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1

Application of a novel test system to characterize single-event transients at cryogenic temperatures  

Microsoft Academic Search

This manuscript presents details of a customized test system that enables carrying out broadbeam heavy ion SEE radiation testing of semiconductor devices at cryogenic temperatures, while the device is biased and operational, and its application to measure the temperature dependence of single event transients in a CMOS circuit. The cryogenic test system is lightweight and portable, and allows use of

Vishwanath Ramachandran; Matthew J. Gadlage; Jonathan R. Ahlbin; Michael L. Alles; R. A. Reed; B. L. Bhuva; L. W. Massengill; J. D. Black; C. N. Foster

2009-01-01

2

Analysis of the single-blow transient testing technique for perforated plate heat exchangers  

NASA Astrophysics Data System (ADS)

An analysis of the single-blow transient testing technique for heat exchanger surfaces is made for perforated plate and similar discontinuous surfaces. The model assumes that there is no temperature variation across each plate, and allows for axial conduction in spacers: the resulting axial fluid temperature profile is discontinuous, rather than the usual continuous profile. Numerical solutions are obtained to the resulting set of coupled first-order differential equations for a step change in inlet fluid temperature. Results are presented in tabular form, which allow the heat transfer coefficients to be calculated from test data using the maximum slope technique.

Rodriguez, Jose I.; Mills, Anthony F.

1990-09-01

3

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

4

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

5

Columbia University flow instability experimental program: Volume 12. Single annulus transient test program data tables: Part 1  

SciTech Connect

The single annulus test program was designed to investigate the onset of flow instability in an annular geometry similar to the fuel assemblies used in the Savannah River Site production reactors. Data files were transmitted from Columbia University to Savannah River Site in a DOS compatible format. This report provides a hardcopy version of the electronic media data files.

Coutts, D.A.

1993-09-01

6

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

7

Igniter heater EMI transient test  

NASA Technical Reports Server (NTRS)

Testing to evaluate Redesigned Solid Rocket Motor igniter heater electromagnetic interference (EMI) effects on the Safe and Arm (S and A) device was completed. It was suspected that EMI generated by the igniter heater and it's associated electromechanical relay could cause a premature firing of the NASA Standard Initiators (NSIs) inside the S and A. The maximum voltage induced into the NSI fire lines was 1/4 of the NASA specified no-fire limit of one volt (SKB 26100066). As a result, the igniter heaters are not expected to have any adverse EMI effects on the NSIs. The results did show, however, that power switching causes occasional high transients within the igniter heater power cable. These transients could affect the sensitive equipment inside the forward skirt. It is therefore recommended that the electromechanical igniter heater relays be replaced with zero crossing solid state relays. If the solid state relays are installed, it is also recommended that they be tested for EMI transient effects.

Cook, M.

1989-01-01

8

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

9

Transient Rayleigh scattering from single semiconductor nanowires  

SciTech Connect

Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.

Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M. [Department of Physics, University of Cincinnati, Cincinnati, OH 45221-0011 (United States); Yarrison-Rice, Jan M. [Department of Physics, Miami University, Oxford, OH 45056 (United States); Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

2013-12-04

10

Transient Rayleigh scattering from single semiconductor nanowires  

NASA Astrophysics Data System (ADS)

Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.

Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M.; Yarrison-Rice, Jan M.; Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati

2013-12-01

11

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

12

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

13

Anisotropy of transient photoconductivity in functionalized pentacene single crystals  

E-print Network

to their potential applications in thin film transis- tors, organic light-emitting diodes, solar cells, etc.1 Thin single crystal platelets and polycrystalline thin films are par- ticularly interesting for applicationsAnisotropy of transient photoconductivity in functionalized pentacene single crystals O

Ostroverkhova, Oksana

14

PFR/Treat Safety Experiments: HEDL Transient Test Program Engineering Test Plan  

SciTech Connect

The purpose of the PFR/TREAT Safety Test Program is to obtain experimental data of fuel pin behavior during hypothetical, unprotected accidents for cores of large liquid metal cooled fast breeder reactors. The steady state and transient experiments, which will be performed under the joint program, are to be as prototypic of fast reactor performance as is possible. The specific objectives of this document are: (1) dictate the activities and responsibilities for the HEDL Transient Test Program; (2) specify the technical requirements for the CO4, CO5, CO6 and CO7 test train (SPTTs); and (3) specify the technical requirement for the CO6 and CO7 Single Pin Test Loops (SPTLs). Specific requirements for single pin loop experiments beyond CO7 and multi pin experiments will be covered in the addenda to this test plan.

Hoffman, M.A.; Metcalf, I.L.; Myron, D.L.

1981-03-01

15

Transient testing of perforated plate matrix heat exchangers  

NASA Astrophysics Data System (ADS)

Till recently, perforated plate matrix heat exchangers (MHEs) were used mainly in helium liquefaction systems and Brayton cycle refrigerators. Currently they are also being used in Kleemenko or J-T refrigerators operating with a mixture of gases. It is now well understood that the effectiveness of a MHE is strongly dependent on the number of plate-spacer pairs used. It has also been shown that the traditional methods used for reducing the transient single blow method to determine the heat transfer coefficients cannot be used for MHEs. In this paper we show that the traditional methods can indeed be used for determining the heat transfer coefficients using the transient testing methods, provided certain conditions are met.

Krishnakumar, K.; Venkatarathnam, G.

2003-02-01

16

Transient Molecular Transfer During Vacuum Testing  

NASA Technical Reports Server (NTRS)

A common question in contamination budgeting involves the loss of collected volatiles during ambient I&T activity under vacuum and the resultant cross-contamination from outgassing. (1) How much of the material collected under ambient conditions evaporates under vacuum? (2) Why do pristine surfaces sometimes show increased molecular contamination after vacuum bakeout? (3) How much of the collected molecular contamination is transient (i.e. migratory) and how much is permanent? Measuring the transient deposition may be accomplished using a thermally passive QCM

Perry, Radford L.

2011-01-01

17

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

18

Single sideband Ronchi test.  

PubMed

A new lateral shear interferometer based on the Ronchi grating is proposed. The normal Ronchi test is impaired by multiple beam interference (Talbot effect). Furthermore, the fringe pattern is somewhat restricted by fringe number and orientation. The new shear interferometer suppresses the Talbot effect by spatial filtering and by using a second grating enables arbitrary fringe orientation and number. PMID:20333011

Schwider, J

1981-08-01

19

Transient current testing of 0.25 ?m CMOS devices  

Microsoft Academic Search

Transient current testing (IDDT) has been often cited as an alternative and\\/or supplement to IDDQ testing. The effectiveness of our IDDT test method is compared with IDDQ as well as with SA-based voltage testing for devices produced in 0.25 ?m technology. For these devices a large vector-to-vector spread in IDDT is observed. This spread is investigated together with the die-to-die

Bram Kruseman; Peter Janssen; Victor Zieren

1999-01-01

20

SINGLE FIBER TESTING VIA FAVIMAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cotton fiber is usually tested in bulk form utilizing a mass or beard of fibers to be presented to a test instrument for measurement. There are many reasons for this, not the least of which is that handling single cotton fibers is tedious and time consuming. Cotton breeders are being pushed to mak...

21

Alternatives Analysis for the Resumption of Transient Testing Program  

SciTech Connect

An alternatives analysis was performed for resumption of transient testing. The analysis considered eleven alternatives – including both US international facilities. A screening process was used to identify two viable alternatives from the original eleven. In addition, the alternatives analysis includes a no action alternative as required by the National Environmental Policy Act (NEPA). The alternatives considered in this analysis included: 1. Restart the Transient Reactor Test Facility (TREAT) 2. Modify the Annular Core Research Reactor (ACRR) which includes construction of a new hot cell and installation of a new hodoscope. 3. No Action

Lee Nelson

2013-11-01

22

RELAP5 Prediction of Transient Tests in the RD-14 Test Facility  

SciTech Connect

Although the RELAP5 computer code has been developed for best-estimate transient simulation of a pressurized water reactor and its associated systems, it could not assess the thermal-hydraulic behavior of a Canada deuterium uranium (CANDU) reactor adequately. However, some studies have been initiated to explore the applicability for simulating a large-break loss-of-coolant accident in CANDU reactors. In the present study, the small-reactor inlet header break test and the steam generator secondary-side depressurization test conducted in the RD-14 test facility were simulated with the RELAP5/MOD3.2.2 code to examine its extended capability for all the postulated transients and accidents in CANDU reactors. The results were compared with experimental data and those of the CATHENA code performed by Atomic Energy of Canada Limited.In the RELAP5 analyses, the heated sections in the facility were simulated as a multichannel with five pipe models, which have identical flow areas and hydraulic elevations, as well as a single-pipe model.The results of the small-reactor inlet header break and the steam generator secondary-side depressurization simulations predicted experimental data reasonably well. However, some discrepancies in the depressurization of the primary heat transport system after the header break and consequent time delay of the major phenomena were observed in the simulation of the small-reactor inlet header break test.

Lee, Sukho [Korea Institute of Nuclear Safety (Korea, Republic of); Kim, Manwoong [Korea Institute of Nuclear Safety (Korea, Republic of); Kim, Hho-Jung [Korea Institute of Nuclear Safety (Korea, Republic of); Lee, John C. [University of Michigan (United States)

2005-09-15

23

Intelligent transient transitions detection of LRE test bed  

NASA Astrophysics Data System (ADS)

Health Monitoring Systems is an implementation of monitoring strategies for complex systems whereby avoiding catastrophic failure, extending life and leading to improved asset management. A Health Monitoring Systems generally encompasses intelligence at many levels and sub-systems including sensors, actuators, devices, etc. In this paper, a smart sensor is studied, which is use to detect transient transitions of liquid-propellant rocket engines test bed. In consideration of dramatic changes of variable condition, wavelet decomposition is used to work real time in areas. Contrast to traditional Fourier transform method, the major advantage of adding wavelet analysis is the ability to detect transient transitions as well as obtaining the frequency content using a much smaller data set. Historically, transient transitions were only detected by offline analysis of the data. The methods proposed in this paper provide an opportunity to detect transient transitions automatically as well as many additional data anomalies, and provide improved data-correction and sensor health diagnostic abilities. The developed algorithms have been tested on actual rocket test data.

Zhu, Fengyu; Shen, Zhengguang; Wang, Qi

2013-01-01

24

Recording and time expansion technique for high-speed, single-shot transient video signal  

NASA Technical Reports Server (NTRS)

High-speed, single-shot, transient voltage is recorded on a video tape recorder, which, when played back, converts the single signal to a repetitive signal. This drives a sample data translator which lengthens the original transient production time, suiting it to an x-y plotter or computer tape recorder use.

Hruby, R. J.; Sander, R. C.

1967-01-01

25

Parametric Thermal Models of the Transient Reactor Test Facility (TREAT)  

SciTech Connect

This work supports the restart of transient testing in the United States using the Department of Energy’s Transient Reactor Test Facility at the Idaho National Laboratory. It also supports the Global Threat Reduction Initiative by reducing proliferation risk of high enriched uranium fuel. The work involves the creation of a nuclear fuel assembly model using the fuel performance code known as BISON. The model simulates the thermal behavior of a nuclear fuel assembly during steady state and transient operational modes. Additional models of the same geometry but differing material properties are created to perform parametric studies. The results show that fuel and cladding thermal conductivity have the greatest effect on fuel temperature under the steady state operational mode. Fuel density and fuel specific heat have the greatest effect for transient operational model. When considering a new fuel type it is recommended to use materials that decrease the specific heat of the fuel and the thermal conductivity of the fuel’s cladding in order to deal with higher density fuels that accompany the LEU conversion process. Data on the latest operating conditions of TREAT need to be attained in order to validate BISON’s results. BISON’s models for TREAT (material models, boundary convection models) are modest and need additional work to ensure accuracy and confidence in results.

Bradley K. Heath

2014-03-01

26

100 MHz fiber optic single transient gamma ray detection system  

SciTech Connect

A fiber optic system has been developed to measure single transient gamma rays. The gamma ray signature is converted to light by the Cerenkov process in a 20 cm length of radiation resistant optical fiber. The signal is transmitted over 1 km of optical fiber and detected by state-of-the-art, 175 MHz analog receivers. The receivers are based on silicon PIN detectors with transimpedance hybrid amplifiers and two stages of power amplification. The dc coupled receivers have less than 2% distortion up to 5 volts with less than 10 mV rms noise and a responsivity of 37,500 V/watt at 800 nm. A calibration system measures relative fiber to fiber transit time delays and ''system'' sensitivity. System bandwidth measurements utilized an electron linear accelerator (Linac) with a 50 ps electron pulse as the Cerenkov light source. The system will be described with supporting calibrationa and characterization data of parts of the system and the whole system.

Ogle, J.W.; Smith, R.C.; Ward, M.; Ramsey, R.; Hollabaugh, J.

