptance testing of...

  5. Design and Commissioning Test of WKN Sodium Thermodynamic Test Loop

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the research of fast reactor a sodium thermodynamic test loop was designed and commissioned. Its highest operating temperature is 700℃, after the sodium is passed the cooler, the temperature of the sodium can be reduced to 300 ℃; the sodium flow is 0.2 m3/h. The loop consists of sodium electromagnetic pump, sodium flow meter, two groups of heater, two groups of cooler, surge tank, sodium vapor trap, diffusion cold trap, sodium transportation tank, electric control panel and microprocessor. It has two experimental bypass loops for research of heat transfer

  6. In-core materials testing under LWR conditions in the Halden reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, P.J.; Hauso, E.; Hoegberg, N.W.; Karlsen, T.M.; McGrath, M.A. [OECD Halden Reactor Project (Norway)

    2002-07-01

    The Halden boiling water reactor (HBWR) has been in operation since 1958. It is a test reactor with a maximum power of 18 MW and is cooled and moderated by boiling heavy water, with a normal operating temperature of 230 C and a pressure of 34 bar. In the past 15 years increasing emphasis has been placed on materials testing, both of in-core structural materials and fuel claddings. These tests require representative light water reactor (LWR) conditions, which are achieved by housing the test rigs in pressure flasks that are positioned in fuel channels in the reactor and connected to dedicated water loops, in which boiling water reactor (BWR) or pressurised water reactor (PWR) conditions are simulated. Understanding of the in-core behaviour of fuel or reactor materials can be greatly improved by on-line measurements during power operation. The Halden Project has performed in-pile measurements for a period of over 35 years, beginning with fuel temperature measurements using thermocouples and use of differential transformers for measurement of fuel pellet or cladding dimensional changes and internal rod pressure. Experience gained over this period has been applied to on-line instrumentation for use in materials tests. This paper gives details of the systems used at Halden for materials testing under LWR conditions. The techniques used to provide on-line data are described and illustrative results are presented. (authors)

  7. Test of In-core Flux Detectors in KNK II

    CERN Document Server

    Hoppe, P

    1979-01-01

    The development of in-core detectors for Liquid Metal Fast Breeder Reactors (LMFBRs) is still in an early stage, and little operation experience is available. Therefore self-powered neutron and gamma detectors and neutron sensitive ionization chambers -especially developed for LMFBRs- have been tested in the Fast Sodium Cooled Test Reactor KNK II. Seven flux detectors have been installed in the core of KNK II by means of a special test rig. Five of them failed already within the first week during operation in the reactor. Due to measurements of electrical resistances and capacities, sodium penetrating into the detectors or cables probably seems to be the cause. As tests prior to the installation in the core proved the tightness of all detectors, it is suspected that small cracks have developed in the detector casings or in the outer cable sheaths during their exposure to the hot coolant. Two ionization chambers did not show these faults. However, one of them failed because the saturation current plateau disap...

  8. Cosmography in testing loop quantum gravity

    CERN Document Server

    Szydlowski, Marek; Stachowiak, Tomasz

    2007-01-01

    It was recently suggested by Martin Bojowald that quantum gravity effects give rise to new, potentially observable effects. We check whether this is the case for astronomical tests by trying to constrain the density parameters of the Friedmann equation with a $(-)(1+z)^6$ type of contribution. We describe different interpretations of such an additional term: geometric effects of Loop Quantum Cosmology, effects of braneworld cosmological models, non-standard cosmological models in metric-affine gravity, and models with spinning fluid. Kinematical (or geometrical) tests based on null geodesics are insufficient to separate individual matter components when they behave like perfect fluid and scale in the same way. Still, it is possible to measure their overall effect. We use recent measurements of the coordinate distances from Fanaroff-Riley type IIb (FRIIb) radio galaxy (RG) data, supernovae type Ia (SNIa) data, baryon oscillation peak and cosmic microwave background radiation (CMBR) observations to obtain stron...

  9. Stress Analysis and Calculation of Flow Interruption Capability Test Loop

    Institute of Scientific and Technical Information of China (English)

    FENG; Bo; QI; Xiao-guang; CHENG; Dao-xi

    2012-01-01

    <正>A stress-analysis and calculation has been done for the flow interruption capability test loop (Fig. 1). In the design condition, the test loop is operated on 350 ℃ and 20MPa. By reasonably simplifying and modeling, a stress-analysis program named Triflex was used to analyze the piping stress and optimize the piping supports, which meet the compliance. The work will provide the necessary basis for the construction of the loop and operation security.

  10. Conceptional design of test loop for FIV in fuel bundle

    Energy Technology Data Exchange (ETDEWEB)

    Sim, W. G.; Yang, J. S.; Kim, S. W. [Hannam Univ., Taejeon (Korea)

    2001-01-01

    It is urgent to develop the analytical model for the structural/mechanical integrity of fuel rod. In general, it is not easy to develop a pure analytical model. Occasionally, experimental results have been utilized for the model. Because of this reason, it is required to design proper test loop. Using the optimized test loop, with the optimized test loop, the dynamic behaviour of the rod will be evaluated and the critical flow velocity, which the rod loses the stability in, will be measured for the design of the rod. To verify the integrity of the fuel rod, it is required to evaluate the dynamic behaviour and the critical flow velocity with the test loop. The test results will be utilized to the design of the rod. Generally, the rod has a ground vibration due to turbulence in wide range of flow velocity and the amplitude of vibration becomes larger by the resonance, in a range of the velocity where occurs vortex. The rod loses stability in critical flow velocity caused by fluid-elastic instability. For the purpose of the present work to perform the conceptional design of the test loop, it is necessary (1) to understand the mechanism of the flow-induced vibration and the related experimental coefficients, (2) to evaluate the existing test loops for improving the loop with design parameters and (3) to decide the design specifications of the major equipments of the loop. 35 refs., 23 figs., 2 tabs. (Author)

  11. High Temperature Fluoride Salt Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cunningham, Richard Burns [Univ. of Tennessee, Knoxville, TN (United States); Fugate, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peretz, Fred J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    with 3 cm diameter graphite-based fuel pebbles slowly circulating up through the core. Molten salt coolant (FLiBe) at 700°C flows concurrently (at significantly higher velocity) with the pebbles and is used to remove heat generated in the reactor core (approximately 1280 W/pebble), and supply it to a power conversion system. Refueling equipment continuously sorts spent fuel pebbles and replaces spent or damaged pebbles with fresh fuel. By combining greater or fewer numbers of pebble channel assemblies, multiple reactor designs with varying power levels can be offered. The PB-AHTR design is discussed in detail in Reference [1] and is shown schematically in Fig. 1. Fig. 1. PB-AHTR concept (drawing taken from Peterson et al., Design and Development of the Modular PB-AHTR Proceedings of ICApp 08). Pebble behavior within the core is a key issue in proving the viability of this concept. This includes understanding the behavior of the pebbles thermally, hydraulically, and mechanically (quantifying pebble wear characteristics, flow channel wear, etc). The experiment being developed is an initial step in characterizing the pebble behavior under realistic PB-AHTR operating conditions. It focuses on thermal and hydraulic behavior of a static pebble bed using a convective salt loop to provide prototypic fluid conditions to the bed, and a unique inductive heating technique to provide prototypic heating in the pebbles. The facility design is sufficiently versatile to allow a variety of other experimentation to be performed in the future. The facility can accommodate testing of scaled reactor components or sub-components such as flow diodes, salt-to-salt heat exchangers, and improved pump designs as well as testing of refueling equipment, high temperature instrumentation, and other reactor core designs.

  12. Hardware-in-the-loop testing of marine control system

    Directory of Open Access Journals (Sweden)

    Roger Skjetne

    2006-10-01

    Full Text Available Hardware-in-the-Loop (HIL testing is proposed as a new methodology for verification and certification of marine control systems. Formalizing such testing necessitates the development of a vocabulary and set of definitions. This paper treats these issues by constructing a framework suitable for industrial HIL test applications and certification of marine systems.

  13. Hardware-in-the-loop testing of marine control system

    OpenAIRE

    2006-01-01

    Hardware-in-the-Loop (HIL) testing is proposed as a new methodology for verification and certification of marine control systems. Formalizing such testing necessitates the development of a vocabulary and set of definitions. This paper treats these issues by constructing a framework suitable for industrial HIL test applications and certification of marine systems.

  14. Operation of the nuclear fuel cycle test facilities -Operation of the hot test loop facilities

    Energy Technology Data Exchange (ETDEWEB)

    Chun, S. Y.; Jeong, M. K.; Park, C. K.; Yang, S. K.; Won, S. Y.; Song, C. H.; Jeon, H. K.; Jeong, H. J.; Cho, S.; Min, K. H.; Jeong, J. H.

    1997-01-01

    A performance and reliability of a advanced nuclear fuel and reactor newly designed should be verified by performing the thermal hydraulics tests. In thermal hydraulics research team, the thermal hydraulics tests associated with the development of an advanced nuclear fuel and reactor haven been carried out with the test facilities, such as the Hot Test Loop operated under high temperature and pressure conditions, Cold Test Loop, RCS Loop and B and C Loop. The objective of this project is to obtain the available experimental data and to develop the advanced measuring techniques through taking full advantage of the facilities. The facilities operated by the thermal hydraulics research team have been maintained and repaired in order to carry out the thermal hydraulics tests necessary for providing the available data. The performance tests for the double grid type bottom end piece which was improved on the debris filtering effectivity were performed using the PWR-Hot Test Loop. The CANDU-Hot Test Loop was operated to carry out the pressure drop tests and strength tests of CANFLEX fuel. The Cold Test Loop was used to obtain the local velocity data in subchannel within HANARO fuel bundle and to study a thermal mixing characteristic of PWR fuel bundle. RCS thermal hydraulic loop was constructed and the experiments have been carried out to measure the critical heat flux. In B and C Loop, the performance tests for each component were carried out. (author). 19 tabs., 78 figs., 19 refs.

  15. Operational Results of a Closed Brayton Cycle Test-Loop

    Science.gov (United States)

    Wright, Steven A.; Fuller, Robert; Lipinski, Ronald J.; Nichols, Kenneth; Brown, Nicholas

    2005-02-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kWth with a maximum outlet temperature of ˜1000 K.

  16. Smart Home Hardware-in-the-Loop Testing

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Annabelle

    2017-07-12

    This presentation provides a high-level overview of NREL's smart home hardware-in-the-loop testing. It was presented at the Fourth International Workshop on Grid Simulator Testing of Energy Systems and Wind Turbine Powertrains, held April 25-26, 2017, hosted by NREL and Clemson University at the Energy Systems Integration Facility in Golden, Colorado.

  17. OPEN-LOOP FOG SIGNAL TESTING AND WAVELET ELIMINATING NOISE

    Institute of Scientific and Technical Information of China (English)

    ZHUYun-zhao; WANGShun-ring; MIAOLing-juan; WANGBo

    2005-01-01

    An open-loop fiber optic gyro (FOG) testing system is designed. The noise characteristic of open-loop fiber optic gyro signals is analyzed. The wavelet eliminating noise method is discussed and compared with other methods, such as smoothing and low-pass filter methods. Results indicate that the wavelet eliminating noise method can satisfy the measuring demand of the FOG weak output signal with noise disturbing. The wavelet analysis method can efficiently eliminate the noise and reserve the information of the signal. The eliminating noise effect of using different wavelet base functions is compared. The effectiveness of multiresolution wavelet analyses of eliminating noise is proved by experimental results.

  18. Systematic Unit Testing in a Read-eval-print Loop

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2010-01-01

    Lisp programmers constantly carry out experiments in a read-eval-print loop.  The experimental activities convince the Lisp programmers that new or modified pieces of programs work as expected.  But the experiments typically do not represent systematic and comprehensive unit testing efforts...... how to use a test repository for other purposes than testing.  As a concrete contribution we show how to use test cases as examples in library interface documentation.  It is hypothesized---but not yet validated---that the tool will motivate the Lisp programmer to take the transition from casual...

  19. Systematic Unit Testing in a Read-eval-print Loop

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2010-01-01

    .  Rather, the experiments are quick and dirty one shot validations which do not add lasting value to the software, which is being developed.  In this paper we propose a tool that is able to collect, organize, and re-validate test cases, which are entered as expressions in a read-eval-print loop......Lisp programmers constantly carry out experiments in a read-eval-print loop.  The experimental activities convince the Lisp programmers that new or modified pieces of programs work as expected.  But the experiments typically do not represent systematic and comprehensive unit testing efforts.......  The process of collecting the expressions and their results imposes only little extra work on the programmer.  The use of the tool provides for creation of test repositories, and it is intended to catalyze a much more systematic approach to unit testing in a read-eval-print loop.  In the paper we also discuss...

  20. Mechanisms Engineering Test Loop - Phase 1 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Kultgen, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Hvasta, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lisowski, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Toter, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Borowski, A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    This report documents the current status of the Mechanisms Engineering Test Loop (METL) as of the end of FY2016. Currently, METL is in Phase I of its design and construction. Once operational, the METL facility will test small to intermediate-scale components and systems in order to develop advanced liquid metal technologies. Testing different components in METL is essential for the future of advanced fast reactors as it will provide invaluable performance data and reduce the risk of failures during plant operation.

  1. Hanford Tank Farms Waste Certification Flow Loop Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Bamberger, Judith A.; Meyer, Perry A.; Scott, Paul A.; Adkins, Harold E.; Wells, Beric E.; Blanchard, Jeremy; Denslow, Kayte M.; Greenwood, Margaret S.; Morgen, Gerald P.; Burns, Carolyn A.; Bontha, Jagannadha R.

    2010-01-01

    A future requirement of Hanford Tank Farm operations will involve transfer of wastes from double shell tanks to the Waste Treatment Plant. As the U.S. Department of Energy contractor for Tank Farm Operations, Washington River Protection Solutions anticipates the need to certify that waste transfers comply with contractual requirements. This test plan describes the approach for evaluating several instruments that have potential to detect the onset of flow stratification and critical suspension velocity. The testing will be conducted in an existing pipe loop in Pacific Northwest National Laboratory’s facility that is being modified to accommodate the testing of instruments over a range of simulated waste properties and flow conditions. The testing phases, test matrix and types of simulants needed and the range of testing conditions required to evaluate the instruments are described

  2. Loop corrections and a new test of inflation

    CERN Document Server

    Tasinato, Gianmassimo; Nurmi, Sami; Wands, David

    2013-01-01

    Inflation is the leading paradigm for explaining the origin of primordial density perturbations and the observed temperature fluctuations of the cosmic microwave background. However many open questions remain, in particular whether one or more scalar fields were present during inflation and how they contributed to the primordial density perturbation. We propose a new observational test of whether multiple fields, or only one (not necessarily the inflaton) generated the perturbations. We show that our test, relating the bispectrum and trispectrum, is protected against loop corrections at all orders, unlike previous relations.

  3. Design of Protection System for High Temperature and High Pressure Test Loop

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Ming-kui; XU; Qi-guo; JIA; Yu-wen

    2012-01-01

    <正>High temperature and high pressure test loop is a research platform of China Advanced Research Reactor (CARR). Dedicated protection system is designed for safety of test loop and the reactor. Postulated initiating event related to test loop operation is analyzed, thereafter, protection variables are determined. 3 independent redundant measure channels are designed for each protection variable

  4. Irradiation Testing Vehicles for Fast Reactors from Open Test Assemblies to Closed Loops

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Grandy, Christopher [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-15

    A review of irradiation testing vehicle approaches and designs that have been incorporated into past Sodium-Cooled Fast Reactors (SFRs) or envisioned for incorporation has been carried out. The objective is to understand the essential features of the approaches and designs so that they can inform test vehicle designs for a future U.S. Fast Test Reactor. Fast test reactor designs examined include EBR-II, FFTF, JOYO, BOR-60, PHÉNIX, JHR, and MBIR. Previous designers exhibited great ingenuity in overcoming design and operational challenges especially when the original reactor plant’s mission changed to an irradiation testing mission as in the EBRII reactor plant. The various irradiation testing vehicles can be categorized as: Uninstrumented open assemblies that fit into core locations; Instrumented open test assemblies that fit into special core locations; Self-contained closed loops; and External closed loops. A special emphasis is devoted to closed loops as they are regarded as a very desirable feature of a future U.S. Fast Test Reactor. Closed loops are an important technology for irradiation of fuels and materials in separate controlled environments. The impact of closed loops on the design of fast reactors is also discussed in this report.

  5. Molten Salt Test Loop (MSTL) system customer interface document.

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.; Briggs, Ronald D.

    2013-09-01

    The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL is a test capability that allows customers and researchers to test components in flowing, molten nitrate salt. The components tested can range from materials samples, to individual components such as flex hoses, ball joints, and valves, up to full solar collecting systems such as central receiver panels, parabolic troughs, or linear Fresnel systems. MSTL provides realistic conditions similar to a portion of a concentrating solar power facility. The facility currently uses 60/40 nitrate %E2%80%9Csolar salt%E2%80%9D and can circulate the salt at pressure up to 40 bar (600psi), temperature to 585%C2%B0C, and flow rate of 44-50kg/s(400-600GPM) depending on temperature. The purpose of this document is to provide a basis for customers to evaluate the applicability to their testing needs, and to provide an outline of expectations for conducting testing on MSTL. The document can serve as the basis for testing agreements including Work for Others (WFO) and Cooperative Research and Development Agreements (CRADA). While this document provides the basis for these agreements and describes some of the requirements for testing using MSTL and on the site at Sandia, the document is not sufficient by itself as a test agreement. The document, however, does provide customers with a uniform set of information to begin the test planning process.

  6. Preliminary Feasibility, Design, and Hazard Analysis of a Boiling Water Test Loop Within the Idaho National Laboratory Advanced Test Reactor National Scientific User Facility

    Energy Technology Data Exchange (ETDEWEB)

    Douglas M. Gerstner

    2009-05-01

    The Advanced Test Reactor (ATR) is a pressurized light-water reactor with a design thermal power of 250 MW. The principal function of the ATR is to provide a high neutron flux for testing reactor fuels and other materials. The ATR and its support facilities are located at the Idaho National Laboratory (INL). A Boiling Water Test Loop (BWTL) is being designed for one of the irradiation test positions within the. The objective of the new loop will be to simulate boiling water reactor (BWR) conditions to support clad corrosion and related reactor material testing. Further it will accommodate power ramping tests of candidate high burn-up fuels and fuel pins/rods for the commercial BWR utilities. The BWTL will be much like the pressurized water loops already in service in 5 of the 9 “flux traps” (region of enhanced neutron flux) in the ATR. The loop coolant will be isolated from the primary coolant system so that the loop’s temperature, pressure, flow rate, and water chemistry can be independently controlled. This paper presents the proposed general design of the in-core and auxiliary BWTL systems; the preliminary results of the neutronics and thermal hydraulics analyses; and the preliminary hazard analysis for safe normal and transient BWTL and ATR operation.

  7. Conceptual Design for a High-Temperature Gas Loop Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    James B. Kesseli

    2006-08-01

    This report documents an early-stage conceptual design for a high-temperature gas test loop. The objectives accomplished by the study include, (1) investigation of existing gas test loops to determine ther capabilities and how the proposed system might best complement them, (2) development of a preliminary test plan to help identify the performance characteristics required of the test unit, (3) development of test loop requirements, (4) development of a conceptual design including process flow sheet, mechanical layout, and equipment specifications and costs, and (5) development of a preliminary test loop safety plan.

  8. Impact of Looping on Middle School Science Standardized Achievement Tests

    Science.gov (United States)

    Barger, Tammy M.

    2013-01-01

    Looping may be defined as a teacher remaining with a group of students for multiple academic years. In this quantitative study, looping was examined as a factor on science achievement. State-wide eighth grade school level 2010 Pennsylvania System of School Assessment (PSSA) data were used. By responding to a mailing, school administrators…

  9. Pressure drop and blower performance tests in very high temperature Helium Experimental LooP (HELP)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Soo; Hong, Sung Deok; Kim, Yong Wan [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Korea Atomic Energy Research Institute (KAERI) has developed the gas loops to develop and verify the key components of the nuclear hydrogen production system. At the present, KAERI is operating a small scale gas loop for feasibility tests of process heat exchanger and a very high temperature Helium Experimental LooP (HELP) for verification tests of bench scale prototypes for high temperature key components in Very High Temperature gas cooled Reactor (VHTR). Figure 1 presents the HELP assembled with the key components. The size was designed for the verification test of a 150kW intermediate heat exchanger or the simulation test in a 1/6 scaled down fuel block. The loop consists of the primary loop and the secondary loop. The primary loop and the secondary loop simulate VHTR and intermediate loop in nuclear hydrogen production system, respectively. The loops were designed to withstand the maximum temperature of 1000 .Deg. C, the maximum pressure of 9.0 MPa, and the normal mass velocity of 0.5 kg/sec. The working fluid is helium as the actual coolant of VHTR. The primary loop is composed of a preheater, a high temperature heater, a hot gas duct, intermediate heat exchangers, a water cooled U tube heat exchanger, a gas bearing circulator, a passive venting system and gas filters. The secondary loop has the same system configuration as the primary loop except a high temperature heater. Two loops share a helium supply system, a helium purification system and the water loop for a cooling tower as Figure 2. In this study, the experimental results of the bypass line pressure drop and blower performance at the nitrogen condition are analyzed to predict the main line mass flow rates without heaters.

  10. Results from tests of TFL Hydragard sampling loop

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.L.

    1995-03-01

    When the Defense Waste Processing Facility (DWPF) is operational, processed radioactive sludge will be transferred in batches to the Slurry Mix Evaporator (SME), where glass frit will be added and the contents concentrated by boiling. Batches of the slurry mixture are transferred from the SME to the Melter Feed Tank (MFT). Hydragard{reg_sign} sampling systems are used on the SME and the MFT for collecting slurry samples in vials for chemical analysis. An accurate replica of the Hydragard sampling system was built and tested in the thermal Fluids Laboratory (TFL) to determine the hydragard accuracy. It was determined that the original Hydragard valve frequently drew a non-representative sample stream through the sample vial that ranged from frit enriched to frit depleted. The Hydragard valve was modified by moving the plunger and its seat backwards so that the outer surface of the plunger was flush with the inside diameter of the transfer line when the valve was open. The slurry flowing through the vial accurately represented the composition of the slurry in the reservoir for two types of slurries, different dilution factors, a range of transfer flows and a range of vial flows. It was then found that the 15 ml of slurry left in the vial when the Hydragard valve was closed, which is what will be analyzed at DWPF, had a lower ratio of frit to sludge as characterized by the lithium to iron ratio than the slurry flowing through it. The reason for these differences is not understood at this time but it is recommended that additional experimentation be performed with the TFL Hydragard loop to determine the cause.

  11. TRUEX Radiolysis Testing Using the INL Radiolysis Test Loop: FY-2012 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Dean R. Peterman; Lonnie G. Olson; Richard D. Tillotson; Rocklan G. McDowell; Jack D. Law

    2012-09-01

    The INL radiolysis test loop has been used to evaluate the affect of radiolytic degradation upon the efficacy of the strip section of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. The nominal composition of the TRUEX solvent used in this study is 0.2 M CMPO and 1.4 M TBP dissolved in n-dodecane and the nominal composition of the TRUEX strip solution is 1.5 M lactic acid and 0.050 M diethylenetriaminepentaacetic acid. Gamma irradiation of a mixture of TRUEX process solvent and stripping solution in the test loop does not adversely impact flowsheet performance as measured by stripping americium ratios. The observed increase in americium stripping distribution ratios with increasing absorbed dose indicates the radiolytic production of organic soluble degradation compounds.

  12. Thermal Vacuum Test of GLAS Propylene Loop Heat Pipe Development Model

    Science.gov (United States)

    Baker, Charles; Butler, Dan; Ku, Jentung; Kaya, Tarik; Nikitkin, Michael

    2000-01-01

    This paper presents viewgraphs on Thermal Vacuum Tests of the GLAS (Geoscience Laser Altimeter System) Propylene Loop Heat Pipe Development Model. The topics include: 1) Flight LHP System (Laser); 2) Test Design and Objectives; 3) DM (Development Model) LHP (Loop Heat Pipe) Test Design; 4) Starter Heater and Coupling Blocks; 5) CC Control Heaters and PRT; 6) Heater Plates (Shown in Reflux Mode); 7) Startup Tests; 8) CC Control Heater Power Tests for CC Temperature Control; and 9) Control Temperature Stability.

  13. The re-instrumentation irradiation test of nuclear fuel using fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Yong; Joung, C. Y.; Hong, J. T.; Ahn, S. H.; Choo, K. N. [KAERI, Daejeon (Korea, Republic of)

    2011-07-15

    This report is the status art report on re-instrumentation. The main techniques described in this report are technology that is developed in Norway HALDEN and domestic research facilities. Although re-instrumentation is not gone vigorously after 1990, HALDEN's re-instrumentation equipment was made until recently. In the meantime, re-instrumentation research was gone in domestic, but irradiation test did not performed actually. But DUPIC fuel irradiation is similar to re-instrumentation, so the irradiation test can be utilized directly to the Fuel Test Loop

  14. Design of Test Loops for Forced Convection Heat Transfer Studies at Supercritical State

    Science.gov (United States)

    Balouch, Masih N.

    Worldwide research is being conducted to improve the efficiency of nuclear power plants by using supercritical water (SCW) as the working fluid. One such SCW reactor considered for future development is the CANDU-Supercritical Water Reactor (CANDU-SCWR). For safe and accurate design of the CANDU-SCWR, a detailed knowledge of forced-convection heat transfer in SCW is required. For this purpose, two supercritical fluid loops, i.e. a SCW loop and an R-134a loop are developed at Carleton University. The SCW loop is designed to operate at pressures as high as 28 MPa, temperatures up to 600 °C and mass fluxes of up to 3000 kg/m2s. The R-134a loop is designed to operate at pressures as high as 6 MPa, temperatures up to 140 °C and mass fluxes in the range of 500-6000 kg/m2s. The test loops designs allow for up to 300 kW of heating power to be imparted to the fluid. Both test loops are of the closed-loop design, where flow circulation is achieved by a centrifugal pump in the SCW loop and three parallel-connected gear pumps in the R-134a loop, respectively. The test loops are pressurized using a high-pressure nitrogen cylinder and accumulator assembly, which allows independent control of the pressure, while simultaneously dampening pump induced pressure fluctuations. Heat exchangers located upstream of the pumps control the fluid temperature in the test loops. Strategically located measuring instrumentation provides information on the flow rate, pressure and temperature in the test loops. The test loops have been designed to accommodate a variety of test-section geometries, ranging from a straight circular tube to a seven-rod bundle, achieving heat fluxes up to 2.5 MW/m2 depending on the test-section geometry. The design of both test loops allows for easy reconfiguration of the test-section orientation relative to the gravitational direction. All the test sections are of the directly-heated design, where electric current passing through the pressure retaining walls of the

  15. The Phillips Laboratory capillary pumped loop test facility

    Science.gov (United States)

    Gluck, Donald F.; Kaylor, Marc C.

    1996-03-01

    An ammonia capillary pumped loop (CPL) test facility has been designed, fabricated, subject to acceptance tests, and assembled at Phillips Laboratory. Its intent is to support a wide range of Air Force programs, bringing CPL technology to flight readiness for operational systems. The facility provides a high degree of modularity and flexibility with several heating and cooling options, and capability for elevation (+/- 15 in.), tilt (+/-60°) and transport length variation. It has a 182 by 44 by 84 inch envelope, an expected heat load capability of 2500 W, and a temperature range of 0 to 50 °C. The evaporator section has two plates with four capillary pumps (CPs) each, with a starter pump on one plate. The CPs are 5/8 in., with TAG aluminum 6063-T6 casing and UHMW polyethylene wicks. The active lengths are 15 and 30 inch with both 10 and 15 micron wicks. The individual CPs have thermal and hydraulic isolation capability, and are removable. The transport section consists of stainless steel lines in a serpentine configuration, a 216 in3 free volume reservoir, and a mechanical pump. The vapor transport line contains a capillary device (which can be bypassed) for vapor blockage during startup. The condenser consists of two separately valved, parallel cold plates each with a downstream noncondensible gas trap. Cooling of up to 1500 W at -50 °C is provided by an FTS Systems chiller using Flourinert FC-72. An enclosure/exhaust system is provided for safety and emergency venting of ammonia. An ammonia charge station performs or supports the functions of proof pressure, flushing with ammonia, purging with gaseous nitrogen, evacuation of all or part of the CPL to 20 microns, and charging. Instrumentation consists of over 116 thermocouples, five of which are internal; one absolute and six differential pressure transducers; eleven watt transducers, and a reservoir load cell. The data acquisition system consists of a temperature scanner, Bernoulli drive, and two Macintosh

  16. Review of design criteria and safety analysis of safety class electric building for fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. Y.

    1998-02-01

    Steady state fuel test loop will be equipped in HANARO to obtain the development and betterment of advanced fuel and materials through the irradiation tests. HANARO fuel test loop was designed for CANDU and PWR fuel testing. Safety related system of Fuel Test Loop such as emergency cooling water system, component cooling water system, safety ventilation system, high energy line break mitigation system and remote control room was required 1E class electric supply to meet the safety operation in accordance with related code. Therefore, FTL electric building was designed to construction and install the related equipment based on seismic category I. The objective of this study is to review the design criteria and analysis the safety function of safety class electric building for fuel test loop, and this results will become guidance for the irradiation testing in future. (author). 10 refs., 6 tabs., 30 figs.

  17. Digitalization optical open loop test system for fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Deng-wei; SHU Xiao-wu; MU Xu-dong; LIU Cheng

    2006-01-01

    In order to receive and process the open loop signal from fiber optic gyroscopes speedily,stably and expediently,and to realize the amity interface between human and machine,a digital system that can convert GPIB (general purpose interface bus ) parallel bus into Universal Serial Bus is developed.All the interface functions of GP1B and the hardware system are realized through FPGA.With a digital sampling and processing system designed with VC++ in Windows platform,the real-time controlling procedure,high-speed receiving and sending data can be carried out,and the results can be displayed too.So the design of the system is flexible,the reliability and the stability are improved,error rate is no more than 10-11,the highest bit rate is 8 MB/s and the open loop detection system for optic fiber gyros achieves standardization and complete digitalization simultaneously.

  18. Megawatt Scale Hardware-in-the-Loop Testing of a High Speed Generator

    Science.gov (United States)

    2012-02-01

    designed for 1.2 MW continuous and 2.5 MW intermittent power. The generator is a two-stage machine composed of a brushless DC exciter and main...operators with the case interface. A simulation model of the entire PHIL test setup (dynamometer, gearbox, generator , rectifier, VVS, etc.), including...Hardware-in-the-Loop Testing of a High Speed Generator ABSTRACT A megawatt scale test bed for power hardware- in-the-loop experimentation with high

  19. Neural network setpoint control of an advanced test reactor experiment loop simulation

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, G.A.; Bryan, S.R.; Powell, R.H.; Chick, D.R.

    1990-09-01

    This report describes the design, implementation, and application of artificial neural networks to achieve temperature and flow rate control for a simulation of a typical experiment loop in the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). The goal of the project was to research multivariate, nonlinear control using neural networks. A loop simulation code was adapted for the project and used to create a training set and test the neural network controller for comparison with the existing loop controllers. The results for three neural network designs are documented and compared with existing loop controller action. The neural network was shown to be as accurate at loop control as the classical controllers in the operating region represented by the training set. 9 refs., 28 figs., 2 tabs.

  20. Results from Carbon Dioxide Washout Testing Using a Suited Manikin Test Apparatus with a Space Suit Ventilation Test Loop

    Science.gov (United States)

    Chullen, Cinda; Conger, Bruce; McMillin, Summer; Vonau, Walt; Kanne, Bryan; Korona, Adam; Swickrath, Mike

    2016-01-01

    NASA is developing an advanced portable life support system (PLSS) to meet the needs of a new NASA advanced space suit. The PLSS is one of the most critical aspects of the space suit providing the necessary oxygen, ventilation, and thermal protection for an astronaut performing a spacewalk. The ventilation subsystem in the PLSS must provide sufficient carbon dioxide (CO2) removal and ensure that the CO2 is washed away from the oronasal region of the astronaut. CO2 washout is a term used to describe the mechanism by which CO2 levels are controlled within the helmet to limit the concentration of CO2 inhaled by the astronaut. Accumulation of CO2 in the helmet or throughout the ventilation loop could cause the suited astronaut to experience hypercapnia (excessive carbon dioxide in the blood). A suited manikin test apparatus (SMTA) integrated with a space suit ventilation test loop was designed, developed, and assembled at NASA in order to experimentally validate adequate CO2 removal throughout the PLSS ventilation subsystem and to quantify CO2 washout performance under various conditions. The test results from this integrated system will be used to validate analytical models and augment human testing. This paper presents the system integration of the PLSS ventilation test loop with the SMTA including the newly developed regenerative Rapid Cycle Amine component used for CO2 removal and tidal breathing capability to emulate the human. The testing and analytical results of the integrated system are presented along with future work.

  1. Conceptual Design of Forced Convection Molten Salt Heat Transfer Testing Loop

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal; Piyush Sabharwall; Pattrick Calderoni; Alan K. Wertsching; S. Brandon Grover

    2010-09-01

    This report develops a proposal to design and construct a forced convection test loop. A detailed test plan will then be conducted to obtain data on heat transfer, thermodynamic, and corrosion characteristics of the molten salts and fluid-solid interaction. In particular, this report outlines an experimental research and development test plan. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project highlighted how thermophysical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report describes the options available to reach such objectives. In particular, that report outlines an experimental research and development test plan that would include following steps: •Molten Salts: The candidate molten salts for investigation will be selected. •Materials of Construction: Materials of construction for the test loop, heat exchangers, and fluid-solid corrosion tests in the test loop will also be selected. •Scaling Analysis: Scaling analysis to design the test loop will be performed. •Test Plan: A comprehensive test plan to include all the tests that are being planned in the short and long term time frame will be developed. •Design the Test Loop: The forced convection test loop will be designed including extensive mechanical design, instrument selection, data acquisition system, safety requirements, and related precautionary measures. •Fabricate the Test Loop. •Perform the Tests. •Uncertainty Analysis: As a part of the data collection, uncertainty analysis will

  2. Real-Time Hardware-in-the-Loop Testing for Digital Controllers

    DEFF Research Database (Denmark)

    Cha, Seung-Tae; Kwon, Park In; Wu, Qiuwei

    2012-01-01

    This paper discusses general approaches and results of real-time hardware-in-the-loop (HIL) testing for power electronics controllers. Many different types of power electronic controllers can be tested by connecting them to a real-time digital simulator (RTDS) for closed-loop HIL testing....... In this paper, two HIL digital controller tests are presented as application examples of the low-level signal interface in the closed-loop tests of power electronic controllers. In the HIL tests, the power system and the power electronics hardware are modeled in the RTDS. The required control functions....... Results of the HIL tests and hardware validations are presented to illustrate the real-time HIL testing method for power electronics controllers....

  3. Safety Analyses on Loss of Class IV power for the HANARO fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. K.; Lee, J. M.; Sim, B. S.; Chi, D. Y.; Ahn, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    A fuel test loop (FTL) for irradiation tests is under development at the HANARO. The construction of the FTL had been completed at the beginning of last year and pre-service tests have been carried out. The safety of the FTL including the PWR test fuels which will be installed at the end of this year should be verified for design basis accidents and anticipated operational occurrences (AOOs). This paper deals with the thermal-hydraulic transient analyses and the prediction for a departure from a nucleate boiling ratio (DNBR) during a loss of class IV power for the HANARO fuel test loop, which is one of the AOOs.

  4. Safety Analyses on a Safety Valve Stuck-Open for the HANARO fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. K.; Sim, B. S.; Chi, D. Y.; Lee, J. M.; Lee, C. Y.; Ahn, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    A fuel test loop (FTL) for irradiation tests is under development at the HANARO. The construction of the FTL was completed at the beginning of 2007 and integral performance tests have been carried out. The safety of the FTL including the PWR test fuels which will be installed should be verified for design basis accidents and anticipated operational occurrences (AOOs). This paper deals with the thermal-hydraulic transient analyses and the prediction for a departure from a nucleate boiling ratio (DNBR) during a safety valve stuck-open for the HANARO fuel test loop, which is one of the AOOs.

  5. Testing of a Neon Loop Heat Pipe for Large Area Cryocooling

    Science.gov (United States)

    Ku, Jentung; Robinson, Franklin Lee

    2014-01-01

    Cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks is required for future NASA missions. A cryogenic loop heat pipe (CLHP) can provide a closed-loop cooling system for this purpose and has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A neon CLHP was tested extensively in a thermal vacuum chamber using a cryopump as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components. Tests conducted included loop cool-down from the ambient temperature, startup, power cycle, heat removal capability, loop capillary limit and recovery from a dry-out, low power operation, and long duration steady state operation. The neon CLHP demonstrated robust operation. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by applying power to both the pump and evaporator without any pre-conditioning. It could adapt to changes in the pump power andor evaporator power, and reach a new steady state very quickly. The evaporator could remove heat loads between 0.25W and 4W. When the pump capillary limit was exceeded, the loop could resume its normal function by reducing the pump power. Steady state operations were demonstrated for up to 6 hours. The ability of the neon loop to cool large areas was therefore successfully verified.

  6. Optimal closed-loop identification test design for internal model control

    Institute of Scientific and Technical Information of China (English)

    张立群; 邵惠鹤; 戴丹

    2004-01-01

    In this paper, optimal cloeed-loop test design for control is studied. The identified model is used for controller design. The control scheme used is internal model control (IMC) and the design constraint is the power of the process output or that of the reference signal. The measure of performance is the variance of the error between the output of the ideal closed-loop system (with the ideal controller) and that of the actual closed-loop system (with the controller computed from the identified model). Optimal spectrum formulae can be used to determine the PRBS signal in industrious identification.

  7. Test results of reliable and very high capillary multi-evaporators / condenser loop

    Energy Technology Data Exchange (ETDEWEB)

    Van Oost, S.; Dubois, M.; Bekaert, G. [Societe Anonyme Belge de Construction Aeronautique - SABCA (Belgium)

    1996-12-31

    The paper present the results of various SABCA activities in the field of two-phase heat transport system. These results have been based on a critical review and analysis of the existing two-phase loop and of the future loop needs in space applications. The research and the development of a high capillary wick (capillary pressure up to 38 000 Pa) are described. These activities have led towards the development of a reliable high performance capillary loop concept (HPCPL), which is discussed in details. Several loop configurations mono/multi-evaporators have been ground tested. The presented results of various tests clearly show the viability of this concept for future applications. Proposed flight demonstrations as well as potential applications conclude this paper. (authors) 7 refs.

  8. Hardware-in-the-loop (HIL) Test of Demand as Frequency Controlled Reserve (DFR)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Zimmermann, K.; Østergaard, Jacob;

    2016-01-01

    This paper presents the hardware-in-the-loop (HIL) test of the demand as frequency controlled reserve (DFR). The HIL test refers to a test in which parts of a pure simulation have been replaced by actual physical components. It is used to understand the behavior of a new device or controller...

  9. Testing Loop Quantum Gravity and Electromagnetic Dark Energy in Superconductors

    CERN Document Server

    de Matos, Clovis Jacinto

    2008-01-01

    In 1989 Cabrera and Tate reported an anomalous excess of mass of the Cooper pairs in rotating thin Niobium rings. So far, this experimental result never received a proper theoretical explanation in the context of superconductor's physics. In the present work we argue that what Cabrera and Tate interpreted as an anomalous excess of mass can also be associated with a deviation from the classical gravitomagnetic Larmor theorem due to the presence of dark energy in the superconductor, as well as with the discrete structure of the area of the superconducting Niobium ring as predicted by Loop Quantum Gravity. From Cabrera and Tate measurements we deduce that the quantization of spacetime in superconducting circular rings occurs at the Planck-Einstein scale $l_{PE} = (\\hbar G/c^3 \\Lambda)^{1/4}\\sim 3.77\\times 10 ^{-5} m$, instead of the Planck scale $l_{P} =(\\hbar G / c^3)^{1/2}=1.61 \\times 10 ^{-35} m$, with an Immirzi parameter which depends on the specific critical temperature of the superconducting material and ...

  10. Review of application code and standards for mechanical and piping design of HANARO fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. Y.

    1998-02-01

    The design and installation of the irradiation test facility for verification test of the fuel performance are very important in connection with maximization of the utilization of HANARO. HANARO fuel test loop was designed in accordance with the same code and standards of nuclear power plant because HANARO FTL will be operated the high pressure and temperature same as nuclear power plant operation conditions. The objective of this study is to confirm the propriety of application code and standards for mechanical and piping of HANARO fuel test loop and to decide the technical specification of FTL systems. (author). 18 refs., 8 tabs., 6 figs.

  11. Commissioning of filtered containment venting test loop Java plus

    Energy Technology Data Exchange (ETDEWEB)

    Beiseigel, A.; El-Rharbaoui, F.; Wich, M.

    2013-07-01

    AREVA GmbH operates a unique Thermal-hydraulic platform in Germany, France and USA. It is recognized as a test body according to ISO 17025. The Deutsche Akkreditierungsstelle GmbH (DAkkS - German Society for Accreditation) has also certified the Thermal-hydraulic platform as an independent inspection body Type C according to ISO 17020. A part of this platform is the Component Laboratory located in Karlstein, Germany which is in operation for more than 50 years. The testing activities cover a wide range as: Critical Heat Flux Tests, Valve Testing and LOCA Qualification of safety related components. Since 2012 the component Qualification Karlstein reactivated their testing scope for Filtered Containment Venting System (FCVS) Tests which is to our knowledge the largest (mass flow and volume) dedicated FCVS test facility.

  12. Summary of TRUEX Radiolysis Testing Using the INL Radiolysis Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Dean R. Peterman; Lonnie G. Olson; Rocklan G. McDowell; Gracy Elias; Jack D. Law

    2012-03-01

    The INL radiolysis and hydrolysis test loop has been used to evaluate the effects of hydrolytic and radiolytic degradation upon the efficacy of the TRUEX flowsheet for the recovery of trivalent actinides and lanthanides from acidic solution. Repeated irradiation and subsequent re-conditioning cycles did result in a significant decrease in the concentration of the TBP and CMPO extractants in the TRUEX solvent and a corresponding decrease in americium and europium extraction distributions. However, the build-up of solvent degradation products upon {gamma}-irradiation, had little impact upon the efficiency of the stripping section of the TRUEX flowsheet. Operation of the TRUEX flowsheet would require careful monitoring to ensure extraction distributions are maintained at acceptable levels.

  13. Resume of KER Loop irradiation tests for 1957, 1958, and 1959

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, W.K.

    1960-03-28

    In 1957 three of the four high temperature recirculating loops in KE Reactor were put into service and in 1958 the fourth loop was started up. The primary purpose of the loops has been high temperature irradiation testing of fuel elements in support of the NPR fuel element development program, although tests have been run to provide information for PRTR fuel development and high temperature aluminum corrosion programs. Coolant technology studies relating to activity build-up, crude formation, corrosion, failure detection, and decontamination are carried on in conjunction with the fuel element tests. The purpose of this document is to provide a resume of all fuel element test irradiations in the KER Loops from the time they started up to the end of CY-1959. A description of each test, its operating conditions, a chronological history of each loop, and a bibliography of documents pertaining to the tests are included. Supplements to this report will be issued periodically to bring the information up to date.

  14. Thermal analysis of lithium cooled natural circulation loop module for fuel rod testing in the Fast Flux Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Eyler, L.L.; Kim, D.; Stover, R.L.; Beaver, T.R.

    1987-01-01

    Maximum heat removal capability of a lithium cooled natural circulation fuel rod test module design is determined. Loop geometry is optimized within limitations of design specifications for nominal operation temperatures, materials, and test module environment. Results provide test module operation limits and range of potential uncertainties. 3 refs., 12 figs.

  15. Decentralized identification for multivariable integrating processes with time delays from closed-loop step tests.

    Science.gov (United States)

    Mei, Hua; Li, Shaoyuan

    2007-04-01

    In order to identify those multivariable processes with integrating factors in their transfer function matrices, a simple yet robust decentralized identification method from closed-loop step tests is proposed. By the frequency response matrix computed from the closed-loop system data and the knowledge of the decentralized controller, the structural information of the multivariable integrating process is determined firstly and then the continuous parametric model with dead times is approximated similarly with the parameterization of the open-loop stable process. Computer simulations and an application to a 3 x 3 integrating multiple-tank water level system verify the validation of the proposed method even if the closed-loop system is affected by some stochastic noise sources.

  16. Portland, Oregon Test Data Set Arterial Loop Detector Data

    Data.gov (United States)

    Department of Transportation — This set of data files was acquired under USDOT FHWA cooperative agreement DTFH61-11-H-00025 as one of the four test data sets acquired by the USDOT Data Capture and...

  17. Development of a Forced-Convection Liquid-Fluoride-Salt Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Yoder Jr, Graydon L [ORNL; Wilson, Dane F [ORNL; Peretz, Fred J [ORNL; Wilgen, John B [ORNL; Romanoski, Glenn R [ORNL; Kisner, Roger A [ORNL; Holcomb, David Eugene [ORNL; Heatherly, Dennis Wayne [ORNL; Aaron, Adam M [ORNL

    2010-01-01

    A small forced-convection molten-fluoride-salt loop is being constructed at Oak Ridge National Laboratory to examine the heat transfer behavior of FLiNaK salt in a heated pebble bed. Objectives of the experiment include reestablishing infrastructure needed for fluoride-salt loop testing, developing a unique inductive heating technique for performing heat transfer (or other) experiments, measuring heat transfer characteristics in a liquid-fluoride-salt-cooled pebble bed, and demonstrating the use of silicon carbide (SiC) as a structural component for salt systems. The salt loop will consist of an Inconel 600 piping system, a sump-type pump, a SiC test section, and an air-cooled heat exchanger, as well as auxiliary systems needed to pre-heat the loop, transport salt into and out of the loop, and maintain an inert cover gas over the salt. A 30,000 Hz inductive heating system will be used to provide up to 250 kW of power to a 15 cm diameter SiC test section containing a packed bed of 3 cm graphite spheres. A SiC-to-Inconel 600 joint will use a conventional nickel/grafoil spiral wound gasket sandwiched between SiC and Inconel flanges. The loop system can provide up to 4.5 kg/s of salt flow at a head of 0.125 MPa and operate at a pressure just above atmospheric. Pebble Reynolds numbers of up to 2600 are possible with this configuration. A sump system is provided to drain and store the salt when not in use. Instrumentation on the loop will include pressure, temperature, and flow measurements, while the test section will be instrumented to provide pebble and FLiNaK temperatures.

  18. The safety concept and classification for HANARO fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. Y.

    1997-10-01

    The design and installation of the irradiation test facility for verification test of the fuel performance are very important in connection with maximization of the utilization of HANARO. The principle subjects of this study is to determine the safety concept and classification of HANARO FTL for the design of systems. HANARO FTL should be approved by KINS for installation and operation. And these irradiation for facilities will be designed and installed based upon the safety concept and classification results. (author). 14 refs., 12 tabs., 10 figs.

  19. Three tritium systems test assembly (TSTA) off-loop experiments

    Energy Technology Data Exchange (ETDEWEB)

    Talcott, C.L.; Anderson, J.L.; Carlson, R.V.; Coffin, D.O.; Walthers, C.R.; Hamerdinger, D.; Binning, K.; Trujillo, R.D.; Moya, J.S. [Los Alamos National Lab., NM (United States); Hayashi, T.; Okuno, K.; Yamanishi, T. [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1993-11-01

    This report contains the results from three different experiments. Experiment one was initiated to establish the possibility of using a soft elastomer in ITER (International Thermonuclear Experimental Reactor) applications. Used in this application, the sealing material is anticipated to be in tritium at pressures in the range of 1 {times} 10{sup {minus}3} torr for many years. Here two O-ring valve seals each of Viton-A, Buna-N, and EDPM were exposed to 1, 40, or 400 torr of tritium while being cycled open and closed approximately 11,500 times in 192 days. EDPM is the least susceptible to damage from the tritium. Both Buna-N and Viton-A showed deterioration following the first cycling at 400 torr. Using commercially available materials, the Tritium Systems Test Assembly (TSTA) designed and built a Portable Water Removal (PWR) Unit to reduce tritium oxide emissions during glovebox breaches. The PWR removes 99.9% of all tritium and saves between 0.7 and 3.5 curies of tritium oxide from being stacked during each of the five tests. Finally, a series of tests are done to determine whether the presence of SF{sub 6} changes the ability of palladium and platinum to catalyze the T{sub 2}-O{sub 2} reaction to form T{sub 2}O. No deterioration of the catalytic activity is observed. This is important because the Tokamak Fusion Test Reactor (TFTR) requires information about the effect of SF{sub 6}, an electrical insulator, on the catalytic behavior of Pt and Pd in a T{sub 2} environment. This information is necessary for the accident analysis in the Safety Analysis Report for TFTR. This study is done using an apparatus supplied to TSTA by TFTR.

  20. Design of a Test Loop for Performance Testing of Steam Turbines Under a Variety of Operating Conditions

    Science.gov (United States)

    Guerrette, Jonathan

    The steam turbine is one of the most widely used energy conversion devices in the world, providing shaft power for electricity production, chemical processing, and HVAC systems. There are new opportunities in growing renewable and combined cycle applications. End-users are asking for energy efficiency improvements that require manufacturers to renew their experimentally verified design methods. A structured design approach was carried out along three integrated research thrusts. The first two thrusts, Turbine Performance Prediction and Measurement Planning, were carried out with the aim of supporting the theoretical modeling required for the third thrust, System Modeling. The primary use of the steam turbine test loop will be to improve performance prediction techniques. Thus the primary focus of the first thrust was to describe empirical loss correlations found in the literature. For the second thrust, a preliminary review of measurement codes and standards was carried out to determine their impact on overall test loop design. For the third thrust, quasi-steady theoretical models were derived from first principles for the turbine, condenser, pump, boiler, and pipe components using control volume analyses. The theoretical models were implemented in a new open source simulation environment that carries out the calculation process over a range of up-to three turbine model inputs. A parametric study was undertaken with the goal of defining preliminary design specifications for the test loop components. The test loop was simulated across a wide range of steady states for three different turbine blade configurations, each at three different values of the blade row enthalpy-loss coefficient. The parametric study demonstrates full coverage of possible turbine operating conditions. The results of the simulations were analyzed to narrow the required operating range of the test loop to a series of turbine test paths. The final operational envelope yielded a set of test loop

  1. Sensory feedback in prosthetics: a standardized test bench for closed-loop control.

    Science.gov (United States)

    Dosen, Strahinja; Markovic, Marko; Hartmann, Cornelia; Farina, Dario

    2015-03-01

    Closing the control loop by providing sensory feedback to the user of a prosthesis is an important challenge, with major impact on the future of prosthetics. Developing and comparing closed-loop systems is a difficult task, since there are many different methods and technologies that can be used to implement each component of the system. Here, we present a test bench developed in Matlab Simulink for configuring and testing the closed-loop human control system in standardized settings. The framework comprises a set of connected generic blocks with normalized inputs and outputs, which can be customized by selecting specific implementations from a library of predefined components. The framework is modular and extensible and it can be used to configure, compare and test different closed-loop system prototypes, thereby guiding the development towards an optimal system configuration. The use of the test bench was demonstrated by investigating two important aspects of closed-loop control: performance of different electrotactile feedback interfaces (spatial versus intensity coding) during a pendulum stabilization task and feedforward methods (joystick versus myocontrol) for force control. The first experiment demonstrated that in the case of trained subjects the intensity coding might be superior to spatial coding. In the second experiment, the control of force was rather poor even with a stable and precise control interface (joystick), demonstrating that inherent characteristics of the prosthesis can be an important limiting factor when considering the overall effectiveness of the closed-loop control. The presented test bench is an important instrument for investigating different aspects of human manual control with sensory feedback.

  2. Breath hydrogen test in infants and children with blind loop syndrome.

    Science.gov (United States)

    Nose, O; Kai, H; Harada, T; Ogawa, M; Maki, I; Tajiri, H; Kanaya, S; Kimura, S; Shimizu, K; Yabuuchi, H

    1984-06-01

    Breath hydrogen production after oral lactose loading was examined in infants and children with stagnant loop syndrome, blind loop syndrome, or both. All six infants under 3 years of age had bacteriological evidence of small intestinal colonization. The characteristics of the breath hydrogen test in this syndrome are: (a) extremely high basal excretion of breath hydrogen (after overnight fasting); (b) an earlier and greater breath hydrogen value (0.293 +/- 0.201 ml/min/m2: mean +/- SD) after oral lactose administration than formed in lactose malabsorption alone (0.050 +/- 0.041 ml/min/m2); and (c) the observation of a sustained hydrogen rise over several hours. This investigation demonstrated that the breath hydrogen test is a promising and noninvasive tool for diagnosing blind (or stagnant) loop syndrome.

  3. Corrosion test in the Experimental loop for an ITER TBM liquid breeder

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jae Sung; Kim, Suk Kwon; Lee, Eo Hwak; Lee, Seung Jae; Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    An Experimental Loop for Liquid breeder (ELLI) was constructed for the purpose of validating the electromagnetic (EM) pump design, which designed and fabricated by ourselves: testing the effects of magneto-hydro-dynamics (MHD): and investigating the compatibility of PbLi using structural materials such as ferritic martensitic steel. In the ELLI, Pb-15.7Li, where Li is 15.7 at % (called PbLi hereafter), is used as the breeding material and an EM pump circulates it in the loop with the maximum flow rate of 60 lpm. The operating pressure and temperature in the loop are 0.4 MPa and 300 .deg. C, respectively and the maximum operating pressure and temperature are 0.5 MPa and 550 .deg. C, respectively. After the performance test on each component such as heaters, the control systems for heating the loop and the characteristic tests with a magnet and the EM pump, long-term operational tests of the EM pump were performed during three different corrosion tests. The corrosion tests were performed in the ELLI loop by forced convection circulation using an EM pump to investigate the corrosion behavior of FMS in flowing PbLi. For the corrosion specimens, two samples were fabricated using Grade 91 FMS: tubular-type and cylindrical-type specimens. The specimens were exposed to the flowing PbLi with a speed of 0.16 m/s at 340 .deg. C for the three different experiments. The corrosion tests by forced convection using an EM pump can conveniently vary the speed of a liquid breeder by changing the currents of the EM pump than that of using a thermal convection

  4. Hardware-in-the-Loop Rendezvous Tests of a Novel Actuators Command Concept

    Science.gov (United States)

    Gomes dos Santos, Willer; Marconi Rocco, Evandro; Boge, Toralf; Benninghoff, Heike; Rems, Florian

    2016-09-01

    Integration, test and validation results, in a real-time environment, of a novel concept for spacecraft control are presented in this paper. The proposed method commands simultaneously a group of actuators optimizing a given set of objective functions based on a multiobjective optimization technique. Since close proximity maneuvers play an important role in orbital servicing missions, the entire GNC system has been integrated and tested at a hardware-in-the-loop (HIL) rendezvous and docking simulator known as European Proximity Operations Simulator (EPOS). During the test campaign at EPOS facility, a visual camera has been used to provide the necessary measurements for calculating the relative position with respect to the target satellite during closed-loop simulations. In addition, two different configurations of spacecraft control have been considered in this paper: a thruster reaction control system and a mixed actuators mode which includes thrusters, reaction wheels, and magnetic torqrods. At EPOS, results of HIL closed-loop tests have demonstrated that a safe and stable rendezvous approach can be achieved with the proposed GNC loop.

