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1

Permeability-porosity relationship for compaction of a low-permeability creeping material : Experimental evaluation using a single transient test  

NASA Astrophysics Data System (ADS)

It is well-known that there is no unique permeability-porosity relationship that can be applied to all porous materials. For a given evolution process that changes both permeability and porosity of a porous material, for example elastic or plastic compaction, microcracking or chemical alteration, it is usually assumed that there is an empirical relationship in the form of a power-law or exponential relationship between these parameters. The coefficients of these empirical relationships depend strongly on the properties of the material and of the evolution process. For the case of the power-law permeability-porosity relationship, a review of the literature shows that the exponent of this relation may be integer or non-integer, constant or variable, and the reported values of exponent vary between 1.1 and 25.4 for different materials and evolution processes, but no clear correlation between the exponenet and the petrophysical properties could be found. This wide variability of the permeability-porosity relationship highlights the necessity of experimental evaluation of this relationship for each material and evolution process. An experimental method is presented for the evaluation of a permeability-porosity relationship in a low-permeability porous material using the results of a single transient test. This method accounts for both elastic and non-elastic deformations of the sample during the test and is applied to a hardened class G oil well cement paste. An initial hydrostatic undrained loading is applied to the sample which generates an excess pore pressure, related to the applied hydrostatic stress by the Skempton coefficient of the material. The generated excess pore pressure is then released at one end of the sample while monitoring the pore pressure at the other end and the radial strain in the middle of the sample during the dissipation of the pore pressure. These measurements are back analysed using a finite-difference numerical scheme to evaluate the permeability and its evolution with porosity change. The stress-dependent character of the poroelastic parameters of the hardened cement paste (Ghabezloo et al., 2008) and also the creep of the material during the test add some particular aspects to the back-analysis, which makes this problem different from the classical solutions of transient permeability evaluation tests. The effect of creep of the sample during the test on the measured pore pressure and volume change is taken into account in the analysis. This approach permits to calibrate a power law permeability-porosity relationship for the tested hardened cement paste and also two parameters of a viscoelastic model for the creep of the material. The porosity sensitivity exponent of the power-law is evaluated equal to 11 and is shown to be mostly independent of the stress level and of the creep strains. The proposed method can be applied to different low permeability porous materials and for the case of non-creeping materials, the same type of analysis can be used to calibrate either a permeability-porosity or a permeability-effective stress relationship for the compaction of the tested material using a single transient test. References: 1.Ghabezloo S., Sulem J., Saint-Marc, J. (2008) Evaluation of a permeability-porosity relationship in a low permeability creeping material using a single transient test. Int J Rock Mech Min Sci, in press, DOI 10.1016/j.ijrmms.2008.10.003. 2.Ghabezloo, S., Sulem, J., Guédon, S., Martineau, F., Saint-Marc, J. (2008) Poromechanical behaviour of hardened cement paste under isotropic loading. Cement and Concrete Research, 38(12), 1424-1437.

Ghabezloo, S.; Sulem, J.; Saint-Marc, J.

2009-04-01

2

Single-Event Transient Testing of Low Dropout PNP Series Linear Voltage Regulators  

NASA Technical Reports Server (NTRS)

As demand for high-speed, on-board, digital-processing integrated circuits on spacecraft increases (field-programmable gate arrays and digital signal processors in particular), the need for the next generation point-of-load (POL) regulator becomes a prominent design issue. Shrinking process nodes have resulted in core rails dropping to values close to 1.0 V, drastically reducing margin to standard switching converters or regulators that power digital ICs. The goal of this task is to perform SET characterization of several commercial POL converters, and provide a discussion of the impact of these results to state-of-the-art digital processing IC through laser and heavy ion testing

Adell, Philippe; Allen, Gregory

2013-01-01

3

Single Event Transients in Low Voltage Dropout (LVDO) Voltage Regulators  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews the use of Low Voltage Dropout (LVDO) Voltage Regulators in environments where heavy ion induced Single Event Transients are a concern to the designers.Included in the presentation are results of tests of voltage regulators.

LaBel, K.; Karsh, J.; Pursley, S.; Kleyner, I.; Katz, R.; Poivey, C.; Kim, H.; Seidleck, C.

2006-01-01

4

Transient Pressure Test Article Test Program  

NASA Technical Reports Server (NTRS)

The Transient Pressure Test Article (TPTA) test program is being conducted at a new test facility located in the East Test Area at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This facility, along with the special test equipment (STE) required for facility support, was constructed specifically to test and verify the sealing capability of the Redesigned Solid Rocket Motor (RSRM) field, igniter, and nozzle joints. The test article consists of full scale RSRM hardware loaded with inert propellant and assembled in a short stack configuration. The TPTA is pressurized by igniting a propellant cartridge capable of inducing a pressure rise rate which stimulates the ignition transient that occurs during launch. Dynamic loads are applied during the pressure cycle to simulate external tank attach (ETA) strut loads present on the ETA ring. Sealing ability of the redesigned joints is evaluated under joint movement conditions produced by these combined loads since joint sealing ability depends on seal resilience velocity being greater than gap opening velocity. Also, maximum flight dynamic loads are applied to the test article which is either pressurized to 600 psia using gaseous nitrogen (GN2) or applied to the test article as the pressure decays inside the test article on the down cycle after the ignition transient cycle. This new test facility is examined with respect to its capabilities. In addition, both the topic of test effectiveness versus space vehicle flight performance and new aerospace test techniques, as well as a comparison between the old SRM design and the RSRM are presented.

Vibbart, Charles M.

1989-01-01

5

Single-Event Transients in Voltage Regulators  

NASA Technical Reports Server (NTRS)

Single-event transients are investigated for two voltage regulator circuits that are widely used in space. A circuit-level model is developed that can be used to determine how transients are affected by different circuit application conditions. Internal protection circuits-which are affected by load as well as internal thermal effects-can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. Although conventional output transients can be reduced by adding load capacitance, that approach is ineffective for dropouts from protection circuitry.

Johnston, Allan H.; Miyahira, Tetsuo F.; Irom, F.; Laird, Jamie S.

2006-01-01

6

Columbia University Flow Instability Experimental Program, Volume 13: Single annulus transient test program data tables, Part 2  

SciTech Connect

This report is one of a series of reports which document the flow instability testing conducted by Columbia University during 1989 through 1992. This testing was completed as part of AX1811457. This report volume provides a hardcopy version of the thirty-four electronic media files: SA0914(A-H).DAT, SAT0609(A-N).DAT, SAT0612(A-O).DAT.

Coutts, D.A.

1993-09-01

7

Single-Event Transients in Bipolar Linear Integrated Circuits  

Microsoft Academic Search

Single-event transients (SETs) in linear integrated circuits have caused anomalies in a number of spacecraft. The consequences of these anomalies have spurred efforts to better understand SETs, including the mechanisms responsible for their generation, the best approaches for testing, how data should be analyzed and presented, and approaches for mitigation

Stephen Buchner; Dale McMorrow

2006-01-01

8

Radiation-induced transient absorption in single mode optical fibers  

SciTech Connect

This paper reviews the measurements conducted by the Los Alamos National Laboratory in support of these NATO efforts wherein radiation-induced transient absorption was measured over time ranges from a few ns to several ..mu..s for two single mode fibers. Experimental conditions were varied to provide data for future development of standarized test conditions for single mode fibers. 8 refs., 11 figs.

Looney, L.D.; Lyons, P.B.

1988-01-01

9

Waveform Observation of Digital Single-Event Transients Employing Monitoring >Transistor Technique  

Microsoft Academic Search

Waveforms of digital single-event transients, radiation-induced voltage transients in logic gates, can be observed by connecting two transistors to a target logic gate. Additional transistors monitor voltage transients through their drain currents, which can be measured using the conventional 50-Omega transmission-line technique widely used for measuring transient currents in single elementary transistors. Experimental results obtained in pulsed-laser irradiation tests demonstrate

Daisuke Kobayashi; Kazuyuki Hirose; Yoshimitsu Yanagawa; Hirokazu Ikeda; Hirobumi Saito; Véronique Ferlet-Cavrois; Dale McMorrow; Marc Gaillardin; Philippe Paillet; Yasuo Arai; Morifumi Ohno

2008-01-01

10

Single Event Transients in Linear Integrated Circuits  

NASA Technical Reports Server (NTRS)

On November 5, 2001, a processor reset occurred on board the Microwave Anisotropy Probe (MAP), a NASA mission to measure the anisotropy of the microwave radiation left over from the Big Bang. The reset caused the spacecraft to enter a safehold mode from which it took several days to recover. Were that to happen regularly, the entire mission would be compromised, so it was important to find the cause of the reset and, if possible, to mitigate it. NASA assembled a team of engineers that included experts in radiation effects to tackle the problem. The first clue was the observation that the processor reset occurred during a solar event characterized by large increases in the proton and heavy ion fluxes emitted by the sun. To the radiation effects engineers on the team, this strongly suggested that particle radiation might be the culprit, particularly when it was discovered that the reset circuit contained three voltage comparators (LM139). Previous testing revealed that large voltage transients, or glitches appeared at the output of the LM139 when it was exposed to a beam of heavy ions [NI96]. The function of the reset circuit was to monitor the supply voltage and to issue a reset command to the processor should the voltage fall below a reference of 2.5 V [PO02]. Eventually, the team of engineers concluded that ionizing particle radiation from the solar event produced a negative voltage transient on the output of one of the LM139s sufficiently large to reset the processor on MAP. Fortunately, as of the end of 2004, only two such resets have occurred. The reset on MAP was not the first malfunction on a spacecraft attributed to a transient. That occurred shortly after the launch of NASA s TOPEX/Poseidon satellite in 1992. It was suspected, and later confirmed, that an anomaly in the Earth Sensor was caused by a transient in an operational amplifier (OP-15) [KO93]. Over the next few years, problems on TDRS, CASSINI, [PR02] SOHO [HA99,HA01] and TERRA were also attributed to transients. In some cases, such events produced resets by falsely triggering circuits designed to protect against over- voltage or over-current. On at least three occasions, transients caused satellites to switch into "safe mode" in which most of the systems on board the satellites were powered down for an extended period. By the time the satellites were reconfigured and returned to full operational state, much scientific data had been lost. Fortunately, no permanent damage occurred in any of the systems and they were all successfully re-activated.

Buchner, Stephen; McMorrow, Dale

2005-01-01

11

Transient tests on an MHD thruster.  

National Technical Information Service (NTIS)

Three different types of transient tests were made -- coast downs to zero voltage and current under open circuit and short circuit conditions, reverses where the applied voltage was reversed to the same or a different value, and jumps where the voltage ap...

E. S. Pierson J. Libera M. Petrick

1993-01-01

12

Tension Transients in Single Isolated Smooth Muscle Cells  

NASA Astrophysics Data System (ADS)

Tension transients were recorded in a single smooth muscle cell. The transient contains a linear elastic response and a biphasic recovery that appear to originate from the cross-bridges. A comparison of transients in smooth and fast skeletal muscle fibers suggests that the cross-bridge in smooth muscle is more compliant than the cross-bridge in striated muscle and that transitions between several cross-bridge states occur more slowly in smooth muscle than in striated muscle.

Warshaw, David M.; Fay, Fredric S.

1983-03-01

13

Transient tests on an MHD thruster  

SciTech Connect

Three different types of transient tests were made -- coast downs to zero voltage and current under open circuit and short circuit conditions, reverses where the applied voltage was reversed to the same or a different value, and jumps where the voltage applied to the thruster was increased without a change in polarity. Most except the coast downs were dons both quickly (voltage changes as fast as possible) and slowly (6 s to complete the voltage change). A few slower (12 s) transients were done. Transient runs were made for water conductivities of 16.2 and 5.09 S/m. In all cases steady-state conditions were established and several seconds of data taken before initiating the transients. Data were measured every 0.75 to 1 .5 second over the time interval of interest. Particular attention was paid to looking for evidence of gas bubbles, and to the chance of the voltage profiles between the electrodes. The data are interpreted based on the behavior of the power supply and the thruster.

Pierson, E.S. (Purdue Univ., Hammond, IN (United States). Dept. of Engineering); Libera, J.; Petrick, M. (Argonne National Lab., IL (United States). Energy Systems Div.)

1993-01-01

14

Future Transient Testing of Advanced Fuels  

SciTech Connect

The transient in-reactor fuels testing workshop was held on May 4–5, 2009 at Idaho National Laboratory. The purpose of this meeting was to provide a forum where technical experts in transient testing of nuclear fuels could meet directly with technical instrumentation experts and nuclear fuel modeling and simulation experts to discuss needed advancements in transient testing to support a basic understanding of nuclear fuel behavior under off-normal conditions. The workshop was attended by representatives from Commissariat à l'Énergie Atomique CEA, Japanese Atomic Energy Agency (JAEA), Department of Energy (DOE), AREVA, General Electric – Global Nuclear Fuels (GE-GNF), Westinghouse, Electric Power Research Institute (EPRI), universities, and several DOE national laboratories. Transient testing of fuels and materials generates information required for advanced fuels in future nuclear power plants. Future nuclear power plants will rely heavily on advanced computer modeling and simulation that describes fuel behavior under off-normal conditions. TREAT is an ideal facility for this testing because of its flexibility, proven operation and material condition. The opportunity exists to develop advanced instrumentation and data collection that can support modeling and simulation needs much better than was possible in the past. In order to take advantage of these opportunities, test programs must be carefully designed to yield basic information to support modeling before conducting integral performance tests. An early start of TREAT and operation at low power would provide significant dividends in training, development of instrumentation, and checkout of reactor systems. Early start of TREAT (2015) is needed to support the requirements of potential users of TREAT and include the testing of full length fuel irradiated in the FFTF reactor. The capabilities provided by TREAT are needed for the development of nuclear power and the following benefits will be realized by the refurbishment and restart of TREAT. •TREAT is an absolute necessity in the suite of reactor fuel test capabilities •TREAT yields valuable information on reactivity effects, margins to failure, fuel dispersal, and failure propagation •Most importantly, interpretation of TREAT experiment results is a stringent test of the integrated understanding of fuel performance.

Jon Carmack

2009-09-01

15

Transient well testing in two-phase geothermal reservoirs  

SciTech Connect

A study of well test analysis techniques in two-phase geothermal reservoirs has been conducted using a three-dimensional, two-phase, wellbore and reservoir simulation model. Well tests from Cerro Prieto and the Hawaiian Geothermal project have been history matched. Using these well tests as a base, the influence of reservoir permeability, porosity, thickness, and heat capacity, along with flow rate and fracturing were studied. Single and two-phase transient well test equations were used to analyze these tests with poor results due to rapidly changing fluid properties and inability to calculate the flowing steam saturation in the reservoir. The injection of cold water into the reservoir does give good data from which formation properties can be calculated.

Aydelotte, S.R.

1980-03-01

16

Transient Oxidation of Single Crystal NiAl+Zr.  

National Technical Information Service (NTIS)

The 800 C oxidation of oriented single crystals of Zr doped beta-NiAl was studied using transmission electron microscopy. The oxide phases and metal-oxide orientation relationships were determined to characterize the transient stages of oxidation prior to...

J. K. Doychak

1983-01-01

17

Transient coherent nonlinear spectroscopy of single quantum dots.  

PubMed

We review our recent advances in four-wave mixing spectroscopy of single semiconductor quantum dots using heterodyne spectral interferometry, a novel implementation of transient nonlinear spectroscopy allowing the study of the transient nonlinear polarization emitted from individual electronic transitions in both amplitude and phase. We present experiments on individual excitonic transitions localized in monolayer islands of GaAs/AlAs quantum wells and in self-assembled CdTe/ZnTe quantum dots. We investigate the formation of the photon echo from individual transitions, both with increasing number of transitions in the ensemble, and in the presence of temporal jitter of the energy of a single transition. The detection of amplitude and phase of the signal allows the implementation of a two-dimensional femtosecond spectroscopy, in which mutual coherent coupling of single quantum dot states can observed and quantified. PMID:21483055

Langbein, Wolfgang; Patton, Brian

2007-07-25

18

40 CFR 86.1333-2010 - Transient test cycle generation.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Transient test cycle generation. 86.1333-2010 Section... Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous...Procedures § 86.1333-2010 Transient test cycle generation. (a) Generating...

2013-07-01

19

Induced shock pulse testing by transient waveform control  

NASA Technical Reports Server (NTRS)

A method of synthesizing an arbitrarily shaped transient time pulse on vibration exciters is described. The transient waveform control technique is based on recent developments in digital time series analysis, the real-time FFT processor. A brief description of the theory, error estimates and hardware/software implementation to the JPL Dynamic Environmental Testing Laboratory is presented.

Kim, B. K.

1973-01-01

20

Interwell pressure transient testing in Midale: A naturally fractured reservoir  

SciTech Connect

The Midale Unit is a naturally fractured carbonate reservoir located in the Williston Basin of southeastern Saskatchewan. Recently, the Midale Working Interest Owners initiated a closely-spaced CO/sub 2/ Flood Pilot project. A comprehensive interwell pressure transient test program was conducted for reservoir characterization purposes. The combination of conventional, pulse, and interference tests resulted in a detailed description of the pilot portion of this naturally fractured reservoir. Selected program data and analyses, including an interpretation technique for multi-well pressure transient tests in wells with negative skins, are presented. A discussion of the pressure transient behaviour observed in wells on typical field spacing is also included.

Beliveau, D.A.

1986-01-01

21

Proton-induced transients in optocouplers: in-flight anomalies, ground irradiation test, mitigation and implications  

Microsoft Academic Search

We present data on recent optocoupler in-flight anomalies and the subsequent ground test irradiation performed. Discussions of the single event mechanisms involved, transient filtering analysis, and design implications are included. Proton-induced transients were observed on higher speed optocouplers with a unique dependence on the incidence particle angle. The results indicate that both direct ionization and nuclear reaction-related mechanisms are responsible

Kenneth A. LaBel; Paul W. Marshall; Cheryl J. Marshall; Mary D'Ordine; Martin Carts; Gary Lum; Hak S. Kim; Christina M. Seidleck; Timothy Powell; Randy Abbott; Janet Barth; E. G. Stassinopoulos

1997-01-01

22

Shaker shock testing using nonstationary random transients  

Microsoft Academic Search

Shock testing plays a critical role in the development of a wide range of structures. Conducting controlled laboratory shock tests on these structures provides essential data on their ability to survive their operational shock environments. Laboratory test specifications establish equivalence relationships between the actual shock environments and the laboratory shock test inputs. In recent years the electrodynamic shaker has proven

T. L. Paez; T. J. Baca

1988-01-01

23

Single event induced transients in I/O devices - A characterization  

NASA Technical Reports Server (NTRS)

The results of single-event upset (SEU) testing performed to evaluate the parametric transients, i.e., amplitude and duration, in several I/O devices, and the impact of these transients are discussed. The failure rate of these devices is dependent on the susceptibility of interconnected devices to the resulting transient change in the output of the I/O device. This failure rate, which is a function of the susceptibility of the interconnected device as well as the SEU response of the I/O device itself, may be significantly different from an upset rate calculated without taking these factors into account. The impact at the system level is discussed by way of an example.

Newberry, D. M.; Kaye, D. H.; Soli, G. A.

1990-01-01

24

Transient behavior of a single-blade horizontal-axis wind turbine  

Microsoft Academic Search

The transient behavior of the wind energy converter (WEC) MONOPTEROS was investigated. This converter is a 1:3 model scale test version (tower height 50 m) of a single-blade 5.4 MW horizontal-axis supercritically operating wind turbine. Aerodynamic and dynamic modelling techniques, the development of control strategies for the transition into\\/out of nominal performance, and simulated and measured time histories with emphasis

R. Wennekers

1984-01-01

25

Thermal-Transient Testing Of Turbine Blades  

NASA Technical Reports Server (NTRS)

Testing apparatus applies pulses of heat to turbine blade to determine resistance to thermal fatigue. Uses nonintrusive inductive heating and records distribution of temperature on blade with infrared video camera. Allows precise control of heating and cooling. Designed for testing blades used in advanced high-pressure, high-temperature turbines.

Wagner, William R.; Pidcoke, Louis H.

1990-01-01

26

SINGLE HEATER TEST FINAL REPORT  

SciTech Connect

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied not just to the hardware, but also to the teamwork and cooperation between multiple organizations performing their part in the test.

J.B. Cho

1999-05-01

27

Pressure-transient test design in tight gas formations  

SciTech Connect

This paper outlines a procedure for pre- and postfracture pressure-transient test design in low-permeability (tight) gas formations. The procedures proposed are based on many years' experience in evaluating low-permeability formations, and particularly on recent experience with Gas Research Inst. (GRI) programs in eastern Devonian gas shales and in western tight-gas formations.

Lee, W.J.

1987-10-01

28

LWR debris from severe in-pile transient tests  

Microsoft Academic Search

Rubble which may form as a result of a severe accident in a light water reactor (LWR) is likely to contain particles of very irregular shapes and sizes and of complex and non-uniform compositions. A number of in-pile tests have been run in the Power Burst Facility (PBF) to characterize LWR fuel behavior under a variety of severe reactor transients.

R. R. Hobbins; B. A. Cook; R. E. Mason

1982-01-01

29

A Technique for Transient Thermal Testing of Thick Structures  

NASA Technical Reports Server (NTRS)

A new open-loop heat flux control technique has been developed to conduct transient thermal testing of thick, thermally-conductive aerospace structures. This technique uses calibration of the radiant heater system power level as a function of heat flux, predicted aerodynamic heat flux, and the properties of an instrumented test article. An iterative process was used to generate open-loop heater power profiles prior to each transient thermal test. Differences between the measured and predicted surface temperatures were used to refine the heater power level command profiles through the iteration process. This iteration process has reduced the effects of environmental and test system design factors, which are normally compensated for by closed-loop temperature control, to acceptable levels. The final revised heater power profiles resulted in measured temperature time histories which deviated less than 25 F from the predicted surface temperatures.

Horn, Thomas J.; Richards, W. Lance; Gong, Leslie

1997-01-01

30

Analysis of steam generator tube rupture transients with single failure  

Microsoft Academic Search

The Gesellschaft fuer Reaktorsicherheit is engaged in the collection and evaluation of light water reactor operating experience as well as analyses for the risk study of the pressurized water reactor (PWR). Within these activities, thermohydraulic calculations have been performed to show the influence of different boundary conditions and disturbances on the steam generator tube rupture (SGTR) transients. The analyses of

Trambauer

1986-01-01

31

A single-view imaging strategy for transient scattered fields  

Microsoft Academic Search

This paper deals with an approach to provide non-invasive characterization of inhomogeneous targets from knowledge of a transient scattered field. This last one is measured by using only one source, which radiates a Gaussian incident pulse. The problem is addressed in the frequency domain rather than directly in the time domain and the reconstruction capabilities of the proposed strategy are

Ilaria Catapano; Kamal Belkebir; Jean-Michel Geffrin

2008-01-01

32

PFR fuel cladding transient test results and analysis  

NASA Astrophysics Data System (ADS)

Fuel Cladding Transient Tests (FCTT) were performed on M316 cladding specimens obtained from mixed-oxide fuel pins irradiated in the Prototype Fast Reactor (PFR) to burnups of 4 and 9 atom percent. In these tests, specimens of fuel cladding were pressurized and heated until failure occurred. Samples of cladding from PFR fuel pins exhibited generally greater strength and ductility than specimens from Experimental Breeder Reactor-II (EBR-II) mixed-oxide fuel pins tested under similar conditions. Apparently, the PFR cladding properties were not degraded by a fuel adjacency effect (FAE) observed in fuel pin cladding from EBR-II irradiations. A recently developed model of grain boundary cavity growth was used to predict the results of the tests conducted on PFR cladding. It was found that the predicted failure temperatures for the relevant internal pressures were in good agreement with experimental failure temperatures.

Cannon, N. S.; Hunter, C. W.; Kear, K. L.; Wood, M. H.

1986-05-01

33

Transient analysis of lossless single-phase nonuniform transmission lines  

SciTech Connect

A new method has been developed to study the transient behavior of nonuniform transmission lines whose parameters can have any arbitrary space variation. Using the exponential line as a building block, s-domain expressions are obtained for the voltage and current at any point along the nonuniform line. An efficient numerical Laplace-transform inversion technique is then used to compute the time-domain solution. Computer simulations and comparisons with other solution methods are included.

Oufi, E.A.; AlFuhaid, A.S.; Saied, M.M. (Kuwait Univ., Safat (Kuwait). Electrical and Computer Engineering Dept.)

1994-07-01

34

Single-Voxel Recording of Voltage Transients in Dendritic Spines  

Microsoft Academic Search

We report sensitive recording of membrane potential in single dendritic spines in cortical neurons within a brain slice using two-photon excitation and a new, fluorinated, intracellularly loaded organic dye, di-2-AN(F)EPPTEA. With a two-photon excitation wavelength of 1060 nm, we achieve voltage sensitivity of >16% change in fluorescence per 100 mV. By targeting single spines in single-voxel recordings, we attain excellent single\\/noise quality, with back-propagating

Ping Yan

2011-01-01

35

Large transient fault current test of an electrical roll ring  

NASA Technical Reports Server (NTRS)

The space station uses precision rotary gimbals to provide for sun tracking of its photoelectric arrays. Electrical power, command signals and data are transferred across the gimbals by roll rings. Roll rings have been shown to be capable of highly efficient electrical transmission and long life, through tests conducted at the NASA Lewis Research Center and Honeywell's Satellite and Space Systems Division in Phoenix, AZ. Large potential fault currents inherent to the power system's DC distribution architecture, have brought about the need to evaluate the effects of large transient fault currents on roll rings. A test recently conducted at Lewis subjected a roll ring to a simulated worst case space station electrical fault. The system model used to obtain the fault profile is described, along with details of the reduced order circuit that was used to simulate the fault. Test results comparing roll ring performance before and after the fault are also presented.

Yenni, Edward J.; Birchenough, Arthur G.

1992-01-01

36

Behavior of metallic fuel in treat transient overpower tests  

SciTech Connect

Results and analyses are reported for TREAT in-pile transient overpower tests of margin to cladding failure and pre-failure axial expansion of metallic fuel. In all cases the power rise was exponential on an 8 s period until either incipient or actual cladding failure was achieved. Test fuel included EBR-II driver fuel and ternary alloy, the reference fuel of the Intergral Fast Reactor concept. Test pin burnup spanned the widest range available. The nature of the observed cladding failure and resultant fuel dispersals is described. Simple models are presented which describe observed cladding failures and pre-failure axial expansions yet are general enough to apply to all metal fuel types.

Bauer, T.H.; Wright, A.E.; Robinson, W.R.; Klickman, A.E.

1988-01-01

37

Relationship between presynaptic calcium transients and postsynaptic currents at single ?-aminobutyric acid (GABA)ergic boutons  

PubMed Central

Postsynaptic responses to stereotyped activation of single axons are known to fluctuate, but the origin of synaptic variability in the vertebrate central nervous system is still unclear. To test the hypothesis that fluctuations of inhibitory postsynaptic currents reflect variations in presynaptic Ca2+ concentration, we examined single GABAergic axodendritic contacts in low-density cultures. Collicular neurons from rat embryos were loaded with the Ca2+ indicator Oregon Green 488 BAPTA-1. Presynaptic axon terminals were visualized by staining with the styryl dye RH414. Under the condition of action potential block, RH414-labeled boutons were activated selectively by current pulses applied through a fine-tipped glass pipette. Short (1- to 3-ms) depolarization of isolated boutons resulted in stimulus-locked changes of presynaptic Ca2+ concentration ([Ca2+]pre) and in evoked inhibitory postsynaptic currents (eIPSCs). Varying the strength of the stimulating currents produced a wide amplitude range of both presynaptic fluorescence transients (up to 220% of the resting value) and postsynaptic conductance changes (up to 2–3 nS). It was found that average eIPSCs displayed an approximately third-power dependency on [Ca2+]pre. Transmitter release retained its probabilistic character throughout the range of observed [Ca2+]pre values. In any tested single bouton, maximal eIPSCs occurred in association with the largest [Ca2+]pre transients, but failures were present at any [Ca2+]pre. The increase of maximal eIPSC amplitudes in connection with higher [Ca2+]pre supports the hypothesis that GABAergic boutons have the capacity to regulate synaptic strength by changing the number of simultaneously released vesicles.

Kirischuk, S.; Veselovsky, N.; Grantyn, R.

1999-01-01

38

Modeling transient streaming potentials in falling-head permeameter tests.  

PubMed

We present transient streaming potential data collected during falling-head permeameter tests performed on samples of two sands with different physical and chemical properties. The objective of the work is to estimate hydraulic conductivity (K) and the electrokinetic coupling coefficient (Cl ) of the sand samples. A semi-empirical model based on the falling-head permeameter flow model and electrokinetic coupling is used to analyze the streaming potential data and to estimate K and Cl . The values of K estimated from head data are used to validate the streaming potential method. Estimates of K from streaming potential data closely match those obtained from the associated head data, with less than 10% deviation. The electrokinetic coupling coefficient was estimated from streaming potential vs. (1) time and (2) head data for both sands. The results indicate that, within limits of experimental error, the values of Cl estimated by the two methods are essentially the same. The results of this work demonstrate that a temporal record of the streaming potential response in falling-head permeameter tests can be used to estimate both K and Cl . They further indicate the potential for using transient streaming potential data as a proxy for hydraulic head in hydrogeology applications. PMID:23782328

Malama, Bwalya; Revil, André

2014-07-01

39

40 CFR 1039.510 - Which duty cycles do I use for transient testing?  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Which duty cycles do I use for transient testing? 1039...Procedures § 1039.510 Which duty cycles do I use for transient testing? ...with one of the following transient duty cycles to determine whether it meets the...

2013-07-01

40

Single-voxel recording of voltage transients in dendritic spines.  

PubMed

We report sensitive recording of membrane potential in single dendritic spines in cortical neurons within a brain slice using two-photon excitation and a new, fluorinated, intracellularly loaded organic dye, di-2-AN(F)EPPTEA. With a two-photon excitation wavelength of 1060 nm, we achieve voltage sensitivity of >16% change in fluorescence per 100 mV. By targeting single spines in single-voxel recordings, we attain excellent single/noise quality, with back-propagating action potentials (bAPs) visible in single sweeps while recording at 10 kHz. This recording rate allows us to reliably assess fast bAP dynamics on single sweeps including bAP rise times of 0.5 ms. The amplitude and propagation delays of the bAPs are similar among different spines located within the same dendritic region, and this is true despite large differences in spine size. The interregion differences in bAP waveforms in spines vary in relation to their distance from the soma and the caliber of their parent dendrites. PMID:21767473

Acker, Corey D; Yan, Ping; Loew, Leslie M

2011-07-20

41

Single Event Transients in Voltage Regulators for FPGA Power Supply Applications  

NASA Technical Reports Server (NTRS)

As with other bipolar analog devices, voltage regulators are known to be sensitive to single event transients (SET). In typical applications, large output capacitors are used to provide noise immunity. Therefore, since SET amplitude and duration are generally small, they are often of secondary importance due to this capacitance filtering. In low voltage applications, however, even small SET are a concern. Over-voltages may cause destructive conditions. Under-voltages may cause functional interrupts and may also trigger electrical latchup conditions. In addition, internal protection circuits which are affected by load as well as internal thermal effects can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. In the case of FPGA power supplies applications, SETS are critical. For example, in the case of Actel FPGA RTAX family, core power supply voltage is 1.5V. Manufacturer specifies an absolute maximum rating of 1.6V and recommended operating conditions between 1.425V and 1.575V. Therefore, according to the manufacturer, any transient of amplitude greater than 75 mV can disrupt normal circuit functions, and overvoltages greater than 100 mV may damage the FPGA. We tested five low dropout voltage regulators for SET sensitivity under a large range of circuit application conditions.

Poivey, Christian; Sanders, Anthony; Kim, Hak; Phan, Anthony; Forney, Jim; LaBel, Kenneth A.; Karsh, Jeremy; Pursley, Scott; Kleyner, Igor; Katz, Richard

2006-01-01

42

Generation of single-cycle THz transients with high electric-field amplitudes  

Microsoft Academic Search

Single-cycle terahertz (THz) transients in the frequency range 0.3-7 THz with electric-field amplitudes of more than 400 kV\\/cm are generated by four-wave mixing of the fundamental and the second harmonic of 25 fs pulses from a Ti:sapphire amplifier in ionized air. These transients are fully characterized by electro-optic sampling with ZnTe and GaP crystals. One can tune the center frequency

T. Bartel; P. Gaal; K. Reimann; Michael Woerner; Thomas Elsaesser

2005-01-01

43

Review of single transient oscillographic recorders with gigahertz bandwidth  

SciTech Connect

In laser driven inertial confinement fusion research, at Livermore, we are diagnosing many phenomena that occur in a time frame that exceeds the capabilities of even the most advanced, present day oscillographic recording instruments. Many of the by-products of the interaction between the laser beam and fuel pellet are monitored to determine the specifics of the fusion process. By the use of appropriate detectors, we convert the information contained in the radiated by-products to electrical signals which are recorded on high bandwidth oscillographic recorders. Our present range of recording capabilities for one x-ray diagnostic measurement in use at Livermore is shown. A commonly used configuration consists of an XRD-31 x-ray detector connected to a direct access Tektronix R7912 transient digitizer using 1/2 in. diameter air dielectric coaxial cable. This configuration gives a system fwhm of approximately 335 ps. Our premier configuration, on the other hand, consists of an improved response detector and a French Thomson-CSF TSN-660 oscilloscope with a shorter length of coaxial cable (typically 20 feet). The system fwhm in this case is less than 120 ps which is our fastest oscillographic recording system at the present time.

Campbell, D.E.

1982-10-20

44

Modulation induced transient chirping in single frequency lasers  

Microsoft Academic Search

Wavelength excursions with magnitudes as large as 6 A are seen to occur in single frequency lasers (both C³ and DFB) during a transition from one power level to another. The wavelength shifts briefly toward shorter wavelengths and then back to the equilibrium value during turn-on and toward longer wavelengths and back during turn-off. These excursions, which are well explained

R. Linke

1985-01-01

45

Transient absorption spectroscopy and imaging of individual chirality-assigned single-walled carbon nanotubes.  

PubMed

Femtosecond transient absorption microscopy was employed to study the excited-state dynamics of individual semiconducting single-walled carbon nanotubes (SWNTs) with simultaneously high spatial (?200 nm) and temporal (?300 fs) resolution. Isolated SWNTs were located using atomic force microscopy, and Raman spectroscopy was employed to determine the chiral index of select nanotubes. This unique experimental approach removes sample heterogeneity in ultrafast measurements of these complex materials. Transient absorption spectra of the individual SWNTs were obtained by recording transient absorption images at different probe wavelengths. These measurements provide new information about the origin of the photoinduced absorption features of SWNTs. Transient absorption traces were also collected for individual SWNTs. The dynamics show a fast, ?1 ps, decay for all the semiconducting nanotubes studied, which is significantly faster than the previously reported decay times for SWNT suspensions. We attributed this fast relaxation to coupling between the excitons created by the pump laser pulse and the substrate. PMID:22577898

Gao, Bo; Hartland, Gregory V; Huang, Libai

2012-06-26

46

TRANSPA: a code for transient thermal analysis of a single fuel pin  

SciTech Connect

An analytical model (TRANSPA) for the transient thermal analysis of a single uranium carbide fuel pin was developed. This model uses thermal boundary conditions obtained from COBRA-WC output and calculates the transient thermal response of a single fuel pin to changes in internal power generation, coolant flowrate, or fuel pin physical configuration. The model uses the MITAS finite difference thermal analyzer. MITAS provides the means to input separate conductance models through the use of a user subroutine input capability. The model is a lumped-mass representation of the fuel pin using 26 nodes and 42 conductors. Run time for each transient analysis is approximately one minute of central processor time on the NOS operating system.

Prenger, F.C.

1985-02-01

47

Single Sample t-Test  

NSDL National Science Digital Library

This page will perform a t-test for the significance of the difference between the observed mean of a sample and a hypothetical mean of the population from which the sample is randomly drawn. The user will be asked to specify the sample size as the page opens.

Lowry, Richard, 1940-

2008-09-05

48

Single Sample t-test  

NSDL National Science Digital Library

This tutorial on the "One Sample t-Test" includes its definition, assumptions, hypotheses, and results. An example using output from the WINKS software is given, but those without the software can still use the tutorial. An exercise is given at the end that can be done with any statistical software package.

2009-01-09

49

Revisiting single photon avalanche diode current-voltage modeling and transient characteristics  

NASA Astrophysics Data System (ADS)

A model for the current-voltage and transient behavior of Single Photon Avalanche Diodes (SPADs) based on device physics is presented. The results of the model are compared to actual measurements and a reasonable fit is seen. Additionally, the model provides a useful tool for designing quenching circuitry and determining optimal operation conditions of the SPAD.

Javitt, M.; Savuskan, V.; Merhav, T.; Nemirovsky, Y.

2014-05-01

50

Digital Computer Solution of Electromagnetic Transients in Single-and Multiphase Networks  

Microsoft Academic Search

Electromagnetic transients in arbitrary single- or multiphase networks are solved by a nodal admittance matrix method. The formulation is based on the method of characteristics for distributed parameters and the trapezoidal rule of integration for lumped parameters. Optimally ordered triangular factorization with sparsity techniques is used in the solution. Examples and programming details illustrate the practicality of the method.

Hermann Dommel

1969-01-01

51

The transient and qualitative performance of a self-excited single-phase induction generator  

Microsoft Academic Search

The modeling and transient performance of a single-phase induction generator with series or parallel connected load is the theme of this paper. The system of equations are expressed in terms of flux linkages and includes the effect of magnetizing flux linkage saturation. Generator self-excitation and voltage collapse phenomena are simulated. The balance of the paper deals with the qualitative behavior

Olorunfemi Ojo

1995-01-01

52

Dendritic calcium transients evoked by single back-propagating action potentials in rat neocortical pyramidal neurons.  

PubMed

1. Dendrites of rat neocortical layer V pyramidal neurons were loaded with the Ca2+ indicator dye Calcium Green-1 (CG-1) or fluo-3, and the mechanisms which govern action potential (AP)-evoked transient changes in dendritic cytosolic Ca2+ concentration ([Ca2+]i) were examined. APs were initiated either by synaptic stimulation or by depolarizing the soma or dendrite by current injection, and changes in fluorescence of the indicator dye were measured in the proximal 170 microns of the apical dendrite. 2. Simultaneous two-pipette recordings of APs from the soma and apical dendrite, and dendritic fluorescence imaging indicated that a single AP propagating from the soma into the apical dendrite evokes a rapid transient increase in fluorescence indicating a transient increase in [Ca2+]i. At 35-37 degrees C the decay time constant of the fluorescence transient following an AP was around 80 ms. 3. Voltage-activated Ca2+ channels (VACCs) of several subtypes mediated the AP-evoked fluorescence transient in the proximal (100-170 microns) apical dendrite. The AP-evoked fluorescence transient resulted from Ca2+ entry through L-type (nifedipine sensitive; 25%), N-type (omega-conotoxin GVIA sensitive; 28%) and P-type (omega-agatoxin IVA sensitive; 10%) Ca2+ channels and through Ca2+ channels (R-type) not sensitive to L-, N- and P-type Ca2+ channel blockers (cadmium ion sensitive; 37%). 4. The decay time course of the dendritic fluorescence transient was prolonged by the blockers of endoplasmic reticulum (ER) Ca(2+)-ATPase, cyclopiazonic acid and thapsigargin, suggesting that uptake of Ca2+ into the ER in dendrites governs clearance of dendritic Ca2+. 5. The decay time course of the fluorescence transient was slightly prolonged by benzamil, a blocker of plasma membrane Na(+)-Ca2+ exchange and by calmidazolium, a blocker of the calmodulin-dependent plasma membrane Ca(2+)-ATPase, suggesting that these pathways are less important for dendrite Ca2+ clearance following a single AP. Neither the mitochondrial uncoupler carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) nor the blocker of Ca2+ uptake into mitochondria, Ruthenium Red, had any measurable effect on the decay time course of the fluorescence transient. 6. Dendritic fluorescence transients measured during trains of dendritic APs began to summate at impulse frequencies of 5 APs s-1. At higher frequencies APs caused a concerted and maintained elevation of dendritic fluorescence during the train.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7658365

Markram, H; Helm, P J; Sakmann, B

1995-05-15

53

Structural Analysis of Fuel Assembly Clads for the Upgraded Transient Reactor Test Facility (TREAT Upgrade).  

National Technical Information Service (NTIS)

The Upgraded Transient Reactor Test Facility (TREAT Upgrade) is designed to test full-length, pre-irradiated fuel pins of the type used in large LMFBRs under accident conditions, such as severe transient overpower and loss-of-coolant accidents. In TREAT U...

T. F. Ewing T. S. Wu

1986-01-01

54

40 CFR 1048.510 - What transient duty cycles apply for laboratory testing?  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false What transient duty cycles apply for laboratory testing? 1048...Procedures § 1048.510 What transient duty cycles apply for laboratory testing? ...the engine on a dynamometer with the duty cycle described in Appendix II to...

2013-07-01

55

PHASE I SINGLE CELL ELECTROLYZER TEST RESULTS  

Microsoft Academic Search

This document reports the results of Phase I Single Cell testing of an SO-Depolarized Water Electrolyzer. Testing was performed primarily during the first quarter of FY 2008 at the Savannah River National Laboratory (SRNL) using an electrolyzer cell designed and built at SRNL. Other facility hardware were also designed and built at SRNL. This test further advances this technology for

J Steimke; T Timothy Steeper

2008-01-01

56

Single event transient analysis of an SOI operational amplifier for use in low-temperature Martian exploration  

NASA Astrophysics Data System (ADS)

The next generation of Martian rovers to be launched by Jet Propulsion Laboratory (JPL) are to examine polar regions where temperatures are extremely low and the absence of an earth-like atmosphere results in high levels of cosmic radiation at ground level. Cosmic rays lead to a plethora of radiation effects including Single Event Transients which can severely degrade microelectronic functionality. As such, a radiation-hardened, temperature compensated CMOS Single-on-insulator (SOI) Operational Amplifier has been designed for JPL by the University of Tennessee and fabricated by Honeywell using the SOI V process. SOI technology has been shown to be far less sensitive to transient effects than both bulk and epilayer Si. Broad beam heavy-ion tests at the University of Texas A&M using Kr and Xe beams of energy 25 MeV/amu were performed to ascertain the duration and severity of the SET for the op-amp configured for a low and high gain application. However, some ambiguity regarding the location of transient formation required the use of a focused MeV ion microbeam. A 36 MeV O 6+ microbeam at the Sandia National Laboratory (SNL) was used to image and verify regions of particular concern.

Laird, Jamie Stuart; Scheick, Leif; Vizkelethy, Gyorgy; Mojarradi, Mohammad M.; Miyahira, Tetsuo; Chen, Yuan; Blalock, Benjamin; Greenwell, Robert; Terry, Stephen; Doyle, Barney

2007-07-01

57

Single Event Transient Analysis of an SOI Operational Amplifier for Use in Low-Temperature Martian Exploration  

NASA Technical Reports Server (NTRS)

The next generation of Martian rover#s to be launched by JPL are to examine polar regions where temperatures are extremely low and the absence of an earth-like atmosphere results in high levels of cosmic radiation at ground level. Cosmic rays lead to a plethora of radiation effects including Single Event Transients (SET) which can severely degrade microelectronic functionality. As such, a radiation-hardened, temperature compensated CMOS Single-On-Insulator (SOI) Operational Amplifier has been designed for JPL by the University of Tennessee and fabricated by Honeywell using the SOI V process. SOI technology has been shownto be far less sensitive to transient effects than both bulk and epilayer Si. Broad beam heavy-ion tests at the University of Texas A&M using Kr and Xebeams of energy 25MeV/amu were performed to ascertain the duration and severity of the SET for the op-amp configured for a low and high gain application. However, some ambiguity regarding the location of transient formation required the use of a focused MeV ion microbeam. A 36MeV O6(+) microbeam. the Sandia National Laboratory (SNL) was used to image and verify regions of particular concern. This is a viewgraph presentation

Laird, Jamie S.; Scheik, Leif; Vizkelethy, Gyorgy; Mojarradi, Mohammad M; Chen, Yuan; Miyahira, Tetsuo; Blalock, Benjamin; Greenwell, Robert; Doyle, Barney

2006-01-01

58

ANSYS Benchmark of the Single Heater Test.  

National Technical Information Service (NTIS)

The Single Heater Test (SHT) is the first of three in-situ thermal tests included in the site characterization program for the potential nuclear waste monitored geologic repository at Yucca Mountain. The heating phase of the SHT started in August 1996 and...

2006-01-01

59

A 10 GHz bandwidth, single transient, digitized oscilloscope with 20 GHz capability  

SciTech Connect

EG&G/EM has developed an oscilloscope with a {minus}3 dB bandwidth greater than 10 GHz. Its rolloff characteristics are such that single-transient data greater than 20 GHz may be captured. A demountable CCD camera records the oscilloscope trace and is provided with PC-compatible capture and data processing software. The capabilities of the oscilloscope, camera, and its processing software are described and examples of the system`s performance is shown.

Hudson, C.L.; Kocimski, S.M. [EG and G Energy Measurements, Inc., Santa Barbara, CA (United States). Santa Barbara Operations; Spector, J. [EG and G Energy Measurements, Inc., Pleasanton, CA (United States). Amador Valley Operations; Thomas, J.B. [EG and G Energy Measurements, Inc., Woburn, MA (United States). Cathode Ray Tube Opeations; Woodstra, R.R. [EG and G Energy Measurements, Inc., Albuquerque, NM (United States). Kirtland Operations

1993-12-31

60

The transient and qualitative performance of a self-excited single-phase induction generator  

SciTech Connect

The modeling and transient performance of a single-phase induction generator with series or parallel connected load is the theme of this paper. The system of equations are expressed in terms of flux linkages and includes the effect of magnetizing flux linkage saturation. Generator self-excitation and voltage collapse phenomena are simulated. The balance of the paper deals with the qualitative behavior of the generator using concepts of harmonic balance and system bifurcation.

Ojo, O. [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Electrical Engineering] [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Electrical Engineering

1995-09-01

61

A 10 GHz bandwidth, single transient, digitized oscilloscope with 20 GHz capability  

Microsoft Academic Search

EG G\\/EM has developed an oscilloscope with a [minus]3 dB bandwidth greater than 10 GHz. Its rolloff characteristics are such that single-transient data greater than 20 GHz may be captured. A demountable CCD camera records the oscilloscope trace and is provided with PC-compatible capture and data processing software. The capabilities of the oscilloscope, camera, and its processing software are described

C. L. Hudson; S. M. Kocimski; J. Spector; J. B. Thomas; R. R. Woodstra

2010-01-01

62

A 10 GHz bandwidth, single transient, digitized oscilloscope with 20 GHz capability  

Microsoft Academic Search

EG&G\\/EM has developed an oscilloscope with a ?3 dB bandwidth greater than 10 GHz. Its rolloff characteristics are such that single-transient data greater than 20 GHz may be captured. A demountable CCD camera records the oscilloscope trace and is provided with PC-compatible capture and data processing software. The capabilities of the oscilloscope, camera, and its processing software are described and

C. L. Hudson; S. M. Kocimski; J. Spector; J. B. Thomas; R. R. Woodstra

1994-01-01

63

A 10 GHz bandwidth, single transient, digitized oscilloscope with 20 GHz capability  

Microsoft Academic Search

EG&G\\/EM has developed an oscilloscope with a -3 dB bandwidth greater than 10 GHz. Its rolloff characteristics are such that single-transient data greater than 20 GHz may be captured. A demountable CCD camera records the oscilloscope trace and is provided with PC-compatible capture and data processing software. The capabilities of the oscilloscope, camera, and its processing software are described and

C. L. Hudson; S. M. Kocimski; J. Spector; J. B. Thomas; R. R. Woodstra

1993-01-01

64

40 CFR Appendix I to Part 1037 - Heavy-Duty Transient Chassis Test Cycle  

Code of Federal Regulations, 2013 CFR

...2013-07-01false Heavy-Duty Transient Chassis Test CycleI Appendix I to Part 1037Protection of Environment ENVIRONMENTAL...FROM NEW HEAVY-DUTY MOTOR VEHICLESPt. 1037, App. I Appendix I to Part 1037âHeavy-Duty Transient...