1984-01-01

27

Transient oxidation of Single-Crystal ?-NiAl  

Microsoft Academic Search

The transient oxidation of ?-NiAl in air at 800 ?C and 1100 ?C has been studied using electron microscopy. The oxide scale\\u000a consists predominatly of metastable Al2O3 phases. ?-Al2O3 is the major oxide phase within 10.0 hr of oxidation at 800 ?C and 0.1 hr at 1100 ?C. The scales form epitaxially on (001)? and (012)? specimens throughout the transient

J. Doychak; J. L. Smialek; T. E. Mitchell

1989-01-01

28

Transient computation fluid dynamics modeling of a single proton exchange membrane fuel cell with serpentine channel  

Microsoft Academic Search

The proton exchange membrane fuel cell (PEMFC) has become a promising candidate for the power source of electrical vehicles because of its low pollution, low noise and especially fast startup and transient responses at low temperatures. A transient, three-dimensional, non-isothermal and single-phase mathematical model based on computation fluid dynamics has been developed to describe the transient process and the dynamic

Guilin Hu; Jianren Fan

2007-01-01

29

Temperature Dependence of Digital Single-Event Transients in Bulk and Fully-Depleted SOI Technologies  

E-print Network

Factors that affect single-event transient pulse widths, such as drift, diffusion, and parasitic bipolar transistor parameters, are also strong functions of operating temperature. In this paper, SET pulse-width measurements ...

Gouker, Pascale M.

30

Exciton diffusion in semiconducting single-walled carbon nanotubes studied by transient absorption microscopy  

E-print Network

Spatiotemporal dynamics of excitons in isolated semiconducting single-walled carbon nanotubes are studied using transient absorption microscopy. Differential reflection and transmission of an 810-nm probe pulse after excitation by a 750-nm pump...

Ruzicka, Brian A.; Wang, Rui; Lohrman, Jessica; Ren, Shenqiang; Zhao, Hui

2012-11-09

31

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

Code of Federal Regulations, 2010 CFR

...false Which duty cycles do I use for transient testing? 1039.510 Section 1039...510 Which duty cycles do I use for transient testing? (a) Measure emissions...dynamometer with one of the following transient duty cycles to determine whether it...

2010-07-01

32

Pressure-Transient Testing of Water-Injection Wells  

Microsoft Academic Search

This paper presents an interpretation method for injectivity and falloff testing in a single-layer oil reservoir that is under waterflooding and develops analytical solutions for pressure and saturation distributions. The effects of relative permeability, wellbore storage, and skin are considered in these solutions. New field-dependent type curves for falloff tests, which exhibit features that do not appear in the currently

Maghsood Abbaszadeh; Medhat Kamal

1989-01-01

33

Tidal volume single-breath washin of SF6 and CH4 in transient microgravity  

NASA Technical Reports Server (NTRS)

We performed tidal volume single-breath washins (SBW) by using tracers of different diffusivity and varied the time spent in microgravity (microG) before the start of the tests to look for time-dependent effects. SF(6) and CH(4) phase III slopes decreased by 35 and 26%, respectively, in microG compared with 1 G (P < 0.05), and the slope difference between gases disappeared. There was no effect of time in microG, suggesting that neither the hypergravity period preceding microG nor the time spent in microG affected gas mixing at volumes near functional residual capacity. In previous studies using SF(6) and He (Lauzon A-M, Prisk GK, Elliott AR, Verbanck S, Paiva M, and West JB. J Appl Physiol 82: 859-865, 1997), the vital capacity SBW showed an increase in slope difference between gases in transient microG, the opposite of the decrease in sustained microG. In contrast, tidal volume SBW showed a decrease in slope difference in both microG conditions. Because it is only the behavior of the more diffusive gas that differed between maneuvers and microG conditions, we speculate that, in the previous vital capacity SBW, the hypergravity period preceding the test in transient microG provoked conformational changes at low lung volumes near the acinar entrance.

Dutrieue, Brigitte; Paiva, Manuel; Verbanck, Sylvia; Le Gouic, Marine; Darquenne, Chantal; Prisk, G. Kim

2003-01-01

34

Transient thermal model of the continuous single-wheel thin-strip casting process  

NASA Astrophysics Data System (ADS)

A transient heat-transfer model (STRIP1D) has been developed to simulate the single-roll continuous strip-casting process. The model predicts temperature in the solidifying strip coupled with heat transfer in the rotating wheel, using an explicit finite difference procedure. The model has been calibrated using strip thickness data from a test caster at ARMCO Inc. (Middletown, OH) and verified with a range of other available measurements. The strip/wheel interface contact resistance and heat transfer were investigated in particular, and an empirical formula to calculate this heat-transfer coefficient as a function of contact time was obtained. Wheel temperature and final strip thickness are investigated as a function of casting speed, liquid steel pool depth, superheat, coatings on the wheel hot surface, strip detachment point, wheel wall thickness, and wheel material.

Li, Guowei; Thomas, Brian G.

1996-06-01

35

Transient Testing of Nuclear Fuels and Materials in United States  

SciTech Connect

The US Department of Energy (DOE) has been engaged in an effort to develop and qualify next generation LWR fuel with enhanced performance and safety and reduced waste generation since 2010. This program, which has emphasized collaboration between the DOE, U.S. national laboratories and nuclear industry, was refocused from enhanced performance to enhanced accident tolerance following the events at Fukushima in 2011. Accident tolerant fuels have been specifically described as fuels that, in comparison with standard UO2-Zircaloy, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, as well as design-basis and beyond design-basis events. The program maintains an ambitious goal to insert a lead test assembly (LTA) of the new design into a commercial power reactor by 2022 .

Daniel M. Wachs

2012-12-01

36

Two-dimensional steady-state and transient analysis of single-cell thermionic fuel elements  

SciTech Connect

A two-dimensional transient model is developed to simulate steady-state and transient operations of single-cell thermionic fuel elements (TFEs). Model predictions are in good agreement with published data to within 4.5 and 5.5% for fission and electrically heated TFEs of the TOPAZ-II type, respectively. In addition, the results of a transient analysis simulating the startup of an electrically heated TFE, following a step function increase in thermal power, are in presented and discussed.

El-Genk, M.S.; Xue, H. (Univ. of New Mexico, Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies)

1994-10-01

37

Transient Analysis Used to Study Thermal Radiation Effects in Single and Composite Semitransparent Layers  

NASA Technical Reports Server (NTRS)

In a continuing in-house program at the NASA Lewis Research Center, analytical and numerical methods are being developed to apply radiative analysis to predict transient temperature distributions and heat flows in partially transmitting materials. Results have been obtained for a single plane layer, and a transient analysis is being developed for a two-layer composite where each layer has a different refractive index. Because the ceramic refractive indices are larger than one, internal reflections are produced at the surfaces and at the internal interface. Reflections tend to distribute energy within a layer, and this affects the transient temperature distributions.

1996-01-01

38

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

39

Barometric pressure transient testing applications at the Nevada Test Site: formation permeability analysis. Final report  

SciTech Connect

The report evaluates previous investigations of the gas permeability of the rock surrounding emplacement holes at the Nevada Test Site. The discussion sets the framework from which the present uncertainty in gas permeability can be overcome. The usefulness of the barometric pressure testing method has been established. Flow models were used to evaluate barometric pressure transients taken at NTS holes U2fe, U19ac and U20ai. 31 refs., 103 figs., 18 tabs. (ACR)

Hanson, J.M.

1984-12-01

40

Transient productivity index for numerical well test simulations  

SciTech Connect

The most difficult aspect of numerical simulation of well tests is the treatment of the Bottom Hole Flowing (BHF) Pressure. In full field simulations, this pressure is derived from the Well-block Pressure (WBP) using a numerical productivity index which accounts for the grid size and permeability, and for the well completion. This productivity index is calculated assuming a pseudo-steady state flow regime in the vicinity of the well and is therefore constant during the well production period. Such a pseudo-steady state assumption is no longer valid for the early time of a well test simulation as long as the pressure perturbation has not reached several grid-blocks around the well. This paper offers two different solutions to this problem: (1) The first one is based on the derivation of a Numerical Transient Productivity Index (NTPI) to be applied to Cartesian grids; (2) The second one is based on the use of a Corrected Transmissibility and Accumulation Term (CTAT) in the flow equation. The representation of the pressure behavior given by both solutions is far more accurate than the conventional one as shown by several validation examples which are presented in the following pages.

Blanc, G.; Ding, D.Y.; Ene, A. [Institut Francais du Petrole, Pau (France)] [and others

1997-08-01

41

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

42

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

43

40 CFR Appendix E to Subpart S of... - Transient Test Driving Cycle  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Transient Test Driving Cycle E Appendix E to Subpart S of Part 51 Protection of Environment ENVIRONMENTAL...Maintenance Program Requirements Pt. 51, Subpt. S, App. E Appendix E to Subpart S of Part 51—Transient Test...

2010-07-01

44

CHARDIN: An Off-Chip Transient Current Monitor with Digital Interface for Production Testing  

Microsoft Academic Search

We present a measurement module that computes the charge from the transient supply current and provides a digital value of this magnitude. The module is constructed to provide a feasible implementation of transient current testing in production-like environments. Experimental results demonstrate up to 1 GHz analog bandwidth, while the effective test speed is mainly determined by the A\\/D converter included

B. Alorda; B. Bloechel; Ali Keshavarzi; Jaume Segura

2003-01-01

45

Integrated, digital experiment transient control and safety protection of an in-pile test  

Microsoft Academic Search

The Sodium Loop Safety Facility experimental program has demonstrated that in-pile loop fuel failure transient tests can be digitally controlled and protected with reliability and precision. This was done in four nuclear experiments conducted in the Engineering Test Reactor operated by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory. Loop sodium flow and reactor power transients can

R. W. Thomas; R. F. Whitacre; W. B. Klingler

1982-01-01

46

Transient modelling of single-electron transistors for efficient circuit simulation by SPICE  

E-print Network

Transient modelling of single-electron transistors for efficient circuit simulation by SPICE Y simulation by SPICE. The developed model is based on a linearised equivalent circuit and the solution of a master equation is done by the programming capabilities of the SmartSpice. Exact delineation of several

Hwang, Sung Woo

47

Assessing Alpha Particle-Induced Single Event Transient Vulnerability in a 90-nm CMOS Technology  

Microsoft Academic Search

The charge required to store (or potentially disturb) a digital logic signal decreases as feature sizes in advanced devices decrease. As a result, the soft-error rate has become a significant reliability issue for highly scaled technologies. Single-event transients (SETs), or glitches that originate in logic circuits, are one of the most important categories of soft errors. In this letter, SETs

Matthew J. Gadlage; Ronald D. Schrimpf; Balaji Narasimham; Jonathan A. Pellish; Kevin M. Warren; Robert A. Reed; Robert A. Weller; Bharat L. Bhuva; Lloyd W. Massengill; Xiaowei Zhu

2008-01-01

48

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

49

Single event transient (SET) sensitivity of radiation hardened and COTS voltage comparators  

Microsoft Academic Search

The single event transient (SET) sensitivity of a radiation hardened voltage comparator type with vertical input transistors is compared with that observed for a COTS device type made up of lateral transistors. The cause of the difference in sensitivity is investigated

S. H. Crain; K. B. Crawford; S. C. Moss; S. D. LaLumondiere

2000-01-01

50

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

51

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

PubMed Central

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) Images Figure 1 Figure 2 Figure 3 Figure 9 PMID:7658365

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

1995-01-01

52

An analog cell to detect single event transients in voltage references  

NASA Astrophysics Data System (ADS)

A reliable voltage reference is mandatory in mixed-signal systems. However, this family of components can undergo very long single event transients when operating in radiation environments such as space and nuclear facilities due to the impact of heavy ions. The purpose of the present paper is to demonstrate how a simple cell can be used to detect these transients. The cell was implemented with typical COTS components and its behavior was verified by SPICE simulations and in a laser facility. Different applications of the cell are explored as well.

Franco, F. J.; Palomar, C.; Izquierdo, J. G.; Agapito, J. A.