  5. Testing of the Geoscience Laser Altimeter System (GLAS) Prototype Loop Heat Pipe

    Science.gov (United States)

    Douglas, Donya; Ku, Jentung; Kaya, Tarik

    1998-01-01

    This paper describes the testing of the prototype loop heat pipe (LHP) for the Geoscience Laser Altimeter System (GLAS). The primary objective of the test program was to verify the loop's heat transport and temperature control capabilities under conditions pertinent to GLAS applications. Specifically, the LHP had to demonstrate a heat transport capability of 100 W, with the operating temperature maintained within +/-2K while the condenser sink was subjected to a temperature change between 273K and 283K. Test results showed that this loop heat pipe was more than capable of transporting the required heat load and that the operating temperature could be maintained within +/-2K. However, this particular integrated evaporator-compensation chamber design resulted in an exchange of energy between the two that affected the overall operation of the system. One effect was the high temperature the LHP was required to reach before nucleation would begin due to inability to control liquid distribution during ground testing. Another effect was that the loop had a low power start-up limitation of approximately 25 W. These Issues may be a concern for other applications, although it is not expected that they will cause problems for GLAS under micro-gravity conditions.

  6. Hardware-in-the-Loop Rendezvous Tests of a Novel Actuators Command Concept

    Science.gov (United States)

    Gomes dos Santos, Willer; Marconi Rocco, Evandro; Boge, Toralf; Benninghoff, Heike; Rems, Florian

    2016-12-01

    Integration, test and validation results, in a real-time environment, of a novel concept for spacecraft control are presented in this paper. The proposed method commands simultaneously a group of actuators optimizing a given set of objective functions based on a multiobjective optimization technique. Since close proximity maneuvers play an important role in orbital servicing missions, the entire GNC system has been integrated and tested at a hardware-in-the-loop (HIL) rendezvous and docking simulator known as European Proximity Operations Simulator (EPOS). During the test campaign at EPOS facility, a visual camera has been used to provide the necessary measurements for calculating the relative position with respect to the target satellite during closed-loop simulations. In addition, two different configurations of spacecraft control have been considered in this paper: a thruster reaction control system and a mixed actuators mode which includes thrusters, reaction wheels, and magnetic torqrods. At EPOS, results of HIL closed-loop tests have demonstrated that a safe and stable rendezvous approach can be achieved with the proposed GNC loop.

  7. Test Requirements and Conceptual Design for a Potassium Test Loop to Support an Advanced Potassium Rankine Cycle Power Conversion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, JR.G.L.

    2006-03-08

    Parameters for continuing the design and specification of an experimental potassium test loop are identified in this report. Design and construction of a potassium test loop is part of the Phase II effort of the project ''Technology Development Program for an Advanced Potassium Rankine Power Conversion System''. This program is supported by the National Aeronautics and Space Administration. Design features for the potassium test loop and its instrumentation system, specific test articles, and engineered barriers for ensuring worker safety and protection of the environment are described along with safety and environmental protection requirements to be used during the design process. Information presented in the first portion of this report formed the basis to initiate the design phase of the program; however, the report is a living document that can be changed as necessary during the design process, reflecting modifications as additional design details are developed. Some portions of the report have parameters identified as ''to be determined'' (TBD), reflecting the early stage of the overall process. In cases where specific design values are presently unknown, the report attempts to document the quantities that remain to be defined in order to complete the design of the potassium test loop and supporting equipment.

  8. Conceptual design of a thermalhydraulic loop for multiple test geometries at supercritical conditions named Supercritical Phenomena Experimental Test Apparatus (SPETA)

    Science.gov (United States)

    Adenariwo, Adepoju

    The efficiency of nuclear reactors can be improved by increasing the operating pressure of current nuclear reactors. Current CANDU-type nuclear reactors use heavy water as coolant at an outlet pressure of up to 11.5 MPa. Conceptual SuperCritical Water Reactors (SCWRs) will operate at a higher coolant outlet pressure of 25 MPa. Supercritical water technology has been used in advanced coal plants and its application proves promising to be employed in nuclear reactors. To better understand how supercritical water technology can be applied in nuclear power plants, supercritical water loops are used to study the heat transfer phenomena as it applies to CANDU-type reactors. A conceptual design of a loop known as the Supercritical Phenomena Experimental Apparatus (SPETA) has been done. This loop has been designed to fit in a 9 m by 2 m by 2.8 m enclosure that will be installed at the University of Ontario Institute of Technology Energy Research Laboratory. The loop include components to safely start up and shut down various test sections, produce a heat source to the test section, and to remove reject heat. It is expected that loop will be able to investigate the behaviour of supercritical water in various geometries including bare tubes, annulus tubes, and multi-element-type bundles. The experimental geometries are designed to match the fluid properties of Canadian SCWR fuel channel designs so that they are representative of a practical application of supercritical water technology in nuclear plants. This loop will investigate various test section orientations which are the horizontal, vertical, and inclined to investigate buoyancy effects. Frictional pressure drop effects and satisfactory methods of estimating hydraulic resistances in supercritical fluid shall also be estimated with the loop. Operating limits for SPETA have been established to be able to capture the important heat transfer phenomena at supercritical conditions. Heat balance and flow calculations have

  9. Testing FlexRay ECUs with a hardware-in-the-loop simulator; Test von FlexRay-Steuergeraeten am Hardware-in-the-Loop Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Stroop, J.; Koehl, S. [dSPACE GmbH, Paderborn (Germany); Peller, M.; Riedesser, P. [BMW AG, Muenchen (Germany)

    2005-07-01

    To master the data communication of complex and safety relevant systems within future vehicles, the BMW Group prepares the application of FlexRay. The accompanying development process plays an important role for the quality, stability and reliability of those systems. Hardware-in-the-loop simulation and test stands are indispensable constituents and they are an integral part of the validation process. The following contribution describes the technology that is used within the BMW Group in more detail, especially in terms of communication networks with FlexRay. (orig.)

  10. Corrosion test using commercial FMS and developed ARAA in the Experimental loop for liquid breeder

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. S.; Kim, S. K.; Lee, E. H.; Jin, H. G.; Lee, D. W.; Jung, Y. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, H. G. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A liquid-type TBM, a Helium Cooled Molten Lithium (HCML) TBM, is one of candidate TBM for KO Demos. In this concept, helium (He) and liquid lithium (Li) were used as a coolant and a breeder, respectively. However, according to our strategy for developing the liquid breeder TBM and its more relevant DEMO concept, liquid breeders not only considered liquid lithium but also lead-lithium (PbLi). An Experimental Loop for Liquid breeder (ELLI) was constructed for the purpose of validating the electromagnetic (EM) pump design, which designed and fabricated by ourselves; testing the effects of magneto-hydro-dynamics (MHD); and investigating the compatibility of PbLi using structural materials such as ferritic martensitic steel. The picture of the experimental loop is shown in Fig. 1. The performance test on each component such as heaters, the control systems for heating the loop were performed and the characteristic tests with a magnet and the EM pump were carried out. A corrosion tests using ELLI were performed with grade 91 FMS steel and ARAA during 250 hours. The corrosion tests specimens using developed commercial-scale ARAA-1 will be carried out in the ELLI loop using EM pump to investigate the corrosion behavior of ARAA-1, and the test results will be compared the previous corrosion tests of FMS corrosion specimens. A commercial FMS with grade 91 and developed ARAA steel was used for corrosion test-specimens to compare the corrosion characteristics in the flowing Pbli loop. Long term operation performance of the ELLI loop was conformed during 250 h corrosion tests. During the two separate experiments, an EM pump was operated for 250 h with a speed of 0.16 m/s (0.95 Kg/s) for corrosion tests. Mass of samples was decreased about 0.006% for ARAA-sample and 0.009% for Gr.91-sample, which corresponded to 0.22 g/m2 and 0.34 g/m2 of a corrosion attack, respectively. Unfortunately, it was unavailable to compare these weight losses with previous reports because of the

  11. Thermal test results of the two-phase thermal bus technology demonstration loop

    Science.gov (United States)

    Edelstein, Fred; Liandris, Maria; Rankin, J. Gary

    1987-01-01

    A two-phase heat transport system, the Thermal Bus Technology Demonstrator, has been built and tested for NASA Johnson Space Center for application on Space Station. The loop is a separated two-phase system that uses evaporator flow control valves and liquid condenser flooding to achieve temperature control. Both ambient and thermal vacuum tests have been completed in NASA's Chamber A, initially using Freon-11 and then ammonia as the working fluid. Overall, the tests were quite successful, with the bus achieving all major test objectives, including operation at 19.5 kW and set points at 35 F (1.7 C), 70 F (21.1 C) and 104 F (40.0 C), load sharing, asymmetrical heating and isothermality around the loop. Low plate to vapor temperature drops were obtained for the monogroove cold plate using ammonia and are indicative of the high evaporative film coefficients obtainable with this design.

  12. Hardware-in-the-loop (HIL) Test of Demand as Frequency Controlled Reserve (DFR)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Zimmermann, K.; Østergaard, Jacob

    2016-01-01

    This paper presents the hardware-in-the-loop (HIL) test of the demand as frequency controlled reserve (DFR). The HIL test refers to a test in which parts of a pure simulation have been replaced by actual physical components. It is used to understand the behavior of a new device or controller....... The DFR has been tested by offline simulations to illustrate the efficacy of this technology. The DFR control logics have been implemented in the SmartBox. The HIL was conducted by having the SmartBox connected to the real time simulations and the performance of the SmartBox was tested with difference...

  13. Utilizing a Suited Manikin Test Apparatus and Space Suit Ventilation Loop to Evaluate Carbon Dioxide Washout

    Science.gov (United States)

    Chullen, Cinda; Conger, Bruce; Korona, Adam; Kanne, Bryan; McMillin, Summer; Paul, Thomas; Norcross, Jason; Alonso, Jesus Delgado; Swickrath, Mike

    2015-01-01

    NASA is pursuing technology development of an Advanced Extravehicular Mobility Unit (AEMU) which is an integrated assembly made up of primarily a pressure garment system and a portable life support subsystem (PLSS). The PLSS is further composed of an oxygen subsystem, a ventilation subsystem, and a thermal subsystem. One of the key functions of the ventilation system is to remove and control the carbon dioxide (CO2) delivered to the crewmember. Carbon dioxide washout is the mechanism by which CO2 levels are controlled within the space suit helmet to limit the concentration of CO2 inhaled by the crew member. CO2 washout performance is a critical parameter needed to ensure proper and robust designs that are insensitive to human variabilities in a space suit. A suited manikin test apparatus (SMTA) was developed to augment testing of the PLSS ventilation loop in order to provide a lower cost and more controlled alternative to human testing. The CO2 removal function is performed by the regenerative Rapid Cycle Amine (RCA) within the PLSS ventilation loop and its performance is evaluated within the integrated SMTA and Ventilation Loop test system. This paper will provide a detailed description of the schematics, test configurations, and hardware components of this integrated system. Results and analysis of testing performed with this integrated system will be presented within this paper.

  14. Analysis of Fracture in Cores from the Tuff Confining Unit beneath Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2008-03-01

    The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.

  15. NaK Plugging Meter Design for the Feasibility Test Loops

    Science.gov (United States)

    Pearson, J. Boise; Godfroy, Thomas J.; Reid, Robert S.; Polzin, Kurt A.

    2008-01-01

    The design and predicted performance of a plugging meter for use in the measurement of NaK impurity levels are presented. The plugging meter is incorporated into a Feasibility Test Loop (FTL), which is a small pumped-NaK loop designed to enable the rapid, small-scale evaluation of techniques such as in situ purification methods and to permit the measurement of bulk material transport effects (not mechanisms) under flow conditions that are representative of a fission surface power reactor. The FTL operates at temperatures similar to those found in a reactor, with a maximum hot side temperature of 900 K and a corresponding cold side temperature of 860 K. In the plugging meter a low flow rate bypass loop is cooled until various impurities (primarily oxides) precipitate out of solution. The temperatures at which these impurities precipitate are indicative of the level of impurities in the NaK. The precipitates incrementally plug a small orifice in the bypass loop, which is detected by monitoring changes in the liquid metal flow rate.

  16. Design, development and test of a capillary pump loop heat pipe

    Science.gov (United States)

    Kroliczek, E. J.; Ku, J.; Ollendorf, S.

    1984-01-01

    The development of a capillary pump loop (CPL) heat pipe, including computer modeling and breadboard testing, is presented. The computer model is a SINDA-type thermal analyzer, combined with a pressure analyzer, which predicts the transients of the CPL heat pipe during operation. The breadboard is an aluminum/ammonia transport system which contains multiple parallel evaporator and condenser zones within a single loop. Test results have demonstrated the practicality and reliability of such a design, including heat load sharing among evaporators, liquid inventory/temperature control feature, and priming under load. Transport capability for this system is 65 KW-M with individual evaporator pumps managing up to 1.7 KW at a heat flux of 15 W/sq cm. The prediction of the computer model for heat transport capabilities is in good agreement with experimental results.

  17. Hardware-in-the-Loop Testing of Utility-Scale Wind Turbine Generators

    Energy Technology Data Exchange (ETDEWEB)

    Schkoda, Ryan [Clemson Univ., SC (United States); Fox, Curtiss [Clemson Univ., SC (United States); Hadidi, Ramtin [Clemson Univ., SC (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wallen, Robb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lambert, Scott [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-01-26

    Historically, wind turbine prototypes were tested in the field, which was--and continues to be--a slow and expensive process. As a result, wind turbine dynamometer facilities were developed to provide a more cost-effective alternative to field testing. New turbine designs were tested and the design models were validated using dynamometers to drive the turbines in a controlled environment. Over the years, both wind turbine dynamometer testing and computer technology have matured and improved, and the two are now being joined to provide hardware-in-the-loop (HIL) testing. This type of testing uses a computer to simulate the items that are missing from a dynamometer test, such as grid stiffness, voltage, frequency, rotor, and hub. Furthermore, wind input and changing electric grid conditions can now be simulated in real time. This recent advance has greatly increased the utility of dynamometer testing for the development of wind turbine systems.

  18. Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops

    OpenAIRE

    Andersson, Peter; Bjelkenstedt, Tom; Andersson Sundén, Erik; Sjöstrand, Henrik; Jacobsson, Staffan

    2015-01-01

    Detailed knowledge of the lateral distribution of steam (void) and water in a nuclear fuel assembly is of great value for nuclear reactor operators and fuel manufacturers, with consequences for both reactor safety and economy of operation. Therefore, nuclear relevant two-phase flows are being studied at dedicated thermal-hydraulic test loop, using twophase flow systems ranging from simplified geometries such as heated circular pipes to full scale mock-ups of nuclear fuel assemblies. Neutron t...

  19. Real-time open-loop frequency response analysis of flight test data

    Science.gov (United States)

    Bosworth, J. T.; West, J. C.

    1986-01-01

    A technique has been developed to compare the open-loop frequency response of a flight test aircraft real time with linear analysis predictions. The result is direct feedback to the flight control systems engineer on the validity of predictions and adds confidence for proceeding with envelope expansion. Further, gain and phase margins can be tracked for trends in a manner similar to the techniques used by structural dynamics engineers in tracking structural modal damping.

  20. Computer Measuring and Controlling System for Temperature Field at R1/R2 Test Section in ESPRESSO Loop

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Fei; WU; Chun-liang; SHEN; Feng-yang; GU; Chun-xing

    2012-01-01

    <正>ESPRESSO loop was the one of the sodium loops imported from Italy by the Fast Reactor of the China Institute of Atomic Energy, which would do necessary sodium experiments for developing core (include fuel rod assemblies, control rod assemblies) or for testing before domestic and foreign components into the reactor, i.e., the high temperature durability test, and the thermal shock test to test the

  1. Open-Loop Flight Testing of COBALT GN&C Technologies for Precise Soft Landing

    Science.gov (United States)

    Carson, John M., III; Amzajerdian, Farzin; Seubert, Carl R.; Restrepo, Carolina I.

    2017-01-01

    A terrestrial, open-loop (OL) flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed, with support through the NASA Advanced Exploration Systems (AES), Game Changing Development (GCD), and Flight Opportunities (FO) Programs. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuzes the NDL and LVS data in real time to produce a precise navigation solution that is independent of the Global Positioning System (GPS) and suitable for future, autonomous planetary landing systems. The OL campaign tested COBALT as a passive payload, with COBALT data collection and filter execution, but with the Xodiac vehicle Guidance and Control (G&C) loops closed on a Masten GPS-based navigation solution. The OL test was performed as a risk reduction activity in preparation for an upcoming 2017 closed-loop (CL) flight campaign in which Xodiac G&C will act on the COBALT navigation solution and the GPS-based navigation will serve only as a backup monitor.

  2. Detection Test for Leakage of CO{sub 2} into Sodium Loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This report is about the facility for the detection test for leakage of CO{sub 2} into sodium loop. The facility for the detection test for leakage of CO{sub 2} into sodium loop was introduced. The test will be carried out. Our experimental results are going to be expected to be used for approach methods to detect CO{sub 2} leaking into sodium in heat exchangers. A sodium-and-carbon dioxide (Na-CO{sub 2}) heat exchanger is one of the key components for the supercritical CO{sub 2} Brayton cycle power conversion system of sodium-cooled fast reactors (SFRs). A printed circuit heat exchanger (PCHE) is considered for the Na-CO{sub 2} heat exchanger, which is known to have potential for reducing the volume occupied by the exchangers compared to traditional shell-and-tube heat exchangers. Among various issues about the Na- CO{sub 2} exchanger, detection of CO{sub 2} leaking into sodium in the heat exchanger is most important thing for its safe operation. It is known that reaction products from sodium and CO{sub 2} such as sodium carbonate (Na{sub 2}CO{sub 3}) and amorphous carbon are hardly soluble in sodium, which cause plug sodium channels. Detection technique for Na{sub 2}CO{sub 3} in sodium loop has not been developed yet. Therefore, detection of CO{sub 2} and CO from reaction of sodium and CO{sub 2} are proper to detect CO{sub 2} leakage into sodium loop.

  3. ICFT: An initial closed-loop flow test of the Fenton Hill Phase II HDR reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Dash, Z.V. (ed.); Aguilar, R.G.; Dennis, B.R.; Dreesen, D.S.; Fehler, M.C.; Hendron, R.H.; House, L.S.; Ito, H.; Kelkar, S.M.; Malzahn, M.V.

    1989-02-01

    A 30-day closed-loop circulation test of the Phase II Hot Dry Rock reservoir at Fenton Hill, New Mexico, was conducted to determine the thermal, hydraulic, chemical, and seismic characteristics of the reservoir in preparation for a long-term energy-extraction test. The Phase II heat-extraction loop was successfully tested with the injection of 37,000 m/sup 3/ of cold water and production of 23,300 m/sup 3/ of hot water. Up to 10 MW/sub t/ was extracted when the production flow rate reached 0.0139 m/sup 3//s at 192/degree/C. By the end of the test, the water-loss rate had decreased to 26% and a significant portion of the injected water was recovered; 66% during the test and an additional 20% during subsequent venting. Analysis of thermal, hydraulic, geochemical, tracer, and seismic data suggests the fractured volume of the reservoir was growing throughout the test. 19 refs., 64 figs., 19 tabs.

  4. Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    Science.gov (United States)

    Ku, Jentung; Robinson, Franklin

    2016-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components in the 3K temperature range. A copper plate with attached electrical heaters was used to simulate the heat source, and heat was collected by the CLHP evaporator and transferred to the cryocooler for ultimate heat rejection. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully without pre-conditioning by simply applying power to both the capillary pump and the evaporator plate. It could adapt to rapid changes in the heat load, and reach a new steady state very quickly. Heat removal between 10mW and 140mW was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  5. Thermal Vacuum Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    Science.gov (United States)

    Ku, Jentung; Robinson, Franklin

    2016-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and to verify its ability to cool large areas or components in the 3 degrees Kelvin temperature range. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by simply applying power to both the capillary pump and the evaporator plate without pre-conditioning. It could adapt to a rapid heat load change and quickly reach a new steady state. Heat removal between 10 megawatts and 140 megawatts was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  6. PETER loop. Multifunctional test facility for thermal hydraulic investigations of PWR fuel elements; PETER Loop. Multifunktionsversuchstand zur thermohydraulischen Untersuchung von DWR Brennelementen

    Energy Technology Data Exchange (ETDEWEB)

    Ganzmann, I.; Hille, D.; Staude, U. [AREVA NP GmbH (Germany). Materials, Fluid-Structure Interaction, Plant Life Management NTCM-G

    2009-07-01

    The reliable fuel element behavior during the complete fuel cycle is one of the fundamental prerequisites of a safe and efficient nuclear power plant operation. The fuel element behavior with respect to pressure drop and vibration impact cannot be simulated by means of fluid-structure interaction codes. Therefore it is necessary to perform tests using fuel element mock-ups (1:1). AREVA NP has constructed the test facility PETER (PWR fuel element tests in Erlangen) loop. The modular construction allows maximum flexibility for any type of fuel elements. Modern measuring instrumentation for flow, pressure and vibration characterization allows the analysis of cause and consequences of thermal hydraulic phenomena. PETER loop is the standard test facility for the qualification of dynamic fuel element behavior in flowing fluid and is used for failure mode analysis.

  7. Investigation of creep by use of closed loop servo-hydraulic test system

    Science.gov (United States)

    Wu, H. C.; Yao, J. C.

    1981-01-01

    Creep tests were conducted by means of a closed loop servo-controlled materials test system. These tests are different from the conventional creep tests in that the strain history prior to creep may be carefully monitored. Tests were performed for aluminum alloy 6061-0 at 150 C and monitored by a PDP 11/04 minicomputer at a preset constant plastic-strain rate prehistory. The results show that the plastic-strain rate prior to creep plays a significant role in creep behavior. The endochronic theory of viscoplasticity was applied to describe the observed creep curves. The concepts of intrinsic time and strain rate sensitivity function are employed and modified according to the present observation.

  8. Long Duration Life Test of Propylene Glycol Water Based Thermal Fluid Within Thermal Control Loop

    Science.gov (United States)

    Le, Hung; Hill, Charles; Stephan, Ryan A.

    2010-01-01

    Evaluations of thermal properties and resistance to microbial growth concluded that 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture was desirable for use as a fluid within a vehicle s thermal control loop. However, previous testing with a commercial mixture of PG and water containing phosphate corrosion inhibitors resulted in corrosion of aluminum within the test system and instability of the test fluid. This paper describes a follow-on long duration testing and analysis of 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture with inorganic corrosion inhibitors used in place of phosphates. The test evaluates the long-term fluid stability and resistance to microbial and chemical changes

  9. A Loop-Based Apparatus for At-Speed Self-Testing

    Institute of Scientific and Technical Information of China (English)

    LI Xiaowei; Paul Y.S. Cheung

    2001-01-01

    At-speed testing using external tester requires an expensive equip ment, thus built-in self-test (BIST) is an alternative technique due to its ability to perform on-chip at-speed self-testing. The main issue in BIST for at-speed testing is to obtain high delay fault coverage with a low hardware overhead. This pa per presents an improved loop-based BIST scheme, in which a configurable MISR (multiple-input signature register) is used to generate test-pair sequences. The struc ture and operation modes of the BIST scheme are described. The topological proper ties of the state-transition-graph of the proposed BIST scheme are analyzed. Based on it, an approach to design and efficiently implement the proposed BIST scheme is developed. Experimental results on academic benchmark circuits are presented to demonstrate the effectiveness of the proposed BIST scheme as well as the design approach.

  10. Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops

    Science.gov (United States)

    Andersson, P.; Bjelkenstedt, T.; Sundén, E. Andersson; Sjöstrand, H.; Jacobsson-Svärd, S.

    Detailed knowledge of the lateral distribution of steam (void) and water in a nuclear fuel assembly is of great value for nuclear reactor operators and fuel manufacturers, with consequences for both reactor safety and economy of operation. Therefore, nuclear relevant two-phase flows are being studied at dedicated thermal-hydraulic test loop, using two-phase flow systems ranging from simplified geometries such as heated circular pipes to full scale mock-ups of nuclear fuel assemblies. Neutron tomography (NT) has been suggested for assessment of the lateral distribution of steam and water in such test loops, motivated by a good ability of neutrons to penetrate the metallic structures of metal pipes and nuclear fuel rod mock-ups, as compared to e.g. conventional X-rays, while the liquid water simultaneously gives comparatively good contrast. However, these stationary test loops require the measurement setup to be mobile, which is often not the case for NT setups. Here, it is acknowledged that fast neutrons of 14 MeV from mobile neutron generators constitute a viable option for a mobile NT system. We present details of the development of neutron tomography for this purpose at the division of Applied Nuclear Physics at Uppsala University. Our concept contains a portable neutron generator, exploiting the fusion reaction of deuterium and tritium, and a detector with plastic scintillator elements designed to achieveadequate spatial and energy resolution, all mounted in a light-weight frame without collimators or bulky moderation to allow for a mobile instrument that can be moved about the stationary thermal hydraulic test sections. The detector system stores event-to-event pulse-height information to allow for discrimination based on the energy deposition in the scintillator elements.

  11. Corrosion test for ARAA in the Experimental loop for liquid breeder

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. S.; Kim, S. K.; Lee, E. H.; Jim, H. G.; Shin, K. I.; Choi, B. G.; Lee, D. W.; Jung, Y. I. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, H. G. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Korea Atomic Energy Research Institute (KAERI) has developed the latter one to be tested in the ITER. The liquid-type TBM is one of candidate TBM for KO Demos. In this concept, helium (He) and liquid lithium (Li) were used as a coolant and a breeder, respectively. A ferritic-martensitic steel (FMS) was considered as a structural material and the Advanced Reduced Activation Alloy (ARAA) is being developed as a HCCR TBM structural material. However, according to our strategy for developing the liquid breeder TBM and its more relevant DEMO concept, liquid breeders not only considered liquid lithium but also lead-lithium (PbLi). An Experimental Loop for Liquid breeder (ELLI) was constructed for the purpose of validating the electromagnetic (EM) pump design, which designed and fabricated by ourselves; testing the effects of magneto-hydro-dynamics (MHD); and investigating the compatibility of PbLi using structural materials such as ferritic martensitic steel. The performance test on each component such as heaters, the control systems for heating the loop were performed and the characteristic tests with a magnet and the EM pump were carried out. The first corrosion tests using ELLI were performed with grade 91 FMS steel during 250 hours in 2011. In this study, the corrosion tests with developed ARAA were carried out in the ELLI loop using EM pump to investigate the corrosion behavior of ARAA, and the test results will be compared the previous corrosion tests of FMS corrosion specimens. Long term operation tests with the EM pump were carried out. During the two separate experiments, an EM pump was operated for 250 h with a speed of 0.16 m/s (0.95 Kg/s) for corrosion tests. The corrosion test for the ARAA was performed to investigate the corrosion behavior of ARAA in flowing PbLi. After micro structural observation on the ARAA surface and elemental analysis were done using a scanning electron microscope (SEM), the corrosion results of the ARAA specimens will be compared

  12. Customer interface document for the Molten Salt Test Loop (MSTL) system.

    Energy Technology Data Exchange (ETDEWEB)

    Pettit, Kathleen; Kolb, William J.; Gill, David Dennis; Briggs, Ronald D.

    2012-03-01

    The National Solar Thermal Test Facility at Sandia National Laboratories has a unique test capability called the Molten Salt Test Loop (MSTL) system. MSTL is a test capability that allows customers and researchers to test components in flowing, molten nitrate salt. The components tested can range from materials samples, to individual components such as flex hoses, ball joints, and valves, up to full solar collecting systems such as central receiver panels, parabolic troughs, or linear Fresnel systems. MSTL provides realistic conditions similar to a portion of a concentrating solar power facility. The facility currently uses 60/40 nitrate 'solar salt' and can circulate the salt at pressure up to 600psi, temperature to 585 C, and flow rate of 400-600GPM depending on temperature. The purpose of this document is to provide a basis for customers to evaluate the applicability to their testing needs, and to provide an outline of expectations for conducting testing on MSTL. The document can serve as the basis for testing agreements including Work for Others (WFO) and Cooperative Research and Development Agreements (CRADA). While this document provides the basis for these agreements and describes some of the requirements for testing using MSTL and on the site at Sandia, the document is not sufficient by itself as a test agreement. The document, however, does provide customers with a uniform set of information to begin the test planning process.

  13. Flow and Heat Transfer Tests in New Loop at 2757 kPa (400 psi)

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-13

    A helium flow and heat transfer experiment has been designed for the new helium flow loop facility at LANL. This new facility is centered on an Aerzen GM 12.4 Root’s blower, selected for operation at higher pressure, up to 2757 kPa, and mass flow rate, up to 400 g/s. This replaces the previous Tuthill PD plus 3206 blower and loop limited to 2067 kPa (300 psi) and 100 g/s. The resistively heated test piece is comprised of 7 electric heaters with embedded thermocouples. The plant design for the Mo100 to Mo99 targets requires sharp bends and geometry changes in the helium flow tube immediately before and after the target. An idealized fully developed flow configuration with straight entry and exit will be tested and compared with an option that employs rectangular tubing to make the bend at a radius consistent with and practical for the actual plant design. The current plant design, with circular tubing and a sudden contraction to rectangular just prior to target entrance, will also be tested. This requires some modification of the test piece, as described in the report.

  14. Wind tunnel testing of a closed-loop wake deflection controller for wind farm power maximization

    Science.gov (United States)

    Campagnolo, Filippo; Petrović, Vlaho; Schreiber, Johannes; Nanos, Emmanouil M.; Croce, Alessandro; Bottasso, Carlo L.

    2016-09-01

    This paper presents results from wind tunnel tests aimed at evaluating a closed- loop wind farm controller for wind farm power maximization by wake deflection. Experiments are conducted in a large boundary layer wind tunnel, using three servo-actuated and sensorized wind turbine scaled models. First, we characterize the impact on steady-state power output of wake deflection, achieved by yawing the upstream wind turbines. Next, we illustrate the capability of the proposed wind farm controller to dynamically driving the upstream wind turbines to the optimal yaw misalignment setting.

  15. Hardware in the loop simulation test platform of fuel cell backup system

    Directory of Open Access Journals (Sweden)

    Ma Tiancai

    2015-01-01

    Full Text Available Based on an analysis of voltage mechanistic model, a real-time simulation model of the proton exchange membrane (PEM fuel cell backup system is developed, and verified by the measurable experiment data. The method of online parameters identification for the model is also improved. Based on the software LabVIEW/VeriStand real-time environment and the PXI Express hardware system, the PEM fuel cell system controller hardware in the loop (HIL simulation plat-form is established. Controller simulation test results showed the accuracy of HIL simulation platform.

  16. Test Report on ISR Double-Loop, Spray-Cooled Inverter

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S [ORNL; Coomer, Chester [ORNL; Campbell, Steven L [ORNL; Wiles, Randy H [ORNL; Lowe, Kirk T [ORNL; McFee, Marshall T [ORNL

    2007-02-01

    The Isothermal Systems Research, Inc. (ISR) double-loop, two-phase spray cooling system was designed to use 85 C transmission oil to cool a heat exchanger via a second cooling loop. The heat exchanger condenses the working fluid vapor back to liquid inside a sealed enclosure to allow for continuous spray cooling of electronics. In the ORNL tests, 85 C water/ethylene/glycol (WEG), which has better thermal properties than transmission oil, was substituted for the transmission oil. Because the ISR spray-cooling system requires a second cooling loop, the final inverter might be inherently larger than inverters that do not require a second-loop cooling system. The ISR test setup did not include a dc bus capacitor. Because the insulated gate bipolar transistor (IGBT) conduction test indicated that the ISR test setup could not be properly loaded thermally, no switching tests were conducted. Therefore it was not necessary to attach external capacitors outside the test setup. During load situations not exceeding 400A, the WEG inlet temperature was higher than the WEG outlet temperature. This meant that the 85 C WEG heat exchanger was not cooling the inverter and became a thermal load to the inverter. Only when the load was higher than 400A with a higher coolant temperature and the release valve actuated did the WEG heat exchanger start to cool the 2-phase coolant. The inverter relied strongly on the cooling of the huge aluminum enclosure located inside the ventilation chamber. In a hybrid vehicle, the inverter is situated under the hood, where the dependency on cooling provided by the enclosure may become a problem. The IGBT power dissipation with both sides being spray cooled was around 34 W/cm{sup 2} at 403A, with 995W total IGBT loss at 113.5 C projected junction temperature before the release valve was actuated. The current loading could rise higher than 403 A before reaching the 125 C junction temperature limit if the pressure buildup inside the enclosure could be

  17. Assessment of High-Temperature Measurements for Use in the Gas Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    S. Curt Wilkins; Robert P. Evans

    2005-05-01

    Temperature transducers capable of control and test measurements in the 1400-1800¢ªC range in the fast neutron irradiation environment of the Gas Test Loop are evaluated. Among the instruments discussed are high-temperature thermocouples, resistance temperature detectors, ultrasonic thermometers, noise thermometers, and optical temperature sensors. High-temperature capability, behavior under irradiation, technical maturity, cost, and availability are among the key factors considered in assessing the relative merits of each measurement method. In the near term, the doped molybdenum versus niobium-zirconium alloy thermocouple is deemed to be best suited to the in-pile test and control requirements. Additional characterization of this thermocouple combination is needed to ensure confidence in its performance. Use of tungsten-rhenium alloy thermocouples, with specific disadvantages noted, constitutes the recommended back-up position.

  18. An equivalent ground thermal test method for single-phase fluid loop space radiator

    Directory of Open Access Journals (Sweden)

    Ning Xianwen

    2015-02-01

    Full Text Available Thermal vacuum test is widely used for the ground validation of spacecraft thermal control system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the normal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler (TEC array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method, a validating system has been built up and the experiments have been carried out. The results indicate that the proposed equivalent ground thermal test method can simulate the heat rejection performance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 °C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large spacecraft which employs single-phase fluid loop radiator as thermal control approach.

  19. An equivalent ground thermal test method for single-phase fluid loop space radiator

    Institute of Scientific and Technical Information of China (English)

    Ning Xianwen; Wang Yuying; Zhang Jiaxun; Liu Dongxiao

    2015-01-01

    Thermal vacuum test is widely used for the ground validation of spacecraft thermal con-trol system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the nor-mal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler (TEC) array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method, a validating system has been built up and the experiments have been carried out. The results indi-cate that the proposed equivalent ground thermal test method can simulate the heat rejection per-formance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 ?C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large space-craft which employs single-phase fluid loop radiator as thermal control approach.

  20. Open-Loop Flight Testing of COBALT Navigation and Sensor Technologies for Precise Soft Landing

    Science.gov (United States)

    Carson, John M., III; Restrepo, Caroline I.; Seubert, Carl R.; Amzajerdian, Farzin; Pierrottet, Diego F.; Collins, Steven M.; O'Neal, Travis V.; Stelling, Richard

    2017-01-01

    An open-loop flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) payload was conducted onboard the Masten Xodiac suborbital rocket testbed. The payload integrates two complementary sensor technologies that together provide a spacecraft with knowledge during planetary descent and landing to precisely navigate and softly touchdown in close proximity to targeted surface locations. The two technologies are the Navigation Doppler Lidar (NDL), for high-precision velocity and range measurements, and the Lander Vision System (LVS) for map-relative state esti- mates. A specialized navigation filter running onboard COBALT fuses the NDL and LVS data in real time to produce a very precise Terrain Relative Navigation (TRN) solution that is suitable for future, autonomous planetary landing systems that require precise and soft landing capabilities. During the open-loop flight campaign, the COBALT payload acquired measurements and generated a precise navigation solution, but the Xodiac vehicle planned and executed its maneuvers based on an independent, GPS-based navigation solution. This minimized the risk to the vehicle during the integration and testing of the new navigation sensing technologies within the COBALT payload.

  1. Geoscience Laser Altimeter System (GLAS) Instrument: Flight Loop Heat Pipe (LHP) Acceptance Thermal Vacuum Test

    Science.gov (United States)

    Baker, Charles; Butler, Dan; Ku, Jentung; Grob, Eric; Swanson, Ted; Nikitkin, Michael; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Two loop heat pipes (LHPs) are to be used for tight thermal control of the Geoscience Laser Altimeter System (GLAS) instrument, planned for flight in late 2001. The LHPs are charged with Propylene as a working fluid. One LHP will be used to transport 110 W from a laser to a radiator, the other will transport 160 W from electronic boxes to a separate radiator. The application includes a large amount of thermal mass in each LHP system and low initial startup powers. The initial design had some non-ideal flight design compromises, resulted in a less than ideal charge level for this design concept with a symmetrical secondary wick. This less than ideal charge was identified as the source of inadequate performance of the flight LHPs during the flight thermal vacuum test in October of 2000. We modified the compensation chamber design, re-built and charged the LHPs for a final LHP acceptance thermal vacuum test. This test performed March of 2001 was 100% successful. This is the last testing to be performed on the LHPs prior to instrument thermal vacuum test. This sensitivity to charge level was shown through varying the charge on a Development Model Loop Heat Pipe (DM LHP) and evaluating performance at various fill levels. At lower fills similar to the original charge in the flight units, the same poor performance was observed. When the flight units were re-designed and filled to the levels similar to the initial successful DM LHP test, the flight units also successfully fulfilled all requirements. This final flight Acceptance test assessed performance with respect to startup, low power operation, conductance, and control heater power, and steady state control. The results of the testing showed that both LHPs operated within specification. Startup on one of the LHPs was better than the other LHP because of the starter heater placement and a difference in evaporator design. These differences resulted in a variation in the achieved superheat prior to startup. The LHP with

  2. Selection of Instruments for Measuring Process Parameters of a Sodium Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, In Koo; Park, Jae Chang; Kim, Tae Joon; Lee, Tae Ho; Lee, Yong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Yang Mo [Chungnam National University, Daejeon (Korea, Republic of)

    2011-10-15

    KAERI (Korea Atomic Energy Research Institute) is constructing a sodium test facility called STELLA-1 (Sodium integrated effect TEst Loop for safety simuLation and Assessment) in which the major components for an SFR (Sodium-cooled Fast Reactor) such as heat exchangers are to be experimented. STELLA-1 includes pipes, heat exchangers, pumps, electrical heaters, tanks, and other supporting instruments and valves. These components should be in operation with the liquid sodium used as the heat transport fluid in the SFR. Based on a general review and preliminary considerations on some instrumentation methods and requirements for sodium facilities in the previous literatures, this paper describes the selected instruments, which were investigated, designed, and engineered for measuring the process variables of STELLA-1 in which the high temperature liquid sodium is flowing

  3. Preliminary Test of a small heat pipe for hybrid control rod in-core passive decay heat removal system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Ban, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-05-15

    This paper introduces 'Hybrid control rod' combining its original function and heat removal ability. The high temperature operation and high resistance of radiation should be considered to adopt the hybrid heat pipe at the in-core condition. Other design consideration is to make extra inlet parts because it has a high risk of inlet boundary failure. It means that the introduction of heat pipe system is difficult to present nuclear power plants. The other concepts are presented to out-core cooling design but it has low performance compared with in-core heat removal system. Hybrid heat pipe for in-core heat removal system suggests the solution of these problems. Ultimate objective of this research is to develop the passive emergency decay heat removal system using hybrid heat pipes targeting design bases accidents such as station black-out (SBO) and small break loss of coolant accident (SBLOCA). The purpose of this work is to confirm the performance and heat transfer behavior of hybrid heat pipe. The hybrid heat pipe has special condition for operation. Therefore, it is hard to analyze their behavior in core. Table I shows the characteristics of hybrid heat pipe and consideration for manufacturing the heat pipe.

  4. Improvement of Measurement Accuracy of Coolant Flow in a Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jintae; Kim, Jong-Bum; Joung, Chang-Young; Ahn, Sung-Ho; Heo, Sung-Ho; Jang, Seoyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, to improve the measurement accuracy of coolant flow in a coolant flow simulator, elimination of external noise are enhanced by adding ground pattern in the control panel and earth around signal cables. In addition, a heating unit is added to strengthen the fluctuation signal by heating the coolant because the source of signals are heat energy. Experimental results using the improved system shows good agreement with the reference flow rate. The measurement error is reduced dramatically compared with the previous measurement accuracy and it will help to analyze the performance of nuclear fuels. For further works, out of pile test will be carried out by fabricating a test rig mockup and inspect the feasibility of the developed system. To verify the performance of a newly developed nuclear fuel, irradiation test needs to be carried out in the research reactor and measure the irradiation behavior such as fuel temperature, fission gas release, neutron dose, coolant temperature, and coolant flow rate. In particular, the heat generation rate of nuclear fuels can be measured indirectly by measuring temperature variation of coolant which passes by the fuel rod and its flow rate. However, it is very difficult to measure the flow rate of coolant at the fuel rod owing to the narrow gap between components of the test rig. In nuclear fields, noise analysis using thermocouples in the test rig has been applied to measure the flow velocity of coolant which circulates through the test loop.

  5. Waste Heat Recovery from the Advanced Test Reactor Secondary Coolant Loop

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen

    2012-11-01

    This study investigated the feasibility of using a waste heat recovery system (WHRS) to recover heat from the Advanced Test Reactor (ATR) secondary coolant system (SCS). This heat would be used to preheat air for space heating of the reactor building, thus reducing energy consumption, carbon footprint, and energy costs. Currently, the waste heat from the reactor is rejected to the atmosphere via a four-cell, induced-draft cooling tower. Potential energy and cost savings are 929 kW and $285K/yr. The WHRS would extract a tertiary coolant stream from the SCS loop and pump it to a new plate and frame heat exchanger, from which the heat would be transferred to a glycol loop for preheating outdoor air supplied to the heating and ventilation system. The use of glycol was proposed to avoid the freezing issues that plagued and ultimately caused the failure of a WHRS installed at the ATR in the 1980s. This study assessed the potential installation of a new WHRS for technical, logistical, and economic feasibility.

  6. Real-Time Hardware-in-the-Loop Laboratory Testing for Multisensor Sense and Avoid Systems

    Directory of Open Access Journals (Sweden)

    Giancarmine Fasano

    2013-01-01

    Full Text Available This paper focuses on a hardware-in-the-loop facility aimed at real-time testing of architectures and algorithms of multisensor sense and avoid systems. It was developed within a research project aimed at flight demonstration of autonomous non-cooperative collision avoidance for Unmanned Aircraft Systems. In this framework, an optionally piloted Very Light Aircraft was used as experimental platform. The flight system is based on multiple-sensor data integration and it includes a Ka-band radar, four electro-optical sensors, and two dedicated processing units. The laboratory test system was developed with the primary aim of prototype validation before multi-sensor tracking and collision avoidance flight tests. System concept, hardware/software components, and operating modes are described in the paper. The facility has been built with a modular approach including both flight hardware and simulated systems and can work on the basis of experimentally tested or synthetically generated scenarios. Indeed, hybrid operating modes are also foreseen which enable performance assessment also in the case of alternative sensing architectures and flight scenarios that are hardly reproducible during flight tests. Real-time multisensor tracking results based on flight data are reported, which demonstrate reliability of the laboratory simulation while also showing the effectiveness of radar/electro-optical fusion in a non-cooperative collision avoidance architecture.

  7. Carbon dioxide removal system for closed loop atmosphere revitalization, candidate sorbents screening and test results

    Science.gov (United States)

    Mattox, E. M.; Knox, J. C.; Bardot, D. M.

    2013-05-01

    Due to the difficulty and expense it costs to resupply manned-spacecraft habitats, a goal is to create a closed loop atmosphere revitalization system, in which precious commodities such as oxygen, carbon dioxide, and water are continuously recycled. Our aim is to test other sorbents for their capacity for future spacecraft missions, such as on the Orion spacecraft, or possibly lunar or Mars mission habitats to see if they would be better than the zeolite sorbents on the 4-bed molecular sieve. Some of the materials being tested are currently used for other industry applications. Studying these sorbents for their specific spacecraft application is different from that for applications on earth because in space, there are certain power, mass, and volume limitations that are not as critical on Earth. In manned-spaceflight missions, the sorbents are exposed to a much lower volume fraction of CO2 (0.6% volume CO2) than on Earth. LiLSX was tested for its CO2 capacity in an atmosphere like that of the ISS. Breakthrough tests were run to establish the capacities of these materials at a partial pressure of CO2 that is seen on the ISS. This paper discusses experimental results from benchmark materials, such as results previously obtained from tests on Grade 522, and the forementioned candidate materials for the Carbon Dioxide Removal Assembly (CDRA) system.

  8. Study on the requirement for the fuel test loop performance in the HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Chul; Kim, Hark Rho

    2000-06-01

    The requirement of the FTL (Fuel Test Loop) performance were investigated to reaffirm the technical feasibility of the FTL facility which is in consideration to install at the HANARO. LH hole in the reflector region and OR3 in the outer core region are considered as candidate sites for the IPS (In-Pile Section) for the analysis purpose. The achievable linear power at test fuel pin(s) and neutron flux levels at the cladding are analyzed in the IPS, which accommodates CANDU or PWR test fuel. The enrichment of test fuels is assumed as natural uranium for CANDU and 3.5% or 5% for PWR. The test fuel configuration is bundle or 7-pin in LH hole but 1-pin in OR site. For the CANDU test fuel, the target linear power of 60kW/m can not be achieved for all cases. For the PWR test fuel, the target linear power of 40kW/m is obtained at fuels located in the direction of the core for only the case of 5% bundle irradiation. From a sensitivity study, the linear power at test fuel is expected to increase at least 30% of the present results if the core bumup effect, optimization of the ratio of fuel-to-moderator number density, etc., are considered in the detail design. Thus, the linear power for PWR fuel is expected to reach the target value, and that for CANDU fuel will reach the target value if enriched fuel is used. The fast neutron flux at the test fuel cladding is estimated for most cases to be lower than one-third of the target value of 10{sup 1}4 n/cm{sup 2}-sec and expected not to reach the target value.

  9. Testing the Master Constraint Programme for Loop Quantum Gravity I. General Framework

    CERN Document Server

    Dittrich, B; Dittrich, Bianca; Thiemann, Thomas

    2004-01-01

    Recently the Master Constraint Programme for Loop Quantum Gravity (LQG) was proposed as a classically equivalent way to impose the infinite number of Wheeler -- DeWitt constraint equations in terms of a single Master Equation. While the proposal has some promising abstract features, it was until now barely tested in known models. In this series of five papers we fill this gap, thereby adding confidence to the proposal. We consider a wide range of models with increasingly more complicated constraint algebras, beginning with a finite dimensional, Abelean algebra of constraint operators which are linear in the momenta and ending with an infinite dimensional, non-Abelean algebra of constraint operators which closes with structure functions only and which are not even polynomial in the momenta. In all these models we apply the Master Constraint Programme successfully, however, the full flexibility of the method must be exploited in order to complete our task. This shows that the Master Constraint Programme has a w...

  10. Design and performance test of miniature capillary pumped loop for electronics cooling

    Institute of Scientific and Technical Information of China (English)

    万珍平; 皮丕辉; 付永清; 汤勇

    2008-01-01

    Considering two characteristics of compact heat dissipation room and high heat flux, a novel miniature capillary pumped loop (MCPL) for electronics cooling was proposed. MCPL consists of evaporator, condenser, vapor and liquid line dissipates heat by boiling and condensation of working fluids with no extra power consumption. Working fluid circulation is ensured by vapor pressure and capillary head. Saturated wick screens vapor and liquid, and ensures one-way flow of working fluid with no extra valve. In order to promote heat dissipation capacity of MCPL, the intensified boiling and condensation structures are embedded into evaporator and condenser respectively, which are useful to increasing boiling and condensation efficiency. Startup and run characteristics are tested by experiments in the condition of different power inputs and working fluids. MCPL is capable of dissipating 80 W of thermal energy and keeping the bottom substrate temperature of evaporator at 80 ℃.

  11. Cyber-Physical Test Platform for Microgrids: Combining Hardware, Hardware-in-the-Loop, and Network-Simulator-in-the-Loop

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Austin; Chakraborty, Sudipta; Wang, Dexin; Singh, Pawan; Cui, Qiang; Yang, Liuqing; Suryanarayanan, Siddharth

    2016-11-14

    This paper presents a cyber-physical testbed, developed to investigate the complex interactions between emerging microgrid technologies such as grid-interactive power sources, control systems, and a wide variety of communication platforms and bandwidths. The cyber-physical testbed consists of three major components for testing and validation: real time models of a distribution feeder model with microgrid assets that are integrated into the National Renewable Energy Laboratory's (NREL) power hardware-in-the-loop (PHIL) platform; real-time capable network-simulator-in-the-loop (NSIL) models; and physical hardware including inverters and a simple system controller. Several load profiles and microgrid configurations were tested to examine the effect on system performance with increasing channel delays and router processing delays in the network simulator. Testing demonstrated that the controller's ability to maintain a target grid import power band was severely diminished with increasing network delays and laid the foundation for future testing of more complex cyber-physical systems.

  12. Closed-Loop Acoustic Control of Reverberant Room for Satellite Environmental Testing

    Science.gov (United States)

    Janssens, Karl; Bianciardi, Fabio; Sabbatini, Danilo; Debille, Jan; Carrella, Alex

    2012-07-01

    The full satellite acoustic test is an important milestone in a satellite launch survivability verification campaign. This test is required to verify the satellite’s mechanical design against the high-level acoustic loads induced by the launch vehicle during the atmospheric flight. During the test, the satellite is subjected to a broadband diffuse acoustic field, reproducing the pressure levels observed during launch. The excitation is in most cases provided by a combination of horns for the low frequencies and noise generators for the higher frequencies. Acoustic control tests are commonly performed in reverberant rooms, controlling the sound pressure levels in third octave bands over the specified target spectrum. This paper discusses an automatic feedback control system for acoustic control of large reverberation rooms for satellite environmental testing. The acoustic control system consists of parallel third octave PI (Proportional Integral) feedback controllers that take the reverberation characteristics of the room into consideration. The drive output of the control system is shaped at every control step based on the comparison of the average third octave noise spectrum, measured from a number of microphones in the test room, with the target spectrum. Cross-over filters split the output drive into band- limited signals to feed each of the horns. The control system is realized in several steps. In the first phase, a dynamic process model is developed, including the non-linear characteristics of the horns and the reverberant properties of the room. The model is identified from dynamic experiments using system identification techniques. In the next phase, an adequate control strategy is designed which is capable of reaching the target spectrum in the required time period without overshoots. This control strategy is obtained from model-in-the-loop (MIL) simulations, evaluating the performance of various potential strategies. Finally, the proposed strategy is

  13. Multi-Purpose Thermal Hydraulic Loop: Advanced Reactor Technology Integral System Test (ARTIST) Facility for Support of Advanced Reactor Technologies

    Energy Technology Data Exchange (ETDEWEB)

    James E. O' Brien; Piyush Sabharwall; SuJong Yoon

    2001-11-01

    Effective and robust high temperature heat transfer systems are fundamental to the successful deployment of advanced reactors for both power generation and non-electric applications. Plant designs often include an intermediate heat transfer loop (IHTL) with heat exchangers at either end to deliver thermal energy to the application while providing isolation of the primary reactor system. In order to address technical feasibility concerns and challenges a new high-temperature multi-fluid, multi-loop test facility “Advanced Reactor Technology Integral System Test facility” (ARTIST) is under development at the Idaho National Laboratory. The facility will include three flow loops: high-temperature helium, molten salt, and steam/water. Details of some of the design aspects and challenges of this facility, which is currently in the conceptual design phase, are discussed

  14. The Impact of Curriculum Looping on Standardized Literacy and Mathematics Test Scores

    Science.gov (United States)

    Nessler, Ralph D.

    2010-01-01

    There is a lack of research on the practice of curriculum looping and student achievement. The purpose of this study was to examine academic achievement between students in looping classes and those in nonlooping classes. The theoretical model of this study was based on the social cognitive theory of Bandura and Maslow's hierarchy of needs theory.…

  15. The Impact of Curriculum Looping on Standardized Literacy and Mathematics Test Scores

    Science.gov (United States)

    Nessler, Ralph D.

    2010-01-01

    There is a lack of research on the practice of curriculum looping and student achievement. The purpose of this study was to examine academic achievement between students in looping classes and those in nonlooping classes. The theoretical model of this study was based on the social cognitive theory of Bandura and Maslow's hierarchy of needs theory.…

  16. Phase-locked-loop interferometry applied to aspheric testing with a computer-stored compensator.

    Science.gov (United States)

    Servin, M; Malacara, D; Rodriguez-Vera, R

    1994-05-01

    A recently developed technique for continuous-phase determination of interferograms with a digital phase-locked loop (PLL) is applied to the null testing of aspheres. Although this PLL demodulating scheme is also a synchronous or direct interferometric technique, the separate unwrapping process is not explicitly required. The unwrapping and the phase-detection processes are achieved simultaneously within the PLL. The proposed method uses a computer-generated holographic compensator. The holographic compensator does not need to be printed out by any means; it is calculated and used from the computer. This computer-stored compensator is used as the reference signal to phase demodulate a sample interferogram obtained from the asphere being tested. Consequently the demodulated phase contains information about the wave-front departures from the ideal computer-stored aspheric interferogram. Wave-front differences of ~ 1 λ are handled easily by the proposed PLL scheme. The maximum recorded frequency in the template's interferogram as well as in the sampled interferogram are assumed to be below the Nyquist frequency.

  17. Experimental investigations with a carbonate looping test facility with 1 MW thermal power; Experimentelle Untersuchungen an einer Carbonate Looping Versuchsanlage mit 1 MW thermischer Leistung

    Energy Technology Data Exchange (ETDEWEB)

    Galloy, Alexander

    2014-02-20

    Carbonate looping is a process for separation of CO{sub 2} from flue gases of fossil-fired power plants. For further examination of this process a test facility with a thermal power of 1 MW has been designed, erected, commissioned and operated. This plant was operated for several hundred hours in different modes. CO{sub 2} could be separated from a synthetic flue gas. Separation was possible within continuous and discontinuous mode of operation. Within this work the state of the art, the test facility and measurement results e.g. temperature curves, pressure curves and gas concentrations are presented. Additionally, the influence of these parameters on the CO{sub 2} separation is discussed.

  18. Order 1/N2 test of the Maldacena conjecture : cancellation of the one-loop Weyl anomaly.

    OpenAIRE

    Mansfield, Paul; Nolland, David

    2000-01-01

    We test the Maldacena conjecture for type IIB String Theory/ N=4 Yang-Mills by calculating the one-loop corrections in the bulk theory to the Weyl anomaly of the boundary CFT when the latter is coupled to a Ricci-flat metric. The contributions cancel within each supermultiplet, in agreement with the conjecture.