2013-07-01

65

Single Event Effect (SEE) Test Planning 101  

NASA Technical Reports Server (NTRS)

This is a course on SEE Test Plan development. It is an introductory discussion of the items that go into planning an SEE test that should complement the SEE test methodology used. Material will only cover heavy ion SEE testing and not proton, LASER, or other though many of the discussed items may be applicable. While standards and guidelines for how-to perform single event effects (SEE) testing have existed almost since the first cyclotron testing, guidance on the development of SEE test plans has not been as easy to find. In this section of the short course, we attempt to rectify this lack. We consider the approach outlined here as a "living" document: mission specific constraints and new technology related issues always need to be taken into account. We note that we will use the term "test planning" in the context of those items being included in a test plan.

LaBel, Kenneth A.; Pellish, Jonathan; Berg, Melanie D.

2011-01-01

66

Experimental capabilities of the transient reactor test (TREAT) facility.  

SciTech Connect

The TREAT facility was designed and built in the 1950s to provide a transient reactor for conducting safety experiments on reactor fuels. Throughout its almost 40-year history, it has proven to be a safe, reliable, and versatile facility, compiling a distinguished record of successful experiments. Several major improvements to the facility have been made, including an expansion of the building and of equipment handling capability, and enlargement of the access hole above the core, rearrangement of the reactor's control rods to provide more-uniform flux profiles, installation of improved reactor computer-control systems, a feedback system that safely allows real-time changes in power transients depending upon events occurring in the experiment, and several upgrades in the fast neutron hodoscope for improved experiment-fuel-motion diagnostics. The original TREAT fuel is still in use, however, since it appears to have no degradation from its many years of service.

Crawford, D. C.

1998-07-28

67

Technetium-99m HM-PAO single photon emission computed tomography imaging in transient global amnesia.  

PubMed

Five right-handed patients with pure transient global amnesia were evaluated with technetium-99m hexamethylpropyleneamine oxime single photon emission computed tomography after the amnesic attack. Independent of the interval between the procedure and the amnesic episode, single photon emission computed tomography demonstrated a decreased cerebral blood flow in the left temporal lobe in one patient and in the left parietotemporal region in three patients, with a more marked reduction in the temporal lobe. The remaining three patients were normal. A control single photon emission computed tomographic study was carried out in one patient 3 months after the amnesic attack and showed a left-sided persistent temporal hypoperfusion. These findings suggest that in some patients, transient global amnesia can be due to a vascular mechanism requiring strong investigations for vascular risk factors and appropriate treatment. During a follow-up period of 12 to 32 months, none of the patients with regional hypoperfusion suffered cerebrovascular events, suggesting that single photon emission computed tomography has no predictive value for further stroke. PMID:1580818

Laloux, P; Brichant, C; Cauwe, F; Decoster, P

1992-05-01

68

Steady-state and transient A\\/F control requirements for cold operation of a 1. 6 liter engine with single-point fuel injection  

Microsoft Academic Search

An engine dynamometer test facility capable of controlling temperatures from 0°F to 150°F was used to investigate A\\/F control characteristics of a 1.6 liter engine with single point fuel injection. Two types of tests were run. In the first, the effect of induction system temperature on manifold wall wetting and transient A\\/F control was determined. In the second, a cold

C. F. Aquino; S. R. Fozo

1985-01-01

69

SINGLE LABORATORY EVALUATION OF PHYTOTOXICITY TEST  

EPA Science Inventory

The phytotoxicity method is a screening test used to predict the potential impact of chemicals on seed germination and early seedling growth. An evaluation of the procedure was conducted in order to establish the data quality that could be achieved within a single laboratory and ...

70

Pressure-transient analysis of fracture-calibration tests  

SciTech Connect

Fracture-calibration pressure decline has been used for determination of the leakoff coefficient, a bulk variable describing the process of fluid influx into the reservoir, normal to the created fracture face. In this work, the fluid loss is modeled in terms of the controlling mechanisms: flow through the filter cake, the invaded zone, and the reservoir. A rigorous model describes unsteady-state fluid flow from fractures of varying area into the formation, with the filter cake considered as a time- and rate-dependent skin effect. The injection history is superposed on the pressure decline. This work provides a straight-line technique for determination of reservoir permeability and fracture-face resistance. Log-log diagnostic plots provide the means to recognize visually whether the transient response is dominated by flow in the reservoir or at the fracture face. The authors found that the pressure transient very frequently is dominated by the flow in the reservoir rather than through the filter cake. The reservoir permeability (an essential value for fracture design that is usually not available) can be estimated, while the model captures all trends of the falloff-pressure variation.

Mayerhofer, M.J. [Mining Univ. Leoben (Austria); Ehlig-Economides, C. [Schlumberger Well Services, Houston, TX (United States). Interpretation Dept.; Economides, M.J. [Texas A and M Univ., College Station, TX (United States)

1995-03-01

71

New insight into the parasitic bipolar amplification effect in single event transient production  

NASA Astrophysics Data System (ADS)

In this paper, a new method is proposed to study the mechanism of charge collection in single event transient (SET) production in 90 nm bulk complementary metal oxide semiconductor (CMOS) technology. We find that different from the case in the pMOSFET, the parasitic bipolar amplification effect (bipolar effect) in the balanced inverter does not exist in the nMOSFET after the ion striking. The influence of the substrate process on the bipolar effect is also studied in the pMOSFET. We find that the bipolar effect can be effectively mitigated by a buried deep P+-well layer and can be removed by a buried SO2 layer.

Chen, Jian-Jun; Chen, Shu-Ming; Liang, Bin; Deng, Ke-Feng

2012-01-01

72

Final Report for TREAT Transient Overpower Tests R9 and R12 -- Part 2  

SciTech Connect

Tests R9 and R12 were the first in-pile simulations of a 50c/s transient overpower (TOP) hypothetical core-disruptive accident (HCDA) as expected in the Fast Test Reactor (FTR). The tests employed prototypic thermal-hydraulic inlet and initial conditions, and used full-length FTR, fresh fuel pins. The initial conditions and power histories of tl1e two tests were prescribed alike to a point after the initial dbruptive pin failures. Test R9, the first of the two, provided data on the unterminated transient and was used to tailor the termination of test R12. Test R9 was allowed to continue on the overpower transient to the full energy capability of the Transient Test Reactor (TREAT) facility. This ensured failure of the test-bundle, but resulted in overpowering the test well beyond the predicted FTR response to the 50c/s HCDA TOP. Test R12, with the benefit of R9 transient data, was designed to scram TREAT just after the initial disruptive pin failures. Thereby, the response of test R12 was as close as possible to the actual FTR response to this HCDA as could be simulated in TREAT. Both R9 and R12 had objectives to examine the transient fuel motion due to the 50c/s TOP. Additional objectives were for R9 to examine fuel sweepout and for R12 to determine post-fuel relocation test section coolability. The results of the experiments demonstrated sweepout downstream of the active fuel zone: R9 - 50% and R12 - 5% of the total fuel inventory. Due to the excess input energy in test R9, the coolant channel was totally blocked in the region of the upper reflectors. Termination of the transient after the initial disruptive fuel pin failures in R12 resulted in less fuel motion, but allowed the coolant flow to return to 100% of full flow and quickly cool the test section. The termination of the R12 transient was accomplished by a flow meter signal feedback to the TREAT control computer. The test results indicate that: 1. The sweepout of fuel was dispersive and a coolable geometry remained. 2. The margin between fuel failure and normal operation power levels is high (several times nominal power); and, 3. Explosive, energetic vaporization events were not observed.

Koopman, R. N.; Murphy, W. F.; Fink, C. L.; Kramer, N. A.; Stewart, R. R.

1980-04-01

73

NEXT Single String Integration Test Results  

NASA Technical Reports Server (NTRS)

As a critical part of NASA's Evolutionary Xenon Thruster (NEXT) test validation process, a single string integration test was performed on the NEXT ion propulsion system. The objectives of this test were to verify that an integrated system of major NEXT ion propulsion system elements meets project requirements, to demonstrate that the integrated system is functional across the entire power processor and xenon propellant management system input ranges, and to demonstrate to potential users that the NEXT propulsion system is ready for transition to flight. Propulsion system elements included in this system integration test were an engineering model ion thruster, an engineering model propellant management system, an engineering model power processor unit, and a digital control interface unit simulator that acted as a test console. Project requirements that were verified during this system integration test included individual element requirements ; integrated system requirements, and fault handling. This paper will present the results of these tests, which include: integrated ion propulsion system demonstrations of performance, functionality and fault handling; a thruster re-performance acceptance test to establish baseline performance: a risk-reduction PMS-thruster integration test: and propellant management system calibration checks.

Soulas, George C.; Patterson, Michael J.; Pinero, Luis; Herman, Daniel A.; Snyder, Steven John

2010-01-01

74

Generation of THz transients by photoexcited single-crystal GaAs meso-structures  

NASA Astrophysics Data System (ADS)

We report a sub-picosecond photoresponse and THz transient generation of GaAs single-crystal mesoscopic platelets excited by femtosecond optical pulses. Our structures were fabricated by a top-down technique, by patterning an epitaxial, 500-nm-thick GaAs film grown on top of an AlAs sacrificial layer and then transferring the resulting etched away 10 × 20-?m2 platelets onto an MgO substrate using a micropipette. The freestanding GaAs devices, incorporated into an Au coplanar strip line, exhibited extremely low dark currents and ~0.4 % detection efficiency at 10 V bias. The all-optical, pump-probe carrier dynamics analysis showed that, for 800-nm-wavelength excitation, the intrinsic relaxation of photocarriers featured a 310-fs-wide transient with a 290 fs fall time. We have also carried out a femtosecond, time-resolved electro-optic characterization of our devices and recorded along the transmission line the electrical transients as short as ~600 fs, when the platelet was excited by a train of 100-fs-wide, 800-nm-wavelength optical laser pulses. The platelets have been also demonstrated to be very efficient generators of free-space propagating THz transients with the spectral bandwidth exceeding 2 THz. The presented performance of the epitaxial, freestanding GaAs meso-structured photodevices makes them uniquely suitable for THz-frequency optoelectronic applications, ranging from ultrafast photodetectors to THz-bandwidth optical-to-electrical transducers and photomixers.

Zhang, Jie; Mikulics, Martin; Adam, Roman; Grützmacher, Detlev; Sobolewski, Roman

2013-12-01

75

Transient x-ray diffraction to measure the dynamic response of shocked lithium fluoride single crystal  

NASA Astrophysics Data System (ADS)

Transient x-ray diffraction, also called time-resolved x-ray diffraction and dynamic x-ray diffraction, is one novel diagnostic technique for probing shocked solids. It can provide direct information about microscopic mechanisms governing shock-induced deformation and structural changes at atomistic scales with nanosecond and picoseconds resolution, and lately, it has become possible to measure the structure of transients with sub-picoseconds and sub-Angstrom resolution with the development of ultrafast lasers which can produce femtosecond electron and x-ray pulses in the form of characteristics emission lines as well as x-ray continua in the keV range. In this paper, we detect and measure directly the dynamic response of lithium fluoride single crystal shocked compressed by laser irradiation in SHENGUANG II. In our experiments, high-intensity lasers irradiated a thin Cu foil to generate helium-like rays as x-ray source. Film (IP--image plate) recorded x rays diffracted from multiple lattice planes both perpendicular and oblique angles to the shock loading direction [100]. We gained the diffraction signals of the lattice planes (200) shocked and unshocked, what's more, other lattices (113), (1-13). The positions of the diffraction lines associated with the (200) lattice plane indicated compression of the lattice along [100] direction by 13%. In the experiment, a large-angle detector consists of two films-one rectangular in shape,one triangular in shape that are positioned to record x rays diffracted from a shocked single crystal nearly within a full ? steradian. The experiment shows that transient x-ray diffraction can diagnose the dynamical response of solid with higher resolution.

Wang, Hai-rong; Ye, Yan; Yang, Qing-guo; Li, Mu; Xiao, Sha-li; Li, Ze-ren

2013-08-01

76

Total Dose Effects on Single Event Transients in Digital CMOS and Linear Bipolar Circuits  

NASA Technical Reports Server (NTRS)

This presentation discusses the effects of ionizing radiation on single event transients (SETs) in circuits. The exposure of integrated circuits to ionizing radiation changes electrical parameters. The total ionizing dose effect is observed in both complementary metal-oxide-semiconductor (CMOS) and bipolar circuits. In bipolar circuits, transistors exhibit grain degradation, while in CMOS circuits, transistors exhibit threshold voltage shifts. Changes in electrical parameters can cause changes in single event upset(SEU)/SET rates. Depending on the effect, the rates may increase or decrease. Therefore, measures taken for SEU/SET mitigation might work at the beginning of a mission but not at the end following TID exposure. The effect of TID on SET rates should be considered if SETs cannot be tolerated.

Buchner, S.; McMorrow, D.; Sibley, M.; Eaton, P.; Mavis, D.; Dusseau, L.; Roche, N. J-H.; Bernard, M.

2009-01-01

77

Analysis of current transients in SRAM memories for single event upset detection  

NASA Astrophysics Data System (ADS)

Soft errors resulting from the impact of charged particles are emerging as a major issue in the design of reliable circuits at deep sub-micron dimensions even at ground level. To face this challenge, a designer must dispose of a variety of mitigation schemes adapted to their specific design constraints. Built In Current Sensors have been proposed as a detection scheme for single event upsets in SRAM. In this paper, Power-Bus current transients in SRAM memories for Single Event Upset Detection have been analyzed in a 65nm CMOS technology. The different types of current roles which are applied during the simulation is discussed. The results show the important contribution of leakage currents in the response of the memory cell to an external event.

Torrens, G.; Bota, S.; Verd, J.; Alorda, B.; Merino, J.; Segura, J.

2009-05-01

78

Transient pressure testing of fractured water injection wells  

Microsoft Academic Search

This paper describes the application of pressure falloff tests in fractured water injection wells to determine fracture lengths and fracture opening pressures. An improved method of calculating fracture lengths from pressure falloff test data is presented. This method is based on a linear flow model which simulates conditions present during the early time period after shutting in an injection well.

1967-01-01

79

Structural analysis of fuel assembly clads for the Upgraded Transient Reactor Test Facility (TREAT Upgrade)  

SciTech Connect

The Upgraded Transient Reactor Test Facility (TREAT Upgrade) is designed to test full-length, pre-irradiated fuel pins of the type used in large LMFBRs under accident conditions, such as severe transient overpower and loss-of-coolant accidents. In TREAT Upgrade, the central core region is to contain new fuel assemblies of higher fissile loadings to maximize the energy deposition to the test fuel. These fuel assemblies must withstand normal peak clad temperatures of 850/sup 0/C for hundreds of test transients. Due to high temperatures and gradients predicted in the clad, creep and plastic strain effects are significant, and the clad structural behavior cannot be analyzed by conventional linear techniques. Instead, the detailed elastic-plastic-creep behavior must be followed along the time-dependent load history. This paper presents details of the structural evaluations of the conceptual TREAT Upgrade fuel assembly clads.

Ewing, T.F.; Wu, T.S.

1986-01-01

80

Transient excitation boosting at Grand Coulee third power plant: Power system application and field tests  

SciTech Connect

Transient excitation boosting (TEB) has been installed on the Grand Coulee Third Power Plant hydrogenerators (three 600 MVA units and three 700 MVA units). TEB is initiated for outages of the 3100 MW Pacific HVDC Intertie, and results in a decaying pulse input to the generator voltage regulators. TEB temporarily raises Pacific Northwest transmission voltages which increases voltage-sensitive loads. The increased load brakes Northwest generators which are accelerating because of the loss of HVDC Intertie power. Transient stability of the parallel Pacific AC Intertie is thus improved. Power system-wide commissioning tests were conducted on May 7, 1991. The authors describe the tests and compare test results with simulation results.

Taylor, C.W.; Mechenbier, J.R.; Matthews, C.E. (Bonneville Power Administration, Portland, OR (United States))

1993-08-01

81

A chassis test procedure to mimic the heavy-duty engine transient emissions certification test.  

PubMed

In-use emissions from vehicles using heavy-duty diesel engines can be significantly higher than the levels obtained during engine certification. These higher levels may be caused by a combination of degradation of engine components, poor engine maintenance, degradation or failure of emissions after-treatment devices, and engine and emissions system tampering. A direct comparison of in-use vehicle emissions with engine certification levels, however, is not possible without removing an engine from the vehicle in order to perform engine dynamometer emissions testing. The goal of this research was to develop a chassis test procedure that mimics the engine performance, and as such the expected emissions levels, from the engine certification emissions test prescribed in the U.S. Code of Federal Regulations. Emissions measurements were taken from two engines during testing on an engine dynamometer using the transient heavy-duty Federal Test Procedure (FTP). Additionally, each engine was installed in an appropriate vehicle, and emissions measurements were taken using a chassis dynamometer while employing a vehicle driving schedule intended to match closely the instantaneous torque and speed schedule of the engine FTP. Engine and chassis testing was performed with the engines in stock (unmodified) condition as well as in several modes to simulate either tampered or poorly maintained conditions. The use of a chassis test as a predictive tool for determining whether an engine in a vehicle would pass the engine certification test has proven to be worthwhile. Analysis of the data shows that identification of chassis-mounted engines with NOx emissions above certification levels is possible by employing engine-specific correction factors. In the case of PM emissions, significant data scatter allowed only the identification of gross PM emitters. Engine tampering and poor maintenance can raise PM and NOx emissions, and these increases can be correctly identified by a chassis test. Analysis of chassis and engine CO and HC emissions did not reveal a strong enough correlation to warrant the use of the chassis test for emissions screening of these two pollutants. PMID:11266106

Clark, N N; McKain, D L

2001-03-01

82

40 CFR 86.1333-90 - Transient test cycle generation.  

Code of Federal Regulations, 2013 CFR

...test. The torque and rpm feedback signals may be filtered. (d) Idle Speed Enhancement Devices (e.g. cold idle, alternator idle, etc.). For an engine equipped with an idle speed enhancement device, the zero percent speed specified in...

2013-07-01

83

Exciton dynamics in single-walled nanotubes:?Transient photoinduced dichroism and polarized emission  

NASA Astrophysics Data System (ADS)

Ultrafast relaxation of photoexcitations in semiconducting single-walled carbon nanotubes ( S -NTs) were investigated using polarized pump-probe photomodulation (with 150 fs time resolution) and cw polarized photoluminescence (PL). Both annealed and unannealed thin NT films and D2O solutions of isolated NTs were investigated. Various transient photoinduced bleaching (PB) and photoinduced absorption (PA) bands, which show photoinduced dichroism, were observed in the ultrafast photomodulation spectra of all NT forms. The PA and PB decay dynamics as a function of time, t , follow a power law, (t)-? with ? in the range of 0.7 to 1. Whereas the PA bands in S -NTs in solution uniformly decay, the PB bands, in contrast, have different decay dynamics across the spectrum, which originates from an ultrafast spectral shift. Nevertheless the dynamics of the PA and PB bands for NTs in solution are the same when the spectral shift is accounted for, indicating a common origin. In addition S -NTs in D2O solution show polarized PL emission bands in the mid infrared spectral range that follow almost exactly the infrared absorption peaks of the isolated NTs, as well as their transient PB spectrum. The PL emission shows a degree of polarization that agrees with that of the transient photoinduced dichroism. We therefore conclude that the primary photoexcitations in S -NTs are not free carriers, rather they are excitons that are confined along the nanotubes. We found that the transient relaxation kinetics of the excitons depend on the NT form. The fastest exciton dynamics (with sub-picosecond lifetime) characterizes the annealed film, whereas the slowest dynamics (with lifetime of tens of ps) characterizes the isolated NTs in D2O solution. From the polarization memory decay we could estimate the diffusion constant, D , and the diffusion length, LD , of the excitons along the nanotube. For the annealed films at room temperature we found D?100cm2s-1 and LD?100nm . From the average PL polarization degree, which remains constant across the PL spectrum, and the transient polarization memory decay, we estimate the PL lifetime in NT solution to be of the order of 500 ps. This relatively long PL lifetime is dominated by nonradiative decay processes, which when coupled with the minute PL emission quantum efficiency indicates a very small radiative recombination rate. The weak radiative transition strength is consistent with recent excited state calculations that include electron-hole interaction, which predict that excitons in NTs are basically dark.

Sheng, C.-X.; Vardeny, Z. V.; Dalton, A. B.; Baughman, R. H.

2005-03-01

84

Evaluation report of the unit load transient test results for YGN 4.  

National Technical Information Service (NTIS)

This report summarizes the information which was acquired from results of unit load transient test performed during YGN 4 power ascension test. The purpose of this report is to provide actual field information to the engineers who are involved in the nucl...

S. H. Sohn W. S. Jeong H. T. Seo J. T. Seo

1996-01-01

85

Evaluation report of the unit load transient test results for YGN 3.  

National Technical Information Service (NTIS)

This report summarizes the information which was acquired from results of unit load transient test performed during YGN 3 power ascension test. The purpose of this report is to provide actual field information to the engineers who are involved in the nucl...

S. H. Sohn W. S. Jeong H. T. Seo J. T. Seo

1996-01-01

86

Transient thermography testing of unpainted thermal barrier coating surfaces  

NASA Astrophysics Data System (ADS)

This paper has investigated the effects of uneven surface discolouration of a thermal barrier coating (TBC) and of its IR translucency on the thermal responses observed by using mid and long wavelength IR cameras. It has been shown that unpainted blades can be tested satisfactorily by using a more powerful flash heating system and a long wavelength IR camera. The problem of uneven surface emissivity can be overcome by applying 2nd derivative processing of the log-log surface cooling curves.

Ptaszek, Grzegorz; Cawley, Peter; Almond, Darryl; Pickering, Simon

2013-01-01

87

Pulsed single-blow regenerator testing  

NASA Technical Reports Server (NTRS)

A pulsed single-blow method has been developed for testing of Stirling regenerator materials performance. The method uses a tubular flow arrangement with a steady gas flow passing through a regenerator matrix sample that packs the flow channel for a short distance. A wire grid heater spanning the gas flow channel is used to heat a plug of gas by approximately 2 K for approximately 350 ms. Foil thermocouples monitor the gas temperature entering and leaving the sample. Data analysis based on a 1D incompressible-flow thermal model allows the extraction of Stanton number. A figure of merit involving heat transfer and pressure drop is used to present results for steel screens and steel felt. The observations show a lower figure of merit for the materials tested than is expected based on correlations obtained by other methods.

Oldson, J. C.; Knowles, T. R.; Rauch, J.

1992-01-01

88

Vibrational response of free standing single copper nanowire through transient reflectivity microscopy  

NASA Astrophysics Data System (ADS)

We report on the ultrafast vibrational response of single copper nanowires investigated by femtosecond transient reflectivity measurements. The oscillations of the sample reflectivity are correlated with individual modes of resonance for wires with a diameter ranging from 100 to 500 nm and are compared with 2D finite element simulation. Fluctuation of the sample-substrate coupling is illustrated through its effect on the damping rate. We demonstrate elastic confinement in free standing wires which allowed the detection of up to the third harmonic of the breathing mode. By removing the energy relaxation channel towards the substrate, we obtained nano-oscillators with quality factors up to 130. Finally, taking advantage of the very high spectral resolution achieved on free standing wires, we could observe the elastic coupling between two close wires via their polymer cladding.

Belliard, Laurent; Cornelius, Thomas W.; Perrin, Bernard; Kacemi, Nazim; Becerra, Loïc; Thomas, Olivier; Eugenia Toimil-Molares, Maria; Cassinelli, Marco

2013-11-01

89

PHASE I SINGLE CELL ELECTROLYZER TEST RESULTS  

SciTech Connect

This document reports the results of Phase I Single Cell testing of an SO{sub 2}-Depolarized Water Electrolyzer. Testing was performed primarily during the first quarter of FY 2008 at the Savannah River National Laboratory (SRNL) using an electrolyzer cell designed and built at SRNL. Other facility hardware were also designed and built at SRNL. This test further advances this technology for which work began at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The focus of this work was to conduct single cell electrolyzer tests to further develop the technology of SO{sub 2}-depolarized electrolysis as part of the HyS Cycle. The HyS Cycle is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen and regenerate sulfur dioxide. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Low cell voltage is essential for both thermodynamic efficiency and hydrogen cost. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the high temperature acid decomposition portion of the cycle. The electrolyzer cell uses the membrane electrode assembly (MEA) concept. The anode and cathode are formed by spraying platinum containing catalyst on both sides of a Proton Exchange Membrane (PEM). In most testing the material of the PEM was NafionR. The electrolyzer cell active area can be as large as 54.8 cm{sup 2}. Feed to the anode of the electrolyzer is a sulfuric acid solution containing sulfur dioxide. The partial pressure of sulfur dioxide could be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures could be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell was collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to operate, versatile, and reliable.

Steimke, J; Timothy Steeper, T

2008-08-05

90

Transient Testing of Nuclear Fuels and Materials in the United States  

NASA Astrophysics Data System (ADS)

The United States has established that transient irradiation testing is needed to support advanced light water reactors fuel development. The U.S. Department of Energy (DOE) has initiated an effort to reestablish this capability. Restart of the Transient Testing Reactor (TREAT) facility located at the Idaho National Laboratory (INL) is being considered for this purpose. This effort would also include the development of specialized test vehicles to support stagnant capsule and flowing loop tests as well as the enhancement of postirradiation examination capabilities and remote device assembly capabilities at the Hot Fuel Examination Facility. It is anticipated that the capability will be available to support testing by 2018, as required to meet the DOE goals for the development of accident-tolerant LWR fuel designs.

Wachs, Daniel M.

2012-12-01

91

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

2013-10-01

92

APOBEC3A deaminates transiently exposed single-strand DNA during LINE-1 retrotransposition  

PubMed Central

Long INterspersed Element-1 (LINE-1 or L1) retrotransposition poses a mutagenic threat to human genomes. Human cells have therefore evolved strategies to regulate L1 retrotransposition. The APOBEC3 (A3) gene family consists of seven enzymes that catalyze deamination of cytidine nucleotides to uridine nucleotides (C-to-U) in single-strand DNA substrates. Among these enzymes, APOBEC3A (A3A) is the most potent inhibitor of L1 retrotransposition in cultured cell assays. However, previous characterization of L1 retrotransposition events generated in the presence of A3A did not yield evidence of deamination. Thus, the molecular mechanism by which A3A inhibits L1 retrotransposition has remained enigmatic. Here, we have used in vitro and in vivo assays to demonstrate that A3A can inhibit L1 retrotransposition by deaminating transiently exposed single-strand DNA that arises during the process of L1 integration. These data provide a mechanistic explanation of how the A3A cytidine deaminase protein can inhibit L1 retrotransposition. DOI: http://dx.doi.org/10.7554/eLife.02008.001

Richardson, Sandra R; Narvaiza, Inigo; Planegger, Randy A; Weitzman, Matthew D; Moran, John V

2014-01-01

93

Transient excitation and mechanical admittance test techniques for prediction of payload vibration environments  

NASA Technical Reports Server (NTRS)

Transient excitation forces were applied separately to simple beam-and-mass launch vehicle and payload models to develop complex admittance functions for the interface and other appropriate points on the structures. These measured admittances were then analytically combined by a matrix representation to obtain a description of the coupled system dynamic characteristics. Response of the payload model to excitation of the launch vehicle model was predicted and compared with results measured on the combined models. These results are also compared with results of earlier work in which a similar procedure was employed except that steady-state sinusoidal excitation techniques were included. It is found that the method employing transient tests produces results that are better overall than the steady state methods. Furthermore, the transient method requires far less time to implement, and provides far better resolution in the data. However, the data acquisition and handling problem is more complex for this method. It is concluded that the transient test and admittance matrix prediction method can be a valuable tool for development of payload vibration tests.

Kana, D. D.; Vargas, L. M.

1977-01-01

94

Transient oxidative stress and inflammation after intraperitoneal administration of multiwalled carbon nanotubes functionalized with single strand DNA in rats  

SciTech Connect

Multi-walled carbon nanotubes (MWCNTs) are widely used for nanotechnology. Their impact on living organisms is, however, not entirely clarified. Oxidative stress and inflammation seem to be the key mechanisms involved in MWCNTs' cytotoxicity. Until present, pulmonary and skin models were the main tested experimental designs to assess carbon nanotubes' toxicity. The systemic administration of MWCNTs is essential, with respect for future medical applications. Our research is performed on Wistar rats and is focused on the dynamics of oxidative stress parameters in blood and liver and pro-inflammatory cytokines in liver, after single dose (270 mg l{sup ?1}) ip administration of MWCNTs (exterior diameter 15–25 nm, interior diameter 10–15 nm, surface 88 m{sup 2} g{sup ?1}) functionalized with single strand DNA (ss-DNA). The presence of MWCNTs in blood was assessed by Raman spectroscopy, while in liver histological examination and confocal microscopy were used. It was found that ss-DNA-MWCNTs induce oxidative stress in plasma and liver, with the return of the tested parameters to normal values, 6 h after ip injection of nanotubes, with the exception of reduced glutathione in plasma. The inflammatory cytokines (TNF-?, IL-1?) had a similar pattern of evolution. We also assessed the level of ERK1/2 and the phosphorylation of p65 subunit of NF-kB in liver that had a transient increase and returned to normal at the end of the tested period. Our results demonstrate that ss-DNA-MWCNTs produce oxidative stress and inflammation, but with a transient pattern. Given the fact that antioxidants modify the profile not only for oxidative stress, but also of inflammation, the dynamics of these alterations may be of practical importance for future protective strategies. -- Highlights: ? ss-DNA-MWCNTs ip administration induce oxidative stress in plasma and liver. ? ss-DNA-MWCNTs ip administration determine liver inflammation. ? ERK1/2 and p65 phosphorylated NF-KB increase in liver after MWCNTs ip injection. ? All the alterations, except plasma GSH, return to normal within 6 days.

Clichici, Simona, E-mail: simonaclichici@yahoo.com [Department of Physiology, University of Medicine and Pharmacy, Cluj-Napoca (Romania)] [Department of Physiology, University of Medicine and Pharmacy, Cluj-Napoca (Romania); Biris, Alexandru Radu [National R and D Institute of Isotopic and Molecular Technologies, Cluj-Napoca (Romania)] [National R and D Institute of Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Tabaran, Flaviu [University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca (Romania)] [University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca (Romania); Filip, Adriana [Department of Physiology, University of Medicine and Pharmacy, Cluj-Napoca (Romania)] [Department of Physiology, University of Medicine and Pharmacy, Cluj-Napoca (Romania)

2012-03-15

95

History-Dependent Excitability as a Single-Cell Substrate of Transient Memory for Information Discrimination  

PubMed Central

Neurons react differently to incoming stimuli depending upon their previous history of stimulation. This property can be considered as a single-cell substrate for transient memory, or context-dependent information processing: depending upon the current context that the neuron “sees” through the subset of the network impinging on it in the immediate past, the same synaptic event can evoke a postsynaptic spike or just a subthreshold depolarization. We propose a formal definition of History-Dependent Excitability (HDE) as a measure of the propensity to firing in any moment in time, linking the subthreshold history-dependent dynamics with spike generation. This definition allows the quantitative assessment of the intrinsic memory for different single-neuron dynamics and input statistics. We illustrate the concept of HDE by considering two general dynamical mechanisms: the passive behavior of an Integrate and Fire (IF) neuron, and the inductive behavior of a Generalized Integrate and Fire (GIF) neuron with subthreshold damped oscillations. This framework allows us to characterize the sensitivity of different model neurons to the detailed temporal structure of incoming stimuli. While a neuron with intrinsic oscillations discriminates equally well between input trains with the same or different frequency, a passive neuron discriminates better between inputs with different frequencies. This suggests that passive neurons are better suited to rate-based computation, while neurons with subthreshold oscillations are advantageous in a temporal coding scheme. We also address the influence of intrinsic properties in single-cell processing as a function of input statistics, and show that intrinsic oscillations enhance discrimination sensitivity at high input rates. Finally, we discuss how the recognition of these cell-specific discrimination properties might further our understanding of neuronal network computations and their relationships to the distribution and functional connectivity of different neuronal types.

Baroni, Fabiano; Torres, Joaquin J.; Varona, Pablo

2010-01-01

96

Single cycle and transient force measurements in dynamic atomic force microscopy.  

PubMed

The monitoring of the deflection of a micro-cantilever, as the end of a sharp probe mounted at its end, i.e. the tip, interacts with a surface, forms the foundation of atomic force microscopy AFM. In a nutshell, developments in the field are driven by the requirement of obtaining ever increasing throughput and sensitivity, and enhancing the versatility of the instrument to simultaneously map the topography and quantify nanoscale processes and properties. In the most common dynamic mode of operation, the motion of the driven cantilever is monitored at a single point on its longitudinal axis. Here, we show that from this single point a waveform is obtained that contains all the details about conservative and dissipative interactions. Then a formalism that accounts for multiple arbitrary flexural modes is developed for an indirectly driven cantilever. The formalism is shown to allow recovery of the details of the interaction even in the presence of complex and relevant hysteretic forces when the cantilever oscillates in the steady state. In a different approach, we develop a formalism that monitors the wave profile of the cantilever, i.e. the waveform at five different points on its longitudinal axis. With this formalism the interaction can be reconstructed during a single oscillation cycle even in the transient state of oscillation. Finally, we discuss the potential and advantages of the proposed methods and future technical challenges. Other standard and state of the art techniques and methods are also discussed and compared with the ones presented here. This work should also provide insight into the current high throughput-high sensitivity developments dealing with multifrequency dynamic AFM where information is recovered from multiple eigenmodes. PMID:24071898

Gadelrab, Karim; Santos, Sergio; Font, Josep; Chiesa, Matteo

2013-11-21

97

Single cycle and transient force measurements in dynamic atomic force microscopy  

NASA Astrophysics Data System (ADS)

The monitoring of the deflection of a micro-cantilever, as the end of a sharp probe mounted at its end, i.e. the tip, interacts with a surface, forms the foundation of atomic force microscopy AFM. In a nutshell, developments in the field are driven by the requirement of obtaining ever increasing throughput and sensitivity, and enhancing the versatility of the instrument to simultaneously map the topography and quantify nanoscale processes and properties. In the most common dynamic mode of operation, the motion of the driven cantilever is monitored at a single point on its longitudinal axis. Here, we show that from this single point a waveform is obtained that contains all the details about conservative and dissipative interactions. Then a formalism that accounts for multiple arbitrary flexural modes is developed for an indirectly driven cantilever. The formalism is shown to allow recovery of the details of the interaction even in the presence of complex and relevant hysteretic forces when the cantilever oscillates in the steady state. In a different approach, we develop a formalism that monitors the wave profile of the cantilever, i.e. the waveform at five different points on its longitudinal axis. With this formalism the interaction can be reconstructed during a single oscillation cycle even in the transient state of oscillation. Finally, we discuss the potential and advantages of the proposed methods and future technical challenges. Other standard and state of the art techniques and methods are also discussed and compared with the ones presented here. This work should also provide insight into the current high throughput-high sensitivity developments dealing with multifrequency dynamic AFM where information is recovered from multiple eigenmodes.

Gadelrab, Karim; Santos, Sergio; Font, Josep; Chiesa, Matteo

2013-10-01

98

49 CFR 238.311 - Single car test.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Single car test. 238.311 Section 238.311 Transportation...Passenger Equipment § 238.311 Single car test. (a) Except for self-propelled passenger cars, single car tests of all passenger...

2013-10-01

99

Measurement of conducted transients on automotive sensors  

Microsoft Academic Search

Honeywell has developed a new concept for high frequency conducted transient measurements at automotive sensor connectors directly on the vehicle using a special interface covering the DC to 18 GHz frequency range. Conducted transients were captured using both a digitizing oscilloscope TDS-794D and HP spectrum analyzer to analyze single event-conducted transients and harmonic content. The objective of the test was

V. Ivanov; M. Plagens

2000-01-01

100

Properties of transient K+ currents and underlying single K+ channels in rat olfactory receptor neurons  

PubMed Central

The transient potassium current, IK(t), of enzymatically dissociated rat olfactory receptor neurons was studied using patch-clamp techniques. Upon depolarization from negative holding potentials, IK(t) activated rapidly and then inactivated with a time course described by the sum of two exponential components with time constants of 22.4 and 143 ms. Single-channel analysis revealed a further small component with a time constant of several seconds. Steady-state inactivation was complete at -20 mV and completely removed at -80 mV (midpoint -45 mV). Activation was significant at -40 mV and appeared to reach a maximum conductance at +40 mV (midpoint -13 mV). Deactivation was described by the sum of two voltage-dependent exponential components. Recovery from inactivation was extraordinarily slow (50 s at -100 mV) and the underlying processes appeared complex. IK(t) was reduced by 4- aminopyridine and tetraethylammonium applied externally. Increasing the external K+ concentration ([K+]o) from 5 to 25 mM partially removed IK(t) inactivation, usually without affecting activation kinetics. The elevated [K+]o also hyperpolarized the steady-state inactivation curve by 9 mV and significantly depolarized the voltage dependence of activation. Single transient K+ channels, with conductances of 17 and 26 pS, were observed in excised patches and often appeared to be localized into large clusters. These channels were similar to IK(t) in their kinetic, pharmacological, and voltage-dependent properties and their inactivation was also subject to modulation by [K+]o. The properties of IK(t) imply a role in action potential repolarization and suggest it may also be important in modulating spike parameters during neuronal burst firing. A simple method is also presented to correct for errors in the measurement of whole-cell resistance (Ro) that can result when patch-clamping very small cells. The analysis revealed a mean corrected Ro of 26 G omega for these cells.

1991-01-01

101

Pressure transient tests on geothermal wells in the Dogger aquifer, Paris Basin  

NASA Astrophysics Data System (ADS)

In this work, we propose a new interpretation of pressure transient tests conducted in more than sixty wells targeting the Dogger formation in the Paris basin. The most part of these wells were drilled during the eighties over a very short period of time in an urban area. The transient tests were only recorded during a pressure buildup and show that contrary to what has long been assumed the Dogger aquifer behavior is not homogeneous. The interpretation of the obtained data was mainly done with Horner's method, independently for each well, and assuming generally that the aquifer is homogeneous. Available data from pressure transient tests are limited because of the precision of the tools used, and because pressure buildup was only recorded during eight to twelve hours. The objective was to determine the average transmissivity and the skin factor in order to obtain the productivity of the wells. We gather all available data, including those obtained on the thirteen recent wells, and propose a new interpretation in terms of aquifer model. We use the pressure derivative method developed in the nineties for oil reservoirs which allows a better visualization of the model and of the heterogeneity of the aquifer. Most of the well tests have a derivative pressure curve with a slope equal to zero, that does not change after the well bore effects, confirming that the aquifer is relatively homogenous. However on a dozen of wells, data from pressure transient tests display singular behaviors that can be related to a double porosity or double permeability model for some wells and to a composite model for others. These observations question the validity of a homogeneous model for the Dogger aquifer in the Paris basin and the currently used parameters for the thermal and hydrodynamic predictive model of geothermal exploitation. Finally, this work increases our understanding of the Dogger aquifer in the Paris basin and will allow the optimization of the ongoing hydraulic tests and the future exploitation of geothermal energy in the area.

giuglaris, elodie; hamm, virginie

2014-05-01

102

Single Event Effects (SEE) Testing of Embedded DSP Cores within Microsemi RTAX4000D Field Programmable Gate Array (FPGA) Devices  

NASA Technical Reports Server (NTRS)

Motivation for this work is: (1) Accurately characterize digital signal processor (DSP) core single-event effect (SEE) behavior (2) Test DSP cores across a large frequency range and across various input conditions (3) Isolate SEE analysis to DSP cores alone (4) Interpret SEE analysis in terms of single-event upsets (SEUs) and single-event transients (SETs) (5) Provide flight missions with accurate estimate of DSP core error rates and error signatures.

Perez, Christopher E.; Berg, Melanie D.; Friendlich, Mark R.

2011-01-01

103

Excited state dynamics of single metal and semiconductor nanowires studied by transient absorption microscopy  

NASA Astrophysics Data System (ADS)

Transient absorption microscopy (TAM) is a relatively new technique that allows the study of single nanostructures with sub-picosecond time resolution. Here, we present results for CdTe and Au Nanowires (NW). For the first material, we find an interesting power dependence of the excited dynamics, suggesting that a trap-filling mechanism is responsible for the observed behaviour. Additionally, acoustic phonons were observed, which were well described using continuum elastic models.footnotetextS. S. Lo et al. ACS Nano, 6, 5274 (2012) Carrier diffusion along these NWs are also reported. In the case of Au NWs, the propagation of surface plasmon polaritons was investigated. The results are in agreement with previous studies performed with fluorescence based techniques.footnotetextB. Wild et al. ACS Nano, 6, 472 (2012)^,footnotetextA. Paul et al. ACS Nano, 6, 8105 (2012) Unlike fluorescence techniques, multiple measurements on the same nanostructures are possible with TAM allowing one-to-one comparisons under different excitation polarizations and environments.

Lo, Shun S.; Shi, Hong Y.; Major, Todd A.; Petchsang, Nattasamon; Huang, Libai; Kuno, Masaru K.; Hartland, Gregory V.

2013-03-01

104

The transient oxidation of single crystal NiAl+Zr. M.S. Thesis. Final Report  

NASA Technical Reports Server (NTRS)

The 800 C oxidation of oriented single crystals of Zr doped beta-NiAl was studied using transmission electron microscopy. The oxide phases and metal-oxide orientation relationships were determined to characterize the transient stages of oxidation prior to the transformation to or formation of alpha-Al2O3. On (001) and (012) metal orientations, NiAl2O4 was the first oxide to form followed by delta-Al2O3 which becomes the predominant oxide phase. All oxides were highly epitaxially related to the metal; the orientation relationships being function of parallel cation close-packed directions in the meta and oxide. On (011) and (111) metal orientations, gamma-Al2O3 became the predominant oxide phase rather than delta-Al2O3, indicating a structural stability from the highly epitaxial oxides. The relative concentration of aluminum in the oxide scales increased with time indicating preferential gamma-or delta-Al2O3 growth. The striking feature common to the orientation relationships is the alignment of 100 m and 110 ox directions, believed to result from the minimal 3 percent mismatch between the corresponding (100)m and (110)ox planes.

Doychak, J. K.

1983-01-01

105

Inelastic transient electrical currents and phonon heating in a single-level quantum dot system  

NASA Astrophysics Data System (ADS)

We present a theoretical study on inelastic transient electrical currents and the effects of phonon heating in a single-level quantum dot system weakly coupled to a localized vibration degree of freedom, using the nonequilibrium Green's function method under the wide-band-limit and the lowest-order-expansion approximations. The energy transfer between electron and phonon systems is evaluated using both approximations, which separately are exact in the limits of the equilibrium state (t < 0) and steady state (t-->?). The time-dependent phonon number, which determines the system temperature and heating effects on the inelastic current, is calculated using a phenomenological method employing the time-dependent power transfer. The two approximations are shown to provide qualitatively similar dynamical behaviors for the system temperature, which can be grouped under two responses: if the energy corresponding to the applied bias voltage is smaller than or equal to the phonon energy, the temperature first increases because of phonon emission, and then decreases because of phonon absorption; alternatively, if the energy corresponding to the bias voltage is larger than the phonon energy, the temperature increases monotonically until a steady state is reached. The total electrical current is suppressed by phonon heating, while heat transferring between dot and environment mitigates the effects of such heating. Furthermore, the relaxation time of the current is extended by phonon scattering and heating.

Liu, Wei; Sasaoka, Kenji; Yamamoto, Takahiro; Tada, Tomofumi; Watanabe, Satoshi

2013-03-01

106

Quantifying transient 3D dynamical phenomena of single mRNA particles in live yeast cell measurements.  

PubMed

Single-particle tracking (SPT) has been extensively used to obtain information about diffusion and directed motion in a wide range of biological applications. Recently, new methods have appeared for obtaining precise (10s of nm) spatial information in three dimensions (3D) with high temporal resolution (measurements obtained every 4 ms), which promise to more accurately sense the true dynamical behavior in the natural 3D cellular environment. Despite the quantitative 3D tracking information, the range of mathematical methods for extracting information about the underlying system has been limited mostly to mean-squared displacement analysis and other techniques not accounting for complex 3D kinetic interactions. There is a great need for new analysis tools aiming to more fully extract the biological information content from in vivo SPT measurements. High-resolution SPT experimental data has enormous potential to objectively scrutinize various proposed mechanistic schemes arising from theoretical biophysics and cell biology. At the same time, methods for rigorously checking the statistical consistency of both model assumptions and estimated parameters against observed experimental data (i.e., goodness-of-fit tests) have not received great attention. We demonstrate methods enabling (1) estimation of the parameters of 3D stochastic differential equation (SDE) models of the underlying dynamics given only one trajectory; and (2) construction of hypothesis tests checking the consistency of the fitted model with the observed trajectory so that extracted parameters are not overinterpreted (the tools are applicable to linear or nonlinear SDEs calibrated from nonstationary time series data). The approach is demonstrated on high-resolution 3D trajectories of single ARG3 mRNA particles in yeast cells in order to show the power of the methods in detecting signatures of transient directed transport. The methods presented are generally relevant to a wide variety of 2D and 3D SPT tracking applications. PMID:24015725

Calderon, Christopher P; Thompson, Michael A; Casolari, Jason M; Paffenroth, Randy C; Moerner, W E

2013-12-12

107

Heat and mass release for some transient fuel source fires: A test report  

SciTech Connect

Nine fire tests using five different trash fuel source packages were conducted by Sandia National Laboratories. This report presents the findings of these tests. Data reported includes heat and mass release rates, total heat and mass release, plume temperatures, and average fuel heat of combustion. These tests were conducted as a part of the US Nuclear Regulatory Commission sponsored fire safety research program. Data from these tests were intended for use in nuclear power plant probabilistic risk assessment fire analyses. The results were also used as input to a fire test program at Sandia investigating the vulnerability of electrical control cabinets to fire. The fuel packages tested were chosen to be representative of small to moderately sized transient trash fuel sources of the type that would be found in a nuclear power plant. The highest fire intensity encountered during these tests was 145 kW. Plume temperatures did not exceed 820/sup 0/C.

Nowlen, S.P.

1986-10-01

108

Compilation of Quality Assurance Documentation for Analyses Performed for the Resumption of Transient Testing Environmental Assessment  

SciTech Connect

This is a companion document to the analyses performed in support of the environmental assessment for the Resumption of Transient Fuels and Materials Testing. It is provided to allow transparency of the supporting calculations. It provides computer code input and output. The basis for the calculations is documented separately in INL (2013) and is referenced, as appropriate. Spreadsheets used to manipulate the code output are not provided.

Annette L. Schafer; A. Jeffrey Sondrup

2013-11-01

109

First TREAT transient overpower tests on U-Pu-Zr fuel: M5 and M6  

SciTech Connect

Transient Reactor Test Facility (TREAT) tests M5 and M6 were the first transient overpower (TOP) test of the margin to cladding breach and prefailure elongation of metallic U-Pu-Zr ternary fuel, the reference fuel of the integral fast reactor concept. Similar tests on U-5 wt% Fs fueled Experimental Breeder Reactor (EBR)-II driver pins were previously performed and reported. Results from these earlier tests indicated a margin to failure of approx. 4 times nominal power and significant axial elongation prior to failure, a feature that was very pronounced at low burnups. While these two fuels types are similar in many respects, the ternary alloy exhibits a much more complex physical structure and is typically irradiated at much higher temperatures. Thus, a prime motivation for performing M5 and M6 was to compare the safety-related fuel performance characteristics of U-Fs and U-Pu-Zr. Tests M5 and M6 indicate that, under the TOP conditions used in the tests, ternary fuel displayed about the same margin to failure as U-Fs fuel. At low burnups, ternary fuel showed less prefailure axial elongation than observed in U-Fs pins, but elongations of 3 to 5% might turn out to be typical. Finally, fuel from the breached ternary pin in M6 showed, qualitatively, the same benignly dispersive behavior as U-Fs.

Robinson, W.R.; Bauer, T.H.; Wright, A.E.; Rhodes, E.A.; Stanford, G.S.; Klickman, A.E.