2015-01-01

53

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

54

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

55

Single event transient modeling and mitigation techniques for mixed-signal delay locked loop (DLL) and clock circuits  

NASA Astrophysics Data System (ADS)

The purpose of this PhD work has been to investigate, model, test, develop and provide hardening techniques and guidelines for the mitigation of single event transients (SETs) in analog mixed-signal (AMS) delay locked loops (DLLs) for radiation-hardened applications. Delay-locked-loops (DLLs) are circuit substructures that are present in complex ASIC and system-on-a-chip designs. These circuits are widely used in on-chip clock distribution systems to reduce clock skew, to reduce jitter noise, and to recover clock signals at regional points within a global clock distribution system. DLLs are critical to the performance of many clock distribution systems, and in turn, the overall performance of the associated integrated system; as such, complex systems often employ multiple DLLs for clock deskew and distribution tasks. In radiation environments such as on-orbit, these critical circuits represent at-risk points of malfunction for large sections of integrated circuits due to vulnerabilities to radiation-generated transients (i.e. single event transients) that fan out across the system. The analysis of single event effects in analog DLLs has shown that each DLL sub-circuit primitive is vulnerable to single event transients. However, we have identified the voltage controlled delay line (VCDL) sub-circuit as the most sensitive to radiation-induced single event effects generating missing clock pulses that increase with the operating frequency of the circuit. This vulnerability increases with multiple instantiation of DLLs as clock distribution nodes throughout an integrated system on a chip. To our knowledge, no complete work in the rad-hard community regarding the hardening of mixed-signal DLLs against single event effects (missing pulses) has been developed. Most of the work present in the literature applies the "brute force" and well-established digital technique of triple modular redundancy (TMR) to the digital subcomponents. We have developed two novel design techniques for the mitigation of DLL missing pulses that are fully implementable in modern CMOS technologies. These techniques offer to the community the choice of hardening using a restoring current technique in the VCDL sub-circuit to inhibit the creation of missing pulse errors, or using a combinational logic error monitoring technique to correct missing pulses after they occur in real time. We have implemented both of these techniques with minimal area and power penalties when compared to TMR. In addition, these hardening techniques have been extrapolated to other clock circuits, such as digital PLLs. The first hardening technique uses a hardened complementary differential pair VCDL to increase the critical charge (Qcrit) necessary for single event transient generation and thus mitigate missing pulses at the source. Our implementation of this technique at 180 nm, 90 nm and 40 nm required less than a 2% area penalty over a non-hardened design. To experimentally validate this technique, hardened VCDLs were designed and fabricated in 180-nm IBM and 40-nm UMC technologies, then tested at the Naval Research Lab in Washington D.C. The second hardening technique, based on combinational logic pulse monitoring, uses an error correction circuit to mitigate the missing pulses as they occur. This ECC technique is implemented via a "peeled" VCDL (i.e. each transistor is split in area but doubled in multiplicity). We have shown the effectiveness of this technique by implementing it in a Xilinx Virtex 5 FPGA. Furthermore, this new ECC technique is independent of technology scaling -- a highly valuable attribute for sub-50 nm design applications. In addition to the formulation, simulation, prototyping, fabrication, and testing of these new hardening solutions, we developed a unique single event analytical model to guide future hardened DLL designs at advanced technology nodes. The model was furthermore generalized to PLL and DLLs. These analytical models were then used to provide a set of equations to the designer for important insight into hardening choices an

Maillard, Pierre

56

Steady state and transient photoconductivity of thin film polydiacetylene single crystals  

Microsoft Academic Search

Charge carrier generation and transport mechanisms in polydiacetylene thin film single crystals, poly-PTS (2,4-hexadiyne 1,6-diol bis-(p-toluene sulfonate)) and poly-BTFP (bis-(4-n-butyl 2,3,5,6-tetra fluorophenyl) butadiyne), are studied by using steady state and transient photoconductivity techniques. The electric field dependence of the steady state photocurrent is superlinear for both samples. Dependence of photocurrent on incident light polarization has been investigated. The polarization dependence

Y. Yang; J. Y. Lee; P. Miller; L. Li; J. Kumar

1991-01-01

57

Single-photon avalanche diode arrays for fast transients and adaptive optics  

Microsoft Academic Search

An instrumentation based on a silicon monolithic array of 60 photon counters [single-photon avalanche diode array (SPADA)] for state-of-the-art measurements of fast transient phenomena and adaptive optics (AO) is presented. The fabricated solid-state photon counters are rugged, easy to be integrated in the optical system, free from read-out noise, and provide very fast frame rates (> 10 kHz) and nanosecond

Franco Zappa; Simone Tisa; Sergio Cova; Piera Maccagnani; Domenico Bonaccini Calia; Roberto Saletti; Roberto Roncella; Giovanni Bonanno; Massimiliano Belluso

2006-01-01

58

Transient Dynamics in Magnetic Force Microscopy for a Single-Spin Measurement  

E-print Network

We analyze a single-spin measurement using a transient process in magnetic force microscopy (MFM) which could increase the maximum operating temperature by a factor of Q (the quality factor of the cantilever) in comparison with the static Stern-Gerlach effect. We obtain an exact solution of the master equation, which confirms this result. We also discuss the conditions required to create a macroscopic Schrodinger cat state in the cantilever.

G. P. Berman; F. Borgonovi; G. V. Lopez; V. I. Tsifrinovich

2002-10-01

59

Protoplast isolation and transient gene expression in the single-cell C 4 species, Bienertia sinuspersici  

Microsoft Academic Search

Although transient gene expression using reporters such as green fluorescent protein is a versatile tool for examining gene\\u000a functions and intracellular protein trafficking, the establishment of a highly efficient gene manipulation method remains\\u000a a challenge in many plant species. A reliable transformation protocol has not yet been established for the three single-cell\\u000a C4 species, despite their potential of serving as

Shiu-Cheung Lung; Makoto Yanagisawa; Simon D. X. Chuong

2011-01-01

60

Single event phenomena: Testing and prediction  

NASA Technical Reports Server (NTRS)

Highly integrated microelectronic devices are often used to increase the performance of satellite systems while reducing the system power dissipation, size, and weight. However, these devices are usually more susceptible to radiation than less integrated devices. In particular, the problem of sensitivity to single event upset and latchup is greatly increased as the integration level is increased. Therefore, a method for accurately evaluating the susceptibility of new devices to single event phenomena is critical to qualifying new components for use in space systems. This evaluation includes testing devices for upset or latchup and extrapolating the results of these tests to the orbital environment. Current methods for testing devices for single event effects are reviewed, and methods for upset rate prediction, including a new technique based on Monte Carlo simulation, are presented.

Kinnison, James D.

1992-01-01

61

ASST Interconnect Region single phase pressure tests  

SciTech Connect

The Accelerator System String Test (ASST) single phase line was pressure tested to meet ASME B31.3-1990 piping code requirements. Two test specimens, one without a bellows assembly and one with a bellows assembly, were tested under hydrostatic pressure in 0.689 MPa (100psi) increments. All parts met code requirements except the bellows squirm protector, which met ASST-rated pressure levels but not Collider-rated levels, due to inadequate tab weld quality. Extra support such as hose clamps and possible minor redesign would allow the squirm protector to meet ASME code requirements for the Collider.

Mendoza, R.

1992-08-01

62

Effects of Ionizing Radiation on Digital Single Event Transients in a 180-nm Fully Depleted SOI Process  

E-print Network

Effects of ionizing radiation on single event transients are reported for Fully Depleted SOI (FDSOI) technology using experiments and simulations. Logic circuits, i.e. CMOS inverter chains, were irradiated with cobalt-60 ...

Keast, Craig L.

63

Dissolution chemistry and biocompatibility of single-crystalline silicon nanomembranes and associated materials for transient electronics.  

PubMed

Single-crystalline silicon nanomembranes (Si NMs) represent a critically important class of material for high-performance forms of electronics that are capable of complete, controlled dissolution when immersed in water and/or biofluids, sometimes referred to as a type of "transient" electronics. The results reported here include the kinetics of hydrolysis of Si NMs in biofluids and various aqueous solutions through a range of relevant pH values, ionic concentrations and temperatures, and dependence on dopant types and concentrations. In vitro and in vivo investigations of Si NMs and other transient electronic materials demonstrate biocompatibility and bioresorption, thereby suggesting potential for envisioned applications in active, biodegradable electronic implants. PMID:24684516

Hwang, Suk-Won; Park, Gayoung; Edwards, Chris; Corbin, Elise A; Kang, Seung-Kyun; Cheng, Huanyu; Song, Jun-Kyul; Kim, Jae-Hwan; Yu, Sooyoun; Ng, Joanne; Lee, Jung Eun; Kim, Jiyoung; Yee, Cassian; Bhaduri, Basanta; Su, Yewang; Omennetto, Fiorenzo G; Huang, Yonggang; Bashir, Rashid; Goddard, Lynford; Popescu, Gabriel; Lee, Kyung-Mi; Rogers, John A

2014-06-24

64

Discussion on low-voltage transient impulse test access system  

Microsoft Academic Search

Beijing Products Quality supervision and inspection institute proposed Automotive Test Center, the programs of the test transformer substation connecting into power system have been compared in this paper. Low Voltage impulse test has shown its influence on the energy quality of the system voltage. The range of voltage sag is rested with the test capacity, the larger of the capacity

Li Xue-nan; Li Wei; Liu Zhao-yan

2010-01-01

65

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 ...

66

Mechanism of single-event transient pulse quenching between dummy gate isolated logic nodes  

NASA Astrophysics Data System (ADS)

As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes. The so-called single-event transient (SET) pulse quenching induced by single-event charge sharing collection has been widely studied. In this paper, SET pulse quenching enhancement is found in dummy gate isolated adjacent logic nodes compared with that isolated by the common shallow trench isolation (STI). The physical mechanism is studied in depth and this isolation technique is explored for SET mitigation in combinational standard cells. Three-dimensional (3D) technology computer-aided design simulation (TCAD) results show that this technique can achieve efficient SET mitigation. Project supported by the National Natural Science Foundation of China (Grant No. 61376109) and the Opening Project of National Key Laboratory of Science and Technology on Reliability Physics and Application Technology of Electrical Component, China (Grant No. ZHD201202).

Chen, Jian-Jun; Chi, Ya-Qing; Liang, Bin

2015-01-01

67

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

68

Combined single channel and single molecule detection identifies subunit composition of STIM1-activated transient receptor potential canonical (TRPC) channels.  

PubMed

Depletion of intracellular calcium ion stores initiates a rapid cascade of events culminating with the activation of the so-called Store-Operated Channels (SOC) at the plasma membrane. Calcium influx via SOC is essential in the initiation of calcium-dependent intracellular signaling and for the refilling of internal calcium stores, ensuring the regeneration of the signaling cascade. In spite of the significance of this evolutionary conserved mechanism, the molecular identity of SOC has been the center of a heated controversy spanning over the last 20 years. Initial studies positioned some members of the transient receptor potential canonical (TRPC) channel superfamily of channels (with the more robust evidence pointing to TRPC1) as a putative SOC. Recent evidence indicates that Stromal Interacting Molecule 1 (STIM1) activates some members from the TRPC family of channels. However, the exact subunit composition of TRPC channels remains undetermined to this date. To identify the subunit composition of STIM1-activated TRPC channels, we developed novel method, which combines single channel electrophysiological measurements based on the patch clamp technique with single molecule fluorescence imaging. We termed this method Single ion Channel Single Molecule Detection technique (SC-SMD). Using SC-SMD method, we have obtained direct evidence of the subunit composition of TRPC channels activated by STIM1. Furthermore, our electrophysiological-imaging SC-SMD method provides evidence at the molecular level of the mechanism by which STIM1 and calmodulin antagonize to modulate TRPC channel activity. PMID:25465892

Asanov, Alexander; Sampieri, Alicia; Moreno, Claudia; Pacheco, Jonathan; Salgado, Alfonso; Sherry, Ryan; Vaca, Luis

2014-10-31

69

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

70

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

71

An Investigation of the Ability to Recover from Transients Following Failures for Single-Pilot Rotorcraft  

NASA Technical Reports Server (NTRS)

A moving-base simulation was conducted to investigate a pilot's ability to recover from transients following single-axis hard-over failures of the flight-control system. The investigation was performed in conjunction with a host simulation that examined the influence of control modes on a single pilot's ability to perform various mission elements under high-workload conditions. The NASA Ames large-amplitude-motion Vertical Motion Simulator (VMS) was utilized, and the experimental variables were the failure axis, the severity of the failure, and the airspeed at which the failure occurred. Other factors, such as pilot workload and terrain and obstacle proximity at the time of failure, were kept as constant as possible within the framework of the host simulation task scenarios. No explicit failure warnings were presented to the pilot. Data from the experiment are shown, and pilot ratings are compared with the proposed handling-qualities requirements for military rotorcraft. Results indicate that the current proposed failure transient requirements may need revision.

Mansur, M. Hossein; Schroeder, Jeffery A.