  19. Very High Temperature Test of Alloy617 Compact Heat Exchanger in Helium Experimental Loop

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Soo; Park, Byung-Ha; Kim, Eung-Seon [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The Intermediate Heat eXchanger (IHX) is a key-challenged high temperature component which determines the efficiency and the economy of VHTR system. Heat generated in the VHTR fuel block is transferred from the VHTR to the intermediate loop through IHX. In the present, the shell-helical tube heat exchanger is generally used as IHX of the helium cooled reactor. Recently, a Printed Circuit Heat Exchanger (PCHE) is one of the candidates for the IHX in a VHTR because its operation temperature and pressure are larger than any other compact heat exchanger types. These test results show that there is no problem in operation of HELP at the very high temperature experimental condition and the alloy617 compact heat exchanger can be operated in the very high temperature condition above 850℃. In the future, the high temperature structural analysis will be studied to estimate the thermal stress during transient and thermal shock condition. The conditions and evaluation standard for the alloy 617 diffusion bonding will be minutely studied to fabricate the large-scale PCHE for the high temperature condition.

  20. Mockup tests for developing the CARR-CNS with a two-phase thermo-siphon loop

    Institute of Scientific and Technical Information of China (English)

    DU She-Jiao; BI Qin-Cheng; CHEN Ting-Kuan; FENG Quan-Ke; LI Xiao-Ming

    2004-01-01

    The cold neutron source (CNS) is a facility to increase cold neutrons by scattering thermal neutrons in liquid hydrogen or deuterium around 20 K. For extracting a stable cold neutron flux fiom the CNS, the liquid quantity in the moderator cell should be maintained stably against disturbance of nuclear heating. The China Institute of Atomic Energy (CIAE) is now constructing the China Advanced Research Reactor (CARR: 60 MW), and designing the CARR-CNS with a two-phase thermo-siphon loop consisting of a condenser, two moderator transfer tubes and an annular cylindrical moderator cell. The mock-up tests were carried out using a full-scale loop with Freon-113, for validating the self-regulating characteristics of the loop, the void fraction less than 20% in the liquid hydrogen of the moderator cell, and the requirements for establishing the condition under which the inner shell has only vapor. The density ratio of liquid to vapor and the volumetric evaporation rate due to heat load are kept the same as those in normal operation of the CARR-CNS. The results show that the loop has the self-regulating characteristics and the inner shell contains only vapor, while the outer shell liquid. The local void fraction in the liquid increases with increasing of the loop pressure.

  1. Heuristic Approach of Automated Test Data Generation for Program having Array of Different Dimensions and Loops with Variable Number of Iteration

    OpenAIRE

    Hitesh Tahbildar; Bichitra Kalita

    2010-01-01

    Normally, program execution spends most of the time on loops. Automated test data generation devotes special attention to loops for better coverage. Automated test data generation for programs having loops with variable number of iteration and variable length array is a challenging problem. It is so because the number of paths may increase exponentially with the increase of array size for some programming constructs, like merge sort. We propose a method that finds heuristic for different type...

  2. Development and hardware-in-the-loop test of a guidance, navigation and control system for on-orbit servicing

    Science.gov (United States)

    Benninghoff, Heike; Rems, Florian; Boge, Toralf

    2014-09-01

    The rendezvous phase is one of the most important phases in future orbital servicing missions. To ensure a safe approach to a non-cooperative target satellite, a guidance, navigation and control system which uses measurements from optical sensors like cameras was designed and developed. During ground-based rendezvous, stability problems induced by delayed position measurements can be compensated by using a specially adapted navigation filter. Within the VIBANASS (VIsion BAsed NAvigation Sensor System) test campaign, hardware-in-the-loop tests on the terrestrial, robotic based facility EPOS 2.0 were performed to test and verify the developed guidance, navigation and control algorithms using real sensor measurements. We could demonstrate several safe rendezvous test cases in a closed loop mode integrating the VIBANASS camera system and the developed guidance, navigation and control system to a dynamic rendezvous simulation.

  3. A Two-loop Test of Buscher's T-duality, 1

    CERN Document Server

    Horváth, Z; Palla, L; Horvath, Zalan; Karp, Robert L.; Palla, Laszlo

    2000-01-01

    We study the two loop quantum equivalence of sigma models related by Buscher's T-duality transformation. The computation of the two loop perturbative free energy density is performed in the case of a certain deformation of the SU(2) principal sigma model, and its T-dual, using dimensional regularization and the geometric sigma model perturbation theory. We obtain agreement between the free energy density expressions of the two models.

  4. FY 1993 progress report on the ANS thermal-hydraulic test loop operation and results

    Energy Technology Data Exchange (ETDEWEB)

    Siman-Tov, M.; Felde, D.K.; Farquharson, G. [and others

    1994-07-01

    The Thermal-Hydraulic Test Loop (THTL) is an experimental facility constructed to support the development of the Advanced Neutron Source Reactor (ANSR) at Oak Ridge National Laboratory (ORNL). Highly subcooled heavy-water coolant flows vertically upward at a very high mass flux of almost 27 MG/m{sup 2}-s. In a parallel fuel plate configuration as in the ANSR, the flow is subject to a potential excursive static-flow instability that can very rapidly lead to flow starvation and departure from nucleate boiling (DNB) in the ``hot channel``. The current correlations and experimental data bases for flow excursion (FE) and critical heat flux (CHF) seldom evaluate the specific combination of ANSR operating parameters. The THTL facility was designed and built to provide known thermal-hydraulic (T/H) conditions for a simulated full-length coolant subchannel of the ANS reactor core, thus facilitating experimental determination of FE and CHF thermal limits under expected ANSR T/H conditions. A series of FE tests with water flowing vertically upward was completed over a nominal heat flux range of 6 to 17 MW/m{sup 2}, a mass flux range of 8 to 28 Mg/m{sup 2}-s, an exit pressure range of 1.4 to 2.1 MPa, and an inlet temperature range of 40 to 50 C. FE experiments were also conducted using as ``soft`` a system as possible to secure a true FE phenomena (actual secondary burnout). True DNB experiments under similar conditions were also conducted. To the author`s knowledge, no other FE data have been reported in the literature to date that dover such a combination of conditions of high mass flux, high heat flux, and moderately high pressure.

  5. A New Built-in Self Test Scheme for Phase-Locked Loops Using Internal Digital Signals

    Science.gov (United States)

    Kim, Youbean; Kim, Kicheol; Kim, Incheol; Kang, Sungho

    Testing PLLs (phase-locked loops) is becoming an important issue that affects both time-to-market and production cost of electronic systems. Though a PLL is the most common mixed-signal building block, it is very difficult to test due to internal analog blocks and signals. In this paper, we propose a new PLL BIST (built-in self test) using the distorted frequency detector that uses only internal digital signals. The proposed BIST does not need to load any analog nodes of the PLL. Therefore, it provides an efficient defect-oriented structural test scheme, reduced area overhead, and improved test quality compared with previous approaches.

  6. Power-Hardware-In-the-Loop (PHIL) Test of VSC-based HVDC connection for Offshore Wind Power Plants (WPPs)

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Cha, Seung-Tae; Wu, Qiuwei;

    2011-01-01

    This paper presents a power-hardware-in-the-loop (PHIL) test for an offshore wind power plant (WPP) interconnected to the onshore grid by a VSC-based HVDC connection. The intention of the PHIL test is to verify the control coordination between the plant side converter of the HVDC connection...... the successful control coordination between the WPP and the plant side VSC converter of the HVDC connection of the WPP....

  7. Heuristic Approach of Automated Test Data Generation for Program having Array of Different Dimensions and Loops with Variable Number of Iteration

    CERN Document Server

    Tahbildar, Hitesh

    2010-01-01

    Normally, program execution spends most of the time on loops. Automated test data generation devotes special attention to loops for better coverage. Automated test data generation for programs having loops with variable number of iteration and variable length array is a challenging problem. It is so because the number of paths may increase exponentially with the increase of array size for some programming constructs, like merge sort. We propose a method that finds heuristic for different types of programming constructs with loops and arrays. Linear search, Bubble sort, merge sort, and matrix multiplication programs are included in an attempt to highlight the difference in execution between single loop, variable length array and nested loops with one and two dimensional arrays. We have used two parameters/heuristics to predict the minimum number of iterations required for generating automated test data. They are longest path level (kL) and saturation level (kS). The proceedings of our work includes the instrum...

  8. PDCI Wide-Area Damping Control: PSLF Simulations of the 2016 Open and Closed Loop Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Wilches Bernal, Felipe [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pierre, Brian Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schoenwald, David A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trudnowski, Daniel J. [Montana Tech of the Univ. of Montana, Butte, MT (United States); Donnelly, Matthew K. [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2017-03-01

    To demonstrate and validate the performance of the wide-are a damping control system, the project plans to conduct closed-loop tests on the PDCI in summer/fall 2016. A test plan details the open and closed loop tests to be conducted on the P DCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the result s from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases.

  9. Testing an Ansatz for the Leading Secular Loop Corrections from Quantum Gravity during Inflation

    CERN Document Server

    Basu, S

    2016-01-01

    It is widely believed that the leading secular loop corrections from quantum gravity can be subsumed into a coordinate redefinition. Hence the apparent infrared logarithm corrections to any quantity would be just the result of taking the expectation value of the tree order quantity at the transformed coordinates in the graviton vacuum. We term this the Transformation Ansatz and we compare its predictions against explicit one loop computations in Maxwell + Einstein and Dirac + Einstein on de Sitter background. In each case the ansatz fails.

  10. Testing an ansatz for the leading secular loop corrections from quantum gravity during inflation

    Science.gov (United States)

    Basu, S.; Woodard, R. P.

    2016-10-01

    It is widely believed that the leading secular loop corrections from quantum gravity can be subsumed into a coordinate redefinition. Hence the apparent infrared logarithm corrections to any quantity would be just the result of taking the expectation value of the tree order quantity at the transformed coordinates in the graviton vacuum. We term this the transformation ansatz and we compare its predictions against explicit one loop computations in Maxwell + Einstein and Dirac + Einstein on de Sitter background. In each case the ansatz fails.

  11. Implementation of a hardware-in-the-loop facility for student test and evaluation

    Science.gov (United States)

    Mobley, Scott B.; Ballard, Gary; Brindley, Ryan; Gareri, Jeff

    2007-04-01

    Hardware-in-the-Loop (HWIL) test facilities offer the highest degree of system functional verification and performance evaluation outside of the actual operational environment. The design and analysis of HWIL simulators involves the coordinated efforts of numerous engineering fields, whose professionals possess the technical expertise, analytical skills, and insight regarding cross-discipline collaborative relationships which foster successful simulation development. As system complexity continues to increase, and as programmatic requirements allow for shorter simulation development schedules, the existing knowledge base associated with legacy HWIL simulation development will play a key role in the preparation, readiness, and efficiency of future HWIL engineering professionals. As a result, it is crucial that basic HWIL methods and concepts be specified in a formal, academic sense, and that realistic test facilities are made available to allow potential HWIL engineering students the opportunity to become acclimated to basic HWIL components and design considerations. To address this need, the United States Army Space and Missile Defense Command (SMDC), in coordination with the Auburn University Department of Aerospace Engineering, has funded an initiative to perform initial development of a graduate-level HWIL simulation option, including the provision of a functioning HWIL simulation facility located at the university. This facility, modeled after a conceptual ballistic missile interceptor, will possess the major elements of a HWIL simulation including a Six-Degree-of-Freedom (6-DOF) simulation of the missile dynamics, an electro-optical (EO) sensor implementation, a flight motion simulator (FMS), a scene generation system, and an in-band image projection system. Architectural implementations and distributed simulation elements will be modeled after existing U.S. Army missile simulation concepts. In concert with this activity, an academic emphasis on HWIL

  12. Advanced neutron source reactor thermal-hydraulic test loop facility description

    Energy Technology Data Exchange (ETDEWEB)

    Felde, D.K.; Farquharson, G.; Hardy, J.H.; King, J.F.; McFee, M.T.; Montgomery, B.H.; Pawel, R.E.; Power, B.H.; Shourbaji, A.A.; Siman-Tov, M.; Wood, R.J.; Yoder, G.L.

    1994-02-01

    The Thermal-Hydraulic Test Loop (THTL) is a facility for experiments constructed to support the development of the Advanced Neutron Source Reactor (ANSR) at Oak Ridge National Laboratory. The ANSR is both cooled and moderated by heavy water and uses uranium silicide fuel. The core is composed of two coaxial fuel-element annuli, each of different diameter. There are 684 parallel aluminum-clad fuel plates (252 in the inner-lower core and 432 in the outer-upper core) arranged in an involute geometry that effectively creates an array of thin rectangular flow channels. Both the fuel plates and the coolant channels are 1.27 mm thick, with a span of 87 mm (lower core), 70 mm (upper core), and 507-mm heated length. The coolant flows vertically upwards at a mass flux of 27 Mg/m{sup 2}s (inlet velocity of 25 m/s) with an inlet temperature of 45{degrees}C and inlet pressure of 3.2 MPa. The average and peak heat fluxes are approximately 6 and 12 MW/m{sup 2}, respectively. The availability of experimental data for both flow excursion (FE) and true critical heat flux (CHF) at the conditions applicable to the ANSR is very limited. The THTL was designed and built to simulate a full-length coolant subchannel of the core, allowing experimental determination of thermal limits under the expected ANSR thermal-hydraulic conditions. For these experimental studies, the involute-shaped fuel plates of the ANSR core with the narrow 1.27-mm flow gap are represented by a narrow rectangular channel. Tests in the THTL will provide both single- and two-phase thermal-hydraulic information. The specific phenomena that are to be examined are (1) single-phase heat-transfer coefficients and friction factors, (2) the point of incipient boiling, (3) nucleate boiling heat-transfer coefficients, (4) two-phase pressure-drop characteristics in the nucleate boiling regime, (5) flow instability limits, and (6) CHF limits.

  13. The RADAR Test Methodology: Evaluating a Multi-Task Machine Learning System with Humans in the Loop

    Science.gov (United States)

    2006-10-01

    Learning System with Humans in the Loop 7 subject in the form of static web pages easily accessible from the subject’s home page (Figure 2, top and...middle). Other static web content included a conference planning manual (complete with documentation of standard task constraints), a PDF of the...that I can make arrangements! Thanks, you’re the best! Kim Figure 2. Static web and vendor portal examples The RADAR Test Methodology

  14. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    Science.gov (United States)

    Polzin, Kurt A.; Godfroy, Thomas J.

    2008-01-01

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

  15. Experimental analysis of control loops with different delay times in the supply air system of a radiator test rig

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yongpan; Zhao, Tianyi [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Zhang, Jili; Lu, Zhen [School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, Hui [Beijing Siemens Cerberus Electronics Ltd, Beijing 100085 (China)

    2011-01-15

    The test rig of low-temperature hot-water radiator is a typical multi-input multi-output (MIMO) thermal system with large time delay. Aiming at the control of the supply air temperature and the temperature of the environmental chamber in the test rig, the paper carries out the fuzzy control experiments and PI control experiments based on adjusting the electric heater in the supply air system, in which there are two control loops with various delay time. The experiments researched two types of fuzzy control methods which are the basic fuzzy control (BFC), and the self-organizing rules fuzzy control (SORFC) with zero initial control rules. For the control loop of supply air temperature with short delay time, PI control performs better with fast convergence speed and small overshoot than the BFC and the SORFC. The convergence speed of the BFC method is lower than other two control methods. For the control loop of chamber temperature with long delay time, the SORFC has a satisfied control performance with less overshoot and stable error than the BFC and PI control. (author)

  16. CHARACTERIZATIONS ON THE THIXOTROPY-LOOP TESTS USING UCM MODEL WITH A RATE-TYPE KINETIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    Shu-xin Huang; Chuan-jing Lu

    2006-01-01

    The theoretical characterizations on the triangular-form thixotropy-loop tests of an LDPE melt (PE-FSB23D022/Q200) were conducted in the present paper by using a new thixotropy model, which is constituted by the upper convected Maxwell model and a rate-type kinetic equation. The new thixotropic Maxwell model can partially describe well three reported thixotropy-loop experiments by comparison with the previous calculations of the variant form of the thixotropy-type Huang model. It is noted that the stress deviations between the experiments and the predictions of the new thixotropic Maxwell model are much slighter than those deviations obtained by using the variant Huang model at the same condition, although both models include five parameters. The constitution of the new thixotropic Maxwell model is more reasonable than that of the variant Huang model.

  17. Control-Relevant Identification Test Design for Open-Loop Experiment

    Institute of Scientific and Technical Information of China (English)

    张立群; 邵惠鹤

    2004-01-01

    An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are derived based on the asymptotic theory. The signal is used for the open loop experiment. The design constraint is the power of the process signal or the process input signal. The results give guideline for identification application.

  18. Hardware in the Loop Testing of an Iodine-Fed Hall Thruster

    Science.gov (United States)

    Polzin, Kurt A.; Peeples, Steven R.; Cecil, Jim; Lewis, Brandon L.; Molina Fraticelli, Jose C.; Clark, James P.

    2015-01-01

    chamber (it is under 10(exp -6) torr at -75 C), making it possible to 'cryopump' the propellant with lower-cost recirculating refrigerant-based systems as opposed to using liquid nitrogen or low temperature gaseous helium cryopanels. In the present paper, we describe testing performed using an iodine-fed 200 W Hall thruster mounted to a thrust stand and operated in conjunction with MSFCs Small Projects Rapid Integration and Test Environment (SPRITE) Portable Hardware In the Loop (PHIL) hardware. This work is performed in support of the iodine satellite (iSAT) project, which aims to fly a 200-W iodine-fed thruster on a 12-U CubeSat. The SPRITE PHIL hardware allows a given vehicle to do a checkout of its avionics algorithm by allowing it to monitor and feed data to simulated sensors and effectors in a digital environment. These data are then used to determine the attitude of the vehicle and a separate computer is used to interpret the data set and visualize it using a 3D graphical interface. The PHIL hardware allows the testing of the vehicles bus by providing 'real' hardware interfaces (in the case of this test a real RS422 bus) and specific components can be modeled to show their interactions with the avionics algorithm (e.g. a thruster model). For the iSAT project the PHIL is used to visualize the operating cycle of the thruster and the subsequent effect this thrusting has on the attitude of the satellite over a given period of time. The test is controlled using software running on an Andrews Space Cortex 160 flight computer. This computer is the current baseline for a full iSAT mission. While the test could be conducted with a lab computer and software, the team chose to exercise the propulsion system with a representative CubeSat-class computer. For purposes of this test, the "flight" software monitored the propulsion and PPU systems, controlled operation of the thruster, and provided thruster state data to the PHIL simulation. Commands to operate the thruster were

  19. Tests and limit analysis of loop connections between precast concrete elements loaded in tension

    DEFF Research Database (Denmark)

    Jørgensen, Henrik Brøner; Hoang, Linh Cao

    2013-01-01

    is influenced by important design parameters such as the overlapping length of the U-bars, the spacing between adjacent U-bars and the amount of transverse reinforcement. Knowledge about the parameters that have an effect on the failure of the joint concrete is important in order to avoid this failure mode...... by yielding of the U-bars or by failure in the joint concrete. Only few investigations of the case of concrete failure can be found in the literature. This paper presents an experimental program dedicated to study loop connections critical to concrete failure. The results show that the ultimate load...

  20. Advanced Photovoltaic Inverter Functionality using 500 kW Power Hardware-in-Loop Complete System Laboratory Testing: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Mather, B. A.; Kromer, M. A.; Casey, L.

    2013-01-01

    With the increasing penetration of distribution connected photovoltaic (PV) systems, more and more PV developers and utilities are interested in easing future PV interconnection concerns by mitigating some of the impacts of PV integration using advanced PV inverter controls and functions. This paper describes the testing of a 500 kW PV inverter using Power Hardware-in-Loop (PHIL) testing techniques. The test setup is described and the results from testing the inverter in advanced functionality modes, not commonly used in currently interconnected PV systems, are presented. PV inverter operation under PHIL evaluation that emulated both the DC PV array connection and the AC distribution level grid connection are shown for constant power factor (PF) and constant reactive power (VAr) control modes. The evaluation of these modes was completed under varying degrees of modeled PV variability.

  1. Testing of a controller for an ETO-based STATCOM through controller hardware-in-the-loop simulation

    DEFF Research Database (Denmark)

    Langston, J.; Qi, L.; Steurer, M.

    2009-01-01

    The testing of a controller for a proposed 10 MVA STATCOM through hardware-in-the-loop experimentation is described in this paper. The electrical environment into which the STATCOM is to be inserted, including a significant portion of the utility network and a nearby wind farm are simulated using...... a large-scale digital real time electromagnetic transients simulator. The STATCOM controller is interfaced to the simulation, providing firing pulses to the simulated STATCOM and receiving feedback of system voltages and currents. Notional wind speed data is used to simulate realistic behavior of the wind...

  2. Space Suit Portable Life Support System (PLSS) 2.0 Human-in-the-Loop (HITL) Testing

    Science.gov (United States)

    Watts, Carly; Vogel, Matthew

    2016-01-01

    The space suit Portable Life Support System (PLSS) 2.0 represents the second integrated prototype developed and tested to mature a design that uses advanced technologies to reduce consumables, improve robustness, and provide additional capabilities over the current state of the art. PLSS 2.0 was developed in 2012, with extensive functional evaluations and system performance testing through mid-2014. In late 2014, PLSS 2.0 was integrated with the Mark III space suit in an ambient laboratory environment to facilitate manned testing, designated PLSS 2.0 Human-in-the-Loop (HITL) testing, in which the PLSS prototype performed the primary life support functions, including suit pressure regulation, ventilation, carbon dioxide control, and cooling of the test subject and PLSS avionics. The intent of this testing was to obtain subjective test subject feedback regarding qualitative aspects of PLSS 2.0 performance such as thermal comfort, sounds, smells, and suit pressure fluctuations due to the cycling carbon dioxide removal system, as well as to collect PLSS performance data over a range of human metabolic rates from 500-3000 Btu/hr. Between October 27 and December 18, 2014, nineteen two-hour simulated EVA test points were conducted in which suited test subjects walked on a treadmill to achieve a target metabolic rate. Six test subjects simulated nominal and emergency EVA conditions with varied test parameters including metabolic rate profile, carbon dioxide removal control mode, cooling water temperature, and Liquid Cooling and Ventilation Garment (state of the art or prototype). The nineteen test points achieved more than 60 hours of test time, with 36 hours accounting for simulated EVA time. The PLSS 2.0 test article performed nominally throughout the test series, confirming design intentions for the advanced PLSS. Test subjects' subjective feedback provided valuable insight into thermal comfort and perceptions of suit pressure fluctuations that will influence future

  3. Numerical Modeling of a Thermal-Hydraulic Loop and Test Section Design for Heat Transfer Studies in Supercritical Fluids

    Science.gov (United States)

    McGuire, Daniel

    A numerical tool for the simulation of the thermal dynamics of pipe networks with heat transfer has been developed with the novel capability of modeling supercritical fluids. The tool was developed to support the design and deployment of two thermal-hydraulic loops at Carleton University for the purpose of heat transfer studies in supercritical and near-critical fluids. First, the system was characterized based on its defining features; the characteristic length of the flow path is orders of magnitude larger than the other characteristic lengths that define the system's geometry; the behaviour of the working fluid in the supercritical thermodynamic state. An analysis of the transient thermal behaviour of the model's domains is then performed to determine the accuracy and range of validity of the modeling approach for simulating the transient thermal behaviour of a thermal-hydraulic loop. Preliminary designs of three test section geometries, for the purpose of heat transfer studies, are presented in support of the overall design of the Carleton supercritical thermal-hydraulic loops. A 7-rod-bundle, annular and tubular geometries are developed with support from the new numerical tool. Materials capable of meeting the experimental requirements while operating in supercritical water are determined. The necessary geometries to satisfy the experimental goals are then developed based on the material characteristics and predicted heat transfer behaviour from previous simulation results. An initial safety analysis is performed on the test section designs, where they are evaluated against the ASME Boiler, Pressure Vessel, and Pressure Piping Code standard, required for safe operation and certification.

  4. One-loop tests of the supersymmetric higher spin AdS4/CFT3 correspondence

    Science.gov (United States)

    Pang, Yi; Sezgin, Ergin; Zhu, Yaodong

    2017-01-01

    We compute one-loop free energy for D =4 Vasiliev higher spin gravities based on Konstein-Vasiliev algebras h u (m ;n |4 ) , h o (m ;n |4 ) , or h u s p (m ;n |4 ) and subject to higher spin-preserving boundary conditions, which are conjectured to be dual to the U (N ) , O (N ) or U S p (N ) singlet sectors, respectively, of free conformal field theories (CFTs) on the boundary of AdS4 . Ordinary supersymmetric higher spin theories appear as special cases of Konstein-Vasiliev theories, when the corresponding higher spin algebra contains O S p (N |4 ) as a subalgebra. In AdS4 with an S3 boundary, we use a regularization scheme for individual spins that employs their character such that the subsequent sum over all spins is finite, thereby avoiding the need for additional regularization. We find that the contribution of the infinite tower of bulk fermions vanishes. As a result, the free energy is the sum of those which arise in type A and type B models with internal symmetries, the known mismatch between the bulk and boundary free energies for type B model persists, and ordinary supersymmetric higher spin theories exhibit the mismatch as well. The only models that have a match are type A models with internal symmetries, corresponding to n =0 . The matching requires identification of the inverse Newton constant GN-1 with N plus a proper integer as was found previously for special cases. In AdS4 with an S1×S2 boundary, the bulk one-loop free energies match those of the dual free CFTs for arbitrary m and n . We also show that a supersymmetric double-trace deformation of free CFT based on O S p (1 |4 ) does not contribute to the O (N0) free energy, as expected from the bulk.

  5. Morphing Wing-Tip Open Loop Controller and its Validation During Wind Tunnel Tests at the IAR-NRC

    Directory of Open Access Journals (Sweden)

    Mohamed Sadok GUEZGUEZ

    2016-09-01

    Full Text Available In this project, a wing tip of a real aircraft was designed and manufactured. This wing tip was composed of a wing and an aileron. The wing was equipped with a composite skin on its upper surface. This skin changed its shape (morphed by use of 4 electrical in-house developed actuators and 32 pressure sensors. These pressure sensors measure the pressures, and further the loads on the wing upper surface. Thus, the upper surface of the wing was morphed using these actuators with the aim to improve the aerodynamic performances of the wing-tip. Two types of ailerons were designed and manufactured: one aileron is rigid (non-morphed and one morphing aileron. This morphing aileron can change its shape also for the aerodynamic performances improvement. The morphing wing-tip internal structure is designed and manufactured, and is presented firstly in the paper. Then, the modern communication and control hardware are presented for the entire morphing wing tip equipped with actuators and sensors having the aim to morph the wing. The calibration procedure of the wing tip is further presented, followed by the open loop controller results obtained during wind tunnel tests. Various methodologies of open loop control are presented in this paper, and results obtained were obtained and validated experimentally through wind tunnel tests.

  6. Summary Report on Gamma Radiolysis of TBP/n-dodecane in the Presence of Nitric Acid Using the Radiolysis/Hydrolysis Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Dean R. Peterman; Bruce J. Mincher; Catherine L. Riddle; Richard D. Tillotson

    2010-08-01

    Design and installation has been completed for a state-of-the-art radiolysis/hydrolysis test loop system. The system is used to evaluate the effects of gamma radiolysis and acid hydrolysis on the stability and performance of solvent extraction process solvents. The test loop is comprised of two main sections; the solvent irradiation and hydrolysis loop and the solvent reconditioning loop. In the solvent irradiation and hydrolysis loop, aqueous and organic phases are mixed and circulated through a gamma irradiator until the desired absorbed dose is achieved. Irradiation of the mixed phases is more representative of actual conditions in a solvent extraction process. Additionally, the contact of the organic phase with the aqueous phase will subject the solvent components to hydrolysis. This hydrolysis can be accelerated by controlling the system at an elevated temperature. At defined intervals, the organic from the irradiation/hydrolysis loop will be transferred to the solvent reconditioning loop where the solvent is contacted with scrub, strip, and solvent wash solutions which simulate process flowsheet conditions. These two processes are repeated until the total desired dose is achieved. Since all viable solvent extraction components in an advanced fuel cycle must exhibit high radiolytic and hydrolytic stability, this test loop is not limited to any one solvent system but is applicable to all systems of interest. Also, the test loop is not limited to testing of process flowsheets. It is also a valuable tool in support of fundamental research on newly identified extractants/modifiers and the impact of gamma radiation on their stability in a dynamic environment. The investigation of the radiolysis of a TBP/n-dodecane process solvent in contact with aqueous nitric acid has been performed. These studies were intended to confirm/optimize the operability of the test loop system. Additionally, these data are directly applicable to numerous other solvent extraction

  7. One Loop Tests of Supersymmetric Higher Spin $AdS_4/CFT_3$

    CERN Document Server

    Pang, Yi; Zhu, Yaodong

    2016-01-01

    We compute one loop free energy for D=4 Vasiliev higher spin gravities based on Konstein-Vasiliev algebras hu(m;n|4), ho(m;n|4) or husp(m;n|4) and subject to higher spin preserving boundary conditions, which are conjectured to be dual to the U(N), O(N) or USp(N) singlet sectors, respectively, of free CFTs on the boundary of $AdS_4$. Ordinary supersymmetric higher spin theories appear as special cases of Konstein-Vasiliev theories, when the corresponding higher spin algebra contains $OSp({\\cal N}|4)$ as subalgebra. In $AdS_4$ with $S^3$ boundary, we use a modified spectral zeta function method, which avoids the ambiguity arising from summing over infinite number of spins. We find that the contribution of the infinite tower of bulk fermions vanishes. As a result, the free energy is the sum of those which arise in type A and type B models with internal symmetries, the known mismatch between the bulk and boundary free energies for type B model persists, and ordinary supersymmetric higher spin theories exhibit the...

  8. A closed-loop automatic control system for high-intensity acoustic test systems.

    Science.gov (United States)

    Slusser, R. A.

    1973-01-01

    Sound at sound pressure levels in the range from 130 to 160 dB is used in the investigation. Random noise is passed through a series of parallel filters, generally 1/3-octave wide. A basic automatic system is investigated because of preadjustment inaccuracies and high costs found in a study of a typical manually controlled acoustic testing system. The unit described has been successfully used in automatic acoustic tests in connection with the spacecraft tests for the Mariner 1971 program.

  9. Design, Development, and Testing of a UAV Hardware-in-the-Loop Testbed for Aviation and Airspace Prognostics Research

    Science.gov (United States)

    Kulkarni, Chetan; Teubert, Chris; Gorospe, George; Burgett, Drew; Quach, Cuong C.; Hogge, Edward

    2016-01-01

    The airspace is becoming more and more complicated, and will continue to do so in the future with the integration of Unmanned Aerial Vehicles (UAVs), autonomy, spacecraft, other forms of aviation technology into the airspace. The new technology and complexity increases the importance and difficulty of safety assurance. Additionally, testing new technologies on complex aviation systems & systems of systems can be very difficult, expensive, and sometimes unsafe in real life scenarios. Prognostic methodology provides an estimate of the health and risks of a component, vehicle, or airspace and knowledge of how that will change over time. That measure is especially useful in safety determination, mission planning, and maintenance scheduling. The developed testbed will be used to validate prediction algorithms for the real-time safety monitoring of the National Airspace System (NAS) and the prediction of unsafe events. The framework injects flight related anomalies related to ground systems, routing, airport congestion, etc. to test and verify algorithms for NAS safety. In our research work, we develop a live, distributed, hardware-in-the-loop testbed for aviation and airspace prognostics along with exploring further research possibilities to verify and validate future algorithms for NAS safety. The testbed integrates virtual aircraft using the X-Plane simulator and X-PlaneConnect toolbox, UAVs using onboard sensors and cellular communications, and hardware in the loop components. In addition, the testbed includes an additional research framework to support and simplify future research activities. It enables safe, accurate, and inexpensive experimentation and research into airspace and vehicle prognosis that would not have been possible otherwise. This paper describes the design, development, and testing of this system. Software reliability, safety and latency are some of the critical design considerations in development of the testbed. Integration of HITL elements in

  10. University of Maryland at College Park (UMCP) 2 x 4 Loop Test Facility: Annual report for 1985

    Energy Technology Data Exchange (ETDEWEB)

    DiMarzo, M.; Hsu, Y.Y.; Lin, W.K.; Massoud, M.; Cunno, C.J.; Munno, F.J.; Pertmer, G.; Popp, M.; Sallet, D.W.; Wang, Z.Y.

    1987-03-01

    The efforts for the year 1985 of the investigators of University of Maryland on UMCP 2 x 4 LOOP facility is presented in this annual report to USNRC. These efforts include: additional work on the facility; theoretical investigation; and experimental investigation. The report is prepared in three chapters and seven appendices. A brief description of the facility including the final design details are presented in chapter one. Chapter two includes the theoretical basis for the experimental investigation which is followed by chapter three which contains the details of experiments, test results, and final conclusions. The appendices contain additional details about the topics discussed in the chapters. The name of the contributor(s), for clarification, is shown in the parenthesis following the title of each section.

  11. Non-Parametric, Closed-Loop Testing of Autonomy in Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase I program aims to develop new methods to support safety testing for integration of Unmanned Aircraft Systems into the National Airspace (NAS) with...

  12. Hardware in the loop testing and evaluation of seaborne search radars

    CSIR Research Space (South Africa)

    Strydom, JJ

    2012-09-01

    Full Text Available as the texture component of sea clutter. The shorter wavelengths are responsible for the speckle component of sea clutter. The comparative figures below show the “spikiness” of the sea clutter measured during low and high sea state conditions using an X... test environment is also more repeatable, thus allowing several radars to be evaluated under very similar conditions. DRFM based test environments enable the characterisation of a radar system’s target detection, target tracking...

  13. Reduced-scale water test of natural circulation for decay heat removal in loop-type sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, T., E-mail: murakami@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 1646 Abiko, Chiba (Japan); Eguchi, Y., E-mail: eguchi@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 1646 Abiko, Chiba (Japan); Oyama, K., E-mail: kazuhiro_oyama@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 2-34-17 Jinguumae, Shibuya, Tokyo (Japan); Watanabe, O., E-mail: osamu4_watanabe@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 2-34-17 Jinguumae, Shibuya, Tokyo (Japan)

    2015-07-15

    Highlights: • The natural circulation characteristics of a loop-type SFR are examined by a water test. • The performance of decay heat removal system is evaluated using a similarity law. • The effects of flow deviation in the parallel piping of a primary loop are clarified. • The reproducibility of the natural circulation test is confirmed. - Abstract: Water tests of a loop-type sodium-cooled fast reactor have been conducted to physically evaluate the natural circulation characteristics. The water test apparatus was manufactured as a 1/10-scale mock-up of the Japan Sodium-Cooled Fast Reactor, which adopts a decay heat removal system (DHRS) utilizing natural circulation. Tests simulating a variety of events and operation conditions clarified the thermal hydraulic characteristics and core-cooling performance of the natural circulation in the primary loop. Operation conditions such as the duration of the pump flow coast-down and the activation time of the DHRS affect the natural circulation characteristics. A long pump flow coast-down cools the upper plenum of the reactor vessel (RV). This causes the loss of the buoyant force in the RV. The test result indicates that a long pump flow coast-down tends to result in a rapid increase in the core temperature because of the loss of the buoyant force. The delayed activation of the DHRS causes a decrease in the natural circulation flow rate and a temperature rise in the RV. Flow rate deviation and a reverse flow appear in the parallel cold-leg piping in some events, which cause thermal stratification in the cold-leg piping. The DHRS prevents the core temperature from fatally rise even for the most severe design-basis event, in which sodium leakage in a secondary loop of the DHRS and the opening failure of a single damper of the air cooler occur simultaneously. In the water test for the case of siphon break in the primary loop, which is one of the design extension conditions, a circulation flow consisting of ascendant

  14. NOMAGE4 activities 2011, Part II, Supercritical water loop

    DEFF Research Database (Denmark)

    Vierstraete, Pierre; Van Nieuwenhove, Rudi; Lauritzen, Bent

    The supercritical water reactor (SCWR) is one of the six different reactor technologies selected for research and development under the Generation IV program. Several countries have shown interest to this concept but up to now, there exist no in-pile facilities to perform the required material...... and fuel tests. Working on this direction, the Halden Reactor Project has started an activity in collaboration with Risoe-DTU (with Mr. Rudi Van Nieuwenhove as the project leader) to study the feasibility of a SCW loop in the Halden Reactor, which is a Heavy Boiling Water Reactor (HBWR). The ultimate goal...... of the project is to design a loop allowing material and fuel test studies at significant mass flow with in-core instrumentation and chemistry control possibilities. The present report focusses on the main heat exchanger required for such a loop in the Halden Reactor. The goal of this heat exchanger is to assure...

  15. The Self-Calibration Test of flowmeter installed in STELLA(Sodium Integral Effect Test Loop for Safety Simulation and Assessment) facility

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Minhwan; Jeong, Ji-Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The objective of this study is to describe the procedure of the self-calibration test for the flowmeters and to analyze the result of the test. In this work, the test procedure of the self-calibration of two flowmeters (FT-101, FT-102) installed in STELLA facility was described and the test result was analyzed. In regard to the long-term SFR development plan, a large-scale sodium thermal-hydraulic test project is being progressed by KAERI. This project is called STELLA (Sodium Integral Effect Test Loop for Safety Simulation and Assessment), and it is proceeding by adopting the QA (Quality Assurance) program. Due to the specificity of an experiment using sodium(Na) categorized as Class 3(pyrophoric material and water-prohibiting substance) by the Safety Control of Dangerous Substances Act, it is necessary to apply QA in consideration of the sodium experiment environment in certain parts. The one of them is about calibration of measuring instrument such as a flowmeter, thermocouple and pressure gauge. It is described in the QAP (Quality Assurance Procedures) of KAERI that calibration work should be conducted in accordance with self-calibration procedures in a special case where conventional calibration is not practicable. The calibration of two flowmeters (FT-101, FT-102) installed in STELLA facility is the typical example. As a result of test, it was confirmed that the flowmeters meet the pass criterion. Therefore, it was concluded that the flowmeters maintain instrument capacity a year ago.

  16. Intergranular Corrosion of Low Cr Ferritic Stainless Steel 429 Evaluated by the Optimized Double Loop Electrochemical Potentiokinetic Reactivation Test

    Directory of Open Access Journals (Sweden)

    Xiao-lei Li

    2015-01-01

    Full Text Available Intergranular corrosion (IGC of Nb-Ti stabilized ferritic stainless steel (FSS 429 was investigated using the double loop electrochemical potentiokinetic reactivation (DL-EPR test combined with the microstructure observation. The results indicated that the optimized DL-EPR test condition for FSS 429 was the solution of 0.5 M H2SO4 + 0.0001 M KSCN with a scanning rate of 100 mV/min at 30°C. Based on this condition, the specimens aging at 400–700°C for different duration were tested and a time-temperature-sensitization (TTS curve for FSS 429 was obtained, which reveals the sensitization nose was located around 550°C. The critical Ir/Ia value was determined to be about 3% above which IGC occurred. After aging treatment, Cr depletion zone was detected using energy dispersive spectroscopy (EDS, most possibly due to Cr segregation around intergranular TiC and NbC.

  17. Studies of the steam generator degraded tubes behavior on BRUTUS test loop

    Energy Technology Data Exchange (ETDEWEB)

    Chedeau, C.; Rassineux, B. [EDF/DER/MTC, Moret Sur Loing (France); Flesch, B. [EDF/EPN/DMAINT, Paris (France)] [and others

    1997-04-01

    Studies for the evaluation of steam generator tube bundle cracks in PWR power plants are described. Global tests of crack leak rates and numerical calculations of crack opening area are discussed in some detail. A brief overview of thermohydraulic studies and the development of a mechanical probabilistic design code is also given. The COMPROMIS computer code was used in the studies to quantify the influence of in-service inspections and maintenance work on the risk of a steam generator tube rupture.

  18. Loop-mediated isothermal amplification (LAMP) test for specific and rapid detection of Brucella abortus in cattle.

    Science.gov (United States)

    Karthik, K; Rathore, Rajesh; Thomas, Prasad; Arun, T R; Viswas, K N; Agarwal, R K; Manjunathachar, H V; Dhama, Kuldeep

    2014-01-01

    Brucella abortus, the major causative agent of abortion in cattle and a zoonotic pathogen, needs to be diagnosed at an early stage. Loop-mediated isothermal amplification (LAMP) test is easy to perform and also promising to be adapted at field level. To develop a LAMP assay for specific and rapid detection of B. abortus from clinical samples of cattle. LAMP primers were designed targeting BruAb2_0168 region using specific software tool and LAMP was optimized. The developed LAMP was tested for its specificity with 3 Brucella spp. and 11 other non-Brucella spp. Sensitivity of the developed LAMP was also carried out with known quantity of DNA. Cattle whole blood samples and aborted fetal stomach contents were collected and used for testing with developed LAMP assay and results were compared with polymerase chain reaction (PCR). The developed LAMP assay works at 61 °C for 60 min and the detection limit was observed to be 100-fold more than the conventional PCR that is commonly used for diagnosis of B. abortus. Clinical sensitivity and specificity of the developed LAMP assay was 100% when compared with Rose Bengal plate test and standard tube agglutination test. SYB® green dye I was used to visualize the result with naked eye. The novelty of the developed LAMP assay for specifically detecting B. abortus infection in cattle along with its inherent rapidness and high sensitivity can be employed for detecting this economically important pathogen of cattle at field level as well be exploited for screening of human infections.

  19. Diagnostic Accuracy of the Overlapping Infinity Loops, Wire Cube, and Clock Drawing Tests for Cognitive Impairment in Mild Cognitive Impairment and Dementia

    Directory of Open Access Journals (Sweden)

    Thammanard Charernboon

    2017-01-01

    Full Text Available Purpose. To investigate the diagnostic accuracy of the overlapping infinity loops, wire cube, and clock drawing tests (CDT in the detection of mild cognitive impairment (MCI and dementia. Method. The participants were 60 normal controls (NC, 35 patients with MCI, and 47 patients with mild dementia. Results. The results illustrate that infinity loops, cube, or CDT were not able to discriminate between NC and MCI groups. In dementia detection, the CDT had the highest diagnostic accuracy (sensitivity 76.6% and specificity 87.4% followed by infinity loops (sensitivity 63.8% and specificity 91.6% and cube (sensitivity 93.6% and specificity 46.3%. Conclusion. This study demonstrates that the three drawing tests are sensitive detectors of dementia but not MCI.

  20. Diagnostic Accuracy of the Overlapping Infinity Loops, Wire Cube, and Clock Drawing Tests for Cognitive Impairment in Mild Cognitive Impairment and Dementia.

    Science.gov (United States)

    Charernboon, Thammanard

    2017-01-01

    Purpose. To investigate the diagnostic accuracy of the overlapping infinity loops, wire cube, and clock drawing tests (CDT) in the detection of mild cognitive impairment (MCI) and dementia. Method. The participants were 60 normal controls (NC), 35 patients with MCI, and 47 patients with mild dementia. Results. The results illustrate that infinity loops, cube, or CDT were not able to discriminate between NC and MCI groups. In dementia detection, the CDT had the highest diagnostic accuracy (sensitivity 76.6% and specificity 87.4%) followed by infinity loops (sensitivity 63.8% and specificity 91.6%) and cube (sensitivity 93.6% and specificity 46.3%). Conclusion. This study demonstrates that the three drawing tests are sensitive detectors of dementia but not MCI.

  1. Closed-loop neuro-robotic experiments to test computational properties of neuronal networks.

    Science.gov (United States)

    Tessadori, Jacopo; Chiappalone, Michela

    2015-03-02

    Information coding in the Central Nervous System (CNS) remains unexplored. There is mounting evidence that, even at a very low level, the representation of a given stimulus might be dependent on context and history. If this is actually the case, bi-directional interactions between the brain (or if need be a reduced model of it) and sensory-motor system can shed a light on how encoding and decoding of information is performed. Here an experimental system is introduced and described in which the activity of a neuronal element (i.e., a network of neurons extracted from embryonic mammalian hippocampi) is given context and used to control the movement of an artificial agent, while environmental information is fed back to the culture as a sequence of electrical stimuli. This architecture allows a quick selection of diverse encoding, decoding, and learning algorithms to test different hypotheses on the computational properties of neuronal networks.

  2. Dynamic closed-loop test for real-time drift angle adjustment of space camera on the Earth

    Science.gov (United States)

    Hu, Jun; Cao, Xiaotao; Wang, Dong; Wu, Weiping; Xu, Shuyan

    2010-10-01

    In order to eliminate the influence of aircraft attitude angle to the image quality of space camera, and assure that the drift angle of space camera could be accurately adjusted at the orbit, a novel closed-loop test method is provided for real-time drift angle adjustment of space camera on the Earth. A long focal length dynamic aim generator is applied to simulate the image motion and the variety drift angle, and to detect the precision of the image motion compensation machinery and the capability of the drift angle control system. The computer system is used to control the dynamic aim generator, accomplish the data processing, transmit and receive the data information. The seamless connection and the data transmission between the aim generator and the aircraft simulation devices are constituted. The command, parameter and drift angle data transmitted by the simulation devices are received by the space camera at the real time, then the photos are taken and the draft angle is adjusted simultaneously. It is shown that the drift angle can be accurately tracked by the space camera at the real time, and the detective method satisfies the test requirement.

  3. A Continuous-Adaptive DDRx Interface with Flexible Round-Trip-Time and Full Self Loop-Backed AC Test

    Science.gov (United States)

    Haraguchi, Masaru; Osawa, Tokuya; Yamazaki, Akira; Morishima, Chikayoshi; Morihara, Toshinori; Morooka, Yoshikazu; Okuno, Yoshihiro; Arimoto, Kazutami

    This paper describes new DDRx SDRAM interface architecture suitable for system-on-chip (SOC) implementation. Our test chip fabricated in a 90-nm CMOS process adopts three key schemes and achieves 960 Mb/s/pin operations with 32 bits width. One of new schemes is to suppress timing skew with rising-edge signal transmission I/O circuit and look-up table type impedance calibration circuit. DQS round-trip-time, propagation delay from rising edge of system clock in SOC to arrival of DQS at input PAD of SOC during read operation, becomes longer than one clock cycle time as for DDR2 interface and beyond. Flexible DQS round-trip-time scheme can allow wide range up to N/2 cycles in N bits burst read operation. In addition, full self loop-backed test scheme is also proposed to measure AC timing parameters without high-end tester. The architecture reported in this paper can be continuously adaptive to realize higher data-rate and cost-efficient DDRx-SDRAM interface for various kinds of SOC.

  4. High-Temperature Structural Analysis of a Small-Scale PHE Prototype under the Test Condition of a Small-Scale Gas Loop

    Directory of Open Access Journals (Sweden)

    Kee-Nam Song

    2012-01-01

    Full Text Available A process heat exchanger (PHE is a key component for transferring the high-temperature heat generated from a very high-temperature reactor (VHTR to a chemical reaction for the massive production of hydrogen. The Korea Atomic Energy Research Institute has designed and assembled a small-scale nitrogen gas loop for a performance test on VHTR components and has manufactured a small-scale PHE prototype made of Hastelloy-X alloy. A performance test on the PHE prototype is underway in the gas loop, where different kinds of pipelines connecting to the PHE prototype are tested for reducing the thermal stress under the expansion of the PHE prototype. In this study, to evaluate the high-temperature structural integrity of the PHE prototype under the test condition of the gas loop, a realistic and effective boundary condition imposing the stiffness of the pipelines connected to the PHE prototype was suggested. An equivalent spring stiffness to reduce the thermal stress under the expansion of the PHE prototype was computed from the bending deformation and expansion of the pipelines connected to the PHE. A structural analysis on the PHE prototype was also carried out by imposing the suggested boundary condition. As a result of the analysis, the structural integrity of the PHE prototype seems to be maintained under the test condition of the gas loop.

  5. rf deflector design of the CLIC test facility CTF3 delay loop and beam loading effect analysis

    Directory of Open Access Journals (Sweden)

    David Alesini

    2009-03-01

    Full Text Available Beam injection and extraction in the delay loop of the CLIC Test Facility 3 (CTF3 for recombination of adjacent bunch trains, is performed by a specially designed rf deflector. A standing wave structure has been chosen for this purpose. Three possible solutions have been investigated, and a comparative analysis is presented. All of them satisfy the essential requirements of the system up to the maximum foreseen energy with the existing klystron. The final design of the rf deflector consists of two identical cavities connected to the rf power source through a hybrid junction that equally splits the power and isolates the klystron from reflections. The rf deflector design, the results of electromagnetic simulations, and the low level rf measurements are illustrated. The impact of beam loading in the rf deflectors on the transverse beam dynamics is also analyzed. The general expression of the single passage transverse wakefield is obtained and a dedicated tracking code has been written to study the multibunch multiturn effects. A complete analysis for different machine parameters and injection errors is presented and discussed. These numerical simulations indicate a tolerable beam emittance growth due to the transverse wakefield in the rf deflectors.

  6. Autism and genius: is there a link? The involvement of central brain loops and hypotheses for functional testing.

    Science.gov (United States)

    Boso, M; Emanuele, E; Prestori, Francesca; Politi, P; Barale, F; D'Angelo, E

    2010-01-01

    Mental processing is the product of the huge number of synaptic interactions that occur in the brain. It is easier to understand how brain functions can deteriorate than how they might be boosted. Lying at the border between the humanities, cognitive science and neurophysiology, some mental diseases offer new angles on this problematic issue. Despite their social deficits, autistic subjects can display unexpected and extraordinary skills in numerous fields, including music, the arts, calculation and memory. The advanced skills found in a subgroup of people with autism may be explained by their special mental functioning, in particular by their weak central coherence, one of the pivotal characteristics of the disorder. As a result of the increasing interest in autistic talent, there has recently emerged a tendency to screen any eccentric artist or scientist for traits of the autistic spectrum. Following this trend, we analyze the eccentricity of the popular pianist Glenn Gould and briefly discuss the major functional hypotheses on autistic hyperfunctioning, advancing proposals for functional testing. In particular, the potential involvement of rhythm-entrained systems and cerebro-cerebellar loops opens up new perspectives for the investigation of autistic disorders and brain hyperfunctioning.

  7. Evaluation by the Double Loop Electrochemical Potentiokinetic Reactivation Test of Aged Ferritic Stainless Steel Intergranular Corrosion Susceptibility

    Science.gov (United States)

    Sidhom, H.; Amadou, T.; Braham, C.

    2010-12-01

    An experimental design method was used to determine the effect of factors that significantly affect the response of the double loop-electrochemical potentiokinetic reactivation (DL-EPR) test in controlling the susceptibility to intergranular corrosion (IGC) of UNS S43000 (AISI 430) ferritic stainless steel. The test response is expressed in terms of the reactivation/activation current ratio ( I r / I a pct). Test results analysed by the analysis of variance (ANOVA) method show that the molarity of the H2SO4 electrolyte and the potential scanning rate have a more significant effect on the DL-EPR test response than the temperature and the depassivator agent concentration. On the basis of these results, a study was conducted in order to determine the optimal operating conditions of the test as a nondestructive technique for evaluating IGC resistance of ferritic stainless steel components. Three different heat treatments are considered in this study: solution annealing (nonsensitized), aging during 3 hours at 773 K (500 °C) (slightly sensitized), and aging during 2 hours at 873 K (600 °C) (highly sensitized). The aim is to find the operating conditions that simultaneously ensure the selectivity of the attack (intergranular and chromium depleted zone) and are able to detect the effect of low dechromization. It is found that a potential scanning rate of 2.5 mV/s in an electrolyte composed of H2SO4 3 M solution without depassivator, at a temperature around 293 K (20 °C), is the optimal operating condition for the DL-EPR test. Using this condition, it is possible to assess the degree of sensitization (DOS) to the IGC of products manufactured in ferritic stainless steels rapidly, reliably, and quantitatively. A time-temperature-start of sensitization (TTS) diagram for the UNS S43000 (France Inox, Villepinte, France) stainless steel was obtained with acceptable accuracy by this method when the IGC sensitization criterion was set to I r / I a > 1 pct. This diagram is in

  8. Loop-Mediated Isothermal Amplification for Laboratory Confirmation of Buruli Ulcer Disease-Towards a Point-of-Care Test.

    Directory of Open Access Journals (Sweden)

    Marcus Beissner

    2015-11-01

    Full Text Available As the major burden of Buruli ulcer disease (BUD occurs in remote rural areas, development of point-of-care (POC tests is considered a research priority to bring diagnostic services closer to the patients. Loop-mediated isothermal amplification (LAMP, a simple, robust and cost-effective technology, has been selected as a promising POC test candidate. Three BUD-specific LAMP assays are available to date, but various technical challenges still hamper decentralized application. To overcome the requirement of cold-chains for transport and storage of reagents, the aim of this study was to establish a dry-reagent-based LAMP assay (DRB-LAMP employing lyophilized reagents.Following the design of an IS2404 based conventional LAMP (cLAMP assay suitable to apply lyophilized reagents, a lyophylization protocol for the DRB-LAMP format was developed. Clinical performance of cLAMP was validated through testing of 140 clinical samples from 91 suspected BUD cases by routine assays, i.e. IS2404 dry-reagent-based (DRB PCR, conventional IS2404 PCR (cPCR, IS2404 qPCR, compared to cLAMP. Whereas qPCR rendered an additional 10% of confirmed cases and samples respectively, case confirmation and positivity rates of DRB-PCR or cPCR (64.84% and 56.43%; 100% concordant results in both assays and cLAMP (62.64% and 52.86% were comparable and there was no significant difference between the sensitivity of the assays (DRB PCR and cPCR, 86.76%; cLAMP, 83.82%. Likewise, sensitivity of cLAMP (95.83% and DRB-LAMP (91.67% were comparable as determined on a set of 24 samples tested positive in all routine assays.Both LAMP formats constitute equivalent alternatives to conventional PCR techniques. Provided the envisaged availability of field friendly DNA extraction formats, both assays are suitable for decentralized laboratory confirmation of BUD, whereby DRB-LAMP scores with the additional advantage of not requiring cold-chains. As validation of the assays was conducted in a third

  9. Multi-Megawatt-Scale Power-Hardware-in-the-Loop Interface for Testing Ancillary Grid Services by Converter-Coupled Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Koralewicz, Przemyslaw J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wallen, Robert B [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-07-26

    Power-hardware-in-the-loop (PHIL) is a simulation tool that can support electrical systems engineers in the development and experimental validation of novel, advanced control schemes that ensure the robustness and resiliency of electrical grids that have high penetrations of low-inertia variable renewable resources. With PHIL, the impact of the device under test on a generation or distribution system can be analyzed using a real-time simulator (RTS). PHIL allows for the interconnection of the RTS with a 7 megavolt ampere (MVA) power amplifier to test multi-megawatt renewable assets available at the National Wind Technology Center (NWTC). This paper addresses issues related to the development of a PHIL interface that allows testing hardware devices at actual scale. In particular, the novel PHIL interface algorithm and high-speed digital interface, which minimize the critical loop delay, are discussed.