1987-01-01

110

RAPID Boron-dilution Transient Tests for OECD/CSNI International Standard Problem No. 43  

SciTech Connect

The University of Maryland 2 x 4 Thermalhydraulic Loop Facility (UM 2 x 4 Loop) collected code verification data for rapid boron-dilution (RBD) transients. This paper addresses the objectives of recently completed RBD tests and the redesign of the UM 2 x 4 Loop facility for the four test series of the current program. The UM 2 x 4 Loop facility is described in sufficient detail to permit the preparation of input models for code verification. Initial and boundary conditions are given. The OECD/CSNI International Standard Problem No. 43 (ISP 43) figures of merit for comparison of code predictions to experimental findings are described. Specific values for the most representative figures of merit are given for the two closed test series: injection of a front and injection of a slug without downcomer bypass. Because flow regime is a substantial factor in downcomer mixing for RBD transients, the effect of inertial forces on figures of merit is discussed. Tests with downcomer flowrates that fall below the transition to turbulence are shown to exhibit behaviors different from tests ran at downcomer Reynolds numbers that fall in the turbulent regime. Specifically, it is shown that in high flowrate tests mixing is more vigorous when evaluated from a global perspective, but regions of the slug can remain more segregated from the ambient primary coolant than in slow tests. (authors)

Gavrilas, Mirela [University of Maryland, College Park, MD 20742 (United States); Palazov, Vesselin [ISL Inc., Rockville MD. (United States); Woods, Brian [Dominion Generation, Richmond VA. (United States)

2002-07-01

111

Transient Pressure Test Article (TPTA) 1.1 and 1.1A, volume 1  

NASA Technical Reports Server (NTRS)

This final test report presents the results obtained during the static hot firing and cold-gas high Q tests of the first Transient Pressure Test Article (TPTA) 1.1. The TPTA consisted of field test joints A and B, which were the original RSRM J-insulation configuration, with a metal capture feature. It also consisted of a flight configuration nozzle-to-case test joint (Joint D) with shorter vent slots. Fluorocarbon O-rings were used in all the test joints. The purpose of the TPTA tests is to evaluate and characterize the RSMR field and nozzle-to-case joints under the influence of ignition and strut loads during liftoff anf high Q. All objectives of the cold-gas high Q (TPTA 1.1A) test were met and all measurements were close to predicted values. During the static hot-firing test (TPTA 1.1), the motor was inadvertently plugged by the quench injector plug, making it a more severe test, although no strut loads were applied. The motor was depressurized after approximately 11 min using an auxiliary system, and no anomalies were noted. In the static hot-firing test, pressure was incident on the insulation and the test joint gaps were within the predicted range. During the static hot-firing test, no strut loads were applied because the loading system malfunctioned. For this test, all measurements were within range of similar tests performed without strut loads.

Rebells, Clarence A.

1988-01-01

112

A Task Scheduling Algorithm of Single Processor Parallel Test System  

Microsoft Academic Search

The purpose of this paper is to implement parallel test in the single processor auto test system and to improve the test efficiency with a lower test cost. The main factor that impacts the test efficiency of test system is the performance of the parallel task scheduling algorithm. This paper puts forward a heuristic parallel task scheduling algorithm: scheduling-Q which

Jiajing Zhuo; Chen Meng; Minghu Zou

2007-01-01

113

Proton transport across transient single-file water pores in a lipid membrane studied by molecular dynamics simulations.  

PubMed Central

To test the hypothesis that water pores in a lipid membrane mediate the proton transport, molecular dynamic simulations of a phospholipid membrane, in which the formation of a water pore is induced, are reported. The probability density of such a pore in the membrane was obtained from the free energy of formation of the pore, which was computed from the average force needed to constrain the pore in the membrane. It was found that the free energy of a single file of water molecules spanning the bilayer is 108(+/-10) kJ/mol. From unconstrained molecular dynamic simulations it was further deduced that the nature of the pore is very transient, with a mean lifetime of a few picoseconds. The orientations of water molecules within the pore were also studied, and the spontaneous translocation of a turning defect was observed. The combined data allowed a permeability coefficient for proton permeation across the membrane to be computed, assuming that a suitable orientation of the water molecules in the pore allows protons to permeate the membrane relatively fast by means of a wirelike conductance mechanism. The computed value fits the experimental data only if it is assumed that the entry of the proton into the pore is not rate limiting. Images FIGURE 1 FIGURE 2 FIGURE 3

Marrink, S J; Jahnig, F; Berendsen, H J

1996-01-01

114

Single-event-transient effects in sub-70 nm bulk and SOI FinFETs  

NASA Astrophysics Data System (ADS)

After fourteen years of research and investigations by engineers in the university and industry communities, FinFET devices are finally ready to use in products [1-2]. FinFET technologies have been demonstrated to outperform planar technologies for high speed, low power and high performance applications, while maintaining the shrinking trends of microelectronics (beyond 32 nm) for at least the next two to three technology generations. These promising findings were enough for leading chip manufacturers like Intel to announce their plans to mass-produce FinFETs in the near future [3-4]. However, the device response in extreme environments (i.e., space) is still not well understood. Exploring the behavior of FinFETs in such environments is also important for the aerospace and medical industries, where unhardened commercial off the shelf (COTS) electronics are used. The objective of this work is to explore the transient electrical behavior of FinFET devices in both bulk and SOI technologies in radiation-rich environments through laser and heavy ion testing. A further objective of this work is to contribute to improving the performance of FinFET devices, in particular in harsh environments. Indeed, the new results obtained in this work identify the physical regions in the devices that are most sensitive to radiation effects and how they affect the radiation response. The findings will help engineers to design new generations of FinFET devices with higher tolerance to radiation effects.

El Mamouni, Farah

115

Evaluation of the Transient Hydrologic Source Term for the Cambric Underground Nuclear Test at Frenchman Flat, Nevada test Site  

SciTech Connect

The objective of Phase II HST work is to develop a better understanding of the evolution of the HST for 1,000 years at the CAMBRIC underground nuclear test site in Frenchman Flat at the NTS. This work provides a better understanding of activities as they actually occurred, incorporates improvements based on recent data acquisition, and provides a basis to use the CAMBRIC site for model validation and monitoring activities as required by the UGTA Project. CAMBRIC was the only test in Frenchman Flat detonated under the water table and best represents a fully saturated environment. These simulations are part of a broad Phase II Frenchman Flat Corrective Action Unit (CAU) flow and transport modeling effort being conducted by the Department of Energy (DOE) Underground Test Area (UGTA) Project. HST simulations provide, either directly or indirectly, the source term used in the CAU model to calculate a contaminant boundary. Work described in this report augments Phase I HST calculations at CAMBRIC conducted by Tompson et al. (1999) and Pawloski et al. (2001). Phase II HST calculations have been organized to calculate source terms under two scenarios: (1) A representation of the transient flow and radionuclide release behavior at the CAMBRIC site that is more specific than Tompson et al. (1999). This model reflects the influence of the background hydraulic gradient, residual test heat, pumping experiment, and ditch recharge, and takes into account improved data sources and modeling approaches developed since the previous efforts. Collectively, this approach will be referred to as the transient CAMBRIC source term. This report describes the development of the transient CAMBRIC HST. (2) A generic release model made under steady-state flow conditions, in the absence of any transient effects, at the same site with the same radiologic source term. This model is for use in the development of simpler release models for the other nine underground test sites in the Frenchman Flat CAU. This approach will be referred to as the steady-state (non-transient) CAMBRIC source term. This work is described in a separate report (Tompson et al., 2005).

Carle, S F; Maxwell, R M; Pawloski, G A; Shumaker, D E; Tompson, A B; Zavarin, M

2006-12-12

116

An infrastructure for accurate characterization of single-event transients in digital circuits?  

PubMed Central

We present the architecture and a detailed pre-fabrication analysis of a digital measurement ASIC facilitating long-term irradiation experiments of basic asynchronous circuits, which also demonstrates the suitability of the general approach for obtaining accurate radiation failure models developed in our FATAL project. Our ASIC design combines radiation targets like Muller C-elements and elastic pipelines as well as standard combinational gates and flip-flops with an elaborate on-chip measurement infrastructure. Major architectural challenges result from the fact that the latter must operate reliably under the same radiation conditions the target circuits are exposed to, without wasting precious die area for a rad-hard design. A measurement architecture based on multiple non-rad-hard counters is used, which we show to be resilient against double faults, as well as many triple and even higher-multiplicity faults. The design evaluation is done by means of comprehensive fault injection experiments, which are based on detailed Spice models of the target circuits in conjunction with a standard double-exponential current injection model for single-event transients (SET). To be as accurate as possible, the parameters of this current model have been aligned with results obtained from 3D device simulation models, which have in turn been validated and calibrated using micro-beam radiation experiments at the GSI in Darmstadt, Germany. For the latter, target circuits instrumented with high-speed sense amplifiers have been used for analog SET recording. Together with a probabilistic analysis of the sustainable particle flow rates, based on a detailed area analysis and experimental cross-section data, we can conclude that the proposed architecture will indeed sustain significant target hit rates, without exceeding the resilience bound of the measurement infrastructure.

Savulimedu Veeravalli, Varadan; Polzer, Thomas; Schmid, Ulrich; Steininger, Andreas; Hofbauer, Michael; Schweiger, Kurt; Dietrich, Horst; Schneider-Hornstein, Kerstin; Zimmermann, Horst; Voss, Kay-Obbe; Merk, Bruno; Hajek, Michael

2013-01-01

117

Prototypical steam generator (MB-2) transient testing program. Task plan/scaling analysis report. [PWR  

SciTech Connect

This report describes the Westinghouse MB-2 model boiler test facility and the test program currently planned (with Westinghouse/EPRI/NRC funding) to investigate various types of possible accidents which might occur in a PWR steam generator. The planned tests will simulate loss of feedwater (LOF) transients, various steam generator tube rupture (SGTR) scenarios, and steamline breaks (SLB). The facility will be extensively modified to allow measurement of local wall and fluid temperatures, and to measure possible moisture carryover during the SLB and SGTR tests. This report is divided into six sections. The first three sections describe the facility and the new components and instrumentation to be installed. The next section is a detailed scaling analysis of MB-2. Section 5 describes the background and objectives of the tests, and section 6 describes the analysis of the data which if planned.

Young, M.Y.; Takeuchi, K.; Mendler, O.J.; Hopkins, G.W.

1984-03-01

118

Evaluation of naturally fractured gas shale production utilizing multiwell transient tests: A field study  

SciTech Connect

A series of multiple well transient tests were conducted in a Devonian shale gas field in Meigs County, Ohio. Production parameters were quantified and it was determined that the reservoir is highly anisotropic, which is a significant factor in calculating half-fracture length from pressure transient data. Three stimulation treatments, including conventional explosive shooting, nitrogen foam frac, and high energy gas frac (HEGF), were compared on the basis of overall effectiveness and performance. Based on the evaluation of results, the nitrogen foam frac provided the most improved productivity. The study provided new type curves and analytical solutions for the mathematical representation of naturally fractured reservoirs and confirmed that the shale reservoir in Meigs County can be modeled as a dual porosity system using pseudosteady-state gas transfer from the matrix to the fracture system.

Chen, C.C.; Alam, J.; Blanton, T.L.; Vozniak, J.P.

1984-05-01

119

Transient aphasia: a rare complication of head-up tilt test.  

PubMed

Head-up tilt test (HUT) is widely used as a diagnostic tool. It reproduces vasovagal attacks in many susceptible patients. Although it is known to be safe and well tolerated, it is a procedure with potential neurologic complications. We observed that it could cause transient aphasia in some patients. To explore clinical characteristics and possible pathogenesis of aphasia induced by HUT, we reviewed the data of patients undergoing HUT in our hospital. 13 patients experienced transient aphasia in 3,488 cases. According to the hemodynamic changes, the incidence in vasodepressor, mixed, cardioinhibition and the negative response were 6.67, 5.52, 0 and 1.14 ‰ orderly, and not significantly different among the groups. It had significant difference between the positive response and the negative response and between vasodepressor and the negative response (both p < 0.05). The incidence in adults was significantly higher than that in children (<18 years) (p < 0.01), but not different between female and male. The average onset time was 11.33 ± 6.66 min (range 4-17 min) during baseline HUT or 4.90 ± 2.69 min (range 2-10 min) during sublingual nitroglycerin-provocated HUT. The duration was 3-60 min, except for one who was completely relieved of the disorder 4 h later. In conclusions, there is a risk of provoking transient aphasia during HUT. It reminds that performer should alert the possibility of transient aphasia during the test, especially when the patient is an adult and has a positive response. PMID:24514919

Chu, Weihong; Wang, Cheng; Lin, Ping; Li, Fang; Wu, Lijia; Xie, Zhenwu

2014-07-01

120

Transient Response of Charge Collection by Single Ion Strike in 4H-SiC MESFETs  

Microsoft Academic Search

The radiation damage of 4H-SiC Metal Semiconductor Field Effect Transistors (MESFETs) due to gamma rays was studied. The threshold voltage and Schottky property of gate contact varied only slightly after absorbed dose of 10.4 MGy(SiC). In addition, the transient response of charge collection was studied by using transient ion beam induced current (TIBIC) system. It was found that the collected

Shinobu Onoda; Naoya Iwamoto; Shuich Ono; Shuji Katakami; Manabu Arai; Katsuyasu Kawano; Takeshi Ohshima

2009-01-01

121

Assessing the impact of the space radiation environment on parametric degradation and single-event transients in optocouplers  

Microsoft Academic Search

Assessing the risk of using optocouplers in satellite applications offers challenges that incorporate those of commercial off-the-shelf devices compounded by hybrid module construction techniques. We discuss approaches for estimating this risk. In the process, we benchmark our estimates for proton and heavy-ion induced single-event transient rate estimates with recent flight data from the Terra mission. For parametric degradation, we discuss

Robert A. Reed; Christian Poivey; Paul W. Marshall; Kenneth A. LaBel; Cheryl J. Marshall; Scott Kniffin; Janet L. Barth; Christina Seidleck

2001-01-01

122

IM240 Transient I/M Dynamometer Driving Schedule and the Composite I/M Test Procedure.  

National Technical Information Service (NTIS)

Changes in motor vehicle technology have created the need for more sophisticated Inspection and Maintenance tests. In response to this need, the Environmental Protection Agency Motor Vehicle Emission Laboratory has developed the IM240, a short transient t...

W. M. Pidgeon N. Dobie

1991-01-01

123

Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program.  

National Technical Information Service (NTIS)

This document contains the analysis details and summary of analyses conducted to evaluate the environmental impacts for the Resumption of Transient Fuel and Materials Testing Program. It provides an assessment of the impacts for the two action alternative...

2013-01-01

124

Testing of the Euratom LCT coil in the toroidal arrangement of the International Fusion Superconducting Magnet Test Facility without external pulsed fields (standard-I) and with them (standard II) and an extended single-coil test  

Microsoft Academic Search

Testing of the European LCT coil, a forced-flow NbTi coil, with the five other coils in the International Fusion Superconducting Magnet Test Facility (IFSMTF) has been in progress since the beginning of 1986. By the end of July 1987, the Euratom-LCT coil had passed a single-coil test, a test in toroidal configuration with and without poloidal field transients, and an

G. Friesinger; S. Gauss; P. Komarek; M. S. Lubell; T. J. McManamy; W. Maurer; S. S. Shen; L. Siewerdt; A. Ulbricht; F. Wuchner; G. Zahn

1988-01-01

125

The Use of Randomization Tests in Single-Subject Research  

ERIC Educational Resources Information Center

Some researchers have argued for the use of or have attempted to make use of randomization tests in single-subject research. To address this tide of interest, the authors of this article describe randomization tests, discuss the theoretical rationale for applying them to single-subject research, and provide an overview of the methodological…

Haardorfer, Regine; Gagne, Phill

2010-01-01

126

The Use of Randomization Tests in Single-Subject Research  

Microsoft Academic Search

Some researchers have argued for the use of or have attempted to make use of randomization tests in single-subject research. To address this tide of interest, the authors of this article describe randomization tests, discuss the theoretical rationale for applying them to single-subject research, and provide an overview of the methodological research into the Type I error rates and statistical

Regine Haardörfer; Phill Gagné

2010-01-01

127

Large transient fault current test of an electrical roll ring. [for Space Station Freedom  

NASA Technical Reports Server (NTRS)

The Space Station Freedom uses precision rotary gimbals to provide for sun tracking of its photoelectric arrays. Electrical power, command signals, and data are transferred across the gimbals by roll rings. Roll rings have been shown to be capable of highly efficient electrical transmission and long life, through tests conducted at the NASA Lewis Research Center and Honeywell's Satellite and Space Systems Division in Phoenix, AZ. Large potential fault currents inherent to the power system's DC distribution architecture have brought about the need to evaluate the effects of large transient fault currents on roll rings. A test recently conducted at Lewis subjected a roll ring to a simulated worst case space station electrical fault. The system model used to obtain the fault profile is described, along with details of the reduced order circuit that was used to simulate the fault. Test results comparing roll ring performance before and after the fault are also presented.

Yenni, Edward J.; Birchenough, Arthur G.

1991-01-01

128

Improved transient and steady state voltage regulation for single and three phase uninterruptible power supplies  

Microsoft Academic Search

Most of the many reported control algorithms for uninterruptible power supplies use either filter inductor or filter capacitor currents as feedback variables to regulate the output voltage. This paper explores the fundamental performance issues associated with the use of these quantities as feedback variables, with a view to determining their contribution to the transient system response in any particular situation.

P. C. Loh; M. J. Newman; D. N. Zmood; D. G. Holmes

2001-01-01

129

Transient Gas Flow Along Single or Bundled Electrical Cables Surrounded by a Permeable Medium.  

National Technical Information Service (NTIS)

The analysis presented here provides a family of closed-form solutions which can be used to predict the penetration depth of cavity gas as it flows along a cable bundle surrounded by permeable cement. These solutions describe the transient behavior of a l...

R. H. Nilson

1983-01-01

130

Current transients and the Guzik: a case study and methodology for qualifying a spin stand for GMR testing  

Microsoft Academic Search

Repeated dynamic electrical test of current generation anisotropic magnetoresistive (AMR) heads indicated that ESD exposure was likely during test, characterized as a decline in amplitude over time. Giant magnetoresistive (GMR) heads failed catastrophically upon mounting to the Guzik spin stand. By evaluating AMR performance under repeated controlled test sequences, as well as direct current transient measurement techniques, we determined that

Jenny Himle; Roger Bailey; Jeff Hogue; A. Fishman; Robert McKenzie; Terry Porter; Wayne Boone

1998-01-01

131

Barometric Pressure Transient Testing Applications at the Nevada Test Site. Nuclear Chimney Analysis. Final Report.  

National Technical Information Service (NTIS)

Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both histori...

J. M. Hanson

1985-01-01

132

TRAC (Transient Reactor Analysis Code) analyses of Savannah River 1985 L-Area test series  

SciTech Connect

Thermal-hydraulic benchmark analyses have been performed using the Transient Reactor Analysis Code (TRAC) for the Savannah River 1985 L-Area AC process flow tests. TRAC models were prepared and run for each of the 11 L-Area steady-state tests. Comparison of the TRAC results with the Savannah River data focused on coolant pressures and flows in the six external loops as well as the magnitude and distribution of coolant pressures in the upper plenum. In general, the TRAC pressures, pressure drops, and coolant flow rates in the external loops are in reasonable agreement with the data. Moreover, although the TRAC results tend to slightly overpredict the upper- plenum pressure data, the results do provide an excellent representation of the radial and azimuthal variations in upper-plenum pressures. Thus, the 1985 L-Area benchmarks lend credibility and confidence to both TRAC and the TRAC Savannah River plant model. 4 refs., 10 figs., 4 tabs.

Elson, J.S.; Lime, J.F.

1990-01-01

133

Single shaft automotive gas turbine engine characterization test  

NASA Technical Reports Server (NTRS)

An automotive gas turbine incorporating a single stage centrifugal compressor and a single stage radial inflow turbine is described. Among the engine's features is the use of wide range variable geometry at the inlet guide vanes, the compressor diffuser vanes, and the turbine inlet vanes to achieve improved part load fuel economy. The engine was tested to determine its performance in both the variable geometry and equivalent fixed geometry modes. Testing was conducted without the originally designed recuperator. Test results were compared with the predicted performance of the nonrecuperative engine based on existing component rig test maps. Agreement between test results and the computer model was achieved.

Johnson, R. A.

1979-01-01

134

Hanford single shell tank saltcake cesium removal test plan  

SciTech Connect

This document provides the test preparation and conduct of a cesium removal test using Hanford Single Shell Tank Saltcake from tanks 241-BY-110, 241-U-108, 241 U 109, 241-A-101, and 241-S-102 in a benchscale column. The cesium sorbent to be tested is crystalline silicotitanate

Duncan, J.B., Westinghouse Hanford

1996-12-11

135

Implementation details and test results for a transient engine dynamometer and hardware in the loop vehicle model  

Microsoft Academic Search

A state-of-the-art transient dynamometer engine test system has been developed in the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin-Madison. This system includes a hydrostatic dynamometer capable of excitation in excess of 300 Hz, integrated with a controller running the dynamic driveline equations in real time to calculate the instantaneous engine loads during transients. This hardware-in-the-loop (HIL) virtual

Guy R. Babbitt; John J. Moskwa

1999-01-01

136

Engine-in-the-Lo op Testing for Evaluating Hybrid Propulsion Concepts and Transient Emissions - HMMWV Case Study  

Microsoft Academic Search

This paper describes a test cell setup for concurrent running of a real engine and a vehicle system simulation, and its use for evaluating engine performance when integrated with a conventional and a hybrid electric driveline\\/vehicle. This engine-in-the-loop (EIL) system uses fast instruments and emission analyzers to investigate how critical in-vehicle transients affect engine system response and transient emissions. Main

Zoran Filipi; Hosam Fathy; Jonathan Hagena; Alexander Knafl; Rahul Ahlawat; Jinming Liu; Dohoy Jung; Dennis Assanis; Huei Peng; Jeffrey Stein

137

Implementation and Testing of the First Prompt for Electromagnetic Counterparts to Gravitational Wave Transients.  

National Technical Information Service (NTIS)

A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by th...

B. Allen B. P. Abbott C. Adams C. Affeldt D. Amariutei E. Amador Ceron F. Acernese G. S. Allen J. Abadie J. Cannizzo J. B. Camp K. Arai L. Blackburn M. Abernathy M. A. Arain M. C. Araya N. Gehrels P. Ajith R. Abbott R. Adhikari R. S. Amin S. B. Anderson T. Accadia T. D. Abbott W. G. Anderson

2011-01-01

138

Observation of a transient decrease in terahertz conductivity of single-layer graphene induced by ultrafast optical excitation.  

PubMed

We have measured the terahertz frequency-dependent sheet conductivity and its transient response following femtosecond optical excitation for single-layer graphene samples grown by chemical vapor deposition. The conductivity of the unexcited graphene sheet, which was spontaneously doped, showed a strong free-carrier response. The THz conductivity matched a Drude model over the available THz spectral range and yielded an average carrier scattering time of 70 fs. Upon photoexcitation, we observed a transient decrease in graphene conductivity. The THz frequency-dependence of the graphene photoresponse differs from that of the unexcited material but remains compatible with a Drude form. We show that the negative photoconductive response arises from an increase in the carrier scattering rate, with a minor offsetting increase in the Drude weight. This behavior, which differs in sign from that reported previously for epitaxial graphene, is expected for samples with relatively high mobilities and doping levels. The photoinduced conductivity transient has a picosecond lifetime and is associated with nonequilibrium excitation conditions in the graphene. PMID:23330567

Jnawali, Giriraj; Rao, Yi; Yan, Hugen; Heinz, Tony F

2013-02-13

139

Matrix laser vibrometer for transient modal imaging and rapid nondestructive testing  

NASA Astrophysics Data System (ADS)

This article describes the development and application of a 16x16 array (matrix) laser vibrometer based on a parallel architecture which supports fast 2D measurement of arbitrary (steady state, non-steady state, transient) solid body vibrations without beam scanning. The small size and low weight of the measurement probe, which is linked to a remote detector/processor unit via a flexible armoured fibre-optic umbilical, enables deployment in areas with restricted access. Incorporating aspects of high-speed electronic speckle pattern interferometry (ESPI) and laser Doppler vibrometry (LDV), the design is based on a hybrid fiber-optic/bulk optic interferometer which operates at a wavelength of 1550 nm. Test data illustrate high-speed capture of transient vibrations, showing the full 2D temporal evolution of surface deformation, including multiple resonant modes, of a center-pinned metal plate excited by a 1-50 kHz frequency chirp of 109 ms duration. We discuss preliminary data showing detection of sub-surface defects in composite materials, based on non-contact (frequency chirped) acoustic resonance of the locally damaged structure. For large area NDT the probe can be mounted on a lightweight XY gantry for automated multi-frame measurements.

Kilpatrick, James M.; Markov, Vladimir

2008-06-01

140

Use of ruthenium dyes for subnanosecond detector fidelity testing in real time transient absorption  

SciTech Connect

Transient absorption spectroscopy is a powerful tool for the study of photoreactions on time scales from femtoseconds to seconds. Typically, reactions slower than {approx}1 ns are recorded by the ''classical'' technique; the reaction is triggered by an excitation flash, and absorption changes accompanying the reaction are recorded in real time using a continuous monitoring light beam and a detection system with sufficiently fast response. The pico- and femtosecond region can be accessed by the more recent ''pump-probe'' technique, which circumvents the difficulties of real time detection on a subnanosecond time scale. This is paid for by accumulation of an excessively large number of shots to sample the reaction kinetics. Hence, it is of interest to extend the classical real time technique as far as possible to the subnanosecond range. In order to identify and minimize detection artifacts common on a subnanosecond scale, like overshoot, ringing, and signal reflections, rigorous testing is required of how the detection system responds to fast changes of the monitoring light intensity. Here, we introduce a novel method to create standard signals for detector fidelity testing on a time scale from a few picoseconds to tens of nanoseconds. The signals result from polarized measurements of absorption changes upon excitation of ruthenium complexes {l_brace}[Ru(bpy){sub 3}]{sup 2+} and a less symmetric derivative{r_brace} by a short laser flash. Two types of signals can be created depending on the polarization of the monitoring light with respect to that of the excitation flash: a fast steplike bleaching at magic angle and a monoexponentially decaying bleaching for parallel polarizations. The lifetime of the decay can be easily varied via temperature and viscosity of the solvent. The method is applied to test the performance of a newly developed real time transient absorption setup with 300 ps time resolution and high sensitivity.

Byrdin, Martin; Thiagarajan, Viruthachalam; Villette, Sandrine; Espagne, Agathe; Brettel, Klaus [CEA, IBITECS, Laboratoire de Photocatalyse et Biohydrogene, F-91191 Gif-sur-Yvette, France and CNRS, URA 2096, F-91191 Gif-sur-Yvette (France)

2009-04-15

141

TREAT (Transient Reactor Test Facility) reactor control rod scram system simulations and testing  

SciTech Connect

Air cylinders moving heavy components (100 to 300 lbs) at high speeds (above 300 in/sec) present a formidable end-cushion-shock problem. With no speed control, the moving components can reach over 600 in/sec if the air cylinder has a 5 ft stroke. This paper presents an overview of a successful upgrade modification to an existing reactor control rod drive design using a computer model to simulate the modified system performance for system design analysis. This design uses a high speed air cylinder to rapidly insert control rods (278 lb moved 5 ft in less than 300 msec) to scram an air-cooled test reactor. Included is information about the computer models developed to simulate high-speed air cylinder operation and a unique new speed control and end cushion design. A patent application is pending with the US Patent Trade Mark Office for this system (DOE case number S-68,622). The evolution of the design, from computer simulations thru operational testing in a test stand (simulating in-reactor operating conditions) to installation and use in the reactor, is also described. 6 figs.

Solbrig, C.W.; Stevens, W.W.

1990-01-01

142

Single Event Effects Testing of the Linfinity SG1525A Pulse Width Modulator Controller  

NASA Technical Reports Server (NTRS)

Pulse Width Modulator (PWM) Controllers are the heart of switching power supply systems in development today. The PWMs considered here have the same integration advantages as many other controllers but it also includes the interface drivers for the follow-on power Field Effect Transistors (FET). Previous work on these types of devices looked into the required test methodologies [ 11 and the impact of radiation on the soft start and shutdown circuits of typically incorporated in the technology [2]. Taking advantage of this previous work this study was undertaken to determine the single event destructive and transient susceptibility of the Linfinity SG1525A Pulse Width Modulator Controller. The device was monitored for transient interruptions in the output signals and for destructive events induced by exposing it to a heavy ion beam at the Texas A&M University Cyclotron Single Event Effects Test Facility. After exposing these devices to the beam, a new upset mode has been identified that can lead to catastrophic power supply system failure if this event would occur while drive power FETs off the two device outputs. The devices and the test methods used will be described first. This will be followed by a brief description of the data collected to date (not all data can be presented with the length constraints of the summary) and a summary of the key results.

Howard, J. W., Jr.; Carts, M. A.; LaBel, K. A.; Forney, J. D.; Irwin, T. L.

2003-01-01

143

Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations  

NASA Technical Reports Server (NTRS)

The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cu cm. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may be possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.

Woronowicz, M. S.

2010-01-01

144

Heat and Mass Transfer Analysis of Dehumidifiers Using Adiabatic Transient Tests  

SciTech Connect

Adiabatic step transient data were obtained for two dehumidifier test matrices, using parallel plates with crushed silica gel and staggered parallel strips coated with microbead silica gel. The data were analyzed using the statistical moments method and combined heat and mass transfer analogy theory. The analysis showed that the average overall Nusselt number in both matrices was about 40% to 50% lower than laminar flow predictions. The average overall Nusselt number for the microbead staggered matrix was about 85% larger than that of the crushed silica-gel parallel-plate matrix. The Nusselt number/friction factor Reynolds number ratio (Nu/fRe) of the microbead, staggered parallel-strip matrix was about 28% larger than that of the crushed silica-gel parallel-plate matrix. These results were explained by the presence of a stagnant gas film. The results showed that compact, high-performance, rotary dehumidifiers for desiccant cooling systems are possible and economical.

Maclaine-Cross, I. L.; Pesaran, A. A.

1986-04-01

145

Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations  

SciTech Connect

The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cm{sup 3}. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may be possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.

Woronowicz, M. S. [Stinger Ghaffarian Technologies, Inc., 7701 Greenbelt Rd., Greenbelt, Maryland 20770 (United States)

2011-05-20

146

Barometric pressure transient testing applications at the Nevada Test Site. Nuclear chimney analysis. Final report  

SciTech Connect

Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both historical data and new data taken for this current project. An interpretation technique based on non-linear least squares methods was used to analyze this data in terms of historic and more recent chimney models. Finally, a detailed discussion of radioactive gas transport due to surface barometric pressure fluctuations was presented. This mechanism of transport, referred to as ''barometric pumping,'' is presented in terms of conditions likely to be encountered at the NTS. The report concludes with a discussion of the current understanding of gas flow properties in the alluvial and volcanic areas of the NTS, and suggestions for future efforts directed toward increasing this understanding are presented.

Hanson, J.M.

1985-12-01

147

Particle Tracking-Based Strategies For Simulating Transport in a Transient Groundwater Flow Field at Yucca Flat, Nevada Test Site, USA  

NASA Astrophysics Data System (ADS)

Developing probabilistic-based calculations of contaminant concentrations over the next 1000 years at Yucca Flat, Nevada Test site, require tremendous computational effort in this highly complex hydrogeologic surface environment. The sources of contamination, underground nuclear tests conducted between 1951 and 1992, not only released radionuclides to the subsurface but also created abrupt, significant changes in rock properties and caused large transients in the measured hydraulic gradients. To efficiently model contaminant migration from these sources we use a particle-based approach within a transient flow field. Here, we present results using two methods; first, an explicit representation of time-varying sources using large numbers of particles introduced at source-specific rates over time, each representing a unique mass of solute. This method provides good results, but is computationally expensive since sensitivity to uncertainty in source term and transport parameters can only be explored with discrete process-model runs. The second method employs a convolution method (PLUMECALC) which can efficiently consider a large number of variations in the source terms and in certain transport parameters with a single process-model run. Implementation of this second approach required extension of the existing methodology to conditions of transient flow. We find very good comparison between the two methods on small test problems and excellent computational advantages when applying the convolution method in the NTS application

Keating, E. H.; Srinivasan, G.; Kang, Q.; Li, C.; Dash, Z.; Kwicklis, E. M.

2009-12-01

148

Selecting Single Model in Combination Forecasting Based on Cointegration Test and Encompassing Test  

PubMed Central

Combination forecasting takes all characters of each single forecasting method into consideration, and combines them to form a composite, which increases forecasting accuracy. The existing researches on combination forecasting select single model randomly, neglecting the internal characters of the forecasting object. After discussing the function of cointegration test and encompassing test in the selection of single model, supplemented by empirical analysis, the paper gives the single model selection guidance: no more than five suitable single models can be selected from many alternative single models for a certain forecasting target, which increases accuracy and stability.

Jiang, Chuanjin; Zhang, Jing; Song, Fugen

2014-01-01

149

Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program  

SciTech Connect

Environmental and health impacts are presented for activities associated with transient testing of nuclear fuel and material using two candidate test reactors. Transient testing involves irradiation of nuclear fuel or materials for short time-periods under high neutron flux rates. The transient testing process includes transportation of nuclear fuel or materials inside a robust shipping cask to a hot cell, removal from the shipping cask, pre-irradiation examination of the nuclear materials, assembly of an experiment assembly, transportation of the experiment assembly to the test reactor, irradiation in the test reactor, transport back to the hot cell, and post-irradiation examination of the nuclear fuel or material. The potential for environmental or health consequences during the transportation, examination, and irradiation actions are assessed for normal operations, off-normal (accident) scenarios, and transportation. Impacts to the environment (air, soil, and groundwater), are assessed during each phase of the transient testing process. This report documents the evaluation of potential consequences to the general public. This document supports the Environmental Assessment (EA) required by the U.S. National Environmental Policy Act (NEPA) (42 USC Subsection 4321 et seq.).

Annette L. Schafer; Lloyd C. Brown; David C. Carathers; Boyd D. Christensen; James J. Dahl; Mark L. Miller; Cathy Ottinger Farnum; Steven Peterson; A. Jeffrey Sondrup; Peter V. Subaiya; Daniel M. Wachs; Ruth F. Weiner

2013-11-01

150

Numerical Simulation of Transient flow through Single Blade Centrifugal Pump Impellers with Tipgap Leakage  

Microsoft Academic Search

This paper is concerned with the application of Computational Fluid Dynamics (CFD) to a low specific speed (Ns=60) single blade impeller. Single blade centrifugal pump impellers are the extreme example of impeller design, with gross deviation from conventional design practice. A time accurate three- dimensional viscous flow simulation is performed, using the multiple frames of reference sliding mesh technique, at

BRIAN DE SOUZA; JOHN DALY; ANDREW NIVEN; PATRICK FRAWLEY

2006-01-01

151

Transient response of single-domain Y-Ba-Cu-O rings to pulsed magnetic fields  

Microsoft Academic Search

Shielding current limits and magnetic diffusion characteristics have been measured at 77 K for a set of YBCO single-domain rings. These were fabricated from melt-textured cylindrical YBCO monoliths that were densified to nearly 100%, and then oriented from a single seed. The rings were surrounded by a drive coil that can, under pulse conditions, achieve applied magnetic fields in excess

T. R. Askew; J. M. Weber; Y. S. Cha; H. Claus; B. W. Veal

2003-01-01

152

[Ca2+]i transients and [Ca2+]i-dependent chloride current in single Purkinje cells from rabbit heart.  

PubMed Central

1. Single Purkinje cells, enzymatically isolated from rabbit ventricle, were studied under whole-cell voltage clamp and internally perfused with the fluorescent Ca2+ indicator, indo-1 (100 microM). 2. Fast [Ca2+]i transients were elicited by brief depolarizations from a holding voltage of -45 mV and by repolarization from very positive potentials. The peak [Ca2+]i-voltage relation was bell-shaped with a peak around +10 mV. 3. [Ca2+]i transients were completely blocked by the Ca2+ channel antagonist, nisoldipine (10 microM) and were very small when Ca2+ release from the sarcoplasmic reticulum (SR) was prevented by superfusion of cells by caffeine (1 mM) or ryanodine (10 microM). A fast application of caffeine induced a transient increase in [Ca2+]i. These results suggest [Ca2+]i transients are due to Ca(2+)-induced Ca2+ release from the SR. 4. Rate of decline of the [Ca2+]i transient was voltage dependent, suggesting contribution of the Na(+)-Ca2+ exchanger to Ca2+ efflux. At very positive potentials (> +60 mV), Ca2+ influx through the Na(+)-Ca2+ exchanger could be observed. 5. A transient outward current was observed at potentials positive to +10 mV, but only if depolarizing pulses were accompanied by a [Ca2+]i transient. 6. When the amplitude of the [Ca2+]i transient was changed by (1) changes in [Ca2+]o, (2) changes in frequency of depolarization or (3) conditioning prepulses, the amplitude of the outward current changed in the same direction. This suggests activation of the current is dependent on and graded by [Ca2+]i. 7. The outward current was observed in K(+)-free solutions, in the presence of Cs+ and TEA+, and was not blocked by 4-aminopyridine (10 mM). In contrast, DIDS (100 microM) decreased the outward current by 70 +/- 20% (mean +/- S.D., n = 9), without affecting [Ca2+]i. 8. When external Cl- was lowered, the amplitude of the outward current decreased; when internal Cl- was replaced by aspartate, it became apparent at more negative potentials. These interventions strongly suggest the current was carried by Cl-; it can therefore be referred to as a [Ca2+]i-activated Cl- current or ICl(Ca). 9. When ICl(Ca) was maximally activated during a conditioning step, steps to negative potentials revealed inward currents through ICl(Ca) (in symmetrical Cl- solutions). The fully activated I-V relation was linear. 10. ICl(Ca) could be activated at membrane potentials between -80 and +80 mV by a fast application of caffeine (10 mM), inducing Ca2+ release from the SR, demonstrating that ICl(Ca) does not require membrane depolarization or Ca2+ influx through the Ca2+ channel for its activation.(ABSTRACT TRUNCATED AT 400 WORDS)

Sipido, K R; Callewaert, G; Carmeliet, E

1993-01-01

153

Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing  

NASA Technical Reports Server (NTRS)

The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes.

Nichols, Donald K.; Huebner, Mark A.; Price, William E.; Smith, L. S.; Coss, James R.

1988-01-01

154

Information-gap robustness for the test analysis correlation of nonlinear transient simulation  

SciTech Connect

An alternative to the theory of probability is applied to the problem of assessing the robustness of test-analysis correlation to parametric sources of uncertainty. The analysis technique is based on the theory of information-gap, which models the clustering of uncertain events in families of nested sets instead of assuming a probability structure. The system investigated is the propagation of a transient impact through a layer of hyper-elastic material. The two sources of non-linearity are the softening of the constitutive law implemented to model the hyper-elastic material and contact dynamics at the interface between metallic and crushable materials. The robustness of test-analysis correlation to sources of parametric variability is first studied to identify the parameters of the model that significantly influence the agreement between measurements and predictions. Calibration under non-probabilistic uncertainty is then illustrated. Finally, two information-gap models of uncertainty are embedded to represent uncertainty not only in the knowledge of the model's parameters but also in the form of the model itself. Although computationally expensive, it is demonstrated that the information-gap reasoning can greatly enhance our understanding of a moderately complex system when the theory of probability cannot be applied due to insufficient information.

Hemez, F. M. (François M.); Ben-Haim, Yakov,; Cogan, S. (Scott)

2002-01-01

155

Selective isolation of transiently transfected cells from a mammalian cell population with vectors expressing a membrane anchored single-chain antibody  

Microsoft Academic Search

We present here a novel technology for the rapid selection of transiently transfected cells from total populations in culture. This system utilizes recombinant antibody technology to produce a ‘molecular hook’ by displaying a hapten-binding single-chain antibody (sFv) on the surface of transfected cells. Mammalian cell lines from several origins were transiently transfected with a plasmid (pHook-1) that encodes an sFv

Jonathan D. Chesnut; Apollo R. Baytan; Marijane Russell; Mei-Ping Chang; Amy Bernard; Ian H. Maxwell; James P. Hoeffler

1996-01-01

156

Transient expression of a tumor-specific single-chain fragment and a chimeric antibody in tobacco leaves  

PubMed Central

To evaluate the expression of different forms of a tumor-specific antibody in plants, we adapted a recently described Agrobacterium-mediated transient expression system. A recombinant single-chain Fv antibody (scFvT84.66) and a full-size mouse/human chimeric antibody (cT84.66) derived from the parental murine mAb T84.66 specific for the human carcinoembryonic antigen were engineered into a plant expression vector. Chimeric T84.66 heavy and light chain genes were constructed by exchanging the mouse light and heavy chain constant domain sequences with their human counterparts and cloned into two independent plant expression vectors. In vivo assembly of full-size cT84.66 was achieved by simultaneous expression of the light and heavy chains after vacuum infiltration of tobacco leaves with two populations of recombinant Agrobacterium. Upscaling the transient system permitted purification of functional recombinant antibodies from tobacco leaf extracts within a week. His6-tagged scFvT84.66 was purified by immobilized metal affinity chromatography and cT84.66 by protein A affinity chromatography. Sufficient amounts of recombinant antibodies were recovered for detailed characterization by SDS/PAGE, Western blotting, and ELISA.

Vaquero, Carmen; Sack, Markus; Chandler, John; Drossard, Jurgen; Schuster, Flora; Monecke, Michael; Schillberg, Stefan; Fischer, Rainer

1999-01-01

157

Transient expression of a tumor-specific single-chain fragment and a chimeric antibody in tobacco leaves.  

PubMed

To evaluate the expression of different forms of a tumor-specific antibody in plants, we adapted a recently described Agrobacterium-mediated transient expression system. A recombinant single-chain Fv antibody (scFvT84.66) and a full-size mouse/human chimeric antibody (cT84.66) derived from the parental murine mAb T84. 66 specific for the human carcinoembryonic antigen were engineered into a plant expression vector. Chimeric T84.66 heavy and light chain genes were constructed by exchanging the mouse light and heavy chain constant domain sequences with their human counterparts and cloned into two independent plant expression vectors. In vivo assembly of full-size cT84.66 was achieved by simultaneous expression of the light and heavy chains after vacuum infiltration of tobacco leaves with two populations of recombinant Agrobacterium. Upscaling the transient system permitted purification of functional recombinant antibodies from tobacco leaf extracts within a week. His6-tagged scFvT84.66 was purified by immobilized metal affinity chromatography and cT84.66 by protein A affinity chromatography. Sufficient amounts of recombinant antibodies were recovered for detailed characterization by SDS/PAGE, Western blotting, and ELISA. PMID:10500141

Vaquero, C; Sack, M; Chandler, J; Drossard, J; Schuster, F; Monecke, M; Schillberg, S; Fischer, R

1999-09-28

158

Effects of imipramine on the transient outward current in rabbit atrial single cells.  

PubMed Central

1. The effects of imipramine on action potential characteristics and transient outward potassium current (It) of rabbit isolated atrial myocytes were studied using the whole-cell configuration of the patch-clamp technique. 2. Imipramine, 3 microM, decreased action potential amplitude and lengthened the action potential duration measured at 50% of repolarization, whereas it did not modify the final phase of repolarization or the resting membrane potential. These results are similar to those reported in multicellular rabbit atrial preparations. 3. Imipramine, 0.1-100 microM, induced a concentration-dependent inhibition of the peak amplitude of It, a shortening of the time to peak current and an increase in the inactivation rate. The acceleration of the current inactivation is to a major extent responsible for the decrease in the integral of the outward current measured at 50 ms after the start of the pulse. 4. The drug-induced block of It was not associated with changes in the voltage-dependence of the steady-state inactivation curve or in the process of recovery from inactivation of the current. Extrapolation to zero block shows that imipramine did not block It before its activation at the onset of the depolarization. These results suggested that imipramine does not affect the inactivated or the resting state of It channels. 5. It is concluded that in rabbit isolated atrial cells, imipramine inhibits It and that this effect is responsible for the lengthening of the action potential duration produced by this drug.

Delpon, E.; Tamargo, J.; Sanchez-Chapula, J.

1992-01-01

159

Implementation and testing of the first prompt search for electromagnetic counterparts to gravitational wave transients  

Microsoft Academic Search

Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify

B. P. Abbott; R. Abbott; T. D. Abbott; M. Abernathy; T. Accadia; F. Acernese; C. Adams; R. Adhikari; C. Affeldt; P. Ajith; B. Allen; G. S. Allen; E. Amador Ceron; D. Amariutei; R. S. Amin; S. B. Anderson; W. G. Anderson; K. Arai; M. A. Arain; M. C. Araya; S. M. Aston; P. Astone; D. Atkinson; P. Aufmuth; C. Aulbert; B. E. Aylott; S. Babak; P. Baker; G. Ballardin; S. Ballmer; D. Barker; F. Barone; B. Barr; P. Barriga; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; M. Bastarrika; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. G. Beker; A. S. Bell; A. Belletoile; I. Belopolski; M. Benacquista; J. M. Berliner; A. Bertolini; J. Betzwieser; N. Beveridge; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; R. Biswas; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; B. Bland; M. Blom; O. Bock; T. P. Bodiya; C. Bogan; R. Bondarescu; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; B. Bouhou; S. Braccini; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; A. Brummit; T. Bulik; H. J. Bulten; A. Buonanno; J. Burguet--Castell; O. Burmeister; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Cain; E. Calloni; J. B. Camp; P. Campsie; J. Cannizzo; K. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; O. Chaibi; T. Chalermsongsak; E. Chalkley; P. Charlton; E. Chassande-Mottin; S. Chelkowski; Y. Chen; A. Chincarini; A. Chiummo; H. Cho; N. Christensen; S. S. Y. Chua; C. T. Y. Chung; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. Clark; J. H. Clayton; F. Cleva; E. Coccia; P.-F. Cohadon; C. N. Colacino; J. Colas; A. Colla; M. Colombini; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. Coughlin; J.-P. Coulon; P. Couvares; D. M. Coward; D. C. Coyne; J. D. E. Creighton; T. D. Creighton; A. M. Cruise; A. Cumming; L. Cunningham; E. Cuoco; R. M. Cutler; K. Dahl; S. L. Danilishin; R. Dannenberg; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; D. DeBra; G. Debreczeni; J. Degallaix; W. Del Pozzo; M. del Prete; T. Dent; V. Dergachev; R. DeRosa; R. DeSalvo; V. Dhillon; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; M. Di Paolo Emilio; A. Di Virgilio; M. Díaz; A. Dietz; F. Donovan; K. L. Dooley; S. Dorsher; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J.-C. Dumas; S. Dwyer; T. Eberle; M. Edgar; M. Edwards; A. Effler; P. Ehrens; G. Endroczi; R. Engel; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Y. Fan; B. F. Farr; W. Farr; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; M. Flanigan; S. Foley; E. Forsi; L. A. Forte; N. Fotopoulos; J.-D. Fournier; J. Franc; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; J. K. Fridriksson; D. Friedrich; P. Fritschel; V. V. Frolov; P. J. Fulda; M. Fyffe; M. Galimberti; L. Gammaitoni; M. R. Ganija; J. Garcia; J. A. Garofoli; F. Garufi; M. E. Gáspár; G. Gemme; R. Geng; E. Genin; A. Gennai; L. Á. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; C. Gill; E. Goetz; L. M. Goggin; G. González; M. L. Gorodetsky; S. Goßler; R. Gouaty; C. Graef; M. Granata; A. Grant; S. Gras; C. Gray; N. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Greverie; R. Grosso; H. Grote; S. Grunewald; G. M. Guidi; C. Guido; R. Gupta; E. K. Gustafson; R. Gustafson; T. Ha; B. Hage; J. M. Hallam; D. Hammer; G. Hammond; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J.-F. Hayau; T. Hayler; J. Heefner; A. Heidmann; M. C. Heintze; H. Heitmann; P. Hello; M. A. Hendry; I. S. Heng; A. W. Heptonstall; V. Herrera; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; J. Homan; T. Hong; S. Hooper; D. J. Hosken; J. Hough; E. J. Howell; B. Hughey; S. Husa; S. H. Huttner; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; K. Izumi; M. Jacobson; H. Jang; P. Jaranowski; W. W. Johnson; D. I. Jones; G. Jones; R. Jones; L. Ju; P. Kalmus; V. Kalogera; I. Kamaretsos; S. Kandhasamy; G. Kang; J. B. Kanner; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; S. Kawamura; F. Kawazoe; W. Kells; D. G. Keppel; Z. Keresztes; A. Khalaidovski; F. Y. Khalili; E. A. Khazanov; B. Kim; C. Kim; D. Kim; H. Kim; K. Kim; N. Kim; Y.-M. Kim; P. J. King; M. Kinsey; D. L. Kinzel; J. S. Kissel; S. Klimenko; K. Kokeyama; V. Kondrashov; R. Kopparapu; S. Koranda; W. Z. Korth; I. Kowalska; D. Kozak; V. Kringel; S. Krishnamurthy

2011-01-01

160

COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems  

SciTech Connect

The COMMIX-LAR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-lA to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a keg model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The internal aspects of the COMMIX-LAR/P program are presented, covering descriptions of subprograms, variables, and files.

Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

1992-09-01

161

COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems  

SciTech Connect

The COMMIX-1AR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-1A to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a k-[var epsilon] model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The input preparation and execution procedures are presented for the COMMIX-1AR/P program and several postprocessor programs which produce graphical displays of the calculated results.

Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

1992-09-01

162

Impact of transient single-phase heat transfer modeling on predicted BWR fuel stability margins  

Microsoft Academic Search

Boiling flow instabilities must be considered in the design and analysis of many devices in energy production, e.g., boiling water nuclear reactors (BWRs). The most common thermal-hydraulic instability mechanism of interest to BWR operation in known as density-wave oscillations. An important aspect of analytically investigating density-wave oscillations deals with heater wall dynamic modeling in the single- and two-phase regions, respectively.

R. P. Taleyarkhan; A. F. McFarlane; M. Z. Podowski; R. T. Jr. Lahey

1987-01-01

163

Automatisation of the single-breath nitrogen washout test  

Microsoft Academic Search

The paper presents a computer-based system for performance and analysis of the single-breath nitrogen washout test (Sb-N2 test). A pneumotachometer and a rapid gas analyser are used for volume flow rate and nitrogen fraction measurements. The\\u000a data are acquired and analysed by a PDP-11\\/34 computer. Several sources of measurement errors are considered. An algorithm\\u000a is proposed to reduce errors in

M. F. V. Melo; A. Giannella Neto

1989-01-01

164

Chilldown study of the single stage inducer test rig  

NASA Technical Reports Server (NTRS)

Of the six chilldown tests, data from only one could be used for evaluation. During the rest of the chilldown tests, there was leakage hydrogen flow into the pump cavity prior to the initiation of the chilldown test. In all of the tests the hydrogen condition into the pump was probably 100% vapor. The data from this one test, therefore, can be used to compare only the single phase fluid correlation in the analytical pump chilldown model. In general, the actual pump chilled down much faster than predicted by the analytical pump model. There were insufficient data from the test to measure the pump flow rate and pump inlet fluid condition; therefore, these parameters were extrapolated based on related data which were available. However, even with the highest probable flow rate, the pump chilled faster than predicted.

Kimura, L. A.

1972-01-01

165

Transient and steady-state tests of the space power research engine with resistive and motor loads  

NASA Technical Reports Server (NTRS)

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

166

Modal Analysis of a Typical Fighter Aircraft Using Transient Testing Technique.  

National Technical Information Service (NTIS)

The dynamic performance of individual structural components and the whole aircraft was evaluated. The dynamic properties of the aircraft and its components were analyzed. One hundred and thirty nine locations for transient imputs are chosen using an instr...

R. Balasubramaniam D. S. Ramakrishna P. S. Vijayakumar

1985-01-01

167

A one-dimensional transient model of a single-stage, downward-firing entrained-flow gasifier  

SciTech Connect

The integrated gasification combined cycle (IGCC) technology has emerged as an attractive alternative to conventional coal-fired power plant technology due to its higher efficiency and cleaner environmental performance especially with the option of CO{sub 2} capture and sequestration. The core unit of this technology is the gasifier whose optimal performance must be understood for efficient operation of IGCC power plants. This need has led a number of researchers to develop gasifier models of varying complexities. Whereas high-fidelity CFD models can accurately predict most key aspects of gasifier performance, they are computationally expensive and typically take hours to days to execute on high-performance computers. Therefore, faster one-dimensional (1D) partial differential equation (PDE)-based models are required for use in dynamic simulation studies, control system analysis, and training applications. A number of 1D gasifier models can be found in the literature, but most are steady-state and have limited application in the practical operation of the gasifier. As a result, 1D PDE-based dynamic models are needed to further study and predict gasifier performance under a wide variety of process conditions and disturbances. In the present study, a 1D transient model of a single-stage downward flow GE/Texaco-type gasifier has been developed. The model comprises mass, momentum and energy balances for the gas and solid phases. The model considers the initial gasification processes of water evaporation and coal devolatilization. In addition, the key heterogeneous and homogeneous chemical reactions have been modeled. The resulting time-dependent PDE model is solved using the well-known method of lines approach in Aspen Custom Modeler®, whereby the PDEs are discretized in the spatial domain and the resulting differential algebraic equations (DAEs) are then solved to obtain the transient response. The transient response of various gasifier performance parameters to certain disturbances commonly encountered in the real world operation of commercial IGCC plants will be presented. These disturbances include ramp and step changes in input variables such as coal flow rate, oxygen-to-coal ratio and water-to-coal ratio, among others. Comparison of gasifier model predictions to available dynamic data will also be discussed.

Kasule, J.; Turton, R.; Bhattacharyya, D.; Zitney, S.

2012-01-01

168

Boiling Water Reactor Loss of Coolant Tests Single Failure Tests with ROSA-III  

Microsoft Academic Search

The single failure tests with the ROSA-III were simulated BWR LOCA experiments by the scaled BWR test facility resulting from a 200% double-ended break at the recirculation pump suction line to evaluate the core cooling capability of a BWR ECCS under the single failure condition.The experimental results showed that the loss of LPCS and one LPCI resulted in the highest

Kunihisa SODA; Kanji TASAKA; Nobuaki ABE; Masayoshi SHIBA

1983-01-01

169

Statistical properties of single-marker tests for rare variants.  

PubMed

With the dramatic technological developments of genome-wide association single-nucleotide polymorphism (SNP) chips and next generation sequencing, human geneticists now have the ability to assay genetic variation at ever-rarer allele frequencies. To fully understand the impact of these rare variants on common, complex diseases, we must be able to accurately assess their statistical significance. However, it is well established that classical association tests are not appropriate for the analysis of low-frequency variation, giving spurious findings when observed counts are too few. To further our understanding of the asymptotic properties of traditional association tests, we conducted a range of simulations of a typical rare variant (~1%) under the null hypothesis and tested the allelic ?2, Cochran-Armitage trend, Wald, and Fisher's exact tests. We demonstrate that rare variation shows marked deviation from the expected distributional behavior for each test, with fewer minor alleles corresponding to a greater degree of test statistics deflation. The effect becomes more pronounced at progressively smaller ? levels. We also show that the Wald test is particularly deflated at ? levels consistent with genome-wide association significance, much more so than the other association tests considered. In general, these classical association tests are inappropriate for the analysis of variants for which the minor allele is observed fewer than 80 times, largely irrespective of sample size. PMID:24739319

Bigdeli, T Bernard; Neale, Benjamin M; Neale, Michael C

2014-06-01

170

Type-curve analyses of single- and cross-hole pneumatic tests in unsaturated fractured tuffs  

NASA Astrophysics Data System (ADS)

We describe selected pressure and pressure derivative type-curve analyses of single and cross-hole pneumatic injection tests recently completed in unsaturated fractured tuffs at the Apache Leap Research Site (ALRS) near Superior, Arizona. Type curve analyses of transient data from single-hole tests yield information about air permeability, skin factor, borehole storage, phenomenology and dimensionality of the flow regime on a nominal scale of 1 m in the vicinity of each test interval. We find that transient air permeabilities agree well with steady state values but correlate poorly with fracture density. Larger scale cross-hole pneumatic tests were conducted by injecting air into a relatively short borehole interval of length 1-2 m, while monitoring air pressure and temperature in the injection interval; barometric pressure, air temperature and relative humidity at the surface; as well as air pressure and temperature in 13 short (0.5-2 m) and 24 longer (4-20 m) intervals within the injection and surrounding boreholes. We discuss one of these tests labeled PP4. Analyses of pressure data from individual monitoring intervals yield information about pneumatic connections between the injection and monitoring intervals, corresponding directional air permeabilities, and air-filled porosities. All of these quantities vary considerably from one monitoring interval to another on scales ranging from a few meters to well over 20 meters. Together with the results of earlier site investigations our single and cross-hole test analyses reveal that, at the ALRS, a) the pneumatic pressure behavior of fractured tuff is amenable to analysis by methods that treat the rock as a continuum on scales ranging from meters to tens of meters; b) this continuum is representative primarily of interconnected fractures; c) its pneumatic properties vary strongly with location, direction and scale; in particular, the mean of pneumatic permeabilities increases, and their variance decreases, with scale; and d) this scale effect is most probably due to the presence in the rock of various size fractures that are interconnected on a variety of scales.

Illman, Walter A.; Thompson, Dick L.; Neuman, Shlomo P.

171

Transient potentiation of spontaneous EPSPs in rat mossy cells induced by depolarization of a single neurone.  

PubMed Central

1. The amplitude and frequency of spontaneously occurring EPSPs recorded intracellularly in rat mossy cells was estimated by measuring membrane potential variance in short segments of a continuous voltage record. Changes in variance reflected changes in the amplitude and/or the frequency of spontaneous EPSPs. 2. Short trains of depolarizing current pulses evoked a delayed increase in membrane potential variance in 55% of trials. Variance increased by 487% during these responses and remained elevated for 124 +/- 16 s. Increases in variance were not associated with large changes in the intrinsic properties of the mossy cell such as resting membrane potential and input resistance. We termed this phenomenon depolarization-related potentiation (DRP). 3. Epochs of elevated variance were associated with an increase in both the average amplitude and frequency of spontaneous EPSPs. During the peak of the response, the mean interval between spontaneous EPSPs decreased by 36.8%. Computer-generated voltage records with randomly distributed EPSP amplitudes and inter-EPSP intervals suggested that this decrease in inter-EPSP intervals was not sufficient to account for the magnitude of the variance increase observed. Based on this model, we estimated that a 90% increase in the average amplitude of spontaneous EPSPs, in addition to the experimentally measured decrease in the average inter-EPSP interval, was required to reproduce the magnitude of the change in variance observed. In the potentiated state, the amplitude of spontaneous EPSPs often exceeded 10 mV. 4. We also observed epochs of increased variance that occurred spontaneously. These spontaneous epochs closely resembled epochs evoked by depolarizing stimuli, suggesting that the stimulus was acting as a trigger for a spontaneously occurring behaviour. Additional evidence supporting this hypothesis was provided by the observation that stereotyped patterns of increased variance could be evoked by brief stimuli, such as a single 5 s depolarizing step. Dual intracellular recordings from two mossy cells demonstrated that spontaneous epochs of increased variance occurred independently in different neurones. This result makes it unlikely that these variance increases were due to a global change in the slice environment such as a propagating wave of potassium ions. 5. Bath application of the Na+ channel blocker TTX eliminated most, but not all, of the normal on-going spontaneous EPSPs in mossy cells. Treatment with depolarizing current pulses was effective in potentiating TTX-resistant spontaneous EPSPs in three of seven trials. Potentiation also decreased the mean interval between TTX-resistant miniature EPSPs (by an average of 66.9%) in two trials examined. 6. These results suggest that DRP results from the activation of an intrinsic phenomenon within the dentate gyrus by strong depolarization of a single mossy cell. Our data suggest that several mechanisms are involved in the expression of DRP since changes in EPSP amplitude and frequency can occur with varying delays from the stimulus. The ability of depolarizing current pulses to potentiate TTX-resistant miniature EPSPs suggests that at least one component of this plasticity occurs at the granule cell-mossy cell synapse.

Strowbridge, B W; Schwartzkroin, P A

1996-01-01

172

System level latchup mitigation for single event and transient radiation effects on electronics  

DOEpatents

A ``blink`` technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements. 18 figs.

Kimbrough, J.R.; Colella, N.J.

1997-09-30

173

System level latchup mitigation for single event and transient radiation effects on electronics  

DOEpatents

A "blink" technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements.

Kimbrough, Joseph Robert (Pleasanton, CA) [Pleasanton, CA; Colella, Nicholas John (Livermore, CA) [Livermore, CA

1997-01-01

174

FOREVER ALONE? TESTING SINGLE ECCENTRIC PLANETARY SYSTEMS FOR MULTIPLE COMPANIONS  

SciTech Connect

Determining the orbital eccentricity of an extrasolar planet is critically important for understanding the system's dynamical environment and history. However, eccentricity is often poorly determined or entirely mischaracterized due to poor observational sampling, low signal-to-noise, and/or degeneracies with other planetary signals. Some systems previously thought to contain a single, moderate-eccentricity planet have been shown, after further monitoring, to host two planets on nearly circular orbits. We investigate published apparent single-planet systems to see if the available data can be better fit by two lower-eccentricity planets. We identify nine promising candidate systems and perform detailed dynamical tests to confirm the stability of the potential new multiple-planet systems. Finally, we compare the expected orbits of the single- and double-planet scenarios to better inform future observations of these interesting systems.

Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.; Bailey, J.; Salter, G. S.; Wright, D. [Department of Astrophysics, School of Physics, Faculty of Science, The University of New South Wales, Sydney, NSW 2052 (Australia); Wang Songhu; Zhou Jilin [Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210093 (China); Butler, R. P. [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States); Jones, H. R. A. [University of Hertfordshire, Centre for Astrophysics Research, Science and Technology Research Institute, College Lane, AL10 9AB Hatfield (United Kingdom); O'Toole, S. J. [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Carter, B. D., E-mail: rob@phys.unsw.edu.au [Faculty of Sciences, University of Southern Queensland, Toowoomba, Queensland 4350 (Australia)

2013-09-15

175

Single particle friction tests with cellulose acetate sphere samples  

SciTech Connect

This reporter represents a detailed account of all the experimental work carried out for LLNL using the ''single particle shear cell'' in the department of Chemical Process Engineering of Surrey University, Guildford, United Kingdom. Experimental work with two spheres in contact was performed. Particles were positioned into the specially made sample holders by the micro screws. The contact centres were lined up under the magnifying glass. The behavior of the interparticle contact region between the two spheres was examined by performing the following series of tests: (i) normal force versus normal displacement test, (ii) tangential force limit at gross sliding with increased normal load and decreasing normal load, (iii) tangential force versus micro displacement during initial loading to friction limit and during unloading from friction limit. Work was also performed on single sphere against a flat wall surface. Results are discussed. 34 figs.

Tuezen, U.

1989-05-31

176

Loss-of-flow transient reactor test facility tests l6 and l7 with irradiated liquid-metal fast breeder reactor type fuel  

Microsoft Academic Search

This paper describes Transient Reactor Test Facility tests L6 and L7, in which a loss-of-flow accident sequence was simulated using three fuel elements containing (Pu,U)Oâ. Fuel dispersal rates at 10 and 20 times nominal power were measured using the 1.2-m fast neutron hodoscope. The measured axial fuel density variations were weighted with typical liquid-metal fast breeder reactor fuel-worth distributions so

R. Simms; G. E. Marsh; A. B. Rothman; G. S. Stanford

1981-01-01

177

TRAVELLING WAVE AND STANDING WAVE SINGLE CELL HIGH GRADIENT TESTS  

SciTech Connect

Accelerating gradient is one of the crucial parameters affecting design, construction and cost of next-generation linear accelerators. Operating accelerating gradient in normal conducting accelerating structures is limited by rf breakdown. In this paper we describe an experimental setup for study of these limits for 11.4 GHz travelingwave and standing-wave accelerating structures. The setup uses matched mode converters that launch the circular TM01 mode into short test structures. The test structures are designed so that the electromagnetic fields in one cell mimic the fields in prototype structures for the Next Linear Collider. Fields elsewhere in the test structures and in the mode converters are significantly lower than in this single cell. This setup allows economic testing of different cell geometries, cell materials and preparation techniques with short turn around time. Here we present design considerations and describe planned experiments.

Dolgashev, V

2004-08-24

178

Single-qubit tests of Bell-like inequalities  

SciTech Connect

This paper discusses some tests of Bell-like inequalities not requiring entangled states. The proposed tests are based on consecutive measurements on a single qubit. Available hidden-variable models for a single qubit [see, e.g., J. S. Bell, Rev. Mod. Phys. 38, 447 (1966)] reproduce the predictions of quantum mechanics and hence violate the Bell-like inequalities addressed in this paper. It is shown how this fact is connected with the state 'collapse' and with its random nature. Thus, it becomes possible to test truly realistic and deterministic hidden-variable models. In this way, it can be shown that a hidden-variable model should entail at least one of the following features: (i) nonlocality, (ii) contextuality, or (iii) discontinuous measurement-dependent probability functions. The last two features are put to the test with the experiments proposed in this paper. A hidden-variable model that is noncontextual and deterministic would be at variance with some predictions of quantum mechanics. Furthermore, the proposed tests are more likely to be loophole-free, as compared to former ones.

Zela, F. de [Departamento de Ciencias, Seccion Fisica Pontificia, Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2007-10-15

179

Evaluation of the Non-Transient Hydrologic Source Term from the CAMBRIC Underground Nuclear Test in Frenchman Flat, Nevada Test Site  

SciTech Connect

Hydrologic Source Term (HST) calculations completed in 1998 at the CAMBRIC underground nuclear test site were LLNL's first attempt to simulate a hydrologic source term at the NTS by linking groundwater flow and transport modeling with geochemical modeling (Tompson et al., 1999). Significant effort was applied to develop a framework that modeled in detail the flow regime and captured all appropriate chemical processes that occurred over time. However, portions of the calculations were simplified because of data limitations and a perceived need for generalization of the results. For example: (1) Transient effects arising from a 16 years of pumping at the site for a radionuclide migration study were not incorporated. (2) Radionuclide fluxes across the water table, as derived from infiltration from a ditch to which pumping effluent was discharged, were not addressed. (3) Hydrothermal effects arising from residual heat of the test were not considered. (4) Background data on the ambient groundwater flow direction were uncertain and not represented. (5) Unclassified information on the Radiologic Source Term (RST) inventory, as tabulated recently by Bowen et al. (2001), was unavailable; instead, only a limited set of derived data were available (see Tompson et al., 1999). (6) Only a small number of radionuclides and geochemical reactions were incorporated in the work. (7) Data and interpretation of the RNM-2S multiple well aquifer test (MWAT) were not available. As a result, the current Transient CAMBRIC Hydrologic Source Term project was initiated as part of a broader Phase 2 Frenchman Flat CAU flow and transport modeling effort. The source term will be calculated under two scenarios: (1) A more specific representation of the transient flow and radionuclide release behavior at the site, reflecting the influence of the background hydraulic gradient, residual test heat, pumping experiment, and ditch recharge, and taking into account improved data sources and modeling approaches acquired or developed since the previous work (as in Pawloski et al., 2001, at the CHESHIRE site). This will be referred to as the transient CAMBRIC source term. (2) A generic release model made under steady-state flow conditions, in the absence of any transient effect, at the same site with the same RST for use in the development of simple release models at the other nine underground test sites in the Frenchman Flat CAU. This will be referred to as the steady state (non-transient) source term. The purpose of this report is to summarize the results of our steady state source term simulations. Additional details pertaining to these results, the transient model results, and the overall strategy, rationale, and assumptions used in the models will be documented in a separate report.

Tompson, A B; Maxwell, R M; Carle, S F; Zavarin, M; Pawloski, G A; Shumaker, D E

2005-08-05

180

GPI-anchored single chain Fv - an effective way to capture transiently-exposed neutralization epitopes on HIV-1 envelope spike  

PubMed Central

Background Identification of broad neutralization epitopes in HIV-1 envelope spikes is paramount for HIV-1 vaccine development. A few broad neutralization epitopes identified so far are present on the surface of native HIV-1 envelope spikes whose recognition by antibodies does not depend on conformational changes of the envelope spikes. However, HIV-1 envelope spikes also contain transiently-exposed neutralization epitopes, which are more difficult to identify. Results In this study, we constructed single chain Fvs (scFvs) derived from seven human monoclonal antibodies and genetically linked them with or without a glycosyl-phosphatidylinositol (GPI) attachment signal. We show that with a GPI attachment signal the scFvs are targeted to lipid rafts of plasma membranes. In addition, we demonstrate that four of the GPI-anchored scFvs, but not their secreted counterparts, neutralize HIV-1 with various degrees of breadth and potency. Among them, GPI-anchored scFv (X5) exhibits extremely potent and broad neutralization activity against multiple clades of HIV-1 strains tested. Moreover, we show that GPI-anchored scFv (4E10) also exhibited more potent neutralization activity than its secretory counterpart. Finally, we demonstrate that expression of GPI-anchored scFv (X5) in the lipid raft of plasma membrane of human CD4+ T cells confers long-term resistance to HIV-1 infection, HIV-1 envelope-mediated cell-cell fusion, and the infection of HIV-1 captured and transferred by human DCs. Conclusions Thus GPI-anchored scFv could be used as a general and effective way to identify antibodies that react with transiently-exposed neutralization epitopes in envelope proteins of HIV-1 and other enveloped viruses. The GPI-anchored scFv (X5), because of its breadth and potency, should have a great potential to be developed into anti-viral agent for HIV-1 prevention and therapy.

2010-01-01

181

Instrumented Taylor anvil-on-rod impact tests for validating applicability of standard strength models to transient deformation states  

NASA Astrophysics Data System (ADS)

Instrumented Taylor anvil-on-rod impact tests have been conducted on oxygen-free electronic copper to validate the accuracy of current strength models for predicting transient states during dynamic deformation events. The experiments coupled the use of high-speed digital photography to record the transient deformation states and laser interferometry to monitor the sample back (free surface) velocity as a measure of the elastic/plastic wave propagation through the sample length. Numerical continuum dynamics simulations of the impact and plastic wave propagation employing the Johnson-Cook [Proceedings of the Seventh International Symposium on Ballistics, 1983, The Netherlands (Am. Def. Prep. Assoc. (ADPA)), pp. 541-547], Zerilli-Armstrong [J. Appl. Phys. C1, 1816 (1987)], and Steinberg-Guinan [J. Appl. Phys. 51, 1498 (1980)] constitutive equations were used to generate transient deformation profiles and the free surface velocity traces. While these simulations showed good correlation with the measured free surface velocity traces and the final deformed sample shape, varying degrees of deviations were observed between the photographed and calculated specimen profiles at intermediate deformation states. The results illustrate the usefulness of the instrumented Taylor anvil-on-rod impact technique for validating constitutive equations that can describe the path-dependent deformation response and can therefore predict the transient and final deformation states.

Eakins, D. E.; Thadhani, N. N.

2006-10-01

182

The dipole flow test: A new single-borehole test for aquifer characterization  

Microsoft Academic Search

A new single-borehole measurement technique for confined aquifers, the dipole flow test, yields the vertical distributions of the horizontal hydraulic conductivity, the vertical hydraulic conductivity, and the specific storativity when applied to different borehole intervals. The test utilizes straddle packers to isolate two chambers in the borehole, pressure transducers to monitor drawdown in them, and a small pump to create

Z. J. Kabala

1993-01-01

183

Intracranial blood flow measured with single photon emission computer tomography (SPECT) during transient -6 degrees head-down tilt.  

PubMed

Regional cerebral blood flow (CBF) during a transient head-down tilt of -6 degrees (-6 degrees HDT) was measured with single photon emission computer tomography (SPECT). CBF was measured and averaged for both sides of the brain areas; e.g., the bilateral anterior cerebral artery (bACA) area, the middle cerebral artery (bMCA) area, the posterior cerebral artery (bPCA) area, bilateral basal ganglia, and the cerebellum. Among these areas, a significant increase in CBF was observed in the basal ganglia and the cerebellum during -6 degrees HDT compared to pre-HDT. When CBF was measured separately in the left or right brain area, these significances disappeared, although a trend of increase or decrease was still observable. A trend of increase was observed in the left anterior cerebral artery (IACA) area, the right middle cerebral artery (rMCA) area, the right posterior cerebral artery (rPCA) area, the left and right basal ganglia, and the cerebellum. In rACA, IMCA and IPCA areas, a slight decrease in CBF was observed. At the same time, cardiac parameters were measured. Heart rate (HR), stroke volume (SV) and cardiac output (CO) did not change significantly, although SV slightly increased and HR slightly decreased during -6 degrees HDT. PMID:8161321

Satake, H; Konishi, T; Kawashima, T; Matsunami, K; Uno, T; Imai, S; Yamada, H; Hirakawa, C

1994-02-01

184

Semiscale steam line break transient test prediction with the RELAP5\\/MOD2 code  

Microsoft Academic Search

Although ruptures of steam generator main steam lines are not expected to occur often in pressurized water reactor (PWR) plants, the potential consequences of these events necessitate their examination. Steam line break transients can lead to overcooling and possibly repressurization of the primary coolant system. This phenomenon, termed pressurized thermal shock, poses a threat to the integrity of the PWR

T. H. Chen; T. J. Boucher

1985-01-01

185

Transient Submodeling Analysis for Board-Level Drop Tests of Electronic Packages  

Microsoft Academic Search

We present in this paper a submodeling analysis procedure capable of solving transient mechanical responses of board-level electronic packages subjected to drop impact loads, involving large deformations and nonlinear elastoplastic constitutive relationships for the solder alloy. This paper is focused on the verification of this submodeling analysis procedure and to investigate solution deviations caused by several abbreviated global models that

Tsung-Yueh Tsai; Chang-Lin Yeh; Yi-Shao Lai; Rong-Sheng Chen

2007-01-01

186

Novel board level drop test simulation using implicit transient analysis with input-G method  

Microsoft Academic Search

In recent several years, there are many efforts to study the reliability performance of IC package under drop impact loading by numerical modeling. Most of the models utilize LS-DYNA or ABAQUS types of explicit solvers. However, there is a lack of efficient implicit model for the organization without access to explicit solvers. This paper presents a novel non-linear transient dynamics

Jing-en Luan; Tong Yan Tee

2004-01-01

187

Outbreak of Transient Conversions of the QuantiFERON-TB Gold In-Tube Test in Laboratory Health Care Worker Screenings  

PubMed Central

Gamma interferon release assays were recently introduced in health care worker (HCWs) screenings for tuberculosis surveillance. In longitudinal surveys, conversions and reversions are seen, and yet whether these changes are unspecific or are an expression of new infections and microbial clearance remains unclear. In order to further elucidate these changes, we analyzed an outbreak of 15 transient conversions in 53 HCWs who operate in the same laboratory and handle specimens potentially containing Mycobacterium tuberculosis who underwent screening by the QuantiFERON-TB Gold In-Tube (QFT-GIT) test between 11 May and 30 June 2010: 15/46 (33%) negative HCWs showed a conversion and then reverted after 7 to 107 days. To validate these results, an evaluation of methodological procedures and test reliability, as well as an analysis of results obtained during the same period and processed by the same laboratory, was carried out. For the latter purpose, QFT-GIT results determined for 78 ward HCWs who underwent screening during the same period and were employed in departments with at least 3 infectious tuberculosis patients per year or had cared for an infectious patient without airborne precautions were analyzed with the following results: 6/63 (9%) HCWs with negative results in 3 different departments showed transient conversion (P = 0.002; odds ratio, 4.60; 95% confidence interval, 1.62 to 13.04). A retrospective survey of in-house biosafety practices led to determination of a single exposure factor within the laboratory. These data emphasize the validity of the hypothesis that a transient conversion demonstrates the presence of a real tubercular infection and could be an important indicator for occupational biosafety concerns. They also confirm that subjects with recent conversion should be retested before chest radiography and chemotherapy is offered.

Peracchi, Marta; Zorzi, Diego; Fiorio, Silvia; Fallico, Loredana; Palu, Giorgio

2012-01-01

188

A Single Well Tracer Test for Aquifer Characterization  

NASA Astrophysics Data System (ADS)

Effective and efficient contaminated site remediation requires site-specific knowledge of physical, chemical and biological properties of the aquifer (e.g., hydraulic conductivity, porosity, ion exchange capacity, redox capacity, and biodegradation potential). Aquifer property measurement techniques for groundwater transport and reactions are too costly or not-representative of in situ conditions and therefore there is an over-reliance on literature values or model assumptions. This results in overly uncertain predictions of in situ performance and therefore unnecessarily cautious risk assessment and costly remediation strategies. Therefore, cost-effective site investigative tools that have the capability of producing high quality characterization data are required. A single well tracer test called the dipole flow and reactive tracer test (DFRTT) is proposed as an alternative to current parameter estimation methods. This test circulates groundwater between isolated injection (source) and extraction (sink) chambers within a single well. Once steady-state flow has been reached, conservative and reactive tracers are added to the injected solution and the concentration of the tracers and their reaction products can be monitored in the extracted solution. These tracer breakthrough curves are analyzed by a an interpretation model to obtain parameter estimates. A dipole probe prototype has been constructed at the University of Waterloo and more than 50 field tests have been conducted in the unconfined sand aquifer at CFB Borden near Alliston, ON. Four characteristic type or response curves were observed. The DFRTT showed good repeatability between tests and captures both the response of the disturbed zone and formation. The DFRTT response profiles were determined to be scalable to some of the key system design parameters. Estimates of the hydraulic conductivity of the aquifer were within literature values, but variability at the sensing scale of the dipole tool was observed. This presentation focuses on the tracer data collected to date, model interpretation efforts, and outstanding issues that need to be addressed for this technology to be used widely.

Roos, G.; Thomson, N. R.

2009-05-01

189

Coincident steam generator tube rupture and stuck-open safety relief valve carryover tests: MB-2 steam generator transient response test program  

SciTech Connect

In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. In addition to the release of fission products from the bulk steam generator water by moisture carryover, there exists the possibility that some primary coolant may be released without having first mixed with the bulk water - a process called primary coolant bypassing. The MB-2 Phase II test program was designed specifically to identify the processes for droplet carryover during SGTR faults and to provide data of sufficient accuracy for use in developing physical models and computer codes to describe activity release. The test program consisted of sixteen separate tests designed to cover a range of steady-state and transient fault conditions. These included a full SGTR/SORV transient simulation, two SGTR overfill tests, ten steady-state SGTR tests at water levels ranging from very low levels in the bundle up to those when the dryer was flooded, and three moisture carryover tests without SGTR. In these tests the influence of break location and the effect of bypassing the dryer were also studied. In a final test the behavior with respect to aerosol particles in a dry steam generator, appropriate to a severe accident fault, was investigated.

Garbett, K.; Mendler, O.J.; Gardner, G.C.; Garnsey, R.; Young, M.Y.

1987-03-01

190

Calcium transient dynamics and the mechanisms of ventricular vulnerability to single premature electrical stimulation in Langendorff-perfused rabbit ventricles  

PubMed Central

BACKGROUND Single strong premature electrical stimulation (S2) may induce figure-eight reentry. We hypothesize that Ca current-mediated slow-response action potentials (APs) play a key role in the propagation in the central common pathway (CCP) of the reentry. METHODS We simultaneously mapped optical membrane potential (Vm) and intracellular Ca (Cai) transients in isolated Langendorff-perfused rabbit ventricles. Baseline pacing (S1) and a cathodal S2 (40 – 80 mA) were given at different epicardial sites with a coupling interval of 135 ± 20 ms. RESULTS In all 6 hearts, S2 induced graded responses around the S2 site. These graded responses propagated locally toward the S1 site and initiated fast APs from recovered tissues. The wavefront then circled around the refractory tissue near the site of S2. At the side of S2 opposite to the S1, the graded responses prolonged AP duration while the Cai continued to decline, resulting in a Cai sinkhole (an area of low Cai). The Cai in the sinkhole then spontaneously increased, followed by a slow Vm depolarization with a take-off potential of ?40 ± 3.9 mV, which was confirmed with microelectrode recordings in 3 hearts. These slow-response APs then propagated through CCP to complete a figure-eight reentry. CONCLUSION We conclude that a strong premature stimulus can induce a Cai sinkhole at the entrance of the CCP. Spontaneous Cai elevation in the Cai sinkhole precedes the Vm depolarization, leading to Ca current-mediated slow propagation in the CCP. The slow propagation allows more time for tissues at the other side of CCP to recover and be excited to complete figure-eight reentry.

Hayashi, Hideki; Kamanu, Santosh Dora; Ono, Norihiko; Kawase, Ayaka; Chou, Chung-Chuan; Weiss, James N.; Karagueuzian, Hrayr S.; Lin, Shien-Fong; Chen, Peng-Sheng

2009-01-01

191

Radiation tests of single photon avalanche diode for space applications  

NASA Astrophysics Data System (ADS)

Single photon avalanche diodes (SPADs) have been recently studied as photodetectors for applications in space missions. In this presentation we report the results of radiation hardness test on large area SPAD (actual results refer to SPADs having 500 ?m diameter). Dark counts rate as low as few kHz at -10 °C has been obtained for the 500 ?m devices, before irradiation. We performed bulk damage and total dose radiation tests with protons and gamma-rays in order to evaluate their radiation hardness properties and their suitability for application in a Low Earth Orbit (LEO) space mission. With this aim SPAD devices have been irradiated using up to 20 krad total dose with gamma-rays and 5 krad with protons. The test performed show that large area SPADs are very sensitive to proton doses as low as 2×108 (1 MeV eq) n/cm2 with a significant increase in dark counts rate (DCR) as well as in the manifestation of the "random telegraph signal" effect. Annealing studies at room temperature (RT) and at 80 °C have been carried out, showing a high decrease of DCR after 24-48 h at RT. Lower protons doses in the range 1-10×107 (1 MeV eq) n/cm2 result in a lower increase of DCR suggesting that the large-area SPADs tested in this study are well suitable for application in low-inclination LEO, particularly useful for gamma-ray astrophysics.

Moscatelli, Francesco; Marisaldi, Martino; Maccagnani, Piera; Labanti, Claudio; Fuschino, Fabio; Prest, Michela; Berra, Alessandro; Bolognini, Davide; Ghioni, Massimo; Rech, Ivan; Gulinatti, Angelo; Giudice, Andrea; Simmerle, Georg; Candelori, Andrea; Mattiazzo, Serena; Sun, Xiaoli; Cavanaugh, John F.; Rubini, Danilo

2013-05-01

192

Automatisation of the single-breath nitrogen washout test.  

PubMed

The paper presents a computer-based system for performance and analysis of the single-breath nitrogen washout test (Sb-N2 test). A pneumotachometer and a rapid gas analyser are used for volume flow rate and nitrogen fraction measurements. The data are acquired and analysed by a PDP-11/34 computer. Several sources of measurement errors are considered. An algorithm is proposed to reduce errors in flow measurements due to viscosity variation in respired air. The algorithm for closing volume (CV) detection and calculation of other Sb-N2 parameters is developed from 50 tracings of 18 subjects. The CV is obtained by an iterative linear fitting of the later half of the Sb-N2 curve. Comparisons between computer and hand measurements of three trained readers show good correlations (r = 0.87, 0.93, 0.91). The variability of computer CV measurements was comparable with that of the hand reader with the lowest variance. The coefficient of variation of residual volume and slope of alveolar plateau measurements are apparently reduced. The results demonstrate the adequacy and convenience of using the computer to analyse the Sb-N2 test and indicate that the automation allows for reduction of experimental errors and of test parameter variabilities. PMID:2601432

Melo, M F; Giannella Neto, A

1989-03-01

193

Testing Quantum Randomness in Single-Photon Polarization Measurements  

NASA Astrophysics Data System (ADS)

A binary sequence constructed from 17 million polarization measurements of single photons was subjected to a comprehensive set of tests for randomness. The polarization measurements were carried out using photon pairs from spontaneous parametric downconversion under low-intensity conditions similar to those of many optical quantum cryptography protocols. One member of each photon pair was used as a detection trigger, while the other was put into a superposition state of horizontal (H) and vertical (V) polarization, and then measured in the H-V basis. The resulting sequence of binary outcomes was subjected to a suite of fifteen tests developed at the National Institute of Standards and Technology (NIST) to assess the quality of algorithmic random-number generators. Several of these tests require many distinct sub-sequences of at least 1 million bits, with very low bias, in order to be meaningful. In this experiment the low bias of the collected sequence (0.04%) enabled all of the NIST tests to be applied directly to the polarization measurements themselves, without the use of numerical unbiasing procedures.

Branning, David; Bermudez, Matthew

2010-03-01

194

Random Vibration Testing of a Single Test Item with a Multiple Input Control System.  

National Technical Information Service (NTIS)

This paper develops an algorithm for a multiple shaker random vibration control system. The system is designed for several shakers driving a single test item with full cross-coupling control. The method allows for cross-coupled mechanical systems with par...

D. O. Smallwood

1981-01-01

195

Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations  

NASA Technical Reports Server (NTRS)

We have learned it is conceivable that the Neutral Mass Spectrometer on board the Lunarr Atmosphere Dust Environment Explorer (LADEE) could measure gases from surface-reflected Attitude Control System (ACS) thruster plume. At minimum altitude, the measurement would be maximized, and gravitational influence minimized ("short" time-of-flight (TOF) situation) Could use to verify aspects of thruster plume modeling Model the transient disturbance to NMS measurements due to ACS gases reflected from lunar surface Observe evolution of various model characteristics as measured by NMS Species magnitudes, TOF measurements, angular distribution, species separation effects

Woronowicz, Michael

2011-01-01

196

Marine diatoms grown in chemostats under silicate or ammonium limitation. II. Transient response of Skeletonema costatum to a single addition of the limiting nutrient  

Microsoft Academic Search

Skeletonema costatum was grown at different steady-state growth rates in ammonium or silicate-limited chemostats. The culture was perturbed from its steady-state condition by a single addition of the limiting nutrients ammonium or silicate. The transient response was followed by measuring nutrient disappearance of the liliting perturbation experiment indicate that three distinct modes of uptake of the limiting nutrient can be

H. L. Conway; P. J. Harrison; C. O. Davis

1976-01-01

197

Ablation with a single micropatterned KrF laser pulse: quantitative evidence of transient liquid microflow driven by the plume pressure gradient at the surface of polyesters  

Microsoft Academic Search

.   A microscopic flow of a transient liquid film produced by KrF laser ablation is evidenced on targets of PET and PEN. Experiments\\u000a were done by using single pulses of the excimer laser beam micropatterned with the aid of submicron projection optics and\\u000a grating masks. The samples of various crystalline states, ablated with a grating-forming beam (period ?=3.7 ?m), were precisely

F. Weisbuch; V. N. Tokarev; S. Lazare; D. Débarre

2003-01-01

198

Single Component Sorption-Desorption Test Experimental Design Approach Discussions  

SciTech Connect

A task was identified within the fission-product-transport work package to develop a path forward for doing testing to determine behavior of volatile fission products behavior and to engage members of the NGNP community to advise and dissent on the approach. The following document is a summary of the discussions and the specific approaches suggested for components of the testing. Included in the summary isare the minutes of the conference call that was held with INL and external interested parties to elicit comments on the approaches brought forward by the INL participants. The conclusion was that an initial non-radioactive, single component test will be useful to establish the limits of currently available chemical detection methods, and to evaluated source-dispersion uniformity. In parallel, development of a real-time low-concentration monitoring method is believed to be useful in detecting rapid dispersion as well as desorption phenomena. Ultimately, the test cycle is expected to progress to the use of radio-traced species, simply because this method will allow the lowest possible detection limits. The consensus of the conference call was that there is no need for an in-core test because the duct and heat exchanger surfaces that will be the sorption target will be outside the main neutron flux and will not be affected by irradiation. Participants in the discussion and contributors to the INL approach were Jeffrey Berg, Pattrick Calderoni, Gary Groenewold, Paul Humrickhouse, Brad Merrill, and Phil Winston. Participants from outside the INL included David Hanson of General Atomics, Todd Allen, Tyler Gerczak, and Izabela Szlufarska of the University of Wisconsin, Gary Was, of the University of Michigan, Sudarshan Loyalka and Tushar Ghosh of the University of Missouri, and Robert Morris of Oak Ridge National Laboratory.

Phil WInston

2011-09-01

199

49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.  

Code of Federal Regulations, 2013 CFR

...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

2013-10-01

200

Single tube support post thermal analysis and test results  

SciTech Connect

Cold mass structural supports used in prototype Superconducting Super Collider (SSC) 50 mm dipole magnets built at Fermilab and Brookhaven are adaptations of the design developed during the 40 mm design program at Fermilab. The design essentially consists of two composite tubes nested within each other as a means of maximizing the thermal path length. In addition it provides an ideal way to utilize materials best suited for the temperature range over which they must operate. Filament wound S-glass is used between 300K and 80K. Filament wound graphite fiber is used between 80K and 20K and between 20K and 4.5K. An alternate design for supports which uses a single composite tube has been developed at Fermilab and continues to be refined by the industrial contractors. The advantage of the new design is cost reduction due to a significantly simpler assembly and incorporation of many common parts. This report describes the thermal analysis and testing of a single composite tube support post whose function is identical to that of the current reentrant design.

Nicol, T.H.; Boroski, W.N.; Schoo, C.J.

1993-05-01

201

Comparing single-pool and multiple-pool designs regarding test security in computerized testing.  

PubMed

This article compares the use of single- and multiple-item pools with respect to test security against item sharing among some examinees in computerized testing. A simulation study was conducted to make a comparison among different pool designs using the item selection method of maximum item information with the Sympson-Hetter exposure control and content balance. The results from the simulation study indicate that two-pool designs have a better degree of resistance to item sharing than do the single-pool design in terms of measurement precision in ability estimation. This article further characterizes the conditions under which employing a multiple-pool design is better than using a single, whole pool in terms of minimizing the number of compromised items encountered by examinees under a randomized item selection method. Although no current computerized testing program endorses the randomized item selection method, the results derived in this study can shed some light on item pool designs regarding test security for all item selection algorithms, especially those that try to equalize or balance item exposure rates by employing a randomized item selection method locally, such as the a-stratified-with-b-blocking method. PMID:22218817

Zhang, Jinming; Chang, Hua-Hua; Yi, Qing

2012-09-01

202

Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts  

NASA Astrophysics Data System (ADS)

Aims: A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods: During two observing periods (Dec. 17, 2009 to Jan. 8, 2010 and Sep. 2 to Oct. 20, 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results: For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with ~50% or better probability with a few pointings of wide-field telescopes.

LIGO Scientific Collaboration; Virgo Collaboration; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Arain, M. A.; Araya, M. C.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballardin, G.; Ballmer, S.; Barker, D.; Barone, F.; Barr, B.; Barriga, P.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Basti, A.; Batch, J.; Bauchrowitz, J.; Bauer, Th. S.; Bebronne, M.; Behnke, B.; Beker, M. G.; Bell, A. S.; Belletoile, A.; Belopolski, I.; Benacquista, M.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Breyer, J.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brummit, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet-Castell, J.; Burmeister, O.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannizzo, J.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarin, E.; Chaibi, O.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chassande-Mottin, E.; Chelkowski, S.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J.; Clayton, J. H.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colacino, C. N.; Colas, J.; Colla, A.; Colombini, M.; Conte, A.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Coulon, J.-P.; Couvares, P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, R. M.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Davies, G.; Daw, E. J.; Day, R.; Dayanga, T.; DeRosa, R.; Debra, D.; Debreczeni, G.; Degallaix, J.; Del Pozzo, W.; Del Prete, M.; Dent, T.; Dergachev, V.; Derosa, R.; Desalvo, R.; Dhillon, V.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; De Paolo Emilio, M.; Di Virgilio, A.; Díaz, M.; Dietz, A.; Diguglielmo, J.; Donovan, F.; Dooley, K. L.; Dorsher, S.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Endröczi, G.; Engel, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Farr, W.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Flanigan, M.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fridriksson, J. K.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P. J.; Fyffe, M.; Galimberti, M.; Gammaitoni, L.; Ganija, M. R.; Garcia, J.; Garofoli, J. A.; Garufi, F.; Gáspár, M. E.; Gemme, G.; Geng, R.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Gray, N.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Greverie, C.; Grosso, R.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Ha, T.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Hayler, T.; Heefner, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Homan, J.; Hong, T.; Hooper, S.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Izumi, K.; Jacobson, M.; Jang, H.; Jaranowski, P.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.

2012-04-01

203

49 CFR 232.307 - Modification of the single car air brake test procedures.  

Code of Federal Regulations, 2013 CFR

...false Modification of the single car air brake test procedures. 232.307 Section...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND...307 Modification of the single car air brake test procedures. (a) Request....

2013-10-01

204

Detecting aseismic transients using seismicity  

NASA Astrophysics Data System (ADS)

Aseismic deformation transients occur in different tectonic context. In subduction zones, aseismic slip events are of paramount importance for understanding earthquake hazard, and for estimating the potential for future mega-thrust events. Aseismic slip is however difficult to detect except for the largest cases using GPS data. Here, we propose a systematic detection of aseismic deformation transients based on seismicity data alone. We search for transient increases in background seismicity rate, that would indicate the presence of an aseismic event. To that purpose, we make use of an ETAS model in space and time, to distinguish earthquakes due to background processes from aftershocks. We optimize the model parameters, and test the sensitivity of the results with changes in parameters. Given the 'best' model, we measure the statistical significance of the departure of the local (in time and space) background rate with the 'normal' background rate. Significant departure then indicates the need to temporary increase the background rate in order to explain the observed earthquake occurrences. We thus can single out such episodes of aseismic transients, and characterize their duration and spatial extent. Applying this method to the Aleutian subduction zone reveals several instances of aseismic deformation transients, at various spatial and temporal scales. We further investigate how these transients are organized along the subduction interface, and in time.

Reverso, T.; Marsan, D.; Helmstetter, A.

2013-12-01

205

Transient solid-fluid temperature responses in a spherical packed-bed thermal storage unit to a single-blow application of radial mass flow  

SciTech Connect

A spherical storage unit is inherently compact and free from heat losses across side walls. And, if the flow is radially inward, it has the additional advantage of presenting the bulk of its volume (with larger radius near the inlet) to the large temperature difference between the fluid stream and the solid bed prevailing near the entrance of all packed-bed units, especially during the transient stage. The present paper simulates numerically the transient temperature responses of both the fluid stream and the solid bed (two-phase) arranged in the form of a spherical shell, with a single-blow application of radial flow, considering the conductive effect in the solid, and with realistic boundary conditions.

Lu, P.C.; Kow, L.C.

1983-12-01

206

FLASH analysis of the MB-2 steady state, operational transient and stability tests  

SciTech Connect

This report describes testing performed in the Model Boiler No. 2 (MB-2) facility located at the Westinghouse Engineering Test Facility in Tampa, Florida which provided valuable data for validating steam generator computer code analytical models. MB-2 is scaled to represent a vertical tube Model F steam generator which is used in many commercial PWR plants. A major consideration in the MB-2 test rig design was to make it as prototypical as possible to the Model F commercial PWR steam generator.

Coffield, R.D.; Lincoln, F.W.; Johnson, E.G.

1993-11-01

207

Semiscale secondary transient investigations: results from Semiscale MOD2C feedwater and steam line break tests  

Microsoft Academic Search

A series of experiments was conducted in a scaled model of a pressurized water reactor (Semiscale MOD-2C) to investigate the system response to steam generator main steam line and bottom main feedwater line breaks. The two main steam line break tests simulated double-ended offset shears upstream and downstream of the flow restrictor. The three bottom main feedwater line break tests

Boucher

1985-01-01

208

The Mirrortron experiment: A proof of principle test for a method of generating high transient potentials  

SciTech Connect

The Mirrortron is a concept in which heavy ions are accelerated by a large local transient space potential that is produced in a hot electron plasma. The purpose of this experiment is to begin a proof of principle experiment to investigate the feasibility of producing this space potential and its associated electric field. If a large magnetic field is suddenly generated in a hot electron plasma with a loss-cone distribution, then potentials on the order of the electron temperature are expected. This potential lasts a few tens of nanoseconds. The investigation begins with a theoretical analysis of this phenomenon giving the space potential as a function of the applied magnetic field. The theory is further extended to cases of relativistic electron distributions. This is then followed by design work on a mirror confinement system for hot electrons. In this experiment a 50--100 keV electron temperature plasma is created with electron cyclotron resonance heating using two frequencies of relatively low microwave power. The microwaves are coupled to resonant frequencies of the vacuum chamber. The volume averaged plasma density is measured to be in the 10{sup 9} cm{sup {minus}3} range. A strap coil and a flat Blumlein transmission line pulse generator were developed to produce a 150 gauss field within 70 ns. The strap coil was placed at the midplane of the mirror field, where the field is 700 gauss. Based on theoretical estimates and computer simulations a 20 kV potential is expected. Measurement of this potential is derived from the modulation of the current of a monoenergetic electron beam after it passes through the high potential region. The variation in the beam energy allows bunching to occur in transit to the detector.

Douglass, S.R.