1988-01-01

72

Characterization of the mechanisms affecting single-event transients in sub-100 nm technologies  

NASA Astrophysics Data System (ADS)

This dissertation uses both three-dimensional mixed-mode technology-computer-aided design (TCAD) simulations and experimental analysis at the 65 nm, 90 nm, and 130 nm technology nodes to fully characterize the mechanisms that affect single-event transient (SETs) in sub-100 nm bulk CMOS technologies. Chapter I introduces the motivation for this work. Chapter II presents background on single-event effects. Within the chapter, single-event effects are identified and explained in context to digital circuits. Chapter III then focuses on the specific single-event effect of SETs and the factors that influence them. In the second part of the chapter, the discussion focuses on common methods of experimental SET measurement and the typical target structures used. Chapter IV discusses the relationship between the parasitic bipolar and n-well contacts, and how it affects the pulse width of SETs. Chapter V then introduces the mechanism of pulse quenching by using TCAD simulations, heavy-ion data, and laser data, to identify pulse quenching in multiple technology nodes. Additionally the chapter explains in detail how the layout and circuit design can influence pulse quenching. Finally, Chapter VI presents simulation and experimental heavy-ion results that explain a new SET mechanism called DPSETs. Instead of a single ion strike creating a single pulse SET, a single ion strike can result in a DPSET. The research presented in this dissertation directly impacts the SEE circuit qualification and analysis techniques used in the radiation effects community. Simulations supported by experimental data illustrate how there are new mechanisms in sub-100 nm bulk CMOS that can affect SET pulse widths. These mechanisms can negate traditional RHBD solutions, but also can be used as new RHBD solutions. Designers and researchers can use this work to better analyze SET results, and they can predict how SET pulse width will be affected in future bulk CMOS technologies. (Abstract shortened by UMI.)

Ahlbin, Jonathan Ragnar

73

BWR/6 startup and transient tests at Grand Gulf Nuclear Station: Final report  

SciTech Connect

This report documents the results of four plant tests performed during the Grand Gulf Nuclear Station Unit 1 startup test program. The report provides a source of first-of-a-kind BWR/6 data and an interpretation of the major data trends. The data may be applied in the qualification of reactor simulation computer codes. The transient data were recorded through the use of a General Electric Transient Analysis Recording System (GETARS). The detailed data trends are provided in Part I of the proprietary version of this report (2nd tier). Part II of the 2nd tier (proprietary) report entitled, ''Reactor Design Data for Grand Gulf Nuclear Station Unit 1,'' provides the reactor design data which can be used for the construction of a computer model to simulate the transients reported herein. The actual data are available from Electric Power Research Institute. 5 refs., 1 fig., 11 tabs.

Bhandari, B.J.; Crouch, W.D.; Nir, I.; Peng, S.J.; Rao, D.; Sanjines, L.F.; Alesil, G.; Nourse, R.D.

1989-03-01

74

Electronically controlled mechanical seal for aerospace applications--Part 2: Transient tests  

NASA Astrophysics Data System (ADS)

An electronically controlled mechanical seal for use as the purge gas seal in a liquid oxygen turbopump has been fabricated and tested under transient operating conditions. The thickness of the lubricating film is controlled by adjusting the coning of the carbon face. This is accomplished by applying a voltage to a piezoelectric actuator to which the carbon face is bonded. The seal has been operated with a closed-loop control system that utilizes either the leakage rate or seal face temperature as the feedback. Both speed and pressure transients have been imposed on the seal. The transient tests have demonstrated that the seal is capable of maintaing low leakage rates while limiting face temperatures.

Wolff, Paul J.; Salant, Richard F.

1995-01-01

75

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

76

Estimation of pulsed laser-induced single event transient in a partially depleted silicon-on-insulator 0.18-?m MOSFET  

NASA Astrophysics Data System (ADS)

In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal—oxide—semiconductor (MOS) devices irradiated by pulsed laser beams. Transient signal characteristics of a 0.18-?m single MOS device, such as SET pulse width, pulse maximum, and collected charge, are measured and analyzed at wafer level. We analyze in detail the influences of supply voltage and pulse energy on the SET characteristics of the device under test (DUT). The dependences of SET characteristics on drain-induced barrier lowering (DIBL) and the parasitic bipolar junction transistor (PBJT) are also discussed. These results provide a guide for radiation-hardened deep sub-micrometer PDSOI technology for space electronics applications.

Bi, Jin-Shun; Zeng, Chuan-Bin; Gao, Lin-Chun; Liu, Gang; Luo, Jia-Jun; Han, Zheng-Sheng

2014-08-01

77

Transient Lift-off Test Results for an Experimental Hybrid Bearing in Air  

E-print Network

A hybrid bearing designed for use in a next generation turbo-pump is evaluated for the performance of initial lift-off, referred to as start-transient. The radial test rig features a high-speed spindle motor capable of 20,000 rpm that drives a 718...

Klooster, David

2011-02-22

78

Testing and Lubrication for Single Race Bearings  

SciTech Connect

Three ES and H-compatible lubricants (Environment, Safety and Health) for single race bearing applications and one hybrid-material single race bearings were evaluated and compared against single race bearings with trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon), which is an ozone-depleting solvent. Vydax has been used as a bearing lubricant in stronglink mechanisms since 1974. Hybrid bearings with silicon nitride balls and molded glass-nylon-Teflon retainers, bearings lubricated with titanium carbide (TiC) on the balls, bearings lubricated with sputtered MoS{sub 2} on races and retainers, and bearings lubricated with electrophoretically deposited MoS{sub 2} were evaluated. The bearings were maintained in a preloaded state in bearing cartridges during cycling and vibration tests. Bearings with electrophoretically deposited MoS{sub 2} performed as well as bearings lubricated with Vydax and were the best performing candidate. All candidates were suitable for low preload applications. Bearings with TiC coated balls and bearings lubricated with sputtered MoS{sub 2} on the races and retainers performed well at high preloads, though not as well as bearings lubricated with electrophoretic deposition of MoS{sub 2}. Bearings with silicon nitride balls were not suitable for high preload applications.

Steinhoff, R.G.

1998-03-04

79

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 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...

2012-10-01

80

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

81

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 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...

2010-10-01

82

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

83

Method of Generating Transient Equivalent Sink and Test Target Temperatures for Swift BAT  

NASA Technical Reports Server (NTRS)

The NASA Swift mission has a 600-km altitude and a 22 degrees maximum inclination. The sun angle varies from 45 degrees to 180 degrees in normal operation. As a result, environmental heat fluxes absorbed by the Burst Alert Telescope (BAT) radiator and loop heat pipe (LHP) compensation chambers (CCs) vary transiently. Therefore the equivalent sink temperatures for the radiator and CCs varies transiently. In thermal performance verification testing in vacuum, the radiator and CCs radiated heat to sink targets. This paper presents an analytical technique for generating orbit transient equivalent sink temperatures and a technique for generating transient sink target temperatures for the radiator and LHP CCs. Using these techniques, transient target temperatures for the radiator and LHP CCs were generated for three thermal environmental cases: worst hot case, worst cold case, and cooldown and warmup between worst hot case in sunlight and worst cold case in the eclipse, and three different heat transport values: 128 W, 255 W, and 382 W. The 128 W case assumed that the two LHPs transport 255 W equally to the radiator. The 255 W case assumed that one LHP fails so that the remaining LHP transports all the waste heat from the detector array to the radiator. The 382 W case assumed that one LHP fails so that the remaining LHP transports all the waste heat from the detector array to the radiator, and has a 50% design margin. All these transient target temperatures were successfully implemented in the engineering test unit (ETU) LHP and flight LHP thermal performance verification tests in vacuum.

Choi, Michael K.

2004-01-01

84

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

85

NONLINEAR OPTICS: Spontaneous oscillations, single pulses, and transient processes in multistage interferometers with competing nonlinearities  

NASA Astrophysics Data System (ADS)

A numerical investigation was made of a mathematical model describing the dynamics of a semiconductor Fabry-Perot interferometer with competing carrier-density and thermal mechanisms of nonlinear refraction and with absorption that increases on increase in temperature. The first-ever investigations were made of the following topics: spontaneous oscillations of the transmission near various equilibrium conditions and switching from one limit cycle to another; generation of single pulses in response to weak additional illumination in the case of a monostable optical multivibrator; nonmonotonic transient processes during switching. The proposed model made it possible to study the transition of a dispersive optical bistability to spontaneous oscillations and then to an absorptive bistability (breakdown) as a result of variation of the parameters of the system.

Grigor'yants, A. V.; Rzhanov, Yu A.; Balkare?, Yu I.; Elinson, M. I.

1987-10-01

86

Test of the hypothesis of transient molten state diffusion for swift-heavy-ion induced mixing  

SciTech Connect

The recently proposed hypothesis that swift-heavy-ion induced mixing is a consequence of a transient molten state diffusion is tested by studying 230 MeV Au ion induced mixing at an Fe/Si interface monitored online by elastic recoil detection analysis. An extensive data analysis has been made to determine the experimental intrinsic diffusivities of Fe in Si, and vice versa. The required size and duration of the transient melt phase have been calculated theoretically from the thermal spike model. The close resemblance of the experimental diffusivities to the liquid state diffusivities reported in the literature is a verification of the hypothesis.

Srivastava, S.K. [Nuclear Science Centre, Aruna Asaf Ali Marg, P. O. Box 10502, New Delhi 110067 (India); Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse-3, 70569 Stuttgart (Germany); Avasthi, D.K. [Nuclear Science Centre, Aruna Asaf Ali Marg, P. O. Box 10502, New Delhi 110067 (India); Assmann, W. [Sektion Physik, Universitaet Muenchen, D-85748 Garching (Germany); Wang, Z.G. [Centre Interdisciplinaire de Recherches avec les Ions Lourds, Laboratoire mixte CEA-CNRS, rue Claude Bloch, Boite Postale 5133, 14040 Caen Cedex (France); Kucal, H.; Jacquet, E.; Toulemonde, M. [Centre Interdisciplinaire de Recherches Ion Laser, CIRIL, Boite Postale 5133, F-14070 Caen Cedex 5 (France); Carstanjen, H.D. [Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse-3, 70569 Stuttgart (Germany)

2005-05-15

87

Transient getter scheme for the Tokamak Fusion Test Reactor  

SciTech Connect

The ability of the Tokamak Fusion Test Reactor (TFTR) to attain the largest fusion power gain depends critically on minimizing plasma contamination and controlling the densities of the reacting deuterium and tritium. Experiments on a number of tokamaks have demonstrated that gettering over an appreciable surface area (greater than or equal to 10%) of the vacuum vessel greatly facilitates both of these objectives. One particular problem in implementing a surface pumping system in TFTR, however, is a restriction on the maximum allowable tritium content of the getter. This restriction could require regeneration of the absorbed tritium after as few as 50 machine pulses. We have developed a scheme utilizing SAES Zr/Al getter modules which obviates the need for such frequent interruptions of machine operation by taking advantage of the pulsed operation of TFTR. With the Zr/Al getter at temperatures between 500/sup 0/C to 600/sup 0/C it is possible to achieve a quasi-steady state in the tritium loading where the quantity of tritium desorbed between pulses is equal to the quantity which is absorbed during a pulse. Since frequent thermal cycling is not required, this scheme also reduces the possibility of Zr/Al getter material fatigue.

Cecchi, J.L.; Cohen, S.A.; Sredniawski, J.J.

1980-01-01

88

Transient Analytic Element Solutions for Flexible Aquifer Test Analyses  

NASA Astrophysics Data System (ADS)

We present three extensions to the 2D Laplace transform analytic element method (LT-AEM), introduced by Furman and Neuman (2003), which exemplify the types of problems that are easily solved using the LT-AEM, and are useful for performing flexible aquifer test analyses. First, we give the equation for a simplified leaky aquifer- aquitard LT-AEM system, similar to that used by Hantush (1960); in this example the source term is proportional to the drawdown in the aquifer (dual-domain flow is another example). Secondly, we present an approximate unconfined integrodifferential equation, as initially proposed by Boulton (1954) and generalized by Herrera, et al (1978). This solution illustrates how problems defined by convolution integrals are easily handled using LT-AEM (leaky systems can also be represented using convolution integrals). Finally, we present a damped-wave generalization of the diffusion equation that arises from considering a more general form of Darcy's law. The effects of inertia in the aquifer can be considered and may be important near sources in very course materials (e.g., gravel packed envelopes surrounding pumping wells). This final example shows how higher-order time derivatives may be handled in a simple and elegant fashion using LT-AEM techniques; solving the wave equation is as straightforward as solving the diffusion equation in Laplace space. Each of the LT-AEM problems presented here can be solved using any developed LT-AEM element (e.g., point, line, or area sources) or any combination of them, with little modification to the method used to solve the standard diffusion equation.

Kuhlman, K. L.; Neuman, S. P.