  10. Closed-loop control of zebrafish response using a bioinspired robotic-fish in a preference test.

    Science.gov (United States)

    Kopman, Vladislav; Laut, Jeffrey; Polverino, Giovanni; Porfiri, Maurizio

    2013-01-06

    In this paper, we study the response of zebrafish to a robotic-fish whose morphology and colour pattern are inspired by zebrafish. Experiments are conducted in a three-chambered instrumented water tank where a robotic-fish is juxtaposed with an empty compartment, and the preference of live subjects is scored as the mean time spent in the vicinity of the tank's two lateral sides. The tail-beating of the robotic-fish is controlled in real-time based on feedback from fish motion to explore a spectrum of closed-loop systems, including proportional and integral controllers. Closed-loop control systems are complemented by open-loop strategies, wherein the tail-beat of the robotic-fish is independent of the fish motion. The preference space and the locomotory patterns of fish for each experimental condition are analysed and compared to understand the influence of real-time closed-loop control on zebrafish response. The results of this study show that zebrafish respond differently to the pattern of tail-beating motion executed by the robotic-fish. Specifically, the preference and behaviour of zebrafish depend on whether the robotic-fish tail-beating frequency is controlled as a function of fish motion and how such closed-loop control is implemented.

  11. Abschlussbericht des Projekts SiLEST (Software in teh Loop for Embedded Software Test) in der BMBF-Forschungsoffensive "Software Engineering 2006"

    OpenAIRE

    Maibaum, Olaf; Herrmann, Anita; Schumann, Holger; Berres, Axel; Serway, Roland; Rebeschieß, Sven; Gühmann, Clemens; Liebezeit, Thomas; Bazarsuren, Uzmee; Montenegro, Sergio; Geppert, Jens; Ionescu, Iona

    2008-01-01

    Der Bericht beschreibt einen Testprozess für die Durchführung von Model-, Software-, Processor- und Hardware-in-the-Loop-Tests mit der Möglichkeit der Fehlerinjektion. Der Testprozess ist weitestgehend automatisiert und das Werkzeug zur Testautomatisierung ist offen für die Einbindung in unterschiedliche Testinfrastrukturen und Testmanagementsystemen. Ein besonderes Augenmerk wurde dabei auf die Wiederverwendung von Fehlerfällen und Simulationsumgebungen gelegt. Der Testprozess wurde exemplar...

  12. Abschlussbericht des Projekts SiLEST (Software in teh Loop for Embedded Software Test) in der BMBF-Forschungsoffensive "Software Engineering 2006"

    OpenAIRE

    Maibaum, Olaf; Herrmann, Anita; Schumann, Holger; Berres, Axel; Serway, Roland; Rebeschieß, Sven; Gühmann, Clemens; Liebezeit, Thomas; Bazarsuren, Uzmee; Montenegro, Sergio; Geppert, Jens; Ionescu, Iona

    2008-01-01

    Der Bericht beschreibt einen Testprozess für die Durchführung von Model-, Software-, Processor- und Hardware-in-the-Loop-Tests mit der Möglichkeit der Fehlerinjektion. Der Testprozess ist weitestgehend automatisiert und das Werkzeug zur Testautomatisierung ist offen für die Einbindung in unterschiedliche Testinfrastrukturen und Testmanagementsystemen. Ein besonderes Augenmerk wurde dabei auf die Wiederverwendung von Fehlerfällen und Simulationsumgebungen gelegt. Der Testprozess wurde exemplar...

  13. Research on DRA outdoor buried test loop and transient model%减阻剂室外埋地评价环道及瞬态模型

    Institute of Scientific and Technical Information of China (English)

    黄启玉; 王培伟; 刘丽飞

    2013-01-01

    The evaluation experiment of DRA is mainly conducted in indoor test loop.Indoor test loop has a small diameter and length,the flowrate of the oil in indoor test loops differs considerably from that in actual pipelines.In view of these shortages of indoor test loop,an outdoor test loop of 300 m-long with a diameter of 159 mm is designed and built,in which the flowrate of oil is more close to that in actual pipelines.Using high-pressure nitrogen as source power,the unit has high accuracy pressure transducers and high frequency pressure transducers along the test section,ultrasonic flow meter at the outlet of the test section,and high pressure tank and normal pressure tank.Because of the continuous variation in pressure,a transient model of the experiment process is established to calculate the change in flowrate and pressure,the range of Reynolds number as well as the experimental duration under different oil viscosity and various initial pressures.%针对减阻剂室内评价环道存在的问题,设计安装了管径159mm、长300m的室外埋地评价环道,其管径、长度、油品流速更接近于实际管道.该装置采用高压氮气作为动力源,测试段沿线布设高精度压力传感器和高频压力传感器,测试段出口设有超声波流量计,同时安装有耐压罐和常压罐.由于在环道评价试验中装置的压力不断变化,因此建立了试验过程氮气管路、油品管路、氮气罐、耐压罐的瞬态模型,使用VB语言编制了计算程序,用以计算不同粘度和初始压力下的油品流速和压力变化,雷诺数范围和试验时间,判断试验条件的可行性.

  14. Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar

    OpenAIRE

    Aydin-Schmidt, Berit; Morris, Ulrika; Ding, Xavier C; Jovel, Irina; Mwinyi I Msellem; Bergman, Daniel; Islam, Atiqul; Ali, Abdullah S; Polley, Spencer; Gonzalez, Iveth J.; Mårtensson, Andreas; Björkman, Anders

    2017-01-01

    Background New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. Methods HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a commu...

  15. Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar

    OpenAIRE

    Aydin-Schmidt, Berit; Morris, Ulrika; Ding, Xavier C; Jovel, Irina; Msellem, Mwinyi I; Bergman, Daniel; Islam, Atiqul; Ali, Abdullah S.; Polley, Spencer; Gonzalez, Iveth J.; Mårtensson, Andreas; Björkman, Anders

    2017-01-01

    Background New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. Methods HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a commu...

  16. The effects of head-up and head-down tilt on central respiratory chemoreflex loop gain tested by hyperoxic rebreathing.

    Science.gov (United States)

    Skow, Rachel J; Tymko, Michael M; MacKay, Christina M; Steinback, Craig D; Day, Trevor A

    2014-01-01

    Central respiratory chemosensitivity is mediated via chemoreceptor neurons located throughout brain stem tissue. These receptors detect proximal CO2/[H(+)] (i.e., controller gain) and modulate breathing in a classic negative feedback loop. Loop gain (responsiveness) is the theoretical product of controller (chemoreceptors), mixing/feedback (cardiovascular and cerebrovascular systems), and plant (pulmonary system) gains. The level of chemoreceptor stimulation is determined by interactions between mixing and plant gains. The extent to which steady-state changes in body position may affect central chemoreflex loop gain in response to CO2 is unclear. Because of the potential effects of tilt on pulmonary mechanics, we hypothesized that plant gain would be altered by head-up and head-down tilt (HUT, HDT) during hyperoxic rebreathing, which theoretically isolates plant gain by eliminating systemic arterial-tissue gradients. Sixteen subjects (eight females) underwent hyperoxic rebreathing tests on a tilt table to quantify central chemoreflex loop gain in five steady-state positions: 90° HUT, 45° HUT, supine, 45° HDT, and 90° HDT. Respiratory responses (tidal volume, VT; frequency, fR; minute ventilation, VE) were quantified during steady-state and increases in CO2 during rebreathing by linear regression above the ventilatory recruitment threshold (VRT). Using one-factor analysis of variance, we found that there were no differences in the respiratory responses between the five positions (VRT, P=0.711; VT, P=0.290; fR, P=0.748; VE, P=0.325). Our findings suggest that during steady-state orthostatic stress, the ability of subjects to mount a normal ventilatory response to increased CO2 was unaffected, despite any potential changes in pulmonary mechanics associated with positional challenges.

  17. Summary of Test Results From a 1 kW(sub e)-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    Science.gov (United States)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  18. Summary of Test Results From a 1 kWe-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    Science.gov (United States)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  19. Loop-to-loop coupling.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Lucero, Larry Martin; Langston, William L.; Salazar, Robert Austin; Coleman, Phillip Dale; Basilio, Lorena I.; Bacon, Larry Donald

    2012-05-01

    This report estimates inductively-coupled energy to a low-impedance load in a loop-to-loop arrangement. Both analytical models and full-wave numerical simulations are used and the resulting fields, coupled powers and energies are compared. The energies are simply estimated from the coupled powers through approximations to the energy theorem. The transmitter loop is taken to be either a circular geometry or a rectangular-loop (stripline-type) geometry that was used in an experimental setup. Simple magnetic field models are constructed and used to estimate the mutual inductance to the receiving loop, which is taken to be circular with one or several turns. Circuit elements are estimated and used to determine the coupled current and power (an equivalent antenna picture is also given). These results are compared to an electromagnetic simulation of the transmitter geometry. Simple approximate relations are also given to estimate coupled energy from the power. The effect of additional loads in the form of attached leads, forming transmission lines, are considered. The results are summarized in a set of susceptibility-type curves. Finally, we also consider drives to the cables themselves and the resulting common-to-differential mode currents in the load.

  20. Experimental studies and computational benchmark on heavy liquid metal natural circulation in a full height-scale test loop for small modular reactors

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yong-Hoon, E-mail: chaotics@snu.ac.kr [Department of Energy Systems Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826 (Korea, Republic of); Cho, Jaehyun [Korea Atomic Energy Research Institute, 111 Daedeok-daero, 989 Beon-gil, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Lee, Jueun; Ju, Heejae; Sohn, Sungjune; Kim, Yeji; Noh, Hyunyub; Hwang, Il Soon [Department of Energy Systems Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826 (Korea, Republic of)

    2017-05-15

    Highlights: • Experimental studies on natural circulation for lead-bismuth eutectic were conducted. • Adiabatic wall boundaries conditions were established by compensating heat loss. • Computational benchmark with a system thermal-hydraulics code was performed. • Numerical simulation and experiment showed good agreement in mass flow rate. • An empirical relation was formulated for mass flow rate with experimental data. - Abstract: In order to test the enhanced safety of small lead-cooled fast reactors, lead-bismuth eutectic (LBE) natural circulation characteristics have been studied. We present results of experiments with LBE non-isothermal natural circulation in a full-height scale test loop, HELIOS (heavy eutectic liquid metal loop for integral test of operability and safety of PEACER), and the validation of a system thermal-hydraulics code. The experimental studies on LBE were conducted under steady state as a function of core power conditions from 9.8 kW to 33.6 kW. Local surface heaters on the main loop were activated and finely tuned by trial-and-error approach to make adiabatic wall boundary conditions. A thermal-hydraulic system code MARS-LBE was validated by using the well-defined benchmark data. It was found that the predictions were mostly in good agreement with the experimental data in terms of mass flow rate and temperature difference that were both within 7%, respectively. With experiment results, an empirical relation predicting mass flow rate at a non-isothermal, adiabatic condition in HELIOS was derived.

  1. D evelopment and Testing of a Closed Loop Feedback Controlled Magnetorheological Fluid Anti-vibration Mount for Onboard Naval Applications

    Directory of Open Access Journals (Sweden)

    Reji John

    2016-06-01

    Full Text Available An intelligent semi-active anti-vibration mount using a magnetorheological (MR fluid is designed and developed for onboard applications. The mount consists of a load bearing elastomer, MR fluid chamber; MEMS based vibration sensor and a controller for closed loop feedback mechanism. The controller regulates the solenoid current in the MR fluid chamber, which in turn regulates the flow of MR fluid through the valve. Comparison of the performance of MR mount with a passive resilient rubber mount shows that the former provides 7 dB extra damping at resonance compared to the later and the isolation of MR mount starts at 10 Hz compared to 50 Hz by rubber mount. This mount can operate in real time, passive and active modes by using a closed loop feedback control mechanism. The efficacy of the mount for outdoor applications is evaluated by characterizing the mechanical, environmental, electrical and electromagnetic properties as per MIL-17185, JSS-55555 and IEC 61000 standards and found to be superior compared to passive mounts. The mount is being evaluated for onboard applications in INS Ranvijay.

  2. Testing flight software on the ground: Introducing the hardware-in-the-loop simulation method to the Alpha Magnetic Spectrometer on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wenhao, E-mail: wenhao_sun@126.com [Southeast University, Nanjing 210096 (China); Cai, Xudong [Massachusetts Institute of Technology, MA 02139-4307 (United States); Meng, Qiao [Southeast University, Nanjing 210096 (China)

    2016-04-11

    Complex automatic protection functions are being added to the onboard software of the Alpha Magnetic Spectrometer. A hardware-in-the-loop simulation method has been introduced to overcome the difficulties of ground testing that are brought by hardware and environmental limitations. We invented a time-saving approach by reusing the flight data as the data source of the simulation system instead of mathematical models. This is easy to implement and it works efficiently. This paper presents the system framework, implementation details and some application examples.

  3. Simulation of research loop LOBI-MOD2 with RELAP5/MOD3.3 code for LOBI thermo hydraulic test A1-93

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Farshad; Barati, Ramin [Islamic Azad Univ., Shiraz (Iran, Islamic Republic of). Dept. of Electrical Engineering

    2016-06-15

    RELAP5/MOD3.3 is one of the used computer codes for the simulation of event thermal-hydraulics of nuclear power plants. The LOBI test facility is a full-power high-pressure integral system test facility, representing an approximately 1: 700 scale model of a 4-loop, 1300 MWe PWR. A new simulation of the small break LOCA test A1-93 has been carried out in a LOBI/Mod2 facility for reaching good agreement and to evaluate the performance of the RELAP5/MOD3.3 code. Good agreement was obtained in general between the code predictions and the experimental data in transient state.

  4. Relationship between isotopic composition (Δ18O and Δ13C and plaktonic foraminifera test size in core tops from the Brazilian Continental Margin

    Directory of Open Access Journals (Sweden)

    Paula Franco-Fraguas

    2011-12-01

    Full Text Available Stable oxygen (δ18O and carbon (δ13C isotopic signature registered in fossil planktonic foraminifera tests are widely used to reconstruct ancient oceanographic conditions. Test size is a major source of stable isotope variability in planktonic foraminifera found in sediment samples and thus can compromise paleoceanographic interpretations. Test size/stable isotope (δ18O and δ13C relationships were evaluated in two planktonic foraminifer species (Globigerinoides ruber (white and Globorotalia truncatulinoides (right in two core tops from the Brazilian Continental Margin. δ18 Omeasurements were used to predict the depth of calcification of each test size fraction. δ13C offsets for each test size fraction were then estimated. No systematic δ18O changes with size were observed in G. ruber (white suggesting a similar calcification depth range (c.a. 100 m during ontogeny. For G. truncatulinoides (right δ18O values increased with size indicating ontogenetic migration along thermocline waters (250-400 m. δ13C measurements and δ13C offsets increased with size for both species reflecting well known physiological induced ontogenetic-related variability. In G. ruber (white the largest test size fractions (300µm and >355µm more closely reflect δ13C DIC indicating they are best suited for paleoceanographic studies.O tamanho de testa dos foraminíferos é uma importante fonte de variabilidade isotópica (δ18O e δ13C em amostras de sedimento marinho comprometendo as interpretações paloeceanograficas. No presente estudo, avaliou-se a relação entre o sinal isotópico medido em diferentes frações de tamanho de testa das espécies planctônicas, Globigerinoides ruber (branca e Globorotalia truncatulinoides (dextral em amostras de topo de dois testemunhos localizados na Margem Continental Brasileira. Os valores de δ18O foram utilizados para estimar a profundidade de calcificação de cada fração de tamanho. Os desequilíbrios nos valores de

  5. Mitochondrial D-loop {open_quotes}signatures{close_quotes} produced by low-stringency single specific primer PCR constitute a simple comparative human identity test

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, G.; Vago, A.R.; Pena, S.D.J. [and others

    1996-03-01

    We have developed a technique called {open_quotes}LSSP-PCR{close_quotes} (low-stringency single specific primer PCR) that detects single or multiple mutations in DNA. A purified DNA fragment is submitted to PCR by using a single primer specific for one of the extremities of the fragment, under conditions of very low stringency. The primer hybridizes specifically to its complementary extremity and nonspecifically to multiple sites within the fragment, in a sequence-dependent manner. A complex set of reaction products is thus created that, when separated by electrophoresis, constitutes a unique {open_quotes}gene signature.{close_quotes} We here report the application of LSSP-PCR to the detection of sequence variation in the control (D-loop) region of human mtDNA, which is known to differ significantly between unrelated individuals. We prepared human DNA samples from blood and amplified a 1,024-bp portion of the mtDNA control region, using primers L15996 and H408. The amplified mtDNA fragments were then reamplified under LSSP-PCR conditions by using L15996 or H408 as drivers to produce complex signatures that always differed between unrelated individuals and yet were highly reproducible. In contrast, all mother-child pairs tested were identical, as expected from the matrilineal inheritance of mtDNA. Thus, the use of LSSP-PCR to produce D-loop signatures constitutes a powerful new technique for mtDNA-based comparative identity testing. 18 refs., 7 figs.

  6. Power Hardware-in-the-Loop Testing of Multiple Photovoltaic Inverters' Volt-Var Control with Real-Time Grid Model

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sudipta; Nelson, Austin; Hoke, Anderson

    2016-12-12

    Traditional testing methods fall short in evaluating interactions between multiple smart inverters providing advanced grid support functions due to the fact that such interactions largely depend on their placements on the electric distribution systems with impedances between them. Even though significant concerns have been raised by the utilities on the effects of such interactions, little effort has been made to evaluate them. In this paper, power hardware-in-the-loop (PHIL) based testing was utilized to evaluate autonomous volt-var operations of multiple smart photovoltaic (PV) inverters connected to a simple distribution feeder model. The results provided in this paper show that depending on volt-var control (VVC) parameters and grid parameters, interaction between inverters and between the inverter and the grid is possible in some extreme cases with very high VVC slopes, fast response times and large VVC response delays.

  7. Autonomous Aerial Refueling Ground Test Demonstration--A Sensor-in-the-Loop, Non-Tracking Method.

    Science.gov (United States)

    Chen, Chao-I; Koseluk, Robert; Buchanan, Chase; Duerner, Andrew; Jeppesen, Brian; Laux, Hunter

    2015-05-11

    An essential capability for an unmanned aerial vehicle (UAV) to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR). This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC) algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously.

  8. Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

    Directory of Open Access Journals (Sweden)

    Chao-I Chen

    2015-05-01

    Full Text Available An essential capability for an unmanned aerial vehicle (UAV to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR. This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously.

  9. Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar.

    Science.gov (United States)

    Aydin-Schmidt, Berit; Morris, Ulrika; Ding, Xavier C; Jovel, Irina; Msellem, Mwinyi I; Bergman, Daniel; Islam, Atiqul; Ali, Abdullah S; Polley, Spencer; Gonzalez, Iveth J; Mårtensson, Andreas; Björkman, Anders

    2017-01-01

    New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a community-based survey in 2015. The PCR and HTP-LAMP determined malaria prevalences were 1.6% (95%CI 1.3-2.4) and 0.7% (95%CI 0.4-1.1), respectively. The sensitivity of HTP-LAMP compared to PCR was 40.8% (CI95% 27.0-55.8) and the specificity was 99.9% (CI95% 99.8-100). For the PCR positive samples, there was no statistically significant difference between the geometric mean parasite densities among the HTP-LAMP positive (2.5 p/μL, range 0.2-770) and HTP-LAMP negative (1.4 p/μL, range 0.1-7) samples (p = 0.088). Two lab technicians analysed up to 282 samples per day and the HTP-LAMP method was experienced as user friendly. Although field applicable, this high throughput format of LAMP as used here was not sensitive enough to be recommended for detection of asymptomatic low-density infections in areas like Zanzibar, approaching malaria elimination.

  10. Fuskite® preliminary experimental tests based on permeation against vacuum for hydrogen recovery as a potential application in Pb15.7Li loop systems.

    Energy Technology Data Exchange (ETDEWEB)

    Sacristán, R., E-mail: mrosa.sacristan@sener.es [SENER Ingeniería y Sistemas, C/ Provença 392, 5a, 08025 Barcelona (Spain); Veredas, G. [EURATOM-CIEMAT Fusion Assoc., Fusion Technology Division, Av. Complutense 40, 28040 Madrid (Spain); Bonjoch, I. [SENER Ingeniería y Sistemas, C/ Provença 392, 5a, 08025 Barcelona (Spain); Peñalva, I. [UPV/EHU, Departamento de Ingeniería Nuclear y Mecánica de Fluidos, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Calderón, E. [SENER Ingeniería y Sistemas, C/ Provença 392, 5a, 08025 Barcelona (Spain); Alberro, G. [UPV/EHU, Departamento de Ingeniería Nuclear y Mecánica de Fluidos, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Balart, D. [SENER Ingeniería y Sistemas, Avda. Zugazarte 56, 48930 Las Arenas, Vizcaya (Spain); Sarrionandia-Ibarra, A. [UPV/EHU, Departamento de Ingeniería Nuclear y Mecánica de Fluidos, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Pérez, V. [SENER Ingeniería y Sistemas, Avda. Zugazarte 56, 48930 Las Arenas, Vizcaya (Spain); Ibarra, A. [EURATOM-CIEMAT Fusion Assoc., Fusion Technology Division, Av. Complutense 40, 28040 Madrid (Spain); Legarda, F. [UPV/EHU, Departamento de Ingeniería Nuclear y Mecánica de Fluidos, Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2014-10-15

    Highlights: • Full material characterization as far as hydrogen transport properties are concern. • Quantification of permeator leaks and material degasification. • Analysis of H{sub 2} recovered by means of permeation against vacuum in different conditions. • Hydrogen recovery efficiencies determination. - Abstract: Tritium recovery in fusion reactors is one of the main goals in R and D, as a limited inventory is available and its uneconomic production. That is the reason why efficient technologies are indispensable to be developed in order to achieve fast tritium recovery and its subsequent reuse in the system for increasing its self-sufficiency. In this work a flexible tritium recovery demonstrator prototype based on permeation against vacuum concept has been designed and manufactured, as well as all necessary equipment for a Pb15.7Li loop implementation in order to test and demonstrate that an in-pipe integrated solution is possible, and at the same time, to validate the manufacturing process. Thus, efficient rates for more optimized future models could be then extrapolated. The aim of this paper is to show the different testing results that have been carried out in this research project. These results include permeation properties of the material considered for the permeator, as long as it has been manufactured with a novel technique, Selective Laser Melting. They also include vacuum tests on the permeator to quantify possible leakages and to set up and analyze the capability to generate vacuum inside the permeator, and finally, permeation tests with the prototype, in a first stage with a gas mixture of hydrogen and argon inside the loop instead of Pb15.7Li.

  11. NOMAGE4 activities 2011. Part II, Supercritical water loop

    Energy Technology Data Exchange (ETDEWEB)

    Vierstraete, P. (Ecole Nationale Superieure des mines, Paris (France)); Van Nieuwenhove, R. (Institutt for Energiteknikk, OECD Halden Reactor Project (HRP), Kjeller (Norway)); Lauritzen, B. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark))

    2012-01-15

    The supercritical water reactor (SCWR) is one of the six different reactor technologies selected for research and development under the Generation IV program. Several countries have shown interest to this concept but up to now, there exist no in-pile facilities to perform the required material and fuel tests. Working on this direction, the Halden Reactor Project has started an activity in collaboration with Risoe-DTU (with Mr. Rudi Van Nieuwenhove as the project leader) to study the feasibility of a SCW loop in the Halden Reactor, which is a Heavy Boiling Water Reactor (HBWR). The ultimate goal of the project is to design a loop allowing material and fuel test studies at significant mass flow with in-core instrumentation and chemistry control possibilities. The present report focusses on the main heat exchanger required for such a loop in the Halden Reactor. The goal of this heat exchanger is to assure a supercritical flow state inside the test section (the core side) and a subcritical flow state inside the pump section. The objective is to design the heat exchanger in order to optimize the efficiency of the heat transfer and to respect several requirements as the room available inside the reactor hall, the maximal total pressure drop allowed and so on. (Author)

  12. NOMAGE4 activities 2011. Part II, Supercritical water loop

    Energy Technology Data Exchange (ETDEWEB)

    Vierstraete, P. (Ecole Nationale Superieure des mines, Paris (France)); Van Nieuwenhove, R. (Institutt for Energiteknikk, OECD Halden Reactor Project (HRP), Kjeller (Norway)); Lauritzen, B. (Technical Univ. of Denmark, Risoe National Lab. for Sustainable Energy, Roskilde (Denmark))

    2012-01-15

    The supercritical water reactor (SCWR) is one of the six different reactor technologies selected for research and development under the Generation IV program. Several countries have shown interest to this concept but up to now, there exist no in-pile facilities to perform the required material and fuel tests. Working on this direction, the Halden Reactor Project has started an activity in collaboration with Risoe-DTU (with Mr. Rudi Van Nieuwenhove as the project leader) to study the feasibility of a SCW loop in the Halden Reactor, which is a Heavy Boiling Water Reactor (HBWR). The ultimate goal of the project is to design a loop allowing material and fuel test studies at significant mass flow with in-core instrumentation and chemistry control possibilities. The present report focusses on the main heat exchanger required for such a loop in the Halden Reactor. The goal of this heat exchanger is to assure a supercritical flow state inside the test section (the core side) and a subcritical flow state inside the pump section. The objective is to design the heat exchanger in order to optimize the efficiency of the heat transfer and to respect several requirements as the room available inside the reactor hall, the maximal total pressure drop allowed and so on. (Author)

  13. Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar

    Science.gov (United States)

    Morris, Ulrika; Ding, Xavier C.; Jovel, Irina; Msellem, Mwinyi I.; Bergman, Daniel; Islam, Atiqul; Ali, Abdullah S.; Polley, Spencer; Gonzalez, Iveth J.; Mårtensson, Andreas; Björkman, Anders

    2017-01-01

    Background New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. Methods HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a community-based survey in 2015. Results The PCR and HTP-LAMP determined malaria prevalences were 1.6% (95%CI 1.3–2.4) and 0.7% (95%CI 0.4–1.1), respectively. The sensitivity of HTP-LAMP compared to PCR was 40.8% (CI95% 27.0–55.8) and the specificity was 99.9% (CI95% 99.8–100). For the PCR positive samples, there was no statistically significant difference between the geometric mean parasite densities among the HTP-LAMP positive (2.5 p/μL, range 0.2–770) and HTP-LAMP negative (1.4 p/μL, range 0.1–7) samples (p = 0.088). Two lab technicians analysed up to 282 samples per day and the HTP-LAMP method was experienced as user friendly. Conclusions Although field applicable, this high throughput format of LAMP as used here was not sensitive enough to be recommended for detection of asymptomatic low-density infections in areas like Zanzibar, approaching malaria elimination. PMID:28095434

  14. Natively unstructured loops differ from other loops.

    Directory of Open Access Journals (Sweden)

    Avner Schlessinger

    2007-07-01

    Full Text Available Natively unstructured or disordered protein regions may increase the functional complexity of an organism; they are particularly abundant in eukaryotes and often evade structure determination. Many computational methods predict unstructured regions by training on outliers in otherwise well-ordered structures. Here, we introduce an approach that uses a neural network in a very different and novel way. We hypothesize that very long contiguous segments with nonregular secondary structure (NORS regions differ significantly from regular, well-structured loops, and that a method detecting such features could predict natively unstructured regions. Training our new method, NORSnet, on predicted information rather than on experimental data yielded three major advantages: it removed the overlap between testing and training, it systematically covered entire proteomes, and it explicitly focused on one particular aspect of unstructured regions with a simple structural interpretation, namely that they are loops. Our hypothesis was correct: well-structured and unstructured loops differ so substantially that NORSnet succeeded in their distinction. Benchmarks on previously used and new experimental data of unstructured regions revealed that NORSnet performed very well. Although it was not the best single prediction method, NORSnet was sufficiently accurate to flag unstructured regions in proteins that were previously not annotated. In one application, NORSnet revealed previously undetected unstructured regions in putative targets for structural genomics and may thereby contribute to increasing structural coverage of large eukaryotic families. NORSnet found unstructured regions more often in domain boundaries than expected at random. In another application, we estimated that 50%-70% of all worm proteins observed to have more than seven protein-protein interaction partners have unstructured regions. The comparative analysis between NORSnet and DISOPRED2 suggested

  15. Natively unstructured loops differ from other loops.

    Science.gov (United States)

    Schlessinger, Avner; Liu, Jinfeng; Rost, Burkhard

    2007-07-01

    Natively unstructured or disordered protein regions may increase the functional complexity of an organism; they are particularly abundant in eukaryotes and often evade structure determination. Many computational methods predict unstructured regions by training on outliers in otherwise well-ordered structures. Here, we introduce an approach that uses a neural network in a very different and novel way. We hypothesize that very long contiguous segments with nonregular secondary structure (NORS regions) differ significantly from regular, well-structured loops, and that a method detecting such features could predict natively unstructured regions. Training our new method, NORSnet, on predicted information rather than on experimental data yielded three major advantages: it removed the overlap between testing and training, it systematically covered entire proteomes, and it explicitly focused on one particular aspect of unstructured regions with a simple structural interpretation, namely that they are loops. Our hypothesis was correct: well-structured and unstructured loops differ so substantially that NORSnet succeeded in their distinction. Benchmarks on previously used and new experimental data of unstructured regions revealed that NORSnet performed very well. Although it was not the best single prediction method, NORSnet was sufficiently accurate to flag unstructured regions in proteins that were previously not annotated. In one application, NORSnet revealed previously undetected unstructured regions in putative targets for structural genomics and may thereby contribute to increasing structural coverage of large eukaryotic families. NORSnet found unstructured regions more often in domain boundaries than expected at random. In another application, we estimated that 50%-70% of all worm proteins observed to have more than seven protein-protein interaction partners have unstructured regions. The comparative analysis between NORSnet and DISOPRED2 suggested that long

  16. Development and Implementation of a Hardware In-the-Loop Test Bed for Unmanned Aerial Vehicle Control Algorithms

    Science.gov (United States)

    Nyangweso, Emmanuel; Bole, Brian

    2014-01-01

    Successful prediction and management of battery life using prognostic algorithms through ground and flight tests is important for performance evaluation of electrical systems. This paper details the design of test beds suitable for replicating loading profiles that would be encountered in deployed electrical systems. The test bed data will be used to develop and validate prognostic algorithms for predicting battery discharge time and battery failure time. Online battery prognostic algorithms will enable health management strategies. The platform used for algorithm demonstration is the EDGE 540T electric unmanned aerial vehicle (UAV). The fully designed test beds developed and detailed in this paper can be used to conduct battery life tests by controlling current and recording voltage and temperature to develop a model that makes a prediction of end-of-charge and end-of-life of the system based on rapid state of health (SOH) assessment.

  17. Test Results From a Pair of 1-kWe Dual-Opposed Free-Piston Stirling Power Convertors Integrated With a Pumped NaK Loop

    Science.gov (United States)

    Geng, Steven M.; Briggs, Maxwell H.; Penswick, L. Barry; Pearson, J. Boise; Godfroy, Thomas J.

    2011-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1-kW-class free-piston Stirling convertors were modified to operate with a NaK (sodium (Na) and potassium (K)) liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The convertors were successfully tested at the Marshall Space Flight Center (MSFC) from June 6 through July 14, 2009. The convertors were operated for a total test time of 66 hr and 16 min. The tests included (a) performance mapping the convertors over various hot- and cold-end temperatures, piston amplitudes, and NaK flow rates and (b) transient test conditions to simulate various startup (i.e., low-, medium-, and high-temperature startups) and fault scenarios (i.e., loss of heat source, loss of NaK pump, convertor stall, etc.). This report documents the results of this testing

  18. Stem loop-mediated isothermal amplification test: comparative analysis with classical LAMP and PCR in detection of Entamoeba histolytica in Kenya.

    Science.gov (United States)

    Mwendwa, Fridah; Mbae, Cecilia K; Kinyua, Johnson; Mulinge, Erastus; Mburugu, Gitonga Nkanata; Njiru, Zablon K

    2017-03-31

    Entamoeba histolytica, the causative agent for amoebiasis is a considerable burden to population in the developing countries where it accounts for over 50 million infections. The tools for detection of amoebiasis are inadequate and diagnosis relies on microscopy which means a significant percent of cases remain undiagnosed. Moreover, tests formats that can be rapidly applied in rural endemic areas are not available. In this study, a loop-mediated isothermal test (LAMP) based on 18S small subunit ribosomal RNA gene was designed with extra reaction accelerating primers (stem primers) and compared with the published LAMP and PCR tests in detection of E. histolytica DNA in clinical samples. The stem LAMP test indicated shorter time to results by an average 11 min and analytical sensitivity of 10(-7) (~30 pg/ml) compared to the standard LAMP and PCR which showed sensitivities levels of 10(-5) (~3 ng/ml) and 10(-4) (~30 ng/ml) respectively using tenfold serial dilution of DNA. In the analysis of clinical specimens positive for Entamoeba spp. trophozoites and cysts using microscopy, the stem LAMP test detected E. histolytica DNA in 36/126, standard LAMP test 20/126 and PCR 17/126 cases respectively. There was 100% agreement in detection of the stem LAMP test product using fluorescence of SYTO-9 dye in real time machine, through addition of 1/10 dilution of SYBR(®) Green I and electrophoresis in 2% agarose gel stained with ethidium bromide. The stem LAMP test developed in this study indicates potential towards detection of E. histolytica.

  19. Follow-up strategies after treatment (large loop excision of the transformation zone (LLETZ)) for cervical intraepithelial neoplasia (CIN): Impact of human papillomavirus (HPV) test.

    Science.gov (United States)

    van der Heijden, Esther; Lopes, Alberto D; Bryant, Andrew; Bekkers, Ruud; Galaal, Khadra

    2015-01-06

    Development of cancer of the cervix is a multi-step process as before cervical cancer develops, cervical cells undergo changes and become abnormal. These abnormalities are called cervical intraepithelial neoplasia (CIN) and are associated with increased risk of subsequent invasive cancer of the cervix. Oncogenic high-risk human papillomavirus (hrHPV), the causative agent of cervical cancer and its precursor lesions, is present in up to one-third of women following large loop excision of the transformation zone (LLETZ) treatment and is associated with increased risk of residual disease and disease recurrence. HPV testing may serve as a surveillance tool for identifying women at higher risk of recurrence. High-risk human papillomavirus testing will enable us to identify women at increased risk of residual or recurrent CIN and therefore will allow us to offer closer surveillance and early treatment, when indicated. • To evaluate the effectiveness and safety of hrHPV testing after large loop excision of the transformation zone (LLETZ) treatment• To determine optimal follow-up management strategies following LLETZ treatment according to hrHPV status We searched the Cochrane Gynacological Cancer Review Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed and PsycINFO up to August 2013. We searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies, and we contacted experts in the field. We searched for randomised control trials (RCTs) that compared follow-up management strategies following LLETZ treatment for CIN. Two review authors independently assessed whether potentially relevant studies met the inclusion criteria. No trials were found; therefore no data were analysed. The search identified 813 references on MEDLINE, 418 on EMBASE, 22 on CINAHL, 666 on PubMed, 291 on PsycINFO and

  20. Application of a Virtual Reactivity Feedback Control Loop in Non-Nuclear Testing of a Fast Spectrum Reactor

    Science.gov (United States)

    Bragg-Sitton, Shannon M.; Forsbacka, Matthew

    2004-01-01

    For a compact, fast-spectrum reactor, reactivity feedback is dominated by core deformation at elevated temperature. Given the use of accurate deformation measurement techniques, it is possible to simulate nuclear feedback in non-nuclear electrically heated reactor tests. Implementation of simulated reactivity feedback in response to measured deflection is being tested at the NASA Marshall Space Flight Center Early Flight Fission Test Facility (EFF-TF). During tests of the SAFE-100 reactor prototype, core deflection was monitored using a high resolution camera. "virtual" reactivity feedback was accomplished by applying the results of Monte Carlo calculations (MCNPX) to core deflection measurements; the computational analysis was used to establish the reactivity worth of van'ous core deformations. The power delivered to the SAFE-100 prototype was then dusted accordingly via kinetics calculations, The work presented in this paper will demonstrate virtual reactivity feedback as core power was increased from 1 kilowatt(sub t), to 10 kilowatts(sub t), held approximately constant at 10 kilowatts (sub t), and then allowed to decrease based on the negative thermal reactivity coefficient.

  1. Exceptional F(4) Higher-Spin Theory in AdS(6) at One-Loop and other Tests of Duality

    CERN Document Server

    Gunaydin, Murat; Tran, Tung

    2016-01-01

    We study the higher-spin gauge theory in six-dimensional anti-de Sitter space $AdS_6$ that is based on the exceptional Lie superalgebra $F(4)$. The relevant higher-spin algebra was constructed in arXiv:1409.2185 [hep-th]. We determine the spectrum of the theory and show that it contains the physical fields of the Romans $F(4)$ gauged supergravity. The full spectrum consists of an infinite tower of unitary supermultiplets of $F(4)$ which extend the Romans multiplet to higher spins plus a single short supermultiplet. Motivated by applications to this novel supersymmetric higher-spin theory as well as to other theories, we extend the known one-loop tests of $AdS/CFT$ duality in various directions. The spectral zeta-function is derived for the most general case of fermionic and mixed-symmetry fields, which allows one to test the Type-A and B theories and supersymmetric extensions thereof in any dimension. We also study higher-spin doubletons and partially-massless fields. While most of the tests are successfully ...

  2. Exceptional F(4) higher-spin theory in AdS{sub 6} at one-loop and other tests of duality

    Energy Technology Data Exchange (ETDEWEB)

    Günaydin, Murat [Institute for Gravitation and the Cosmos Physics Department, Pennsylvania State University, University Park, PA 16802 (United States); Skvortsov, Evgeny [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians University Munich, Theresienstr. 37, D-80333 Munich (Germany); Lebedev Institute of Physics, Leninsky ave. 53, 119991 Moscow (Russian Federation); Tran, Tung [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)

    2016-11-28

    We study the higher-spin gauge theory in six-dimensional anti-de Sitter space AdS{sub 6} that is based on the exceptional Lie superalgebra F(4). The relevant higher-spin algebra was constructed in http://arxiv.org/abs/1409.2185. We determine the spectrum of the theory and show that it contains the physical fields of the Romans F(4) gauged supergravity. The full spectrum consists of an infinite tower of unitary supermultiplets of F(4) which extend the Romans multiplet to higher spins plus a single short supermultiplet. Motivated by applications to this novel supersymmetric higher-spin theory as well as to other theories, we extend the known one-loop tests of AdS/CFT duality in various directions. The spectral zeta-function is derived for the most general case of fermionic and mixed-symmetry fields, which allows one to test the Type-A and B theories and supersymmetric extensions thereof in any dimension. We also study higher-spin doubletons and partially-massless fields. While most of the tests are successfully passed, the Type-B theory in all even dimensional anti-de Sitter spacetimes presents an interesting puzzle: the free energy as computed from the bulk is not equal to that of the free fermion on the CFT side, though there is some systematics to the discrepancy.

  3. Network defense simulation test model based on hardware-in-the-loop%基于半实物的网络防御仿真测试模型

    Institute of Scientific and Technical Information of China (English)

    毕治国; 张明清; 唐俊; 孔红山

    2011-01-01

    Aiming at the deficiency of high cost and risk in testing network defense in real network, Hardware-in-the-loop simulation is introduced in network defense testing research, and a defense testing model is erected based on HITLS through analyzing of the elements of HITLS, and then two basic applications of model are given. The implementation technology of this model, and a method used to extend attacking simulation based on hardware-in-the-loop support are analyzed in detail by OPNET through creating custom packet-translation functions. At last, a HITLS experiment is given to prove the validity of this model. This model can make real attacking and defending behaviors run in simulation network, which maps the real node into the simulation network. The model can not only avoid building complex hardware experiment platform but also make the process of testing in security and control, even more it can improve the reliability of simulation.%针对在真实网络中对防御进行测试存在高成本高风险的不足,将半实物网络仿真方法引入防御测试研究中,分析了半实物网络仿真的原理,建立了一种基于半实物的网络防御仿真测试模型,给出了模型的两种基本应用.着重对网络防御半实物仿真测试的实现技术进行了分析,通过自定义包转换的方法来扩展OPNET所能支持的攻击的半实物仿真,最后通过仿真实验来验证了模型的有效性.该模型能够将实际节点映射到虚拟网络中,使防御测试中的实际攻防行为在虚拟网络中运行,从而既避免了建立复杂的真实测试平台,又使得测试过程安全可控,还提高了仿真测试结果的可信度.

  4. Testing the AdS/CFT correspondence by Monte Carlo calculation of BPS and non-BPS Wilson loops in 4d N=4 super-Yang-Mills theory

    CERN Document Server

    Honda, Masazumi; Nishimura, Jun; Tsuchiya, Asato

    2011-01-01

    We test the AdS/CFT correspondence by calculating Wilson loops in N = 4 super Yang-Mills theory on R*S^3 in the planar limit. Our method is based on a novel large-N reduction, which reduces the problem to Monte Carlo calculations in the plane-wave matrix model or the BMN matrix model, which is a 1d gauge theory with 16 supercharges. By using the gauge-fixed momentumspace simulation, we obtain results respecting 16 supersymmetries. We report on the Monte Carlo results for the BPS circular Wilson loop, which reproduce the exact result up to strong coupling. As a future prospect, we calculate a track-shapedWilson loop from the gravity side, which shows that a clear test of the AdS/CFT for the non-BPS case is also feasible.

  5. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  6. Loop-Mediated Isothermal Amplification Test for Trypanosoma gambiense Group 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness

    Science.gov (United States)

    Mburugu, Gitonga N.

    2017-01-01

    The World Health Organization has targeted Human African Trypanosomiasis (HAT) for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring) since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers) to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min), were 10–100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.

  7. Loop-Mediated Isothermal Amplification Test for Trypanosoma gambiense Group 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness

    Directory of Open Access Journals (Sweden)

    Zablon K. Njiru

    2017-01-01

    Full Text Available The World Health Organization has targeted Human African Trypanosomiasis (HAT for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min, were 10–100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.

  8. Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, R.W.; MacPherson, R.E.

    1983-03-01

    The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

  9. Comparison of three small-break loss-of-coolant accident tests with different break locations using the system-integrated modular advanced reactor-integral test loop facility to estimate the safety of the smart design

    Directory of Open Access Journals (Sweden)

    Hwang Bae

    2017-08-01

    Full Text Available Three small-break loss-of-coolant accident (SBLOCA tests with safety injection pumps were carried out using the integral-effect test loop for SMART (System-integrated Modular Advanced ReacTor, i.e., the SMART-ITL facility. The types of break are a safety injection system line break, shutdown cooling system line break, and pressurizer safety valve line break. The thermal–hydraulic phenomena show a traditional behavior to decrease the temperature and pressure whereas the local phenomena are slightly different during the early stage of the transient after a break simulation. A safety injection using a high-pressure pump effectively cools down and recovers the inventory of a reactor coolant system. The global trends show reproducible results for an SBLOCA scenario with three different break locations. It was confirmed that the safety injection system is robustly safe enough to protect from a core uncovery.

  10. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  11. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  12. 核电厂DCS闭环测试平台的开发及应用%Development and Application of Nuclear Power Plant DCS Closed-Loop Test Platform

    Institute of Scientific and Technical Information of China (English)

    侯东; 林萌; 杨宗伟; 刘鹏飞; 杨燕华

    2011-01-01

    开发了可用于核电厂数字化控制系统( DCS)闭环测试的测试平台,该平台具有较高的灵活性和可扩展性.建立了岭澳核电站二期系统模型,通过汽轮机10%FP(满功率)阶跃降负荷瞬态下的稳压器压力和液位控制系统测试,演示应用该平台进行DCS闭环测试和发现并查找问题的方法.该测试平台在岭澳核电站二期DCS闭环测试中得到了成功应用.%A simulation platform with high flexibility and extensibility for nuclear power plant DCS closed-loop test has been developed. The system modeling for Ling'ao Phase II nuclear power plant has been built. Through an example of pressurizer pressure and water level control system testing under the condition of a 10%FP turbine power step-down,the way of using the platform for closed-loop DCS test and how to locate DCS problems were demonstrated. This test platform has been applied to DCS closed-loop test in Ling'ao Phase II successfully.

  13. The finite Bruck Loops

    CERN Document Server

    Baumeister, Barbara

    2009-01-01

    We continue the work by Aschbacher, Kinyon and Phillips [AKP] as well as of Glauberman [Glaub1,2] by describing the structure of the finite Bruck loops. We show essentially that a finite Bruck loop $X$ is the direct product of a Bruck loop of odd order with either a soluble Bruck loop of 2-power order or a product of loops related to the groups $PSL_2(q)$, $q= 9$ or $q \\geq 5$ a Fermat prime. The latter possibillity does occur as is shown in [Nag1, BS]. As corollaries we obtain versions of Sylow's, Lagrange's and Hall's Theorems for loops.

  14. Análise das forças produzidas por alças de nivelamento: ensaio mecânico Analysis of the forces produced by loops: mechanical testing

    Directory of Open Access Journals (Sweden)

    Milton Santamaria Jr.

    2006-02-01

    Full Text Available OBJETIVO: avaliar a força aplicada pelas alças simples, L divergente e L convergente, confeccionadas no fio de 0,016 polegadas, durante a fase de nivelamento, em função da deformação produzida e da amarração do ômega na extremidade posterior dos arcos. METODOLOGIA: empregou-se um modelo especialmente construído para o experimento, mensurando-se as forças por meio da máquina universal EMIC-DL10.000. RESULTADOS E CONCLUSÕES: a deformação produzida variou de 0,5 a 2mm e gerou força que variou de 75,1 a 268,5gf para alça simples, 69,7 a 241,0gf para a alça L divergente e 67,0 a 220,4gf para a alça L convergente, na condição de não se amarrar o ômega. Quando o ômega foi amarrado ao molar, a força variou de 105,0 a 311,6gf; 70,8 a 251,4gf e 69,4 a 243,4gf; respectivamente. Aplicou-se teste t de Student para variáveis pareadas e foi verificado que a alça simples produziu maior força de acordo com a deformação, seguida da alça L divergente e L convergente (pAIM: the aim of this work was to assess the force applied by the vertical loop, divergent boot loop and convergent boot loop, made with 0.016" arch wire, during the leveling phase in function of the produced deformation and of the tie back in the posterior extremity of the arch wire. METHODS: a special experimental model was built for this study, and a Universal Test Machine EMIC-DL10.000 was used to evaluate force levels. RESULTS AND CONCLUSIONS: The produced deformation varied of 0.5 to 2mm and the force produced varied from 75.1 to 268.5gf for vertical loop, 69.7 to 241.0gf for the divergent boot loop and 67.0 to 220.4gf for the convergent boot loop, in the condition of not tying back the wire. When wire was tied back the force varied from 105.0 to 311.6gf; 70.8 to 251.4gf and 69.4 to 243.4gf; respectively. It was applied Student t test and it was verified that the vertical loop produces larger force in agreement with the deformation followed by the divergent boot

  15. Efficient Loop Navigation for Symbolic Execution

    CERN Document Server

    Obdrzalek, Jan

    2011-01-01

    Symbolic execution is a successful and very popular technique used in software verification and testing. A key limitation of symbolic execution is in dealing with code containing loops. The problem is that even a single loop can generate a huge number of different symbolic execution paths, corresponding to different number of loop iterations and taking various paths through the loop. We introduce a technique which, given a start location above some loops and a target location anywhere below these loops, returns a feasible path between these two locations, if such a path exists. The technique infers a collection of constraint systems from the program and uses them to steer the symbolic execution towards the target. On reaching a loop it iteratively solves the appropriate constraint system to find out which path through this loop to take, or, alternatively, whether to continue below the loop. To construct the constraint systems we express the values of variables modified in a loop as functions of the number of ...

  16. 智能变电站网络闭环测试系统实现与应用%Realization and Application of Close-loop Testing System of Smart Substation Network

    Institute of Scientific and Technical Information of China (English)

    谈树峰; 冯善强; 王红星

    2015-01-01

    On the basis of introduction on research status quo of smart substation network,this paper analyzes key technolo-gies for testing on smart substation network. Combining specific application and traditional network testing of smart substa-tion,it introduces design and development of close-loop testing system of the smart substation network which has functions of real-time analysis on network messages. By comparing with existing testing methods,it points out technical advantages of the close-loop testing system. By means of monomer testing,system-level testing and network switch testing in some 220 kV smart substation,it verifies effectiveness of this close-loop testing system.%在介绍智能变电站网络研究现状的基础上,分析了智能变电站网络测试的关键技术。结合智能变电站的具体应用与传统的网络测试,设计开发了具备网络报文实时分析功能的智能变电站网络闭环测试系统。通过比对现有的测试手段,指出了闭环测试系统的技术优势。通过对某220 kV 智能变电站工厂验收的单体测试、系统级测试和网络交换机测试,验证了闭环测试系统的有效性。

  17. Design and test of a closed-loop FES system for supporting function of the hemiparetic hand based on automatic detection using the Microsoft Kinect sensor

    DEFF Research Database (Denmark)

    Simonsen, Daniel; Spaich, Erika G.; Hansen, John

    2017-01-01

    This paper describes the design of a FES system automatically controlled in a closed loop using a Microsoft Kinect sensor, for assisting both cylindrical grasping and hand opening. The feasibility of the system was evaluated in real-time in stroke patients with hand function deficits. A hand...

  18. Loop quantum gravity and observations

    CERN Document Server

    Barrau, A

    2014-01-01

    Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We review here some possible ways to observe loop quantum gravity effects either in the framework of cosmology or in astroparticle physics.

  19. Pseudonoise code tracking loop

    Science.gov (United States)

    Laflame, D. T. (Inventor)

    1980-01-01

    A delay-locked loop is presented for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.

  20. All digital pulsewidth control loop

    Science.gov (United States)

    Huang, Hong-Yi; Jan, Shiun-Dian; Pu, Ruei-Iun

    2013-03-01

    This work presents an all-digital pulsewidth control loop (ADPWCL). The proposed system accepts a wide range of input duty cycles and performs a fast correction to the target output pulsewidth. An all-digital delay-locked loop (DLL) with fast locking time using a simplified time to digital converter and a new differential two-step delay element is proposed. The area of the delay element is much smaller than that in conventional designs, while having the same delay range. A test chip is verified in a 0.18-µm CMOS process. The measured duty cycle ranges from 4% to 98% with 7-bit resolution.

  1. LISA Pathfinder: OPD loop characterisation

    Science.gov (United States)

    Born, Michael; LPF Collaboration

    2017-05-01

    The optical metrology system (OMS) of the LISA Pathfinder mission is measuring the distance between two free-floating test masses with unprecedented precision. One of the four OMS heterodyne interferometers reads out the phase difference between the reference and the measurement laser beam. This phase from the reference interferometer is common to all other longitudinal interferometer read outs and therefore subtracted. In addition, the phase is fed back via the digital optical pathlength difference (OPD) control loop to keep it close to zero. Here, we analyse the loop parameters and compare them to on-ground measurement results.

  2. Supersymmetric Wilson loops at two loops

    CERN Document Server

    Bassetto, Antonio; Pucci, Fabrizio; Seminara, Domenico

    2008-01-01

    We study the quantum properties of certain BPS Wilson loops in ${\\cal N}=4$ supersymmetric Yang-Mills theory. They belong to a general family, introduced recently, in which the addition of particular scalar couplings endows generic loops on $S^3$ with a fraction of supersymmetry. When restricted to $S^2$, their quantum average has been further conjectured to be exactly computed by the matrix model governing the zero-instanton sector of YM$_2$ on the sphere. We perform a complete two-loop analysis on a class of cusped Wilson loops lying on a two-dimensional sphere, finding perfect agreement with the conjecture. The perturbative computation reproduces the matrix-model expectation through a highly non-trivial interplay between ladder diagrams and self-energies/vertex contributions, suggesting the existence of a localization procedure.

  3. The Statistical Loop Analyzer (SLA)

    Science.gov (United States)

    Lindsey, W. C.

    1985-01-01

    The statistical loop analyzer (SLA) is designed to automatically measure the acquisition, tracking and frequency stability performance characteristics of symbol synchronizers, code synchronizers, carrier tracking loops, and coherent transponders. Automated phase lock and system level tests can also be made using the SLA. Standard baseband, carrier and spread spectrum modulation techniques can be accomodated. Through the SLA's phase error jitter and cycle slip measurements the acquisition and tracking thresholds of the unit under test are determined; any false phase and frequency lock events are statistically analyzed and reported in the SLA output in probabilistic terms. Automated signal drop out tests can be performed in order to trouble shoot algorithms and evaluate the reacquisition statistics of the unit under test. Cycle slip rates and cycle slip probabilities can be measured using the SLA. These measurements, combined with bit error probability measurements, are all that are needed to fully characterize the acquisition and tracking performance of a digital communication system.

  4. Dynamic PID loop control

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.; /Fermilab

    2011-06-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  5. Dynamic PID loop control

    CERN Document Server

    Pei, L; Theilacker, J; Soyars, W; Martinez, A; Bossert, R; DeGraff, B; Darve, C

    2012-01-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters' oscillation.

  6. Vortex loops and Majoranas

    Energy Technology Data Exchange (ETDEWEB)

    Chesi, Stefano [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); CEMS, RIKEN, Wako, Saitama 351-0198 (Japan); Jaffe, Arthur [Harvard University, Cambridge, Massachusetts 02138 (United States); Department of Physics, University of Basel, Basel (Switzerland); Institute for Theoretical Physics, ETH Zürich, Zürich (Switzerland); Loss, Daniel [CEMS, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Physics, University of Basel, Basel (Switzerland); Pedrocchi, Fabio L. [Department of Physics, University of Basel, Basel (Switzerland)

    2013-11-15

    We investigate the role that vortex loops play in characterizing eigenstates of interacting Majoranas. We give some general results and then focus on ladder Hamiltonian examples as a test of further ideas. Two methods yield exact results: (i) A mapping of certain spin Hamiltonians to quartic interactions of Majoranas shows that the spectra of these two examples coincide. (ii) In cases with reflection-symmetric Hamiltonians, we use reflection positivity for Majoranas to characterize vortices in the ground states. Two additional methods suggest wider applicability of these results: (iii) Numerical evidence suggests similar behavior for certain systems without reflection symmetry. (iv) A perturbative analysis also suggests similar behavior without the assumption of reflection symmetry.

  7. ECV - 'Electronically Controlled Vehicle'- A universal drive for open loop tests; ECV - 'Electronically Controlled Vehicle': eine universelle Fahrmaschine zur Durchfuehrung von Open Loop Versuchskonfigurationen

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M.; Sokoliuk, A. [TUeV Automotive GmbH, Muenchen (Germany)

    2001-07-01

    As a rule, the driver is the weakest link in the test set-up. In order to make dynamic driving tests more easily reproducible, the electronically controlled vehicle is recommended, which is used by TUeV Automotive for crash tests since about 10 years ago. [German] Das schwaechste Glied in der Kette einer Messung im Fahrversuch ist in der Regel der Versuchsfahrer. Um eine bessere Reproduzierbarkeit von fahrdynamischen Versuchen zu gewaehrleisten, bietet sich der Einsatz des ECV-Systems (Electronically Controlled Vehicle) als universelle Fahrmaschine an. Diese Technologie wird bei der TUeV Automotive bereits seit 10 Jahren bei Crashversuchen mit selbstfahrenden Fahrzeugen angewandt. (orig.)