1993-09-01

209

Particle Tracking-Based Strategies For Simulating Transport in a Transient Groundwater Flow Field at Yucca Flat, Nevada Test Site, USA  

Microsoft Academic Search

Developing probabilistic-based calculations of contaminant concentrations over the next 1000 years at Yucca Flat, Nevada Test site, require tremendous computational effort in this highly complex hydrogeologic surface environment. The sources of contamination, underground nuclear tests conducted between 1951 and 1992, not only released radionuclides to the subsurface but also created abrupt, significant changes in rock properties and caused large transients

E. H. Keating; G. Srinivasan; Q. Kang; C. Li; Z. Dash; E. M. Kwicklis

2009-01-01

210

Numerical study of the SSME nozzle flow fields during transient operations: A comparison of the animated results with test  

NASA Technical Reports Server (NTRS)

A computational fluid dynamics (CFD) model has been applied to study the transient flow phenomena of the nozzle and exhaust plume of the Space Shuttle Main Engine (SSME), fired at sea level. The CFD model is a time accurate, pressure based, reactive flow solver. A six-species hydrogen/oxygen equilibrium chemistry is used to describe the chemical-thermodynamics. An adaptive upwinding scheme is employed for the spatial discretization, and a predictor, multiple corrector method is used for the temporal solution. Both engine start-up and shut-down processes were simulated. The elapse time is approximately five seconds for both cases. The computed results were animated and compared with the test. The images for the animation were created with PLOT3D and FAST and then animated with ABEKAS. The hysteresis effects, and the issues of free-shock separation, restricted-shock separation and the end-effects were addressed.

Wang, Ten-See; Dumas, Catherine

1993-01-01

211

Phase 3 integrated water recovery testing at MSFC: Single loop test results and lessons learned  

NASA Technical Reports Server (NTRS)

A series of tests has been conducted at the NASA Marshall Space Flight Center (MSFC) to evaluate the performance of the Space Station Freedom (SSF) water recovery system. Potable and urine reclamation processors were integrated with waste water generation equipment and sucessfully operated for a total of 144 days. This testing marked the first occasion in which the waste feed sources for the previous potable and hygiene loops were combined into a single loop and processed to potable water quality. Reclaimed potable water from the combined waste waters routinely met the SSF water quality specifications.In the last stage of testing, data was obtained that indicated that the water processor (WP) presterilizer may not be required to meet the potable water quality specification. The removal of the presterilizer from the Water Processor design would provide a significant power savings, though an increase in the residence time of the catalytic oxidation reactor may be required to meet the potable microbial and total Organic Carbon specifications. This paper summarizes the test objectives, system design, test activities/protocols, significant results/anomalies and major lessons learned.

Carter, Donald Layne; Bagdigian, Robert M.

1993-01-01

212

A REVIEW OF SINGLE SPECIES TOXICITY TESTS: ARE THE TESTS RELIABLE PREDICTORS OF AQUATIC ECOSYSTEM COMMUNITY RESPONSES?  

EPA Science Inventory

This document provides a comprehensive review to evaluate the reliability of indicator species toxicity test results in predicting aquatic ecosystem impacts, also called the ecological relevance of laboratory single species toxicity tests....

213

Dynamic recruitment of phospholipase C? at transiently immobilized GPI-anchored receptor clusters induces IP3-Ca2+ signaling: single-molecule tracking study 2  

PubMed Central

Clusters of CD59, a glycosylphosphatidylinositol-anchored receptor (GPI-AR), with physiological sizes of approximately six CD59 molecules, recruit G?i2 and Lyn via protein–protein and raft interactions. Lyn is activated probably by the G?i2 binding in the same CD59 cluster, inducing the CD59 cluster's binding to F-actin, resulting in its immobilization, termed stimulation-induced temporary arrest of lateral diffusion (STALL; with a 0.57-s lifetime, occurring approximately every 2 s). Simultaneous single-molecule tracking of GFP-PLC?2 and CD59 clusters revealed that PLC?2 molecules are transiently (median = 0.25 s) recruited from the cytoplasm exclusively at the CD59 clusters undergoing STALL, producing the IP3–Ca2+ signal. Therefore, we propose that the CD59 cluster in STALL may be a key, albeit transient, platform for transducing the extracellular GPI-AR signal to the intracellular IP3–Ca2+ signal, via PLC?2 recruitment. The prolonged, analogue, bulk IP3–Ca2+ signal, which lasts for more than several minutes, is likely generated by the sum of the short-lived, digital-like IP3 bursts, each created by the transient recruitment of PLC?2 molecules to STALLed CD59.

Suzuki, Kenichi G.N.; Fujiwara, Takahiro K.; Edidin, Michael; Kusumi, Akihiro

2007-01-01

214

Neuromodulation at single presynaptic boutons of cerebellar parallel fibers is determined by bouton size and basal action potential-evoked Ca transient amplitude  

PubMed Central

Most presynaptic terminals in the brain contain G-protein coupled receptors that function to reduce action potential-evoked neurotransmitter release. These neuromodulatory receptors, including those for glutamate, GABA, endocannabinoids and adenosine, exert a substantial portion of their effect by reducing evoked presynaptic Ca2+ transients. Many axons form synapses with multiple postsynaptic neurons, but it is unclear if presynaptic attenuation in these synapses is homogeneous, as suggested by population level Ca2+ imaging. We loaded Ca2+-sensitive dyes into cerebellar parallel fiber axons and imaged action potential-evoked Ca2+ transients in individual presynaptic boutons with application of three different neuromodulators and found that adjacent boutons on the same axon showed striking heterogeneity in their strength of attenuation. Moreover, attenuation was predicted by bouton size or basal Ca2+ response: smaller boutons were more sensitive to adenosine A1 agonist but less sensitive to CB1 agonist while boutons with high basal action potential-evoked Ca2+ transient amplitude were more sensitive to mGluR4 agonist. These results suggest that boutons within brief segment of a single parallel fiber axon can have different sensitivities towards neuromodulators and may have different capacities for both short-term and long-term plasticities.

Zhang, Wei; Linden, David J.

2010-01-01

215

Randomized single-subject experiments and statistical tests  

Microsoft Academic Search

The importance of intensive study of the individual subject in counseling research and the importance of the development of appropriate designs and analytical procedures for single- subject research has been recognized. Single-subject experiments are not always possible or ethical, but when they can be performed, treatment times should be randomly assigned to treatments, as this randomization is essential to provide

Eugene S. Edgington

1987-01-01

216

Randomized Single-Subject Experiments and Statistical Tests  

Microsoft Academic Search

The importance of intensive study of the individual subject in counseling research and the importance of the development of appropriate designs and analytical procedures for single-subject research has been recognized. Single-subject experiments are not always possible or ethical, but when they can be performed, treatment times should be randomly assigned to treatments, as this randomization is essential to provide the

Eugene S. Edgington

1987-01-01

217

Summary of air permeability data from single-hole injection tests in unsaturated fractured tuffs at the Apache Leap Research Site: Results of steady-state test interpretation  

SciTech Connect

This document summarizes air permeability estimates obtained from single hole pneumatic injection tests in unsaturated fractured tuffs at the Covered Borehole Site (CBS) within the larger apache Leap Research Site (ALRS). Only permeability estimates obtained from a steady state interpretation of relatively stable pressure and flow rate data are included. Tests were conducted in five boreholes inclined at 45{degree} to the horizontal, and one vertical borehole. Over 180 borehole segments were tested by setting the packers 1 m apart. Additional tests were conducted in segments of lengths 0.5, 2.0, and 3.0 m in one borehole, and 2.0 m in another borehole, bringing the total number of tests to over 270. Tests were conducted by maintaining a constant injection rate until air pressure became relatively stable and remained so for some time. The injection rate was then incremented by a constant value and the procedure repeated. The air injection rate, pressure, temperature, and relative humidity were recorded. For each relatively stable period of injection rate and pressure, air permeability was estimated by treating the rock around each test interval as a uniform, isotropic porous medium within which air flows as a single phase under steady state, in a pressure field exhibiting prolate spheroidal symmetry. For each permeability estimate the authors list the corresponding injection rate, pressure, temperature and relative humidity. They also present selected graphs which show how the latter quantities vary with time; logarithmic plots of pressure versus time which demonstrate the importance of borehole storage effects during the early transient portion of each incremental test period; and semilogarithmic plots of pressure versus recovery time at the end of each test sequence.

Guzman, A.G.; Geddis, A.M.; Henrich, M.J.; Lohrstorfer, C.F.; Neuman, S.P. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Water Resources

1996-03-01

218

Transient arthritis with positive tests for rheumatoid factor as presenting sign of shunt nephritis  

Microsoft Academic Search

Shunt nephritis is a rare complication of a chronically infected ventriculoatrial shunt. A 17 year old boy is described, with arthritis in both ankles and positive rheumatoid factor tests, who presented with symptoms of shunt nephritis. Blood cultures were positive for Staphylococcus epidermidis. The patient recovered completely after removal of the shunt and antibiotic treatment. Shunt nephritis should be considered

E J ter Borg; M H Van Rijswijk; C G Kallenberg

1991-01-01

219

Methodological factors involved in neonatal screening using transient-evoked otoacoustic emissions and automated auditory brainstem response testing.  

PubMed

The methodological factors involved in screening neonates for hearing loss, using transient-evoked otoacoustic emissions (TEOAEs) and automated auditory brainstem responses, have been evaluated from a large sample of neonates. The risk factors, commonly used to select babies for a targeted screen, have very little correlation with failing TEOAE testing. The parameters used to determine passing or failing the TEOAE test and the false alarm rate change markedly with age in the first few days of life as, of course, did the percentage of babies who failed the test. The stimulus level used was the default setting for the Otodynamics equipment but the stimulus level measured in the ear canal decreased over the first 140 h of life. It is thought that this reflects the impedance changes in outer and middle ears and possible changes in middle ear dynamics. The methodological variables investigated here can illuminate some of the differences in previous reports of neonatal screening, in particular the reported hit and false alarm rates. PMID:12948603

Thornton, A Roger D; Kimm, Lindsay; Kennedy, Colin R

2003-08-01

220

Loss-of-feedwater, steam generator tube rupture, and steam line break experiments: Steam generator transient response test program: Interim report  

SciTech Connect

The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results. Two LOF tests were analyzed in detail. Both tests were initiated from 100% power condition by shutting off the main feedwater flow. In LOF Test No. 1, the remaining boundary conditions were kept constant while in LOF Test No. 2, the power was rapidly reduced to 3%. The results show that the primary to secondary heat transfer becomes degraded when the collapsed water liquid level in the bundle region falls below approximately 50 inches. The SGTR test analyzed in detail - SGTR Test No. 2 - simulated the post-reactor-trip portion of the SGTR transient (T/sub prim/ = 560/sup 0/F). The transient was initiated by starting the SGTR flow injection and simultaneously shutting off the auxiliary feedwater. The water level rose and flooded the dryer to its mid-elevation by the end of the test. The primary carry-over was shown to be less than 0.4% of the tracer mass injected into the secondary side by the SGTR flow. SGTR Test No. 3 investigated the response of the intact steam generator. Reverse heat transfer and low heat flow conditions were simulated. The results have demonstrated the occurrence of temperature stratification in the secondary water which lasted for about 800 seconds.

Mendler, O.J.; Takeuchi, K.; Young, M.Y.

1987-01-01

221

Using Transient\\/Persistent Errors to Develop Automated Test Oracles for Event-Driven Software  

Microsoft Academic Search

Today's software-intensive systems contain an important class of software, namely event-driven software (EDS). All EDS take events as input, change their state, and (perhaps) output an event sequence. EDS is typically implemented as a collection of event-handlers designed to respond to individual events. The nature of EDS creates new challenges for test automation. In this paper, we focus on those

Atif M. Memon; Qing Xie

2004-01-01

222

Radiation-Induced Transient Effects in Near Infrared Focal Plane Arrays  

NASA Technical Reports Server (NTRS)

This viewgraph presentation describes a test simulate the transient effects of cosmic ray impacts on near infrared focal plane arrays. The objectives of the test are to: 1) Characterize proton single events as function of energy and angle of incidence; 2) Measure charge spread (crosstalk) to adjacent pixels; 3) Assess transient recovery time.

Reed, Robert A.; Pickel, J.; Marshall, P.; Waczynski, A.; McMurray, R.; Gee, G.; Polidan, E.; Johnson, S.; McKeivey, M.; Ennico, K.; Johnson, R.

2004-01-01

223

Single Particle Friction Tests with Cellulose Acetate Sphere Samples.  

National Technical Information Service (NTIS)

This report represents a detailed account of all the experimental work carried out for LLNL using the ''single particle shear cell'' in the department of Chemical & Process Engineering of Surrey University, Guildford, United Kingdom. Experimental work wit...

U. Tuezen

1989-01-01

224

Unraveling the exciton quenching mechanism of quantum dots on antimony-doped SnO? films by transient absorption and single dot fluorescence spectroscopy.  

PubMed

Integrating quantum dots (QDs) into modern optoelectronic devices requires an understanding of how a transparent conducting substrate affects the properties of QDs, especially their excited-state dynamics. Here, the exciton quenching dynamics of core/multishell (CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML)) quantum dots deposited on glass, tin oxide (SnO?), and antimony (Sb)-doped tin oxide (ATO) films are studied by transient absorption and single QD fluorescence spectroscopic methods. By comparing ensemble-averaged fluorescence decay and transient absorption kinetics, we show that, for QDs on SnO?, the exciton is quenched by electron transfer from the QD to SnO?. At the QD-ATO interface, much faster exciton quenching rates are observed and attributed to fast Auger recombination in charged QDs formed by Fermi level equilibration between the QD and n-doped ATO. Single QDs on SnO? and ATO show similar blinking dynamics with correlated fluctuations of emission intensities and lifetimes. Compared to QDs on SnO?, QDs on ATO films show larger variation of average exciton quenching rates, which is attributed to a broad distribution of the number of charges and nature of charging sites on the QD surface. PMID:23281781

Song, Nianhui; Zhu, Haiming; Liu, Zheng; Huang, Zhuangqun; Wu, David; Lian, Tianquan

2013-02-26

225

Mechanical testing of large thallium doped sodium iodide single crystals  

NASA Technical Reports Server (NTRS)

The findings of mechanical tests performed on five thallium-doped sodium iodide NaI(Tl) crystals are presented. These crystals are all in the shape of circular flat plates, 20.0 in. in diameter an d0.5 in. thick. The test setup, testing procedure, and the test data are presented. Large crystals exhibit a high degree of material plasticity, as well as a much higher strength than previously anticipated, on the order of 500 psi. Also revealed from the testing is the fact that crystal with a large number of grain boundaries developed less plasticity, and therefore less permanent deformation, than those with fewer grain boundaries.

Lee, H. M.

1985-01-01

226

Test report for single event effects of the 80386DX microprocessor  

NASA Technical Reports Server (NTRS)

The Jet Propulsion Laboratory Section 514 Single Event Effects (SEE) Testing and Analysis Group has performed a series of SEE tests of certain strategic registers of Intel's 80386DX CHMOS 4 microprocessor. Following a summary of the test techniques and hardware used to gather the data, we present the SEE heavy ion and proton test results. We also describe the registers tested, along with a system impact analysis should these registers experience a single event upset.

Watson, R. Kevin; Schwartz, Harvey R.; Nichols, Donald K.

1993-01-01

227

Pulsed chemical laser technology-development test plan: single-pulse diagnostic testing  

SciTech Connect

Single-pulse DF and DF/CO/sub 2/ transfer laser testing will be conducted to expand the data base for verification and extension of performance scaling relations. Scaling relations are currently based on the analytical effort completion under Task I and the comparison of this analysis with the available data. Tests will explore the effects on performance of gas composition with constituents including F/sub 2/, D/sub 2/, O/sub 2/, HF, NF/sub 2/, He, N/sub 2/, and CO/sub 2/ at both DF and CO/sub 2/ wavelengths. Tests will explore the nature of the medium in terms of F-atom initiation level and gain, the nature of the initiating electron-beam source in terms of energy deposition level and uniformity and pulse length, and laser yield in terms of total energy, pulse shape, and time resolved spectra. The system will operate at pressures ranging from 200 to 760 torr.

Moran, J.P.

1986-04-15

228

COBRA-WC: a version of COBRA for single-phase multiassembly thermal hydraulic transient analysis. [LMFBR  

SciTech Connect

The objective of this report is to provide the user of the COBRA-WC (Whole Core) code a basic understanding of the code operation and capabilities. Included in this manual are the equations solved and the assumptions made in their derivations, a general description of the code capabilities, an explanation of the numerical algorithms used to solve the equations, and input instructions for using the code. Also, the auxiliary programs GEOM and SPECSET are described and input instructions for each are given. Input for COBRA-WC sample problems and the corresponding output are given in the appendices. The COBRA-WC code has been developed from the COBRA-IV-I code to analyze liquid Metal Fast Breeder Reactor (LMFBR) assembly transients. It was specifically developed to analyze a core flow coastdown to natural circulation cooling.

George, T.L.; Basehore, K.L.; Wheeler, C.L.; Prather, W.A.; Masterson, R.E.

1980-07-01

229

33rd Scale Tank Testing, Single WEC Assessment.  

National Technical Information Service (NTIS)

Columbia Power Technologies (ColPwr) and Oregon State University (OSU) jointly conducted a series of tests in the Tsunami Wave Basin (TWB) at the O.H. Hinsdale Wave Research Laboratory (HWRL). These tests were run between November 2010 and February 2011. ...

2012-01-01

230

Test E3 on High-Energy Transient Meltdown of Irradiated UO sub 2 in a TREAT Mark-II Loop.  

National Technical Information Service (NTIS)

Three ''gassy'' irradiated UO sub 2 pins were run past failure in a 35-ms natural TREAT transient in TREAT loop Test E3 to guide in choosing between two modeling assumptions regarding energy conversion from sodium vaporization in an irradiated-oxide-fuel/...

L. W. Deitrich C. E. Dickerman F. L. Willis

1977-01-01

231

Qualification test procedures and results for Honeywell solar collector subsystem, single-family residence  

NASA Technical Reports Server (NTRS)

The test procedures and results in qualifying the Honeywell single family residence solar collector subsystem are presented. Testing was done in the following areas: pressure, service loads, hail, solar degradation, pollutants, thermal degradation, and outgassing.

1977-01-01

232

Honeywell radiation hardened 32-bit processor single event effects test results  

Microsoft Academic Search

We will present single event effects test results for the Honeywell radiation hardened 32-bit processor. The processor was tested at board-level while executing a signal and data processing benchmark suite

S. C. Leavy; Jeffrey A. Mogensen; Thomas S. Smith; G. J. Freitfeld; Julie Brichacek

1998-01-01

233

Subsurface damage of single crystalline silicon carbide in nanoindentation tests.  

PubMed

The response of single crystalline silicon carbide (SiC) to a Berkovich nanoindenter was investigated by examining the indents using a transmission electron microscope and the selected area electron diffraction technique. It was found that the depth of indentation-induced subsurface damage was far larger than the indentation depth, and the damaging mechanism of SiC was distinctly different from that of single crystalline silicon. For silicon, a broad amorphous region is formed underneath the indenter after unloading; for SiC, however, no amorphous phase was detected. Instead, a polycrystalline structure with a grain size of ten nanometer level was identified directly under the indenter tip. Micro cracks, basal plane dislocations and possible cross slips were also found around the indent. These finding provide useful information for ultraprecision manufacturing of SiC wafers. PMID:21138038

Yan, Jiwang; Gai, Xiaohui; Harada, Hirofumi

2010-11-01

234

Ablation with a single micropatterned KrF laser pulse: quantitative evidence of transient liquid microflow driven by the plume pressure gradient at the surface of polyesters  

NASA Astrophysics Data System (ADS)

A microscopic flow of a transient liquid film produced by KrF laser ablation is evidenced on targets of PET and PEN. Experiments were done by using single pulses of the excimer laser beam micropatterned with the aid of submicron projection optics and grating masks. The samples of various crystalline states, ablated with a grating-forming beam (period ?=3.7 ?m), were precisely measured by atomic force microscopy, in order to evidence any deviation from the ablation behavior predicted by the current theory (combination of ablation curve and beam profile). This was confirmed by comparing various behaviors dependent on the polymer nature (PC, PET and PEN). PC is a normally ablating polymer in the sense that the ablated profile can be predicted with previous theory neglecting liquid-flow effects. This case is called `dry' ablation and PC is used as a reference material. But, for some particular samples like crystalline PET, it is revealed that during ablation a film of transient liquid, composed of various components, which are discussed, can flow under the transient action of the gradient of the pressure of the ablation plume and resolidify at the border of the spot after the end of the pulse. This mechanism is further supported by a hydrodynamics theoretical model in which a laser-induced viscosity drop and the gradient of the plume pressure play an important role. The volume of displaced liquid increases with fluence (0.5 to 2 J/cm2) and satisfactory quantitative agreement is obtained with the present model. The same experiment done on the same PET polymer but prepared in the amorphous state does not show microflow, and such an amorphous sample behaves like the reference PC (`dry' ablation). The reasons for this surprising result are discussed.

Weisbuch, F.; Tokarev, V. N.; Lazare, S.; Débarre, D.

235

The mechanism of the transient depression of the erythropoietic rate induced in the rat by a single injection of uranyl nitrate  

SciTech Connect

With the purpose of assessing the effect of uranyl nitrate (UN) on the rate of erythropoiesis, 1 mg/kg of the compound was injected iv to adult female Wistar rats. The dosing vehicle was injected into control animals. A single injection of UN induced a transient depression of the rate of red cell volume /sup 59/Fe uptake, which reached its lowest value (68% depression) by the seventh postinjection day. By 14 days, /sup 59/Fe incorporation had returned to normal. The amount of iron going to erythroid tissue per hour, reticulocyte count, and immunoreactive erythropoietin concentration in both plasma and kidney extracts were also significantly depressed in UN-treated rats in relation to these values in vehicle-injected rats by the seventh postinjection day. Dose-response curves for exogenous erythropoietin (Epo) performed in polycythemic intact and UN-treated rats 7 days after drug injection revealed a significant depression of the response in UN-injected animals. Moreover, bone marrow cells obtained from rats pretreated with UN formed a reduced number of erythroid colonies in vitro in response to Epo. Therefore, possible mechanisms for the observed transient depression in the rate of erythropoiesis associated with acute UN treatment include decreased Epo production and direct or indirect damage of erythroid progenitor cells.

Giglio, M.J.; Brandan, N.; Leal, T.L.; Bozzini, C.E.

1989-06-15

236

Transient U wave inversion during treadmill exercise testing in patients with left anterior descending coronary artery disease.  

PubMed

The transient U wave inversion during exercise is specific for detecting left anterior descending coronary artery (LAD) disease. In a homogeneous patient group restricted to LAD disease, however, the significance of the electrocardiographic finding has not yet been clarified. Thus, clinical characteristics in patients with angiographically documented one-vessel disease of the LAD and exercise-induced U wave inversion were delineated. Symptom-limited treadmill exercise testing was performed in 60 patients (43 men, 17 women; mean age 64 +/- 8 years) with angina pectoris whose culprit lesion was located only in the LAD. U wave polarity and amplitude were determined before, during, and after exercise with the P-Q segment as the isoelectric line. Exercise-induced transient U wave inversion was defined as positive when there was a discrete negative deflection > or = 0.05 mV within the T-P segment. Of all patients, 16 (27%) had exercise-induced U wave inversion. There were no differences in age, male gender, antianginal medication use, and coronary angiographic data between the two patients groups: patients with and without U wave inversion. Heart rate and double product of heart rate and systemic systolic blood pressure at peak exercise were also similar. Prevalence of abnormal exercise-induced S-T segment shift was 94% (15 of 16 patients) and 61% (27 of 44 patients) of patients with and without U wave inversion, respectively. The difference was statistically significant (p = 0.02). Among patients with exercise-induced S-T segment shift, the proportion of patients with S-T segment elevation to all the patients was larger in patients with U wave inversion than in patients without U wave inversion [3 (20%) of 15 patients vs 0 (0%) of 27 patients, p = 0.03)]. In conclusion, the exercise-induced U wave inversion in patients with one-vessel disease of the LAD indicates the severe degree of myocardial ischemia induced in the territory perfused by the LAD. However, the electrocardiographic finding does not appear to have independent significance since it closely correlates with the presence of S-T segment shift. PMID:10917582

Kodama, K; Hiasa, G; Ohtsuka, T; Ikeda, S; Hashida, H; Kuwahara, T; Hara, Y; Shigematsu, Y; Hamada, M; Hiwada, K

2000-07-01

237

Methods of Testing Oils in Single Cylinder Engines.  

National Technical Information Service (NTIS)

Discussed is the reliability of testing of oils with additives in the Pitter AV-1 apparatus with a diesel engine for evaluation of detergent properties by the standard method PI 175/64 and in the Pitter W-1 apparatus with a carbureted engine for evaluatio...

V. F. Filippov M. E. Zhurina K. N. Nizhnik

1970-01-01

238

Subcooler assembly for SSC single magnet test program  

SciTech Connect

A subcooler assembly has been designed, constructed and installed in the MAGCOOL magnet test area at Brookhaven National Laboratory. Since July 1989, it has been used for testing SSC magnets. This subcooler assembly and cryogenic system are the first of its kind ever built. Today, with more than 5000 hours of operating time, the subcooler has proved to be a reliable unit with individual components meeting design expectations. The lowest temperatures achieved with one SSC dipole are 3.0 K at the suction of the cold vacuum pump and 3.2 K at the return of the magnet. The system performs well in both steady state operation and during magnet quench, subcooling, cooldown and warmup. 4 refs., 7 figs.

Wu, K.C.; Brown, D.P.; Sondericker, J.H.; Farah, Y.; Zantopp, D.; Nicoletti, A.

1991-01-01

239

Single point random modal test technology application to failure detection  

NASA Technical Reports Server (NTRS)

Frequency response function data, normally acquired as a data base for use in development of empirically based mode shapes, has additional utility. Comparison and analysis of frequency response function data sets obtained prior to and after environmental tests of an Orbiter body flap have enabled identification of structural damage that was not detected by conventional visual, X-ray, and ultrasonic inspections. The analyses and conclusions reported demonstrate that specific damaged areas within a relatively complex structure identified on a timely basis.

West, W. M., Jr.

1982-01-01

240

Test procedures and instructions for single shell tank saltcake cesium removal with crystalline silicotitanate  

SciTech Connect

This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Single Shell Tank Saltcake from tanks 24 t -BY- I 10, 24 1 -U- 108, 24 1 -U- 109, 24 1 -A- I 0 1, and 24 t - S-102, in a bench-scale column. The cesium sorbent to be tested is crystalline siticotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-024, Hanford Single Shell Tank Saltcake Cesium Removal Test Plan.

Duncan, J.B.

1997-01-07

241

Dynamic tensile test of single PET textile cables  

NASA Astrophysics Data System (ADS)

The tyres conception involves for certain applications, the use of textile cables as reinforcement. During its use, the tyre undergoes temperatures variations and dynamic loading rates. The consideration of these conditions during the numeric simulations requires the knowledge of the sensitivity of the mechanical behaviour to loading rate and temperature. In this paper, we developed an experimental methodology for testing textile cable up to high strain rate. The main difficulty of testing cables is the optimization of cable fixing on the machine. For that purpose, we adapted the solution of fixing by progressive binding already used in quasi-static, while taking into account constraints inherent to high strain tests. Firstly, the mass of grips was decreased in order to get force signal less sensitive to grips inertia. The method was developed on a high speed hydraulic machine equipped with a thermal enclosure. The investigated temperatures and strain rates range from room temperature to 373 ?K (100 ?C) and from 0,01 to 100/s, respectively. In addition, the hydraulic machine was equipped with a high speed video camera. The obtained images were analysed by a tracking technique to measure the average strain in the cable (from 50 to 20000 f/s).

Guégan, P.; Othman, R.; Pasco, F.; Bruant, R.

2012-08-01

242

Prenatal invasive testing: a 13-year single institution experience.  

PubMed

Abstract Objectives: To analyze trends in screening and invasive prenatal diagnosis over a 13-year period in relation to changes in the national prenatal screening policy. Methods: Fetal karyotypes obtained following 11?045 prenatal invasive procedures between January 1999 and December 2011 were retrospectively reviewed. Referral indications were classified as medical and non-medical (anxiety). The number of tests per relevant chromosomal abnormalities (CA) detected in both groups adjusted for indication was calculated. Results: A total of 414 CA were detected (3.8%), 355 of which were considered clinically significant. The percentage of invasive procedures has declined from 49% to 12%, although cases referred by anxiety have increased from 22% to 55%. A total of 3129 invasive procedures did not have any medical indication (28%) and 13 relevant CA (0.42%) were found in this group. In this low-risk series, the index "number of invasive testing needed to detect 1 relevant CA" adjusted for indication was 241. Conclusions: Changes in our national prenatal policy through this 13-year period show an increasing efficiency of prenatal detection of CA. However, despite the intensifying screening policies, low-risk pregnant women show a growing demand for prenatal invasive testing and a baseline risk for cytogenetic abnormality of 1/241. PMID:24131234

Comas, Carmen; Echevarria, Mónica; Rodríguez, Ignacio; Serra, Bernat; Cirigliano, Vincenzo

2014-08-01

243

Neutronics, steady-state, and transient analyses for the Poland MARIA reactor for irradiation testing of LEU lead test fuel assemblies from CERCA : ANL independent verification results.  

SciTech Connect

The MARIA reactor at the Institute of Atomic Energy (IAE) in Swierk (30 km SE of Warsaw) in the Republic of Poland is considering conversion from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel assemblies (FA). The FA design in MARIA is rather unique; a suitable LEU FA has never been designed or tested. IAE has contracted with CERCA (the fuel supply portion of AREVA in France) to supply 2 lead test assemblies (LTA). The LTAs will be irradiated in MARIA to burnup level of at least 40% for both LTAs and to 60% for one LTA. IAE may decide to purchase additional LEU FAs for a full core conversion after the test irradiation. The Reactor Safety Committee within IAE and the National Atomic Energy Agency in Poland (PAA) must approve the LTA irradiation process. The approval will be based, in part, on IAE submitting revisions to portions of the Safety Analysis Report (SAR) which are affected by the insertion of the LTAs. (A similar process will be required for the full core conversion to LEU fuel.) The analysis required was established during working meetings between Argonne National Laboratory (ANL) and IAE staff during August 2006, subsequent email correspondence, and subsequent staff visits. The analysis needs to consider the current high-enriched uranium (HEU) core and 4 core configurations containing 1 and 2 LEU LTAs in various core positions. Calculations have been performed at ANL in support of the LTA irradiation. These calculations are summarized in this report and include criticality, burn-up, neutronics parameters, steady-state thermal hydraulics, and postulated transients. These calculations have been performed at the request of the IAE staff, who are performing similar calculations to be used in their SAR amendment submittal to the PAA. The ANL analysis has been performed independently from that being performed by IAE and should only be used as one step in the verification process.

Garner, P. L.; Hanan, N. A. (Nuclear Engineering Division)

2011-06-07

244

Testing of a single cell cylindrical inverted converter  

NASA Astrophysics Data System (ADS)

A Cylindrical Inverted Converter (CIC), made by Lutch, with the emitter on the outside was tested in a vacuum furnace supplying radiant heat to the emitter outer surface. The collector, coaxial with the emitter, has an integral heat pipe with sodium as the working fluid, which carries the heat dissipated in the collector to a radiating area with a coating of alumina and sub-stoichiometric TiO2. The CIC is a proof-of-principle device which will lead to the development of multi-cell inverted converter assemblies for space solar power systems. The thermionic performance at emitter temperatures of 1800 and 1900 K is presented. .

Desplat, Jean-Louis

2002-01-01

245

Rhyme test performance of ACSB (amplitude compandored single sideband), narrow band, and FM radios  

NASA Astrophysics Data System (ADS)

In this fifth of nine reports concerning spectrum efficient technologies, amplitude compandored single sideband (ACSB) radios and narrowband (NB) radios using amplitude and frequency compandors are compared with conventional frequency modulation (FM) radios by using the Dynastat Corporation's diagnostic rhyme test (DRT). This test provides a measure of the intelligibility of a received signal based on listener identification of initial consonant sounds of single syllable words. The test also provides subjective ratings of several aspects of signal quality based on listeners' personal preference.

Wala, P.

1980-03-01

246

PM DEVELOPMENT TASK 5.0 LOCAL BOILING HEAT TRANSFER TESTS. Single Tube Heat Transfer and Pressure Drop Tests  

Microsoft Academic Search

Local boiling heat transfer and pressure drop data were obtained on the ; inside of a single tube test section which was dimensionally identical to a PM-1 ; fuel element. A total of 242 experimental runs were performed, including l32 ; local boiling runs. The test parameters covered were: system pressure from 800 ; to l500 psia; flow rates of

J. J. Jr. Jicha; S. Frank

1961-01-01

247

DESIGN AND PERFORMANCE OBJECTIVES OF THE SINGLE CELL TEST SYSTEM FOR SO2 DEPOLARIZED ELECTROLYZER DEVELOPMENT  

SciTech Connect

The single cell test system development for the SRNL sulfur dioxide-depolarized electrolyzer has been completed. Operating experience and improved operating procedures were developed during test operations in FY06 and the first quarter of FY07. Eight different cell configurations, using various MEA designs, have been tested. The single cell test electrolyzer has been modified to overcome difficulties experienced during testing, including modifications to the inlet connection to eliminate minute acid leaks that caused short circuits. The test facility was modified by adding a water bath for cell heating, thus permitting operation over a wider range of flowrates and cell temperatures. Modifications were also identified to permit continuous water flushing of the cathode to remove sulfur, thus extending operating time between required shutdowns. This is also expected to permit a means of independently measuring the rate of sulfur formation, and the corresponding SO{sub 2} flux through the membrane. This report contains a discussion of the design issues being addressed by the single cell test program, a test matrix being conducted to address these issues, and a summary of the performance objectives for the single cell test system. The current primary objective of single cell test system is to characterize and qualify electrolyzer configurations for the following 100-hour longevity tests. Although the single cell test system development is considered complete, SRNL will continue to utilize the test facility and the single cell electrolyzer to measure the operability and performance of various cell design configurations, including new MEA's produced by the component development tasks.

Steimke, J

2007-01-15

248

Parametric Testing of Chevrons on Single Flow Hot Jets  

NASA Technical Reports Server (NTRS)

A parametric family of chevron nozzles have been studied, looking for relationships between chevron geometric parameters, flow characteristics, and far-field noise. Both cold and hot conditions have been run at acoustic Mach number 0.9. Ten models have been tested, varying chevron count, penetration, length, and chevron symmetry. Four comparative studies were defined from these datasets which show: that chevron length is not a major impact on either flow or sound; that chevron penetration increases noise at high frequency and lowers it at low frequency, especially for low chevron counts; that chevron count is a strong player with good low frequency reductions being achieved with high chevron count without strong high frequency penalty; and that chevron asymmetry slightly reduces the impact of the chevron. Finally, it is shown that although the hot jets differ systematically from the cold one, the overall trends with chevron parameters is the same.

Bridges, James; Brown, Clifford A.

2004-01-01

249

Single photons in an imperfect array of beam-splitters: interplay between percolation, backscattering and transient localization  

NASA Astrophysics Data System (ADS)

Photons in optical networks can be used in multi-path interferometry and various quantum information processing and communication protocols. Large networks, however, are often not free from defects, which can appear randomly between the lattice sites and are caused either by production faults or deliberate introduction. In this work we present numerical simulations of the behaviour of a single photon injected into a regular lattice of beam-splitting components in the presence of defects that cause perfect backward reflections. We find that the photon dynamics is quickly dominated by the backscattering processes, and a small fraction of reflectors in the paths of the beam-splitting array strongly affects the percolation probability of the photon. We carefully examine such systems and show an interesting interplay between the probabilities of percolation, backscattering and temporary localization. We also discuss the sensitivity of these probabilities to lattice size, timescale, injection point, fraction of reflectors and boundary conditions.

Chandrashekar, C. M.; Melville, S.; Busch, Th

2014-04-01

250

GPI-anchored receptor clusters transiently recruit Lyn and G? for temporary cluster immobilization and Lyn activation: single-molecule tracking study 1  

PubMed Central

The signaling mechanisms for glycosylphosphatidylinositol-anchored receptors (GPI-ARs) have been investigated by tracking single molecules in living cells. Upon the engagement or colloidal gold–induced cross-linking of CD59 (and other GPI-ARs) at physiological levels, CD59 clusters containing three to nine CD59 molecules were formed, and single molecules of G?i2 or Lyn (GFP conjugates) exhibited the frequent but transient (133 and 200 ms, respectively) recruitment to CD59 clusters, via both protein–protein and lipid–lipid (raft) interactions. Each CD59 cluster undergoes alternating periods of actin-dependent temporary immobilization (0.57-s lifetime; stimulation-induced temporary arrest of lateral diffusion [STALL], inducing IP3 production) and slow diffusion (1.2 s). STALL of a CD59 cluster was induced right after the recruitment of G?i2. Because both G?i2 and Lyn are required for the STALL, and because Lyn is constitutively recruited to CD59 clusters, the STALL of CD59 clusters is likely induced by the G?i2 binding to, and its subsequent activation of, Lyn within the same CD59 cluster.

Suzuki, Kenichi G.N.; Fujiwara, Takahiro K.; Sanematsu, Fumiyuki; Iino, Ryota; Edidin, Michael; Kusumi, Akihiro

2007-01-01

251

Advanced development of the spectrum sciences Model 5005-TF, single-event test fixture  

SciTech Connect

This report summarizes the advanced development of the Spectrum Sciences Model 5005-TF, Single-Event Test Fixture. The Model 5005-TF uses a Californium-252 (Cf-252) fission-fragment source to test integrated circuits and other devices for the effects of single-event phenomena. Particle identification methods commonly used in high-energy physics research and nuclear engineering have been incorporated into the Model 5005-TF for estimating the particle charge, mass, and energy parameters. All single-event phenomena observed in a device under test (DUT) are correlated with an identified fission fragment, and its linear energy transfer (LET) and range in the semiconductor material of the DUT.

Ackermann, M.R.; Browning, J.S. (Sandia National Labs., Albuquerque, NM (USA)); Hughlock, B.W. (Boeing Aerospace and Electronics Co., Seattle, WA (USA)); Lum, G.K. (Lockheed Missiles and Space Co., Sunnyvale, CA (USA)); Tsacoyeanes, W.C. (Draper (Charles Stark) Lab., Inc., Cambridge, MA (USA)); Weeks, M.D. (Spectrum Sciences, Inc., Santa Clara, CA (USA))

1990-09-01

252

Determination of carbon fiber adhesion to thermoplastic polymers using the single fiber/matrix tensile test  

NASA Technical Reports Server (NTRS)

The single fiber adhesion shear test has been adapted to testing the adhesion between carbon fiber and thermoplastic polymers. Tests of three thermoplastics, polycarbonate, polyphenylene oxide and polyetherimide indicate the shear adhesion strength is significantly less than of an epoxy polymer to the same carbon fiber.

Bascom, W. D.; Cordner, L. W.; Hinkley, J. L.; Johnston, N. J.

1986-01-01

253

I.v. cocaine induces rapid, transient excitation of striatal neurons via its action on peripheral neural elements: single-cell, iontophoretic study in awake and anesthetized rats.  

PubMed

Cocaine's (COC) direct interaction with the dopamine (DA) transporter is usually considered the most important action underlying the psychomotor stimulant and reinforcing effects of this drug. However, some physiological, behavioral and psycho-emotional effects of COC are very rapid and brief and they remain intact during DA receptor blockade, suggesting possible involvement of peripheral non-DA neural mechanisms. To assess this issue, single-unit recording with microiontophoresis was used to examine changes in impulse activity of dorsal and ventral striatal neurons to i.v. COC (0.25-0.5 mg/kg) in the same rats under two conditions: awake with DA receptor blockade and anesthetized with urethane. In the awake preparation approximately 70% striatal neurons showed rapid and transient (latency approximately 6 s, duration approximately 15 s) COC-induced excitations. These effects were stronger in ventral than dorsal striatum. During anesthesia, these phasic effects were fully blocked and COC slowly decreased neuronal discharge rate. Cocaine-methiodide (COC-M), a derivative that cannot cross the blood-brain barrier, also caused phasic excitations in the awake, but not anesthetized condition. In contrast to regular COC, COC-M had no tonic effect on discharge rate in either preparation. Most striatal neurons that were phasically excited by both COC forms also showed short-latency excitations during tail-touch and tail-pinch in the awake preparation, an effect strongly attenuated during anesthesia. Finally, most striatal neurons that in awake conditions were phasically excited by somato-sensory stimuli and COC salts were also excited by iontophoretic glutamate (GLU). Although striatal neurons were sensitive to GLU in both preparations, the response magnitude at the same GLU current was higher in awake than anesthetized conditions. These data suggest that in awake animals i.v. COC, like somato-sensory stimuli, transiently excites striatal neurons via its action on peripheral neural elements and rapid neural transmission. While the nature of these neuronal elements needs to be clarified using other analytical techniques, they might involve voltage-gated K(+) and Na(+) channels, which have a high affinity for COC and are located on terminals of visceral sensory nerves that densely innervate peripheral vessels. Therefore, along with direct action on specific brain substrates, central excitatory effects of COC may occur via indirect action, involving afferents of visceral sensory nerves and rapid neural transmission. By providing a rapid sensory signal and triggering transient neural activation, such a peripherally triggered action might play a crucial role in the sensory effects of COC, thus contributing to learning and development of drug-taking behavior. PMID:17706878

Kiyatkin, E A; Brown, P L

2007-09-21

254

RELAP5\\/MOD3 Analysis of Transient Steam-Generator Behavior During Turbine Trip Test of a Prototype Fast Breeder Reactor MONJU  

Microsoft Academic Search

In order to develop a thermal-hydraulic model of the steam-generator (SG) to simulate transient phenomena in the sodium cooled fast breeder reactor (FBR) MONJU, Japan Nuclear Energy Safety Organization (JNES) verified the SG model using the RELAP5\\/MOD3 code against the results of the turbine trip test at a 40% power load of MONJU. The modeling by using RELAP5 was considered

Yoshihisa Shindo; Hiroshi Endo; Tomoko Ishizu; Kazuo Haga

2006-01-01

255

Pain perception and performance of three devices for single-site allergen skin testing.  

PubMed

Skin testing remains the preferred method for most allergists for establishing the presence of allergen sensitization. This study examined the performance of a new single-site skin test device that incorporates initial pressure to reduce the sensation of pain. Comparators were a conventional skin testing system and a smallpox needle. Twenty subjects were tested on the back, four sites with histamine and four sites with saline with each of the three skin testing devices. The single-site skin test device was applied with downward pressure, the conventional skin testing system, and smallpox needle (SPN) by pricking at a 45°angle. Outcomes were size and reproducibility of the skin test reactions and discomfort, as graded by the subject. The whealing responses to histamine were larger with the conventional skin testing system than with the single-site skin test device and both produced larger wheals than the SPN. The conventional skin testing system also produced greater intrasubject variability. Only the conventional skin testing system produced wheals of >3 mm with saline. There was no significant difference in perception of pain, which was low with all three devices. All three devices were well tolerated, without a significant difference in perception of discomfort. Testing with histamine revealed differences in wheal size and reproducibility among the three devices and testing with saline revealed differing likelihood of inducing a significantly sized wheal. PMID:24433598

Nelson, Harold S; Lopez, Phillip; Curran-Everett, Douglas

2014-01-01

256

Non-invasive prenatal testing for single gene disorders: exploring the ethics  

PubMed Central

Non-invasive prenatal testing for single gene disorders is now clearly on the horizon. This new technology offers obvious clinical benefits such as safe testing early in pregnancy. Before widespread implementation, it is important to consider the possible ethical implications. Four hypothetical scenarios are presented that highlight how ethical ideals of respect for autonomy, privacy and fairness may come into play when offering non-invasive prenatal testing for single gene disorders. The first scenario illustrates the moral case for using these tests for ‘information only', identifying a potential conflict between larger numbers of women seeking the benefits of the test and the wider social impact of funding tests that do not offer immediate clinical benefit. The second scenario shows how the simplicity and safety of non-invasive prenatal testing could lead to more autonomous decision-making and, conversely, how this could also lead to increased pressure on women to take up testing. In the third scenario we show how, unless strong safeguards are put in place, offering non-invasive prenatal testing could be subject to routinisation with informed consent undermined and that woman who are newly diagnosed as carriers may be particularly vulnerable. The final scenario introduces the possibility of a conflict of the moral rights of a woman and her partner through testing for single gene disorders. This analysis informs our understanding of the potential impacts of non-invasive prenatal testing for single gene disorders on clinical practice and has implications for future policy and guidelines for prenatal care.

Deans, Zuzana; Hill, Melissa; Chitty, Lyn S; Lewis, Celine

2013-01-01

257

COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems. Volume 3, Programmer`s guide  

SciTech Connect

The COMMIX-LAR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-lA to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a keg model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The internal aspects of the COMMIX-LAR/P program are presented, covering descriptions of subprograms, variables, and files.

Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

1992-09-01

258

COMMIX-1AR/P: A three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems. Volume 2, User`s guide  

SciTech Connect

The COMMIX-1AR/P computer program is designed for analyzing the steady-state and transient aspects of single-phase fluid flow and heat transfer in three spatial dimensions. This version is an extension of the modeling in COMMIX-1A to include multiple fluids in physically separate regions of the computational domain, modeling descriptions for pumps, radiation heat transfer between surfaces of the solids which are embedded in or surround the fluid, a k-{var_epsilon} model for fluid turbulence, and improved numerical techniques. The porous-medium formulation in COMMIX allows the program to be applied to a wide range of problems involving both simple and complex geometrical arrangements. The input preparation and execution procedures are presented for the COMMIX-1AR/P program and several postprocessor programs which produce graphical displays of the calculated results.

Garner, P.L.; Blomquist, R.N.; Gelbard, E.M.

1992-09-01

259

Compendium of Recent Test Results of Single Event Effects Conducted by the Jet Propulsion Laboratory  

NASA Technical Reports Server (NTRS)

This paper reports heavy ion, proton, and laser induced single event effects results for a variety of microelectronic devices targeted for possible use in NASA spacecrafts. The compendium covers devices tested within the years of 2010 through 2012.

Allen, Gregory R.; Guertin, Steven M.; Scheick, Leif Z.; Irom, Farokh; Zajac, Stephanie

2012-01-01

260

Test and Evaluation of the Cravens Wanlass Modification for Selected Single Phase Fractional Horsepower Motors.  

National Technical Information Service (NTIS)

Tests are reported of four single phase, fractional horsepower motors before and after modification in accordance with principles established by the Cravens Wanlass Corporation to effect improvements in energy efficiency. It compares motor characteristics...

T. D. Cooper

1978-01-01

261

Comparison of intracellular pH transients in single ventricular myocytes and isolated ventricular muscle of guinea-pig.  

PubMed Central

1. Intracellular pH was recorded (double-barrelled pH-selective microelectrodes) in single ventricular myocytes and whole papillary muscles isolated from guinea-pig heart. Both preparations were acid-loaded by various manoeuvres (addition and removal of external NH4Cl or CO2) in order that a comparison could be made of the size and speed of intracellular pH changes and hence of the apparent intracellular buffering power (beta). 2. For the same acid-loading procedure, the size of intracellular pH (pHi) changes was about threefold larger in the isolated myocyte than in whole papillary muscle. The rate of initial acid loading as well as the subsequent rate of pHi recovery (caused by acid extrusion from the cell) were also threefold faster in the myocyte. Estimates of apparent intrinsic (non-CO2) buffering power, based upon the size of pHi changes during acid loading, were 15-20 mmol l-1 for the myocyte and about 70 mmol l-1 for whole muscle. This latter value is similar to previous estimates of beta in heart. 3. When acid extrusion was reduced by applying a high dose of amiloride (1 mmol l-1), then the size of the pHi change during acid loading increased greatly in papillary muscle but changed much less in the myocyte; beta now appeared to be about 30 mmol l-1 in whole muscle but remained essentially unchanged in the myocyte. 4. We conclude that previous values for beta in cardiac muscle have been greatly overestimated because of the presence of sarcolemmal acid extrusion. Paradoxically, this error in estimating beta is far less evident in the isolated myocyte. We suggest that this is because a much more rapid acid loading is achievable in the myocyte so that acid loading will be blunted less by acid extrusion than in whole muscle. We present a simple mathematical model that demonstrates this phenomenon. We conclude that beta in ventricular muscle is likely to resemble that measured in the isolated myocyte, i.e. 15-20 mmol l-1. 5. Slow acid loading in whole ventricular muscle will also affect the kinetics of pHi changes. The model indicates that the rate of pHi recovery from an acid load in papillary muscle does not reflect the pHi dependence of acid extrusion. Instead, it is heavily influenced by the slow rate of acid loading. This emphasises that great care should be taken when interpreting the kinetics of pHi changes in multicellular ventricular preparations.

Bountra, C; Powell, T; Vaughan-Jones, R D

1990-01-01

262

First high power pulsed tests of a dressed 325 MHz superconducting single spoke resonator at Fermilab  

SciTech Connect

In the recently commissioned superconducting RF cavity test facility at Fermilab (SCTF), a 325 MHz, {beta} = 0.22 superconducting single-spoke resonator (SSR1) has been tested for the first time with its input power coupler. Previously, this cavity had been tested CW with a low power, high Q{sub ext} test coupler; first as a bare cavity in the Fermilab Vertical Test Stand and then fully dressed in the SCTF. For the tests described here, the design input coupler with Q{sub ext} {approx} 10{sup 6} was used. Pulsed power was provided by a Toshiba E3740A 2.5 MW klystron.