2007-12-01

89

Application of a novel test system to characterize single-event effects at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

Details of a customized cryogenic test system for use in in situ single-event radiation tests on semiconductor devices at cryogenic temperatures are presented. The lightweight portable system is designed for performing heavy-ion broadbeam single-event radiation testing at different beam facilities. It is designed for use with either liquid nitrogen or liquid helium as cryogens, depending on the desired lower temperature limit. A controlled heating system on the inside allows for single-event radiation tests as a function of temperature. To enable single-event strikes at angles, the device under test can be rotated about a vertical axis without having to break vacuum. Electrical connectivity to the device under test is provided through six fully customizable hermetically sealed connecting ports. The system has been used to conduct single-event tests over temperature on a test circuit fabricated in IBM CMOS 130 nm technology. Single-event transient pulse widths were found to increase by up to 30% as the temperature was varied from -135 °C to +20 °C. Device simulations indicate that single-event-induced parasitic bipolar transistor turn-on in the n-well of PMOS transistors is responsible for the observed increase in pulse widths across the temperature ranges considered.

Ramachandran, Vishwanath; Gadlage, Matthew J.; Ahlbin, Jonathan R.; Narasimham, Balaji; Alles, Michael L.; Reed, Robert A.; Bhuva, Bharat L.; Massengill, Lloyd W.; Black, Jeffrey D.; Foster, Christopher N.

2010-10-01

90

Microscale material testing of single crystalline silicon  

NASA Astrophysics Data System (ADS)

The mechanical properties of single crystalline silicon (SCS) in microscale are characterized using a uniaxial tension test. The samples are prepared using, various micromachining techniques. The dimensions of the tension specimen at the maximum stress region are 5 to 10 mum in thickness and 20 to 100 mum in width. The sample has two illumination marks on the top surface for strain measurement. The uniaxial tension test setup has been built to accommodate requirements such as sample handling, sample alignment, and friction elimination. Stress is measured using a commercial load cell. Strain is measured by laser interferometry. All the components are connected to a data acquisition board and controlled by a personal computer. Measured Young's moduli in three directions agree well with the reference values and verify the reliability of the setup and measurement procedure. The measured fracture strength is 0.6 GPa to 1.2 GPa, depending on sample preparation methods and loading directions. Preliminary work for fracture toughness measurements using a sharp initial crack is also presented. Future works include further investigation of fracture surfaces, fracture toughness measurement using crack opening criteria, and improvement of the testing apparatus.

Yi, Taechung

91

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

SciTech Connect

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 a dipole flow pattern in the aquifer by pumping water at a constant rate from the aquifer into one chamber, transferring it within the well to the next chamber, and finally injecting it back to the aquifer. A mathematical model describing the drawdown in each chamber is derived for the transient as well as the steady state cases. The aquifer parameters may be estimated from data produced by the dipole flow test alone or in conjunction with conventional pumping tests. The dipole flow regime reaches a steady state relatively quickly, especially in well permeable aquifers. A robust computational methodology for estimating the aquifer parameters, suitable for automatization, is based on the Newton-Raphson algorithm applied to a system of up to three nonlinear equations, each describing the well drawdown at a different judiciously chosen time. Due to the relatively small drawdown it invokes, the dipole flow test may be applicable to unconfined aquifers as well.

Kabala, Z.J. (Univ. of California, Riverside (United States))

1993-01-01

92

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

93

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

94

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

95

49 CFR 238.311 - Single car test.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 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...

2012-10-01

96

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

97

April 24, 2001 Radiation Tests for Single Event Effects  

E-print Network

April 24, 2001 Radiation Tests for Single Event Effects for the ATLAS Tile Calorimeter Front End-mail: Richard.Teuscher@cern.ch, spano@hep.uchicago.edu Proton irradiation tests for single event effects card, and the ADC integrator card. 1 Objective This note describes proton irradiation tests for single

98

49 CFR 238.311 - Single car test.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

99

49 CFR 238.311 - Single car test.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 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...

2010-10-01

100

Optical fiber-based single-shot picosecond transient absorption spectroscopy  

NASA Astrophysics Data System (ADS)

A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving ˜15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into a sample where it is overlapped with an electron pulse or laser excitation pulse, followed by imaging onto a charge coupled device (CCD) detector where the intensity of light from each fiber is measured simultaneously. Application to both ultrafast pump-probe spectroscopy and pulse radiolysis is demonstrated. For pulse radiolysis, the prototype bundle provides the ability to collect data with a time resolution limited only by the electron pulse width of 7-10 ps, over a total single-shot time window of ˜1.5 ns. Tunable probe light is obtained from a titanium-sapphire laser and an optical parametric amplifier. Corrections are made to remove the fiber-to-fiber variations in signal magnitude due to the spatial overlap of the electron beam and probe image. High quality data can be collected over most of the sensitivity range of the CCD camera detectors. The single-shot instrument is valuable for measurement of samples that are only available in very limited quantities, are too viscous to flow, or are rigid. It is therefore excellent in applications, such as picosecond pulse radiolysis, where the thousands of pulses per kinetic trace typical in classical pump-probe experiments can damage the sample before useful results could be obtained.

Cook, Andrew R.; Shen, Yuzhen

2009-07-01

101

Optical fiber-based single-shot picosecond transient absorption spectroscopy.  

PubMed

A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving approximately 15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into a sample where it is overlapped with an electron pulse or laser excitation pulse, followed by imaging onto a charge coupled device (CCD) detector where the intensity of light from each fiber is measured simultaneously. Application to both ultrafast pump-probe spectroscopy and pulse radiolysis is demonstrated. For pulse radiolysis, the prototype bundle provides the ability to collect data with a time resolution limited only by the electron pulse width of 7-10 ps, over a total single-shot time window of approximately 1.5 ns. Tunable probe light is obtained from a titanium-sapphire laser and an optical parametric amplifier. Corrections are made to remove the fiber-to-fiber variations in signal magnitude due to the spatial overlap of the electron beam and probe image. High quality data can be collected over most of the sensitivity range of the CCD camera detectors. The single-shot instrument is valuable for measurement of samples that are only available in very limited quantities, are too viscous to flow, or are rigid. It is therefore excellent in applications, such as picosecond pulse radiolysis, where the thousands of pulses per kinetic trace typical in classical pump-probe experiments can damage the sample before useful results could be obtained. PMID:19655942

Cook, Andrew R; Shen, Yuzhen

2009-07-01

102

THEORETICAL ANALYSIS OF THE TRANSIENT PRESSURE RESPONSE FROM A CONSTANT FLOW RATE HYDRAULIC CONDUCTIVITY TEST.  

USGS Publications Warehouse

Incorporating a flow pump into a conventional triaxial laboratory system allows fluid to be supplied to or withdrawn from the base of a sediment sample at small and constant rates. An initial transient record of hydraulic head versus time is observed which eventually stabilizes to a constant steady state gradient across the sample; values of hydraulic conductivity can subsequently be determined from Darcy's law. In this paper, analytical methods are presented for determining values of specific storage and hydraulic conductivity from the initial transient phase of such a constant flow rate test. These methods are based on a diffusion equation involving pore pressure and are analogous to those used to describe the soil consolidation process and also to interpret aquifer properties from pumping tests.

Morin, Roger H.; Olsen, Harold W.

1987-01-01

103

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

104

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

105

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

106

Estimation of AOFP and average reservoir pressure from transient flow-after-flow test data: A reservoir management practice  

SciTech Connect

A method for analyzing transient flow-after-flow (FAF) deliverability test data from both gas and oil wells is presented. The paper describes the derivation and application of this method to several field and synthetic cases. The method solves the transient absolute open flow potential (AOFP) and average reservoir pressure ({bar p}) by evaluating the parameters of the Forchheimer (a and b) and the empirical backpressure (C and n) equations together with {bar p}. Consequently, this new method allows one to describe the stabilized deliverability equation from transient test data, given reasonable estimates of the reservoir drainage area and shape. All the resulting formulations are flexible enough to handle the pressure, pressure-squared, and pseudopressure approach for gas wells. This methodology is not restricted to gas wells as oil wells also lend themselves to the proposed analysis procedures. For oil wells, the authors used the pressure approach for single-phase flow and the pressure-squared approach for two-phase flow. In the proposed technique, a well`s orientation is unimportant. For example, a horizontal well`s deliverability may also be characterized using the new method. In addition, layered reservoirs may be analyzed with the proposed technique. They also show that this method can be extended to injection wells. Synthetic data were initially used to verify the method. Field data from several gas and oil wells, including a horizontal well and gas injector, were then used to demonstrate the method`s application. In all cases, the new method shows good agreement with the results obtained from conventional methods, both in terms of AOFP and {bar p}.

Kabir, C.S.; King, G.R.

1995-12-31

107

Quantifying Transient 3D Dynamical Phenomena of Single mRNA Particles in Live Yeast Cell Measurements  

PubMed Central

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 4ms), 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 over-interpreted (the tools are applicable to linear or nonlinear SDEs calibrated from non-stationary 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.

2013-01-01

108

Testing fluvial erosion models using the transient response of bedrock rivers to tectonic forcing in the Apennines, Italy  

E-print Network

Testing fluvial erosion models using the transient response of bedrock rivers to tectonic forcing fluvial erosion models. However, some recent studies of bedrock erosion conclude that transient river long profiles can be approximately characterized by a transportlimited erosion model, while other authors

Cowie, Patience

109

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

110

Numerical simulation and experimental study of transient liquid phase bonding of single crystal superalloys  

NASA Astrophysics Data System (ADS)

The primary goals of the research in this dissertation are to perform a systematic study to identify and understand the fundamental cause of prolonged processing time during transient liquid phase bonding of difficult-to-bond single crystal Ni-base materials, and use the acquired knowledge to develop an effective way to reduce the isothermal solidification time without sacrificing the single crystalline nature of the base materials. To achieve these objectives, a multi-scale numerical modeling approach, that involves the use of a 2-D fully implicit moving-mesh Finite Element method and a Cellular Automata method, was developed to theoretically investigate the cause of long isothermal solidification times and determine a viable way to minimize the problem. Subsequently, the predictions of the theoretical models are experimentally validated. Contrary to previous suggestions, numerical calculations and experimental verifications have shown that enhanced intergranular diffusivity has a negligible effect on solidification time in cast superalloys and that another important factor must be responsible. In addition, it was found that the concept of competition between solute diffusivity and solubility as predicted by standard analytical TLP bonding models and reported in the literature as a possible cause of long solidification times is not suitable to explain salient experimental observations. In contrast, however, this study shows that the problem of long solidification times, which anomalously increase with temperature is fundamentally caused by departure from diffusion controlled parabolic migration of the liquid-solid interface with holding time during bonding due to a significant reduction in the solute concentration gradient in the base material. Theoretical analyses showed it is possible to minimize the solidification time and prevent formation of stray-grains in joints between single crystal substrates by using a composite powder mixture of brazing alloy and base alloy as the interlayer material, which prior to the present work has been reported to be unsuitable. This was experimentally verified and the use of the composite powder mixture as interlayer material to reduce the solidification time and avoid stray-grain formation during TLP bonding of single crystal superalloys has been reported for the first time in this research.

Ghoneim, Adam

111

Testing the ontogenetic base for the transient model of inflorescence development  

PubMed Central

Backgrounds and Aims Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the ‘transient model’ successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called ‘vegetativeness’ (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development. Methods To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inflorescences was investigated under scanning electron microscopy. Early and late inflorescence meristems were measured and compared during inflorescence development in 13 eudicot species from 11 families. Key Results The initial size of the inflorescence meristem in closed inflorescences correlates with the number of nodes in the mature inflorescence. Conjunct compound inflorescences (panicles) show a constant decrease of meristematic size from early to late inflorescence meristems, while disjunct compound inflorescences present an enlargement by merging from early inflorescence meristems to late inflorescence meristems, implying a qualitative change of the apical meristems during ontogeny. Conclusions Partial confirmation was found for the transient model for inflorescence architecture in the ontogeny: the initial size of the apical meristem in closed inflorescences is consistent with the postulated veg decline mechanism regulating the size of the inflorescence. However, the observed biphasic kinetics of the development of the apical meristem in compound racemes offers the primary explanation for their disjunct morphology, contrary to the putative exclusive transient mechanism in lateral axes as expected by the model. PMID:23425784

Bull-Hereñu, Kester; Claßen-Bockhoff, Regine

2013-01-01

112

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. IE-34, NO. 3, AUGUST 1987 Transient Tests on a Voltage-Regulated  

E-print Network

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. IE-34, NO. 3, AUGUST 1987 _~~~~~~ Transient Tests electronics revolution becomes more pervasive, the harmonic content will become more and more intolerable

Catholic University of Chile (Universidad Católica de Chile)

113

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. PMID:24748694

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

114

A multiscale method for subsurface inverse modeling: Single-phase transient flow  

NASA Astrophysics Data System (ADS)

High-resolution geologic models that incorporate observed state data are expected to effectively enhance the reliability of reservoir performance prediction. One of the major challenges faced is how to solve the large-scale inverse modeling problem, i.e., to infer high-resolution models from the given observations of state variables that are related to the model parameters according to some known physical rules, e.g., the flow and transport partial differential equations. There are typically two difficulties, one is the high-dimensional problem and the other is the inverse problem. A multiscale inverse method is presented in this work to attack these problems with the aid of a gradient-based optimization algorithm. In this method, the model responses (i.e., the simulated state data) can be efficiently computed from the high-resolution model using the multiscale finite-volume method. The mismatch between the observations and the multiscale solutions is then used to define a proper objective function, and the fine-scale sensitivity coefficients (i.e., the derivatives of the objective function with respect to each node's attribute) are computed by a multiscale adjoint method for subsequent optimization. The difficult high-dimensional optimization problem is reduced to a one-dimensional one using the gradient-based gradual deformation method. A synthetic single-phase transient flow example problem is employed to illustrate the proposed method. Results demonstrate that the multiscale framework presented is not only computationally efficient but also can generate geologically consistent models. By preserving spatial structure for inverse modeling, the method presented overcomes the artifacts introduced by the multiscale simulation and may enhance the prediction ability of the inverse-conditional realizations generated.