  8. Multiple Flow Loop SCADA System Implemented on the Production Prototype Loop

    Energy Technology Data Exchange (ETDEWEB)

    Baily, Scott A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalmas, Dale Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wheat, Robert Mitchell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-16

    The following report covers FY 15 activities to develop supervisory control and data acquisition (SCADA) system for the Northstar Moly99 production prototype gas flow loop. The goal of this effort is to expand the existing system to include a second flow loop with a larger production-sized blower. Besides testing the larger blower, this system will demonstrate the scalability of our solution to multiple flow loops.

  9. Tensile and Fatigue Testing and Material Hardening Model Development for 508 LAS Base Metal and 316 SS Similar Metal Weld under In-air and PWR Primary Loop Water Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish [Argonne National Lab. (ANL), Argonne, IL (United States); Soppet, William [Argonne National Lab. (ANL), Argonne, IL (United States); Majumdar, Saurin [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, Ken [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable in September 2015 under the work package for environmentally assisted fatigue under DOE’s Light Water Reactor Sustainability program. In an April 2015 report we presented a baseline mechanistic finite element model of a two-loop pressurized water reactor (PWR) for systemlevel heat transfer analysis and subsequent thermal-mechanical stress analysis and fatigue life estimation under reactor thermal-mechanical cycles. In the present report, we provide tensile and fatigue test data for 508 low-alloy steel (LAS) base metal, 508 LAS heat-affected zone metal in 508 LAS–316 stainless steel (SS) dissimilar metal welds, and 316 SS-316 SS similar metal welds. The test was conducted under different conditions such as in air at room temperature, in air at 300 oC, and under PWR primary loop water conditions. Data are provided on materials properties related to time-independent tensile tests and time-dependent cyclic tests, such as elastic modulus, elastic and offset strain yield limit stress, and linear and nonlinear kinematic hardening model parameters. The overall objective of this report is to provide guidance to estimate tensile/fatigue hardening parameters from test data. Also, the material models and parameters reported here can directly be used in commercially available finite element codes for fatigue and ratcheting evaluation of reactor components under in-air and PWR water conditions.

  10. Cosmic string loop shapes

    CERN Document Server

    Blanco-Pillado, Jose J; Shlaer, Benjamin

    2015-01-01

    We analyze the shapes of cosmic string loops found in large-scale simulations of an expanding-universe string network. The simulation does not include gravitational back reaction, but we model that process by smoothing the loop using Lorentzian convolution. We find that loops at formation consist of generally straight segments separated by kinks. We do not see cusps or any cusp-like structure at the scale of the entire loop, although we do see very small regions of string that move with large Lorentz boosts. However, smoothing of the string almost always introduces two cusps on each loop. The smoothing process does not lead to any significant fragmentation of loops that were in non-self-intersecting trajectories before smoothing.

  11. Coxeter-Chein Loops

    CERN Document Server

    Blok, Rieuwert J

    2011-01-01

    In 1974 Orin Chein discovered a new family of Moufang loops which are now called Chein loops. Such a loop can be created from any group $W$ together with $\\mathbb{Z}_2$ by a variation on a semi-direct product. We study these loops in the case where $W$ is a Coxeter group and show that it has what we call a Chein-Coxeter system, a small set of generators of order 2, together with a set of relations closely related to the Coxeter relations and Chein relations. As a result we are able to give amalgam presentations for Coxeter-Chein loops. This is to our knowledge the first such presentation for a Moufang loop.

  12. Simple system for locating ground loops.

    Science.gov (United States)

    Bellan, P M

    2007-06-01

    A simple low-cost system for rapid identification of the cables causing ground loops in complex instrumentation configurations is described. The system consists of an exciter module that generates a 100 kHz ground loop current and a detector module that determines which cable conducts this test current. Both the exciter and detector are magnetically coupled to the ground circuit so there is no physical contact to the instrumentation system under test.

  13. Coxeter-Chein Loops

    OpenAIRE

    Blok, Rieuwert J.; Gagola III, Stephen

    2011-01-01

    In 1974 Orin Chein discovered a new family of Moufang loops which are now called Chein loops. Such a loop can be created from any group $W$ together with $\\mathbb{Z}_2$ by a variation on a semi-direct product. We study these loops in the case where $W$ is a Coxeter group and show that it has what we call a Chein-Coxeter system, a small set of generators of order 2, together with a set of relations closely related to the Coxeter relations and Chein relations. As a result we are able to give am...

  14. Observational Evidence for Loop-Loop Interaction

    Science.gov (United States)

    Guiping, W.; Guangli, H.; Yuhua, T.; Aoao, X.

    2004-01-01

    Through analysis of the data including the hard x-ray(BASTE) microwave(NoRP) and magnetogram(MDI from SOHO) as well as the images of soft x-ray(YHKOH) and EIT(SOHO) on Apr. 151998 solar flare in the active region 8203(N30W12) we found: (1) there are similar quasi period oscillation in the profile of hard x-ray flux (25-5050-100keV) and microwave flux(1GHz) with duration of 85+/-25s every peak includes two sub-peak structures; (2) in the preheat phase of the flare active magnetic field changes apparently and a s-pole spot emerges ; (3) several EIT and soft x-ray loops exist and turn into bright . All of these may suggest that loop-loop interaction indeed exist. Through reconnection the electrons may be accelerated and the hard x-ray and microwave emission take place.

  15. On the Properties of Cosmic String Loops

    Science.gov (United States)

    Casper, Paul Henry

    1996-01-01

    When coupled with the prevailing ideas of cosmology, the standard model of particle physics implies that the early universe underwent a sequence of phase transitions. Such phase transitions can lead to topological defects such as magnetic monopoles, domain walls and cosmic strings. The formation and subsequent evolution of a network of cosmic strings may have played a key role in the development of the early universe. One of the most crucial elements in the evolution of the cosmic string network is the formation and decay of closed loops of cosmic string. After formation, the loops lose their energy by emitting gravitational radiation. This provides the primary energy loss mechanism for the cosmic string network. In addition, the cosmic string loops may display a number of observable features through which the cosmic string model may be constrained. In this dissertation a number of the key properties of cosmic string loops are investigated. A general method for determining the rates at which cosmic string loops radiate both energy and linear momentum is developed and implemented. Exact solutions for the radiation rates of a several new classes of loops are derived and used to test the validity of using the piecewise linear method on smooth loop trajectories. A large set of representative loop trajectories is produced using the method of loop fragmentation. These trajectories are analyzed to provide useful information on the properties of realistic cosmic string loops. The fraction of cosmic string loops which would collapse to form black holes is determined and used to place a new observational limit on the mass per unit length of cosmic strings.

  16. A one-loop test for construction of 4D N=4 SYM from 2D SYM via fuzzy sphere geometry

    CERN Document Server

    Matsuura, So

    2015-01-01

    As a perturbative check of the construction of four-dimensional (4D) ${\\cal N}=4$ supersymmetric Yang-Mills theory (SYM) from mass deformed ${\\cal N}=(8,8)$ SYM on the two-dimensional (2D) lattice, the one-loop effective action for scalar kinetic terms is computed in ${\\cal N}=4$ $U(k)$ SYM on ${\\mathbb R}^2 \\times$ (fuzzy $S^2$), which is obtained by expanding 2D ${\\cal N}=(8,8)$ $U(N)$ SYM with mass deformation around its fuzzy sphere classical solution. The radius of the fuzzy sphere is proportional to the inverse of the mass. We consider the two successive limits; (1) decompactify the fuzzy sphere to a noncommutative (Moyal) plane and (2) turn off the noncommutativity of the Moyal plane. It is clear at the classical level to obtain the ordinary ${\\cal N}=4$ SYM on ${\\mathbb R}^4$ in the limits, while it is nontrivial at the quantum level. The one-loop effective action for $SU(k)$ sector of the gauge group $U(k)$ coincides with that of the ordinary 4D ${\\cal N}=4$ SYM in the above limits. Although "noncomm...

  17. Design and Test of a Closed-Loop FES System for Supporting Function of the Hemiparetic Hand Based on Automatic Detection using the Microsoft Kinect sensor.

    Science.gov (United States)

    Simonsen, Daniel; Spaich, Erika G; Hansen, John; Andersen, Ole K

    2016-10-26

    This paper describes the design of a FES system automatically controlled in a closed loop using a Microsoft Kinect sensor, for assisting both cylindrical grasping and hand opening. The feasibility of the system was evaluated in real-time in stroke patients with hand function deficits. A hand function exercise was designed in which the subjects performed an arm and hand exercise in sitting position. The subject had to grasp one of two differently sized cylindrical objects and move it forward or backwards in the sagittal plane. This exercise was performed with each cylinder with and without FES support. Results showed that the stroke patients were able to perform up to 29% more successful grasps when they were assisted by FES. Moreover, the hand grasp-and-hold and hold-and-release durations were shorter for the smaller of the two cylinders. FES was appropriately timed in more than 95% of all trials indicating successful closed loop FES control. Future studies should incorporate options for assisting forward reaching in order to target a larger group of stroke patients.

  18. Capillary fluid loop developments in Astrium

    Energy Technology Data Exchange (ETDEWEB)

    Figus, C.; Ounougha, L.; Bonzom, P. [Astrium SAS, Toulouse (France); Supper, W. [ESA/ESTEC, Noordwijk (Netherlands); Puillet, C. [CNES, Toulouse (France)

    2003-06-01

    Over the past decade, Astrium has been involved in the development of capillary pumped fluid loops. In the frame of the French technological demonstrator spacecraft called STENTOR, Astrium has gained experience on capillary fluid loop design and manufacturing. After the STENTOR cylindrical evaporator type was successfully tested and qualified, Astrium has developed miniaturised fluid loops for thermal dissipation of electronic devices. For such applications, the use of a flat shape evaporator is very promising, limiting the volume and the mass of the thermal hardware. Both technologies have been submitted to a comprehensive one-g test program and will be flight-tested in the near future. Through a comparative of the reached performances, some main advantages and drawbacks of each design are listed and a definition of what should be the next generation of Astrium fluid loops is given. (author)

  19. Loops In Proteins (LIP)--a comprehensive loop database for homology modelling.

    Science.gov (United States)

    Michalsky, E; Goede, A; Preissner, R

    2003-12-01

    One of the most important and challenging tasks in protein modelling is the prediction of loops, as can be seen in the large variety of existing approaches. Loops In Proteins (LIP) is a database that includes all protein segments of a length up to 15 residues contained in the Protein Data Bank (PDB). In this study, the applicability of LIP to loop prediction in the framework of homology modelling is investigated. Searching the database for loop candidates takes less than 1 s on a desktop PC, and ranking them takes a few minutes. This is an order of magnitude faster than most existing procedures. The measure of accuracy is the root mean square deviation (RMSD) with respect to the main-chain atoms after local superposition of target loop and predicted loop. Loops of up to nine residues length were modelled with a local RMSD <1 A and those of length up to 14 residues with an accuracy better than 2 A. The results were compared in detail with a thoroughly evaluated and tested ab initio method published recently and additionally with two further methods for a small loop test set. The LIP method produced very good predictions. In particular for longer loops it outperformed other methods.

  20. Uranyl Nitrate Flow Loop

    Energy Technology Data Exchange (ETDEWEB)

    Ladd-Lively, Jennifer L [ORNL

    2008-10-01

    The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO{sub 2}), uranium tetrafluoride (UF{sub 4}), and uranium hexafluoride (UF{sub 6})] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF{sub 6} product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion

  1. What Controls DNA Looping?

    Directory of Open Access Journals (Sweden)

    Pamela J. Perez

    2014-08-01

    Full Text Available The looping of DNA provides a means of communication between sequentially distant genomic sites that operate in tandem to express, copy, and repair the information encoded in the DNA base sequence. The short loops implicated in the expression of bacterial genes suggest that molecular factors other than the naturally stiff double helix are involved in bringing the interacting sites into close spatial proximity. New computational techniques that take direct account of the three-dimensional structures and fluctuations of protein and DNA allow us to examine the likely means of enhancing such communication. Here, we describe the application of these approaches to the looping of a 92 base-pair DNA segment between the headpieces of the tetrameric Escherichia coli Lac repressor protein. The distortions of the double helix induced by a second protein—the nonspecific nucleoid protein HU—increase the computed likelihood of looping by several orders of magnitude over that of DNA alone. Large-scale deformations of the repressor, sequence-dependent features in the DNA loop, and deformability of the DNA operators also enhance looping, although to lesser degrees. The correspondence between the predicted looping propensities and the ease of looping derived from gene-expression and single-molecule measurements lends credence to the derived structural picture.

  2. Development of Advanced In core Management Codes for Ulchin Unit 1, 2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hee; Park, Moon Gyu [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    As the first case of FRAMATOME`s plants, Ulchin Unit 1 Cycle 8 core was loaded with V5H fuel. Because of the heterogeneity in the axial enrichment of the V5H fuel, FRAMATOME`s 2-D in core management codes, CEDRIC-CARIN-ESTHER, are no longer valid to be used for in core management. In order to analyze Ulchin Unit 1 an 2 cores loaded with V5H fuel exactly, this study substituted them with WH`s In core-3D and Tote code. The previous IN CORE-Tote codes have been utilized on the HP workstation or the IBM mainframe which are not easily accessible by the site engineers and require the complicated manipulation in the computer network system. This study developed the PC-version of IN CORE-3D and Tote codes available in plants, including an interface code linking the data measured by the in core instrument system (RIC-KIT system) to IN CORE code. These codes reduce the time to manage in core and increase the economic benefits. We installed the developed codes in Ulchin Unit 1 and 2 and actually applied them to the core power distribution measurement performed during Cycle 8 power escalation tests. The results satisfied all limits of Technical Specification very well. The major contents of this study can be categorized as follows. 1. Analysis of the in core management codes. (a) Analysis of flux mapping system and measurement reduction algorithm. (b) Analysis of the methodology of in core management codes. 2. Development and verification of PC-version in core management codes. (a) Development of the measured-data processing code (C2I). (b) Development of PC-version IN CORE code. (c) Development of PC-version Tote code (d) Verification of the developed codes. 3. Application to core physics test of Ulchin until cycle 8. (a) Power distribution measurement at 75% and 100%. (author). 14 refs., figs., tabs.

  3. Construction of the blowdown and condensation loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Kyung; Song, Chul Kyung; Cho, Seok; Chun, S. Y.; Chung, Moon Ki

    1997-12-01

    The blowdown and condensation loop (B and C loop) has been constructed to get experimental data for designing the safety depressurization system (SDS) and steam sparger which are considered to implement in the Korea Next Generation Reactor (KNGR). In this report, system description on the B and C loop is given in detail, which includes the drawings and technical specification of each component, instrumentation and control system, and the operational procedures and the results of the performance testing. (author). 7 refs., 11 tabs., 48 figs.

  4. Loop-deformed Poincar\\'e algebra

    CERN Document Server

    Mielczarek, Jakub

    2013-01-01

    In this essay we present evidence suggesting that loop quantum gravity leads to deformation of the local Poincar\\'e algebra within the limit of high energies. This deformation is a consequence of quantum modification of effective off-shell hypersurface deformation algebra. Surprisingly, the form of deformation suggests that the signature of space-time changes from Lorentzian to Euclidean at large curvatures. We construct particular realization of the loop-deformed Poincar\\'e algebra and find that it can be related to curved momentum space, which indicates the relationship with recently introduced notion of relative locality. The presented findings open a new way of testing loop quantum gravity effects.

  5. Introduction to Loop Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Loop Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. This course will discuss operating principles and performance characteristics of a loop heat pipe. Topics include: 1) pressure profiles in the loop; 2) loop operating temperature; 3) operating temperature control; 4) loop startup; 4) loop shutdown; 5) loop transient behaviors; 6) sizing of loop components and determination of fluid inventory; 7) analytical modeling; 8) examples of flight applications; and 9) recent LHP developments.

  6. 导弹自动测试系统闭环量传与溯源方法%Closed-loop System of Valuation Transfer and Traceability for Missile Automatic Test System

    Institute of Scientific and Technical Information of China (English)

    赵海鹰

    2014-01-01

    Based on the MAP theory,closed-loop system of valuation transfer and traceability are used to missile automatic test system by the transfer standard device for identifying the error of whole test system, and enhanced the calibration ability of missile ATS.%介绍了利用“传递标准”装置对测试系统各参数实施“闭环量传”,以确定测试系统整体参数相对于计量单位工作标准的偏差的方法,实现对测试系统整体参数的校准与评定。

  7. A loop quantum multiverse?

    CERN Document Server

    Bojowald, Martin

    2013-01-01

    Inhomogeneous space-times in loop quantum cosmology have come under better control with recent advances in effective methods. Even highly inhomogeneous situations, for which multiverse scenarios provide extreme examples, can now be considered at least qualitatively.

  8. Blind loop syndrome

    Science.gov (United States)

    ... part of the stomach) and operations for extreme obesity As a complication of inflammatory bowel disease Diseases such as diabetes or scleroderma may slow down movement in a segment of the intestine, leading to blind loop syndrome.

  9. Diffusion of Wilson Loops

    CERN Document Server

    Brzoska, A M; Negele, J W; Thies, M

    2004-01-01

    A phenomenological analysis of the distribution of Wilson loops in SU(2) Yang-Mills theory is presented in which Wilson loop distributions are described as the result of a diffusion process on the group manifold. It is shown that, in the absence of forces, diffusion implies Casimir scaling and, conversely, exact Casimir scaling implies free diffusion. Screening processes occur if diffusion takes place in a potential. The crucial distinction between screening of fundamental and adjoint loops is formulated as a symmetry property related to the center symmetry of the underlying gauge theory. The results are expressed in terms of an effective Wilson loop action and compared with various limits of SU(2) Yang-Mills theory.

  10. From Loops to Surfaces

    CERN Document Server

    Neuberger, H

    2010-01-01

    The generating function for all antisymmetric characters of a Wilson loop matrix in SU(N) Yang Mills theory is the partition function of a fermion living on the curve describing the loop. This generalizes to fermion subsystems living on higher dimensional submanifolds, for example, surfaces. This write-up also contains some extra background, in response to some questions raised during the oral presentation.

  11. Numerical multi-loop integrals and applications

    CERN Document Server

    Freitas, Ayres

    2016-01-01

    Higher-order radiative corrections play an important role in precision studies of the electroweak and Higgs sector, as well as for the detailed understanding of large backgrounds to new physics searches. For corrections beyond the one-loop level and involving many independent mass and momentum scales, it is in general not possible to find analytic results, so that one needs to resort to numerical methods instead. This article presents an overview over a variety of numerical loop integration techniques, highlighting their range of applicability, suitability for automatization, and numerical precision and stability. In a second part of this article, the application of numerical loop integration methods in the area of electroweak precision tests is illustrated. Numerical methods were essential for obtaining full two-loop predictions for the most important precision observables within the Standard Model. The theoretical foundations for these corrections will be described in some detail, including aspects of the r...

  12. Genetic Programming with Simple Loops

    Institute of Scientific and Technical Information of China (English)

    QI Yuesheng; WANG Baozhong; KANG Lishan

    1999-01-01

    A kind of loop function LoopN inGenetic Programming (GP) is proposed.Different from other forms of loopfunction, such as While-Do and Repeat-Until, LoopNtakes only oneargument as its loop body and makes its loop body simply run N times,soinfinite loops will never happen. The problem of how to avoid too manylayers ofloops in Genetic Programming is also solved. The advantage ofLoopN in GP is shown bythe computational results in solving the mowerproblem.

  13. Loop electrosurgical excisional procedure.

    Science.gov (United States)

    Mayeaux, E J; Harper, M B

    1993-02-01

    Loop electrosurgical excisional procedure, or LEEP, also known as loop diathermy treatment, loop excision of the transformation zone (LETZ), and large loop excision of the transformation zone (LLETZ), is a new technique for outpatient diagnosis and treatment of dysplastic cervical lesions. This procedure produces good specimens for cytologic evaluation, carries a low risk of affecting childbearing ability, and is likely to replace cryotherapy or laser treatment for cervical neoplasias. LEEP uses low-current, high-frequency electrical generators and thin stainless steel or tungsten loops to excise either lesions or the entire transformation zone. Complication rates are comparable to cryotherapy or laser treatment methods and include bleeding, incomplete removal of the lesion, and cervical stenosis. Compared with other methods, the advantages of LEEP include: removal of abnormal tissue in a manner permitting cytologic study, low cost, ease of acquiring necessary skills, and the ability to treat lesions with fewer visits. Patient acceptance of the procedure is high. Widespread use of LEEP by family physicians can be expected.

  14. Structural thermal model tests on exposed facility of Japanese experiment module for international space station `Alpha`. 1st Report. Static load/fluid loop performance test and modal survey; Kokusai uchu station `Alpha` JEM bakurobu no netsukozo model shiken. 1. Seikaju shiken, ryudo tokusei shiken oyoboi modal survey

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M.; Nakao, K.; Ikami, T.; Arafune, K.; Nakahara, S. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1995-03-01

    Static load/fluid loop performance test and modal survey results among structural thermal model (STM) tests of an exposed facility are reported for the Japanese Experiment Module (JEM) mounted on the international space station `Alpha`. In the static load test, the strength and rigidity of STM were ascertained to be reasonable against the loads applied to the facility at launch and reentry, and the structural mathematical model was also reasonable based on the comparison between test and analytical results. In the fluid performance test to verify the fundamental fluid loop performance of the thermal control system for the exposed facility, the test results on pressure losses of STM which has a strong effect on the accuracy of coolant fluid distribution at each branch point, well agreed with analytical ones. In the modal survey to verify dynamic characteristics of the structural mathematical model, some appropriate modal parameters were obtained by modal analysis of test data, and the survey results also well agreed with analytical ones on the structural mathematical model. 1 ref., 10 figs., 2 tabs.

  15. Loops in Twistor Space

    CERN Document Server

    Bena, I; Kosower, D A; Roiban, R; Bena, Iosif; Bern, Zvi; Kosower, David A.; Roiban, Radu

    2004-01-01

    We elucidate the one-loop twistor-space structure corresponding to momentum-space MHV diagrams. We also discuss the infrared divergences, and argue that only a limited set of MHV diagrams contain them. We show how to introduce a twistor-space regulator corresponding to dimensional regularization for the infrared-divergent diagrams. We also evaluate explicitly the `holomorphic anomaly' pointed out by Cachazo, Svrcek, and Witten, and use the result to define modified differential operators which can be used to probe the twistor-space structure of one-loop amplitudes.

  16. Closed Loop Subspace Identification

    Directory of Open Access Journals (Sweden)

    Geir W. Nilsen

    2005-07-01

    Full Text Available A new three step closed loop subspace identifications algorithm based on an already existing algorithm and the Kalman filter properties is presented. The Kalman filter contains noise free states which implies that the states and innovation are uneorre lated. The idea is that a Kalman filter found by a good subspace identification algorithm will give an output which is sufficiently uncorrelated with the noise on the output of the actual process. Using feedback from the output of the estimated Kalman filter in the closed loop system a subspace identification algorithm can be used to estimate an unbiased model.

  17. Loop Quantum Gravity

    CERN Document Server

    Chiou, Dah-Wei

    2014-01-01

    This article presents an "in-a-nutshell" yet self-contained introductory review on loop quantum gravity (LQG) -- a background-independent, nonperturbative approach to a consistent quantum theory of gravity. Instead of rigorous and systematic derivations, it aims to provide a general picture of LQG, placing emphasis on the fundamental ideas and their significance. The canonical formulation of LQG, as the central topic of the article, is presented in a logically orderly fashion with moderate details, while the spin foam theory, black hole thermodynamics, and loop quantum cosmology are covered briefly. Current directions and open issues are also summarized.

  18. Thermo-optical characterization of a low-background infrared chamber and wideband infrared scene projector (WISP) array for hardware-in-the-loop testing

    Science.gov (United States)

    Lippert, Jack R.; Flynn, David S.; Jones, Lawrence E.; Kircher, James R.

    1999-07-01

    The KHILS Vacuum Cold Chamber (KVACC) provides the capability of testing IR seekers with scenes involving a `cold' background, more closely simulating a high altitude/exoatmospheric engagement. During the past year, a gaseous helium refrigeration system has been installed to simplify the logistics of cooling the chamber. An antechamber has also been installed to serve as a chamber for the sensor under test. A WISP array was installed in the Source Chamber. A thermal control system was developed by connecting the array to a cold surface by way of a thermal choke, then actively controlling the temperature with heating elements. This made it possible to operate the array at user selected, stable substrate temperatures ranging from ambient temperature to below 150 K. This capability makes it possible to select the infrared background level that the array operates at, and to operate with background levels that are adequate for testing the high altitude/exoatmospheric engagements. WISP arrays were designed for room temperature operation, but predicted performance at reduced temperatures appears acceptable. Tests were performed with a Phase I prototype WISP array inside the KVACC Source Chamber. Data on this array's radiometric response at various substrate temperatures are presented. It is demonstrated that the arrays can be operated at substrate temperatures as low as 145 K. Currently two Phase 3 WISP arrays and a dichroic beam combiner are being installed in the Source Chamber for 2- color testing.

  19. Delay locked loop integrated circuit.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  20. Meyer's loop asymmetry and language lateralisation in epilepsy

    OpenAIRE

    Nowell, Mark; Vos, Sjoerd B; Sidhu, Meneka; Wilcoxen, Kaitlin; Sargsyan, Narek; Ourselin, Sebastien; Duncan, John S.

    2015-01-01

    Objectives Several studies have suggested an asymmetry in Meyer's loop in individuals, with the left loop anterior to the right. In this study we test the hypothesis that there is an association between Meyer's loop asymmetry (MLA) and language lateralisation. Methods 57 patients with epilepsy were identified with language functional MRI (fMRI) and diffusion MRI acquisition. Language lateralisation indices from fMRI(LI) and optic radiation and arcuate fasciculus probabilistic tractography was...

  1. Characterization study and five-cycle tests in a fixed-bed reactor of titania-supported nickel oxide as oxygen carriers for the chemical-looping combustion of methane.

    Science.gov (United States)

    Corbella, Beatriz M; de Diego, Luis F; García-Labiano, Francisco; Adánez, Juan; Palaciost, José M

    2005-08-01

    Recent investigations have shown that in the combustion of carbonaceous compounds CO2 and NOx emissions to the atmosphere can be substantially reduced by using a two stage chemical-looping process. In this process, the reduction stage is undertaken in a first reactor in which the framework oxygen of a reducible inorganic oxide is used, instead of the usual atmospheric oxygen, for the combustion of a carbonaceous compound, for instance, methane. The outlet gas from this reactor is mostly composed of CO2 and steam as reaction products and further separation of these two components can be carried out easily by simple condensation of steam. Then, the oxygen carrier found in a reduced state is transported to a second reactor in which carrier regeneration with air takes place at relatively low temperatures, consequently preventing the formation of thermal NOx. Afterward, the regenerated carrier is carried to the first reactor to reinitiate a new cycle and so on for a number of repetitive cycles, while the carrier is able to withstand the severe chemical and thermal stresses involved in every cycle. In this paper, the performance of titania-supported nickel oxides has been investigated in a fixed-bed reactor as oxygen carriers for chemical-looping combustion of methane. Samples with different nickel oxide contents were prepared by successive incipient wet impregnations, and their performance as oxygen carriers was investigated at 900 degrees C and atmospheric pressure in five-cycle fixed-bed reactor tests using pure methane and pure air for the respective reduction and regeneration stages. The evolution of the outlet gas composition in each stage was followed by gas chromatography, and the involved chemical, structural, and textural changes of the carrier in the reactor bed were studied by using different characterization techniques. From the study, it is deduced that the reactivity of these nickel-based oxygen carriers is in the two involved stages and almost independent

  2. Loop Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Rovelli Carlo

    1998-01-01

    Full Text Available The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. Research in loop quantum gravity today forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained are: (i The computation of the physical spectra of geometrical quantities such as area and volume, which yields quantitative predictions on Planck-scale physics. (ii A derivation of the Bekenstein-Hawking black hole entropy formula. (iii An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, over-completeness of the loop basis, implementation of reality conditions have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.

  3. Reversible hysteresis loop tuning

    Science.gov (United States)

    Berger, A.; Binek, Ch.; Margulies, D. T.; Moser, A.; Fullerton, E. E.

    2006-02-01

    We utilize antiferromagnetically coupled bilayer structures to magnetically tune hysteresis loop properties. Key element of this approach is the non-overlapping switching field distribution of the two magnetic layers that make up the system: a hard magnetic CoPtCrB layer (HL) and a soft magnetic CoCr layer (SL). Both layers are coupled antiferromagnetically through an only 0.6-nm-thick Ru interlayer. The non-overlapping switching field distribution allows the measurement of magnetization reversal in the SL at low fields while keeping the magnetization state of the HL unperturbed. Applying an appropriate high field or high field sequence changes the magnetic state of the HL, which then influences the SL magnetization reversal due to the interlayer coupling. In this way, the position and shape of the SL hysteresis loop can be changed or tuned in a fully reversible and highly effective manner. Here, we study specifically how the SL hysteresis loop characteristics change as we move the HL through an entire high field hysteresis loop sequence.

  4. Results of aircraft open-loop tests of an experimental magnetic leader cable system for guidance during roll-out and turnoff

    Science.gov (United States)

    Bundick, W. Thomas; Middleton, David B.; Poole, William L.

    1990-01-01

    An experimental magnetic leader cable (MLC) system designed to measure aircraft lateral displacement from centerline and heading relative to centerline during rollout, turnoff, and taxi was tested at NASA's Wallops Flight Facility using NASA's Transport System Research Vehicle (TSRV), a modified B-737. The MLC system consisted of ground equipment that produced a magnetic field about a wire along runway centerline and airborne equipment that detected the strength and direction of this field and computed displacement and heading. Results of these tests indicate that estimates of aircraft displacement from centerline produced by the magnetic leader cable system using either of the two algorithms appear to be adequate for use by an automatic control system during rollout, turnoff, and taxi. Estimates of heading, however, are not sufficiently accurate for use, probably because of distortion of the magnetic field by the metal aircraft.

  5. Two-loop and n-loop eikonal vertex corrections

    OpenAIRE

    Kidonakis, Nikolaos

    2003-01-01

    I present calculations of two-loop vertex corrections with massive and massless partons in the eikonal approximation. I show that the $n$-loop result for the UV poles can be given in terms of the one-loop calculation.

  6. Saccade learning with concurrent cortical and subcortical basal ganglia loops

    Directory of Open Access Journals (Sweden)

    Steve eN'guyen

    2014-04-01

    Full Text Available The Basal Ganglia is a central structure involved in multiple cortical and subcortical loops. Some of these loops are believed to be responsible for saccade target selection. We study here how the very specific structural relationships of these saccadic loops can affect the ability of learning spatial and feature-based tasks.We propose a model of saccade generation with reinforcement learning capabilities based onour previous basal ganglia and superior colliculus models. It is structured around the interactions of two parallel cortico-basal loops and one tecto-basal loop. The two cortical loops separately deal with spatial and non-spatial information to select targets in a concurrent way. The subcortical loop is used to make the final target selection leading to the production of thesaccade. These different loops may work in concert or disturb each other regarding reward maximization. Interactions between these loops and their learning capabilities are tested on different saccade tasks.The results show the ability of this model to correctly learn basic target selection based on different criteria (spatial or not. Moreover the model reproduces and explains training dependent express saccades toward targets based on a spatial criterion. Finally, the model predicts that in absence of prefrontal control, the spatial loop should dominate.

  7. Local loop near-rings

    OpenAIRE

    Franetič, Damir

    2015-01-01

    We study loop near-rings, a generalization of near-rings, where the additive structure is not necessarily associative. We introduce local loop near-rings and prove a useful detection principle for localness.

  8. Long-term pumping test to study the impact of an open-loop geothermal system on seawater intrusion in a coastal aquifer: the case study of Bari (Southern Italy)

    Science.gov (United States)

    Clementina Caputo, Maria; Masciale, Rita; Masciopinto, Costantino; De Carlo, Lorenzo

    2016-04-01

    The high cost and scarcity of fossil fuels have promoted the increased use of natural heat for a number of direct applications. Just as for fossil fuels, the exploitation of geothermal energy should consider its environmental impact and sustainability. Particular attention deserves the so-called open loop geothermal groundwater heat pump (GWHP) system, which uses groundwater as geothermal fluid. From an economic point of view, the implementation of this kind of geothermal system is particularly attractive in coastal areas, which have generally shallow aquifers. Anyway the potential problem of seawater intrusion has led to laws that restrict the use of groundwater. The scarcity of freshwater could be a major impediment for the utilization of geothermal resources. In this study a new methodology has been proposed. It was based on an experimental approach to characterize a coastal area in order to exploit the low-enthalpy geothermal resource. The coastal karst and fractured aquifer near Bari, in Southern Italy, was selected for this purpose. For the purpose of investigating the influence of an open-loop GWHP system on the seawater intrusion, a long-term pumping test was performed. The test simulated the effects of a prolonged withdrawal on the chemical-physical groundwater characteristics of the studied aquifer portion. The duration of the test was programmed in 16 days, and it was performed with a constant pumping flowrate of 50 m3/h. The extracted water was outflowed into an adjacent artificial channel, by means of a piping system. Water depth, temperature and electrical conductivity of the pumped water were monitored for 37 days, including also some days before and after the pumping duration. The monitored parameters, collected in the pumping and in five observation wells placed 160 m down-gradient with respect to the groundwater flow direction, have been used to estimate different scenarios of the impact of the GWHP system on the seawater intrusion by mean of a

  9. Hybrid Combustion-Gasification Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Herbert Andrus; Gregory Burns; John Chiu; Gregory Lijedahl; Peter Stromberg; Paul Thibeault

    2009-01-07

    } separation, and also syngas production from coal with the calcium sulfide (CaS)/calcium sulfate (CaSO{sub 4}) loop utilizing the PDU facility. The results of Phase I were reported in Reference 1, 'Hybrid Combustion-Gasification Chemical Looping Coal Power Development Technology Development Phase I Report' The objective for Phase II was to develop the carbonate loop--lime (CaO)/calcium carbonate (CaCO{sub 3}) loop, integrate it with the gasification loop from Phase I, and ultimately demonstrate the feasibility of hydrogen production from the combined loops. The results of this program were reported in Reference 3, 'Hybrid Combustion-Gasification Chemical Looping Coal Power Development Technology Development Phase II Report'. The objective of Phase III is to operate the pilot plant to obtain enough engineering information to design a prototype of the commercial Chemical Looping concept. The activities include modifications to the Phase II Chemical Looping PDU, solids transportation studies, control and instrumentation studies and additional cold flow modeling. The deliverable is a report making recommendations for preliminary design guidelines for the prototype plant, results from the pilot plant testing and an update of the commercial plant economic estimates.

  10. Inflation and Loop Quantum Cosmology

    CERN Document Server

    Barrau, Aurelien

    2010-01-01

    On the one hand, inflation is an extremely convincing scenario: it solves most cosmological paradoxes and generates fluctuations that became the seeds for the growth of structures. It, however, suffers from a "naturalness" problem: generating initial conditions for inflation is far from easy. On the other hand, loop quantum cosmology is very successful: it solves the Big Bang singularity through a non-perturbative and background-independent quantization of general relativity. It, however, suffers from a key drawback: it is extremely difficult to test. Recent results can let us hope that inflation and LQC could mutually cure those pathologies: LQC seems to naturally generate inflation and inflation could allow us to test LQC.

  11. Issues and Feasibility Demonstration of Positioning Closed Loop Control for the CLIC Supporting System Using a Test Mock-up with Five Degrees of Freedom

    CERN Document Server

    Sosin, M; Chritin, N; Griffet, S; Kemppinen, J; Mainaud Durand, H; Rude, V; Sterbini, G

    2012-01-01

    Since several years, CERN is studying the feasibility of building a high energy e+ e- linear collider: the CLIC (Compact LInear Collider). One of the challenges of such a collider is the pre-alignment precision and accuracy requirement on the transverse positions of the linac components, which is typically 14 μm over a window of 200 m. To ensure the possibility of positioning within such tight constraints, CERN Beams Department’s Survey team has worked intensively at developing the methods and technology needed to achieve that objective. This paper describes activities which were performed on a test bench (mock-up) with five degrees of freedom (DOF) for the qualification of control algorithms for the CLIC supporting system active-pre-alignment. Present understanding, lessons learned (“know how”), issues of sensors noise and mechanical components nonlinearities are presented.

  12. Simulation of short-term pressure regulation during the tilt test in a coupled 3D-0D closed-loop model of the circulation.

    Science.gov (United States)

    Lau, Kevin D; Figueroa, C Alberto

    2015-08-01

    Short-term fluctuations in arterial pressures arising from normal physiological function are buffered by a negative feedback system known as the arterial baroreflex. Initiated by altered biomechanical stretch in the vessel wall, the baroreflex coordinates a systemic response that alters heart rate, cardiac contractility and peripheral vessel vasoconstriction. In this work, a coupled 3D-0D formulation for the short-term pressure regulation of the systemic circulation is presented. Including the baroreflex feedback mechanisms, a patient-specific model of the large arteries is subjected to a simulated head up tilt test. Comparative simulations with and without baroreflex control highlight the critical role that the baroreflex has in regulating variations in pressures within the systemic circulation.

  13. Iterative LQG Controller Design Through Closed-Loop Identification

    Science.gov (United States)

    Hsiao, Min-Hung; Huang, Jen-Kuang; Cox, David E.

    1996-01-01

    This paper presents an iterative Linear Quadratic Gaussian (LQG) controller design approach for a linear stochastic system with an uncertain open-loop model and unknown noise statistics. This approach consists of closed-loop identification and controller redesign cycles. In each cycle, the closed-loop identification method is used to identify an open-loop model and a steady-state Kalman filter gain from closed-loop input/output test data obtained by using a feedback LQG controller designed from the previous cycle. Then the identified open-loop model is used to redesign the state feedback. The state feedback and the identified Kalman filter gain are used to form an updated LQC controller for the next cycle. This iterative process continues until the updated controller converges. The proposed controller design is demonstrated by numerical simulations and experiments on a highly unstable large-gap magnetic suspension system.

  14. On the extended loop calculus

    CERN Document Server

    Griego, J R

    1995-01-01

    Some features of extended loops are considered. In particular, the behaviour under diffeomorphism transformations of the wavefunctions with support on the extended loop space are studied. The basis of a method to obtain analytical expressions of diffeomorphism invariants via extended loops are settled. Applications to knot theory and quantum gravity are considered.

  15. Closing global material loops

    DEFF Research Database (Denmark)

    Prosman, Ernst-Jan; Wæhrens, Brian Vejrum; Liotta, Giacomo

    2017-01-01

    Replacing virgin materials with waste materials, a practice known as Industrial Symbiosis (IS), has been identified as a key strategy for closing material loops. This article adopts a critical view on geographic proximity and external coordinators – two key enablers of IS. By ‘uncovering’ a case...... where both enablers are absent, this study seeks to explore firm-level challenges of IS. We adopt an exploratory case study approach at a cement manufacturer who engages in cross-border IS without the support of external coordinators. Our research presents insights into two key areas of IS: 1) setting...... for geographic proximity and external coordinators. In doing so, our insights into firm-level challenges of long-distance IS exchanges contribute to closing global material loops by increasing the number of potential circular pathways....

  16. Testing Proposed Neuronal Models of Effective Connectivity Within the Cortico-basal Ganglia-thalamo-cortical Loop During Loss of Consciousness.

    Science.gov (United States)

    Crone, Julia Sophia; Lutkenhoff, Evan Scott; Bio, Branden Joseph; Laureys, Steven; Monti, Martin Max

    2017-04-01

    In recent years, a number of brain regions and connectivity patterns have been proposed to be crucial for loss and recovery of consciousness but have not been compared in detail. In a 3 T resting-state functional magnetic resonance imaging paradigm, we test the plausibility of these different neuronal models derived from theoretical and empirical knowledge. Specifically, we assess the fit of each model to the dynamic change in effective connectivity between specific cortical and subcortical regions at different consecutive levels of propofol-induced sedation by employing spectral dynamic causal modeling. Surprisingly, our findings indicate that proposed models of impaired consciousness do not fit the observed patterns of effective connectivity. Rather, the data show that loss of consciousness, at least in the context of propofol-induced sedation, is marked by a breakdown of corticopetal projections from the globus pallidus. Effective connectivity between the globus pallidus and the ventral posterior cingulate cortex, present during wakefulness, fades in the transition from lightly sedated to full loss of consciousness and returns gradually as consciousness recovers, thereby, demonstrating the dynamic shift in brain architecture of the posterior cingulate "hub" during changing states of consciousness. These findings highlight the functional role of a previously underappreciated direct pallido-cortical connectivity in supporting consciousness. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. An Application Example Analysis of Quality Assurance Program for STELLA(Sodium Integral Effect Test Loop for Safety Simulation and Assessment) Project

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Minhwan; Gam, Dayoung; Eoh, Jae-Hyuk; Jeong, Ji-Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    KAERI has been conducting various basic R and D activities in the field of nuclear technology. In addition, KAERI is now participating in the Generation IV International Forum (GIF), preparing for the development of key technologies for Generation IV nuclear energy system, including Sodium cooled Fast Reactor (SFR) development. All of the key technologies for SFR development need an appropriate level of QA activities to achieve the GIF safety and performance objectives. Therefore, QA activities have been conducted as an essential part of the national SFR project. As a result, QAM (Quality Assurance Manual) and QAP (Quality Assurance Procedures) have been developed for the SFR project, which are based on ASME NQA-1, KEPIC QAP and the GIF Quality Management System Guidelines. In this work, the introduction background and application examples of the QA program for the STELLA project were investigated. Application of the QA for the STELLA project has great significance because the QA has been mainly applied for the nuclear power plant area in operation, which helps ensure the reliability of the test data and completeness of the research performance. Nevertheless, developing more appropriate QA procedures remains a major task because some parts of them are not applicable to the Na-experiment.

  18. Loop Quantum Cosmology

    Directory of Open Access Journals (Sweden)

    Bojowald Martin

    2008-07-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time.

  19. Loop Quantum Cosmology

    Directory of Open Access Journals (Sweden)

    Bojowald Martin

    2005-12-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical space-time inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding space-time is then modified. One particular realization is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. Main effects are introduced into effective classical equations which allow to avoid interpretational problems of quantum theory. They give rise to new kinds of early universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function which allows to extend space-time beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of space-time arising in loop quantum gravity and its application to cosmology sheds new light on more general issues such as time.

  20. PAR Loop Schedule Review

    Energy Technology Data Exchange (ETDEWEB)

    Schaffer, Jr.; W.F.

    1958-04-30

    The schedule for the installation of the PAR slurry loop experiment in the South Facility of the ORR has been reviewed and revised. The design, fabrications and Installation is approximately two weeks behind schedule at this time due to many factors; however, indications are that this time can be made up. Design is estimated to be 75% complete, fabrication 32% complete and installation 12% complete.

  1. Verification of Loop Diagnostics

    Science.gov (United States)

    Winebarger, A.; Lionello, R.; Mok, Y.; Linker, J.; Mikic, Z.

    2014-01-01

    Many different techniques have been used to characterize the plasma in the solar corona: density-sensitive spectral line ratios are used to infer the density, the evolution of coronal structures in different passbands is used to infer the temperature evolution, and the simultaneous intensities measured in multiple passbands are used to determine the emission measure. All these analysis techniques assume that the intensity of the structures can be isolated through background subtraction. In this paper, we use simulated observations from a 3D hydrodynamic simulation of a coronal active region to verify these diagnostics. The density and temperature from the simulation are used to generate images in several passbands and spectral lines. We identify loop structures in the simulated images and calculate the loop background. We then determine the density, temperature and emission measure distribution as a function of time from the observations and compare with the true temperature and density of the loop. We find that the overall characteristics of the temperature, density, and emission measure are recovered by the analysis methods, but the details of the true temperature and density are not. For instance, the emission measure curves calculated from the simulated observations are much broader than the true emission measure distribution, though the average temperature evolution is similar. These differences are due, in part, to inadequate background subtraction, but also indicate a limitation of the analysis methods.

  2. Cosmic string loop microlensing

    Science.gov (United States)

    Bloomfield, Jolyon K.; Chernoff, David F.

    2014-06-01

    Cosmic superstring loops within the galaxy microlens background point sources lying close to the observer-string line of sight. For suitable alignments, multiple paths coexist and the (achromatic) flux enhancement is a factor of two. We explore this unique type of lensing by numerically solving for geodesics that extend from source to observer as they pass near an oscillating string. We characterize the duration of the flux doubling and the scale of the image splitting. We probe and confirm the existence of a variety of fundamental effects predicted from previous analyses of the static infinite straight string: the deficit angle, the Kaiser-Stebbins effect, and the scale of the impact parameter required to produce microlensing. Our quantitative results for dynamical loops vary by O(1) factors with respect to estimates based on infinite straight strings for a given impact parameter. A number of new features are identified in the computed microlensing solutions. Our results suggest that optical microlensing can offer a new and potentially powerful methodology for searches for superstring loop relics of the inflationary era.

  3. Lidar Sensor Performance in Closed-Loop Flight Testing of the Morpheus Rocket-Propelled Lander to a Lunar-Like Hazard Field

    Science.gov (United States)

    Roback, V. Eric; Pierrottet, Diego F.; Amzajerdian, Farzin; Barnes, Bruce W.; Bulyshev, Alexander E.; Hines, Glenn D.; Petway, Larry B.; Brewster, Paul F.; Kempton, Kevin S.

    2015-01-01

    into the ALHAT navigation filter to provide lander guidance to the safe site. The flight tests served as the culmination of the TRL 6 journey for the ALHAT system and included launch from a pad situated at the NASA-Kennedy Space Center Shuttle Landing Facility (SLF) runway, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range just off the North end of the runway. The tests both confirmed the expected performance and also revealed several challenges present in the flight-like environment which will feed into future TRL advancement of the sensors. Guidance provided by the ALHAT system was impeded in portions of the trajectory and intermittent near the end of the trajectory due to optical effects arising from air heated by the rocket engine. The Flash Lidar identified hazards as small as 30 cm from the maximum slant range of 450 m which Morpheus could provide; however, it was occasionally susceptible to an increase in range noise due to scintillation arising from air heated by the Morpheus rocket engine which entered its Field-of-View (FOV). The Flash Lidar was also susceptible to pre-triggering, during the HRN phase, on a dust cloud created during launch and transported down-range by the wind. The NDL provided velocity and range measurements to the expected accuracy levels yet it was also susceptible to signal degradation due to air heated by the rocket engine. The LA, operating with a degraded transmitter laser, also showed signal attenuation over a few seconds at a specific phase of the flight due to the heat plume generated by the rocket engine.

  4. LoopIng: a template-based tool for predicting the structure of protein loops.

    KAUST Repository

    Messih, Mario Abdel

    2015-08-06

    Predicting the structure of protein loops is very challenging, mainly because they are not necessarily subject to strong evolutionary pressure. This implies that, unlike the rest of the protein, standard homology modeling techniques are not very effective in modeling their structure. However, loops are often involved in protein function, hence inferring their structure is important for predicting protein structure as well as function.We describe a method, LoopIng, based on the Random Forest automated learning technique, which, given a target loop, selects a structural template for it from a database of loop candidates. Compared to the most recently available methods, LoopIng is able to achieve similar accuracy for short loops (4-10 residues) and significant enhancements for long loops (11-20 residues). The quality of the predictions is robust to errors that unavoidably affect the stem regions when these are modeled. The method returns a confidence score for the predicted template loops and has the advantage of being very fast (on average: 1 min/loop).www.biocomputing.it/loopinganna.tramontano@uniroma1.itSupplementary data are available at Bioinformatics online.

  5. Research on General Testing Platform for Embedded Software Under the Hardware-in-the-Loop Environment%半实物环境下嵌入式软件通用测试平台研究

    Institute of Scientific and Technical Information of China (English)

    郭旺; 丁晓明; 唐海鹏; 蔡东容; 顾卫华

    2015-01-01

    As the scale of embedded software becomes bigger day by day ,its structure gets more and more complex .Currently ,the testing system is generally developed for aspecific embedded software and its de‐velopment has tostart from scratch ,for no general platform is available w hich can support the test .In this paper ,a general testing platform frame under the hardware‐in‐the‐loop environmentis proposed .Cross‐lan‐guage source code analysis is made based on the application of Eclipse CDT/JDT .XML document is used as the exchange platform of the testing data .With the replace ability of the target machine ,a general plat‐form with high‐degree automation is realized .The functions of the testing platform include source code a‐nalysis ,probe insertion by test type ,automatic compilation and testing data analysis .%嵌入式软件规模日益增大,结构也越来越复杂。当前嵌入式软件测试系统通常针对特定被测软件,从底层做起,没有一个通用平台提供支持。本文提出了一个半实物环境下嵌入式软件通用测试平台框架,采用基于 Eclipse CDT/JDT的跨语言源代码分析,使用XML文档作为测试数据交换介质,结合半实物环境下目标机的可替换性,实现了测试平台的通用性,自动化程度较高。根据该框架建成的测试平台,支持对被测程序进行源代码分析、按类插桩、自动编译、测试数据分析等操作。

  6. Improving Loop Dependence Analysis

    DEFF Research Database (Denmark)

    Jensen, Nicklas Bo; Karlsson, Sven

    2017-01-01

    Programmers can no longer depend on new processors to have significantly improved single-thread performance. Instead, gains have to come from other sources such as the compiler and its optimization passes. Advanced passes make use of information on the dependencies related to loops. We improve...... the quality of that information by reusing the information given by the programmer for parallelization. We have implemented a prototype based on GCC into which we also add a new optimization pass. Our approach improves the amount of correctly classified dependencies resulting in 46% average improvement...

  7. Closing the loop.

    Science.gov (United States)

    Dassau, E; Atlas, E; Phillip, M

    2011-02-01

    Closed-loop algorithms can be found in every aspect of everyday modern life. Automation and control are used constantly to provide safety and to improve quality of life. Closed-loop systems and algorithms can be found in home appliances, automobiles, aviation and more. Can one imagine nowadays driving a car without ABS, cruise control or even anti-sliding control? Similar principles of automation and control can be used in the management of diabetes mellitus (DM). The idea of an algorithmic/technological way to control glycaemia is not new and has been researched for more than four decades. However, recent improvements in both glucose-sensing technology and insulin delivery together with advanced control and systems engineering made this dream of an artificial pancreas possible. The artificial pancreas may be the next big step in the treatment of DM since the use of insulin analogues. An artificial pancreas can be described as internal or external devices that use continuous glucose measurements to automatically manage exogenous insulin delivery with or without other hormones in an attempt to restore glucose regulation in individuals with DM using a control algorithm. This device as described can be internal or external; can use different types of control algorithms with bi-hormonal or uni-hormonal design; and can utilise different ways to administer them. The different designs and implementations have transitioned recently from in silico simulations to clinical evaluation stage with practical applications in mind. This may mark the beginning of a new era in diabetes management with the introduction of semi-closed-loop systems that can prevent or minimise nocturnal hypoglycaemia, to hybrid systems that will manage blood glucose (BG) levels with minimal user intervention to finally fully automated systems that will take the user out of the loop. More and more clinical trials will be needed for the artificial pancreas to become a reality but initial encouraging

  8. Loop expansion and the bosonic representation of loop quantum gravity

    Science.gov (United States)

    Bianchi, E.; Guglielmon, J.; Hackl, L.; Yokomizo, N.

    2016-10-01

    We introduce a new loop expansion that provides a resolution of the identity in the Hilbert space of loop quantum gravity on a fixed graph. We work in the bosonic representation obtained by the canonical quantization of the spinorial formalism. The resolution of the identity gives a tool for implementing the projection of states in the full bosonic representation onto the space of solutions to the Gauss and area matching constraints of loop quantum gravity. This procedure is particularly efficient in the semiclassical regime, leading to explicit expressions for the loop expansions of coherent, heat kernel and squeezed states.

  9. Loop expansion and the bosonic representation of loop quantum gravity

    CERN Document Server

    Bianchi, Eugenio; Hackl, Lucas; Yokomizo, Nelson

    2016-01-01

    We introduce a new loop expansion that provides a resolution of the identity in the Hilbert space of loop quantum gravity on a fixed graph. We work in the bosonic representation obtained by the canonical quantization of the spinorial formalism. The resolution of the identity gives a tool for implementing the projection of states in the full bosonic representation onto the space of solutions to the Gauss and area matching constraints of loop quantum gravity. This procedure is particularly efficient in the semiclassical regime, leading to explicit expressions for the loop expansions of coherent, heat kernel and squeezed states.

  10. Vapor Compressor Driven Hybrid Two-Phase Loop Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I project successfully demonstrated the feasibility of the vapor compression hybrid two-phase loop (VCHTPL). The test results showed the high...

  11. Multiple coronary arterial loops as a cause of myocardial ischemia

    Science.gov (United States)

    Bashour, Tali T.; Mansour, Nagi N.; Lee, Damon

    1993-01-01

    A case of long-standing angina with ischemia documented by exercise testing and thallium scintigraphy in a patient who had multiple proximal loops in all three major coronary arteries in the absence of luminal stenosis, is reported.

  12. Condition Monitoring of Control Loops

    OpenAIRE

    Horch, Alexander

    2000-01-01

    The main concern of this work is the development of methodsfor automatic condition monitoring of control loops withapplication to the process industry. By condition monitoringboth detection and diagnosis of malfunctioning control loops isunderstood, using normal operating data and a minimum amount ofprocess knowledge. The use of indices for quantifying loop performance is dealtwith in the first part of the thesis. The starting point is anindex proposed by Harris (1989). This index has been mo...

  13. Loop Heat Pipe Startup Behaviors

    Science.gov (United States)

    Ku, Jentung

    2016-01-01

    A loop heat pipe must start successfully before it can commence its service. The startup transient represents one of the most complex phenomena in the loop heat pipe operation. This paper discusses various aspects of loop heat pipe startup behaviors. Topics include the four startup scenarios, the initial fluid distribution between the evaporator and reservoir that determines the startup scenario, factors that affect the fluid distribution between the evaporator and reservoir, difficulties encountered during the low power startup, and methods to enhance the startup success. Also addressed are the pressure spike and pressure surge during the startup transient, and repeated cycles of loop startup and shutdown under certain conditions.