Madrak, R.; Branlard, J.; Chase, B.; Darve, C.; Joireman, P.; Khabiboulline, T.; Mukherjee, A.; Nicol, T.; Peoples-Evans, E.; Peterson, D.; Pischalnikov, Y.; /Fermilab

2011-03-01

263

Mine electrical power systems. Transients protection, reliability investigation, and safety testing of mine electrical power systems. Volume I--transients in mine electrical power systems. Open file report (final) 24 Jun 74-15 Aug 78  

Microsoft Academic Search

This report contains results of two major efforts related to electrical transients on mine electrical power systems. The first area concerns the use of digital computers to model mine electrical power systems and predict transients or duplicate field recordings of transients. Two existing general purpose circuit analysis programs were used. The first was the TRW Engineering System Simulator or TESS.

Stanek

1979-01-01

264

The Development and Validation of a Formula for Measuring Single-Sentence Test Item Readability.  

ERIC Educational Resources Information Center

A study was conducted with 782 elementary school students to determine whether the Homan-Hewitt Readability Formula could identify the readability of a single-sentence test item. Results indicate that a relationship exists between students' reading grade levels and responses to test items written at higher readability levels. (SLD)

Homan, Susan; And Others

1994-01-01

265

Analytical solutions for efficient interpretation of single-well push-pull tracer tests  

EPA Science Inventory

Single-well push-pull tracer tests have been used to characterize the extent, fate, and transport of subsurface contamination. Analytical solutions provide one alternative for interpreting test results. In this work, an exact analytical solution to two-dimensional equations descr...

266

DESIGN AND PERFORMANCE OF SINGLE-WELL TRACER TESTS AT THE MOBILE SITE  

EPA Science Inventory

Tracer tests are the most reliable field methods for obtaining information describing advection and dispersion in aquifers. The paper describes the design and performance of single-well tracer tests utilizing multilevel observation wells at a field site near Mobile, Alabama. In a...

267

Optical resetting in large drainage basins: tests of zeroing assumptions using single-aliquot procedures  

Microsoft Academic Search

Optical resetting of previously accumulated charge populations at the time of transportation and burial of sediments remains a critical assumption in luminescence dating. This is particularly the case for fluvial sediments. We have tested the extent of bleaching in fluvial environments by applying the single-aliquot regeneration (SAR) equivalent dose (DE) determination technique coupled with tests for partial bleaching. In the

S. Stokes; H. E Bray; M. D Blum

2001-01-01

268

A single radial immunodiffusion test for antibodies to newcastle disease virus  

Microsoft Academic Search

A single radial immunodiffusion (SRD) test for the measurement of antibodies to Newcastle disease virus (NDV) is described. The test involved incorporation of concentrated intact NDV into a gel of agarose with low setting temperature and measurement of opalescent zones produced by the diffusion of antibodies to the NDV surface antigens from wells cut in the gels. With both fowl

H. P. Chu; G. Snell; D. J. Alexander; G. C. Schild

1982-01-01

269

Transient Receptor Potential Channel Polymorphisms Are Associated with the Somatosensory Function in Neuropathic Pain Patients  

PubMed Central

Transient receptor potential channels are important mediators of thermal and mechanical stimuli and play an important role in neuropathic pain. The contribution of hereditary variants in the genes of transient receptor potential channels to neuropathic pain is unknown. We investigated the frequency of transient receptor potential ankyrin 1, transient receptor potential melastin 8 and transient receptor potential vanilloid 1 single nucleotide polymorphisms and their impact on somatosensory abnormalities in neuropathic pain patients. Within the German Research Network on Neuropathic Pain (Deutscher Forscbungsverbund Neuropathischer Schmerz) 371 neuropathic pain patients were phenotypically characterized using standardized quantitative sensory testing. Pyrosequencing was employed to determine a total of eleven single nucleotide polymorphisms in transient receptor potential channel genes of the neuropathic pain patients and a cohort of 253 German healthy volunteers. Associations of quantitative sensory testing parameters and single nucleotide polymorphisms between and within groups and subgroups, based on sensory phenotypes, were analyzed. Single nucleotide polymorphisms frequencies did not differ between both the cohorts. However, in neuropathic pain patients transient receptor potential ankyrin 1 710G>A (rs920829, E179K) was associated with the presence of paradoxical heat sensation (p?=?0.03), and transient receptor potential vanilloid 1 1911A>G (rs8065080, I585V) with cold hypoalgesia (p?=?0.0035). Two main subgroups characterized by preserved (1) and impaired (2) sensory function were identified. In subgroup 1 transient receptor potential vanilloid 1 1911A>G led to significantly less heat hyperalgesia, pinprick hyperalgesia and mechanical hypaesthesia (p?=?0.006, p?=?0.005 and p<0.001) and transient receptor potential vanilloid 1 1103C>G (rs222747, M315I) to cold hypaesthesia (p?=?0.002), but there was absence of associations in subgroup 2. In this study we found no evidence that genetic variants of transient receptor potential channels are involved in the expression of neuropathic pain, but transient receptor potential channel polymorphisms contributed significantly to the somatosensory abnormalities of neuropathic pain patients.

Baron, Ralf; Maier, Christoph; Tolle, Thomas R.; Treede, Rolf-Detlef; Berthele, Achim; Faltraco, Frank; Flor, Herta; Gierthmuhlen, Janne; Haenisch, Sierk; Huge, Volker; Magerl, Walter; Maihofner, Christian; Richter, Helmut; Rolke, Roman; Scherens, Andrea; Uceyler, Nurcan; Ufer, Mike; Wasner, Gunnar; Zhu, Jihong; Cascorbi, Ingolf

2011-01-01

270

Comparison of transient-heating burst test results of unirradiated and irradiated Zircaloy4 fuel rod cladding  

Microsoft Academic Search

The Nuclear Regulatory Commission supported an experimental program to study the mechanical properties of both unirradiated and irradiated fuel rod cladding. The program was designed to produce a mechanical property data base for use in developing modeling codes which could then be used to predict the performance of Zircaloy-4 clad fuel rods under various reactor loss-of-coolant accident (LOCA) conditions. Transient-heating

L. M. Lowry; J. S. Perrin

1982-01-01

271

A Nuclear Interaction Model for Understanding Results of Single Event Testing with High Energy Protons  

NASA Technical Reports Server (NTRS)

An internuclear cascade and evaporation model has been adapted to estimate the LET spectrum generated during testing with 200 MeV protons. The model-generated heavy ion LET spectrum is compared to the heavy ion LET spectrum seen on orbit. This comparison is the basis for predicting single event failure rates from heavy ions using results from a single proton test. Of equal importance, this spectra comparison also establishes an estimate of the risk of encountering a failure mode on orbit that was not detected during proton testing. Verification of the general results of the model is presented based on experiments, individual part test results, and flight data. Acceptance of this model and its estimate of remaining risk opens the hardware verification philosophy to the consideration of radiation testing with high energy protons at the board and box level instead of the more standard method of individual part testing with low energy heavy ions.

Culpepper, William X.; ONeill, Pat; Nicholson, Leonard L.

2000-01-01

272

Understanding the effect of single-fracture heterogeneity from single-well injection-withdrawal (SWIW) tests  

NASA Astrophysics Data System (ADS)

The single-well injection-withdrawal (SWIW) tracer test is a method used to estimate the tracer retardation properties of a fracture or fracture zone. The effects of single-fracture aperture heterogeneity on SWIW-test tracer breakthrough curves are examined by numerical modelling. The effects of the matrix diffusion and sorption are accounted for by using a particle tracking method through the addition of a time delay added to the advective transport time. For a given diffusion and sorption property ( P m) value and for a heterogeneous fracture, the peak concentration is larger compared to a homogeneous fracture. The cumulative breakthrough curve for a heterogeneous fracture is similar to that for a homogeneous fracture and a less sorptive/diffusive tracer. It is demonstrated that the fracture area that meets the flowing water, the specific flow-wetted surface (sFWS) of the fracture, can be determined by matching the observed breakthrough curve for a heterogeneous fracture to that for a homogeneous fracture with an equivalent property parameter. SWIW tests are also simulated with a regional pressure gradient present. The results point to the possibility of distinguishing the effect of the regional pressure gradient from that of diffusion through the use of multiple tracers with different P m values.

Larsson, Martin; Doughty, Christine; Tsang, Chin-Fu; Niemi, Auli

2013-12-01

273

Small-Sample Equating Using a Single-Group Nearly Equivalent Test (SiGNET) Design  

ERIC Educational Resources Information Center

A single-group (SG) equating with nearly equivalent test forms (SiGNET) design was developed by Grant to equate small-volume tests. Under this design, the scored items for the operational form are divided into testlets or mini tests. An additional testlet is created but not scored for the first form. If the scored testlets are testlets 1-6 and the…

Puhan, Gautam; Moses, Timothy P.; Grant, Mary C.; McHale, Frederick

2009-01-01

274

Neutron logging measurements in the single heater test first quarter, FY98  

SciTech Connect

The purpose of the Single Heater Test (SHT), the design of the test, and the borehole layout were reported by OCRWM M&O (1996a). Briefly, the main purpose of the SHT is to study the thermal- mechanical behavior of the densely welded non-lithophysal Topopah Spring tuff at the Exploratory Studies Facility (ESF). The SHT is also used as a shake-down for the test of the coupled thermal- mechanical- hydrological-chemical (TMHC) processes.

Lin, W., LLNL

1998-01-16

275

Space Power Facility-Capabilities for Space Environmental Testing Within a Single Facility  

NASA Technical Reports Server (NTRS)

The purpose of this paper is to describe the current and near-term environmental test capabilities of the NASA Glenn Research Center's Space Power Facility (SPF) located at Sandusky, Ohio. The paper will present current and near-term capabilities for conducting electromagnetic interference and compatibility testing, base-shake sinusoidal vibration testing, reverberant acoustic testing, and thermal-vacuum testing. The paper will also present modes of transportation, handling, ambient environments, and operations within the facility to conduct those tests. The SPF is in the midst of completing and activating new or refurbished capabilities which, when completed, will provide the ability to conduct most or all required full-scale end-assembly space simulation tests at a single test location. It is envisioned that the capabilities will allow a customer to perform a wide range of space simulation tests in one facility at reasonable cost.

Sorge, Richard N.

2013-01-01

276

RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: SINGLE CELL TESTS  

SciTech Connect

An experimental investigation on the performance and durability of single solid oxide electrolysis cells (SOECs) is under way at the Idaho National Laboratory. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOECs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus has been developed for single cell and small stack tests from different vendors. Single cells from Ceramatec Inc. show improved durability compared to our previous stack tests. Single cells from Materials and Systems Research Inc. (MSRI) demonstrate low degradation both in fuel cell and electrolysis modes. Single cells from Saint Gobain Advanced Materials (St. Gobain) show stable performance in fuel cell mode, but rapid degradation in the electrolysis mode. Electrolyte-electrode delamination is found to have significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the microstructure help to mitigate degradation. Polarization scans and AC impedance measurements are performed during the tests to characterize the cell performance and degradation.

X. Zhang; J. E. O'Brien; R. C. O'Brien

2012-07-01

277

Simulation of reactivity transients in current MTRs  

Microsoft Academic Search

This work aims at simulation of reactivity induced transients in High Enriched Uranium (HEU) and Low Enriched Uranium (LEU) cores of a typical Material Test research Reactor (MTR) using PARET code. The transient problem was forced through specification of externally inserted reactivity as a function of time. Reactivity insertions are idealized by ramps and steps. Superdelayed-critical transients, superprompt-critical transients and

Anwar M. Mirza; Salma Khanam; Nasir M. Mirza

1998-01-01

278

Advanced sluicing system test report for single shell tank waste retrieval integrated testing  

SciTech Connect

This document describes the testing performed by ARD Environmental, Inc., and Los Alamos Technical Associates of the LATA/ARD Advanced Sluicing System, in support of ACTR Phase 1 activities. Testing was to measure the impact force and pressures of sluicing streams at three different distances, as measured by the Government supplied load cell. Simulated sluicing of large simulated salt cake and hard pan waste coupons was also performed. Due to operational difficulties experienced with the Government supplied load cell, no meaningful results with respect to sluice stream impact pressure distribution or stream coherence were obtained. Sluice testing using 3000 psi salt cake simulants measured waste retrieval rates of approximately 12 Ml/day (17.6 ft{sup 3}/hr). Rates as high as 314 m{sup 3}/day (463 ft{sup 3}/hr) were measured against the lower strength salt cake simulants.

Berglin, E.J.

1997-05-29

279

Comparative performance of four single extreme outlier discordancy tests from Monte Carlo simulations.  

PubMed

Using highly precise and accurate Monte Carlo simulations of 20,000,000 replications and 102 independent simulation experiments with extremely low simulation errors and total uncertainties, we evaluated the performance of four single outlier discordancy tests (Grubbs test N2, Dixon test N8, skewness test N14, and kurtosis test N15) for normal samples of sizes 5 to 20. Statistical contaminations of a single observation resulting from parameters called ? from ±0.1 up to ±20 for modeling the slippage of central tendency or ? from ±1.1 up to ±200 for slippage of dispersion, as well as no contamination (? = 0 and ? = ±1), were simulated. Because of the use of precise and accurate random and normally distributed simulated data, very large replications, and a large number of independent experiments, this paper presents a novel approach for precise and accurate estimations of power functions of four popular discordancy tests and, therefore, should not be considered as a simple simulation exercise unrelated to probability and statistics. From both criteria of the Power of Test proposed by Hayes and Kinsella and the Test Performance Criterion of Barnett and Lewis, Dixon test N8 performs less well than the other three tests. The overall performance of these four tests could be summarized as N2?N15 > N14 > N8. PMID:24737992

Verma, Surendra P; Díaz-González, Lorena; Rosales-Rivera, Mauricio; Quiroz-Ruiz, Alfredo

2014-01-01

280

Crash tests of three identical low-wing single-engine airplane  

NASA Technical Reports Server (NTRS)

Three identical four place, low wing single engine airplane specimens with nominal masses of 1043 kg were crash tested under controlled free flight conditions. The tests were conducted at the same nominal velocity of 25 m/sec along the flight path. Two airplanes were crashed on a concrete surface (at 10 and 30 deg pitch angles), and one was crashed on soil (at a -30 deg pitch angle). The three tests revealed that the specimen in the -30 deg test on soil sustained massive structural damage in the engine compartment and fire wall. Also, the highest longitudinal cabin floor accelerations occurred in this test. Severe damage, but of lesser magnitude, occurred in the -30 deg test on concrete. The highest normal cabin floor accelerations occurred in this test. The least structural damage and lowest accelerations occurred in the 10 deg test on concrete.

Castle, C. B.; Alfaro-Bou, E.

1983-01-01

281

Ambiguity in measuring matrix diffusion with single-well injection/recovery tracer tests  

USGS Publications Warehouse

Single-well injection/recovery tracer tests are considered for use in characterizing and quantifying matrix diffusion in dual-porosity aquifers. Numerical modeling indicates that neither regional drift in homogeneous aquifers, nor heterogeneity in aquifers having no regional drift, nor hydrodynamic dispersion significantly affects these tests. However, when drift is coupled simultaneously with heterogeneity, they can have significant confounding effects on tracer return. This synergistic effect of drift and heterogeneity may help explain irreversible flow and inconsistent results sometimes encountered in previous single-well injection/recovery tracer tests. Numerical results indicate that in a hypothetical single-well injection/recovery tracer test designed to demonstrate and measure dual-porosity characteristics in a fractured dolomite, the simultaneous effects of drift and heterogeneity sometimes yields responses similar to those anticipated in a homogeneous dual-porosity formation. In these cases, tracer recovery could provide a false indication of the occurrence of matrix diffusion. Shortening the shut-in period between injection and recovery periods may make the test less sensitive to drift. Using multiple tracers having different diffusion characteristics, multiple tests having different pumping schedules, and testing the formation at more than one location would decrease the ambiguity in the interpretation of test data.

Lessoff, S. C.; Konikow, L. F.

1997-01-01

282

Application of the transient test technique to measure local heat transfer coefficients associated with augmented airfoil cooling passages  

NASA Astrophysics Data System (ADS)

Assumptions made in the application of a transient technique using active surface coatings for the determination of Nusselt number distributions within augmented passages typical of gas turbine airfoils are examined. An improved data reduction procedure and an alternative method for error analysis are proposed. It is found that for augmented surfaces, the one-dimensional conduction assumption made in the heat transfer solution is not valid for all times. It is also noted that the experimentally obtained quantities cannot be treated as values that are randomly distributed about some true value for all experimentally measured quantities.

Saabas, H. J.; Arora, S. C.; Abdel Messeh, W.

1987-05-01

283

Columbia University flow instability experimental program: Volume 7. Single tube tests, critical heat flux test program  

SciTech Connect

This report deals with critical heat flux (CHF) measurements in vertical down flow of water at low pressures in a round Inconel tube, 96 inches long and 0.62 inch inside diameter. A total of 28 CHF points were obtained. These data were found to correlate linearly with the single variable q, defined as the heat flux required to raise the enthalpy from the inlet value to the saturation value. These results were compared to the published results of Swedish investigators for vertical upflow of water at low pressures in round tubes of similar diameters and various lengths. The parameter q depends on the inlet enthalpy and is a nonlocal variable, thus this correlation is nonlocal unless the coefficients depend upon tube length in a particular prescribed manner. For the low pressure Swedish data, the coefficients are practically independent of length and hence the correlation is nonlocal. In the present investigation only one length was employed, so it is not possible to determine whether the correlation for these data is local or nonlocal, although there is reason to believe that it is local. The same correlation was applied to a large data base (thousands of CHF points) compiled from the published data of a number of groups and found to apply, with reasonable accuracy over a wide range of conditions, yielding sometimes local and sometimes nonlocal correlations. The basic philosophy of data analysis here was not to generate a single correlation which would reproduce all data, but to search for correlations which apply adequately over some range and which might have some mechanistic significance. The tentative conclusion is that at least two mechanisms appear operative, leading to two types of correlations, one local, the other nonlocal.

Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

1992-09-01

284

Single-tier testing with the C6 peptide ELISA kit compared with two-tier testing for Lyme disease.  

PubMed

For the diagnosis of Lyme disease, the 2-tier serologic testing protocol for Lyme disease has a number of shortcomings including low sensitivity in early disease; increased cost, time, and labor; and subjectivity in the interpretation of immunoblots. In this study, the diagnostic accuracy of a single-tier commercial C6 ELISA kit was compared with 2-tier testing. The results showed that the C6 ELISA was significantly more sensitive than 2-tier testing with sensitivities of 66.5% (95% confidence interval [CI] 61.7-71.1) and 35.2% (95% CI 30.6-40.1), respectively (P < 0.001) in 403 sera from patients with erythema migrans. The C6 ELISA had sensitivity statistically comparable to 2-tier testing in sera from Lyme disease patients with early neurologic manifestations (88.6% versus 77.3%, P = 0.13) or arthritis (98.3% versus 95.6%, P = 0.38). The specificities of C6 ELISA and 2-tier testing in over 2200 blood donors, patients with other conditions, and Lyme disease vaccine recipients were found to be 98.9% and 99.5%, respectively (P < 0.05, 95% CI surrounding the 0.6 percentage point difference of 0.04 to 1.15). In conclusion, using a reference standard of 2-tier testing, the C6 ELISA as a single-step serodiagnostic test provided increased sensitivity in early Lyme disease with comparable sensitivity in later manifestations of Lyme disease. The C6 ELISA had slightly decreased specificity. Future studies should evaluate the performance of the C6 ELISA compared with 2-tier testing in routine clinical practice. PMID:23062467

Wormser, Gary P; Schriefer, Martin; Aguero-Rosenfeld, Maria E; Levin, Andrew; Steere, Allen C; Nadelman, Robert B; Nowakowski, John; Marques, Adriana; Johnson, Barbara J B; Dumler, J Stephen

2013-01-01

285

Determination of surface heat flux using a single embedded thermocouple  

NASA Technical Reports Server (NTRS)

An implicit numerical procedure was developed for predicting the transient heat flux to a material using a single embedded thermocouple. The accuracy of the method was demonstrated by comparisons with analytically generated test data.

Williams, S. D.; Curry, D. M.

1976-01-01

286

The contribution of cytotoxicity to DNA-effects in the single cell gel test (comet assay)  

Microsoft Academic Search

We evaluated genotoxic and cytotoxic effects of the three non-mutagenic and non-carcinogenic compounds p-nitrophenol, d-menthol and sodium N-lauroyl sarcosine which have previously been shown to induce DNA double strand breaks (DNA dsb) secondary to induced cytotoxicity. We tested wheter genotoxic effects in the alkaline single cell gel test (comet assay) may be confounded by cytotoxicity-induced DNA dsb. Cell viability was

Andreas Hartmann; Günter Speit

1997-01-01

287

Microscale material testing of single crystalline silicon: process effects on surface morphology and tensile strength  

Microsoft Academic Search

The mechanical properties of single-crystalline silicon are measured by uniaxial tension tests from microscale beam specimens patterned by four different common silicon etchants — KOH, EDP, TMAH and XeF2. SOI wafers are used to prepare test samples, which are 3–5 ?m thick, 20–100 ?m wide, and 6 mm long beam specimens; these are monolithically mounted on a temporary frame. A

Taechung Yi; Lu Li; Chang-Jin Kim

2000-01-01

288

In-flight and ground testing of single event upset sensitivity in static RAMs  

SciTech Connect

This paper presents the results from in-flight measurements of single event upsets (SEU) in static random access memories (SRAM) caused by the atmospheric radiation environment at aircraft altitudes. The memory devices were carried on commercial airlines at high altitude and mainly high latitudes. The SEUs were monitored by a Component Upset Test Equipment (CUTE), designed for this experiment. The in flight results are compared to ground based testing with neutrons from three different sources.

Johansson, K.; Dyreklev, P.; Granbom, B. [Ericsson Saab Avionics AB, Linkoeping (Sweden)] [Ericsson Saab Avionics AB, Linkoeping (Sweden); Calvet, C. [Aerospatiale Space and Defence, Les Mureaux (France)] [Aerospatiale Space and Defence, Les Mureaux (France); Fourtine, S. [Aerospatiale Avions, Toulouse (France)] [Aerospatiale Avions, Toulouse (France); Feuillatre, O. [Dassault Electronique, Saint-Cloud (France)] [Dassault Electronique, Saint-Cloud (France)

1998-06-01

289

LUNAR OUTGASSING, TRANSIENT PHENOMENA, AND THE RETURN TO THE MOON. II. PREDICTIONS AND TESTS FOR OUTGASSING/REGOLITH INTERACTIONS  

SciTech Connect

We follow Paper I with predictions of how gas leaking through the lunar surface could influence the regolith, as might be observed via optical transient lunar phenomena (TLPs) and related effects. We touch on several processes, but concentrate on low and high flow rate extremes, which are perhaps the most likely. We model explosive outgassing for the smallest gas overpressure at the regolith base that releases the regolith plug above it. This disturbance's timescale and affected area are consistent with observed TLPs; we also discuss other effects. For slow flow, escape through the regolith is prolonged by low diffusivity. Water, found recently in deep magma samples, is unique among candidate volatiles, capable of freezing between the regolith base and surface, especially near the lunar poles. For major outgassing sites, we consider the possible accumulation of water ice. Over geological time, ice accumulation can evolve downward through the regolith. Depending on gases additional to water, regolith diffusivity might be suppressed chemically, blocking seepage and forcing the ice zone to expand to larger areas, up to km{sup 2} scales, again, particularly at high latitudes. We propose an empirical path forward, wherein current and forthcoming technologies provide controlled, sensitive probes of outgassing. The optical transient/outgassing connection, addressed via Earth-based remote sensing, suggests imaging and/or spectroscopy, but aspects of lunar outgassing might be more covert, as indicated above. TLPs betray some outgassing, but does outgassing necessarily produce TLPs? We also suggest more intrusive techniques from radar to in situ probes. Understanding lunar volatiles seems promising in terms of resource exploitation for human exploration of the Moon and beyond, and offers interesting scientific goals in its own right. Many of these approaches should be practiced in a pristine lunar atmosphere, before significant confusing signals likely to be produced upon humans returning to the Moon.

Crotts, Arlin P. S.; Hummels, Cameron [Department of Astronomy, Columbia University, Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027 (United States)

2009-12-20

290

The characterization of carbon nanotube infused glass fibers by single filament fragmentation test methods  

NASA Astrophysics Data System (ADS)

Single filament fragmentation tests were completed for individual glass fibers with varying surface treatments and carbon nanostructure infusions. Fiber fragmentation was analyzed by embedding a single filament into a standard tensile interface, which provided shear stress transfer between a conventional epoxy resin system and the constituent filament. Established single filament fragmentation techniques were used to characterize fiber and interface properties. A novel method of comparing fibers is introduced by correlating bundle tow test results to fiber fragmentation critical length data to qualitatively relate fiber performance. Photoelastic birefringent stress fringes were processed at select fiber fragmentation locations to further characterize the fiber-resin, or fiber-carbon nanostructure-resin, interface. Overall, the performance matrix qualitative comparison method, coupled with stress fringe analysis, proved to be an effective means of qualitatively evaluating fiber and processing parameters, and efficiently identifies the most fruitful path forward for optimized fiber development.

Roach, Andrew Michael

291

Thermal Vacuum Accelerated Life Test on a Prototype Teldix Single-Gimballed Momentum Wheel.  

National Technical Information Service (NTIS)

A prototype TELDIX single-gimballed momentum wheel (SGMW) has been tested in vacuum at isothermal temperatures and with various thermal gradients. The mechanism consists of a momentum wheel which is oscillated in one plane through + or - 5 deg angular mot...

K. Parker J. C. Anderson

1979-01-01

292

ANALYSIS AND INTERPRETATION OF SINGLE-WELL TRACER TESTS IN STRATIFIED AQUIFERS  

EPA Science Inventory

The study deals with the definition and measurement of the dispersive properties of aquifers. Knowledge of such dispersive properties are of fundamental importance to the evaluation, analysis, and simulation of contaminant migration in groundwater. In the single-well test describ...

293

Development of a High Temperature Single Impact Rain Erosion Test Capability.  

National Technical Information Service (NTIS)

A single impact rain erosion test capability has been developed to obtain data on fiber loaded Teflon (e.g. Duroid) ablative radome materials at temperatures up to their ablating temperature (approx. 1250 F). This effort was undertaken as a result of the ...

K. N. Letson S. P. Risner

1984-01-01

294

False discovery and false nondiscovery rates in single-step multiple testing procedures  

Microsoft Academic Search

Results on the false discovery rate (FDR) and the false nondiscovery rate (FNR) are developed for single-step multiple testing procedures. In addition to verifying desirable properties of FDR and FNR as measures of error rates, these results extend previously known results, providing further insights, particularly under dependence, into the notions of FDR and FNR and related measures. First, considering fixed

Sanat K. Sarkar

2006-01-01

295

Single Radial Immunodiffusion Test for Detecting Antibodies Against Surface Antigens of Intracellular and Extracellular Vaccinia Virus  

Microsoft Academic Search

SUMMARY Antibodies to surface antigens of intracellular naked vaccinia virus (INV) and in limited studies extracellular enveloped virus (EEV) were determined by single radial immunodiffusion tests (SRDT) with immobilized virions in agarose gels. Antibodies to INV were demonstrable in rabbit hyperimmune sera (one to four visible zones), smallpox convalescent sera and sera from re-vaccinated individuals. A difference in specificity of

V. J. Prakash; E. Norrby; L. Payne

1977-01-01

296

Status report of the single heater test chapter 4 integrated analyses.  

National Technical Information Service (NTIS)

The primary purposes of the Single Heater Test (SHT) are to study the thermal-mechanical responses of the heated block. The SHT is too small and does not have adequate access for a complete study of the coupled thermal-hydrological-chemical processes. The...

W. Lin

1998-01-01

297

A guideline for heavy ion radiation testing for Single Event Upset (SEU)  

NASA Technical Reports Server (NTRS)

A guideline for heavy ion radiation testing for single event upset was prepared to assist new experimenters in preparing and directing tests. How to estimate parts vulnerability and select an irradiation facility is described. A broad brush description of JPL equipment is given, certain necessary pre-test procedures are outlined and the roles and testing guidelines for on-site test personnel are indicated. Detailed descriptions of equipment needed to interface with JPL test crew and equipment are not provided, nor does it meet the more generalized and broader requirements of a MIL-STD document. A detailed equipment description is available upon request, and a MIL-STD document is in the early stages of preparation.

Nichols, D. K.; Price, W. E.; Malone, C.

1984-01-01

298

Distinction between persistent and transient infection in a bovine viral diarrhoea (BVD) control programme: appropriate interpretation of real-time RT-PCR and antigen-ELISA test results.  

PubMed

Control of bovine viral diarrhoea (BVD) in Belgium is currently implemented on a voluntary basis at herd level and mainly relies on detection and culling of persistently infected (PI) animals. The present field study was conducted during the winter of 2010/2011 to assess the performances of diagnostic assays used in the testing scheme for BVD as proposed by the two Belgian regional laboratories. Individual blood samples were collected from 4972 animals, and individual samples from the same herd were pooled (maximum of 30 individual samples per pool) and screened for the presence of Bovine Viral Diarrhoea Virus (BVDV)-specific RNA using a commercial real-time RT-PCR test (ADIAGENE). Individual samples from positive pools were then tested in parallel with the same RT-PCR test and with an antigen-capture ELISA test (IDEXX) to detect viremic animals. This study demonstrated that individual results differed according to the type of assay used (P < 0.001): 140 animals (2.8%) were positive by RT-PCR and 72 (1.4%) by antigen-ELISA. A second blood sample was taken 40 days later from 74 PCR positive animals to detect persistent viremia: 17 (23%) of these were still PCR positive and considered to be PI and the 57 that no longer tested positive were assumed to be transiently infected (TI) animals. All PI animals were positive also by antigen-ELISA at both time points. Among TI animals, 10 (16%) were positive by antigen-ELISA at the first but none at the second sampling. A highly significant difference in cycle threshold (Ct ) values obtained by RT-PCR was observed between PI and TI animals. ROC analysis was performed to establish thresholds to confirm with high probability that an animal is PI, based on the result of RT-PCR test performed on a single individual blood sample. PMID:23009318

Hanon, J-B; Van der Stede, Y; Antonissen, A; Mullender, C; Tignon, M; van den Berg, T; Caij, B

2014-04-01

299

Tank selection for Light Duty Utility Arm (LDUA) system hot testing in a single shell tank  

SciTech Connect

The purpose of this report is to recommend a single shell tank in which to hot test the Light Duty Utility Arm (LDUA) for the Tank Waste Remediation System (TWRS) in Fiscal Year 1996. The LDUA is designed to utilize a 12 inch riser. During hot testing, the LDUA will deploy two end effectors (a High Resolution Stereoscopic Video Camera System and a Still/Stereo Photography System mounted on the end of the arm`s tool interface plate). In addition, three other systems (an Overview Video System, an Overview Stereo Video System, and a Topographic Mapping System) will be independently deployed and tested through 4 inch risers.

Bhatia, P.K.

1995-01-31

300

MULTIMOMENT RADIO TRANSIENT DETECTION  

SciTech Connect

We present a multimoment technique for signal classification and apply it to the detection of fast radio transients in incoherently dedispersed data. Specifically, we define a spectral modulation index in terms of the fractional variation in intensity across a spectrum. A signal whose intensity is distributed evenly across the entire band has a lower modulation index than a spectrum whose intensity is localized in a single channel. We are interested in broadband pulses and use the modulation index to excise narrowband radio frequency interference by applying a modulation index threshold above which candidate events are removed. The technique is tested both with simulations and using data from known sources of radio pulses (RRAT J1928+15 and giant pulses from the Crab pulsar). The method is generalized to coherent dedispersion, image cubes, and astrophysical narrowband signals that are steady in time. We suggest that the modulation index, along with other statistics using higher order moments, should be incorporated into signal detection pipelines to characterize and classify signals.

Spitler, L. G.; Cordes, J. M.; Chatterjee, S. [Astronomy Department and NAIC, Cornell University, Ithaca, NY 14853 (United States); Stone, J., E-mail: lspitler@astro.cornell.edu [Department of Physics and Astronomy, Barnard College, New York, NY 10027 (United States)

2012-04-01

301

42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Silica dust test; non-powered single-use dust respirators...Combination Gas Masks § 84.1145 Silica dust test; non-powered single-use dust respirators... (e) The total amount of unretained test suspension, after drying, in...

2012-10-01

302

Four applications of permutation methods to testing a single-mediator model  

PubMed Central

Four applications of permutation tests to the single-mediator model are described and evaluated in this study. Permutation tests work by rearranging data in many possible ways in order to estimate the sampling distribution for the test statistic. The four applications to mediation evaluated here are the permutation test of ab, the permutation joint significance test, and the noniterative and iterative permutation confidence intervals for ab. A Monte Carlo simulation study was used to compare these four tests with the four best available tests for mediation found in previous research: the joint significance test, the distribution of the product test, and the percentile and bias-corrected bootstrap tests. We compared the different methods on Type I error, power, and confidence interval coverage. The noniterative permutation confidence interval for ab was the best performer among the new methods. It successfully controlled Type I error, had power nearly as good as the most powerful existing methods, and had better coverage than any existing method. The iterative permutation confidence interval for ab had lower power than do some existing methods, but it performed better than any other method in terms of coverage. The permutation confidence interval methods are recommended when estimating a confidence interval is a primary concern. SPSS and SAS macros that estimate these confidence intervals are provided.

MacKinnon, David P.

2012-01-01

303

A single-step immunochromatographic test for the detection of Entamoeba histolytica antigen in stool samples.  

PubMed

A rapid, single step, sensitive and specific immunochromatographic test for the detection of E. histolytica antigens in the stool samples is described. Monoclonal antibody AC55 specific for E. histolytica was used as capture antibody on nitrocellulose sheet. The same antibody was conjugated to colloidal gold to detect the presence of antigen. In this test, multiple steps of washing, incubation, etc. are not required and there is no need for secondary colour development as gold particles produce a typical reddish, purple colour, when they bind to the solid phase at the site of immune reaction. 151 stool samples from patients with suspected amoebiasis were screened by this assay. Sensitivity of the test was found to be 97.6% and specificity 92.6%. 25 polyxenic E. histolytica cultures and other cultures were also tested. The test did not show positive reaction with other intestinal parasites. PMID:8841457

Bhaskar, S; Singh, S; Sharma, M

1996-09-27

304

High-pressure hydrogen testing of single crystal superalloys for advanced rocket engine turbopump turbine blades  

NASA Technical Reports Server (NTRS)

A screening program to determine the effects of high pressure hydrogen on selected candidate materials for advanced single crystal turbine blade applications is examined. The alloys chosen for the investigation are CM SX-2, CM SX-4C, Rene N-4, and PWA1480. Testing is carried out in hydrogen and helium at 34 MPa and room temperature, with both notched and unnotched single crystal specimens. Results show a significant variation in susceptibility to Hydrogen Environment Embrittlement (HEE) among the four alloys and a marked difference in fracture topography between hydrogen and helium environment specimens.

Alter, W. S.; Parr, R. A.; Johnston, M. H.; Strizak, J. P.

1984-01-01

305

Experimental test of theories of the detection mechanism in a nanowire superconducting single photon detector.  

PubMed

We report an experimental test of the photodetection mechanism in a nanowire superconducting single photon detector. Detector tomography allows us to explore the 0.8-8 eV energy range via multiphoton excitations. High accuracy results enable a detailed comparison of the experimental data with theories for the mechanism of photon detection. We show that the temperature dependence of the efficiency of the superconducting single photon detector is determined not by the critical current but by the current associated with vortex unbinding. We find that both quasiparticle diffusion and vortices play a role in the detection event. PMID:24702419

Renema, J J; Gaudio, R; Wang, Q; Zhou, Z; Gaggero, A; Mattioli, F; Leoni, R; Sahin, D; de Dood, M J A; Fiore, A; van Exter, M P

2014-03-21

306

Transient and Steady-State Tests of the Space Power Research Engine with Resistive and Motor Loads.  

National Technical Information Service (NTIS)

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interact...

J. S. Rauch, M. D. Kankam

1995-01-01

307

[Transient myopia].  

PubMed

Although transient myopia is an extremely rare symptom, systemic diseases which can also lead to a life-threatening condition should also be considered in cases of sudden deterioration of vision. Therefore, the initial diagnosis in an ophthalmological clinic or practice plays a decisive role. PMID:21590350

Borkenstein, A F; Hausberger, S; Mayer, C; Faschinger, C

2011-07-01

308

Hardy's paradox tested in the spin-orbit Hilbert space of single photons  

NASA Astrophysics Data System (ADS)

We test experimentally the quantum "paradox" proposed by L. Hardy [Phys. Rev. Lett. 71, 1665 (1993), 10.1103/PhysRevLett.71.1665] by using single photons instead of photon pairs. This is achieved by addressing two compatible degrees of freedom of the same particle, namely, its spin angular momentum, determined by the photon polarization, and its orbital angular momentum, a property related to the optical transverse mode. Because our experiment involves a single particle, we cannot use locality to logically enforce noncontextuality, which must therefore be assumed based only on the observables' compatibility. On the other hand, our single-particle experiment can be implemented more simply and allows larger detection efficiencies than typical two-particle ones, with a potential future advantage in terms of closing the detection loopholes.

Karimi, Ebrahim; Cardano, Filippo; Maffei, Maria; de Lisio, Corrado; Marrucci, Lorenzo; Boyd, Robert W.; Santamato, Enrico

2014-03-01

309

Flow instability testing of annular geometry fuel elements for LOCA and slow ramp transient with upflow of coolant  

SciTech Connect

This report discusses testing performed to provide data for evaluation and benchmarking of computer codes used for predicting the performance of reactor fuel elements of annular geometry with upward flow of coolant.

Smith, A.C. (Westinghouse Savannah River Co., Aiken, SC (United States)); Blake, J.E.; Childerson, M.T.; Ohrn, T.R.; Privette, R.M. (Babcock and Wilcox Co., Alliance, Oh (United States))

1992-01-01

310

Flow instability testing of annular geometry fuel elements for LOCA and slow ramp transient with upflow of coolant  

SciTech Connect

This report discusses testing performed to provide data for evaluation and benchmarking of computer codes used for predicting the performance of reactor fuel elements of annular geometry with upward flow of coolant.

Smith, A.C. [Westinghouse Savannah River Co., Aiken, SC (United States); Blake, J.E.; Childerson, M.T.; Ohrn, T.R.; Privette, R.M. [Babcock and Wilcox Co., Alliance, Oh (United States)

1992-12-31

311

Pollution emissions from single swirl-can combustor modules at parametric test conditions  

NASA Technical Reports Server (NTRS)

Exhaust pollutant emissions were measured from single swirl-can combustor modules operating over a pressure range of 69 to 276 N/sq cm (100 to 400 psia), over a fuel-air ratio range of 0.01 to 0.04, at an inlet air temperature of 733 K (860 F), and at a constant reference velocity of 23.2 m/sec). Many swirl-can module designs were evaluated; the 11 most promising designs exhibited oxides of nitrogen emission levels lower than that from conventional gas-turbine combustors. Although these single module test results are not necessarily indicative of the performance characteristics of a large array of modules, the results are very promixing and offer a number of module designs that should be tested in a full combustor.

Mularz, E. J.; Wear, J. D.; Verbulecz, P. W.

1975-01-01

312

Interpretation of transmissivity estimates from single-well pumping aquifer tests  

USGS Publications Warehouse

Interpretation of single-well tests with the Cooper-Jacob method remains more reasonable than most alternatives. Drawdowns from 628 simulated single-well tests where transmissivity was specified were interpreted with the Cooper-Jacob straight-line method to estimate transmissivity. Error and bias as a function of vertical anisotropy, partial penetration, specific yield, and interpretive technique were investigated for transmissivities that ranged from 10 to 10,000 m2/d. Cooper-Jacob transmissivity estimates in confined aquifers were affected minimally by partial penetration, vertical anisotropy, or analyst. Cooper-Jacob transmissivity estimates of simulated unconfined aquifers averaged twice the known values. Transmissivity estimates of unconfined aquifers were not improved by interpreting results with an unconfined aquifer solution. Judicious interpretation of late-time data consistently improved estimates where transmissivity exceeded 250 m2/d in unconfined aquifers. ?? 2006 National Ground Water Association.

Halford, K. J.; Weight, W. D.; Schreiber, R. P.

2006-01-01

313

Thermal power tests of single cell thermionic fuel elements and systems  

NASA Astrophysics Data System (ADS)

As part of the TOPAZ International Program, the performance of single cell thermionic fuel elements (TFE) was evaluated durng unfueled ground testing of individual TEF's and TOPAZ II space nuclear power systems. Experiments are coordinated between the TFE test rig and the TOPAZ II system tests to correlate TFE performance. The experiments conducted to date include optimum power data, low power operations in the ``station keeping'' mode and high output power performance. In addition, the data from these experiments are currently being evaluated by the U.S. Naval Post-graduate School for computer thermal modeling of the heat transfer characteristics of a thermionic power system (Benke and Venable 1995). This testing is being conducted at the New Mexico Engineering Research Institute (NMERI) by the Air Force Phillips Laboratory (PL) for the Ballistic Missile Defense Organization (BMDO).

Luchau, David W.; Roh, Nick J.; Taylor, James M.; Izhvanov, Oleg; Vybyvanets, Valery I.; Sinkevich, Valery G.

1995-01-01

314

Construction and validation of parentage testing for thoroughbred horses by 53 single nucleotide polymorphisms.  

PubMed

We characterized the SNP 53 JPN System for parentage verification during horse registry. The SNP 53 JPN System was constructed using 53 highly polymorphic single nucleotide polymorphisms (SNPs), which were amplified and genotyped with 2 multiplex assays. The SNP 53 JPN System showed good resolution for 95 unrelated thoroughbreds, and the exclusion probability (PE01) for each SNP ranged from 11.5 to 23.0%, resulting in a total PE01 value of 99.996%. These results indicate that the SNP 53 JPN System is useful for parentage testing of thoroughbreds. Of the 53 SNPs, 8 SNPs could be used to exclude a pseudo parent and sib combination found using the 2006 International Society for Animal Genetics (ISAG) horse comparison test, as efficiently as the parentage testing systems using short tandem repeats (STRs). Thus, we concluded that the SNP 53 JPN System could provide sufficient and reliable information for routine parentage testing of thoroughbred. PMID:20124759

Hirota, Kei-ichi; Kakoi, Hironaga; Gawahara, Hitoshi; Hasegawa, Telhisa; Tozaki, Teruaki

2010-06-01

315

Proton Single Event Effects (SEE) Testing of the Myrinet Crossbar Switch and Network Interface Card  

NASA Technical Reports Server (NTRS)

As part of the Remote Exploration and Experimentation Project (REE), work was performed to do a proton SEE (Single Event Effect) evaluation of the Myricom network protocol system (Myrinet). This testing included the evaluation of the Myrinet crossbar switch and the Network Interface Card (NIC). To this end, two crossbar switch devices and five components in the NIC were exposed to the proton beam at the University of California at Davis Crocker Nuclear Laboratory (CNL).

Howard, James W., Jr.; LaBel, Kenneth A.; Carts, Martin A.; Stattel, Ronald; Irwin, Timothy L.; Day, John H. (Technical Monitor)

2002-01-01

316

A Test Method of a PEFC Single Cell with Reference Electrodes  

Microsoft Academic Search

A test method of a PEFC single cell with reference electrodes for obtaining correct polarization curves is proposed, where the anode polarization curves of H2\\/O2 and H2\\/Air should be approximately equal. Measured anode polarization curves are usually linear to the current density but not ohmic. Leak current between cathode and reference electrode causes voltage shift on the anode polarization curve.

Yasuyuki Tsutsumi; Seiichirou Ono; Mika Eguchi

2008-01-01

317

High performance N204/amine elements: Blowapart. [test, and analysis of single element injectors  

NASA Technical Reports Server (NTRS)

The work is reported which was conducted to define the mechanisms governing blowapart of hypergolic propellant through the design, fabrication, test, and analysis of single element injectors. Data were developed that show the parameters exhibiting a controlling influence over blowapart are the chamber pressure, orifice diameter, and propellant temperature. Mixing, popping (cyclic blowapart), low pressure separation, and high pressure separation were identified as modes of reactive impingement.

Lawver, B. R.

1974-01-01

318

Performance of Statistical Tests for Single-Source Detection Using Random Matrix Theory  

Microsoft Academic Search

This paper introduces aunified frameworkfor the de- tection of a single source with a sensor array in the context where the noise variance and the channel between the source and the sen- sorsareunknownatthereceiver.TheGeneralizedMaximumLike- lihood Test is studied and yields the analysis of the ratio between the maximum eigenvalue of the sampled covariance matrix and its normalized trace.Usingrecent resultsfrom random matrixtheory,

Pascal Bianchi; Mérouane Debbah; Mylène Maïda; Jamal Najim

2011-01-01

319

Fabrication and Testing of a TMMF S2030 Based Micro Fluidic Device for Single Cell Analysis  

Microsoft Academic Search

Current paper describes the fabrication and testing of a Lab-on-a-chip device using TMMF S2030 dry film resist for single cell analysis. The device typically consists of a bigger channel (20 mum deep), 3 smaller channels (2 mum deep) with embedded reservoir in between and a detector towards the downstream.Whole device has been fabricated on a standard glass wafer. Electrode configuration

V. Mokkapati; L. Zhang; R. Hanfoug; J. Mollinger; J. Bastemeijer; A. Bossche

2009-01-01

320

Study of the comminution characteristics of coal by single particle breakage test device  

SciTech Connect

Single-particle breakage tests of South Blackwater and Ensham coal from the Bowen Basin area in Queensland were conducted by a computer-monitored twin-pendulum device to measure the energy utilization pattern of the breakage particles. Three particle sizes (-16.0+13.2mm, -13.2+11.2mm, -11.2+9.5mm) of each coal were tested by a pendulum device at five input energy levels to measure the specific comminution energy. When particles were tested at constant input energy, the variation of comminution energy between the same size broken particles of Ensham coal was minimal, because Ensham coal is a softer and higher friability coal, which absorbs more input energy than harder coal during breakage tests. For different particle sizes, the specific comminution energy increases linearly with the input energy and the fineness of the breakage products increases with the specific comminution energy. The size distribution graphs are curved but approach linearity in the finer region. At a constant input energy, the twin pendulum breakage product results show that the fineness of the products increases with decrease in particle size and South Blackwater coal produced finer products than the Ensham coal. The t-curves are the family of size distribution curves, which can describe the product size distribution of the breakage particles during single-particle breakage tests.

Sahoo, R. [University of Central Queensland, Rockhampton, Qld. (Australia)

2005-09-01

321

Single cell antimicrobial susceptibility testing by confined microchannels and electrokinetic loading  

PubMed Central

Multidrug-resistant pathogens are an emerging global health problem. In addition to the need of developing new antibiotics in the pipeline, the ability to rapidly determine the antibiotic resistance profiles of bacteria represents one of the most crucial steps toward the management of infectious diseases and the prevention of multidrug-resistant pathogens. Here, we report a single cell antimicrobial susceptibility testing (AST) approach for rapid determination of the antibiotic resistance of bacterial pathogens. By confining individual bacteria in gas permeable microchannels with dimensions comparable to a single bacterium, the antibiotic resistance of the bacteria can be monitored in real-time at the single cell level. To facilitate the dynamic loading of the bacteria into the confined microchannels for observation, AC electrokinetics is demonstrated for capturing bacteria to defined locations in high-conductivity AST buffer. The electrokinetic technique achieves a loading efficiency of about 75% with a negligible effect on the bacterial growth rate. To optimize the protocol for single cell AST, the bacterial growth rate of individual bacteria under different antibiotic conditions has been determined systematically. The applicability of single cell AST is demonstrated by the rapid determination of the antimicrobial resistant profiles of uropathogenic clinical isolates in Mueller-Hinton media and in urine. The antibiotic resistance profiles of bacteria can be determined in less than one hour compared to days in standard culture-based AST techniques.

Lu, Yi; Gao, Jian; Zhang, Donna D.; Gau, Vincent; Liao, Joseph C.; Wong, Pak Kin

2014-01-01

322

Single cell antimicrobial susceptibility testing by confined microchannels and electrokinetic loading.  