Fu, Jianlin; Caers, Jef; Tchelepi, Hamdi A.

2011-08-01

115

COMMIX1A: a three-dimensional transient single-phase computer program for thermal hydraulic analysis of single and multicomponent systems. Volume I: users manual  

Microsoft Academic Search

The COMMIX-1A computer program is an updated and improved version of COMMIX-1 designed to analyze steady-state\\/transient, single-phase, three-dimensional fluid flow with heat transfer in reactor components and multicomponent systems. A new porous-media formulation via local volume averaging has been derived and employed in the COMMIX code. The concepts of volume porosity, directional surface permeability, distributed resistance, and distributed heat source

H. M. Domanus; R. C. Schmitt; W. T. Sha; V. L. Shah

1983-01-01

116

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

117

Power of Single- vs. Multi-Marker Tests of Association  

PubMed Central

Current genome-wide association studies still heavily rely on a single-marker strategy, in which each single nucleotide polymorphism (SNP) is tested individually for association with a phenotype. Although methods and software packages that consider multimarker models have become available, they have been slow to become widely adopted and their efficacy in real data analysis is often questioned. Based on conducting extensive simulations, here we endeavor to provide more insights into the performance of simple multimarker association tests as compared to single-marker tests. The results reveal the power advantage as well as disadvantage of the two- vs. the single-marker test. Power differentials depend on the correlation structure among tag SNPs, as well as that between tag SNPs and causal variants. A two-marker test has relatively better performance than single-marker tests when the correlation of the two adjacent markers is high. However, using HapMap data, two-marker tests tended to have a greater chance of being less powerful than single-marker tests, due to constraints on the number of actual possible haplotypes in the HapMap data. Yet, the average power difference was small whenever the one-marker test is more powerful, while there were many situations where the two-marker test can be much more powerful. These findings can be useful to guide analyses of future studies. PMID:22648939

Wang, Xuefeng; Morris, Nathan J.; Schaid, Daniel J.; Elston, Robert C.

2013-01-01

118

Theoretical Evaluation of the Transient Response of Constant Head and Constant Flow-Rate Permeability Tests  

USGS Publications Warehouse

A theoretical analysis is presented that compares the response characteristics of the constant head and the constant flowrate (flow pump) laboratory techniques for quantifying the hydraulic properties of geologic materials having permeabilities less than 10-10 m/s. Rigorous analytical solutions that describe the transient distributions of hydraulic gradient within a specimen are developed, and equations are derived for each method. Expressions simulating the inflow and outflow rates across the specimen boundaries during a constant-head permeability test are also presented. These solutions illustrate the advantages and disadvantages of each method, including insights into measurement accuracy and the validity of using Darcy's law under certain conditions. The resulting observations offer practical considerations in the selection of an appropriate laboratory test method for the reliable measurement of permeability in low-permeability geologic materials.

Zhang, M.; Takahashi, M.; Morin, R.H.; Esaki, T.

1998-01-01

119

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

120

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

121

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

122

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

123

Transient elastography improves detection of liver cirrhosis compared to routine screening tests  

PubMed Central

AIM: To investigate the diagnostic significance of transient elastography (TE) in a daily routine clinical setting in comparison to clinical signs, laboratory parameters and ultrasound. METHODS: TE, ultrasound, laboratory parameters and cutaneous liver signs were assessed in 291 consecutive patients with chronic liver disease of various aetiologies who underwent liver biopsy in daily routine. RESULTS: Sensitivity of TE for the detection of liver cirrhosis was 90.4%, compared to 80.1% for ultrasound, 58.0% for platelet count and 45.1% for cutaneous liver signs (P < 0.0001 for comparisons with histology). AUROC for TE was 0.760 (95%CI: 0.694-0.825). Combination of TE with ultrasound increased sensitivity to 96.1% and AUROC to 0.825 (95%CI: 0.768-0.882). TE correlated with laboratory parameters of cirrhosis progression like albumin (r = -0.43), prothrombin time (r = -0.44), and bilirubin (r = 0.34; P < 0.001 for each). Particularly, in patients with Child Pugh score A or normal platelet count TE improved sensitivity for the detection of liver cirrhosis compared to ultrasound by 14.1% (P < 0.04) and 16.3% (P < 0.02), respectively. CONCLUSION: Transient elastography is superior to routine diagnostic tests allowing detection of liver cirrhosis in additional 10%-16% of patients with chronic liver disease that would have been missed by clinical examinations.

Göbel, Thomas; Schadewaldt-Tümmers, Janine; Greiner, Lucas; Poremba, Christopher; Häussinger, Dieter; Erhardt, Andreas

2015-01-01

124

Carrier Dynamics in a-Fe2O3 (0001) Thin Films and Single Crystals Probed by Femtosecond Transient Absorption and Reflectivity  

SciTech Connect

Femtosecond transient reflectivity and absorption is used to measure the carrier lifetimes in ?-Fe2O3 thin films and hematite single crystals. The results from the thin films show that initially excited hot electrons relax to the bandedge within 300 femtoseconds and then recombine with holes or trap within 5 pioseconds. The trapped electrons have a lifetime of hundreds of picoseconds. The trapped electrons have a lifetime of hundreds of picoseconds. Transient reflectivity measurements from hematite (?-Fe2O3) single crystals show similar but slightly faster dynamics. In hematite, the transient reflectivity displays oscillations due to the formation of longitudinal acoustic phonons generated following absorption of the ultrashort excitation pulse.

Joly, Alan G.; Williams, Josh R.; Chambers, Scott A.; Xiong, Gang; Hess, Wayne P.; Laman, David M.

2006-03-01

125

Deep level transient spectroscopy studies of n-type ZnO single crystals grown by different techniques.  

PubMed

In the present study single-crystalline ZnO samples grown from the vapor phase, the melt, and a high-temperature aqueous solution (hydrothermal growth) are investigated before and after hydrogen plasma treatments, by means of deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS. Dominant DLTS peaks are found to appear in the range of 120-350 K for all materials. The DLTS spectra depend on the procedure of growth of the ZnO. The thermal stabilities of the defects in an oxygen atmosphere and in an oxygen-lean atmosphere are analyzed. The origin of the DLTS peaks is discussed. PMID:21813951

Scheffler, L; Kolkovsky, Vl; Lavrov, E V; Weber, J

2011-08-24

126

Testing of the TWIGL code with a reactivity transient in a large graphite-moderated reactor  

SciTech Connect

As part of the effort to improve multidimensional reactivity transient analysis capability for a large graphite-moderated reactor, the TWIGL code was adapted to the Hanford N Reactor and successfully tested with some recent time- and space-dependent reactor data. The Hanford N Reactor is a large graphite-moderated light-water-cooled reactor operated by UNC Nuclear Industries for the US Dept. of Energy. The reactor is an approx. 10.1- x 10.2- x 12.0-m graphite cuboid penetrated by 1003 horizontal Zircaloy pressure tubes, 84 horizontal control rod penetrations, 107 vertical ball backup safety system channels, 640 graphite cooling tubes parallel to the control rods, and numerous steam vent passages.

Toffer, H.; Twitchell, R.W.; Crowe, R.D.

1987-01-01

127

Measuring the Optical Performance of Evacuated Receivers via an Outdoor Thermal Transient Test: Preprint  

SciTech Connect

Modern parabolic trough solar collectors operated at high temperatures to provide the heat input to Rankine steam power cycles employ evacuated receiver tubes along the collector focal line. High performance is achieved via the use of a selective surface with a high absorptance for incoming short-wave solar radiation and a low emittance for outgoing long-wave infrared radiation, as well as the use of a hard vacuum to essentially eliminate convective and conductive heat losses. This paper describes a new method that determines receiver overall optical efficiency by exposing a fluid-filled, pre-cooled receiver to one sun outdoors and measuring the slope of the temperature curve at the point where the receiver temperature passes the glass envelope temperature (that is, the point at which there is no heat gain or loss from the absorber). This transient test method offers the potential advantages of simplicity, high accuracy, and the use of the actual solar spectrum.

Kutscher, C.; Burkholder, F.; Netter, J.

2011-08-01

128

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

129

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

130

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

SciTech Connect

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 alternatives being evaluated in the environmental assessment. These alternatives are (1) resumption of transient testing using the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) and (2) conducting transient testing using the Annular Core Research Reactor (ACRR) at Sandia National Laboratory in New Mexico (SNL/NM). Analyses are provided for radiologic emissions, other air emissions, soil contamination, and groundwater contamination that could occur (1) during normal operations, (2) as a result of accidents in one of the facilities, and (3) during transport. It does not include an assessment of the biotic, cultural resources, waste generation, or other impacts that could result from the resumption of transient testing. Analyses were conducted by technical professionals at INL and SNL/NM as noted throughout this report. The analyses are based on bounding radionuclide inventories, with the same inventories used for test materials by both alternatives and different inventories for the TREAT Reactor and ACRR. An upper value on the number of tests was assumed, with a test frequency determined by the realistic turn-around times required between experiments. The estimates provided for impacts during normal operations are based on historical emission rates and projected usage rates; therefore, they are bounding. Estimated doses for members of the public, collocated workers, and facility workers that could be incurred as a result of an accident are very conservative. They do not credit safety systems or administrative procedures (such as evacuation plans or use of personal protective equipment) that could be used to limit worker doses. Doses estimated for transportation are conservative and are based on transport of the bounding radiologic inventory that will be contained in any given test. The transportation analysis assumes all transports will contain the bounding inventory.

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

2014-02-01

131

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

132

Effects of drain-wall in mitigating N-hit single event transient via 45 nm CMOS process  

NASA Astrophysics Data System (ADS)

A three-dimensional (3D) technology computer-aided design (TCAD) simulation in a novel layout technique for N-hit single event transient (SET) mitigation based on drain-wall layout technique is proposed. Numerical simulations of both single-device and mixed-mode show that the proposed layout technique designed with 45 nm CMOS process can efficiently reduce not only charge collection but also SET pulse widths (WSET). What is more, simulations show that impacts caused by part of ion-incidents can be shielded with this novel layout technique. When compared with conventional layout technique and guard drain layout technique, we find that the proposed novel layout technique can provide the best benefit of SET mitigation with a small sacrifice in effective area.

Y Xu, X.; Xiong, Y.; Tang, M. H.; Xiao, Y. G.; Yan, S. A.; Zhang, W. L.; Zhao, W.; Guo, H. X.; Li, Z.

2015-01-01

133

Charge-carrier properties in synthetic single-crystal diamond measured with the transient-current technique  

E-print Network

For optimal operation of chemical-vapor deposition (CVD) diamonds as charged particle detectors it is important to have a detailed understanding of the charge-carrier transport mechanism. This includes the determination of electron and hole drift velocities as a function of electric field, charge carrier lifetimes, as well as effective concentration of space charge in the detector bulk. We use the transient-current technique, which allows a direct determination of these parameters in a single measurement, to investigate the charge-carrier properties in a sample of single-crystal CVD diamond. The method is based on the injection of charge using an alpha source close to the surface and measuring the induced current in the detector electrodes as a function of time.

Pernegger, H; Frais-Kölbl, H; Griesmayer, E; Kagan, H; Roe, S; Schnetzer, S; Stone, R; Trischuk, W; Twitchen, D; Weilhammer, Peter; Whitehead, A; 10.1063/1.1863417

2005-01-01

134

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

NASA Astrophysics Data System (ADS)

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.

1988-07-01

135

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

136

Single Event Transient Response of SiGe Voltage References and Its Impact on the Performance of Analog and Mixed-Signal Circuits  

Microsoft Academic Search

We investigate the single-event transient (SET) response of bandgap voltage references (BGRs) implemented in SiGe BiCMOS technology through heavy ion microbeam experiments. The SiGe BGR circuit is used to provide the input reference voltage to a voltage regulator. SiGe HBTs in the BGR circuit are struck with 36-MeV oxygen ions, and the subsequent transient responses are captured at the output

Laleh Najafizadeh; Stanley D. Phillips; Kurt A. Moen; Ryan M. Diestelhorst; Marco Bellini; Prabir K. Saha; John D. Cressler; Gyorgy Vizkelethy; Marek Turowski; Ashok Raman; Paul W. Marshall

2009-01-01

137

Single-file diffusion of particles in a box: transient behaviors.  