  14. 线粒体D-loop序列变异与东方鲀属鱼类系统发育%PHYLOGENETIC RELATIONSHIPS OF THE GENUS TAKIFUGU (TETRAODONTIFORMES, TETRAODONTIDAE) TESTED BY mtDNA D-LOOP REGION SEQUENCE VARIATIONS

    Institute of Scientific and Technical Information of China (English)

    张玉波; 甘小妮; 何舜平

    2009-01-01

    The pufferfishes of the genus Takifugu are East Asian fish, mainly distribute along the coastal region in western part of the Sea of Japan and the East China. This genus is attached more and more importance to researchers, for Takifugu rubripes, which is one species in it, has been a new model fish in the post-genomic era. The details of the phylogenetic relationships within the genus remain unresolved. In the present paper, mitochondrial D-loop sequences of 11 species of the genus Takifugu were determined and analyzed to test the present phylogenetic hypotheses. The sequence saturation analysis was inferred from the shape of the trend line, which indicated that the sequence was unsaturated and could be used in the following phylogenetic analysis. After alignment, the sequence compositions and variations were analyzed by using MEGA 3 software. There were 841 sites, among which 395 sites were variable, and 267 were informative. There was significant difference in base compositional bias between the ingroup and the outgroup species. The uncorrected p-distance matrix obtained from the analysis of the alignment of all D-loop sequences showed that the relationships among the different species were closely. Neighbor-joining, Maximum Parsimony, Maximum Likelihood and Bayesian methods were employed for phylogenetics analysis, respectively. Due to the SH test about the phylogeny hypothesis, we chose the Bayesian tree as our best tree in this paper. The Bayesian tree has described a more clearly phylogeny and the analysis also has pointed out the basal species in the genus. The results indicate that the genus form a monophyletic groups, with the sister group consisted by T. oblongus and T. alboplumbeus is the basal group of the genus. Our results also show some confusion about the taxonomy in the genus, according to the data and combined analysis with the morphological characters, we suppose some species are in fact synonymous in this genus, which suggest that the taxonomy

  15. Inductance loop and partial

    CERN Document Server

    Paul, Clayton R

    2010-01-01

    "Inductance is an unprecedented text, thoroughly discussing "loop" inductance as well as the increasingly important "partial" inductance. These concepts and their proper calculation are crucial in designing modern high-speed digital systems. World-renowned leader in electromagnetics Clayton Paul provides the knowledge and tools necessary to understand and calculate inductance." "With the present and increasing emphasis on high-speed digital systems and high-frequency analog systems, it is imperative that system designers develop an intimate understanding of the concepts and methods in this book. Inductance is a much-needed textbook designed for senior and graduate-level engineering students, as well as a hands-on guide for working engineers and professionals engaged in the design of high-speed digital and high-frequency analog systems."--Jacket.

  16. Loop Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Rovelli Carlo

    2008-07-01

    Full Text Available The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime, is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler’s “spacetime foam” intuition. (iii Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv A derivation of the Bekenstein–Hawking black-hole entropy. (v Low-energy calculations, yielding n-point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.

  17. Loop-loop interactions govern multiple steps in indole-3-glycerol phosphate synthase catalysis.

    Science.gov (United States)

    Zaccardi, Margot J; O'Rourke, Kathleen F; Yezdimer, Eric M; Loggia, Laura J; Woldt, Svenja; Boehr, David D

    2014-03-01

    Substrate binding, product release, and likely chemical catalysis in the tryptophan biosynthetic enzyme indole-3-glycerol phosphate synthase (IGPS) are dependent on the structural dynamics of the β1α1 active-site loop. Statistical coupling analysis and molecular dynamic simulations had previously indicated that covarying residues in the β1α1 and β2α2 loops, corresponding to Arg54 and Asn90, respectively, in the Sulfolobus sulfataricus enzyme (ssIGPS), are likely important for coordinating functional motions of these loops. To test this hypothesis, we characterized site mutants at these positions for changes in catalytic function, protein stability and structural dynamics for the thermophilic ssIGPS enzyme. Although there were only modest changes in the overall steady-state kinetic parameters, solvent viscosity and solvent deuterium kinetic isotope effects indicated that these amino acid substitutions change the identity of the rate-determining step across multiple temperatures. Surprisingly, the N90A substitution had a dramatic effect on the general acid/base catalysis of the dehydration step, as indicated by the loss of the descending limb in the pH rate profile, which we had previously assigned to Lys53 on the β1α1 loop. These changes in enzyme function are accompanied with a quenching of ps-ns and µs-ms timescale motions in the β1α1 loop as measured by nuclear magnetic resonance studies. Altogether, our studies provide structural, dynamic and functional rationales for the coevolution of residues on the β1α1 and β2α2 loops, and highlight the multiple roles that the β1α1 loop plays in IGPS catalysis. Thus, substitution of covarying residues in the active-site β1α1 and β2α2 loops of indole-3-glycerol phosphate synthase results in functional, structural, and dynamic changes, highlighting the multiple roles that the β1α1 loop plays in enzyme catalysis and the importance of regulating the structural dynamics of this loop through noncovalent

  18. Numerical multi-loop integrals and applications

    Science.gov (United States)

    Freitas, A.

    2016-09-01

    Higher-order radiative corrections play an important role in precision studies of the electroweak and Higgs sector, as well as for the detailed understanding of large backgrounds to new physics searches. For corrections beyond the one-loop level and involving many independent mass and momentum scales, it is in general not possible to find analytic results, so that one needs to resort to numerical methods instead. This article presents an overview of a variety of numerical loop integration techniques, highlighting their range of applicability, suitability for automatization, and numerical precision and stability. In a second part of this article, the application of numerical loop integration methods in the area of electroweak precision tests is illustrated. Numerical methods were essential for obtaining full two-loop predictions for the most important precision observables within the Standard Model. The theoretical foundations for these corrections will be described in some detail, including aspects of the renormalization, resummation of leading log contributions, and the evaluation of the theory uncertainty from missing higher orders.

  19. Coherent neutrino radiation in supernovae at two loops

    OpenAIRE

    Sedrakian, A.; Dieperink, A. E. L.

    2000-01-01

    We develop a neutrino transport theory, in terms of the real-time non-equilibrium Green's functions, which is applicable to physical conditions arbitrary far from thermal equilibrium. We compute the coherent neutrino radiation in cores of supernovae by evaluating the two-particle-two-hole (2p-2h) polarization function with dressed propagators. The propagator dressing is carried out in the particle-particle channel to all orders in the interaction. We show that at two loops there are two disti...

  20. Heating and cooling of coronal loops observed by SDO

    Science.gov (United States)

    Li, L. P.; Peter, H.; Chen, F.; Zhang, J.

    2015-11-01

    Context. One of the most prominent processes to have been suggested as heating the corona to well above 106 K builds on nanoflares, which are short bursts of energy dissipation. Aims: We compare observations to model predictions to test the validity of the nanoflare process. Methods: Using extreme UV data from AIA/SDO and HMI/SDO line-of-sight magnetograms, we study the spatial and temporal evolution of a set of loops in active region AR 11850. Results: We find a transient brightening of loops in emission from Fe xviii forming at about 7.2 MK, while at the same time these loops dim in emission from lower temperatures. This points to a fast heating of the loop that goes along with evaporation of material that we observe as apparent upward motions in the image sequence. After this initial phase lasting some 10 min, the loops brighten in a sequence of AIA channels that show progressively cooler plasma, indicating that this cooling of the loops lasts about one hour. A comparison to the predictions from a 1D loop model shows that this observation supports the nanoflare process in (almost) all aspects. In addition, our observations show that the loops get broader while getting brighter, which cannot be understood in a 1D model. Movie associated to Fig. 1 is available in electronic form at http://www.aanda.org

  1. Phenomenology of loop quantum cosmology

    CERN Document Server

    Sakellariadou, Mairi

    2010-01-01

    After introducing the basic ingredients of Loop Quantum Cosmology, I will briefly discuss some of its phenomenological aspects. Those can give some useful insight about the full Loop Quantum Gravity theory and provide an answer to some long-standing questions in early universe cosmology.

  2. RCD+: Fast loop modeling server.

    Science.gov (United States)

    López-Blanco, José Ramón; Canosa-Valls, Alejandro Jesús; Li, Yaohang; Chacón, Pablo

    2016-07-08

    Modeling loops is a critical and challenging step in protein modeling and prediction. We have developed a quick online service (http://rcd.chaconlab.org) for ab initio loop modeling combining a coarse-grained conformational search with a full-atom refinement. Our original Random Coordinate Descent (RCD) loop closure algorithm has been greatly improved to enrich the sampling distribution towards near-native conformations. These improvements include a new workflow optimization, MPI-parallelization and fast backbone angle sampling based on neighbor-dependent Ramachandran probability distributions. The server starts by efficiently searching the vast conformational space from only the loop sequence information and the environment atomic coordinates. The generated closed loop models are subsequently ranked using a fast distance-orientation dependent energy filter. Top ranked loops are refined with the Rosetta energy function to obtain accurate all-atom predictions that can be interactively inspected in an user-friendly web interface. Using standard benchmarks, the average root mean squared deviation (RMSD) is 0.8 and 1.4 Å for 8 and 12 residues loops, respectively, in the challenging modeling scenario in where the side chains of the loop environment are fully remodeled. These results are not only very competitive compared to those obtained with public state of the art methods, but also they are obtained ∼10-fold faster. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Improved code-tracking loop

    Science.gov (United States)

    Laflame, D. T.

    1980-01-01

    Delay-locked loop tracks pseudonoise codes without introducing dc timing errors, because it is not sensitive to gain imbalance between signal processing arms. "Early" and "late" reference codes pass in combined form through both arms, and each arm acts on both codes. Circuit accomodates 1 dB weaker input signals with tracking ability equal to that of tau-dither loops.

  4. Loop groups and noncommutative geometry

    CERN Document Server

    Carpi, Sebastiano

    2015-01-01

    We describe the representation theory of loop groups in terms of K-theory and noncommutative geometry. This is done by constructing suitable spectral triples associated with the level l projective unitary positive-energy representations of any given loop group LG. The construction is based on certain supersymmetric conformal field theory models associated with LG.

  5. Brane Couplings from Bulk Loops

    OpenAIRE

    Georgi, Howard; Grant, Aaron K.; Hailu, Girma

    2000-01-01

    We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

  6. Orion Suit Loop Variable Pressure Regulator Development

    Science.gov (United States)

    Mosher, Michael; Vassallo, Andrew; Lewis, John F.; Campbell, Melissa

    2014-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) integrates the cabin and pressure suits with the core life support systems to provide life support during contingency depressurized cabin operations. To provide the multipule suit pressures between nominal pressurized cabin suited operations, suit leak checks, depressurized cabin suited operations, and elevated suit pressure for denitrification, a variable pressure regulator is needed. This paper documents the development and integrated testing of the suit loop regulator for Orion.

  7. Higher dimensional loop quantum cosmology

    Science.gov (United States)

    Zhang, Xiangdong

    2016-07-01

    Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n+1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n+1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n+1 dimensional model and the 3+1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology.

  8. Modeling loop entropy.

    Science.gov (United States)

    Chirikjian, Gregory S

    2011-01-01

    Proteins fold from a highly disordered state into a highly ordered one. Traditionally, the folding problem has been stated as one of predicting "the" tertiary structure from sequential information. However, new evidence suggests that the ensemble of unfolded forms may not be as disordered as once believed, and that the native form of many proteins may not be described by a single conformation, but rather an ensemble of its own. Quantifying the relative disorder in the folded and unfolded ensembles as an entropy difference may therefore shed light on the folding process. One issue that clouds discussions of "entropy" is that many different kinds of entropy can be defined: entropy associated with overall translational and rotational Brownian motion, configurational entropy, vibrational entropy, conformational entropy computed in internal or Cartesian coordinates (which can even be different from each other), conformational entropy computed on a lattice, each of the above with different solvation and solvent models, thermodynamic entropy measured experimentally, etc. The focus of this work is the conformational entropy of coil/loop regions in proteins. New mathematical modeling tools for the approximation of changes in conformational entropy during transition from unfolded to folded ensembles are introduced. In particular, models for computing lower and upper bounds on entropy for polymer models of polypeptide coils both with and without end constraints are presented. The methods reviewed here include kinematics (the mathematics of rigid-body motions), classical statistical mechanics, and information theory.

  9. The loop gravity string

    CERN Document Server

    Freidel, Laurent; Pranzetti, Daniele

    2016-01-01

    In this work we study canonical gravity in finite regions for which we introduce a generalisation of the Gibbons-Hawking boundary term including the Immirzi parameter. We study the canonical formulation on a spacelike hypersuface with a boundary sphere and show how the presence of this term leads to an unprecedented type of degrees of freedom coming from the restoration of the gauge and diffeomorphism symmetry at the boundary. In the presence of a loop quantum gravity state, these boundary degrees of freedom localize along a set of punctures on the boundary sphere. We demonstrate that these degrees of freedom are effectively described by auxiliary strings with a 3-dimensional internal target space attached to each puncture. We show that the string currents represent the local frame field, that the string angular momenta represent the area flux and that the string stress tensor represents the two dimensional metric on the boundary of the region of interest. Finally, we show that the commutators of these broken...

  10. Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines

    Data.gov (United States)

    National Aeronautics and Space Administration — Software-in-the-loop and hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and...

  11. Hard Loops, Soft Loops, and High Density Effective Field Theory

    CERN Document Server

    Schäfer, T

    2003-01-01

    We study several issues related to the use of effective field theories in QCD at large baryon density. We show that the power counting is complicated by the appearance of two scales inside loop integrals. Hard dense loops involve the large scale $mu^2$ and lead to phenomena such as screening and damping at the scale $gmu$. Soft loops only involve small scales and lead to superfluidity and non-Fermi liquid behavior at exponentially small scales. Four-fermion operators in the effective theory are suppressed by powers of $1/mu$, but they get enhanced by hard loops. As a consequence their contribution to the pairing gap is only suppressed by powers of the coupling constant, and not powers of $1/mu$. We determine the coefficients of four-fermion operators in the effective theory by matching quark-quark scattering amplitudes. Finally, we introduce a perturbative scheme for computing corrections to the gap parameter in the superfluid phase

  12. Radial propagators and Wilson loops

    CERN Document Server

    Leupold, S; Leupold, Stefan; Weigert, Heribert

    1996-01-01

    We present a relation which connects the propagator in the radial (Fock-Schwinger) gauge with a gauge invariant Wilson loop. It is closely related to the well-known field strength formula and can be used to calculate the radial gauge propagator. The result is shown to diverge in four-dimensional space even for free fields, its singular nature is however naturally explained using the renormalization properties of Wilson loops with cusps and self-intersections. Using this observation we provide a consistent regularization scheme to facilitate loop calculations. Finally we compare our results with previous approaches to derive a propagator in Fock-Schwinger gauge.

  13. Precision Holography with Supersymmetric Wilson Loops

    CERN Document Server

    Faraggi, Alberto; Silva, Guillermo A; Trancanelli, Diego

    2016-01-01

    We consider certain 1/4 BPS Wilson loop operators in $SU(N)$ ${\\cal N}=4$ super Yang-Mills theory, whose expectation value can be computed exactly via supersymmetric localization. Holographically, these operators are mapped to fundamental strings in $AdS_5\\times S^5$. The string on-shell action reproduces the large $N$ and large coupling limit of the gauge theory expectation value and, according to the AdS/CFT correspondence, there should also be a precise match between subleading corrections to these limits. We perform a test of such match at next-to-leading order in string theory, by computing the 1-loop determinant of the quantum fluctuations around the classical string configuration. A source of ambiguity, related to ghost zero modes, is removed by comparing our operator with the 1/2 BPS circular Wilson loop. We find perfect agreement between the string theory result and the gauge theory prediction. This successful match, besides being a high precision test of the AdS/CFT correspondence, elucidates some o...

  14. Blind loop syndrome: an unusual cause of panniculitis.

    Science.gov (United States)

    Caux, F; Halimi, C; Kevorkian, J P; Pinquier, L; Dubertret, L; Segrestaa, J M

    1997-11-01

    We describe a 52-year-old woman with panniculitis and blind loop syndrome. She had undergone a gastrectomy for peptic ulcer 4 years before. Tender erythematous nodules on her palms and soles were associated with diarrhea and weight loss. A biopsy specimen revealed septal and lobular panniculitis. A glucose hydrogen breath test was consistent with bacterial overgrowth. These results were consistent with panniculitis associated with a blind loop syndrome. Only four cases of this association have been reported previously.

  15. Numerical approach to multi-loop integrals

    CERN Document Server

    Kato, K; Hamaguchi, N; Ishikawa, T; Koike, T; Kurihara, Y; Shimizu, Y; Yuasa, F

    2012-01-01

    For the calculation of multi-loop Feynman integrals, a novel numerical method, the Direct Computation Method (DCM) is developed. It is a combination of a numerical integration and a series extrapolation. In principle, DCM can handle diagrams of arbitrary internal masses and external momenta, and can calculate integrals with general numerator function. As an example of the performance of DCM, a numerical computation of two-loop box diagrams is presented. Further discussion is given on the choice of control parameters in DCM. This method will be an indispensable tool for the higher order radiative correction when it is tested for a wider class of physical parameters and the separation of divergence is done automatically.

  16. Two novel automatic frequency tracking loops

    Science.gov (United States)

    Aguirre, Sergio; Hinedi, Sami

    1989-01-01

    Two automatic-frequency-control (AFC) loops are introduced and analyzed in detail. The algorithms are generalizations of the well known cross-product AFC loop with improved performance. The first estimator uses running overlapping discrete Fourier transforms to create a discriminator curve proportional to the frequency estimation error, whereas the second one preprocesses the received data and then uses an extended Kalman filter to estimate the input frequency. The algorithms are tested by computer simulations in a highly dynamic environment at low carrier/noise ratio (CNR). The algorithms are suboptimum tracking schemes with a larger frequency-error variance compared to an optimum strategy, but they offer simplicity of mechanization and a CNR with a very low operating threshold.

  17. Hardware-in-the-loop test bench research of hybrid energy storage systems in electric vehicles%纯电动汽车车载电源性能在环测试平台研究

    Institute of Scientific and Technical Information of China (English)

    李勇; Mehrdad Kazerani; 马飞

    2014-01-01

    为研究纯电动汽车车载电源性能,提出并搭建了由异步电动机和直流电动机组成的在环测试平台。异步电动机用来模拟纯电动汽车的牵引电动机,直流电动机用来模拟汽车行驶时的阻力和惯量,对异步电动机和直流电动机分别实施转速控制和转矩控制。分析了电动汽车行驶工况,给出了简单循环工况下参考转速、转距和功率。设计了异步电动机调速系统转速控制器和电流控制器,建立了异步电动机调速系统的数学模型,提出了基于自适应模糊神经网络控制的异步电动机调速系统。仿真和实验结果表明,基于自适应模糊神经网络控制的调速系统明显优于PID控制的交流调速系统,在环测试平台能够较好跟踪参考转速和参考转距的变化。%Hybrid energy storage systems (HESS) play an important role in electric vehicles. This paper mainly focuses on a hardware-in-the-loop (HIL) test bench for testing the performance of HESS. The scenario of an induction motor and a DC motor was proposed. The induction motor was used as a traction motor while the DC motor worked as the load and moment of inertia of the vehicle. Speed control was implemented on the induction motor while torque control was applied to the DC motor. The speed, torque and power of the traction motor were obtained from a simple drive cycle based on real parameters. The motor speed was given as a reference of the induction motor while the load torque was used as a reference of the DC motor. The speed control system of the induction motor and the torque control of the DC motor were analyzed and designed. Meanwhile, the speed control system of the induction motor was modeled. Adaptive fuzzy neural-network control was proposed to achieve high accuracy due to the low accuracy of PID control. Simulation and experimental results agreed with the proposal. The test bench follows the reference speed and reference torque

  18. Sequence dependence of transcription factor-mediated DNA looping.

    Science.gov (United States)

    Johnson, Stephanie; Lindén, Martin; Phillips, Rob

    2012-09-01

    DNA is subject to large deformations in a wide range of biological processes. Two key examples illustrate how such deformations influence the readout of the genetic information: the sequestering of eukaryotic genes by nucleosomes and DNA looping in transcriptional regulation in both prokaryotes and eukaryotes. These kinds of regulatory problems are now becoming amenable to systematic quantitative dissection with a powerful dialogue between theory and experiment. Here, we use a single-molecule experiment in conjunction with a statistical mechanical model to test quantitative predictions for the behavior of DNA looping at short length scales and to determine how DNA sequence affects looping at these lengths. We calculate and measure how such looping depends upon four key biological parameters: the strength of the transcription factor binding sites, the concentration of the transcription factor, and the length and sequence of the DNA loop. Our studies lead to the surprising insight that sequences that are thought to be especially favorable for nucleosome formation because of high flexibility lead to no systematically detectable effect of sequence on looping, and begin to provide a picture of the distinctions between the short length scale mechanics of nucleosome formation and looping.

  19. Product Integrals and Wilson loops

    CERN Document Server

    Karp, R L

    2001-01-01

    Using product integrals we review the unambiguous mathematical representation of Wilson line and Wilson loop operators, including their behavior under gauge transformations and the non-abelian Stokes theorem. Interesting consistency conditions among Wilson lines are also presented.

  20. Thermal fluctuations in loop cosmology

    CERN Document Server

    Magueijo, J; Magueijo, Joao; Singh, Parampreet

    2007-01-01

    Quantum gravitational effects in loop quantum cosmology lead to a resolution of the initial singularity and have the potential to solve the horizon problem and generate a quasi scale-invariant spectrum of density fluctuations. We consider loop modifications to the behavior of the inverse scale factor below a critical scale in closed models and assume a purely thermal origin for the fluctuations. We show that the no-go results for scale invariance in classical thermal models can be evaded even if we just consider modifications to the background (zeroth order) gravitational dynamics. Since a complete and systematic treatment of the perturbed Einstein equations in loop cosmology is still lacking, we simply parameterize their expected modifications. These change quantitatively, but not qualitatively, our conclusions. We thus urge the community to more fully work out this complex aspect of loop cosmology, since the full picture would not only fix the free parameters of the theory, but also provide a model for a no...

  1. Loop Quantum Cosmology Gravitational Baryogenesis

    CERN Document Server

    Odintsov, S D

    2016-01-01

    Loop Quantum Cosmology is an appealing quantum completion of classical cosmology, which brings along various theoretical features which in many cases offer remedy or modify various classical cosmology aspects. In this paper we address the gravitational baryogenesis mechanism in the context of Loop Quantum Cosmology. As we demonstrate, when Loop Quantum Cosmology effects are taken into account in the resulting Friedmann equations for a flat Friedmann-Robertson-Walker Universe, then even for a radiation dominated Universe, the predicted baryon-to-entropy ratio from the gravitational baryogenesis mechanism is non-zero, in contrast to the Einstein-Hilbert case, in which case the baryon-to-entropy ratio is zero. We also discuss various other cases apart from the radiation domination case, and we discuss how the baryon-to-entropy ratio is affected from the parameters of the quantum theory. In addition, we use illustrative exact solutions of Loop Quantum Cosmology and we investigate under which circumstances the bar...

  2. Continuous smearing of Wilson Loops

    CERN Document Server

    Lohmayer, Robert

    2011-01-01

    Continuum smearing was introduced in section 4.1 of JHEP03, 064 (2006) as a meaningful continuum analogue of the well known set of lattice techniques by the same name. Here we apply continuous smearing in continuous space-time to Wilson loops in order to clarify what it does in the context of field theory and also in the context of the loop calculus of the Makeenko-Migdal equation.

  3. The Projectile inside the Loop

    OpenAIRE

    Varieschi, Gabriele U.

    2005-01-01

    In this paper we describe an alternative use of the loop-the-loop apparatus, which can be used to study an interesting case of projectile motion. We also present an effective way to perform and analyze these experiments, by using video capture software together with a digital video camera. These experiments can be integrated into classroom demonstrations for general physics courses, or become part of laboratory activities.

  4. Introduction to Loop Quantum Gravity

    OpenAIRE

    Mercuri, Simone

    2010-01-01

    The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a description of some general arguments and an introduction to the canonical theory of gravity, I review the background independent approach to quantum gravity, giving only a brief survey of Loop Quantum Gravity.

  5. Bifurcations of nontwisted heteroclinic loop

    Institute of Scientific and Technical Information of China (English)

    田清平; 朱德明

    2000-01-01

    Bifurcations of nontwisted and fine heteroclinic loops are studied for higher dimensional systems. The existence and its associated existing regions are given for the 1-hom orbit and the 1-per orbit, respectively, and bifurcation surfaces of the two-fold periodic orbit are also obtained. At last, these bifurcation results are applied to the fine heteroclinic loop for the planar system, which leads to some new and interesting results.

  6. Spacecraft Thermal Management using Advanced Hybrid Two-Phase Loop Technology

    Science.gov (United States)

    2007-02-01

    HYBRID TWO-PHASE LOOPS The schematic of the Hybrid Two-Phase Loop (HTPL) used for a thermal testing is shown in Figure 3. Main components for the...hybrid two-phase loop with single evaporator. The thermal test starts first by turning on the liquid pump to circulate liquid along the loop. Once the...Vapor Out Evaporator Body (E1) Evaporator Body (E2) Total Heat Input Heat Input (E1) Heat Input (E2) Thermal Resistance (E1) FIGURE 10. Thermal test results

  7. Mono Lake Excursion in Cored Sediment from the Eastern Tyrrhenian Sea

    Science.gov (United States)

    Liddicoat, Joseph; Iorio, Marina; Sagnotti, Leonardo; Incoronato, Alberto

    2013-04-01

    A search for the Laschamp and Mono Lake excursions in cored marine and lacustrine sediment younger than 50,000 years resulted in the discovery of both excursions in the Greenland Sea (73.3˚ N, 351.0˚ E, Nowaczyk and Antanow, 1997), in the North Atlantic Ocean (62.7˚ N, 222.5˚ E, Channell, 2006), in Pyramid Lake in the Lahontan Basin, NV, USA (40.1˚ N, 240.2˚ E, Benson et al., 2008), and in the Black Sea (43.2˚ N, 36.5˚ E, Nowaczyk et al., 2012). The inclination, declination, and relative field intensity during the Mono Lake Excursion (MLE) in the Black Sea sediment matches well the behaviour of the excursion in the Mono Basin, CA, in that a reduction in inclination during westerly declination is soon followed by steep positive inclination when declination is easterly, and relative field intensity increases after a low at the commencement of the excursion (Liddicoat and Coe, 1979). A large clockwise loop of Virtual Geomagnetic Poles (VGPs) at the Black Sea when followed from old to young patterns very well the VGP loop formed by the older portion of the MLE in the Mono Basin (Liddicoat and Coe, 1979). We also searched for the MLE in cored sediment from the eastern Tyrrhenian Sea (40.1˚ N, 14.7˚ E) where the age of the sediment is believed to be about 32,000 years when comparing the susceptibility in the core with the susceptibility in a nearby one that is dated by palaeomagnetic secular variation records, Carbon-14, and numerous tephra layers in the Tyrrhenian Sea sediment (Iorio et al., 2011). In the Tyrrhenian Sea core, called C1067, closely spaced samples demagnetized in an alternating field to100 mT record a shallowing of positive inclination to 48˚ that is followed by steep positive inclination of 82˚ when declination moves rapidly to the southeast. The old to young path of the VGPs in C1067 forms a narrow counter-clockwise loop that reaches 30.3˚ N, 30.8˚ E and that is centered at about 55˚ N, 15˚ E. Although descending to a latitude that is

  8. Dimensional assessment of continuous loop cortical suspension devices and clinical implications for intraoperative button flipping and intratunnel graft length.

    Science.gov (United States)

    Turnbull, Travis Lee; LaPrade, Christopher M; Smith, Sean D; LaPrade, Robert F; Wijdicks, Coen A

    2015-09-01

    Continuous loop cortical suspension devices have been demonstrated to be more consistent and biomechanically superior compared to adjustable loop devices; however, continuous loop devices present unique challenges compared to adjustable loop devices, especially in short tunnel reconstruction applications. Specifically, adjustable loop devices have the advantage of a "one size fits all" approach, and the ability to tension these devices following button flipping allows for the intratunnel graft length to be maximized. Nevertheless, the reliability of continuous loop devices has sustained their widespread use. We hypothesized that continuous loop cortical suspension devices from different manufacturers would exhibit equivalent 15 mm loop lengths, as advertised. Loop length was measured using a tensile testing machine. Contrary to our hypothesis, continuous loop cortical suspension devices with equivalent advertised lengths exhibited different loop lengths (up to 27% discrepancy). Inconsistencies with regards to manufacturers' reported loop lengths for continuous loop devices could have serious clinical implications and additionally complicate technique transferal among devices. Consequently, the manufacturers' accurate and complete disclosure of the dimensions and specifications associated with each continuous loop device is critical. Furthermore, surgeon awareness of true loop length dimensions and inconsistencies among devices is needed to ensure optimal implantation and resultant clinical outcomes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. DNA looping by FokI: the impact of twisting and bending rigidity on protein-induced looping dynamics

    Science.gov (United States)

    Laurens, Niels; Rusling, David A.; Pernstich, Christian; Brouwer, Ineke; Halford, Stephen E.; Wuite, Gijs J. L.

    2012-01-01

    Protein-induced DNA looping is crucial for many genetic processes such as transcription, gene regulation and DNA replication. Here, we use tethered-particle motion to examine the impact of DNA bending and twisting rigidity on loop capture and release, using the restriction endonuclease FokI as a test system. To cleave DNA efficiently, FokI bridges two copies of an asymmetric sequence, invariably aligning the sites in parallel. On account of the fixed alignment, the topology of the DNA loop is set by the orientation of the sites along the DNA. We show that both the separation of the FokI sites and their orientation, altering, respectively, the twisting and the bending of the DNA needed to juxtapose the sites, have profound effects on the dynamics of the looping interaction. Surprisingly, the presence of a nick within the loop does not affect the observed rigidity of the DNA. In contrast, the introduction of a 4-nt gap fully relaxes all of the torque present in the system but does not necessarily enhance loop stability. FokI therefore employs torque to stabilise its DNA-looping interaction by acting as a ‘torsional’ catch bond. PMID:22373924

  10. Mechanical evaluation of space closure loops in Orthodontics

    Directory of Open Access Journals (Sweden)

    Eduardo Uggeri Rodrigues

    2011-02-01

    Full Text Available This study evaluated the mechanical performance of teardrop-shaped loops and teardrop-shaped loops with helix used in orthodontic space closure. Sixty retraction loops made with 0.019" x 0.025" stainless steel (SS and beta-titanium (BT wires were used. They were attached to a testing machine to measure the magnitudes of the sagittal force and the load-deflection ratio necessary for 1 mm, 2 mm and 3 mm activation. The results demonstrated that the BT alloy presented significantly smaller mean values (p < 0.01 of sagittal force and load-deflection than the SS alloy. The loop with the highest mean value of sagittal force and load-deflection was the teardrop-shaped loop (p < 0.01. Differences were observed in the mean values of sagittal force and load-deflection among activations, and the highest mean value was found in the activation of 3 mm, while the smallest mean value was evident in the activation of 1 mm (p < 0.01. It could be concluded that the metallic alloy used and the presence of a helix in configuration of the loops may have a strong influence on the sagittal force produced and on the load-deflection ratio; the teardrop-shaped loops and teardrop-shaped loops with helix in BT presented the release of lighter forces; the teardrop-shaped loop in SS generated a high load-deflection ratio, providing high magnitudes of horizontal force during its deactivation.

  11. Toward precision holography with supersymmetric Wilson loops

    Science.gov (United States)

    Faraggi, Alberto; Pando Zayas, Leopoldo A.; Silva, Guillermo A.; Trancanelli, Diego

    2016-04-01

    We consider certain 1/4 BPS Wilson loop operators in SU( N) N=4 supersymmetric Yang-Mills theory, whose expectation value can be computed exactly via supersymmetric localization. Holographically, these operators are mapped to fundamental strings in AdS 5 × S 5. The string on-shell action reproduces the large N and large coupling limit of the gauge theory expectation value and, according to the AdS/CFT correspondence, there should also be a precise match between subleading corrections to these limits. We perform a test of such match at next-to-leading order in string theory, by deriving the spectrum of quantum fluctuations around the classical string solution and by computing the corresponding 1-loop effective action. We discuss in detail the supermultiplet structure of the fluctuations. To remove a possible source of ambiguity in the ghost zero mode measure, we compare the 1/4 BPS configuration with the 1/2 BPS one, dual to a circular Wilson loop. We find a discrepancy between the string theory result and the gauge theory prediction, confirming a previous result in the literature. We are able to track the modes from which this discrepancy originates, as well as the modes that by themselves would give the expected result.

  12. Gubernaculum with a long loop vas deferens

    Directory of Open Access Journals (Sweden)

    Cesim Irsi

    2016-04-01

    Full Text Available Cryptorchidism by definition suggests a hidden testis: a testis that is not within the scrotum and does not descend spontaneously into the scrotum by six months of age. Cryptorchid testes may be absent or undescended. If they haven't descended by six months of age, they are unlikely to descend and generally require surgical manipulation into and attachment to the scrotum to avoid potential complications and sequelaes. This case describes an anatomical variation of vas deferens with gubernaculum which not previously reported in literature. A 9 month old boy was presented with diagnosis of left undescended testis and underwent standard orchiopexy operation. At the time of gubernacular dissection a long loop vas deferens without epididymis abnormalities was observed. A long loop of vas deferens originated from tail of epididymis and rotated up then formed a long loop with in the gubernaculum. This case reminds us of the possibility of anatomical variations and the importance of keeping them in mind to prevent complications at time of surgery.

  13. Corrosion of alloy 718 in a mercury thermal convection loop

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, S.J.; DiStefano, J.R.; Manneschmidt, E.T.

    1999-12-01

    Two thermal convection loops (TCLs) fabricated from annealed alloy 718 continuously circulated mercury (Hg) with 1000 wppm gallium (Ga), respectively, for about 5000 h, duplicating previous TCL tests for annealed 316L. In each case, the maximum loop temperature was 305C, the minimum temperature was 242C, and the Hg flow rate was approximately 1.2 m/min. Unlike the 316L exposed to Hg, which above about 260C exhibited a thin, porous surface layer depleted in Ni and Cr, the alloy 718 coupons revealed essentially no wetting and, therefore, no interaction with that Hg at any temperature. Alloy 718 coupons suspended in the loops revealed inconsequentially small weight changes, and both the coupons and loop tubing exhibited no detectable metallographic evidence of attack.

  14. Polarisation of microwave emission from reconnecting twisted coronal loops

    CERN Document Server

    Gordovskyy, Mykola; Kontar, Eduard

    2016-01-01

    Magnetic reconnection and particle acceleration due to the kink instability in twisted coronal loops can be a viable scenario for confined solar flares. Detailed investigation of this phenomenon requires reliable methods for observational detection of magnetic twist in solar flares, which may not be possible solely through extreme UV and soft X-ray thermal emission. The gradient of microwave polarisation across flaring loops can serve as one of the detection criteria. The aim of this study is to investigate the effect of magnetic twist in flaring coronal loops on the polarisation of gyro-synchrotron microwave emission, and determine whether microwave emission polarisation could provide a means for observational detection. We use time-dependent magnetohydrodynamic and test-particle models, developed using LARE3D and GCA codes to investigate twisted coronal loops relaxing following the kink-instability, and calculate synthetic microwave emission maps (I and V Stokes components) using GX simulator. It is found t...

  15. Dosimetry Evaluation of In-Core and Above-Core Zirconium Alloy Samples in a PWR

    Directory of Open Access Journals (Sweden)

    Amiri Benjamin W.

    2016-01-01

    Full Text Available A description of the neutron fluence analysis of activated zirconium alloys samples at a Westinghouse 3-loop reactor is presented. These samples were irradiated in the core and in the fuel plenum region, where dosimetry measurements are relatively rare compared with regions radially outward of the core. Dosimetry measurements performed by Batelle/PNNL are compared to the calculational models. Good agreement is shown with the in-core measurements when using analysis conditions expected to best represent this region, such as an assembly-specific axial power distribution. However, the use of these conditions to evaluate dosimetry in the fuel plenum region can lead to significant underestimation of the fluence. The use of a flat axial power distribution, however, does not underestimate the fluence in the fuel plenum region.

  16. A detailed BWR recirculation loop model for RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Araiza-Martínez, Enrique, E-mail: enrique.araiza@inin.gob.mx; Ortiz-Villafuerte, Javier, E-mail: javier.ortiz@inin.gob.mx; Castillo-Durán, Rogelio, E-mail: rogelio.castillo@inin.gob.mx

    2017-01-15

    Highlights: • A new detailed BWR recirculation loop model was developed for RELAP. • All jet pumps, risers, manifold, suction and control valves, and recirculation pump are modeled. • Model is tested against data from partial blockage of two jet pumps. • For practical applications, simulation results showed good agreement with available data. - Abstract: A new detailed geometric model of the whole recirculation loop of a BWR has been developed for the code RELAP. This detailed model includes the 10 jet pumps, 5 risers, manifold, suction and control valves, and the recirculation pump, per recirculation loop. The model is tested against data from an event of partial blockage at the entrance nozzle of one jet pump in both recirculation loops. For practical applications, simulation results showed good agreement with data. Then, values of parameters considered as figure of merit (reactor power, dome pressure, core flow, among others) for this event are compared against those from the common 1 jet pump per loop model. The results show that new detailed model led to a closer prediction of the reported power change. The detailed recirculation loop model can provide more reliable boundary condition data to a CFD models for studies of, for example, flow induced vibration, wear, and crack initiation.

  17. Bol loops of odd prime exponent

    CERN Document Server

    Foguel, Tuval

    2009-01-01

    Although any finite Bol loop of odd prime exponent is solvable, we show there exist such Bol loops with trivial center. We also construct finitely generated, infinite, simple Bruck loops of odd prime exponent for sufficiently large primes. This shows that the Burnside problem for Bruck loops has a negative answer.

  18. Classifying Finitely Generated Indecomposable RA Loops

    CERN Document Server

    Cornelissen, Mariana

    2012-01-01

    In 1995, E. Jespers, G. Leal and C. Polcino Milies classified all finite ring alternative loops (RA loops for short) which are not direct products of proper subloops. In this paper we extend this result to finitely generated RA loops and provide an explicit description of all such loops.

  19. Kalman Orbit Optimized Loop Tracking

    Science.gov (United States)

    Young, Lawrence E.; Meehan, Thomas K.

    2011-01-01

    Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

  20. Swarm intelligence of artificial bees applied to In-Core Fuel Management Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Oliveira, Iona Maghali, E-mail: ioliveira@con.ufrj.br [Nuclear Engineering Program, Federal University of Rio de Janeiro, P.O. Box 68509, Zip Code 21945-970, Rio de Janeiro, RJ (Brazil); Schirru, Roberto, E-mail: schirru@lmp.ufrj.br [Nuclear Engineering Program, Federal University of Rio de Janeiro, P.O. Box 68509, Zip Code 21945-970, Rio de Janeiro, RJ (Brazil)

    2011-05-15

    Research highlights: > We present Artificial Bee Colony with Random Keys (ABCRK) for In-Core Fuel Management Optimization. > Its performance is examined through the optimization of a Brazilian '2-loop' PWR. > Feasibility of using ABCRK is shown against some well known population-based algorithms. > Additional advantage includes the utilization of fewer control parameters. - Abstract: Artificial Bee Colony (ABC) algorithm is a relatively new member of swarm intelligence. ABC tries to simulate the intelligent behavior of real honey bees in food foraging and can be used for solving continuous optimization and multi-dimensional numeric problems. This paper introduces the Artificial Bee Colony with Random Keys (ABCRK), a modified ABC algorithm for solving combinatorial problems such as the In-Core Fuel Management Optimization (ICFMO). The ICFMO is a hard combinatorial optimization problem in Nuclear Engineering which during many years has been solved by expert knowledge. It aims at getting the best arrangement of fuel in the nuclear reactor core that leads to a maximization of the operating time. As a consequence, the operation cost decreases and money is saved. In this study, ABCRK is used for optimizing the ICFMO problem of a Brazilian '2-loop' Pressurized Water Reactor (PWR) Nuclear Power Plant (NPP) and the results obtained with the proposed algorithm are compared with those obtained by Genetic Algorithms (GA) and Particle Swarm Optimization (PSO). The results show that the performance of the ABCRK algorithm is better than or similar to that of other population-based algorithms, with the advantage of employing fewer control parameters.

  1. Study of the Open Loop and Closed Loop Oscillator Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Imel, George R. [Idaho State Univ., Pocatello, ID (United States); Baker, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Riley, Tony [Knolls Atomic Power Lab. (KAPL), Schenectady, NY (United States); Langbehn, Adam [Puget Sound Naval Base, Bremerton, WA (United States); Aryal, Harishchandra [Idaho State Univ., Pocatello, ID (United States); Benzerga, M. Lamine [Idaho State Univ., Pocatello, ID (United States)

    2015-04-11

    This report presents the progress and completion of a five-year study undertaken at Idaho State University of the measurement of very small worth reactivity samples comparing open and closed loop oscillator techniques.The study conclusively demonstrated the equivalency of the two techniques with regard to uncertainties in reactivity values, i.e., limited by reactor noise. As those results are thoroughly documented in recent publications, in this report we will concentrate on the support work that was necessary. For example, we describe in some detail the construction and calibration of a pilot rod for the closed loop system. We discuss the campaign to measure the required reactor parameters necessary for inverse-kinetics. Finally, we briefly discuss the transfer of the open loop technique to other reactor systems.

  2. BPS Wilson Loops on S^2 at Higher Loops

    CERN Document Server

    Young, Donovan

    2008-01-01

    We consider supersymmetric Wilson loops of the variety constructed by Drukker, Giombi, Ricci, and Trancanelli, whose spatial contours lie on a two-sphere. Working to second order in the 't Hooft coupling in planar N=4 Supersymmetric Yang-Mills Theory (SYM), we compute the vacuum expectation value of a wavy-latitude and of a loop composed of two longitudes. We evaluate the resulting integrals numerically and find that the results are consistent with the zero-instanton sector calculation of Wilson loops in 2-d Yang-Mills on S^2 performed by Bassetto and Griguolo. We also consider the connected correlator of two distinct latitudes to third order in the 't Hooft coupling in planar N=4 SYM. We compare the result in the limit where the latitudes become coincident to a perturbative calculation in 2-d Yang-Mills on S^2 using a light-cone Wu-Mandelstam-Leibbrandt prescription. The two calculations produce differing results.

  3. Generalized loop space and TMDs

    Directory of Open Access Journals (Sweden)

    Mertens Tom

    2014-06-01

    Full Text Available The Standard Model describes the three (of four basic interactions known in Nature in terms of the quantum fields which are constituted by representations of special unitary gauge groups of symmetry. However, the physical observables do not always coincide with the fundamental degrees of freedom of the Standard Model. Therefore it can be useful to switch to the loop space representation of the gauge theory, where the variables are inherently gauge invariant but the degrees of freedom are absorbed in the path/loop dependence. Over-completeness of this space requires the introduction of an equivalence relation which is provided by Wilson loop functionals operating on piecewise regular paths. It is well known that certain Wilson loops show the same singularity structure as some Transverse Momentum Dependent PDFs (TMDs, which are not renormalizable by the common methods due to exactly this singularity structure. By introducing geometrical operators, like the area-derivative, we were able to derive an evolution equation for these Wilson loops and we hope to apply this method in the future to find some renormalization schemes for TMDs.

  4. Loop coupled resonator optical waveguides.

    Science.gov (United States)

    Song, Junfeng; Luo, Lian-Wee; Luo, Xianshu; Zhou, Haifeng; Tu, Xiaoguang; Jia, Lianxi; Fang, Qing; Lo, Guo-Qiang

    2014-10-06

    We propose a novel coupled resonator optical waveguide (CROW) structure that is made up of a waveguide loop. We theoretically investigate the forbidden band and conduction band conditions in an infinite periodic lattice. We also discuss the reflection- and transmission- spectra, group delay in finite periodic structures. Light has a larger group delay at the band edge in a periodic structure. The flat band pass filter and flat-top group delay can be realized in a non-periodic structure. Scattering matrix method is used to calculate the effects of waveguide loss on the optical characteristics of these structures. We also introduce a tunable coupling loop waveguide to compensate for the fabrication variations since the coupling coefficient of the directional coupler in the loop waveguide is a critical factor in determining the characteristics of a loop CROW. The loop CROW structure is suitable for a wide range of applications such as band pass filters, high Q microcavity, and optical buffers and so on.

  5. Vertically Polarized Omnidirectional Printed Slot Loop AntennaPrinted Slot Loop Antenna (invited)

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren Helstrup; Thaysen, Jesper

    2015-01-01

    A novel verticall A novel vertically polarized dpolarize , omnidirection omnidirectional l , printed slot loop antenna h sprinted slot loop antenna has been designed, simulated, fabricated, and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform...

  6. Brief review on black hole loop quantization

    CERN Document Server

    Olmedo, Javier

    2016-01-01

    Here we present a review about the quantization of spherically symmetric spacetimes adopting loop quantum gravity techniques. Several models that have been studied so far share similar properties: the resolution of the classical singularity, and some of them an intrinsic discretization of the geometry. We also explain the extension to Reissner-Nordstr\\"om black holes. Besides, we review how quantum test fields on these quantum geometries allow us to study phenomena like the Casimir effect or Hawking radiation. Finally, we briefly describe a recent proposal that incorporates spherically symmetric matter, discussing its relevance for the understanding of black hole evolution.

  7. Mercury Thermal Hydraulic Loop (MTHL) Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Felde, David K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Crye, Jason Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wendel, Mark W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Farquharson, George [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jallouk, Philip A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McFee, Marshall T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pointer, William David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruggles, Art E. [Univ. of Tennessee, Knoxville, TN (United States); Carbajo, Juan J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The Spallation Neutron Source (SNS) is a high-power linear accelerator built at Oak Ridge National Laboratory (ORNL) which incorporates the use of a flowing liquid mercury target. The Mercury Thermal Hydraulic Loop (MTHL) was constructed to investigate and verify the heat transfer characteristics of liquid mercury in a rectangular channel. This report provides a compilation of previously reported results from the water-cooled and electrically heated straight and curved test sections that simulate the geometry of the window cooling channel in the target nose region.

  8. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  9. Loop quantum cosmology: Recent progress

    Indian Academy of Sciences (India)

    Martin Bojowald

    2004-10-01

    Aspects of the full theory of loop quantum gravity can be studied in a simpler context by reducing to symmetric models like cosmological ones. This leads to several applications where loop effects play a significant role when one is sensitive to the quantum regime. As a consequence, the structure of and the approach to classical singularities are very different from general relativity. The quantum theory is free of singularities, and there are new phenomenological scenarios for the evolution of the very early universe such as inflation. We give an overview of the main effects, focussing on recent results obtained by different groups.

  10. Loop quantum geometry: a primer

    Energy Technology Data Exchange (ETDEWEB)

    Corichi, Alejandro [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A. Postal 70-543, Mexico D.F. 04510 (Mexico)

    2005-01-15

    This is the written version of a lecture given at the 'VI Mexican School of Gravitation and Mathematical Physics' (Nov 21-27, 2004, Playa del Carmen, Mexico), introducing the basics of Loop Quantum Geometry. The purpose of the written contribution is to provide a Primer version, that is, a first entry into Loop Quantum Gravity and to present at the same time a friendly guide to the existing pedagogical literature on the subject. This account is geared towards graduate students and non-experts interested in learning the basics of the subject.

  11. Loop Quantum Geometry: A primer

    OpenAIRE

    Corichi, Alejandro

    2005-01-01

    This is the written version of a lecture given at the ``VI Mexican School of Gravitation and Mathematical Physics" (Nov 21-27, 2004, Playa del Carmen, Mexico), introducing the basics of Loop Quantum Geometry. The purpose of the written contribution is to provide a Primer version, that is, a first entry into Loop Quantum Gravity and to present at the same time a friendly guide to the existing pedagogical literature on the subject. This account is geared towards graduate students and non-expert...

  12. Virtual grasping: closed-loop force control using electrotactile feedback.

    Science.gov (United States)

    Jorgovanovic, Nikola; Dosen, Strahinja; Djozic, Damir J; Krajoski, Goran; Farina, Dario

    2014-01-01

    Closing the control loop by providing somatosensory feedback to the user of a prosthesis is a well-known, long standing challenge in the field of prosthetics. Various approaches have been investigated for feedback restoration, ranging from direct neural stimulation to noninvasive sensory substitution methods. Although there are many studies presenting closed-loop systems, only a few of them objectively evaluated the closed-loop performance, mostly using vibrotactile stimulation. Importantly, the conclusions about the utility of the feedback were partly contradictory. The goal of the current study was to systematically investigate the capability of human subjects to control grasping force in closed loop using electrotactile feedback. We have developed a realistic experimental setup for virtual grasping, which operated in real time, included a set of real life objects, as well as a graphical and dynamical model of the prosthesis. We have used the setup to test 10 healthy, able bodied subjects to investigate the role of training, feedback and feedforward control, robustness of the closed loop, and the ability of the human subjects to generalize the control to previously "unseen" objects. Overall, the outcomes of this study are very optimistic with regard to the benefits of feedback and reveal various, practically relevant, aspects of closed-loop control.

  13. Ponderomotive Acceleration in Coronal Loops

    Science.gov (United States)

    Dahlburg, R. B.; Laming, J. M.; Taylor, B. D.; Obenschain, K.

    2016-11-01

    Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

  14. Dirac Induction for loop groups

    NARCIS (Netherlands)

    Posthuma, H.

    2011-01-01

    Using a coset version of the cubic Dirac operators for affine Lie algebras, we give an algebraic construction of the Dirac induction homomorphism for loop group representations. With this, we prove a homogeneous generalization of the Weyl-Kac character formula and show compatibility with Dirac induc

  15. Five-loop massive tadpoles

    CERN Document Server

    Luthe, T

    2016-01-01

    We provide an update on a long-term project that aims at evaluating massive vacuum integrals at the five-loop frontier, with high precision and in various space-time dimensions. A number of applications are sketched, mainly concerning the determination of anomalous dimensions, for quantum field theories in four, three and two dimensions.

  16. Dismantling design for the loop rooms on the MR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Craig, D.; Fecitt, L. [NUKEM Limited, Dounreay (United Kingdom); Gorlinsky, Yu.E. [RRC Kurchatov Institute, Moscow (Russian Federation); Harman, N.F.; Jackson, R. [Serco Technical and Assurance Services, Warrington (United Kingdom); Kolyadin, V.I. [RRC Kurchatov Institute, Moscow (Russian Federation); Lobach, Yu.N., E-mail: lobach@kinr.kiev.u [Institute for Nuclear Research of NASU, pr.Nauki, 47, 03680 Kiev (Ukraine); Pavlenko, V.I. [RRC Kurchatov Institute, Moscow (Russian Federation)

    2009-12-15

    The recently completed international co-operation project was aimed at planning for decommissioning the MR reactor identified as a pilot plant for the decommissioning of the other shutdown reactors on the site. The MR reactor was a pool-type, materials testing reactor with the total thermal power of 50 MW which incorporated pressure tubes containing fuel under test. The MR facility includes the reactor with its nine loop rig rooms containing pumps, heat exchangers and experimental equipment as well as systems and equipment located in other buildings in the complex. The objective of the MR reactor decommissioning project was to identify dismantling equipment and the decommissioning methodology for the reactor, loop rooms and redundant services to permit the refit and re-use of the building for a different nuclear related purpose. The dismantling design comprises two separate, but combined, tasks, namely, the dismantling of reactor installation itself and dismantling of experimental loops. The techniques proposed to undertake the dismantling operations within the loop rooms are described. Two options have been developed for removing contaminated equipment from the high radiation field loop rooms and packaging the waste into approved waste containers. The benefits and detriments of both methods have been identified, which allows implementing the safe, timely and cost-effective decommissioning.

  17. 基于锁相环的液压风扇调速特性测试系统设计%Design on Testing System of Rotating Speed Regulation Character for a Hydraulic Fan Based on Phase Lock Loop

    Institute of Scientific and Technical Information of China (English)

    汤春球; 莫易敏

    2010-01-01

    为测试液压风扇调速特性,需要对大功率电机进行高精度转速调节控制.介绍风扇调速特性测试系统的设计方案,采用锁相环(Phase Lock Loop)技术实现电机转速的高精度测量,并将转速信号反馈给PLC,通过PLC内置的PID控制算法,控制变频器的输出频率,实现交流电机转速的高精度调节控制,转速控制精度优于1 r/min.

  18. High Tc superconducting small loop antenna

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Mehler, M.J.; Maclean, T.S.M.; Lancaster, M.J.; Gough, C.E. (Univ. of Birmingham (UK)); Alford, N. (I.C.I. Advanced Materials Div., Runcorn (UK))

    1989-12-01

    The improvement in the radiation efficiency of an electrically small loop antenna is analysed when it is fabricated from a superconductor, and experimental results for a liquid nitrogen cooled, ceramic superconducting loop at 450MHz are presented. (orig.).

  19. Crystal packing effects on protein loops.

    Science.gov (United States)

    Rapp, Chaya S; Pollack, Rena M

    2005-07-01

    The effects of crystal packing on protein loop structures are examined by (1) a comparison of loops in proteins that have been crystallized in alternate packing arrangements, and (2) theoretical prediction of loops both with and without the inclusion of the crystal environment. Results show that in a minority of cases, loop geometries are dependent on crystal packing effects. Explicit representation of the crystal environment in a loop prediction algorithm can be used to model these effects and to reconstruct the structures, and relative energies, of a loop in alternative packing environments. By comparing prediction results with and without the inclusion of the crystal environment, the loop prediction algorithm can further be used to identify cases in which a crystal structure does not represent the most stable state of a loop in solution. We anticipate that this capability has implications for structural biology.

  20. Modified Continuous Loop Technique for microvascular anastomosis

    Directory of Open Access Journals (Sweden)

    Kumar Pramod

    2001-01-01

    Full Text Available A modified method of continuous loop technique for microvascular anastomosis is described. The handling of loop is easier & even last suture is placed under vision. This makes the microvascular anastomosis easier and simpler.

  1. Fingerprinting Hydrogen in Core-Collapse Supernovae

    Science.gov (United States)

    Nance, Sarafina; Parrent, Jerod; Soderberg, Alicia Margarita

    2016-01-01

    This is a preliminary report on the mass of remaining hydrogen envelopes for stars massive enough to explode under core collapse. Using the stellar evolution code, MESA, our initial findings suggest that a significant fraction of massive stars with M_ZAMS = 20-60 Msun lose all but 10^-3 Msun -10^-1 Msun as they near eventual core collapse. This result is dependent on the mass-loss prescription, degree of rotation, metallicity, rates of nuclear burning in the core, and the final stellar configuration. Nevertheless, each of our test cases include a few stars that retain trace amounts of surface hydrogen, which would then be detected as faint H in type IIb/Ib/Ic supernova spectra. We also compare our findings to the progenitor candidate identified for iPTF13bvn using the most recent photometric corrections. We agree with the previous conclusion found by Groh et al. (2013) that the progenitor had an initial mass of 32 Msun, but now with an additional condition of 0.06 Msun of hydrogen on its surface just prior to the explosion. We demonstrate through our study that not all Type Ib supernovae are fully devoid of hydrogen at the time of explosion, which has implications for the nature of the progenitor star and thus provides impetus for a revised classification scheme for 'stripped envelope' supernovae. This work was supported in part by the NSF REU and DoD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution.

  2. Current control loop design and analysis based on resonant regulators for microgrid applications

    DEFF Research Database (Denmark)

    Federico, de Bosio; Pastorelli, Michelle; de Sousa Ribeiro, Luiz Antonio

    2015-01-01

    Voltage and current control loops play an important role in the performance of microgrids employing power electronics voltage source inverters. Correct design of feedback loops is essential for the proper operation of these systems. This paper analyzes the influence of state feedback cross......-coupling in the design of resonant regulators for inner current loops in power converters operating in standalone microgrids. It is also demonstrated that the effect of state feedback cross-coupling degrades the performance of the control loops by increasing the steady-state error. Different resonant regulators...... structures are analyzed and compared, performing experimental tests to validate the results of the theoretical analysis....