PubMed

Multidrug-resistant pathogens are an emerging global health problem. In addition to the need of developing new antibiotics in the pipeline, the ability to rapidly determine the antibiotic resistance profiles of bacteria represents one of the most crucial steps toward the management of infectious diseases and the prevention of multidrug-resistant pathogens. Here, we report a single cell antimicrobial susceptibility testing (AST) approach for rapid determination of the antibiotic resistance of bacterial pathogens. By confining individual bacteria in gas permeable microchannels with dimensions comparable to a single bacterium, the antibiotic resistance of the bacteria can be monitored in real-time at the single cell level. To facilitate the dynamic loading of the bacteria into the confined microchannels for observation, AC electrokinetics is demonstrated for capturing bacteria to defined locations in high-conductivity AST buffer. The electrokinetic technique achieves a loading efficiency of about 75% with a negligible effect on the bacterial growth rate. To optimize the protocol for single cell AST, the bacterial growth rate of individual bacteria under different antibiotic conditions has been determined systematically. The applicability of single cell AST is demonstrated by the rapid determination of the antimicrobial resistant profiles of uropathogenic clinical isolates in Mueller-Hinton media and in urine. The antibiotic resistance profiles of bacteria can be determined in less than 1 h compared to days in standard culture-based AST techniques. PMID:23445209

Lu, Yi; Gao, Jian; Zhang, Donna D; Gau, Vincent; Liao, Joseph C; Wong, Pak Kin

2013-04-16

323

Fluid Structure Interaction in a Cold Flow Test and Transient CFD Analysis of Out-of-Round Nozzles  

NASA Technical Reports Server (NTRS)

This viewgraph presentation describes two nozzle fluid flow interactions. They include: 1) Cold flow nozzle tests with fluid-structure interaction at nozzle separated flow; and 2) CFD analysis for nozzle flow and side loads of nozzle extensions with various out-of-round cases.

Ruf, Joseph; Brown, Andrew; McDaniels, David; Wang, Ten-See

2010-01-01

324

A pulsed nanosecond IR laser diode system to automatically test the Single Event Effects in the laboratory  

Microsoft Academic Search

A pulsed nanosecond IR laser diode system to automatically test the Single Event Effects in laboratory is described. The results of Single Event Latchup (SEL) test on two VLSI chips (VA_HDR64, 0.8 and 1.2?m technology) are discussed and compared to those obtained with high-energy heavy ions at GSI (Darmstadt).

B. Alpat; R. Battiston; M. Bizzarri; S. Blasko; D. Caraffini; L. Dimasso; G. Esposito; L. Farnesini; M. Ionica; M. Menichelli; A. Papi; G. Pontetti; V. Postolache

2002-01-01

325

Cardiovascular-reflex testing and single-fiber electromyography in botulism. A longitudinal study.  

PubMed

Four patients with botulism were studied on admission and at different times after intoxication, using a battery of cardiovascular autonomic tests. The results were compared with clinical status and single-fiber electromyographic findings. In the early stage of intoxication, the control of heart-rate and blood-pressure responsivity was markedly impaired, as was the neuromuscular transmission. At follow-up, results of sympathetic tests normalized earlier than those of parasympathetic tests. The recovery of autonomic function was slower than that of neuromuscular transmission in three patients. Monitoring autonomic derangement in botulism adds further information on the course of the disease and may identify patients at risk for cardiac or respiratory arrest. Further clinical investigation can help in determining more precisely the autonomic sites where the toxin acts. PMID:3028344

Vita, G; Girlanda, P; Puglisi, R M; Marabello, L; Messina, C

1987-02-01

326

Single gimbal/strapdown inertial navigation system for use on spin stabilized flight test vehicles  

SciTech Connect

A hybrid strapdown inertial navigation system intended for use on spin stabilized flight test vehicles is described. The configuration of the navigator which is briefly described consists of three floated rate integrating gyros, one of which is used in conjunction with the gimbal with the remaining two operated in a rate gyro mode. Outputs from the two strapdown gyros and three accelerometers are digitized and processed by a high performance computer. The navigation algorithms utilize a direction cosine matrix formulation for the attitude computation implemented in the digital computer. The implementation of this algorithm for the single gimbal configuration is described. An accuracy model and results for a reentry vehicle flight test trajectory are presented. The flight test performance from launch to reentry is presented.

Watts, A.C.; Andreas, R.D.

1980-01-01

327

Single Event Upset Test at the CRYRING Heavy-Ion Accelerator  

NASA Astrophysics Data System (ADS)

The energy and particle intensity domain of the CRYRING heavy-ion accelerator is well suited for studies of Single Event Upset phenomena. This effect occurs when a charged particle hits a working electronic circuit and the charge created alters its state. The radiative environment is one of the major problems for electronic circuits in an orbiting satellite. The situation is similar for future detectors at the new high-energy physics facilities, like the Large Hadron Collider (LHC) at CERN. The increasing use of submicron technology in combination with a lowering of the circuit voltage decreases the critical charge for temporary upsets. In this article the SEU test setup at CRYRING is described, where memories are used for testing digital circuit technologies. For these tests two types of particle extraction is used and two types of scintillator beam monitors (BaF2 and YAP) are described. Temporary, soft errors were recorded in static RAM memory circuits.

Novak, D.; Kerek, A.; Klamra, W.; Norlin, L.-O.; Bagge, L.; Kaellberg, A.; Paal, A.; Rensfelt, K. G.; Molnar, J.

1999-05-01

328

Reliability of Core Exit Thermocouple for Accident Management Action during SBLOCA and Abnormal Transient Tests at ROSA\\/LSTF  

Microsoft Academic Search

Presented are experimental results on the general performances of core exit thermocouples (CETs) to detect core overheat for accident management (AM) action by using the Large-Scale Test Facility (LSTF) of the ROSA Program of the Japan Atomic Energy Agency. The LSTF is a full-height, full-pressure, and 1\\/48-volumetric-scaled model of a 4-loop pressurized water reactor (PWR). This study was motivated by

Mitsuhiro SUZUKI; Hideo NAKAMURA

2010-01-01

329

Characterization of durable nanostructured thin film catalysts tested under transient conditions using analytical aberration-corrected electron microscopy  

Microsoft Academic Search

The stability of Ru0.1Ir0.9 oxidation evolution reaction (OER) catalysts deposited on Pt-coated nanostructured thin films (NSTFs) has been investigated by aberration-corrected electron microscopy. Accelerated stress tests showed that the OER catalysts significantly improved the durability of the Pt under cell reversal conditions. High-resolution images of the end-of-life NSTFs showed significant Ir loss from the whisker surfaces, while no Pt loss

David A Cullen; Karren Leslie More; Kimberly Shawn Reeves; George Vernstrom; Liliana Atanasoska; Gregory Haugen; Radoslav Atanasoski

2011-01-01

330

GPI-anchored single chain Fv - an effective way to capture transiently-exposed neutralization epitopes on HIV1 envelope spike  

Microsoft Academic Search

BACKGROUND: Identification of broad neutralization epitopes in HIV-1 envelope spikes is paramount for HIV-1 vaccine development. A few broad neutralization epitopes identified so far are present on the surface of native HIV-1 envelope spikes whose recognition by antibodies does not depend on conformational changes of the envelope spikes. However, HIV-1 envelope spikes also contain transiently-exposed neutralization epitopes, which are more

Michael Wen; Reetakshi Arora; Huiqiang Wang; Lihong Liu; Jason T Kimata; Paul Zhou

2010-01-01

331

Single Rod Heat Transfer Tests to Study the Effects of Crud Deposition  

SciTech Connect

Researchers have performed many studies to try to understand crud formation on the fuel pin clad surfaces, which has been observed in pressurized water reactors (PWR) as a result of sub-cooled nucleate boiling and precipitation reactions. Crud deposits, may cause an unexpected change in core power distribution known as crud induced power shift (CIPS) or axial offset anomaly (AOA) if boron species accumulate in the deposits. If the crud deposit is thick enough, the potential exists for fuel rod surface dryout. The Westinghouse Advanced Loop Tester (WALT) at the George Westinghouse Science and Technology Center (STC) will be utilized to examine the effects of crud formation on fuel pin clad dryout. This paper describes a single heated rod test facility designed and fabricated by Westinghouse to study the effects of crud deposition at PWR reactor operating conditions. This test loop is a single rod facility with or without grid support structures on the heater rod and can be used for forced convection and sub-cooled boiling tests with and without crud deposition. Sub-cooled boiling experiments at PWR reactor operating conditions are currently being performed at this facility. The single electrical heated rod in this test facility is instrumented with four movable thermocouples to measure the inside wall temperatures at four azimuthal locations within the rod. In addition, there are two fixed thermocouples to measure the inlet and outlet temperatures of the water flowing on the outside of the heated rod such that an overall energy balance (i.e. comparing the heat absorbed by the water coolant to the measured rod electrical power) can be performed on the facility. This paper will present forced convection and boiling heat transfer curves for clean rod surfaces. Comparison with forced convection correlations and sub-cooled boiling correlations are also presented in this paper. (authors)

Wang, G.; Byers, W.A.; Karoutas, Z.E.; Young, M.Y.; Jacko, R.J. [Westinghouse Electric Company LLC. (United States); Hochreiter, L.E. [The Pennsylvania State University, 302 Walker Building, University Park, PA 16802 (United States)

2006-07-01

332

Rapid antibiotic susceptibility testing by tracking single cell growth in a microfluidic agarose channel system.  

PubMed

Sepsis is one of the major causes of death in the US, necessitating rapid treatment with proper antibiotics. Conventional systems for antibiotic susceptibility testing (AST) take far too long (16-24 h) for the timely treatment of sepsis. This is because they rely on measuring optical density, which relates to bacterial growth, to determine the minimal inhibitory concentrations (MICs) of relevant antibiotics. Thus, there is a desperate need for more improved and rapid AST (RAST) systems. The RAST system can also reduce the growing number of clinical problems that are associated with antibiotic resistance caused by methicillin-resistant Staphylococcus aureus, vancomycin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci. In this study, we demonstrate a microfluidic agarose channel (MAC) system that reduces the AST assay time for determining MICs by single bacterial time lapse imaging. The MAC system immobilizes bacteria by using agarose in a microfluidic culture chamber so that single cell growth can be tracked by microscopy. Time lapse images of single bacterial cells under different antibiotic culture conditions were analyzed by image processing to determine MICs. Three standard bacteria from the Clinical and Laboratory Standard Institute (CLSI) were tested with several kinds of antibiotics. MIC values that were well matched with those of the CLSI were obtained within only 3-4 h. We expect that the MAC system can offer rapid diagnosis of sepsis and thus, more efficient and proper medication in the clinical setting. PMID:23172338

Choi, Jungil; Jung, Yong-Gyun; Kim, Jeewoo; Kim, Sungbum; Jung, Yushin; Na, Hunjong; Kwon, Sunghoon

2013-01-21

333

Design, implementation, and testing of a single axis levitation system for the suspension of a platform.  

PubMed

This paper describes the design and implementation of a single axis DC attraction type suspension system, where a platform (vehicle structure) of around 14 kg mass is made to remain suspended at the desired operating gap under a ferromagnetic guide-way. The prototype has four electromagnetic actuators of attraction type and four inductive gap sensors, all located at the corners of the platform. The four actuators are controlled independently through four identical controllers, and the stable levitation of the platform is achieved through the single input and single output (SISO) control of each air-gap. The emphasis of this work is on the design and development of the switched mode power amplifier cum controller unit for the four actuators. The proposed single switch-based power circuit simplifies the overall hardware, and it can be extended to any number of magnet-coils. A cascade lead compensation control scheme utilizing an inner current loop and outer position loop has been designed and implemented for the stabilization of such a highly unstable and strongly nonlinear system. The prototype has been successfully tested, and stable levitation was demonstrated with the desired operating gap. PMID:17350630

Banerjee, Subrata; Prasad, Dinkar; Pal, Jayanta

2007-04-01

334

Tracer tests in a fractured dolomite: 2. Analysis of mass transfer in single-well injection-withdrawal tests  

NASA Astrophysics Data System (ADS)

We investigated multiple-rate diffusion as a possible explanation for observed behavior in a suite of single-well injection-withdrawal (SWIW) tests conducted in a fractured dolomite. We first investigated the ability of a conventional double-porosity model and a multirate diffusion model to explain the data. This revealed that the multirate diffusion hypothesis/model is consistent with available data and is capable of matching all of the recovery curves. Second, we studied the sensitivity of the SWIW recovery curves to the distribution of diffusion rate coefficients and other parameters. We concluded that the SWIW test is very sensitive to the distribution of rate coefficients but is relatively insensitive to other flow and transport parameters such as advective porosity and dispersivity. Third, we examined the significance of the constant double-log late time slopes (-2.1 to -2.8), which are present in several data sets. The observed late time slopes are significantly different than would be predicted by either conventional double-porosity or single-porosity models and are believed to be a distinctive feature of multirate diffusion. Fourth, we found that the estimated distributions of diffusion rate coefficients are very broad, with the distributions spanning a range of up to 3.6 orders of magnitude. Fifth, when both heterogeneity and solute drift are present, late time behavior similar to multirate mass transfer can occur. Although it is clear that multirate diffusion occurs in the Culebra, the number of orders of magnitude of variability may be overestimated because of the combined effects of drift and heterogeneity.

Haggerty, Roy; Fleming, Sean W.; Meigs, Lucy C.; McKenna, Sean A.

2001-05-01

335

Characterization of durable nanostructured thin film catalysts tested under transient conditions using analytical aberration-corrected electron microscopy  

SciTech Connect

The stability of Ru0.1Ir0.9 oxidation evolution reaction (OER) catalysts deposited on Pt-coated nanostructured thin films (NSTFs) has been investigated by aberration-corrected electron microscopy. Accelerated stress tests showed that the OER catalysts significantly improved the durability of the Pt under cell reversal conditions. High-resolution images of the end-of-life NSTFs showed significant Ir loss from the whisker surfaces, while no Pt loss was observed, indicating that the OER catalysts had protected the catalyst coated whisker surfaces from degradation.

Cullen, David A [ORNL; More, Karren Leslie [ORNL; Reeves, Kimberly Shawn [ORNL; Vernstrom, George [3M Industrial Mineral Products; Atanasoska, Liliana [3M Industrial Mineral Products; Haugen, Gregory [3M Industrial Mineral Products; Atanasoski, Radoslav [3M Industrial Mineral Products

2011-01-01

336

Single Trial Analysis of ERP Using Test Technique and Difference Evaluation of Modulated Vibratory Stimuli  

NASA Astrophysics Data System (ADS)

The purpose of this study is to develop the tactile display which consists of a single vibrator by using the modulated vibration. To achieve this purpose, we must evaluate the stimulus difference of the tactile in the modulated vibratory stimuli. In this study, the stimulus difference has been estimated by detecting the P300 wave in the averaged waveform of the ERP. However, it is indispensable to evaluate the stimulus difference efficiently to make the differential limen in the frequency region to express the modulated vibration clear. In this paper, the single trial analysis on the ERP that the significant difference of the EEG before and after the stimulus presentation is evaluated by the test technique is proposed.

Uchida, Masafumi; Nozawa, Akio; Ide, Hideto

337

Typing of 49 autosomal SNPs by single base extension and capillary electrophoresis for forensic genetic testing.  

PubMed

We describe a method for simultaneous amplification of 49 autosomal single nucleotide polymorphisms (SNPs) by multiplex PCR and detection of the SNP alleles by single base extension (SBE) and capillary electrophoresis. All the SNPs may be amplified from only 100 pg of genomic DNA and the length of the amplicons range from 65 to 115 bp. The high sensitivity and the short amplicon sizes make the assay very suitable for typing of degraded DNA samples, and the low mutation rate of SNPs makes the assay very useful for relationship testing. Combined, these advantages make the assay well suited for disaster victim identifications, where the DNA from the victims may be highly degraded and the victims are identified via investigation of their relatives. The assay was validated according to the ISO 17025 standard and used for routine case work in our laboratory. PMID:22139655

Børsting, Claus; Tomas, Carmen; Morling, Niels

2012-01-01

338

A comparison of single-cycle versus multiple-cycle proof testing strategies  

NASA Technical Reports Server (NTRS)

An evaluation of single-cycle and multiple-cycle proof testing (MCPT) strategies for SSME components is described. Data for initial sizes and shapes of actual SSME hardware defects are analyzed statistically. Closed-form estimates of the J-integral for surface flaws are derived with a modified reference stress method. The results of load- and displacement-controlled stable crack growth tests on thin IN-718 plates with deep surface flaws are summarized. A J-resistance curve for the surface-cracked configuration is developed and compared with data from thick compact tension specimens. The potential for further crack growth during large unload/reload cycles is discussed, highlighting conflicting data in the literature. A simple model for ductile crack growth during MCPT based on the J-resistance curve is used to study the potential effects of key variables. The projected changes in the crack size distribution during MCPT depend on the interactions between several key parameters, including the number of proof cycles, the nature of the resistance curve, the initial crack size distribution, the component boundary conditions (load vs. displacement control), and the magnitude of the applied load or displacement. The relative advantages of single-cycle and multiple-cycle proof testing appear to be specific, therefore, to individual component geometry, material, and loading.

Hudak, S. J., Jr.; Mcclung, R. C.; Bartlett, M. L.; Fitzgerald, J. H.; Russell, D. A.

1990-01-01

339

Tidal Volume Single Breath Washout of Two Tracer Gases - A Practical and Promising Lung Function Test  

PubMed Central

Background Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF6) and helium (He) using an ultrasonic flowmeter (USFM). Methods The tracer gas mixture contained 5% SF6 and 26.3% He, had similar total MM as air, and was applied for a single tidal breath in 13 healthy adults. The USFM measured MM, which was then plotted against expired volume. USFM and mass spectrometer signals were compared in six subjects performing three SBW. Repeatability and reproducibility of SBW, i.e., area under the MM curve (AUC), were determined in seven subjects performing three SBW 24 hours apart. Results USFM reliably measured MM during all SBW tests (n?=?60). MM from USFM reflected SF6 and He washout patterns measured by mass spectrometer. USFM signals were highly associated with mass spectrometer signals, e.g., for MM, linear regression r-squared was 0.98. Intra-subject coefficient of variation of AUC was 6.8%, and coefficient of repeatability was 11.8%. Conclusion The USFM accurately measured relative changes in SF6 and He washout. SBW tests were repeatable and reproducible in healthy adults. We have developed a fast, reliable, and straightforward USFM based SBW method, which provides valid information on SF6 and He washout patterns during tidal breathing.

Singer, Florian; Stern, Georgette; Thamrin, Cindy; Fuchs, Oliver; Riedel, Thomas; Gustafsson, Per; Frey, Urs; Latzin, Philipp

2011-01-01

340

Cluster headache: the peripheral chemosensitivity as indicated by the single-breath CO2 test.  

PubMed

A single-breath CO2 test was carried out in cluster headache patients both during bout and remission, and in matched healthy individuals (n = 10 for each group) to assess peripheral chemosensitivity. The test subjects inhaled one tidal breath of 13% CO2 in air. The response was expressed as the maximal increase in inspiratory minute ventilation (Vi) within 20 seconds from the exposure to CO2, divided by the increase in end-tidal PCO2 (PETCO2) (the difference in PCO2 between the test breath and the preceding control breaths): delta Vi/delta PETCO2. Under the initial resting condition, cluster headache patients within the bout showed a slight hyperventilation in that there was a significantly reduced PETCO2 (P < 0.05, Student's paired t-test), and during remission, higher Vi, and a lower PETCO2 (P < 0.05, Wilcoxon signed rank test), in comparison with the controls. There was no statistically significant difference as regards the peripheral chemosensitivity between cluster headache and control groups. These results indicate that cluster headache patients have an intact and properly-functioning carotid body. PMID:8163371

Shen, J M; Schaanning, J; Kruszewski, P; White, L R

1994-02-01

341

Analyses of the micromechanics of stress transfer in single- and multi-fiber pull-out tests  

Microsoft Academic Search

Analyses have been carried out on the micromechanics of elastic stress transfer taking place across the fiber\\/matrix interface in both single- and multi-fiber pull-out tests. A two-cylinder model for the single-fiber pull-out test and a three-cylinder model for the multi-fiber pull-out test were employed in order to study the fiber pull-out problems. The difference in the stress transfer between the

Shao-Yun Fu; Chee-Yoon Yue; Xiao Hu; Yiu-Wing Mai

2000-01-01

342

Performance of Enhanced Liver Fibrosis test and comparison with transient elastography in the identification of liver fibrosis in patients with chronic hepatitis B infection.  

PubMed

Assessment of liver fibrosis is important in determining prognosis, disease progression and need for treatment in patients with chronic hepatitis B (CHB). Limitations to the use of liver biopsy in assessing fibrosis are well recognized, and noninvasive tests are being increasingly evaluated including transient elastography (TE) and serum markers such as the Enhanced Liver Fibrosis (ELF) test. We assessed performance of ELF and TE in detecting liver fibrosis with reference to liver histology in a cohort of patients with CHB (n = 182), and compared the performance of these modalities. Median age was 46 and mean AST 70 IU/L. Cirrhosis was reported in 20% of liver biopsies. Both modalities performed well in assessing fibrosis at all stages. Area under receiver operator characteristic (AUROC) curves for detecting METAVIR fibrosis stages F ? 1, F ? 2, F ? 3 and F4 were 0.77, 0.82, 0.80 and 0.83 for ELF and 0.86, 0.86, 0.90 and 0.95 for TE. TE performed significantly better in the assessment of severe fibrosis (AUROC 0.80 for ELF and 0.90 for TE, P < 0.01) and cirrhosis (0.83 for ELF and 0.95 for TE, P < 0.01). This study demonstrates that ELF has good performance in detection of liver fibrosis in patients with CHB, and when compared, TE performs better in detection of severe fibrosis/cirrhosis. PMID:24750297

Trembling, P M; Lampertico, P; Parkes, J; Tanwar, S; Viganò, M; Facchetti, F; Colombo, M; Rosenberg, W M

2014-06-01

343

Combining an Internal Pilot with an Interim Analysis for Single Degree of Freedom Tests  

PubMed Central

An internal pilot with interim analysis (IPIA) design combines interim power analysis (an internal pilot) with interim data analysis (two stage group sequential). We provide IPIA methods for single df hypotheses within the Gaussian general linear model, including one and two group t tests. The design allows early stopping for efficacy and futility while also re-estimating sample size based on an interim variance estimate. Study planning in small samples requires the exact and computable forms reported here. The formulation gives fast and accurate calculations of power, type I error rate, and expected sample size.

Kairalla, John A.; Muller, Keith E.; Coffey, Christopher S.

2010-01-01

344

Prolonged, but transient, elevation of liver and biliary function tests in a healthy infant affected with breast milk jaundice.  

PubMed

Unconjugated hyperbilirubinaemia is a common finding in newborns. When it is exaggerated, it is usually investigated in order to exclude several diseases, such as newborn's haemolytic diseases, infections or hypothyroidism. Breast milk jaundice is a form of neonatal jaundice related to breast feeding and it is not usually associated with any clinical issue and/or other laboratory abnormalities. We describe a case of breast milk jaundice being associated, unexpectedly, to significant elevation of plasmatic liver and biliary enzymes. Despite the infant's good clinical condition and growth, several investigations were performed and these ruled out metabolic, infectious and autoimmune liver diseases. All liver function tests normalised by 6-7?months of life. We suggest that the finding of hypertransaminasaemia and hyper-?-glutamyl transpeptidase in a benign clinical context (similar to what we described) should be followed for 6-7?months before performing sophisticated and expensive diagnostic investigations which aim at excluding some unlikely and severe diseases in a completely asymptomatic infant. PMID:24872488

Poddighe, Dimitri; Castelli, Lucia; Marseglia, Gian Luigi; Bruni, Paola

2014-01-01

345

Single-Step Test for Unilateral Limb Ability Following Total Knee Arthroplasty  

PubMed Central

STUDY DESIGN Secondary analysis of a cohort enrolled in a prospective, randomized, longitudinal clinical trial. OBJECTIVES The single-step test (SST) was evaluated to assess its intertester reliability, validity as a test of activity limitation, and responsiveness to change for patients after unilateral total knee arthroplasty (TKA). The SST was also examined to determine whether it could differentiate between the surgical and nonsurgical lower limbs of patients after unilateral TKA and between the surgical limbs of patients after TKA and the limbs of healthy controls. BACKGROUND Tests of functional ability for patients recovering from TKA cannot differentiate the contribution of each limb to performance outcome. A test of unilateral limb ability would provide a metric for assessing the surgical lower extremity, without the confounder of the status of the contralateral lower extremity. METHODS Intertester reliability was assessed between clinicians and between a clinician and a switch mat. Patients who underwent unilateral TKA were tested at initial outpatient physical therapy evaluation, at 3 months after TKA, and at 1 year after TKA. RESULTS The assessment of function with the SST was determined to be reliable between testers when using a stopwatch. SST times were significantly correlated with other measures of lower extremity functional performance, providing evidence of its validity in patients after TKA. The SST was responsive to treatment in patients after TKA, with improvements in time for test completion. Performance on the SST also differed between limbs of patients after TKA and when comparing the limbs of healthy controls to those of patients after TKA. CONCLUSION The SST is a reliable measure between testers and a valid and responsive test of activity limitations when assessing unilateral lower extremity impairments in patients after TKA.

MARMON, ADAM RUBIN; MCCLELLAND, JODIE A.; STEVENS-LAPSLEY, JENNIFER; SNYDER-MACKLER, LYNN

2014-01-01

346

Development of an anti-norovirus single-chain Fv for immunochromatographic test kit.  

PubMed

It was developed that an anti-norovirus single-chain Fv (scFv) antibody for immunochromathographic test kit by using the phage displayed technique and biopanning. To obtain the scFv having wide reactivity for several norovirus genotypes, a mixture of recombinant norovirus capsid proteins, including 11 norovirus genotypes, was used for biopanning. Then, one anti-norovirus scFv antibody that recognized both of norovirus genogroups GI and GII was identified. An immunochromatographic test strip was constructed by using the scFv and demonstrated it to detect norovirus in stool samples. The immunochromatographic strip showed similar sensitivity to a commercially available one on which several monoclonal antibodies are included. PMID:23577605

Nakano, Michihiko; Murofushi, Keita; Watabe, Satoshi; Ohta, Toshiya

2013-01-01

347

Tension and compression testing of single-crystalline gamma Ti-55.5 pct Al  

SciTech Connect

High-quality single crystals 6 to 10 mm in diameter of {gamma}-Ti 55.5 pct Al have been grown using the optical float zone furnace technique. These crystals have been oriented and cut into microsample tension and compression specimens with a gage area of 250 x 250 {micro}m and an effective gage length of 300 {micro}m. These specimens have been deformed using a microsample testing machine which applies loads on the order of 50 N and measures strain using an interferometric strain/displacement gage. Stress-strain curves have been obtained for four different orientations and two temperatures and as a function of the sense of the applied load. Of special interest is the availability of tensile data for the resolved shear stress. Preliminary comparison of tension and compression microsample tests indicates that the tension-compression asymmetry is negligible at 500 K.

Zupan, M.; Hemker, K.J. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Mechanical Engineering

1998-01-01

348

Gravitational independence of single-breath washout tests in recumbent dogs  

NASA Technical Reports Server (NTRS)

The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

Tomioka, Shinichi; Kubo, Susumu; Guy, Harold J. B.; Prisk, G. K.

1988-01-01

349

Single subject fMRI test-retest reliability metrics and confounding factors.  

PubMed

While the fMRI test-retest reliability has been mainly investigated from the point of view of group level studies, here we present analyses and results for single-subject test-retest reliability. One important aspect of group level reliability is that not only does it depend on between-session variance (test-retest), but also on between-subject variance. This has partly led to a debate regarding which reliability metric to use and how different sources of noise contribute to between-session variance. Focusing on single subject reliability allows considering between-session only. In this study, we measured test-retest reliability in four behavioural tasks (motor mapping, covert verb generation, overt word repetition, and a landmark identification task) to ensure generalisation of the results and at three levels of data processing (time-series correlation, t value variance, and overlap of thresholded maps) to understand how each step influences the other and how confounding factors influence reliability at each of these steps. The contributions of confounding factors (scanner noise, subject motion, and coregistration) were investigated using multiple regression and relative importance analyses at each step. Finally, to achieve a fuller picture of what constitutes a reliable task, we introduced a bootstrap technique of within- vs. between-subject variance. Our results show that (i) scanner noise and coregistration errors have little contribution to between-session variance (ii) subject motion (especially correlated with the stimuli) can have detrimental effects on reliability (iii) different tasks lead to different reliability results. This suggests that between-session variance in fMRI is mostly caused by the variability of underlying cognitive processes and motion correlated with the stimuli rather than technical limitations of data processing. PMID:23153967

Gorgolewski, Krzysztof J; Storkey, Amos J; Bastin, Mark E; Whittle, Ian; Pernet, Cyril

2013-04-01

350

Summary of Group Development and Testing for Single Shell Tank Closure at Hanford  

SciTech Connect

This report is a summary of the bench-scale and large scale experimental studies performed by Savannah River National Laboratory for CH2M HILL to develop grout design mixes for possible use in producing fill materials as a part of Tank Closure of the Single-Shell Tanks at Hanford. The grout development data provided in this report demonstrates that these design mixes will produce fill materials that are ready for use in Hanford single shell tank closure. The purpose of this report is to assess the ability of the proposed grout specifications to meet the current requirements for successful single shell tank closure which will include the contracting of services for construction and operation of a grout batch plant. The research and field experience gained by SRNL in the closure of Tanks 17F and 20F at the Savannah River Site was leveraged into the grout development efforts for Hanford. It is concluded that the three Hanford grout design mixes provide fill materials that meet the current requirements for successful placement. This conclusion is based on the completion of recommended testing using Hanford area materials by the operators of the grout batch plant. This report summarizes the regulatory drivers and the requirements for grout mixes as tank fill material. It is these requirements for both fresh and cured grout properties that drove the development of the grout formulations for the stabilization, structural and capping layers.

Harbour, John, R.

2005-04-28

351

AGS new fast extraction system and the single bunch extraction test  

SciTech Connect

For the neutrino physics program and for the CBA injection, a new fast extraction system has been implemented to improve the extraction efficiency and the quality of the extracted beam. Central to the new system is a new fast kicker, placed at the H5 straight section, capable of rising between bunches, t/sub r/ < 170 nsec, and staying constant for 2.6 ..mu..sec with flat top ripple less than +-1.5%. So far, the system has been operated for longer than 3000 hours and routinely extracts 10/sup 13/ ppp at 99% efficiency. Experiment 745 on QCD test requires a single AGS bunch of 40 nsec. For this purpose another fast kicker was placed at the E5 straight section and powered by a new pulser to produce a half sinusoidal pulse with both a rise and fall time of 200 nsec. A single AGS bunch was extracted through the slow beam channel at 22 GeV/c leaving the remaining 11 bunches undisturbed which continued to be accelerated to 29.4 GeV/c and extracted by the H5 kicker through the fast beam channel. Because the ring circumference ratio of CBA to the AGS is 4-3/4, some of the injected beam from the AGS has to contain 11 bunches instead of 12; consequently, this single bunch extraction mode will also be used for CBA injection.

Weng, W.T.

1983-01-01

352

Coincident Steam Generator Tube Rupture and Stuck-Open Safety Relief Valve Carryover Tests (MB-2 Steam Generator Transient Response Test Program).  

National Technical Information Service (NTIS)

In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. The test program consiste...

G. C. Gardner K. Garbett M. Y. Young O. J. Mendler R. Garnsey

1987-01-01

353

Evaluation of the Non-Transient Hydrologic Source Term from the CAMBRIC Underground Nuclear Test in Frenchman Flat, Nevada Test Site  

Microsoft Academic Search

Hydrologic Source Term (HST) calculations completed in 1998 at the CAMBRIC underground nuclear test site were LLNL's first attempt to simulate a hydrologic source term at the NTS by linking groundwater flow and transport modeling with geochemical modeling (Tompson et al., 1999). Significant effort was applied to develop a framework that modeled in detail the flow regime and captured all

A B Tompson; R M Maxwell; S F Carle; M Zavarin; G A Pawloski; D E Shumaker

2005-01-01

354

A new thin-wall beam modal testing method based on single point laser continuous plane scanning vibration measurement  

NASA Astrophysics Data System (ADS)

A high precision and fast testing method for pure modal of vibration body by continuous constant speed plane scanning vibration measurement using single point laser doppler vibrometer is proposed. Thin-walled beam as test object, single point laser continuous plane scanning vibration measurement modal testing scheme is proposed. The processing method for the actual vibration signal is investigated, and the calculating method for the upper and lower alternate envelope of vibration displacement signal is proposed. Thin-walled beam as test object, The modal test platform based on single point laser continuous constant speed plane scanning vibration measurement is put up, and the validity of the modal testing method is verified by the modal testing of thin sheet beam.

Wu, Jigang; Qin, Bin; Li, Xuejun; Zhao, Qiancheng

2013-10-01

355

Single element injector cold flow testing for STME swirl coaxial injector element design  

NASA Technical Reports Server (NTRS)

An oxidizer-swirled coaxial element injector is being investigated for application in the Space Transportation Main Engine (STME). Single element cold flow experiments were conducted to provide characterization of the STME injector element for future analysis, design, and optimization. All tests were conducted to quiescent, ambient backpressure conditions. Spray angle, circumferential spray uniformity, dropsize, and dropsize distribution were measured in water-only and water/nitrogen flows. Rupe mixing efficiency was measured using water/sucrose solution flows with a large grid patternator for simple comparative evaluation of mixing. Factorial designs of experiment were used for statistical evaluation of injector geometrical design features and propellant flow conditions on mixing and atomization. Increasing the free swirl angle of the liquid oxidizer had the greatest influence on increasing the mixing efficiency. The addition of gas assistance had the most significant effect on reducing oxidizer droplet size parameters and increasing droplet size distribution. Increasing the oxidizer injection velocity had the greatest influence for reducing oxidizer droplet size parameters and increasing size distribution for non-gas assisted flows. Single element and multi-element subscale hot fire testing are recommended to verify optimized designs before committing to the STME design.

Hulka, J.; Schneider, J. A.

1993-01-01

356

Estimates of genetic parameters for single- and multiple-country test-day models.  

PubMed

Single- and multiple-country random regression models were applied to estimate genetic parameters for first-lactation test-day milk yield of cows from four countries: Australia, Canada, Italy, and New Zealand. Selected countries represented a wide range of production systems and environments. Milk production in Canada and Italy is based mainly on intensive management systems, while Australia and New Zealand are largely based on rotational grazing. Legendre polynomials with five coefficients were used to model genetic and environmental lactation curves. Covariance components of lactation curve coefficients within and across countries, and selected functions of those, were estimated by Bayesian methods with Gibbs sampling, on selected subsets of data. Countries differed in both phenotypic and genetic parameters of lactation curves between d 5 and 305 of lactation. Principal component analysis of single-trait genetic and environmental covariance matrices showed, however, that the pattern of variability in test-day milk yield was very similar between countries. General level of milk production in lactation and persistency components accounted for more than 90% of the total variance. Estimated genetic correlations between countries for total yield in lactation ranged from 0.65 (Italy and New Zealand) to 0.83 (Australia and New Zealand), indicating a possibility of genotype by environment interaction for some pairs of countries. PMID:12487481

Jamrozik, J; Schaeffer, L R; Weigel, K A

2002-11-01

357

Reducing carbonyl emissions from a heavy-duty diesel engine at US transient cycle test by use of paraffinic/biodiesel blends  

NASA Astrophysics Data System (ADS)

Formaldehyde and acetaldehyde are toxic carcinogens so their reductions in diesel-engine emissions are desirable. This study investigated emissions of carbonyl compounds (CBCs) from an HDDE (heavy-duty diesel engine) at US transient cycle test, using five test fuels: premium diesel fuel (D100), P100 (100% palm-biodiesel), P20 (20% palm-biodiesel + 80% premium diesel fuel), PF80P20 (80% paraffinic fuel + 20% palm-biodiesel), and PF95P05 (95% paraffinic fuel + 5% palm-biodiesel). Experimental results indicate that formaldehyde was the major carbonyl in the exhaust, accounting for 70.1-76.2% of total CBC concentrations for all test fuels. In comparison with D100 (172 mg BHP -1 h -1), the reductions of formaldehyde and acetaldehyde emission factor for P100, P20, PF80P20, and PF95P05 were (-16.8%, -61.8%), (-10.0%, -39.0%), (21.3%, 1.10%), and (31.1%, 19.5%), respectively. Using P100 and P20 instead of D100 in the HDDE increased CBC concentrations by 14.5% and 3.28%, respectively, but using PF80P20 and PF95P05 significantly reduced CBC concentrations by 30.3% and 23.7%, respectively. Using P100 and P20 instead of D100 (2867 ton yr -1) in the HDDE increased CBC emissions by 240 and 224 ton yr -1, respectively, but using PF80P20, and PF95P05 instead of D100 in the HDDE decreased CBC emissions by 711 and 899 ton yr -1, respectively. The above results indicate that the wide usage of paraffinic-palmbiodiesel blends as alternative fuels could protect the environment.

Yuan, Chung-Shin; Lin, Yuan-Chung; Tsai, Cheng-Hsien; Wu, Chia-Chieh; Lin, Yu-Sheng

2009-12-01

358

A Compendium of Recent Optocoupler Radiation Test Data  

NASA Technical Reports Server (NTRS)

We present a compendium of optocoupler radiation test data including neutron, proton and heavy ion Displacement Damage (DD), Single Event Transients (SET) and Total Ionizing Dose (TID). Proton data includes ionizing and non-ionizing damage mechanisms.

Label, K. A.; Kniffin, S. D.; Reed, R. A.; Kim, H. S.; Wert, J. L.; Oberg, D. L.; Normand, E.; Johnston, A. H.; Lum, G. K.; Koga, R.; Day, John H. (Technical Monitor)

2000-01-01

359

A numerical comparison with an exact solution for the transient response of a cylinder immersed in a fluid. [computer simulated underwater tests to determine transient response of a submerged cylindrical shell  

NASA Technical Reports Server (NTRS)

The transient response of an elastic cylindrical shell immersed in an acoustic media that is engulfed by a plane wave is determined numerically. The method applies to the USA-STAGS code which utilizes the finite element method for the structural analysis and the doubly asymptotic approximation for the fluid-structure interaction. The calculations are compared to an exact analysis for two separate loading cases: a plane step wave and an exponentially decaying plane wave.

Giltrud, M. E.; Lucas, D. S.

1979-01-01

360

Crash tests of four identical high-wing single-engine airplanes  

NASA Technical Reports Server (NTRS)

Four identical four place, high wing, single engine airplane specimens with nominal masses of 1043 kg were crash tested at the Langley Impact Dynamics Research Facility under controlled free flight conditions. These tests were conducted with nominal velocities of 25 m/sec along the flight path angles, ground contact pitch angles, and roll angles. Three of the airplane specimens were crashed on a concrete surface; one was crashed on soil. Crash tests revealed that on a hard landing, the main landing gear absorbed about twice the energy for which the gear was designed but sprang back, tending to tip the airplane up to its nose. On concrete surfaces, the airplane impacted and remained in the impact attitude. On soil, the airplane flipped over on its back. The crash impact on the nose of the airplane, whether on soil or concrete, caused massive structural crushing of the forward fuselage. The liveable volume was maintained in both the hard landing and the nose down specimens but was not maintained in the roll impact and nose down on soil specimens.

Vaughan, V. L., Jr.; Hayduk, R. J.

1980-01-01

361

A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies  

NASA Technical Reports Server (NTRS)

Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semi-elliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT vs. SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application.

McClung, R. C.; Chell, G. G.; Millwater, H. R.; Russell, D. A.; Orient, G. E.

1996-01-01

362

A Comparison of Single-Cycle Versus Multiple-Cycle Proof Testing Strategies  

NASA Technical Reports Server (NTRS)

Single-cycle and multiple-cycle proof testing (SCPT and MCPT) strategies for reusable aerospace propulsion system components are critically evaluated and compared from a rigorous elastic-plastic fracture mechanics perspective. Earlier MCPT studies are briefly reviewed. New J-integral estimation methods for semielliptical surface cracks and cracks at notches are derived and validated. Engineering methods are developed to characterize crack growth rates during elastic-plastic fatigue crack growth (FCG) and the tear-fatigue interaction near instability. Surface crack growth experiments are conducted with Inconel 718 to characterize tearing resistance, FCG under small-scale yielding and elastic-plastic conditions, and crack growth during simulated MCPT. Fractography and acoustic emission studies provide additional insight. The relative merits of SCPT and MCPT are directly compared using a probabilistic analysis linked with an elastic-plastic crack growth computer code. The conditional probability of failure in service is computed for a population of components that have survived a previous proof test, based on an assumed distribution of initial crack depths. Parameter studies investigate the influence of proof factor, tearing resistance, crack shape, initial crack depth distribution, and notches on the MCPT versus SCPT comparison. The parameter studies provide a rational basis to formulate conclusions about the relative advantages and disadvantages of SCPT and MCPT. Practical engineering guidelines are proposed to help select the optimum proof test protocol in a given application.

McClung, R. C.; Chell, G. G.; Millwater, H. R.; Russell, D. A.; Millwater, H. R.

1999-01-01

363

Crop and Substrate Tests with Single Use Rooting "Pillows" for the VEGGIE Plant Growth Hardware  

NASA Technical Reports Server (NTRS)

VEGGIE is a small plant production chamber built by ORBITEC. This chamber can be collapsed for easy stowage and deployed in orbit. It is designed for gravity independent operation, and provides 0.17 square m of crop growth area with three primary subsystems: an LED light panel, extendable transparent Teflon bellows to enclose the plants, and a wicking reservoir. VEGGIE would provide the capability for astronauts to grow fresh foods for dietary supplementation. Initial planting concepts tested with the VEGGIE included direct seeding or plug placement on the reservoir surface. These options had issues of salt accumulation and eventual toxicity if the reservoir was filled with nutrient solution, and hardware reuse was limited due to sanitation. In response a rooting packet or "pillow" concept was developed: single-use bags of media containing time release fertilizer with a wicking surface contacting the VEGGIE reservoir. Pillows being tested are small electrostatic bags with a Nitex nylon mesh side, each holding 100 mL of dry media. Six pillows fit in one VEGGIE unit; however pillow size could vary depending on crop selected. Seeds can be planted directly in pillows and planted pillows can be hydrated in space as desired. Our goals were to define optimal media and crops for an ISS mission scenario. Plant tests in pillows were performed in a controlled environment chamber set to habitat-relevant conditions, and capillary reservoir analogs were utilized. Media tested within pillows included: a commercial peat-based potting mix, arcillite (calcined clay), perlite: vermiculite, and peat-based: arcillite blends. Testing included 15 types of leafy greens, snow pea, radish, and herbs. Media performance was crop dependent, but generally plants showed the greatest growth in the peat-based: arcillite mixes. Crops with the best performance in pillows were identified, and testing is underway with select leafy greens examining plant and microbial load response to repeated harvest. We plan to use findings from previous flight testing with media to evaluate the effects of capillary flow from the reservoir to pillows in microgravity.

Massa, Gioia; Newsham, Gerard; Caro, Janicce; Stutte, Gary; Morrow, Robert; Wheeler, Raymond

2011-01-01

364

Single and multiple impact ignition of new and aged high explosives in the Steven Impact Test  

NASA Astrophysics Data System (ADS)

Threshold impact velocities for ignition of exothermic reaction were determined for several new and aged HMX-based solid high explosives using three types of projectiles in the Steven Test. Multiple impact threshold velocities were found to be approximately 10% lower in damaged charges that did not react in one or more prior impacts. Projectiles with protrusions that concentrate the friction work in a small volume of explosive reduced the threshold velocities by approximately 30%. Flat projectiles required nearly twice as high velocities for ignition as rounded projectiles. Blast overpressure gauges were used for both pristine and damaged charges to quantitatively measure reaction violence. Reactive flow calculations of single and multiple impacts with various projectiles suggest that the ignition rates double in damaged charges. .

Chidester, S. K.; Tarver, C. M.; Depiero, A. H.; Garza, R. G.

2000-04-01

365

A Test Method of a PEFC Single Cell with Reference Electrodes  

NASA Astrophysics Data System (ADS)

A test method of a PEFC single cell with reference electrodes for obtaining correct polarization curves is proposed, where the anode polarization curves of H2/O2 and H2/Air should be approximately equal. Measured anode polarization curves are usually linear to the current density but not ohmic. Leak current between cathode and reference electrode causes voltage shift on the anode polarization curve. In order to obtain the ohmic anode polarization, the measured anode polarization curve should be moved vertically up to overlap with the base point. Configuration of the electrode edge adjacent to the reference electrode gives a significant effect on the anode and cathode potential. Polarization of a electrode which is 0.5mm nearer to the reference electrode than the other electrode does not include the ohmic loss of the membrane. Polarization of the other electrode includes the ohmic loss of the membrane instead.

Tsutsumi, Yasuyuki; Ono, Seiichirou; Eguchi, Mika

366

Analysis and testing of high entrainment single nozzle jet pumps with variable mixing tubes  

NASA Technical Reports Server (NTRS)

An analytical model was developed to predict the performance characteristics of axisymmetric single-nozzle jet pumps with variable area mixing tubes. The primary flow may be subsonic or supersonic. The computer program uses integral techniques to calculate the velocity profiles and the wall static pressures that result from the mixing of the supersonic primary jet and the subsonic secondary flow. An experimental program was conducted to measure mixing tube wall static pressure variations, velocity profiles, and temperature profiles in a variable area mixing tube with a supersonic primary jet. Static pressure variations were measured at four different secondary flow rates. These test results were used to evaluate the analytical model. The analytical results compared well to the experimental data. Therefore, the analysis is believed to be ready for use to relate jet pump performance characteristics to mixing tube design.

Hickman, K. E.; Hill, P. G.; Gilbert, G. B.

1972-01-01

367

Single-String Integration Test Measurements of the NEXT Ion Engine Plume  

NASA Technical Reports Server (NTRS)

Measurements were made of a 40 cm ion-thruster plume as part of the single-string-integration-test (SSIT) activity of Phase I of the NASA's Evolutionary Xenon Thruster (NEXT) project. The NEXT ion engine incorporates design improvements that extend NSTAR power levels and efficiencies. During SSIT, an engineering model (EM2) 40 cm engine was operated using an advanced xenon propellant system in combination with either a GRC power console or advanced power processing unit. Integral goals of the single-string phase were to characterize engine performance over the full input power range and to detail thruster operation within the specification of the NEXT throttle table. Plume diagnostics measurements of relative Xe(+) and Xe(++) currents were made using near-field and far-field ExB probes. Planar geometry faraday probes were used to obtain beam current density profiles. This paper reports on the characterization of the EM2 plume over a range of SSIT operating conditions, first with the advanced propellant management system teamed with the GRC power console and then with the power-processing unit.

Snyder, Aaron; Kamhawi, Hani; Patterson, Michael; Britton, Melissa

2005-01-01

368

A test-bed for optimizing high-resolution single particle reconstructions.  

PubMed

It is becoming routine for cryoEM single particle reconstructions to result in 3D electron density maps with resolutions of approximately 10A, but maps with resolutions of 5A or better are still celebrated events. The electron microscope has a resolving power to better than 2A, and thus should not be a limiting factor; instead the practical limitations in resolution most likely arise from a combination of specimen preparation methods, data collection parameters, and data analysis procedures. With the aid of a highly automated system for acquiring images, coupled to a relational database to keep track of all processing parameters, we have taken a systematic approach to optimizing parameters affecting the resolution of single particle reconstructions. Using GroEL as a test-bed, we performed a series of 3D reconstructions where we systematically varied the number of particles used in computing the map, the accelerating voltage of the microscope, and the electron dose used to acquire the images. We also investigated methods for excluding unacceptable or "bad" particles from contributing to the final 3D map. Using relatively standard instrumentation (Tecnai F20, 4K x 4K CCD, side entry cold stage) and a completely automated approach, these approaches resulted in a map with a nominal resolution of 5.4A (FSC(0.5)) in which secondary structure is clearly discernable and the handedness of some of the alpha-helices in the GroEL structure can be determined. PMID:18534866

Stagg, Scott M; Lander, Gabriel C; Quispe, Joel; Voss, Neil R; Cheng, Anchi; Bradlow, Henry; Bradlow, Steven; Carragher, Bridget; Potter, Clinton S

2008-07-01

369

Single-well tracer push-pull test sensitivity w. r. to fracture aperture and spacing  

NASA Astrophysics Data System (ADS)

Dealing with a parallel-fracture system of infinite lateral extension, four characteristic regimes of tracer signal sensitivity w. r. to fracture aperture and w. r. to fracture spacing s (whose reciprocal defines fracture density, or the fluid-rock interface area per volume) can be identified during the pull phase of a single-well push-pull test, also depending upon the ratio between push-phase duration Tpush and a characteristic time scale Ts (defined by s2 / D = Ts , with D denoting the tracer's effective diffusion coefficient): early-time regime: tracer signals are sensitive w. r. to fracture aperture, but insensitive w. r. to fracture spacing; sensitivity w. r. to fracture aperture first increases, then decreases with Tpush / Ts (thus there will be an optimum in terms of to Tpush / Ts , at early pull times); mid-time regime: tracer signals are sensitive w. r. to fracture spacing, but insensitive w. r. to fracture aperture; sensitivity w. r. to fracture spacing increases with Tpush / Ts ; late-time regime: with increasing pull duration, tracer signals become increasingly insensitive w. r. to fracture spacing, while regaining sensitivity w. r. to fracture aperture; 'very late'-time regime: sensitivity w. r. to fracture aperture becomes independent upon Tpush / Ts . From these different regimes, some recommendations can be derived regarding the design and dimensioning of dual-tracer single-well push-pull tests for the specific purposes of geothermal reservoir characterization, using conservative solutes and heat as tracers. Acknowledgement: This study is funded by MWK Niedersachsen (Lower-Saxony's Science and Culture Ministry) and by Baker Hughes (Celle) within task unit 'G6' of the Collaborative Research Project 'gebo' (Geothermal Energy and High-Performance Drilling).