PubMed

We consider a finite number of particles with soft-core interactions, subjected to thermal fluctuations and confined in a box with excluded mutual passage. Using numerical simulations, we focus on the influence of the longitudinal confinement on the transient behavior of the longitudinal mean squared displacement. We exhibit several power laws for its time evolution according to the confinement range and to the rank of the particle in the file. We model the fluctuations of the particles as those of a chain of springs and point masses in a thermal bath. Our main conclusion is that actual system dynamics can be described in terms of the normal oscillation modes of this chain. Moreover, we obtain complete expressions for the physical observables, in excellent agreement with our simulations. The correct power laws for the time dependency of the mean squared displacement in the various regimes are recovered, and analytical expressions of the prefactors according to the relevant parameters are given. PMID:23005055

Delfau, Jean-Baptiste; Coste, Christophe; Saint Jean, Michel

2012-06-01

138

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

139

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

140

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

NASA Astrophysics Data System (ADS)

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

141

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. PMID:1382783

Delpón, E.; Tamargo, J.; Sánchez-Chapula, J.

1992-01-01

142

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

143

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

144

A rare variant association test based on combinations of single-variant tests.  

PubMed

Next generation sequencing technologies make direct testing rare variant associations possible. However, the development of powerful statistical methods for rare variant association studies is still underway. Most of existing methods are burden and quadratic tests. Recent studies show that the performance of each of burden and quadratic tests depends strongly upon the underlying assumption and no test demonstrates consistently acceptable power. Thus, combined tests by combining information from the burden and quadratic tests have been proposed recently. However, results from recent studies (including this study) show that there exist tests that can outperform both burden and quadratic tests. In this article, we propose three classes of tests that include tests outperforming both burden and quadratic tests. Then, we propose the optimal combination of single-variant tests (OCST) by combining information from tests of the three classes. We use extensive simulation studies to compare the performance of OCST with that of burden, quadratic and optimal single-variant tests. Our results show that OCST either is the most powerful test or has similar power with the most powerful test. We also compare the performance of OCST with that of the two existing combined tests. Our results show that OCST has better power than the two combined tests. PMID:25065727

Sha, Qiuying; Zhang, Shuanglin

2014-09-01

145

Randomization Regression Tests for Single-Subject Data.  

ERIC Educational Resources Information Center

In a Monte Carlo analysis of single-subject data, Type I and Type II error rates were compared for various statistical tests of the significance of treatment effects. Data for 5,000 subjects in each of 6 treatment effect size groups were computer simulated, and 2 types of treatment effects were simulated in the dependent variable during…

Aaron, Bruce C.; Kromrey, Jeffrey D.

146

Pressure transient test analysis of vuggy naturally fractured carbonate reservoir: field case study  

E-print Network

is to analyze, interpret and categorize the pressure transient responses obtained from 22 wells in a vuggy naturally fractured carbonate reservoir in an attempt to understand the heterogeneities of the porosity system. Different modeling techniques useful...

Ajayi, Babatunde Tolulope

2009-06-02

147

Single event upset testing with relativistic heavy ions  

SciTech Connect

Two bipolar devices, the AMD 2901B microprocessor and the AMD 27LS00 256-bit RAM, have been tested for single event upset using relativistic heavy ions. Upset thresholds and asymptotic cross sections have been measured with iron, argon and neon beams having cosmic ray energies. Further, the magnitude of the funnel effect in the 2901B was determined by irradiating the device at normal incidence and at large angles and comparing the observed upset thresholds. Combinatorial logic upsets were seen in the 2901B and their cross section measured. The 27LS00 exhibited multibit upset produced by single ions penetrating the device edge-on.

Criswell, T.L.; Measeal, P.R.; Walin, K.L.

1984-12-01

148

Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped inverters for disintegratable, transient electronics  

SciTech Connect

This paper presents materials, device designs, and physical/electrical characteristics of a form of nanotube electronics that is physically transient, in the sense that all constituent elements dissolve and/or disperse upon immersion into water. Studies of contact effects illustrate the ability to use water soluble metals such as magnesium for source/drain contacts in nanotube based field effect transistors. High mobilities and on/off ratios in transistors that use molybdenum, silicon nitride, and silicon oxide enable full swing characteristics for inverters at low voltages (?5?V) and with high gains (?30). Dissolution/disintegration tests of such systems on water soluble sheets of polyvinyl alcohol demonstrate physical transience within 30 min.

Jin, Sung Hun, E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu; Shin, Jongmin; Cho, In-Tak; Lee, Jong-Ho, E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu [Department of Electrical and Computer Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Han, Sang Youn [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Display R and D Center, Samsung Display Co., Yongin-city, Gyeongki-do 446–711 (Korea, Republic of); Lee, Dong Joon; Lee, Chi Hwan; Rogers, John A., E-mail: harin74@gmail.com, E-mail: jhl@snu.ac.kr, E-mail: jrogers@illinois.edu [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-07-07

149

Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped inverters for disintegratable, transient electronics  

NASA Astrophysics Data System (ADS)

This paper presents materials, device designs, and physical/electrical characteristics of a form of nanotube electronics that is physically transient, in the sense that all constituent elements dissolve and/or disperse upon immersion into water. Studies of contact effects illustrate the ability to use water soluble metals such as magnesium for source/drain contacts in nanotube based field effect transistors. High mobilities and on/off ratios in transistors that use molybdenum, silicon nitride, and silicon oxide enable full swing characteristics for inverters at low voltages (˜5 V) and with high gains (˜30). Dissolution/disintegration tests of such systems on water soluble sheets of polyvinyl alcohol demonstrate physical transience within 30 min.

Jin, Sung Hun; Shin, Jongmin; Cho, In-Tak; Han, Sang Youn; Lee, Dong Joon; Lee, Chi Hwan; Lee, Jong-Ho; Rogers, John A.

2014-07-01

150

Subjective audiological tests and transient evoked otoacoustic emissions in patients with rheumatoid arthritis: analysis of the factors affecting hearing levels  

Microsoft Academic Search

We investigated hearing functions in patients with rheumatoid arthritis (RA) using audiological tests and transient evoked\\u000a otoacoustic emissions (TEOAEs). The study group consisted of 20 adult patients with RA (7 males, 13 females); 20 adult healthy\\u000a subjects without RA (7 males, 13 females) were recruited as controls. All patients were evaluated by pure tone audiometry,\\u000a high frequency audiometry, tympanometry and

O?uzhan Dikici; Nuray Bayar Muluk; Aliye Kapukiran Tosun; Ihsan Ünlüsoy

2009-01-01

151

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

152

An entropy test for single-locus genetic association analysis  

PubMed Central

Background The etiology of complex diseases is due to the combination of genetic and environmental factors, usually many of them, and each with a small effect. The identification of these small-effect contributing factors is still a demanding task. Clearly, there is a need for more powerful tests of genetic association, and especially for the identification of rare effects Results We introduce a new genetic association test based on symbolic dynamics and symbolic entropy. Using a freely available software, we have applied this entropy test, and a conventional test, to simulated and real datasets, to illustrate the method and estimate type I error and power. We have also compared this new entropy test to the Fisher exact test for assessment of association with low-frequency SNPs. The entropy test is generally more powerful than the conventional test, and can be significantly more powerful when the genotypic test is applied to low allele-frequency markers. We have also shown that both the Fisher and Entropy methods are optimal to test for association with low-frequency SNPs (MAF around 1-5%), and both are conservative for very rare SNPs (MAF<1%) Conclusions We have developed a new, simple, consistent and powerful test to detect genetic association of biallelic/SNP markers in case-control data, by using symbolic dynamics and symbolic entropy as a measure of gene dependence. We also provide a standard asymptotic distribution of this test statistic. Given that the test is based on entropy measures, it avoids smoothed nonparametric estimation. The entropy test is generally as good or even more powerful than the conventional and Fisher tests. Furthermore, the entropy test is more computationally efficient than the Fisher's Exact test, especially for large number of markers. Therefore, this entropy-based test has the advantage of being optimal for most SNPs, regardless of their allele frequency (Minor Allele Frequency (MAF) between 1-50%). This property is quite beneficial, since many researchers tend to discard low allele-frequency SNPs from their analysis. Now they can apply the same statistical test of association to all SNPs in a single analysis., which can be especially helpful to detect rare effects. PMID:20331859

2010-01-01

153

Single element injector testing for STME injector technology  

NASA Technical Reports Server (NTRS)

An oxidizer-swirled coaxial element injector is being developed for application in the liquid oxygen/gaseous hydrogen Space Transportation Main Engine (STME) for the National Launch System (NLS) vehicle. This paper reports on the first two parts of a four part single injector element study for optimization of the STME injector design. Measurements of Rupe mixing efficiency and atomization characteristics are reported for single element versions of injection elements from two multielement injectors that have been recently hot fire tested. Rather than attempting to measure a definitive mixing efficiency or droplet size parameters of these injector elements, the purpose of these experiments was to provide a baseline comparison for evaluating future injector element design modifications. Hence, all the experiments reported here were conducted with cold flow simulants to nonflowing, ambient conditions. Mixing experiments were conducted with liquid/liquid simulants to provide economical trend data. Atomization experiments were conducted with liquid/gas simulants without backpressure. The results, despite significant differences from hot fire conditions, were found to relate to mixing and atomization parameters deduced from the hot fire testing, suggesting that these experiments are valid for trend analyses. Single element and subscale multielement hot fire testing will verify optimized designs before committing to fullscale fabrication.

Hulka, J.; Schneider, J. A.; Davis, J.

1992-01-01

154

Global nuclear energy partnership fuels transient testing at the Sandia National Laboratories nuclear facilities : planning and facility infrastructure options.  

SciTech Connect

The Global Nuclear Energy Partnership fuels development program is currently developing metallic, oxide, and nitride fuel forms as candidate fuels for an Advanced Burner Reactor. The Advance Burner Reactor is being designed to fission actinides efficiently, thereby reducing the long-term storage requirements for spent fuel repositories. Small fuel samples are being fabricated and evaluated with different transuranic loadings and with extensive burnup using the Advanced Test Reactor. During the next several years, numerous fuel samples will be fabricated, evaluated, and tested, with the eventual goal of developing a transmuter fuel database that supports the down selection to the most suitable fuel type. To provide a comparative database of safety margins for the range of potential transmuter fuels, this report describes a plan to conduct a set of early transient tests in the Annular Core Research Reactor at Sandia National Laboratories. The Annular Core Research Reactor is uniquely qualified to perform these types of tests because of its wide range of operating capabilities and large dry central cavity which extents through the center of the core. The goal of the fuels testing program is to demonstrate that the design and fabrication processes are of sufficient quality that the fuel will not fail at its design limit--up to a specified burnup, power density, and operating temperature. Transient testing is required to determine the fuel pin failure thresholds and to demonstrate that adequate fuel failure margins exist during the postulated design basis accidents.

Kelly, John E.; Wright, Steven Alan; Tikare, Veena; MacLean, Heather J. (Idaho National Laboratory, Idaho Falls, ID); Parma, Edward J., Jr.; Peters, Curtis D.; Vernon, Milton E.; Pickard, Paul S.

2007-10-01

155

Measurement of transient acoustic fields using a single-shot pressure-sensitive paint system  

NASA Astrophysics Data System (ADS)

A pressure-sensitive paint (PSP) system capable of measuring high-frequency acoustic fields with non-periodic, acoustic-level pressure changes is described. As an optical measurement technique, PSP provides the experimenter with a global distribution of pressure on a painted surface. To demonstrate frequency response and enhanced sensitivity to pressure changes, a PSP system consisting of a polymer/ceramic matrix binder with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the oxygen probe was applied to a wall inside an acoustic resonance cavity excited at 1.3 kHz. A data acquisition technique based on the luminescent decay lifetime of the oxygen sensors excited by a single pulse of light afforded the ability to capture instantaneous pressure fields with no phase-averaging. Superimposed wave-like structures were observed with a wavelength corresponding to a 4.7% difference from the theoretical value for a sound wave emanating from the speaker. High sound pressure cases upwards of 145 dB (re 20 ?Pa) exhibited skewed nodal lines attributed to a nonlinear acoustic field. The lowest sound pressure level of 125.4 dB—corresponding to an amplitude of 52.7 Pa, or approximately 0.05% of standard sea-level atmospheric pressure—showed that the paint could resolve the spatial details of the mode shape at the given resonance condition.

Disotell, Kevin J.; Gregory, James W.

2011-07-01

156

Measurement of transient acoustic fields using a single-shot pressure-sensitive paint system.  