  3. Resumming the POPE at One Loop

    CERN Document Server

    Lam, Ho Tat

    2016-01-01

    The Pentagon Operator Product Expansion represents polygonal Wilson loops in planar $\\mathcal{N}=4$ super Yang-Mills in terms of a series of flux tube excitations for finite coupling. We demonstrate how to re-sum this series at the one loop level for the hexagonal Wilson loop dual to the six-point MHV amplitude. By summing over a series of effective excitations we find expressions which integrate to logarithms and polylogarithms, reproducing the known one-loop result.

  4. Loop Equations in Abelian Gauge Theories

    CERN Document Server

    Di Bartolo, C; Pe~na, F; Bartolo, Cayetano Di; Leal, Lorenzo; Peña, Francisco

    2005-01-01

    The equations obeyed by the vacuum expectation value of the Wilson loop of Abelian gauge theories are considered from the point of view of the loop-space. An approximative scheme for studying these loop-equations for lattice Maxwell theory is presented. The approximation leads to a partial difference equation in the area and length variables of the loop, and certain physically motivated ansatz is seen to reproduce the mean field results from a geometrical perspective.

  5. Estimation of complex permittivity using loop antenna

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2004-01-01

    A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna.......A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna....

  6. Estimation of complex permittivity using loop antenna

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2004-01-01

    A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna.......A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna....

  7. Design of PID controllers in double feedback loops for SISO systems with set-point filters.

    Science.gov (United States)

    Vijayan, V; Panda, Rames C

    2012-07-01

    A PID controller is widely used to control industrial processes that are mostly open loop stable or unstable. Selection of proper feedback structure and controller tuning helps to improve the performance of the loop. In this paper a double-feedback loop/method is used to achieve stability and better performance of the process. The internal feedback is used for stabilizing the process and the outer loop is used for good setpoint tracking. An internal model controller (IMC) based PID method is used for tuning the outer loop controller. Autotuning based on relay feedback or the Ziegler-Nichols method can be used for tuning an inner loop controller. A tuning parameter (λ) that is used to tune IMC-PID is used as a time constant of a setpoint filter that is used for reducing the peak overshoot. The method has been tested successfully on many low order processes.

  8. Speed Loop Control of PMSM Driving Electric Vehicle

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    Various simulation models are set up and closed speed loop control strategy of PMSM is proposed based on flux weakening control in this paper. First the model of maximum torque per ampere(MTPA) is modeled based on mathematical models and gave the corresponding simulation tests. Second the formula...

  9. Capillary Pump Loop (CPL) heat pipe development status report

    Science.gov (United States)

    1982-01-01

    The capillary pump loop (CPL) was re-introduced as a potential candidate for the management of large heat loads. It is currently being evaluated for application in the thermal management of large space structures. Test efforts were conducted to establish the feasibility of the CPL heat pipe design.

  10. Cyclic coordinate descent: A robotics algorithm for protein loop closure.

    Science.gov (United States)

    Canutescu, Adrian A; Dunbrack, Roland L

    2003-05-01

    In protein structure prediction, it is often the case that a protein segment must be adjusted to connect two fixed segments. This occurs during loop structure prediction in homology modeling as well as in ab initio structure prediction. Several algorithms for this purpose are based on the inverse Jacobian of the distance constraints with respect to dihedral angle degrees of freedom. These algorithms are sometimes unstable and fail to converge. We present an algorithm developed originally for inverse kinematics applications in robotics. In robotics, an end effector in the form of a robot hand must reach for an object in space by altering adjustable joint angles and arm lengths. In loop prediction, dihedral angles must be adjusted to move the C-terminal residue of a segment to superimpose on a fixed anchor residue in the protein structure. The algorithm, referred to as cyclic coordinate descent or CCD, involves adjusting one dihedral angle at a time to minimize the sum of the squared distances between three backbone atoms of the moving C-terminal anchor and the corresponding atoms in the fixed C-terminal anchor. The result is an equation in one variable for the proposed change in each dihedral. The algorithm proceeds iteratively through all of the adjustable dihedral angles from the N-terminal to the C-terminal end of the loop. CCD is suitable as a component of loop prediction methods that generate large numbers of trial structures. It succeeds in closing loops in a large test set 99.79% of the time, and fails occasionally only for short, highly extended loops. It is very fast, closing loops of length 8 in 0.037 sec on average.

  11. Polyhedra in loop quantum gravity

    CERN Document Server

    Bianchi, Eugenio; Speziale, Simone

    2010-01-01

    Interwiners are the building blocks of spin-network states. The space of intertwiners is the quantization of a classical symplectic manifold introduced by Kapovich and Millson. Here we show that a theorem by Minkowski allows us to interpret generic configurations in this space as bounded convex polyhedra in Euclidean space: a polyhedron is uniquely described by the areas and normals to its faces. We provide a reconstruction of the geometry of the polyhedron: we give formulas for the edge lengths, the volume and the adjacency of its faces. At the quantum level, this correspondence allows us to identify an intertwiner with the state of a quantum polyhedron, thus generalizing the notion of quantum tetrahedron familiar in the loop quantum gravity literature. Moreover, coherent intertwiners result to be peaked on the classical geometry of a polyhedron. We discuss the relevance of this result for loop quantum gravity. In particular, coherent spin-network states with nodes of arbitrary valence represent a collection...

  12. Nucleosome repositioning via loop formation

    CERN Document Server

    Kulic, M L

    2002-01-01

    Active (catalysed) and passive (intrinsic) nucleosome repositioning is known to be a crucial event during the transcriptional activation of certain eucaryotic genes. Here we consider theoretically the intrinsic mechanism and study in detail the energetics and dynamics of DNA-loop-mediated nucleosome repositioning, as previously proposed by Schiessel et al. (H. Schiessel, J. Widom, R. F. Bruinsma, and W. M. Gelbart. 2001. {\\it Phys. Rev. Lett.} 86:4414-4417). The surprising outcome of the present study is the inherent nonlocality of nucleosome motion within this model -- being a direct physical consequence of the loop mechanism. On long enough DNA templates the longer jumps dominate over the previously predicted local motion, a fact that contrasts simple diffusive mechanisms considered before. The possible experimental outcome resulting from the considered mechanism is predicted, discussed and compared to existing experimental findings.

  13. Loop Diuretics in Clinical Practice.

    Science.gov (United States)

    Oh, Se Won; Han, Sang Youb

    2015-06-01

    Diuretics are commonly used to control edema across various clinical fields. Diuretics inhibit sodium reabsorption in specific renal tubules, resulting in increased urinary sodium and water excretion. Loop diuretics are the most potent diuretics. In this article, we review five important aspects of loop diuretics, in particular furosemide, which must be considered when prescribing this medicine: (1) oral versus intravenous treatment, (2) dosage, (3) continuous versus bolus infusion, (4) application in chronic kidney disease patients, and (5) side effects. The bioavailability of furosemide differs between oral and intravenous therapy. Additionally, the threshold and ceiling doses of furosemide differ according to the particular clinical condition of the patient, for example in patients with severe edema or chronic kidney disease. To maximize the efficiency of furosemide, a clear understanding of how the mode of delivery will impact bioavailability and the required dosage is necessary.

  14. Renormalized Polyakov loops in various representations in finite temperature SU(2) gauge theory

    CERN Document Server

    Huebner, K

    2008-01-01

    We present results for the renormalized Polyakov loop in the three lowest irreducible representations of SU(2) gauge theory at finite temperature. We will discuss their scaling behavior near $T_c$ and test Casimir scaling in the deconfined phase. Moreover, we will compare these results to calculations for the renormalized Polyakov loops in several representations in the SU(3) gauge theory.

  15. Deconfinement and virtual quark loops

    Science.gov (United States)

    Çelik, T.; Engels, J.; Satz, H.

    1983-12-01

    We calculate paer Monte Carlo evaluation on an 83 × 3 lattice the energy density ɛG of the gluon sector of QCD, including virtual quark loops up to the fourth power in the hopping parameter expansion. For light quarks of one flavour, we observe at T/ΛL 95 +/- 10 a rapid variation of ɛG in T, accompanied by strong fluctuations from iteration to iteration. as clear signal of the deconfinement transition.

  16. Theoretical and Experimental Dissection of DNA Loop-Mediated Repression

    Science.gov (United States)

    Boedicker, James Q.; Garcia, Hernan G.; Phillips, Rob

    2013-01-01

    Transcriptional networks across all domains of life feature a wide range of regulatory architectures. Theoretical models now make clear predictions about how key parameters describing those architectures modulate gene expression, and the ability to construct genetic circuits with tunable parameters enables precise tests of such models. We dissect gene regulation through DNA looping by tuning network parameters such as repressor copy number, DNA binding strengths, and loop length in both thermodynamic models and experiments. Our results help clarify the short-length mechanical properties of DNA. PMID:23383841

  17. Ion energy storage for post-flare loops

    Science.gov (United States)

    Hudson, H. S.

    1985-01-01

    Low-energy non-thermal protons may have long lifetimes in coronal loops with low density and high temperature. If energy were stored in such protons in the initial phases of a solar flare, it could be released slowly during the later phases. Within the present observational limits for post-flare loops, this mechanism should be considered in addition to a field-line reconnection theory of the Kopp and Pneuman type. The thin-target gamma ray emission from the trapped protons is below present limits, but more sensitive observations can test the hypothesis.

  18. Theoretical and Experimental Dissection of DNA Loop-Mediated Repression

    Science.gov (United States)

    Boedicker, James Q.; Garcia, Hernan G.; Phillips, Rob

    2013-01-01

    Transcriptional networks across all domains of life feature a wide range of regulatory architectures. Theoretical models now make clear predictions about how key parameters describing those architectures modulate gene expression, and the ability to construct genetic circuits with tunable parameters enables precise tests of such models. We dissect gene regulation through DNA looping by tuning network parameters such as repressor copy number, DNA binding strengths, and loop length in both thermodynamic models and experiments. Our results help clarify the short-length mechanical properties of DNA.

  19. Quantum Reduced Loop Gravity and the foundation of Loop Quantum Cosmology

    CERN Document Server

    Alesci, Emanuele

    2016-01-01

    Quantum Reduced Loop Gravity is a promising framework for linking Loop Quantum Gravity and the effective semiclassical dynamics of Loop Quantum Cosmology. We review its basic achievements and its main perspectives, outlining how it provides a quantum description of the Universe in terms of a cuboidal graph which constitutes the proper framework for applying loop techniques in a cosmological setting.

  20. Ponderomotive Acceleration in Coronal Loops

    CERN Document Server

    Dahlburg, R B; Taylor, B D; Obenschain, K

    2016-01-01

    Ponderomotive acceleration has been asserted to be a cause of the First Ionization Potential (FIP) effect, the by now well known enhancement in abundance by a factor of 3-4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a "byproduct" of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of a coronal loops with an axial magnetic field from 0.005 Teslas to 0.02 Teslas and lengths from 25000 km to 75000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets...

  1. Massive loop corrections for collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Yundin, Valery

    2012-02-01

    In this thesis we discuss the problem of evaluation of tensor integrals appearing in a typical one-loop Feynman diagram calculation. We present a computer library for the numerical evaluation of tensor integrals with up to 5 legs and arbitrary kinematics. The code implements algorithms based on the formalism which avoids the appearance of inverse Gram determinants in the reduction of pentagon diagrams. The Gram determinants of box integrals are isolated in the set of new basis integrals by using dimensional recurrence relations. These integrals are then evaluated by dimensional recurrence or expansion in small Gram determinant, which is improved by Pade extrapolation. A cache system allows reuse of identical building blocks and increases the efficiency. After describing the cross checks and accuracy tests, we show a sample application to the evaluation of five gluon helicity amplitudes, which is compared with the output of the program NGluon. In the last part the program is applied to the calculation of the one-loop virtual corrections to the muon pair production with hard photon emission. The computation method is explained, followed by a discussion of renormalization and pole structure. Finally, we present numerical results for differential cross sections with kinematics of the KLOE and BaBar detectors.

  2. 宫颈液基细胞学检查、HPV分型、LEEP环状电切术在宫颈疾病中的诊治意义%Diagnostic and therapeutic significance of thinprep cytologic test, HPV genotyping and loop electrosurgical excision procedure for cervical diseases

    Institute of Scientific and Technical Information of China (English)

    谷新; 邓雷

    2012-01-01

    Objective To investigate the diagnostic and therapeutic significance and clinical value of thinprep cytologic test, HPV genotyping and loop electrosurgical excision procedure for cervical diseases. Methods From January to December 2010 in Enshi center hospital, 4 613 patients were taken gynecological examination and thinprep cytologic test, 336 cases with the positivity of thinprep cytologic test were taken electronic colposcopy and colposcopic cervical biopsy, diagnosed 125 cases of cervical intraepithelial neoplasia-like lesions and cervical cancer, they were taken HPV genotyping. cervical severe erosion and repeated physical therapy chronic cervicitis of CIN Ⅱ and some CIN I , and early diagnosis of cervical cancer conization were treated with loop electrosurgical excision procedure, the surgical removal of tissue were taken pathological examination. Results The diagnosis rate was 98.6% for cervical liquid-based brush cytology proposed line cervical biopsy of electronic colposcopy and colposcopy, HPV genotyping check, HPV genotyping check positive 125 cases and the the loop electrosurgical excision procedure after excision pathological examination, no case of intraoperative bleeding in the surgery, 5 cases with cervical wound after the scab off bleeding, and no case of postoperative infection. Conclusion Electronic colposcopy, thinprep cytologic test, HPV genotyping and cervical biopsy has important diagnostic value for cervical precancerous lesions; the loop electrosurgical excision procedure in the treatment of cervical disease has small risk of surgery, and simple operation, less bleeding and high success rate, loop electrosurgical excision has important clinical value in the diagnosis and treatment of cervical disease.%目的 探讨宫颈液基细胞学检查、HPV分型、LEEP环状电切术在宫颈疾病中的诊治意义及临床价值.方法 对2010年1~12月在恩施州中心医院就诊的4 613例患者行妇检、宫颈液基细胞学刷片检查,

  3. Closed-Loop and Activity-Guided Optogenetic Control

    Science.gov (United States)

    Grosenick, Logan; Marshel, James H.; Deisseroth, Karl

    2016-01-01

    Advances in optical manipulation and observation of neural activity have set the stage for widespread implementation of closed-loop and activity-guided optical control of neural circuit dynamics. Closing the loop optogenetically (i.e., basing optogenetic stimulation on simultaneously observed dynamics in a principled way) is a powerful strategy for causal investigation of neural circuitry. In particular, observing and feeding back the effects of circuit interventions on physiologically relevant timescales is valuable for directly testing whether inferred models of dynamics, connectivity, and causation are accurate in vivo. Here we highlight technical and theoretical foundations as well as recent advances and opportunities in this area, and we review in detail the known caveats and limitations of optogenetic experimentation in the context of addressing these challenges with closed-loop optogenetic control in behaving animals. PMID:25856490

  4. Loop-induced Neutrino Masses: A Case Study

    CERN Document Server

    Geng, Chao-Qiang; Tsai, Lu-Hsing

    2014-01-01

    We study the cocktail model in which the Majorana neutrino masses are generated by the so-called "cocktail" three-loop diagrams with the dark matter particle running in the loops. In particular, we give the correct analytic expressions of the neutrino masses in the model by the detailed calculation of the cocktail diagrams. Based on the reliable numerical calculation of the loop integrals, we explore the parameter space which can give the correct orders of neutrino masses while satisfying other experimental constraints, such as those from the neutrinoless double beta decay, low-energy lepton flavor violation processes, electroweak precision tests, and collider searches. As a result, the large couplings and the large mass difference between the two singly-charged (neutral) scalars are required.

  5. Modeling Phase-Locked Loops Using Verilog

    Science.gov (United States)

    2007-11-01

    a charge pump, the phase detector has a tri-state output that can drive a opamp loop filter directly. This signal is conditioned by the charge pump...then it can directly drive an opamp based loop filter. Most loop filters are based upon an integrator loop. The integrator loop filter is advantageous...replaced with an accumulator. The opamp circuit can be replaced by a digital filter using Z-transform theory z=exp(jwT), where T is the sampling

  6. An integrated tool for loop calculations: AITALC

    Science.gov (United States)

    Lorca, Alejandro; Riemann, Tord

    2006-01-01

    AITALC, a new tool for automating loop calculations in high energy physics, is described. The package creates Fortran code for two-fermion scattering processes automatically, starting from the generation and analysis of the Feynman graphs. We describe the modules of the tool, the intercommunication between them and illustrate its use with three examples. Program summaryTitle of the program:AITALC version 1.2.1 (9 August 2005) Catalogue identifier:ADWO Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWO Program obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Computer:PC i386 Operating system:GNU/ LINUX, tested on different distributions SuSE 8.2 to 9.3, Red Hat 7.2, Debian 3.0, Ubuntu 5.04. Also on SOLARIS Programming language used:GNU MAKE, DIANA, FORM, FORTRAN77 Additional programs/libraries used:DIANA 2.35 ( QGRAF 2.0), FORM 3.1, LOOPTOOLS 2.1 ( FF) Memory required to execute with typical data:Up to about 10 MB No. of processors used:1 No. of lines in distributed program, including test data, etc.:40 926 No. of bytes in distributed program, including test data, etc.:371 424 Distribution format:tar gzip file High-speed storage required:from 1.5 to 30 MB, depending on modules present and unfolding of examples Nature of the physical problem:Calculation of differential cross sections for ee annihilation in one-loop approximation. Method of solution:Generation and perturbative analysis of Feynman diagrams with later evaluation of matrix elements and form factors. Restriction of the complexity of the problem:The limit of application is, for the moment, the 2→2 particle reactions in the electro-weak standard model. Typical running time:Few minutes, being highly depending on the complexity of the process and the FORTRAN compiler.

  7. Flica: a code for the thermodynamic study of a reactor or a test loop; Programme FLICA etude thermodynamique d'un reacteur ou d'une boucle d'essai

    Energy Technology Data Exchange (ETDEWEB)

    Fajeau, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    This code handles the thermal problems of water loops or reactor cores under the following conditions: High or low pressure, steady state or transient behavior, one or two phases - Three-dimensional thermodynamic study of the flow in cylindrical geometry - Unidimensional study of heat transfer in heating elements - Neutronic studies can be coupled and a schematic representation of the safety rod behavior is given. The number of cells described in a flow cross-section is presently less than 20. This code is the logical following of FLID and CACTUS of which it constitutes a synthesis. (author) [French] Ce code permet de traiter les problemes thermiques d'une boucle ou d'un coeur de reacteur a eau dans les conditions suivantes: - Haute ou basse pression, regime permanent ou transitoire, simple ou double phase - Etude thermodynamique de l'ecoulement a 3 dimensions dans une geometrie cylindrique - Etude unidimensionnelle du transfert de chaleur dans les masses chauffantes - Possibilite de couplage avec la neutronique (reacteur point) et d'une representation schematique des actions de securite. Ce code dans lequel le nombre de cellules decrites dans une section droite de l'ecoulement est actuellement limite a 20 est la suite logique des codes FLID et CACTUS dont il constitue la synthese. (auteur)

  8. The space of states of quantum gravity in terms of loops and extended loops some remarks

    CERN Document Server

    Di Bartolo, C; Griego, J R; Pullin, J; Di Bartolo, Cayetano; Gambini, Rodolfo; Griego, Jorge; Pullin, Jorge

    1995-01-01

    This article reviews the status of several solutions to all the constraints of quantum gravity that have been proposed in terms of loops and extended loops. We discuss pitfalls of several of the results and in particular discuss the issues of covariance and regularization of the constraints in terms of extended loops. We also propose a formalism for ``thickened out loops'' which does not face the covariance problems of extended loops and may allow to regularize expressions in a consistent manner.

  9. Hyperstaticity and loops in frictional granular packings

    Science.gov (United States)

    Tordesillas, Antoinette; Lam, Edward; Metzger, Philip T.

    2009-06-01

    The hyperstatic nature of granular packings of perfectly rigid disks is analyzed algebraically and through numerical simulation. The elementary loops of grains emerge as a fundamental element in addressing hyperstaticity. Loops consisting of an odd number of grains behave differently than those with an even number. For odd loops, the latent stresses are exterior and are characterized by the sum of frictional forces around each loop. For even loops, the latent stresses are interior and are characterized by the alternating sum of frictional forces around each loop. The statistics of these two types of loop sums are found to be Gibbsian with a "temperature" that is linear with the friction coefficient μ when μ<1.

  10. The extended loop representation of quantum gravity

    CERN Document Server

    Di Bartolo, C; Griego, J R

    1995-01-01

    A new representation of Quantum Gravity is developed. This formulation is based on an extension of the group of loops. The enlarged group, that we call the Extended Loop Group, behaves locally as an infinite dimensional Lie group. Quantum Gravity can be realized on the state space of extended loop dependent wavefunctions. The extended representation generalizes the loop representation and contains this representation as a particular case. The resulting diffeomorphism and hamiltonian constraints take a very simple form and allow to apply functional methods and simplify the loop calculus. In particular we show that the constraints are linear in the momenta. The nondegenerate solutions known in the loop representation are also solutions of the constraints in the new representation. The practical calculation advantages allows to find a new solution to the Wheeler-DeWitt equation. Moreover, the extended representation puts in a precise framework some of the regularization problems of the loop representation. We sh...

  11. A LabVIEW model incorporating an open-loop arterial impedance and a closed-loop circulatory system.

    Science.gov (United States)

    Cole, R T; Lucas, C L; Cascio, W E; Johnson, T A

    2005-11-01

    While numerous computer models exist for the circulatory system, many are limited in scope, contain unwanted features or incorporate complex components specific to unique experimental situations. Our purpose was to develop a basic, yet multifaceted, computer model of the left heart and systemic circulation in LabVIEW having universal appeal without sacrificing crucial physiologic features. The program we developed employs Windkessel-type impedance models in several open-loop configurations and a closed-loop model coupling a lumped impedance and ventricular pressure source. The open-loop impedance models demonstrate afterload effects on arbitrary aortic pressure/flow inputs. The closed-loop model catalogs the major circulatory waveforms with changes in afterload, preload, and left heart properties. Our model provides an avenue for expanding the use of the ventricular equations through closed-loop coupling that includes a basic coronary circuit. Tested values used for the afterload components and the effects of afterload parameter changes on various waveforms are consistent with published data. We conclude that this model offers the ability to alter several circulatory factors and digitally catalog the most salient features of the pressure/flow waveforms employing a user-friendly platform. These features make the model a useful instructional tool for students as well as a simple experimental tool for cardiovascular research.

  12. Novel single-loop and double-loop knot stitch in comparison with the modified Mason-Allen stitch for rotator cuff repair.

    Science.gov (United States)

    Frosch, Stephan; Buchhorn, Gottfried; Hoffmann, Anja; Balcarek, Peter; Schüttrumpf, Jan Philipp; August, Florian; Stürmer, Klaus Michael; Walde, Hans Joachim; Walde, Tim Alexander

    2015-05-01

    In rotator cuff repair, strong and long-lasting suturing techniques that do not require additional implants are needed. This study examines the ultimate load to failure and the Young's modulus at the suture-tendon interface for a novel single-loop knot stitch and double-loop knot stitch. These values are compared to those of the modified Mason-Allen stitch. Twenty-four infraspinatus muscles with tendons were dissected from porcine shoulders (twelve Goettingen minipigs). The preparations were randomly allocated to three groups of eight samples. Load-to-failure testing of the single-loop knot stitch, the double-loop knot stitch and the mMAS were performed using a Zwick 1446 universal testing machine (Zwick-Roell AG, Ulm, Germany). The highest ultimate load to failure for the three techniques occurred with the double-loop knot stitch with a median value of 382.2 N (range 291.8-454.2 N). These values were significantly higher than those of the single-loop knot stitch, which had a median value of 259.5 N (range 139.6-366.3 N) and the modified Mason-Allen stitch, which had a median value of 309.3 N (range 84.55-382.9 N). The values of the single-loop knot stitch and the modified Mason-Allen stitch did not differ significantly. Regarding the Young's modulus, no significant differences were found between the double-loop knot stitch with a median value of 496.02 N/mm² (range 400.4-572.6 N/mm²) and the modified Mason-Allen stitch with 498.5 N/mm² (range 375.5-749.2 N/mm²) with respect to the stiffness of the suture-tendon complex. The median value for the Young's modulus of the single-loop knot stitch of 392.1 N/mm² (range 285.7-510.6 N/mm²) was significantly lower than those of the double-loop knot stitch and modified Mason-Allen stitch. This in vitro animal study demonstrated that both the single-loop knot stitch and the double-loop knot stitch have excellent ultimate load-to-failure properties when used for rotator cuff repair. The introduced single-loop knot stitch

  13. Boosted Fast Flux Loop Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Boosted Fast Flux Loop Project Staff

    2009-09-01

    The Boosted Fast Flux Loop (BFFL) project was initiated to determine basic feasibility of designing, constructing, and installing in a host irradiation facility, an experimental vehicle that can replicate with reasonable fidelity the fast-flux test environment needed for fuels and materials irradiation testing for advanced reactor concepts. Originally called the Gas Test Loop (GTL) project, the activity included (1) determination of requirements that must be met for the GTL to be responsive to potential users, (2) a survey of nuclear facilities that may successfully host the GTL, (3) conceptualizing designs for hardware that can support the needed environments for neutron flux intensity and energy spectrum, atmosphere, flow, etc. needed by the experimenters, and (4) examining other aspects of such a system, such as waste generation and disposal, environmental concerns, needs for additional infrastructure, and requirements for interfacing with the host facility. A revised project plan included requesting an interim decision, termed CD-1A, that had objectives of' establishing the site for the project at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL), deferring the CD 1 application, and authorizing a research program that would resolve the most pressing technical questions regarding GTL feasibility, including issues relating to the use of booster fuel in the ATR. Major research tasks were (1) hydraulic testing to establish flow conditions through the booster fuel, (2) mini-plate irradiation tests and post-irradiation examination to alleviate concerns over corrosion at the high heat fluxes planned, (3) development and demonstration of booster fuel fabrication techniques, and (4) a review of the impact of the GTL on the ATR safety basis. A revised cooling concept for the apparatus was conceptualized, which resulted in renaming the project to the BFFL. Before the subsequent CD-1 approval request could be made, a decision was made in April

  14. Geothermal Loop Experimental Facility. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    Research at the Geothermal Loop Experimental Facility was successfully concluded in September 1979. In 13,000 hours of operation over a three and one half year period, the nominal 10 megawatt electrical equivalent GLEF provided the opportunity to identify problems in working with highly saline geothermal fluids and to develop solutions that could be applied to a commercial geothermal power plant producing electricity. A seven and one half year period beginning in April 1972, with early well flow testing and ending in September 1979, with the completion of extensive facility and reservoir operations is covered. During this period, the facility was designed, constructed and operated in several configurations. A comprehensive reference document, addressing or referencing documentation of all the key areas investigated is presented.

  15. Loop quantum gravity: an outside view

    CERN Document Server

    Nicolai, Hermann C; Zamaklar, M; Nicolai, Hermann; Peeters, Kasper; Zamaklar, Marija

    2005-01-01

    We present a pedagogical review of loop quantum gravity, with the aim of enabling a precise but critical assessment of its achievements so far. Special attention is paid to the appearance of a large number of ambiguities in the theory, in particular in the formulation of the Hamiltonian constraint. We emphasise that the off-shell (`strong') closure of the constraint algebra is a crucial test of the consistency of the theory, and should be used as the main tool to select one (if any) of the proposed Hamiltonians. Developing suitable approximation methods to establish a connection with classical gravity on the one hand, and with the physics of elementary particles on the other, remains a major challenge.

  16. Non-linear (loop) quantum cosmology

    CERN Document Server

    Bojowald, Martin; Dantas, Christine C; Jaffe, Matthew; Simpson, David

    2012-01-01

    Inhomogeneous quantum cosmology is modeled as a dynamical system of discrete patches, whose interacting many-body equations can be mapped to a non-linear minisuperspace equation by methods analogous to Bose-Einstein condensation. Complicated gravitational dynamics can therefore be described by more-manageable equations for finitely many degrees of freedom, for which powerful solution procedures are available, including effective equations. The specific form of non-linear and non-local equations suggests new questions for mathematical and computational investigations, and general properties of non-linear wave equations lead to several new options for physical effects and tests of the consistency of loop quantum gravity. In particular, our quantum cosmological methods show how sizeable quantum corrections in a low-curvature universe can arise from tiny local contributions adding up coherently in large regions.

  17. Development of the ANL plant dynamics code and control strategies for the supercritical carbon dioxide Brayton cycle and code validation with data from the Sandia small-scale supercritical carbon dioxide Brayton cycle test loop.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

    2011-11-07

    . Modeling in the Plant Dynamics Code has been compared with available data from the Sandia National Laboratories (SNL) small-scale S-CO{sub 2} Brayton cycle demonstration that is being assembled in a phased approach currently at Barber-Nichols Inc. and at SNL in the future. The available data was obtained with an earlier configuration of the S-CO{sub 2} loop involving only a single-turbo-alternator-compressor (TAC) instead of two TACs, a single low temperature recuperator (LTR) instead of both a LTR and a high temperature recuperator (HTR), and fewer than the later to be installed full set of electric heaters. Due to the absence of the full heating capability as well as the lack of a high temperature recuperator providing additional recuperation, the temperature conditions obtained with the loop are too low for the loop conditions to be prototypical of the S-CO{sub 2} cycle.

  18. Singularities in loop quantum cosmology.

    Science.gov (United States)

    Cailleteau, Thomas; Cardoso, Antonio; Vandersloot, Kevin; Wands, David

    2008-12-19

    We show that simple scalar field models can give rise to curvature singularities in the effective Friedmann dynamics of loop quantum cosmology (LQC). We find singular solutions for spatially flat Friedmann-Robertson-Walker cosmologies with a canonical scalar field and a negative exponential potential, or with a phantom scalar field and a positive potential. While LQC avoids big bang or big rip type singularities, we find sudden singularities where the Hubble rate is bounded, but the Ricci curvature scalar diverges. We conclude that the effective equations of LQC are not in themselves sufficient to avoid the occurrence of curvature singularities.

  19. Loop equations from differential systems

    CERN Document Server

    Eynard, Bertrand; Marchal, Olivier

    2016-01-01

    To any differential system $d\\Psi=\\Phi\\Psi$ where $\\Psi$ belongs to a Lie group (a fiber of a principal bundle) and $\\Phi$ is a Lie algebra $\\mathfrak g$ valued 1-form on a Riemann surface $\\Sigma$, is associated an infinite sequence of "correlators" $W_n$ that are symmetric $n$-forms on $\\Sigma^n$. The goal of this article is to prove that these correlators always satisfy "loop equations", the same equations satisfied by correlation functions in random matrix models, or the same equations as Virasoro or W-algebra constraints in CFT.

  20. Cygnus Loop: A double bubble?

    CERN Document Server

    West, J; Reichardt, I; Stil, J; Kothes, R; Jaffe, T

    2016-01-01

    The Cygnus Loop is a well-studied supernova remnant (SNR) that has been observed across the electromagnetic spectrum. Although widely believed to be an SNR shell with a blow- out region in the south, we consider the possibility that this object is two SNRs projected along the same line-of-sight by using multi-wavelength images and modelling. Our results show that a model of two objects including some overlap region/interaction between the two objects has the best match to the observed data.

  1. Closed-loop neuromorphic benchmarks

    CSIR Research Space (South Africa)

    Stewart

    2015-11-01

    Full Text Available Benchmarks   Terrence C. Stewart 1* , Travis DeWolf 1 , Ashley Kleinhans 2 , Chris Eliasmith 1   1 University of Waterloo, Canada, 2 Council for Scientific and Industrial Research, South Africa   Submitted to Journal:   Frontiers in Neuroscience   Specialty... the study was exempt from ethical approval procedures.) Did the study presented in the manuscript involve human or animal subjects: No I v i w 1Closed-loop Neuromorphic Benchmarks Terrence C. Stewart 1,∗, Travis DeWolf 1, Ashley Kleinhans 2 and Chris...

  2. Loop Virasoro Lie conformal algebra

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Henan, E-mail: wuhenanby@163.com; Chen, Qiufan; Yue, Xiaoqing [Department of Mathematics, Tongji University, Shanghai 200092 (China)

    2014-01-15

    The Lie conformal algebra of loop Virasoro algebra, denoted by CW, is introduced in this paper. Explicitly, CW is a Lie conformal algebra with C[∂]-basis (L{sub i} | i∈Z) and λ-brackets [L{sub i} {sub λ} L{sub j}] = (−∂−2λ)L{sub i+j}. Then conformal derivations of CW are determined. Finally, rank one conformal modules and Z-graded free intermediate series modules over CW are classified.

  3. Using the Meeting Graph Framework to Minimise Kernel Loop Unrolling for Scheduled Loops

    Science.gov (United States)

    Bachir, Mounira; Gregg, David; Touati, Sid-Ahmed-Ali

    This paper improves our previous research effort [1] by providing an efficient method for kernel loop unrolling minimisation in the case of already scheduled loops, where circular lifetime intervals are known. When loops are software pipelined, the number of values simultaneously alive becomes exactly known giving better opportunities for kernel loop unrolling. Furthermore, fixing circular lifetime intervals allows us to reduce the algorithmic complexity of our method compared to [1] by computing a new research space for minimal kernel loop unrolling. The meeting graph (MG) is one of the [3] frameworks proposed in the literature which models loop unrolling and register allocation together in a common formal framework for software pipelined loops. Although MG significantly improves loop register allocation, the computed loop unrolling may lead to unpractical code growth.

  4. Are Coronal Loops Isothermal or Multithermal? Yes!

    CERN Document Server

    Schmelz, J T; Rightmire, L A; Kimble, J A; Del Zanna, G; Cirtain, J W; DeLuca, E E; Mason, H E

    2009-01-01

    Surprisingly few solar coronal loops have been observed simultaneously with TRACE and SOHO/CDS, and even fewer analyses of these loops have been conducted and published. The SOHO Joint Observing Program 146 was designed in part to provide the simultaneous observations required for in-depth temperature analysis of active region loops and determine whether these loops are isothermal or multithermal. The data analyzed in this paper were taken on 2003 January 17 of AR 10250. We used TRACE filter ratios, emission measure loci, and two methods of differential emission measure analysis to examine the temperature structure of three different loops. TRACE and CDS observations agree that Loop 1 is isothermal with Log T $=$ 5.85, both along the line of sight as well as along the length of the loop leg that is visible in the CDS field of view. Loop 2 is hotter than Loop 1. It is multithermal along the line of sight, with significant emission between 6.2 $<$ Log T $<$ 6.4, but the loop apex region is out of the CDS ...

  5. Gauge theory loop operators and Liouville theory

    Energy Technology Data Exchange (ETDEWEB)

    Drukker, Nadav [Humboldt Univ. Berlin (Germany). Inst. fuer Physik; Gomis, Jaume; Okuda, Takuda [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Teschner, Joerg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-10-15

    We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S{sup 4} - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)

  6. DESIGNING A FINITE STATE MACHINE SIMULATOR TO DETECT LOOPS FOR ALICE DETECTOR CONTROL SYSTEM

    CERN Document Server

    Yogatama, Bobbi Winema

    2017-01-01

    This paper present the design and implementation of a Finite State Machine simulator to provoke loops in ALICE Detector Control System (DCS). Loops in a Finite State Machine can be very harmful for the control system and need to be prevented. One way to prevent loops is to simulate the designed Finite State Machine using a simulator that can detect all of the possible conditions that can provoke loops. Further correction can then be made after the loops are detected in the control system. The proposed simulator is able to get the structure of any unknown FSM, get every datapoint elements that are associated with the FSM, and find every possible datapoint combinations that can provoke loops in the FSM. At the end of the project, we tested the simulator on a sample FSM with loops and a real FSM that belongs to the ALICE PHOton Spectrometer (PHOS). The testing results indicate that the simulator is able to detect every possible condition that can cause loops in the FSM.

  7. Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating Solar Power: Loop Experiments and Final Report

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, Joanna [ORNL; Bell, Jason R [ORNL; Felde, David K [ORNL; Joseph III, Robert Anthony [ORNL; Qualls, A L [ORNL; Weaver, Samuel P [ORNL

    2013-02-01

    ORNL and subcontractor Cool Energy completed an investigation of higher-temperature, organic thermal fluids for solar thermal applications. Although static thermal tests showed promising results for 1-phenylnaphthalene, loop testing at temperatures to 450 C showed that the material isomerized at a slow rate. In a loop with a temperature high enough to drive the isomerization, the higher melting point byproducts tended to condense onto cooler surfaces. So, as experienced in loop operation, eventually the internal channels of cooler components such as the waste heat rejection exchanger may become coated or clogged and loop performance will decrease. Thus, pure 1-phenylnaphthalene does not appear to be a fluid that would have a sufficiently long lifetime (years to decades) to be used in a loop at the increased temperatures of interest. Hence a decision was made not to test the ORNL fluid in the loop at Cool Energy Inc. Instead, Cool Energy tested and modeled power conversion from a moderate-temperature solar loop using coupled Stirling engines. Cool Energy analyzed data collected on third and fourth generation SolarHeart Stirling engines operating on a rooftop solar field with a lower temperature (Marlotherm) heat transfer fluid. The operating efficiencies of the Stirling engines were determined at multiple, typical solar conditions, based on data from actual cycle operation. Results highlighted the advantages of inherent thermal energy storage in the power conversion system.

  8. Use of COTS Infrared Camera Arrays for Enhanced Human in the Loop Data Collection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate use of Microsoft Kinect infrared cameras in the application of passive data collection during human-in- the-loop (HITL) tests. Low-cost COTS cameras are...

  9. Higher Loop Nonplanar Anomalous Dimensions from Symmetry

    CERN Document Server

    Koch, Robert de Mello; Messamah, Ilies

    2013-01-01

    In this article we study the action of the one loop dilatation operator on operators with a classical dimension of order N. These operators belong to the su(2) sector and are constructed using two complex fields Y and Z. For these operators non-planar diagrams contribute already at the leading order in N and the planar and large N limits are distinct. The action of the one loop and the two loop dilatation operator reduces to a set of decoupled oscillators and factorizes into an action on the Z fields and an action on the Y fields. Direct computation has shown that the action on the Y fields is the same at one and two loops. In this article, using the su(2) symmetry algebra as well as structural features of field theory, we give compelling evidence that the factor in the dilatation operator that acts on the Ys is given by the one loop expression, at any loop order.

  10. Abstract Acceleration of General Linear Loops

    OpenAIRE

    2014-01-01

    International audience; We present abstract acceleration techniques for computing loop invariants for numerical programs with linear assignments and conditionals. Whereas abstract interpretation techniques typically over-approximate the set of reachable states iteratively, abstract acceleration captures the effect of the loop with a single, non-iterative transfer function applied to the initial states at the loop head. In contrast to previous acceleration techniques, our approach applies to a...

  11. LMFBR with booster pump in pumping loop

    Science.gov (United States)

    Rubinstein, H.J.

    1975-10-14

    A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation.

  12. Wilson Loops in Open String Theory

    Science.gov (United States)

    Shiraishi, Kiyoshi

    Wilson loop elements on torus are introduced into the partition function of open strings as Polyakov’s path integral at one-loop level. Mass spectra from compactification and expected symmetry breaking are illustrated by choosing the correct weight for the contributions from annulus and Möbius strip. We show that Jacobi’s imaginary transformation connects the mass spectra with the Wilson loops. The application to thermopartition function and cosmological implications are briefly discussed.

  13. Wilson Loops in Open String Theory

    CERN Document Server

    Shiraishi, Kiyoshi

    2012-01-01

    Wilson loop elements on torus are introduced into the partition function of open strings as Polyakov's path integral at one-loop level. Mass spectra from compactification and expected symmetry breaking are illustrated by choosing the correct weight for the contributions from annulus and M\\"obius strip. We show that Jacobi's imaginary transformation connects the mass spectra with the Wilson loops. The application to thermopartition function and cosmological implications are briefly discussed.

  14. All Digital Phase-Locked Loop

    OpenAIRE

    Marijan Jurgo

    2013-01-01

    The paper reviews working principles of phase-locked loop and drawbacks of classical PLL structure in nanometric technologies. It is proposed to replace the classical structure by all-digital phase-locked loop structure. Authors described the main blocks of all-digital phase-locked loop (time to digital converter and digitally controlled oscillator) and overviewed the quantization noise arising in these blocks as well as its minimization strategies. The calculated inverter delay in 65 nm CMOS...

  15. Magnetic Monopole in the Loop Representation

    CERN Document Server

    Leal, L; Leal, Lorenzo; Lopez, Alexander

    2004-01-01

    We quantize the electromagnetic field in the presence of a static magnetic monopole, within the loop-representation formalism. We find that the loop-dependent wave functional becomes multivalued, in the sense that it acquires a dependence on the surfaces bounded by the loop. This generalizes what occurs in quantum mechanics in multiply connected spaces. When Dirac's quantization condition holds, this surface-dependence disappears, together with the effect of the monopole on the electromagnetic field.

  16. A Note on Loop Amplitudes in QED

    CERN Document Server

    Brandhuber, Andreas; Vincon, Massimiliano

    2009-01-01

    We consider the two-loop four-point amplitude in N=2 super QED, and show that there exists an approximate recursive structure similar to that captured by the ABDK/BDS ansatz for MHV amplitudes in N=4 super Yang-Mills. Furthermore, we present a simple relation between the box coefficients of one-loop photon MHV amplitudes in (super) QED, and sums of box coefficients of one-loop MHV amplitudes in (super) Yang-Mills.

  17. Human-in-the-loop simulations

    CERN Document Server

    Rothrock, Ling

    2011-01-01

    ""Human-in-the-Loop Simulations"" is a compilation of articles from experts in the design, development, and use of human-in-the-loop simulations. The first section of the handbook consists of papers on fundamental concepts in human-in-the-loop simulations, such as object-oriented simulation development, interface design and development, and performance measurement. The second section includes papers from researchers who utilized HITL simulations to inform models of cognitive processes to include decision making and metacognition. The last section describes human-in-the-loop processes for compl

  18. The emergy analysis of loop circuit.

    Science.gov (United States)

    Cao, Kai; Feng, Xiao

    2008-12-01

    Emergy analysis can analyze the resource utilization and environmental performance of a system. Loop circuit is a common structure in the process industry, but when emergy analysis is carried out to such structure, mistakes such as emergy double counting often occur. To avoid emergy double counting, two types of loop circuit-direct loop circuit and indirect loop circuit-are theoretically distinguished, and the methods to avoid such mistake are proposed. Finally, PVC production and vinyl acetate production are adopted to demonstrate the methods.

  19. Pseudoautomorphisms of Bruck loops and their generalizations

    CERN Document Server

    Greer, Mark

    2012-01-01

    We show that in a weak commutative inverse property loop, such as a Bruck loop, if $\\alpha$ is a right [left] pseudoautomorphism with companion $c$, then $c$ [$c^2$] must lie in the left nucleus. In particular, for any such loop with trivial left nucleus, every right pseudoautomorphism is an automorphism and if the squaring map is a permutation, then every left pseudoautomorphism is an automorphism as well. We also show that every pseudoautomorphism of a commutative inverse property loop is an automorphism, generalizing a well-known result of Bruck.

  20. On Bruck Loops of 2-power Exponent

    CERN Document Server

    Baumeister, Barbara; Stroth, Gernot

    2009-01-01

    We classify "nice" loop envelopes to Bruck loops of 2-power exponent under the assumption that every nonabelian simple section of $G$ is either passive or isomorphic to $\\PSL_2(q)$, $q-1 \\ge 4$ a 2-power. The hypothesis is verified in a separate paper. This paper is a continuation of the work by Aschbacher, Kinyon and Phillips on finite Bruck loops [AKP]. In [BS3] we applied these results and get a neat description of the structure of the finite Bruck loops.

  1. Loops with exponent three in all isotopes

    CERN Document Server

    Kinyon, Michael

    2011-01-01

    It was shown by van Rees \\cite{vR} that a latin square of order $n$ cannot have more than $n^2(n-1)/18$ latin subsquares of order 3. He conjectured that this bound is only achieved if $n$ is a power of 3. We show that it can only be achieved if $n\\equiv3\\bmod6$. We also state several conditions that are equivalent to achieving the van Rees bound. One of these is that the Cayley table of a loop achieves the van Rees bound if and only if every loop isotope has exponent 3. We call such loops \\emph{van Rees loops} and show that they form an equationally defined variety. We also show that (1) In a van Rees loop, any subloop of index 3 is normal, (2) There are exactly 6 nonassociative van Rees loops of order 27 with a non-trivial nucleus, (3) There is a Steiner quasigroup associated with every van Rees loop and (4) Every Bol loop of exponent 3 is a van Rees loop.

  2. Polyakov loop modeling for hot QCD

    Science.gov (United States)

    Fukushima, Kenji; Skokov, Vladimir

    2017-09-01

    We review theoretical aspects of quantum chromodynamics (QCD) at finite temperature. The most important physical variable to characterize hot QCD is the Polyakov loop, which is an approximate order parameter for quark deconfinement in a hot gluonic medium. Additionally to its role as an order parameter, the Polyakov loop has rich physical contents in both perturbative and non-perturbative sectors. This review covers a wide range of subjects associated with the Polyakov loop from topological defects in hot QCD to model building with coupling to the Polyakov loop.

  3. Vertically Polarized Omnidirectional Printed Slot Loop Antenna

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

    2015-01-01

    A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

  4. Hanford Tank Farms Waste Feed Flow Loop Phase VI: PulseEcho System Performance Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Hopkins, Derek F.

    2012-11-21

    This document presents the visual and ultrasonic PulseEcho critical velocity test results obtained from the System Performance test campaign that was completed in September 2012 with the Remote Sampler Demonstration (RSD)/Waste Feed Flow Loop cold-test platform located at the Monarch test facility in Pasco, Washington. This report is intended to complement and accompany the report that will be developed by WRPS on the design of the System Performance simulant matrix, the analysis of the slurry test sample concentration and particle size distribution (PSD) data, and the design and construction of the RSD/Waste Feed Flow Loop cold-test platform.

  5. Overview of Loop Heat Pipe Operation

    Science.gov (United States)

    Ku, Jentung

    1999-01-01

    Loop heat pipes (LHP's) are two-phase heat transfer devices that utilize the evaporation and condensation of a working fluid to transfer heat, and the capillary forces developed in the porous wicks to circulate the fluid. The LHP was first developed in the former Soviet Union in the early 1980s, about the same time that the capillary pumped loop (CPL) was developed in the United States. The LHP is known for its high pumping capability and robust operation mainly due to the use of fine-pored metal wicks and an integral evaporator/hydro-accumulator design. The LHP technology is rapidly gaining acceptance in aerospace community. It is the baseline design for thermal control of several spacecraft, including NASA's GLAS and Chemistry, ESA's ATLID, CNES' STENTOR, RKA's OBZOR, and several commercial satellites. Numerous LHP papers have been published since the mid-1980's. Most papers presented test results and discussions on certain specific aspects of the LHP operation. LHP's and CPL's show many similarities in their operating principles and performance characteristics. However, they also display significant differences in many aspects of their operation. Some of the LHP behaviors may seem strange or mysterious, even to experienced CPL practitioners. The main purpose of this paper is to present a systematic description of the operating principles and thermal-hydraulic behaviors of LHP'S. LHP operating principles will be given first, followed by a description of the thermal-hydraulics involved in LHP operation. Operating characteristics and important parameters affecting the LHP operation will then be described in detail. Peculiar behaviors of the LHP, including temperature hysteresis and temperature overshoot during start-up, will be explained. For simplicity, most discussions will focus upon LHP's with a single evaporator and a single condenser, but devices with multiple evaporators and condensers will also be discussed. Similarities and differences between LHP's and

  6. High heat flux loop heat pipes

    Science.gov (United States)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m2. This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m2. This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m2.K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser.

  7. Vehicle in the Loop (VIL); Simulations- und Testumgebung fuer Fahrerassistenzsysteme

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Th. [Lehrstuhl fuer Realzeit-Computersysteme, TU Muenchen (Germany); Siedersberger, K.H.; Zavrel, M.; Breu, A.; Maurer, M. [Audi AG, Ingolstadt (Germany)

    2005-07-01

    Up to now the reproducible and safe test of driver assistance systems proves to be very difficult. This is true especially for collision mitigation tests. In this article today's state of the art of test and simulation methods for driver assistance systems is summarised at first. Then a new simulation and test environment is presented: In future the function of driver assistance systems can be tested and evaluated economically, reproducibly and most important without danger for the test person and test vehicle. To achieve this the real test vehicle is integrated into a traffic simulation by means of a vehicle in the loop (VIL) configuration. The vehicle does not move in real traffic but on open spaces or blocked off roads. It resorts to synthetic sensor data of a partly simulated environment. Methods and instruments of the augmented reality integrate the test driver into the synthetic outside traffic. (orig.)

  8. Research on switching throughput of traffic manager in core routers

    Institute of Scientific and Technical Information of China (English)

    SUN Chang-hua; LIU Bin; LI Wen-jie

    2006-01-01

    A general model is made to analyze switching throughput of traffic manager in core routers.By designing a real traffic manager that uses the OC-48c interface,the whole system is analyzed and it is pointed out that at least four HSSLs should be employed per CSIX interface when using Vitesse's GigaStream switch chipset.Meanwhile,at the CSIX interface,the Cframe should be constructed according to the actual size of the last cell of each IP packet.The above principles can guarantee forwarding of IP packets at line rate.A general relationship between throughput and buffering scheme of IP packets in the external memory is given,which is useful in the design of switch fabric in core routers.

  9. 44Ti and 56Ni in core-collapse supernovae

    CERN Document Server

    Magkotsios, Georgios; Wiescher, Michael; Fryer, Christopher L; Hungerford, Aimee; Young, Patrick; Bennett, Michael; Diehl, Steven; Herwig, Falk; Hirschi, Raphael; Pignatari, Marco; Rockefeller, Gabriel

    2008-01-01

    We investigate the physical conditions where 44Ti and 56Ni are created in core-collapse supernovae. In this preliminary work we use a series of post-processing network calculations with parametrized expansion profiles that are representative of the wide range of temperatures, densities and electron-to-baryon ratios found in 3D supernova simulations. Critical flows that affect the final yields of 44Ti and 56Ni are assessed.

  10. Thermal Interface Evaluation of Heat Transfer from a Pumped Loop to Titanium-Water Thermosyphons

    Science.gov (United States)

    Jaworske, Donald A.; Sanzi, James L.; Gibson, Marc A.; Sechkar, Edward A.

    2009-01-01

    Titanium-water thermosyphons are being considered for use in the heat rejection system for lunar outpost fission surface power. Key to their use is heat transfer between a closed loop heat source and the heat pipe evaporators. This work describes laboratory testing of several interfaces that were evaluated for their thermal performance characteristics, in the temperature range of 350 to 400 K, utilizing a water closed loop heat source and multiple thermosyphon evaporator geometries. A gas gap calorimeter was used to measure heat flow at steady state. Thermocouples in the closed loop heat source and on the evaporator were used to measure thermal conductance. The interfaces were in two generic categories, those immersed in the water closed loop heat source and those clamped to the water closed loop heat source with differing thermal conductive agents. In general, immersed evaporators showed better overall performance than their clamped counterparts. Selected clamped evaporator geometries offered promise.

  11. CURRENT STATUS OF INSTRUMENTATION FOR A FLUORIDE SALT HEAT TRANSPORT DEMONSTRATION LOOP

    Energy Technology Data Exchange (ETDEWEB)

    Kisner, Roger A [ORNL; Holcomb, David Eugene [ORNL

    2010-01-01

    A small forced convection liquid fluoride salt loop is under construction at Oak Ridge National Laboratory (ORNL) to examine the heat transfer behavior of FLiNaK in a heated pebble bed. Loop operation serves several purposes: (1) reestablishing the infrastructure necessary for fluoride salt loop testing, (2) demonstrating a wireless heating technique for simulating pebble type fuel, (3) demonstration of the integration of silicon carbide (SiC) and metallic components into a liquid salt loop, and (4) demonstration of the functionality of distinctive instrumentation required for liquid fluoride salts. Loop operation requires measurement of a broad set of process variables including temperature, flow, pressure, and level. Coolant chemistry measurements (as a corrosion indicator) and component health monitoring are also important for longer-term operation. Two dominating factors in sensor and instrument selection are the high operating temperature of the salt and its chemical environment.

  12. Thermal and non-thermal emission from reconnecting twisted coronal loops

    CERN Document Server

    Pinto, R; Browning, P K; Vilmer, N

    2016-01-01

    Twisted magnetic fields should be ubiquitous in the solar corona. The magnetic energy contained in such twisted fields can be released during solar flares and other explosive phenomena. Reconnection in helical magnetic coronal loops results in plasma heating and particle acceleration distributed within a large volume, including the lower coronal and chromospheric sections of the loops, and can be a viable alternative to the standard flare model, where particles are accelerated only in a small volume located in the upper corona. The goal of this study is to investigate the observational signatures of plasma heating and particle acceleration in kink-unstable twisted coronal loops using combination of MHD simulations and test-particle methods. The simulations describe the development of kink instability and magnetic reconnection in twisted coronal loops using resistive compressible MHD, and incorporate atmospheric stratification and large-scale loop curvature. The resulting distributions of hot plasma let us est...

  13. The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, K.A.

    2006-09-15

    We have calculated the Polyakov loop in representations D=3,6,8,10,15,15',24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Q anti Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below T{sub c}, binding energy of the gluelump and string breaking distances. Moreover, we could show Casimir scaling for the Polyakov loop in different representations in SU(3) pure gauge theory above T{sub c}. Diquark antitriplet and baryonic singlet free energies are related to the Q anti Q-singlet free energies by the Casimir as well. (orig.)

  14. R-loopDB: a database for R-loop forming sequences (RLFS) and R-loops

    Science.gov (United States)

    Jenjaroenpun, Piroon; Wongsurawat, Thidathip; Sutheeworapong, Sawannee; Kuznetsov, Vladimir A.

    2017-01-01

    R-loopDB (http://rloop.bii.a-star.edu.sg) was originally constructed as a collection of computationally predicted R-loop forming sequences (RLFSs) in the human genic regions. The renewed R-loopDB provides updates, improvements and new options, including access to recent experimental data. It includes genome-scale prediction of RLFSs for humans, six other animals and yeast. Using the extended quantitative model of RLFSs (QmRLFS), we significantly increased the number of RLFSs predicted in the human genes and identified RLFSs in other organism genomes. R-loopDB allows searching of RLFSs in the genes and in the 2 kb upstream and downstream flanking sequences of any gene. R-loopDB exploits the Ensembl gene annotation system, providing users with chromosome coordinates, sequences, gene and genomic data of the 1 565 795 RLFSs distributed in 121 056 genic or proximal gene regions of the covered organisms. It provides a comprehensive annotation of Ensembl RLFS-positive genes including 93 454 protein coding genes, 12 480 long non-coding RNA and 7 568 small non-coding RNA genes and 7 554 pseudogenes. Using new interface and genome viewers of R-loopDB, users can search the gene(s) in multiple species with keywords in a single query. R-loopDB provides tools to carry out comparative evolution and genome-scale analyses in R-loop biology. PMID:27899586

  15. UWB communication receiver feedback loop

    Science.gov (United States)

    Spiridon, Alex; Benzel, Dave; Dowla, Farid U.; Nekoogar, Faranak; Rosenbury, Erwin T.