Ghergut, I.; Behrens, H.; Karmakar, S.; Sauter, M.

2012-04-01

370

RETRAC: A program for the analysis of materials test reactors  

Microsoft Academic Search

REactor TRansient Analysis Code (RETRAC) is a computer code specially developed for the analysis of materials test reactor (MTR) cores. The RETRAC code uses a set of coupled neutron point-kinetics equations and thermal-hydraulic conservation laws to simulate nuclear reactor core behavior under transient or accident conditions. The reactor core is represented by a single equivalent unit cell composed of three

B. Baggoura; T. Hamidouche; A. Bousbia-Salah

1994-01-01

371

Laser experiments with single atoms as a test of basic physics  

Microsoft Academic Search

Two experiments with single atoms are reviewed. In the first experiment, the interaction of a single Rydberg atom with a single mode of an electromagnetic field was investigated. The quantum collapse and revivals of the atomic inversion predicted by the Jaynes-Cummings model were demonstrated for the first time. In the second experiment, a single atomic ion stored in a radio-frequency

F. Diedrich; Gerhard Rempe; Joachim Krause; M. O. Scully; H. Walther

1988-01-01

372

Single Event Effects Test Results for Advanced Field Programmable Gate Arrays  

NASA Technical Reports Server (NTRS)

Reconfigurable Field Programmable Gate Arrays (FPGAs) from Altera and Actel and an FPGA-based quick-turnApplication Specific Integrated Circuit (ASIC) from Altera were subjected to single-event testing using heavy ions. Both Altera devices (Stratix II and HardCopy II) exhibited a low latchup threshold (below an LET of 3 MeV-cm2/mg) and thus are not recommended for applications in the space radiation environment. The flash-based Actel ProASIC Plus device did not exhibit latchup to an effective LET of 75 MeV-cm2/mg at room temperature. In addition, these tests did not show flash cell charge loss (upset) or retention damage. Upset characterization of the design-level flip-flops yielded an LET threshold below 10 MeV-cm2/mg and a high LET cross section of about lxlO-6 cm2/bit for storing ones and about lxl0-7 cm2/bit for storing zeros . Thus, the ProASIC device may be suitable for critical flight applications with appropriate triple modular redundancy mitigation techniques.

Allen, Gregory R.; Swift, Gary M.

2006-01-01

373

Frequency of coronal transients and solar activity  

Microsoft Academic Search

The High Altitude Observatory's white light coronagraph aboard Skylab observed some 110 coronal transients - rapid changes in appearance of the corona - during its 227 days of operation. The longitudes of the origins of these transients were not distributed uniformly around the solar surface (51 of the 100 events observed in seven solar rotations arose from a single quadrant

E. Hildner; J. T. Gosling; R. M. MacQueen; R. H. Munro; A. I. Poland; C. L. Ross

1976-01-01

374

Transient radio bursts from rotating neutron stars  

Microsoft Academic Search

The radio sky is relatively unexplored for transient signals, although the potential of radio-transient searches is high. This was demonstrated recently by the discovery of a previously unknown type of source, varying on timescales of minutes to hours. Here we report a search for radio sources that vary on much shorter timescales. We found eleven objects characterized by single, dispersed

M. A. McLaughlin; A. G. Lyne; D. R. Lorimer; M. Kramer; A. J. Faulkner; R. N. Manchester; J. M. Cordes; F. Camilo; A. Possenti; I. H. Stairs; G. Hobbs; N. D'Amico; M. Burgay; J. T. O'Brien

2006-01-01

375

Transient Thermometry with Inert Thermometers.  

National Technical Information Service (NTIS)

A thermometer in contact with a test specimen is inert, if its heat capacity is not small compared with the heat capacity of the test specimen. The response of the thermometer to a transient temperature of the specimen can then be described by a transfer ...

J. C. Erdmann J. A. Jahoda

1966-01-01

376

Emerging optocoupler issues with energetic particle-induced transients and permanent radiation degradation  

Microsoft Academic Search

Radiation-induced permanent degradation and single event transient effects for optocouplers are discussed in this paper. These two effects are independent to the first order and will be addressed separately. Displacement damage-induced degradation of optocoupler current transfer ratio is reviewed. New data are presented that show the importance of application specific testing and that generalized quantification of optocoupler CTR degradation can

R. A. Reed; P. W. Marshall; A. H. Johnston; J. L. Barth; C. J. Marshall; K. A. LaBel; M. D'Ordine; H. S. Kim; M. A. Carts

1998-01-01

377

Setting Passing Scores on Passage-Based Tests: A Comparison of Traditional and Single-Passage Bookmark Methods  

ERIC Educational Resources Information Center

In this study, a variation of the bookmark standard setting procedure for passage-based tests is proposed in which separate ordered item booklets are created for the items associated with each passage. This variation is compared to the traditional bookmark procedure for a fifth-grade reading test. The results showed that the single-passage…

Skaggs, Gary; Hein, Serge F.; Awuor, Risper

2007-01-01

378

Test plan for determining breathing rates in single shell tanksusing tracer gases. Revision 1  

SciTech Connect

This test plan specifies the requirements and conditions for the injection of tracer gas (Helium (He)) into single shell tanks to determine breathing rates using periodic sampling. The eight tanks which have been selected at the time this Test Plan was developed are A-101, AX-102, AX-103, BY-105, C-107, U-103 (U-103 is counted twice, once during the winter months and once during the summer), and U-105. Other tanks to be sampled will be assigned by Pacific Northwest National Laboratory (PNNL) at a later date in the study process as resources allow, the document shall be revised as required. The sampling of headspace for each of these tanks shall be performed using available risers or the Standard Hydrogen Monitoring System (SHMS) cabinet as available. The tank farm vapor cognizant engineer shall assign the injection and sample testing point for each tank and document the point in the field work package. SUMMA TMI canisters, equipped in-line with dual particulate air filters and two silica gel sorbent traps will be used to collect the gas samples. The purpose of dual particulate air filters is to ensure no radioactive particulates are transferred to the SUMMA TMI canisters. The silica gel sorbent traps will effectively eliminate any tritiated water vapor that may be present in the sample gas stream. PNNL shall supply the tracer gases injection system and shall perform the analysis on the headspace samples. TWRS Characterization project shall inject the tracer gas and perform the sampling. Refer to Engineering Task Plan HNF-SD-TWR-ETP-002 for a detailed description of the responsibilities for this task.

Andersen, J.A.

1997-06-20

379

Design and Experimental Test Plan for Hybrid Sulfur Single Cell Pressurized Electrolyzer  

SciTech Connect

The Hybrid Sulfur (HyS) process is one of the leading thermochemical cycles being studied as part of the DOE Nuclear Hydrogen Initiative (NHI). SRNL is conducting analyses and research and development for the Department of Energy on the HyS process. A conceptual design report and development plan for the HyS process was issued on April 1, 2005 [Buckner, et. al., 2005] , and a report on atmospheric testing of a sulfur dioxide depolarized electrolyzer (SDE), a major component of the HyS process, was issued on August 1, 2005 [Steimke, 2005]. The purpose of this report is to document work related to the design and experimental test plan for a pressurized SDE. Pressurized operation of the SDE is a key requirement for development of an efficient and cost-effective HyS process. The HyS process, a hybrid thermochemical cycle proposed and investigated in the 1970s and early 1980s by Westinghouse Electric Corporation, is a high priority candidate for NHI due to the potential for high efficiency and its relatively high level of technical maturity. It was demonstrated in laboratory experiments by Westinghouse in 1978. Process improvements and component advancements that build on that work are being pursued. One of the objectives of the current work is to develop the SDE in order to permit the demonstration of a closed-loop laboratory model of the HyS process. The heart of the HyS process for generating hydrogen is a bank of electrolyzers incorporating sulfur dioxide depolarized anodes. SRNL planned, designed, built and operated a facility for testing single cell electrolyzers at ambient temperature and near atmospheric pressure during the spring and summer of 2005. The major contribution of the SRNL work was the establishment of the proof-of-concept for utilizing the proton-exchange-membrane (PEM) cell design for the SDE operation. Since PEM cells are being extensively developed for automotive fuel cell use, they offer significant potential for cost-effective application for the HyS Process. This report discusses the modifications necessary to the existing SRNL sulfur dioxide depolarized electrolyzer test facility to allow testing at up to 80 C and 90 psig. Because of the need for significant additional equipment and the ability to infer performance results to higher pressures, it recommends delaying further modifications to support testing at up to 300 psig (the commercial goal) until other, higher priority technical issues are addressed. These issues include membrane material selection, component designs, catalyst type and loading, etc. The factors and rationale that should be considered in developing and executing a detailed test matrix for pressurized operation are also discussed. In addition, an electrolyzer assembly design has been developed to allow the testing of different Membrane Electrode Assemblies (MEA's) as part of the planned FY06 HyS Development Program to complete selection of component design specifications for the HyS electrolyzer. MEA's are used in PEM cells to allow intimate contact and minimal resistance between the electrodes and the electrolyte layer. The pressurized electrolyzer assembly presented in this report will facilitate rapid change-out and testing of various MEA designs as part of the electrolyzer development effort.

Steeper, T. J.; Steimke, J. L.

2005-09-01

380

Non-invasive methods for the assessment of hepatic fibrosis: transient elastography, hyaluronic acid, 13C-aminopyrine breath test and cytokeratin 18 fragment.  

PubMed

BACKGROUND. In the management of chronic hepatitis C (CHC) patients, liver biopsy is the gold standard for liver fibrosis assessment despite some technical limits and risks. Non-invasive approaches have been proposed as alternative methods to evaluate structural liver damage. AIM. To investigate the diagnostic accuracy of transient elastography, 13C-aminopyrine breath test (13C-ABT), serum hyaluronic acid (HA) and cytokeratin 18 Asp396 fragment (CK-18) as non-invasive methods of liver fibrosis assessment ad their correlation to METAVIR score. MATERIAL AND METHODS. In a cohort of 57 CHC patients, liver stiffness, cumulative percentage of administered dose of 13C-aminopyrine at 120 min, serum HA and serum CK-18 concentration were determined. Diagnostic accuracy in detecting significant fibrosis (F ? 2), severe fibrosis (F ? 3) and cirrhosis (F = 4) was assessed by the area under the receiver operating characteristic curve. RESULTS. Liver fibrosis score showed a strong correlation with liver stiffness (r = 0.667; p < 0.0001) and a significant inverse correlation with 13C-ABT results (r = -0.418; p = 0.0012). A weaker correlation was found with CK18 (r = 0.329; p = 0.0126) and no correlation with HA. Areas under the curve of elastography, 13C-ABT, HA and CK18 were: 0.98, 0.75, 0.69, 0.64, respectively, for F ? 2; 0.97, 0.69, 0.80, 0.66, respectively, for F ? 3; 0.95, 0.64, 0.70, 0.56, respectively, for F = 4. CONCLUSION. Elastography has the best diagnostic accuracy for the assessment of the degree of liver fibrosis in CHC patients. Its application can provide an alternative useful tool for monitoring the disease evolution. PMID:24378271

Caviglia, Gian Paolo; Ciancio, Alessia; Rosso, Chiara; Abate, Maria Lorena; Olivero, Antonella; Pellicano, Rinaldo; Touscoz, Giovanni Antonio; Smedile, Antonina; Rizzetto, Mario

381

Comparison of numerical predictions and experimental measurements for the transient thermal behavior of a board-mounted electronic component  

Microsoft Academic Search

Numerical predictive accuracy is investigated for transient component heat transfer using a computational fluid dynamics (CFD) code dedicated to the thermal analysis of electronic equipment. The test cases are based on a single printed circuit board (PCB)-mounted, 160-lead PQFP component, analyzed in still-air, and both 1 and 2.25 m\\/s forced airflows. Three types of transient operating conditions are considered, namely

ValCrie Eveloy; Peter Rodgers; John Lohan

2002-01-01

382

Application of nano-indentation, nano-scratch and single fibre tests in investigation of interphases in composite materials  

Microsoft Academic Search

Three novel experimental techniques were employed in this work in order to investigate the influence of the interphase region in polymer–glass composites on the bulk material properties: (i) the microdroplet test is a single fibre test designed to characterize the fibre–matrix bond (interface region) and to determine the interfacial shear stress in composite material; (ii) the nano-indentation test, a novel

A Hodzic; S Kalyanasundaram; J. K Kim; A. E Lowe; Z. H Stachurski

2001-01-01

383

Combined Single-Drop and Rotating Drum Dustiness Test of Fine to Nanosize Powders Using a Small Drum  

Microsoft Academic Search

A dustiness test has been developed that performs both a single-drop and a continuous rotation test using a 6-g sample. Tests were completed on pigment-grade and ultrafine TiO2, two grades of corundum (Aloxite), yttrium-stabilized zirconia (Y-zirconia) granules, fumed silica, goethite, talc and bentonite. The generated particles were quantified by counting and sizing at 1-s time resolution using the TSI Fast

THOMAS SCHNEIDER; KELD ALSTRUP JENSEN

2008-01-01

384

Single molecule bridge as a testing ground for using NGF outside of the steady current regime  

NASA Astrophysics Data System (ADS)

The simplest nanoscopic system, a molecular bridge consisting of a molecular island with one or few electronic or vibronic levels coupled to non-interacting leads can be treated using non-equilibrium Green's functions (NGF). We follow the well known procedure of Jauho, Wingreen and Meir (JWM). In the present work, we concentrate on the little investigated transient behavior of the molecular bridge undergoing abrupt changes. The transient process depends on the initial conditions at a finite time which may incorporate initial correlations. As an example, we study the electron response to sudden connecting the molecule to one or both leads. To obtain explicit solutions, we neglect all interactions at the island, whose role is mimicked by the island-leads coupling. We explore this analogy and obtain a complete solution for the transient NGF for arbitrary “initial correlations” represented by off-diagonal coherences between the initial electron state of the island and of the leads. This direct one-electron solution is confronted with the field theoretic approach in the particular case of the switch-on states, for which the initial correlations result from the previous history of the system. This is formally captured by the partitioning-in-time of the NGF, which we combine with the JWM theory. It is the virtue of partitioning method to express the transient NGF in terms of the building blocks of stationary-state NGF with zero, one or both leads connected. The direct and the partitioning solutions are reduced explicitly from one to the other, clarifying thus the meaning of the singular terms of the self-energy for correlated initial conditions.

Velický, B.; Kalvová, A.; Špi?ka, V.

2010-01-01

385

Advanced transient waveform digitizers  

NASA Astrophysics Data System (ADS)

A series of multi-channel transient waveform digitization integrated circuits with up to 5 GHz sample rates and parallel 10-bit digitization has been designed, tested, and fabricated in large quantities. The current CMOS circuit uses four arrays of 128 fast switched capacitors per channel to record four parallel analog transient inputs. Triggering and clocking is provided by a current-mode adjustable asynchronous active delay line that uses look-ahead to generate 128 4-way interleaved clocks without the need for external high-speed clocking. After transient capture, each channel is fed into 128 parallel 10-bit analog to digital converters for fast, channel-parallel digitization, followed by digital readout. The fast triggering and waveform capture, channel-parallel digitization and convenient word-parallel digital readout results in a responsive and low dead-time system. Acquisition sample rates range from ~50 kHz to ~3 GHz. Analog input bandwidth is approximately 350 MHz. Fixed-pattern spatial noise, after on-chip digitization, is equivalent to ~5 mV RMS. Temporal noise is typically equivalent to ~1 mV RMS, for a signal to noise ratio of ~2,500:1, RMS. This integrated circuit, the "Analog Transient Waveform Digitizer," has been successfully used to instrument the AMANDA and KamLAND neutrino physics experiments, and has been selected for use in the IceCube neutrino observatory. Current efforts to improve this technology will yield larger array sizes, sample rates in excess of 10 GHz, analog bandwidth exceeding 1 GHz, higher conversion rates, lower dead-time, greater uniformity and enhanced flexibility and ease of use.

Kleinfelder, Stuart

2003-02-01

386

CHARACTERIZATION TESTING AND ANALYSIS OF SINGLE CELL SO2 DEPOLARIZED ELECTROLYZER  

SciTech Connect

This document reports work performed at the Savannah River National Laboratory (SRNL) that further develops the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. This work was begun at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. Feed to the anode of the electrolyzer is sulfuric acid solutions containing dissolved sulfur dioxide. The partial pressure of sulfur dioxide may be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures may be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell is collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to operate, versatile, and reliable.

Steimke, J; Timothy Steeper, T

2006-09-15

387

Study on a test of optical stochastic cooling scheme in a single pass beam line  

SciTech Connect

A feasibility study of an experiment to test the principle of optical stochastic cooling is presented. We propose to build a new beamline in the extraction area of the ALS Booster synchrotron, where we will include a bypass lattice similar to the lattice that could be used in the cooling insertion in a storage ring. Of course, in the single pass beamline we cannot achieve cooling, but we can test all the functions of the bypass lattice that are required to achieve cooling in a storage ring. As it is stated in, there are stringent requirements on the time-of-flight properties of the bypass lattice employed in a cooling scheme. The pathlengths of particle trajectories in the bypass must be fairly insensitive to the standard set of errors that usually affect the performance of storage rings. Namely, it is necessary to preserve all fluctuations in the longitudinal particle density within the beam from the beginning to the end of the bypass lattice with the accuracy of {lambda}/2{pi}, where A is the carrying (optical) wavelength. According to, cooling will completely vanish if a combined effect of all kinds of errors will produce a spread of the pathlengths of particle trajectories larger than {lambda}/2 and the cooling time will almost double if the spread of the pathlengths is {lambda}/2{pi}. At a first glance, {lambda}/2{pi} {approx_equal} 0.1/{mu}m is such a small value that satisfying this accuracy looks nearly impossible. However, simulations show that a carefully designed bypass can meet all the requirements even with rather conservative tolerance to errors.

Chattopadhyay, S.; Kim, C.; Massoletti, D.; Zholents, A. [and others

1997-01-01

388

Chlamydia trachomatis Test-of-Cure Cannot Be Based on a Single Highly Sensitive Laboratory Test Taken at Least 3 Weeks after Treatment  

PubMed Central

Current test-of-cure practice in patients with Chlamydia trachomatis (Ct) infection is to confirm cure with a single test taken at least 3 weeks after treatment. Effectiveness of single-time-point testing however lacks a scientific evidence basis and the high sensitivity of laboratory assays nowadays in use for this purpose may compromise the clinical significance of their results. Prospectively following 59 treated Ct infections, administering care as usual, the presence of Ct plasmid DNA and rRNA was systematically assessed by multiple time-sequential measurements, i.e. on 18 samples taken per patient during 8 weeks following treatment with a single dose of 1000 mg Azythromycin. A high proportion (42%) of Ct infections tested positive on at least one of the samples taken after 3 weeks. Patients' test results showed substantial inter-individual and intra-individual variation over time and by type of NAAT used. We demonstrated frequent intermittent positive patterns in Ct test results over time, and strongly argue against current test-of-cure practice.

Dukers-Muijrers, Nicole H. T. M.; Morre, Servaas A.; Speksnijder, Arjen; van der Sande, Marianne A. B.; Hoebe, Christian J. P. A.

2012-01-01

389

Initial comparison of single cylinder Stirling engine computer model predictions with test results  

NASA Technical Reports Server (NTRS)

A NASA developed digital computer code for a Stirling engine, modelling the performance of a single cylinder rhombic drive ground performance unit (GPU), is presented and its predictions are compared to test results. The GPU engine incorporates eight regenerator/cooler units and the engine working space is modelled by thirteen control volumes. The model calculates indicated power and efficiency for a given engine speed, mean pressure, heater and expansion space metal temperatures and cooler water inlet temperature and flow rate. Comparison of predicted and observed powers implies that the reference pressure drop calculations underestimate actual pressure drop, possibly due to oil contamination in the regenerator/cooler units, methane contamination in the working gas or the underestimation of mechanical loss. For a working gas of hydrogen, the predicted values of brake power are from 0 to 6% higher than experimental values, and brake efficiency is 6 to 16% higher, while for helium the predicted brake power and efficiency are 2 to 15% higher than the experimental.

Tew, R. C., Jr.; Thieme, L. G.; Miao, D.

1979-01-01

390

Happy eating: the single target implicit association test predicts overeating after positive emotions.  

PubMed

For many years, questionnaires have been considered the standard when examining emotional eating behavior. However, recently, some controversy has arisen about these questionnaires, and their usefulness in identifying emotional eaters has been questioned. The current study aimed to investigate the Single Target Implicit Association Test (ST-IAT) as a measure of emotional eating. Two ST-IATs (assessing food-positive and food-negative associations respectively) and the Dutch Eating Behaviour Questionnaire (DEBQ) were compared in undergraduate students. A positive, negative or neutral mood was induced by means of a film clip, and milkshake consumption was measured during and after the mood induction. It was hypothesized that participants with strong emotion-food associations on the ST-IATs (i.e., IAT-emotional eaters) would consume more food in the emotion induction condition corresponding to that emotion, as compared to those with weak emotion-food associations as well as to those in the neutral condition. Participants who scored high on both the positive and negative ST-IATs ate more during a positive mood induction than during a negative mood induction. This effect did not extend to milkshake consumption after the mood induction procedure. In addition, IAT-positive emotional eaters consumed more food than IAT-non-emotional eaters. No effects of the DEBQ on milkshake consumption were found. It is concluded that the ST-IAT has potential as a measure of emotional eating. PMID:23910779

Bongers, Peggy; Jansen, Anita; Houben, Katrijn; Roefs, Anne

2013-08-01

391

Coaxial HOM Coupler designs tested on a single cell niobium cavity  

SciTech Connect

Coaxial higher order mode (HOM) couplers have been developed for HERA cavities and are used in TESLA, SNS and JLab upgrade cavities. The principle of operation is the rejection of the fundamental mode by the tunable filter of the coupler and the transmission of the HOMs. It has been recognized recently that inappropriate thermal designs of the feedthrough for the pick-up probe of the HOM coupler will not sufficiently carry away the heat generated in the probe tip by the fundamental mode fields, causing a built-up of the heating of the niobium probe tip and subsequently, a deterioration of the cavity quality factor has been observed in CW operation. An improvement of the situation has been realized by a better thermal design of the feedthrough incorporating a sapphire rf window [1]. An alternative is a modification of the coupler loop (?F? ? part) with an extension towards the pick-up probe. This design has been tested on a single cell niobium cavity in comparison to a ''standard TESLA'' configuration by measuring the Eacc behavior at 2 K. The measurements clearly indicate that the modified version of the coupler loop is thermally much more stable than the standard version.

Peter Kneisel; Genfa Wu; Gianluigi Ciovati; Jacek Sekutowicz

2006-08-28

392

Scaling submillimeter single-cycle transients toward megavolts per centimeter field strength via optical rectification in the organic crystal OH1.  

PubMed

We present the generation of high-power single-cycle terahertz (THz) pulses in the organic salt crystal 2-[3-(4-hydroxystyryl)-5.5-dimethylcyclohex-2-enylidene]malononitrile or OH1. Broadband THz radiation with a central frequency of 1.5 THz (?(c)=200 ?m) and high electric field strength of 440 kV/cm is produced by optical rectification driven by the signal of a powerful femtosecond optical parametric amplifier. A 1.5% pump to THz energy conversion efficiency is reported, and pulse energy stability better than 1% RMS is achieved. An approach toward the realization of higher field strength is discussed. PMID:22378431

Ruchert, Clemens; Vicario, Carlo; Hauri, Christoph P

2012-03-01

393

Enhancing the Fibre Matrix Adhesion of Natural Fibre Reinforced Polypropylene by Electron Radiation Analyzed with the Single Fibre Fragmentation Test  

Microsoft Academic Search

The effects of electron radiation on natural fibre reinforced polypropylene have been analyzed with the single fibre fragmentation test. Specimens of single hemp, flax, ramie and cotton fibres\\/fibre bundles embedded in a polypropylene sheet were irradiated with electron radiation of 10 MeV with intensities of 5, 15 and 33 kGy. The radiation led to a strain reduction of the polypropylene

Tim Huber; Udo Biedermann; Jörg Müssig

2010-01-01

394

Interpretation of numerical transport tests with single and dual porous medium approaches  

NASA Astrophysics Data System (ADS)

Preferential flow paths (PFP) in alluvial sediments influence the fate of contaminants in ground water and render the application of the classical Fickian approach doubtful. In order to improve the comprehension of this remark and its practical effects, numerical experiments of conservative solute transport were performed on three blocks of alluvial sediments from the Ticino basin (Northern Italy), described by Zappa et al. (doi:10.1016/j.jhydrol.2005.10.016). The volume of each block is about 6m3 and the conductivity field is assigned on cubic voxels with side equal to 2cm. Flow modelling was conducted with a conservative finite difference scheme and convective transport with particle tracking (Vassena et al., doi:10.1007/s10040-009-0523-2). The numerical experiments simulate the evolution of a tracer plume which is instantaneously injected through the incoming face and travels along a longitudinal average flow bounded by lateral no flow boundaries. The interpretation of the results is conducted by fitting the cumulative breakthrough curve (BTC) obtained from the analytical solution of the 1D convective-dispersive equation to the numerical test data, through the calibration of the Darcy's velocity and the dispersion coefficient. Results for the classical single porous medium (SPM) case show some discrepancies due to the presence of PFP, which could be taken into account if a dual porous medium (DPM) is considered. In particular the domain is modelled as the superposition of two porous media, characterised by high and low conductivity. Most of the DPM models developed earlier neglect the flow rate in the low K porous medium and include a possibly linear mixing between the two media. Here the flow in the low K porous medium is taken into account, but mixing is neglected. The fit between cumulative BTC obtained from numerical test data and analytical solutions was conducted with the Levenberg-Marquardt algorithm, supported by the analysis of the uniqueness of the inverse problem, which is very critical for the DPM approach, since five parameters have to be calibrated (the Darcy's velocities and the dispersion coefficients for both media and the fraction of solute mass travelling in the high K medium). The DPM model permits to improve the fit of the cumulative BTC but it requires the calibration of several parameters. The tests clearly show that the improvement of the results is particularly important for those blocks where PFP are more evident. Furthermore the DPM model often reduces the differences between the temporal moments of the BTC computed from the analytical solution and from the numerical experiment data.

Baratelli, Fulvia; Giudici, Mauro; Vassena, Chiara

2010-05-01

395

Monitoring transient elastic energy storage within the rotary motors of single FoF1-ATP synthase by DCO-ALEX FRET  

NASA Astrophysics Data System (ADS)

The enzyme FoF1-ATP synthase provides the 'chemical energy currency' adenosine triphosphate (ATP) for living cells. Catalysis is driven by mechanochemical coupling of subunit rotation within the enzyme with conformational changes in the three ATP binding sites. Proton translocation through the membrane-bound Fo part of ATP synthase powers a 10-step rotary motion of the ring of c subunits. This rotation is transmitted to the ? and ? subunits of the F1 part. Because ? and ? subunits rotate in 120° steps, we aim to unravel this symmetry mismatch by real time monitoring subunit rotation using single-molecule Förster resonance energy transfer (FRET). One fluorophore is attached specifically to the F1 motor, another one to the Fo motor of the liposome-reconstituted enzyme. Photophysical artifacts due to spectral fluctuations of the single fluorophores are minimized by a previously developed duty cycle-optimized alternating laser excitation scheme (DCO-ALEX). We report the detection of reversible elastic deformations between the rotor parts of Fo and F1 and estimate the maximum angular displacement during the load-free rotation using Monte Carlo simulations.

Ernst, Stefan; Düser, Monika G.; Zarrabi, Nawid; Börsch, Michael

2012-02-01

396

Transient dynamics and the destabilizing effects of prey heterogeneity.  

PubMed

The presence of prey heterogeneity and weakly interacting prey species is frequently viewed as a stabilizer of predator-prey dynamics, countering the destabilizing effects of enrichment and reducing the amplitude of population cycles. However, prior model explorations have largely focused on long-term, dynamic attractors rather than transient dynamics. Recent theoretical work shows that the presence of prey that are defended from predation can have strongly divergent effects on dynamics depending on time scale: prey heterogeneity can counteract the destabilizing effects of enrichment on predator-prey dynamics at long time scales but strongly destabilize systems during transient phases by creating long periods of low predator/prey abundance and increasing extinction probability (an effect that is amplified with increasing enrichment). We tested these general predictions using a planktonic system composed of a zooplankton predator and multiple algal prey. We first parameterized a model of our system to generate predictions and tested these experimentally. Our results qualitatively supported several model predictions. During transient phases, presence of defended algal prey increased predator extinctions at low and high enrichment levels compared to systems with only a single edible prey. This destabilizing effect was moderated at higher dilution rates, as predicted by our model. When examining dynamics beyond initial oscillations, presence of the defended prey increased predator-prey temporal variability at high nutrient enrichment but had no effect at low nutrient levels. Our results highlight the importance of considering transient dynamics when assessing the role of stabilizing factors on the dynamics of food webs. PMID:22624217

Steiner, Christopher F; Klausmeier, Christopher A; Litchman, Elena

2012-03-01

397

Validation of a Pressure-Based Combustion Simulation Tool Using a Single Element Injector Test Problem  

NASA Technical Reports Server (NTRS)

The traditional design and analysis practice for advanced propulsion systems, particularly chemical rocket engines, relies heavily on expensive full-scale prototype development and testing. Over the past decade, use of high-fidelity analysis and design tools such as CFD early in the product development cycle has been identified as one way to alleviate testing costs and to develop these devices better, faster and cheaper. Increased emphasis is being placed on developing and applying CFD models to simulate the flow field environments and performance of advanced propulsion systems. This necessitates the development of next generation computational tools which can be used effectively and reliably in a design environment by non-CFD specialists. A computational tool, called Loci-STREAM is being developed for this purpose. It is a pressure-based, Reynolds-averaged Navier-Stokes (RANS) solver for generalized unstructured grids, which is designed to handle all-speed flows (incompressible to hypersonic) and is particularly suitable for solving multi-species flow in fixed-frame combustion devices. Loci-STREAM integrates proven numerical methods for generalized grids and state-of-the-art physical models in a novel rule-based programming framework called Loci which allows: (a) seamless integration of multidisciplinary physics in a unified manner, and (b) automatic handling of massively parallel computing. The objective of the ongoing work is to develop a robust simulation capability for combustion problems in rocket engines. As an initial step towards validating this capability, a model problem is investigated in the present study which involves a gaseous oxygen/gaseous hydrogen (GO2/GH2) shear coaxial single element injector, for which experimental data are available. The sensitivity of the computed solutions to grid density, grid distribution, different turbulence models, and different near-wall treatments is investigated. A refined grid, which is clustered in the vicinity of the solid walls as well as the flame, is used to obtain a steady state solution which may be considered as the best solution attainable with the steady-state RANS methodology. From a design point of view, quick turnaround times are desirable; with this in mind, coarser grids are also employed and the resulting solutions are evaluated with respect to the fine grid solution.

Thakur, Siddarth; Wright, Jeffrey

2006-01-01

398

Local strain and damage mapping in single trabeculae during three-point bending tests  

PubMed Central

The use of bone mineral density as a surrogate to diagnose bone fracture risk in individuals is of limited value. However, there is growing evidence that information on trabecular microarchitecture can improve the assessment of fracture risk. One current strategy is to exploit finite element analysis (FEA) applied to 3D image data of several mm-sized trabecular bone structures obtained from non-invasive imaging modalities for the prediction of apparent mechanical properties. However, there is a lack of FE damage models, based on solid experimental facts, which are needed to validate such approaches and to provide criteria marking elastic–plastic deformation transitions as well as microdamage initiation and accumulation. In this communication, we present a strategy that could elegantly lead to future damage models for FEA: direct measurements of local strains involved in microdamage initiation and plastic deformation in single trabeculae. We use digital image correlation to link stress whitening in bone, reported to be correlated to microdamage, to quantitative local strain values. Our results show that the whitening zones, i.e. damage formation, in the presented loading case of a three-point bending test correlate best with areas of elevated tensile strains oriented parallel to the long axis of the samples. The average local strains along this axis were determined to be (1.6 ± 0.9)% at whitening onset and (12 ± 4)% just prior to failure. Overall, our data suggest that damage initiation in trabecular bone is asymmetric in tension and compression, with failure originating and propagating over a large range of tensile strains.

Jungmann, R.; Szabo, M.E.; Schitter, G.; Tang, Raymond Yue-Sing; Vashishth, D.; Hansma, P.K.; Thurner, P.J.

2012-01-01

399

Single and reciprocal friction testing of micropatterned surfaces for orthopedic device design.  

PubMed

The use of micropatterning to create uniform surface morphologies has been cited as yielding improvements in the coefficient of friction during high velocity sliding contact. Studies have not been preformed to determine if these micropatterns could also be useful in biomedical applications, such as total joint replacement surfaces, where the lower sliding velocities are used. In addition, other factors such as lubricant viscosities and materials used are more tightly constrained. In this study, the effect of pattern geometry, feature size and lubricant on contact friction and surface damage was investigated using 316L steel in sliding contact with a stainless steel and polyethylene pins. Using a novel proprietary forming process that creates millions of microstructures in parallel, a variety of micropatterned surfaces were fabricated to study the influence of shape (oval, circular, square), geometry (depressions, pillars) and feature size (10, 50 and 100 mm) on both contact friction and surface damage. All samples were 316L stainless steel and the static and dynamic coefficients of friction when in contact with either a stainless steel or polyethylene counterface were measured in dry and lubricated conditions. All samples were characterized for surface uniformity and pattern aspect ratio using white light interferometry and optical microscope image analysis, and the coefficients of friction were measured for each surface/lubricant/pin system using a CETR scratch testing system. Results showed that round depressions with diameters of 10 ?m had a significantly lower steady state coefficient of friction than the non-patterned substrates or substrates with greater diameter depression patterns. In addition, our results showed that the single-pass coefficient of friction measurements were not good predictors of the steady state coefficient of friction values measured. PMID:22340690

Mitchell, N; Eljach, C; Lodge, B; Sharp, J L; Desjardins, J D; Kennedy, M S

2012-03-01

400

Status report of the single heater test chapter 4 integrated analyses  

SciTech Connect

The primary purposes of the Single Heater Test (SHT) are to study the thermal-mechanical responses of the heated block. The SHT is too small and does not have adequate access for a complete study of the coupled thermal-hydrological-chemical processes. The SHT is used as a shake-down/scoping study for the thermal-hydrological- chemical processes. For the thermal-hydrological process, the temporal and spatial variations of the moisture content in the heated block are monitored by neutron logging in Holes 15, 17, 22, and 23, electrical resistivity tomograph (ERT) in Holes 24 to 27. In addition, relative humidity, gas pressure, and temperature are measured in zones between packers in Holes 16 and 18. Temperature is also measured by resistance temperature devices (RTD) in the neutron logging holes (1 5, 17, 22, and 23). Chemical sensors were installed in Holes 20 and 21, but the sensors did not respond to the moisture in the rock. Water was collected from Zone 4 in Hole l6. Calculated temperature distribution and the measured ones are compared. The humidity and gas pressure measurements in Holes 16 and 18 will are discussed. The moisture content measured by neutron logging and ERT will be presented and discussed. Calculated saturation distributions are presented and compared with the neutron logging results and the ERT. The chemical composition of the water collected from Hole 16 is discussed. Fracture closing and opening based on the thermomechanical measurements are summarized. Air permeability changes measured in Holes 16 and 18 are presented. An integrated discussion is presented.

Lin, W., LLNL

1998-02-26

401

Developing a realistic FE analysis method for the welding of a NET single-bead-on-plate test specimen  

Microsoft Academic Search

A Net (A European network) single-bead-on-plate test specimen was modeled using FE method (Abaqus) in order to predict the final residual stress in the plate following welding to compare with measured distributions. The welding of the specimen was modeled using 3D uncoupled analysis. Because the complexity of the 3D analysis, sensitivity tests on it were expensive. A 2D FE mesh

X. Y. Shan; M. J. Tan; N. P. O’Dowd

2007-01-01

402

Field Test Evaluation of Conservation Retrofits of Low-Income Single Family Buildings in Wisconsin: Summary Report  

Microsoft Academic Search

During the winter of 1985-86, a retrofit field test was performed in 66 occupied, low-income, single-family homes in Madison, Wisconsin. The primary objectives of the field test were to (1) determine the measured energy savings and the relative benefits of a combination of envelope and mechanical equipment retrofits that were selected following a new audit-directed retrofit procedure, (2) determine the

2001-01-01

403

Single-Well-Gas-Sparging Tests for Assessing the Feasibility of In-situ Aerobic Treatment of CAH Mixtures  

Microsoft Academic Search

Single-well-gas-sparge tests were performed to assess the feasibility of in-situ aerobic cometabolism of chlorinated aliphatic hydrocarbons (CAHs), such as trichloroethylene (TCE) and cis-1,2-dichloroethylene (c-DCE), using propane and methane as growth substrates. The tests were performed in the saturate zone at the McClellan Air Force Base, CA. The effectiveness of gas sparging to stimulate indigenous propane-utilizers or methane-utilizers was evaluated in

Y. Kim; J. Istok; L. Semprini

2002-01-01

404

Modified single lap joint (MSLJ) test configuration for the determination of adhesive fracture energy  

Microsoft Academic Search

In this work, a modification has been proposed to the traditional single lap joint (SLJ) configuration, to overcome the wide scatter in the fracture toughness measurement due to adhesive fillets. This modification, referred to as the Modified Single Lap Joint (MSLJ), is made by implanting end pre-cracks in the adhesive layer at the center of the bond line in a

S. B. Kumar; I. Sridhar; S. Sivashanker; Asim Bag; S. O. Osiyemi

2005-01-01

405

Pressure transients characterize fractured Midale unit  

SciTech Connect

The Midale unit is a naturally fractured carbonate reservoir in the Williston basin of southeastern Saskatchewan. Recently, the Midale working-interest owners initiated a CO{sub 2}-flood pilot project with several closely spaced wells. A comprehensive interwell pressure-transient test program was conducted for reservoir-characterization purposes before pilot operations began. The combination of conventional, pulse, and interference tests resulted in a detailed local description of this naturally fractured reservoir. Selected pressure-transient data from the reservoir- characterization program was presented. The data illustrate the pressure-transient characteristics of an anisotropic, naturally fractured reservoir. Analytical techniques are reviewed, and an interpretation technique for multiwell pressure-transient tests wells with negative skins is included. A discussion of the pressure-transient behavior that is observed in wells with typical field spacing is included.

Beliveau, D. (SPE, Shell Canada Ltd. (CA))

1989-12-01

406

Tensile-mode fatigue tests and fatigue life predictions of single crystal silicon in humidity controlled environments  

Microsoft Academic Search

This paper reports on a tensile-mode fatigue test in a constant humidity, even in a very high humidity, to reveal the mechanism of fatigue fractures of MEMS materials. A newly developed tensile-mode fatigue tester using the electrostatic grip can control the humidity from 25% RH to 90% RH. Using this tester, the fatigue life and strength of single crystal silicon

Y. Yamaji; K. Sugano; O. Tabata; T. Tsuchiya

2007-01-01

407

Comparative Study of Specific Plowing Energy for Mild Steel and Composite Ceramics Using Single Grit Scratch Tests  

Microsoft Academic Search

The present research work compares the specific plowing energy requirement of two different materials: mild steel (ductile material) and composite ceramics (brittle material) using single grit scratch tests. The comparative study of two different materials will enhance the understanding of specific plowing energy. Specific plowing energy depends both on grinding process parameters as well as material property such as hardness.

Vijayender Singh; Sudarsan Ghosh; P. Venkateswara Rao

2011-01-01

408

FUSION METHOD FOR THE MEASUREMENT OF PLUTONIUM IN SOILS: SINGLE-LABORATORY EVALUATION AND INTERLABORATORY COLLABORATIVE TEST  

EPA Science Inventory

This report presents the results of a single-laboratory evaluation and an interlaboratory collaborative test of a method for measuring plutonium in soil. The method employs potassium fluoride and potassium pyrosulfate fusions to decompose a 10-gram sample, barium sulfate precipit...

409

Testing a Poisson Counter Model for Visual Identification of Briefly Presented, Mutually Confusable Single Stimuli in Pure Accuracy Tasks  

ERIC Educational Resources Information Center

The authors propose and test a simple model of the time course of visual identification of briefly presented, mutually confusable single stimuli in pure accuracy tasks. The model implies that during stimulus analysis, tentative categorizations that stimulus i belongs to category j are made at a constant Poisson rate, v(i, j). The analysis is…

Kyllingsbaek, Soren; Markussen, Bo; Bundesen, Claus

2012-01-01

410

Simplified single sample 13Carbon urea breath test for Helicobacter pylori: comparison with histology, culture, and ELISA serology  

Microsoft Academic Search

There is no ideal method for detecting Helicobacter pylori. The 'standard' 13Carbon urea breath test (13C-UBT), which involves collecting eight to 15 breath samples and subsequent costly analysis, was modified by pooling 21 samples of expired breath taken at five minute intervals for 40 minutes into a collecting bag, from which a single 20 ml aliquot was taken and analysed

R P Logan; R J Polson; J J Misiewicz; G Rao; N Q Karim; D Newell; P Johnson; J Wadsworth; M M Walker; J H Baron

1991-01-01

411

A Field-Tested Task Analysis for Creating Single-Subject Graphs Using Microsoft[R] Office Excel  

ERIC Educational Resources Information Center

Creating single-subject (SS) graphs is challenging for many researchers and practitioners because it is a complex task with many steps. Although several authors have introduced guidelines for creating SS graphs, many users continue to experience frustration. The purpose of this article is to minimize these frustrations by providing a field-tested

Lo, Ya-yu; Konrad, Moira

2007-01-01

412

Detection of acid production from carbohydrates by Riemerella anatipestifer and related organisms using the buffered single substrate test  

Microsoft Academic Search

One hundred and twenty-one Riemerella anatipestifer field strains from wild birds, domesticated poultry and pigs were examined for their ability to produce acid from carbohydrates by using conventional biochemical and buffered single substrate (BSS) test methods. The type strains of the species R. anatipestifer and taxometrically related genera Chryseobacterium and Bergeyella were included in the study. In contrast to 10

K.-H Hinz; M Ryll; B Köhler

1998-01-01

413

Dissolution Kinetics of Titanate-Based Ceramic Waste Forms: Results from Single-Pass Flow Tests on Radiation Damaged Specimens.  

National Technical Information Service (NTIS)

In this report, we summarize the results of our single-pass flow-through (SPFT) tests on titanate ceramics at Pacific Northwest National Laboratory. These titanate ceramics are candidate disposal forms for excess weapons plutonium that is obligated by tre...

J. P. Icenhower D. M. Strachan M. M. Lindberg E. A. Rodriguez J. L. Steele

2003-01-01

414

Impact Of Transient Inrush On MOV Starting  

Microsoft Academic Search

This paper is the result of a recent NRC concern with the impact of transient inrush current on motor operated valve (MOV) starting. It provides the background for this issue, discusses the accuracy of measured current traces, presents the theory behind transient inrush, analyzes a set of VOTES test data, and discusses its impact on motor starting to determine whether

R. H. Buchert; C. E. Beck

1993-01-01

415

Flow tests of a single fuel element coolant channel for a compact fast reactor for space power  

NASA Technical Reports Server (NTRS)

Water flow tests were conducted on a single-fuel-element cooling channel for a nuclear concept to be used for space power. The tests established a method for measuring coolant flow rate which is applicable to water flow testing of a complete mockup of the reference reactor. The inlet plenum-to-outlet plenum pressure drop, which approximates the overall core pressure drop, was measured and correlated with flow rate. This information can be used for reactor coolant flow and heat transfer calculations. An analytical study of the flow characteristics was also conducted.

Springborn, R. H.

1971-01-01

416

Functional Interrupts and Destructive Failures from Single Event Effect Testing of Point-Of-Load Devices  

NASA Technical Reports Server (NTRS)

We show examples of single event functional interrupt and destructive failure in modern POL devices. The increasing complexity and diversity of the design and process introduce hard SEE modes that are triggered by various mechanisms.

Chen, Dakai; Phan, Anthony; Kim, Hak; Swonger, James; Musil, Paul; LaBel, Kenneth

2013-01-01

417

Study on application of new single photon detection technique application research on agriculture test  

NASA Astrophysics Data System (ADS)

Compared with detecting tedium and complexity of current crop seeds, come up with a new single photon detection technique. Put seeds into camera bellows, process the single photon radiation. Then make an analysis and compare to crops spectrum by complicated circuitry and computer analysis software to acquire the quality of crops seeds. This analytical method enhances the work efficiency of disposable detect crops quality. It's also provides a good mirror scheme to detect and analyze other organisms quality.

He, Qiwen; Meng, Xiangcheng; Peng, Jiansheng

418

Finite Element Analyses and Instrumentation Layout for Single Coil Testing of TF Coils in HT-7U  

NASA Astrophysics Data System (ADS)

The HT-7U tokamak is a magnetically-confined full superconducting fusion device, consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF) coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wires made in Russian [1]. A single D-shaped toroidal field magnet coil will be tested for large and expensive magnets systems before assembling them in the toroidal configuration. This paper describes the layout of the instrumentation for a superconducting test facility based on the results of a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7U tokamak device. At the same time, the design of coil support structure in the test facility is particularly discussed in some detail.

Chen, Wenge; Weng, Peide

2003-10-01

419

Emerging optocoupler issues with energetic particle-induced transients and permanent radiation degradation  

SciTech Connect

Radiation-induced permanent degradation and single event transient effects for optocouplers are discussed in this paper. These two effects are independent to the first order and will be addressed separately. Displacement damage-induced degradation of optocoupler current transfer ratio is reviewed. New data are presented that show the importance of application specific testing and that generalized quantification of optocoupler CTR degradation can lead to incorrect predictions of actual circuit performance in a radiation environment. Data are given for various circuit loading and drive current parameters. Previous work that introduces the idea that two mechanisms exist for inducing transients on the optocoupler output is discussed. New data are presented that extends the evidence of this dual mechanism hypothesis. In this work measurements show that single event transient cross sections and transient propagation varies with circuit filtering. Finally, the authors discuss utilization of the optocouplers in the space environment. New data are applied to two examples: one on permanent degradation and the other on single event transient rates in high bandwidth applications.

Reed, R.A.; Barth, J.L.; LaBel, K.A. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States); Marshall, P.W.; Carts, M.A. [NRL/SFA, Largo, MD (United States)] [NRL/SFA, Largo, MD (United States); Johnston, A.H. [JPL, Pasadena, CA (United States)] [JPL, Pasadena, CA (United States); Marshall, C.J. [NRL, Washington, DC (United States)] [NRL, Washington, DC (United States); D`Ordine, M. [Ball Aerospace, Boulder, CO (United States)] [Ball Aerospace, Boulder, CO (United States); Kim, H.S. [Jackson and Tull Chartered Engineers, Washington, DC (United States)] [Jackson and Tull Chartered Engineers, Washington, DC (United States)

1998-12-01

420

Experimental Results of Single Screw Mechanical Tests. A Follow-Up to SAND2005-6036.  

National Technical Information Service (NTIS)

The work reported here was conducted to address issues raised regarding mechanical testing of attachment screws described in SAND2005-6036, as well as to increase the understanding of screw behavior through additional testing. Efforts were made to evaluat...

J. S. Korellis K. L. Lee S. Lee X. McFadden

2006-01-01