    2007-12-04

    A novel technique and structure that maximizes the extraction of information from reference pulses for UWB-TR receivers is introduced. The scheme efficiently processes an incoming signal to suppress different types of UWB as well as non-UWB interference prior to signal detection. Such a method and system adds a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. Moreover, sampling the second order statistical function such as, for example, the autocorrelation function (ACF) of the received signal and matching it to the ACF samples of the original pulses for each transmitted bit provides a more robust UWB communications method and system in the presence of channel distortions.

  16. Wilson loops with arbitrary charges

    CERN Document Server

    Korcyl, Piotr; Wosiek, Jacek

    2014-01-01

    We discuss how to implement, in lattice gauge theories, external charges which are not commensurate with an elementary gauge coupling. It is shown that an arbitrary, real power of a standard Wilson loop (or Polyakov line) can be defined and consistently computed in lattice formulation of non-abelian, two dimensional gauge theories. However, such an observable can excite quantum states with integer fluxes only. Since the non-integer fluxes are not in the spectrum of the theory they cannot be created, no matter which observable is chosen. Also the continuum limit of above averages does not exist unless the powers in question are in fact integer. On the other hand, a new continuum limit exists, which is rather intuitive, and where above observables make perfect sense and lead to the string tension proportional to the square of arbitrary (non necessary commensurate with gauge coupling) charge.

  17. A Loop-philic Pseudoscalar

    CERN Document Server

    Li, Gang; Tang, Yi-Lei; Zhang, Chen; Zhou, Yang; Zhu, Shou-hua

    2015-01-01

    We construct a weakly-coupled renormalizable model to explain the 750 $\\mbox{GeV}$ diphoton excess. The 750 $\\mbox{GeV}$ resonance (denoted as $X(750)$) is interpreted as a pseudoscalar which comes from a complex singlet. The model also naturally provides a dark matter candidate. One most attractive feature of our model is that decays of $X(750)$ are all loop-induced so the diphoton rate is not diluted by unwanted tree level branching fractions. Relevant Yukawa interactions need not to be tuned to nearly non-perturbative region to explain the rate. The model is highly predictive, including the pseudoscalar nature of the new resonance, and two nearly mass-degenerate quarks carrying electric charge $5/3$ and $2/3$. In our model, rich phenomenology is expected with respect to collider searches, flavor physics and dark matter searches in various manners, if $X(750)$ can be pinned down by future LHC experiments.

  18. Lectures on Loop Quantum Gravity

    CERN Document Server

    Thiemann, T

    2003-01-01

    Quantum General Relativity (QGR), sometimes called Loop Quantum Gravity, has matured over the past fifteen years to a mathematically rigorous candidate quantum field theory of the gravitational field. The features that distinguish it from other quantum gravity theories are 1) background independence and 2) minimality of structures. Background independence means that this is a non-perturbative approach in which one does not perturb around a given, distinguished, classical background metric, rather arbitrary fluctuations are allowed, thus precisely encoding the quantum version of Einstein's radical perception that gravity is geometry. Minimality here means that one explores the logical consequences of bringing together the two fundamental principles of modern physics, namely general covariance and quantum theory, without adding any experimentally unverified additional structures. The approach is purposely conservative in order to systematically derive which basic principles of physics have to be given up and mu...

  19. Lose Your Loops with Numpy

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Developing in python is fast. Computation, however, can often be another story. Or at least that is how it may seem. When working with arrays and numerical datasets one can subvert many of python’s computational limitations by utilizing numpy. Numpy is python’s standard matrix computation library. Many python users only use numpy to store and generate arrays, failing to utilize one of python’s most powerful computational tools. By leveraging numpy’s ufuncs, aggregation, broadcasting and slicing/masking/indexing functionality one can cut back on slow python loops and increase the speed of their programs by as much as 100x. This talk aims at teaching attendees how to use these tools through toy examples.

  20. Design validation and performance of closed loop gas recirculation system

    Science.gov (United States)

    Kalmani, S. D.; Joshi, A. V.; Majumder, G.; Mondal, N. K.; Shinde, R. R.

    2016-11-01

    A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m2, with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C2H2F4), isobutane (iC4H10) and sulphur hexafluoride (SF6) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.

  1. A Looping-Based Model for Quenching Repression.

    Directory of Open Access Journals (Sweden)

    Yaroslav Pollak

    2017-01-01

    Full Text Available We model the regulatory role of proteins bound to looped DNA using a simulation in which dsDNA is represented as a self-avoiding chain, and proteins as spherical protrusions. We simulate long self-avoiding chains using a sequential importance sampling Monte-Carlo algorithm, and compute the probabilities for chain looping with and without a protrusion. We find that a protrusion near one of the chain's termini reduces the probability of looping, even for chains much longer than the protrusion-chain-terminus distance. This effect increases with protrusion size, and decreases with protrusion-terminus distance. The reduced probability of looping can be explained via an eclipse-like model, which provides a novel inhibitory mechanism. We test the eclipse model on two possible transcription-factor occupancy states of the D. melanogaster eve 3/7 enhancer, and show that it provides a possible explanation for the experimentally-observed eve stripe 3 and 7 expression patterns.

  2. Advancements in Development of Chemical-Looping Combustion: A Review

    Directory of Open Access Journals (Sweden)

    He Fang

    2009-01-01

    Full Text Available Chemical-looping combustion (CLC is a novel combustion technology with inherent separation of greenhouse CO2. Extensive research has been performed on CLC in the last decade with respect to oxygen carrier development, reaction kinetics, reactor design, system efficiencies, and prototype testing. Transition metal oxides, such as Ni, Fe, Cu, and Mn oxides, were reported as reactive species in the oxygen carrier particles. Ni-based oxygen carriers exhibited the best reactivity and stability during multiredox cycles. The performance of the oxygen carriers can be improved by changing preparation method or by making mixedoxides. The CLC has been demonstrated successfully in continuously operated prototype reactors based on interconnected fluidized-bed system in the size range of 0.3–50 kW. High fuel conversion rates and almost 100%  CO2 capture efficiencies were obtained. The CLC system with two interconnected fluidized-bed reactors was considered the most suitable reactor design. Development of oxygen carriers with excellent reactivity and stability is still one of the challenges for CLC in the near future. Experiences of building and operating the large-scale CLC systems are needed before this technology is used commercially. Chemical-looping reforming (CLR and chemical-looping hydrogen (CLH are novel chemical-looping techniques to produce synthesis gas and hydrogen deserving more attention and research.

  3. Automated Coronal Loop Identification Using Digital Image Processing Techniques

    Science.gov (United States)

    Lee, Jong K.; Gary, G. Allen; Newman, Timothy S.

    2003-01-01

    The results of a master thesis project on a study of computer algorithms for automatic identification of optical-thin, 3-dimensional solar coronal loop centers from extreme ultraviolet and X-ray 2-dimensional images will be presented. These center splines are proxies of associated magnetic field lines. The project is pattern recognition problems in which there are no unique shapes or edges and in which photon and detector noise heavily influence the images. The study explores extraction techniques using: (1) linear feature recognition of local patterns (related to the inertia-tensor concept), (2) parametric space via the Hough transform, and (3) topological adaptive contours (snakes) that constrains curvature and continuity as possible candidates for digital loop detection schemes. We have developed synthesized images for the coronal loops to test the various loop identification algorithms. Since the topology of these solar features is dominated by the magnetic field structure, a first-order magnetic field approximation using multiple dipoles provides a priori information in the identification process. Results from both synthesized and solar images will be presented.

  4. Polarization-maintaining fiber loop with double optical length and its application to fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    Changsheng Li; Chunxi Zhang; Ningfang Song; Hongjie Xu

    2011-01-01

    @@ A novel polarization maintaining fiber (PMP) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters, polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.%A novel polarization maintaining fiber (PMF) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters,polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.

  5. Open-loop experiments of resonator micro-optic gyro

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu-lin; ZHOU Ke-jiang

    2009-01-01

    An open-loop resonator micro-optic gyro (R-MOG) with a 6 cm-long waveguide-type ring resonator is set up using the phase modulation spectroscopy technique. In the experiment, according to the test parameters of the resonator, the shot-noise-limited sensitivity is estimated to be 1.07×10-4 rad/s. From the test demodulation signal, the gyro dynamic range of ±7.0×103 rad/s is obtained. Using different phase modulation frequencies, the open-loop gyro output signal is observed when the equivalent gyro rotation is applied to the aconstic-optical modulators (AOMs). The sensitivity of the R-MOG can be increased by some countermeasures against system noise.

  6. Relations between the loop transposition of DNA G-quadruplex and the catalytic function of DNAzyme.

    Science.gov (United States)

    Cheng, Mingpan; Zhou, Jun; Jia, Guoqing; Ai, Xuanjun; Mergny, Jean-Louis; Li, Can

    2017-08-01

    The structures of DNA G-quadruplexes are essential for their functions in vivo and in vitro. Our present study revealed that sequential order of the three G-quadruplex loops, that is, loop transposition, could be a critical factor to determinate the G-quadruplex conformation and consequently improved the catalytic function of G-quadruplex based DNAzyme. In the presence of 100mM K(+), loop transposition induced one of the G-quadruplex isomers which shared identical loops but differed in the sequential order of loops into a hybrid topology while the others into predominately parallel topologies. (1)D NMR spectroscopy and mutation analysis suggested that the hydrogen bonding from loops residues with nucleotides in flanking sequences may be responsible for the stabilization of the different conformations. A well-known DNAzyme consisting of G-quadruplex and hemin (Ferriprotoporphyrin IX chloride) was chosen to test the catalytic function. We found that the loop transposition could enhance the reaction rate obviously by increasing the hemin binding affinity to G-quadruplex. These findings disclose the relations between the loop transposition, G-quadruplex conformation and catalytic function of DNAzyme. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Geometric Structures on Loop and Path Spaces

    Indian Academy of Sciences (India)

    Vicente Muñoz; Francisco Presas

    2010-09-01

    The loop space associated to a Riemannian manifold admits a quasi-symplectic structure (that is, a closed 2-form which is non-degenerate up to a finite-dimensional kernel). We show how to construct a compatible almost-complex structure. Finally conditions to have contact structures on loop spaces are studied.

  8. Holonomy loops, spectral triples and quantum gravity

    DEFF Research Database (Denmark)

    Johannes, Aastrup; Grimstrup, Jesper Møller; Nest, Ryszard

    2009-01-01

    We review the motivation, construction and physical interpretation of a semi-finite spectral triple obtained through a rearrangement of central elements of loop quantum gravity. The triple is based on a countable set of oriented graphs and the algebra consists of generalized holonomy loops...

  9. Newtonian gravity in loop quantum gravity

    OpenAIRE

    Smolin, Lee

    2010-01-01

    We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.

  10. Formation of Chromosomal Domains by Loop Extrusion

    Directory of Open Access Journals (Sweden)

    Geoffrey Fudenberg

    2016-05-01

    Full Text Available Topologically associating domains (TADs are fundamental structural and functional building blocks of human interphase chromosomes, yet the mechanisms of TAD formation remain unclear. Here, we propose that loop extrusion underlies TAD formation. In this process, cis-acting loop-extruding factors, likely cohesins, form progressively larger loops but stall at TAD boundaries due to interactions with boundary proteins, including CTCF. Using polymer simulations, we show that this model produces TADs and finer-scale features of Hi-C data. Each TAD emerges from multiple loops dynamically formed through extrusion, contrary to typical illustrations of single static loops. Loop extrusion both explains diverse experimental observations—including the preferential orientation of CTCF motifs, enrichments of architectural proteins at TAD boundaries, and boundary deletion experiments—and makes specific predictions for the depletion of CTCF versus cohesin. Finally, loop extrusion has potentially far-ranging consequences for processes such as enhancer-promoter interactions, orientation-specific chromosomal looping, and compaction of mitotic chromosomes.

  11. Vacuum Energy Sequestering and Graviton Loops

    CERN Document Server

    Kaloper, Nemanja

    2016-01-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  12. High-Order Frequency-Locked Loops

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In very recent years, some attempts for designing high-order frequency-locked loops (FLLs) have been made. Nevertheless, the advantages and disadvantages of these structures, particularly in comparison with a standard FLL and high-order phase-locked loops (PLLs), are rather unclear. This lack......) as well as a unification between FLLs and PLLs is presented....

  13. Conformal anomaly of super Wilson loop

    Energy Technology Data Exchange (ETDEWEB)

    Belitsky, A.V., E-mail: andrei.belitsky@asu.edu [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States)

    2012-09-11

    Classically supersymmetric Wilson loop on a null polygonal contour possesses all symmetries required to match it onto non-MHV amplitudes in maximally supersymmetric Yang-Mills theory. However, to define it quantum mechanically, one is forced to regularize it since perturbative loop diagrams are not well defined due to presence of ultraviolet divergences stemming from integration in the vicinity of the cusps. A regularization that is adopted by practitioners by allowing one to use spinor helicity formalism, on the one hand, and systematically go to higher orders of perturbation theory is based on a version of dimensional regularization, known as Four-Dimensional Helicity scheme. Recently it was demonstrated that its use for the super Wilson loop at one loop breaks both conformal symmetry and Poincare supersymmetry. Presently, we exhibit the origin for these effects and demonstrate how one can undo this breaking. The phenomenon is alike the one emerging in renormalization group mixing of conformal operators in conformal theories when one uses dimensional regularization. The rotation matrix to the diagonal basis is found by means of computing the anomaly in the Ward identity for the conformal boost. Presently, we apply this ideology to the super Wilson loop. We compute the one-loop conformal anomaly for the super Wilson loop and find that the anomaly depends on its Grassmann coordinates. By subtracting this anomalous contribution from the super Wilson loop we restore its interpretation as a dual description for reduced non-MHV amplitudes which are expressed in terms of superconformal invariants.

  14. Design Principles for Closed Loop Supply Chains

    NARCIS (Netherlands)

    H.R. Krikke (Harold); C.P. Pappis (Costas); G.T. Tsoulfas; J.M. Bloemhof-Ruwaard (Jacqueline)

    2001-01-01

    textabstractIn this paper we study design principles for closed loop supply chains. Closed loop supply chains aim at closing material flows thereby limiting emission and residual waste, but also providing customer service at low cost. We study 'traditional' and 'new' design principles known in the l

  15. Loop approaches to gauge field theory

    NARCIS (Netherlands)

    Loll, R.

    1992-01-01

    Basic mathematical and physical concepts in loop- and path-dependent formulations of Yang-MiIls theory are reviewed and set into correspondence. We point out some problems peculiar to these non-local approaches, in particular those associated with defining structure on various kinds of loop

  16. External Tank CIL Closed Loop Verification System

    Science.gov (United States)

    Hartley, Eugene A., Jr.

    2005-01-01

    Lockheed Martin was requested to develop a closed loop CIL system following the Challenger accident. The system that was developed has proven to be very robust with minimal problems since implementation, having zero escapes in the last 7 years (27 External Tanks). We are currently investigating expansion of the CIL Closed Loop system to include "MI" CILs.

  17. Vacuum Energy Sequestering and Graviton Loops

    OpenAIRE

    Kaloper, Nemanja; Padilla, Antonio

    2016-01-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  18. New Matrix Loop Algebra and Its Application

    Institute of Scientific and Technical Information of China (English)

    DONG Huan-He; XU Yue-Cai

    2008-01-01

    A new matrix Lie algebra and its corresponding Loop algebra are constructed firstly, as its appfication, the multi-component TC equation hierarchy is obtained, then by use of trace identity the Hamiltonian structure of the above system is presented. Finally, the integrable couplings of the obtained system is worked out by the expanding matrix Loop algebra.

  19. Complete renormalization of QCD at five loops

    Science.gov (United States)

    Luthe, Thomas; Maier, Andreas; Marquard, Peter; Schröder, York

    2017-03-01

    We present new analytical five-loop Feynman-gauge results for the anomalous dimensions of ghost field and -vertex, generalizing the known values for SU(3) to a general gauge group. Together with previously published results on the quark mass and -field anomalous dimensions and the Beta function, this completes the 5-loop renormalization program of gauge theories in that gauge.

  20. Newtonian gravity in loop quantum gravity

    OpenAIRE

    Smolin, Lee

    2010-01-01

    We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.

  1. Design Principles for Closed Loop Supply Chains

    NARCIS (Netherlands)

    H.R. Krikke (Harold); C.P. Pappis (Costas); G.T. Tsoulfas; J.M. Bloemhof-Ruwaard (Jacqueline)

    2001-01-01

    textabstractIn this paper we study design principles for closed loop supply chains. Closed loop supply chains aim at closing material flows thereby limiting emission and residual waste, but also providing customer service at low cost. We study 'traditional' and 'new' design principles known in the

  2. Probing loop quantum gravity with evaporating black holes.

    Science.gov (United States)

    Barrau, A; Cailleteau, T; Cao, X; Diaz-Polo, J; Grain, J

    2011-12-16

    This Letter aims at showing that the observation of evaporating black holes should allow the usual Hawking behavior to be distinguished from loop quantum gravity (LQG) expectations. We present a full Monte Carlo simulation of the evaporation in LQG and statistical tests that discriminate between competing models. We conclude that contrarily to what was commonly thought, the discreteness of the area in LQG leads to characteristic features that qualify evaporating black holes as objects that could reveal quantum gravity footprints.

  3. High Level Synthesis for Loop-Based BIST

    Institute of Scientific and Technical Information of China (English)

    李晓维; 张英相

    2000-01-01

    Area and test time are two major overheads encountered during data path high level synthesis for BIST. This paper presents an approach to behavioral synthesis for loop-based BIST. By taking into account the requirements of the BIST scheme during behavioral synthesis processes, an area optimal BIST solution can be obtained. This approach is based on the use of test resources reusability that results in a fewer number of registers being modified to be test registers. This is achieved by incorporating self-testability constraints during register assignment operations. Experimental results on benchmarks are presented to demonstrate the effectiveness of the approach.

  4. Feedback Loop Gains and Feedback Behavior (1996)

    DEFF Research Database (Denmark)

    Kampmann, Christian Erik

    2012-01-01

    Linking feedback loops and system behavior is part of the foundation of system dynamics, yet the lack of formal tools has so far prevented a systematic application of the concept, except for very simple systems. Having such tools at their disposal would be a great help to analysts in understanding...... large, complicated simulation models. The paper applies tools from graph theory formally linking individual feedback loop strengths to the system eigenvalues. The significance of a link or a loop gain and an eigenvalue can be expressed in the eigenvalue elasticity, i.e., the relative change...... of an eigenvalue resulting from a relative change in the gain. The elasticities of individual links and loops may be found through simple matrix operations on the linearized system. Even though the number of feedback loops can grow rapidly with system size, reaching astronomical proportions even for modest systems...

  5. Damped transverse oscillations of interacting coronal loops

    CERN Document Server

    Soler, Roberto

    2015-01-01

    Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations compared to those of an isolated loop. Here we theoretically investigate resonantly damped transverse oscillations of interacting non-uniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. ...

  6. Dynamic Model of Gap Loop for HCW Mill

    Institute of Scientific and Technical Information of China (English)

    YANG Jing-ming; YANG Qiu-xia; CHE Hai-jun; CHANG Ling-fang

    2004-01-01

    The hydraulic automatic gauge control system using gap loop for cold mill was designed. The stiffness of HCW cold mill was defined for gap loop, and the dynamic model of gauge control system for gap loop was built with mechanism analysis. The stiffness for gap loop and the cylinder displacement loop were measured.

  7. Full parabolic trough qualification from prototype to demonstration loop

    Science.gov (United States)

    Janotte, Nicole; Lüpfert, Eckhard; Pottler, Klaus; Schmitz, Mark

    2017-06-01

    On the example of the HelioTrough® collector development the full accompanying and supporting qualification program for large-scale parabolic trough collectors for solar thermal power plants is described from prototype to demonstration loop scale. In the evaluation process the actual state and the optimization potential are assessed. This includes the optical and geometrical performance determined by concentrator shape, deformation, assembly quality and local intercept factor values. Furthermore, its mechanical performance in terms of tracking accuracy and torsional stiffness and its thermal system performance on the basis of the overall thermal output and heat loss are evaluated. Demonstration loop tests deliver results of collector modules statistical slope deviation of 1.9 to 2.6 mrad, intercept factor above 98%, peak optical performance of 81.6% and heat loss coefficients from field tests. The benefit of such a closely monitored development lies in prompt feedback on strengths, weaknesses and potential improvements on the new product at any development stage from first module tests until demonstration loop evaluation. The product developer takes advantage of the achieved technical maturity, already before the implementation in a commercial power plant. The well-understood performance characteristics allow the reduction of safety margins making the new HelioTrough collector competitive from the start.

  8. Direct loop gain and bandwidth measurement of phase-locked loop

    Science.gov (United States)

    Ye, P.; Ren, R.; Kou, Y.; Sun, F.; Hu, J.; Chen, S.; Hou, D.

    2017-08-01

    A simple and robust technique for directly measuring the loop gain and bandwidth of a phase-locked loop (PLL) is proposed. This technique can be used for the real-time measurement of the real loop gain in a closed PLL without breaking its locking state. The agreement of the measured loop gain and theoretical calculations proves the validity of the proposed measurement technique. This technique with a simple configuration can be easily expanded to other phase-locking systems whose loop gain and bandwidth should be measured precisely.

  9. Comparisons of Heat Transfer Performance of a Closed-looped Oscillating Heat Pipe and Closed-looped Oscillating Heat Pipe with Check Valves Heat Exchangers

    Directory of Open Access Journals (Sweden)

    P. Meena

    2008-01-01

    Full Text Available This research was to study the comparisons of heat transfer performance of closed-looped oscillating heat pipe and closed-looped oscillating heat pipe with check valves heat exchangers with R134a, Ethanol and water were used as the working fluids. A set of heat pipe heat exchanger (CLOHP and CLOHP/CV were made of copper tubes in combination of following dimension: 2.03 mm inside diameter: 40 turns, with 20, 10 and 20 cm for evaporator, adiabatic and condenser sections lengths. The working fluid was filled in the tube at the filling ratio of 50%. The evaporator section was given heat by heater while the condenser section was cooled by air. The adiabatic section was properly insulated. In the test operation, it could be concluded as follows. It indicated that the heat transfer performance of closed-looped oscillating heat pipe with check valves heat exchanger better than closed-looped oscillating heat exchanger.

  10. Mechanical comparison of loop and crimp configurations for extracapsular stabilization of the cranial cruciate ligament-deficient stifle.

    Science.gov (United States)

    Aisa, Josep; Calvo, Ignacio; Buckley, Conor T; Kirby, Barbara M

    2015-01-01

    To biomechanically compare different loop and crimp configurations used for extracapsular suture stabilization of the CCL-deficient stifle. In vitro study. Crimped loop constructs of 100 lb Ande type nylon leader line in 7 different configurations comprising single and double loops, single and double crimps, and the interlocking loop configuration. Constructs premade on external skeletal fixator bars 60 mm apart and tested in tension with a custom-made split circular arm mounted on a table-top materials testing machine. Data were derived from force/displacement plots. In "load to failure" test (10/group) constructs were loaded to failure with distraction rates of 10 mm/min; ultimate load, tension at 2 mm elongation and failure were recorded. In "staircase" test (5/group) constructs cycled at 100 N/s from 75 N with incremental increases of 50 N/cycle; ultimate load, maximum tension before elongation at rest over 2 mm and failure were recorded. In "cycling and jumping" test (10/group) 3 of 7 constructs cycled at 100 N/s 100 times from 50 to 100 N, then 5 times from 50 to 600 N; failure and elongation at cycles 1, 50 and 100 and at jumps 1 to 5 recorded. Double-loop double-crimp configurations were statistically superior to all other configurations in ultimate load, and to single-loop and interlocking loop configurations in elongation in "load to failure" and "staircase" tests. In "cycling and jumping" test the interlocking loop configuration specimens elongated significantly more than the others and only in the double-loop double-crimp group did all constructs complete the test. Double-loop double-crimp configurations are mechanically superior to other previously described configurations. © Copyright 2014 by The American College of Veterinary Surgeons.

  11. Cygnus Loop Supernova Blast Wave

    Science.gov (United States)

    1993-01-01

    This is an image of a small portion of the Cygnus Loop supernova remnant, which marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion, occurring about 15,000 years ago. The HST image shows the structure behind the shock waves, allowing astronomers for the first time to directly compare the actual structure of the shock with theoretical model calculations. Besides supernova remnants, these shock models are important in understanding a wide range of astrophysical phenomena, from winds in newly-formed stars to cataclysmic stellar outbursts. The supernova blast is slamming into tenuous clouds of insterstellar gas. This collision heats and compresses the gas, causing it to glow. The shock thus acts as a searchlight revealing the structure of the interstellar medium. The detailed HST image shows the blast wave overrunning dense clumps of gas, which despite HST's high resolution, cannot be resolved. This means that the clumps of gas must be small enough to fit inside our solar system, making them relatively small structures by interstellar standards. A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova; this interstellar 'bullet' traveling over three million miles per hour (5 million kilometres) is just catching up with the shock front, which has slowed down by ploughing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full Moon), located in the northern constellation, Cygnus the Swan. The supernova remnant is within the plane of our Milky Way galaxy and is 2,600 light-years away. The photo is a combination of separate images taken in three colors, oxygen atoms (blue) emit light at temperatures of 30,000 to 60,000 degrees Celsius (50,000 to 100,000 degrees Farenheit). Hydrogen atoms (green) arise throughout the region of shocked gas. Sulfur atoms (red) form when the gas cools to

  12. Loop Staggering,Loop Compacting:Restructuring Techniques for Thrashing Problem

    Institute of Scientific and Technical Information of China (English)

    金国华; 杨学军; 等

    1993-01-01

    Parallel loops account for the greatest amount of parallelism in numerical programs.Executing nested loops in parallel wit low run-time overhead is thus very important for achieving high performance in paralleo processing systems.However,in parallel processing systems with caches of local memories in memory hierarchies,“thrashing problemmay” may arise when data move back and forth frequently between the caches or local memories in different processors.The techniques associated with parallel compiler to solve the problem are not completely developed.In this paper,we present two restructuring techniques called loopg staggering,loop staggering and compacting,with which we can not only eliminate the cache or local memory thrashing phemomena significantly,but also exploit the potential parallelism existing in outer serial loop.Loop staggering benefits the dynamic loop scheduling strategies,whereas loop staggering and compacting is good for static loop scheduling strategies,Our method especially benefits parallel programs,in which a parallel loop is enclosed by a serial loop and array elements are repeatedly used in the different iterations of the parallel loop.

  13. Cardiovascular simulator improvement: pressure versus volume loop assessment.

    Science.gov (United States)

    Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Leme, Juliana; Legendre, Daniel; Bock, Eduardo; Lucchi, Julio Cesar

    2011-05-01

    This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance. In many heart diseases, the stroke volume decreases because of low heart contractility. This pathological situation must be simulated by the PCS in order to evaluate the assistance provided by a ventricular assist device (VAD). The PCS system is automatically controlled by a computer and is an auxiliary tool for VAD control strategies development. This PCS system is according to a Windkessel model where lumped parameters are used for cardiovascular system analysis. Peripheral resistance, arteries compliance, and fluid inertance are simulated. The simulator has an actuator with a roller screw and brushless direct current motor, and the stroke volume is regulated by the actuator displacement. Internal pressure and volume measurements are monitored to obtain the PxV loop. Left chamber internal pressure is directly obtained by pressure transducer; however, internal volume has been obtained indirectly by using a linear variable differential transformer, which senses the diaphragm displacement. Correlations between the internal volume and diaphragm position are made. LabVIEW integrates these signals and shows the pressure versus internal volume loop. The results that have been obtained from the PCS system show PxV loops at different ventricle elastances, making possible the simulation of pathological situations. A preliminary test with a pulsatile VAD attached to PCS system was made.

  14. Bending of the looping heart: differential growth revisited.

    Science.gov (United States)

    Shi, Yunfei; Yao, Jiang; Xu, Gang; Taber, Larry A

    2014-08-01

    In the early embryo, the primitive heart tube (HT) undergoes the morphogenetic process of c-looping as it bends and twists into a c-shaped tube. Despite intensive study for nearly a century, the physical forces that drive looping remain poorly understood. This is especially true for the bending component, which is the focus of this paper. For decades, experimental measurements of mitotic rates had seemingly eliminated differential growth as the cause of HT bending, as it has commonly been thought that the heart grows almost exclusively via hyperplasia before birth and hypertrophy after birth. Recently published data, however, suggests that hypertrophic growth may play a role in looping. To test this idea, we developed finite-element models that include regionally measured changes in myocardial volume over the HT. First, models based on idealized cylindrical geometry were used to simulate the bending process in isolated hearts, which bend without the complicating effects of external loads. With the number of free parameters in the model reduced to the extent possible, stress and strain distributions were compared to those measured in embryonic chick hearts that were isolated and cultured for 24 h. The results show that differential growth alone yields results that agree reasonably well with the trends in our data, but adding active changes in myocardial cell shape provides closer quantitative agreement with stress measurements. Next, the estimated parameters were extrapolated to a model based on realistic 3D geometry reconstructed from images of an actual chick heart. This model yields similar results and captures quite well the basic morphology of the looped heart. Overall, our study suggests that differential hypertrophic growth in the myocardium (MY) is the primary cause of the bending component of c-looping, with other mechanisms possibly playing lesser roles.

  15. Predicting loop-helix tertiary structural contacts in RNA pseudoknots.

    Science.gov (United States)

    Cao, Song; Giedroc, David P; Chen, Shi-Jie

    2010-03-01

    Tertiary interactions between loops and helical stems play critical roles in the biological function of many RNA pseudoknots. However, quantitative predictions for RNA tertiary interactions remain elusive. Here we report a statistical mechanical model for the prediction of noncanonical loop-stem base-pairing interactions in RNA pseudoknots. Central to the model is the evaluation of the conformational entropy for the pseudoknotted folds with defined loop-stem tertiary structural contacts. We develop an RNA virtual bond-based conformational model (Vfold model), which permits a rigorous computation of the conformational entropy for a given fold that contains loop-stem tertiary contacts. With the entropy parameters predicted from the Vfold model and the energy parameters for the tertiary contacts as inserted parameters, we can then predict the RNA folding thermodynamics, from which we can extract the tertiary contact thermodynamic parameters from theory-experimental comparisons. These comparisons reveal a contact enthalpy (DeltaH) of -14 kcal/mol and a contact entropy (DeltaS) of -38 cal/mol/K for a protonated C(+)*(G-C) base triple at pH 7.0, and (DeltaH = -7 kcal/mol, DeltaS = -19 cal/mol/K) for an unprotonated base triple. Tests of the model for a series of pseudoknots show good theory-experiment agreement. Based on the extracted energy parameters for the tertiary structural contacts, the model enables predictions for the structure, stability, and folding pathways for RNA pseudoknots with known or postulated loop-stem tertiary contacts from the nucleotide sequence alone.

  16. Functional characterization of antibodies against Neisseria gonorrhoeae opacity protein loops.

    Directory of Open Access Journals (Sweden)

    Jessica G Cole

    Full Text Available BACKGROUND: The development of a gonorrhea vaccine is challenged by the lack of correlates of protection. The antigenically variable neisserial opacity (Opa proteins are expressed during infection and have a semivariable (SV and highly conserved (4L loop that could be targeted in a vaccine. Here we compared antibodies to linear (Ab(linear and cyclic (Ab(cyclic peptides that correspond to the SV and 4L loops and selected hypervariable (HV(2 loops for surface-binding and protective activity in vitro and in vivo. METHODS/FINDINGS: Ab(SV cyclic bound a greater number of different Opa variants than Ab(SV linear, including variants that differed by seven amino acids. Antibodies to the 4L peptide did not bind Opa-expressing bacteria. Ab(SV (cyclic and Ab(HV2 (cyclic, but not Ab(SV (linear or Ab(HV2 linear agglutinated homologous Opa variants, and Ab(HV2BD (cyclic but not Ab(HV2BD (linear blocked the association of OpaB variants with human endocervical cells. Only Ab(HV2BD (linear were bactericidal against the serum resistant parent strain. Consistent with host restrictions in the complement cascade, the bactericidal activity of Ab(HV2BD (linear was increased 8-fold when rabbit complement was used. None of the antibodies was protective when administered vaginally to mice. Antibody duration in the vagina was short-lived, however, with <50% of the antibodies recovered 3 hrs post-administration. CONCLUSIONS: We conclude that an SV loop-specific cyclic peptide can be used to induce antibodies that recognize a broad spectrum of antigenically distinct Opa variants and have agglutination abilities. HV(2 loop-specific cyclic peptides elicited antibodies with agglutination and adherence blocking abilities. The use of human complement when testing the bactericidal activity of vaccine-induced antibodies against serum resistant gonococci is also important.

  17. The adaptive-loop-gain adaptive-scale CLEAN deconvolution of radio interferometric images

    CERN Document Server

    Zhang, L; Liu, X

    2016-01-01

    CLEAN algorithms are a class of deconvolution solvers which are widely used to remove the effect of the telescope Point Spread Function (PSF). Loop gain is one important parameter in CLEAN algorithms. Currently the parameter is fixed during deconvolution, which restricts the performance of CLEAN algorithms. In this paper, we propose a new deconvolution algorithm with an adaptive loop gain scheme, which is referred to as the adaptive-loop-gain adaptivescale CLEAN (Algas-Clean) algorithm. The test results show that the new algorithm can give a more accurate model with faster convergence.

  18. Hypnosis closed loop TCI systems in outpatient surgery.

    Science.gov (United States)

    Ramos-Luengo, A; Asensio-Merino, F

    Determine the influence of general anaesthesia with closed-loop systems in the results of outpatient varicose vein surgery. Retrospective observational study including data from 270 outpatients between 2014 and 2015. The patients were divided into 2 groups according to the type of general anaesthesia used. The CL Group included patients who received propofol in closed-loop guided by BIS and remifentanil using TCI, and the C Group received non-closed-loop anaesthesia. Age, sex, surgical time, discharge time and failure of outpatient surgery were recorded. Quantitative data were checked for normal distribution by the method of Kolmogorov-Smirnov-Lilliefors. Differences between groups were analysed by a Student-t-test or Mann-Whitney-Wilcoxon test, depending on their distribution. Categorical data were analysed by a Chi-squared test. We used Kaplan-Meier estimator and the effect size (calculated by Cohen's d) to study the discharge time. Statistical analysis was performed using R 3.2.3 binary for Mac OS X 10.9. There were no significant differences in age, sex and surgical time and failure of outpatient surgery. Discharge time was different in both groups: 200 (100) vs. 180 (82.5) minutes, C Group and CL Group, respectively (data are median and interquartile rank); P=.005. The use of closed-loop devices for the hypnotic component of anaesthesia hastens discharge time. However, for this effect to be clinically significant, some improvements still need to be made in our outpatient surgery units. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Loops in exceptional field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bossard, Guillaume [Centre de Physique Théorique, Ecole Polytechnique, CNRS, Université Paris-Saclay,91128 Palaiseau cedex (France); Kleinschmidt, Axel [Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut),Am Mühlenberg 1, DE-14476 Potsdam (Germany); International Solvay Institutes,ULB-Campus Plaine CP231, BE-1050 Brussels (Belgium)

    2016-01-27

    We study certain four-graviton amplitudes in exceptional field theory in dimensions D≥4 up to two loops. As the formulation is manifestly invariant under the U-duality group E{sub 11−D}(ℤ), our resulting expressions can be expressed in terms of automorphic forms. In the low energy expansion, we find terms in the M-theory effective action of type R{sup 4}, ∇{sup 4}R{sup 4} and ∇{sup 6}R{sup 4} with automorphic coefficient functions in agreement with independent derivations from string theory. This provides in particular an explicit integral formula for the exact string theory ∇{sup 6}R{sup 4} threshold function. We exhibit moreover that the usual supergravity logarithmic divergences cancel out in the full exceptional field theory amplitude, within an appropriately defined dimensional regularisation scheme. We also comment on terms of higher derivative order and the role of the section constraint for possible counterterms.

  20. Pasta phases in core-collapse supernova matter

    Science.gov (United States)

    Pais, Helena; Chiacchiera, Silvia; Providência, Constança

    2016-04-01

    The pasta phase in core-collapse supernova matter (finite temperatures and fixed proton fractions) is studied within relativistic mean field models. Three different calculations are used for comparison, the Thomas-Fermi (TF), the Coexisting Phases (CP) and the Compressible Liquid Drop (CLD) approximations. The effects of including light clusters in nuclear matter and the densities at which the transitions between pasta configurations and to uniform matter occur are also investigated. The free energy and pressure, in the space of particle number densities and temperatures expected to cover the pasta region, are calculated. Finally, a comparison with a finite temperature Skyrme-Hartree-Fock calculation is drawn.

  1. A new delay line loops shrinking time-to-digital converter in low-cost FPGA

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie, E-mail: zhangjie071063@163.com [State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, CAS, Wuhan, China, 430077 (China); University of Chinese Academy of Sciences, Beijing, China, 100049 (China); Zhou, Dongming [State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, CAS, Wuhan, China, 430077 (China)

    2015-01-21

    The article provides the design and test results of a new time-to-digital converter (TDC) based on delay line loops shrinking method and implemented in a low-cost field programmable gate array (FPGA) device. A technique that achieves high resolution with low cost and flexibility is presented. The technique is based on two delay line loops which are used to directly shrink the measured time interval in the designed TDC, and the resolution is dependent on the difference between the entire delay times of the two delay line loops. In order to realize high resolution and eliminate temperature influence, the two delay line loops consist of the same delay cells with the same number. A delay-locked loop (DLL) is used to stabilize the resolution against process variations and ambient conditions. Meanwhile, one method is used to accurately evaluate the resolution of the implemented TDC. The converter has been implemented in a general-propose FPGA device (Actel SmartFusion A2F200M3). A single shot resolution of the implemented converter is 63.3 ps and the measurement standard deviation is about 61.7 ps within the measurement range of 5 ns. - Highlights: • We provide a new FPGA-integrated time-to-digital converter based on delay line loops method which used two delay line loops to directly shrink time intervals with only rising edges. • The two delay line loops consist of the same delay cells with the same number and symmetrical structure. • The resolution is dependent on the difference between the entire delays of the two delay line loops. • We use delay-locked loop to stabilize the resolution against temperature and supply voltage.

  2. Analysis of first and second order binary quantized digital phase-locked loops for ideal and white Gaussian noise inputs

    Science.gov (United States)

    Blasche, P. R.

    1980-01-01

    Specific configurations of first and second order all digital phase locked loops are analyzed for both ideal and additive white gaussian noise inputs. In addition, a design for a hardware digital phase locked loop capable of either first or second order operation is presented along with appropriate experimental data obtained from testing of the hardware loop. All parameters chosen for the analysis and the design of the digital phase locked loop are consistent with an application to an Omega navigation receiver although neither the analysis nor the design are limited to this application.

  3. Can flow-volume loops be used to diagnose exercise induced laryngeal obstructions?

    DEFF Research Database (Denmark)

    Christensen, Pernille M; Maltbæk, Niels; Jørgensen, Inger M

    2013-01-01

    BACKGROUND: Pre- and post-exercise flow-volume loops are often recommended as an easy non-invasive method for diagnosing or excluding exercise-induced laryngeal obstructions in patients with exercise-related respiratory symptoms. However, at present there is no evidence for this recommendation....... AIMS: To compare physician evaluated pre- and post-exercise flow-volume loops and flow data with laryngoscopic findings during exercise. METHODS: Data from 100 consecutive exercise tests with continuous laryngoscopy during the test were analysed. Laryngoscopic images were compared...... with the corresponding pre- and post-exercise flow-volume loops assessed by four separate physicians and with data from the loops (forced inspiratory flow (FIF) at 25% vs. FIF at 75% of forced inspiratory vital capacity (FIVC), forced expiratory flow at 50% of forced expiratory volume vs. FIF at 50% of FIVC, and FIVC vs...

  4. Paleomagnetism of the Neoproterozoic Blekinge-Dalarna Dolerites in Western Sweden and Implications of the Sveconorwegian Loop(s)

    Science.gov (United States)

    Gong, Z.; Evans, D. A.; Elming, S. A.

    2016-12-01

    Laurentia and Baltica are regarded to be juxtaposed at the core of the supercontinent Rodinia during Early Neoproterozoic. This contention is supported by the similar apparent polar wander paths (APWPs) of Laurentia and Baltica, known as the Grenville and the Sveconorwegian loops, respectively. Despite the debates of the age and shape of the Grenville loop, the Sveconorwegian loop has uncertainties as well. Paleomagnetic studies from Baltica show two distinct remanence directions at ca. 950 Ma: one is steep and upwards (A-type) and another is shallow and bipolar (B-type). The fidelity of B-type remanence is supported by the new key-pole from the 935 ± 5 Ma Blekinge-Dalarna dolerites (BDD) in western Sweden. But A-type remanence, less common, is also observed in the BDD dykes. Some studies attribute A-type remanence to remagnetization without clear evidence. If A-type remanence is primary, this would suggest a large APWP excursion of Baltica within a very short duration, analogous to the mid-Ediacaran situation of Laurentia that has been explained by different hypotheses such as true polar wander, unusual geomagnetic configuration or rapid plate motions. Therefore, we conducted a more detailed paleomagnetic study of the BDD dykes that cover an area of 10,000 km2. We propose a combined geochemical and magnetic fabric study to compare BDD dykes' signatures with published results to aid field identification. Thermal demagnetization is conducted and the fidelity of the remanence is examined by rigorous baked contact tests in different host rocks. Dykes with primary remanence will be radiometrically dated to constrain the age of the remanence. This study should have wide implications, in particular the configuration of Sveconorwegian loop(s) in Early Neoproterozoic time, the paleogeographic connection between Laurentia and Baltica in Rodinia, as well as the geodynamics in Earth's deep interior.

  5. Analysis and improvement of missile three-loop autopilots

    Institute of Scientific and Technical Information of China (English)

    Lin Defu; Fan Junfang; Qi Zaikang; Mou Yu

    2009-01-01

    characteristics from a two-loop autopilot with PI compensator.Both the two-loop and three-loop topologies can stabilize a static unstable missile.However,the finite actuator resource is the crucial factor dominating autopilot function.

  6. Mitotic chromosome compaction via active loop extrusion

    Science.gov (United States)

    Goloborodko, Anton; Imakaev, Maxim; Marko, John; Mirny, Leonid; MIT-Northwestern Team

    During cell division, two copies of each chromosome are segregated from each other and compacted more than hundred-fold into the canonical X-shaped structures. According to earlier microscopic observations and the recent Hi-C study, chromosomes are compacted into arrays of consecutive loops of ~100 kilobases. Mechanisms that lead to formation of such loop arrays are largely unknown. Here we propose that, during cell division, chromosomes can be compacted by enzymes that extrude loops on chromatin fibers. First, we use computer simulations and analytical modeling to show that a system of loop-extruding enzymes on a chromatin fiber self-organizes into an array of consecutive dynamic loops. Second, we model the process of loop extrusion in 3D and show that, coupled with the topo II strand-passing activity, it leads to robust compaction and segregation of sister chromatids. This mechanism of chromosomal condensation and segregation does not require additional proteins or specific DNA markup and is robust against variations in the number and properties of such loop extruding enzymes. Work at NU was supported by the NSF through Grants DMR-1206868 and MCB-1022117, and by the NIH through Grants GM105847 and CA193419. Work at MIT was supported by the NIH through Grants GM114190 R01HG003143.

  7. Thermal energy storage test facility

    Science.gov (United States)

    Ternes, M. P.

    1981-03-01

    Two loops making up the facility, using either air or liquid as the thermal transport fluid, are described. These loops will be capable of cycling residential-size thermal energy storage units through conditions simulating solar or off-peak electricity applications to evaluate the unit's performance. Construction of the liquid cycling loop was completed, and testing of thermal stratification techniques for hot and cold water is reported.

  8. A computerized loop based approach for identification of isomorphism and type of mobility in planar kinematic chains

    Indian Academy of Sciences (India)

    Manoj K Lohumi; Aas Mohammad; Irshad A Khan

    2015-04-01

    Some new invariants like chain string, link identification string, loop participation of joint frequency string and loop size frequency string of simple jointed kinematic chains are presented. The first step of the proposed method is to identify all possible loops of a kinematic chain and then these new invariants are developed. A modified loop-joint approach is proposed in this work as compared to the previous work in literature where loop-link matrix is formulated to search all the loops present in a kinematic chain. A computer program has been developed for formulating loop-joint matrix of kinematic chain and its all invariants. This method takes into consideration all the loops present, associated joints and links and is able to test isomorphism among kinematic chains and their inversions and also to detect type of mobility of multi degree of freedom kinematic chains. The proposed method is successfully tested for all kinematic chains upto five independent loops having any number of degree of freedom and no counter example is found. The detailed results of 9-link, M = 2 (mobility) and 10 link, M = 3 kinematic chains are provided with five types of mobility and results are in accordance with the results published in literature. The method is also explained with the help of some complex examples and presented in this paper.

  9. Remarks on correlators of Polyakov Loops

    CERN Document Server

    Neuberger, Herbert

    2013-01-01

    Polyakov loop eigenvalues and their N-dependence are studied in 2 and 4 dimensional SU(N) YM theory. The connected correlation function of the single eigenvalue distributions of two separated Polyakov loops in 2D YM is calculated and is found to have a structure differing from the one of corresponding hermitian random matrix ensembles. No large $N$ non-analyticities are found for two point functions in the confining regime. Suggestions are made for situations in which large-N phase transitions involving Polyakov loops might occur.

  10. Wilson Loop Form Factors: A New Duality

    OpenAIRE

    Chicherin, Dmitry; Heslop, Paul; Korchemsky, Gregory P.; Sokatchev, Emery

    2016-01-01

    We find a new duality for form factors of lightlike Wilson loops in planar $\\mathcal N=4$ super-Yang-Mills theory. The duality maps a form factor involving an $n$-sided lightlike polygonal super-Wilson loop together with $m$ external on-shell states, to the same type of object but with the edges of the Wilson loop and the external states swapping roles. This relation can essentially be seen graphically in Lorentz harmonic chiral (LHC) superspace where it is equivalent to planar graph duality....

  11. Parallel Digital Phase-Locked Loops

    Science.gov (United States)

    Sadr, Ramin; Shah, Biren N.; Hinedi, Sami M.

    1995-01-01

    Wide-band microwave receivers of proposed type include digital phase-locked loops in which band-pass filtering and down-conversion of input signals implemented by banks of multirate digital filters operating in parallel. Called "parallel digital phase-locked loops" to distinguish them from other digital phase-locked loops. Systems conceived as cost-effective solution to problem of filtering signals at high sampling rates needed to accommodate wide input frequency bands. Each of M filters process 1/M of spectrum of signal.

  12. Boost converter with combined control loop for a stand-alone photovoltaic battery charge system

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Knott, Arnold; Thomsen, Ole Cornelius

    2013-01-01

    The converter control scheme plays an important role in the performance of maximum power point tracking (MPPT) algorithms. In this paper, an input voltage control with double loop for a stand-alone photovoltaic system is designed and tested. The inner current control loop with high crossover...... is linearized at the maximum power point (MPP) and at the voltage and current source regions. A settling time under 1 ms is obtained which allows fast MPP tracking implementation....

  13. $\\gamma\\gamma$ \\to $\\pi\\pi\\pi$ to one loop in chiral perturbation theory

    CERN Document Server

    Talavera, P; Bijnens, J; Bramon, A; Cornet, F

    1995-01-01

    The \\gamma\\gamma \\to \\pi^0 \\pi^0 \\pi^0 and \\gamma\\gamma \\to \\pi^+ \\pi^- \\pi^0 amplitudes are discussed in the general context of Chiral Perturbation Theory (ChPT) to O(p^6). Chiral loops are found to play a major role. This makes these processes a good test of ChPT, mainly in its anomalous sector. We correct earlier numerical results at tree level and determine the one-loop results as well.

  14. Boost converter with combined control loop for a stand-alone photovoltaic battery charge system

    OpenAIRE

    Mira Albert, Maria del Carmen; Knott, Arnold; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    The converter control scheme plays an important role in the performance of maximum power point tracking (MPPT) algorithms. In this paper, an input voltage control with double loop for a stand-alone photovoltaic system is designed and tested. The inner current control loop with high crossover frequency avoids perturbations in the load being propagated to the photovoltaic panel and thus deviating the operating point. Linearization of the photovoltaic panel and converter state-space modeling is ...

  15. Twist-three at five loops, Bethe Ansatz and wrapping

    CERN Document Server

    Beccaria, M; Lukowski, T; Zieme, S

    2009-01-01

    We present a formula for the five-loop anomalous dimension of N=4 SYM twist-three operators in the sl(2) sector. We obtain its asymptotic part from the Bethe Ansatz and finite volume corrections from the generalized Luescher formalism, considering scattering processes of spin chain magnons with virtual particles that travel along the cylinder. The complete result respects the expected large spin scaling properties and passes non-trivial tests including reciprocity constraints. We analyze the pole structure and find agreement with a conjectured resummation formula. In analogy with the twist-two anomalous dimension at four-loops, wrapping effects are of order log^2 M/M^2 for large values of the spin.

  16. Protein loop modeling using a new hybrid energy function and its application to modeling in inaccurate structural environments.

    Directory of Open Access Journals (Sweden)

    Hahnbeom Park

    Full Text Available Protein loop modeling is a tool for predicting protein local structures of particular interest, providing opportunities for applications involving protein structure prediction and de novo protein design. Until recently, the majority of loop modeling methods have been developed and tested by reconstructing loops in frameworks of experimentally resolved structures. In many practical applications, however, the protein loops to be modeled are located in inaccurate structural environments. These include loops in model structures, low-resolution experimental structures, or experimental structures of different functional forms. Accordingly, discrepancies in the accuracy of the structural environment assumed in development of the method and that in practical applications present additional challenges to modern loop modeling methods. This study demonstrates a new strategy for employing a hybrid energy function combining physics-based and knowledge-based components to help tackle this challenge. The hybrid energy function is designed to combine the strengths of each energy component, simultaneously maintaining accurate loop structure prediction in a high-resolution framework structure and tolerating minor environmental errors in low-resolution structures. A loop modeling method based on global optimization of this new energy function is tested on loop targets situated in different levels of environmental errors, ranging from experimental structures to structures perturbed in backbone as well as side chains and template-based model structures. The new method performs comparably to force field-based approaches in loop reconstruction in crystal structures and better in loop prediction in inaccurate framework structures. This result suggests that higher-accuracy predictions would be possible for a broader range of applications. The web server for this method is available at http://galaxy.seoklab.org/loop with the PS2 option for the scoring function.

  17. Eigenvalue distributions of Wilson loops

    Energy Technology Data Exchange (ETDEWEB)

    Lohmayer, Robert

    2010-07-01

    In the first part of this thesis, we focus on the distribution of the eigenvalues of the unitary Wilson loop matrix in the two-dimensional case at arbitrary finite N. To characterize the distribution of the eigenvalues, we introduce three density functions (the ''symmetric'', the ''antisymmetric'', and the ''true'' eigenvalue density) which differ at finite N but possess the same infinite-N limit, exhibiting the Durhuus-Olesen phase transition. Using expansions of determinants and inverse determinants in characters of totally symmetric or totally antisymmetric representations of SU(N), the densities at finite N can be expressed in terms of simple sums involving only dimensions and quadratic Casimir invariants of certain irreducible representations of SU(N), allowing for a numerical computation of the densities at arbitrary N to any desired accuracy. We find that the true eigenvalue density, adding N oscillations to the monotonic symmetric density, is in some sense intermediate between the symmetric and the antisymmetric density, which in turn is given by a sum of N delta peaks located at the zeros of the average of the characteristic polynomial. Furthermore, we show that the dependence on N can be made explicit by deriving integral representations for the resolvents associated to the three eigenvalue densities. Using saddle-point approximations, we confirm that all three densities reduce to the Durhuus-Olesen result in the infinite-N limit. In the second part, we study an exponential form of the multiplicative random complex matrix model introduced by Gudowska-Nowak et al. Varying a parameter which can be identified with the area of the Wilson loop in the unitary case, the region of non-vanishing eigenvalue density of the N-dimensional complex product matrix undergoes a topological change at a transition point in the infinite-N limit. We study the transition by a detailed analysis of the average of the

  18. Hydride formation in core-shell alloyed metal nanoparticles

    Science.gov (United States)

    Zhdanov, Vladimir P.

    2016-07-01

    The model and analysis presented are focused on hydride formation in nanoparticles with a Pd shell and a core formed by another metal. The arrangement of metal atoms is assumed to be coherent (no dislocations). The lattice strain distribution, elastic energy, and chemical potential of hydrogen atoms are scrutinized. The slope of the chemical potential (as a function of hydrogen uptake) is demonstrated to decrease with increasing the core volume, and accordingly the critical temperature for hydride formation and the corresponding hysteresis loops are predicted to decrease as well.

  19. Integrated Evaluation of Closed Loop Air Revitalization System Components

    Science.gov (United States)

    Murdock, K.

    2010-01-01

    NASA s vision and mission statements include an emphasis on human exploration of space, which requires environmental control and life support technologies. This Contractor Report (CR) describes the development and evaluation of an Air Revitalization System, modeling and simulation of the components, and integrated hardware testing with the goal of better understanding the inherent capabilities and limitations of this closed loop system. Major components integrated and tested included a 4-Bed Modular Sieve, Mechanical Compressor Engineering Development Unit, Temperature Swing Adsorption Compressor, and a Sabatier Engineering and Development Unit. The requisite methodolgy and technical results are contained in this CR.

  20. Evaluation of tensile strength of different configurations of orthodontic retraction loops for obtaining optimized forces.

    Science.gov (United States)

    Blaya, Miceli Beck Guimaraes; Westphalen, Graziela Henriques; Guimaraes, Magali Beck; Hirakata, Luciana Mayumi

    2009-01-01

    The aim of this study was to analyze the mechanical behavior of different orthodontic retraction loops. Two designs of orthodontic loops for closing space were analyzed: teardrop-shaped (T) and circle-shaped loop (C), of two different heights (6 and 8 mm), and two types of orthodontic wires (stainless steel - 0.19' x 0.25'; TMA - titanium molybdenum alloy - 0.016' x 0.016'). The sample consisted of 80 loops, divided into 8 groups determined by the combination shape/height/type of wire, which were submitted to tensile testing at a speed of 2 mm/min., to measure the quantity of force generated when activated in the interval of 0.75 mm and 2.25 mm. The results were submitted to the ANOVA and Tukey statistical tests to compare the groups, and the Student's-t test to compare the means of two groups. Statistically higher values were observed for the size 6 mm, circle shape and stainless steel composition. The group "teardrop-8 mm-TMA" together with the group "circle-8 mm-TMA" presented the lowest mean value, differing statistically from all of the other groups. It was concluded that the alloy of the wire and the height of the loop would be more important than the loop design.