PubMed

A pressure-sensitive paint (PSP) system capable of measuring high-frequency acoustic fields with non-periodic, acoustic-level pressure changes is described. As an optical measurement technique, PSP provides the experimenter with a global distribution of pressure on a painted surface. To demonstrate frequency response and enhanced sensitivity to pressure changes, a PSP system consisting of a polymer?ceramic matrix binder with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the oxygen probe was applied to a wall inside an acoustic resonance cavity excited at 1.3 kHz. A data acquisition technique based on the luminescent decay lifetime of the oxygen sensors excited by a single pulse of light afforded the ability to capture instantaneous pressure fields with no phase-averaging. Superimposed wave-like structures were observed with a wavelength corresponding to a 4.7% difference from the theoretical value for a sound wave emanating from the speaker. High sound pressure cases upwards of 145 dB (re 20 ?Pa) exhibited skewed nodal lines attributed to a nonlinear acoustic field. The lowest sound pressure level of 125.4 dB--corresponding to an amplitude of 52.7 Pa, or approximately 0.05% of standard sea-level atmospheric pressure--showed that the paint could resolve the spatial details of the mode shape at the given resonance condition. PMID:21806232

Disotell, Kevin J; Gregory, James W

2011-07-01

157

Use of panel tests in place of single gene tests in the cancer genetics clinic.  

PubMed

Improved technology has made it possible to test for mutations within multiple genes simultaneously. It is not clear when these gene 'panels' should be used in the hereditary cancer setting. These analyses were intended to guide panel testing criteria. Offering hereditary panel testing as a first and final, 'single-tier', option was explored. A 'two-tiered' approach, in which panel testing is offered reflexively following stricter criteria, was then applied to the same data. Within our cohort of 105 patients, the single-tier approach was associated with a higher mutation detection rate (6.7% vs 3.8%) and variant of uncertain significance (VUS) rate (0.94 vs 0.23 average per person) compared to a two-tiered approach. Of the VUSs also identified in other patients by another lab, 53% were classified differently between laboratories. Individuals reporting African American race had more VUSs compared to other ancestry groups (p?=?0.001). The test cost for a single-tier test was 21% more than a two-tiered approach. Single-tier panel testing was associated with higher mutation and VUS rates, and there is inconsistent classification of the VUS/low penetrant genes between laboratories. PMID:25318351

Yorczyk, A; Robinson, L S; Ross, T S

2014-10-16

158

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); Colella, Nicholas John (Livermore, CA)

1997-01-01

159

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

160

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

161

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

162

Pump and probe damage testing for investigation of transient material modifications associated with laser damage in optical materials  

SciTech Connect

Laser-induced breakdown in the bulk of transparent dielectric materials is associated with the generation of extreme localized conditions of temperatures and pressures. In this work, we perform pump and probe damage testing experiments to investigate the evolution of transient absorption by the host material arising from modifications following confined laser energy deposition in fused silica and DKDP materials. Specifically, we measure the size of the damage sites observed in the region of spatial overlap between the pump and probe pulses versus probe time delay and energy. Results of this proof-of-principle experimental work confirm that material modifications under extreme conditions created during a damage event include transient optical absorption. In addition, we found that the relaxation times of the induced absorption are very distinct for DKDP and SiO{sub 2} even under identical excitation conditions, on the order of 100 ns and 100 {micro}s, respectively.

Negres, R A; Feit, M D; DeMange, P; Bude, J D; Demos, S G

2007-10-18

163

Cultural Resource Investigations for the Resumption of Transient Testing of Nuclear Fuels and Material at the Idaho National Laboratory  

SciTech Connect

The U. S. Department of Energy (DOE) has a need to test nuclear fuels under conditions that subject them to short bursts of intense, high-power radiation called ‘transient testing’ in order to gain important information necessary for licensing new nuclear fuels for use in U.S. nuclear power plants, for developing information to help improve current nuclear power plant performance and sustainability, for improving the affordability of new generation reactors, for developing recyclable nuclear fuels, and for developing fuels that inhibit any repurposing into nuclear weapons. To meet this mission need, DOE is considering alternatives for re-use and modification of existing nuclear reactor facilities to support a renewed transient testing program. One alternative under consideration involves restarting the Transient Reactor Test (TREAT) reactor located at the Materials and Fuels Complex (MFC) on the Idaho National Laboratory (INL) site in southeastern Idaho. This report summarizes cultural resource investigations conducted by the INL Cultural Resource Management Office in 2013 to support environmental review of activities associated with restarting the TREAT reactor at the INL. These investigations were completed in order to identify and assess the significance of cultural resources within areas of potential effect associated with the proposed action and determine if the TREAT alternative would affect significant cultural resources or historic properties that are eligible for nomination to the National Register of Historic Places. No archaeological resources were identified in the direct area of potential effects for the project, but four of the buildings proposed for modifications are evaluated as historic properties, potentially eligible for nomination to the National Register of Historic Places. This includes the TREAT reactor (building #), control building (building #), guardhouse (building #), and warehouse (building #). The proposed re-use of these historic properties is consistent with original missions related to nuclear reactor testing and is expected to result in no adverse effects to their historic significance. Cultural resource investigations also involved communication with representatives from the Shoshone-Bannock Tribes to characterize cultural resources of potential tribal concern. This report provides a summary of the cultural resources inventoried and assessed within the defined areas of potential effect for the resumption of transient testing at the INL. Based on these analyses, proposed activities would have no adverse effects on historic properties within the APEs that have been defined. Other archaeological resources and cultural resources of potential concern to the Shoshone-Bannock Tribes and others that are located near the APEs are also discussed with regard to potential indirect impacts. The report concludes with general recommendations for measures to reduce impacts to all identified resources.

Brenda R. Pace; Julie B. Williams

2013-11-01

164

Constitutive modeling of superalloy single crystals with verification testing  

NASA Technical Reports Server (NTRS)

The goal is the development of constitutive equations to describe the elevated temperature stress-strain behavior of single crystal turbine blade alloys. The program includes both the development of a suitable model and verification of the model through elevated temperature-torsion testing. A constitutive model is derived from postulated constitutive behavior on individual crystallographic slip systems. The behavior of the entire single crystal is then arrived at by summing up the slip on all the operative crystallographic slip systems. This type of formulation has a number of important advantages, including the prediction orientation dependence and the ability to directly represent the constitutive behavior in terms which metallurgists use in describing the micromechanisms. Here, the model is briefly described, followed by the experimental set-up and some experimental findings to date.

Jordan, Eric; Walker, Kevin P.

1985-01-01

165

Axisymmetric granular collapse: a transient 3D flow test of viscoplasticity.  

PubMed

A viscoplastic continuum theory has recently been proposed to model dense, cohesionless granular flows [P. Jop, Nature (London) 441, 727 (2006)10.1038/nature04801]. We confront this theory for the first time with a transient, three-dimensional flow situation--the simple collapse of a cylinder of granular matter onto a horizontal plane--by extracting stress and strain rate tensors directly from soft particle simulations. These simulations faithfully reproduce the different flow regimes and capture the observed scaling laws for the final deposit. Remarkably, the theoretical hypothesis that there is a simple stress-strain rate tensorial relationship does seem to hold across the whole flow even close to the rough boundary provided the flow is dense enough. These encouraging results suggest viscoplastic theory is more generally applicable to transient, multidirectional, dense flows and open the way for quantitative predictions in real applications. PMID:19392169

Lacaze, Laurent; Kerswell, Rich R

2009-03-13

166

Single-pass rub testing of abradable seal materials  

NASA Technical Reports Server (NTRS)

A pendulum-type test device has been built for use in studying rubs between a turbine or compressor blade tip or labyrinth seal knife edge and specimens of abradable gas path seal materials. The device allows measurement of the rub energy dissipated in a single wear event, along with friction and normal forces and wear. Subsequent rubs over the same surface can also be monitored, with microscopic observation of the rub surface being possible after any of the passes. The device was used in tests of several potential abradable materials, ranging from porous to fully dense. It was shown that the rub energy dissipated in initial and subsequent passes is a fundamental parameter in the evaluation of material abradability. Rub energy was found to be influenced by such factors as: density and tensile (or yield) strength of the abradable material, prior densification or work hardening of the rub surface, and the sharpness of the leading edge of the blade tip.

Kennedy, F. E.; Hine, N. P.

1981-01-01

167

Single event test methodology and test results of commercial gigabit per second fiber channel hardware  

SciTech Connect

This article presents a detailed description of the single event test methods used to evaluate two different component sets conforming to the Fiber Channel (FC) commercial high-speed serial bus standard. The devices tested perform the hierarchically low-level functions such as transmission coding and actual electrical or optical linking. Pertinent portions of the FC specification, and details of the test setup and methods are presented prior to description of the observed error types, correlation of error types to source circuitry, and radiation test results. The authors conclude that one of these COTS device sets may be suitable for space use with the use of additional circuit hardening, and that the other (also a COTS device set) is not suitable for space use. The test methods and descriptions of error types should prove useful in preparation for future FC component SEE testing.

Carts, M.A.; Marshall, P.W. [Naval Research Lab., Washington, DC (United States)] [Naval Research Lab., Washington, DC (United States); [SFA, Inc., Largo, MD (United States); Marshall, C.J. [Naval Research Lab., Washington, DC (United States)] [Naval Research Lab., Washington, DC (United States); Label, K.A.; Flanegan, M.; Bretthauer, J. [NASA GSFC, Greenbelt, MD (United States)] [NASA GSFC, Greenbelt, MD (United States)

1997-12-01

168

New modelling of transient well test and rate decline analysis for a horizontal well in a multiple-zone reservoir  

NASA Astrophysics Data System (ADS)

The no-type curve with negative skin of a horizontal well has been found in the current research. Negative skin is very significant to transient well test and rate decline analysis. This paper first presents the negative skin problem where the type curves with negative skin of a horizontal well are oscillatory. In order to solve the problem, we propose a new model of transient well test and rate decline analysis for a horizontal well in a multiple-zone composite reservoir. A new dimensionless definition of rD is introduced in the dimensionless mathematical modelling under different boundaries. The model is solved using the Laplace transform and separation of variables techniques. In Laplace space, the solutions for both constant rate production and constant wellbore pressure production are expressed in a unified formula. We provide graphs and thorough analysis of the new standard type curves for both well test and rate decline analysis; the characteristics of type curves are the reflections of horizontal well production in a multiple-zone reservoir. An important contribution of our paper is that our model removed the oscillation in type curves and thus solved the negative skin problem. We also show that the characteristics of type curves depend heavily on the properties of different zones, skin factor, well length, formation thickness, etc. Our research can be applied to a real case study.

Nie, Ren-Shi; Guo, Jian-Chun; Jia, Yong-Lu; Zhu, Shui-Qiao; Rao, Zheng; Zhang, Chun-Guang

2011-09-01

169

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

170

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

Code of Federal Regulations, 2012 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...

2012-10-01

171

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

Code of Federal Regulations, 2010 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...

2010-10-01

172

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

Code of Federal Regulations, 2011 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...

2011-10-01

173

78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures  

Federal Register 2010, 2011, 2012, 2013

...FRA-2013-0064] Petition for Modification of Single Car Air Brake Test Procedures In accordance...per 49 CFR 232.307 to modify the single car air brake test procedures located in AAR...System Tests for Freight Equipment-- Single Car Test, and required pursuant to 49 CFR...

2013-07-23

174

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

175

Minimized transient and steady-state cross regulation in 55nm CMOS single-inductor dual-output (SIDO) step-down DC-DC converter  

Microsoft Academic Search

A single-inductor dual-output (SIDO) step-down converter with continuous conduction mode (CCM) control is proposed for high efficiency system-on-a-chip (Soc) integration. The cross regulation in steady-state output voltage ripple, which is rarely mentioned, is effectively reduced as well as in transient response. The low-voltage energy distribution controller (LV-EDC) circuit guarantees good voltage regulation and low output voltage ripple simultaneously. In addition,

Yu-Huei Lee; Tzu-Chi Huang; Yao-Yi Yang; Ke-Horng Chen; Ying-Hsi Lin; Wen-Shen Chou; Chen-Chih Huang; Yi-Kuang Chen

2010-01-01

176

Transient thermal analysis of PWR’s by a single-pass procedure using a simplified nodal layout  

E-print Network

PWR accident conditions and analysis methods have been reviewed. Limitations of the simplified method with respect to analysis of these accident conditions are drawn and two transients ( loss of coolant flow, seized rotor) ...

Liu, Jack S. H.

1979-01-01

177

Transient improvement of poststroke apathy with zolpidem: a single-case, placebo-controlled double-blind study  

PubMed Central

We report the case of a 44-year-old patient with severe and disabling apathy nearly 2?years after a right hemisphere haemorrhagic stroke. The effect of a single dose of zolpidem was tested over a 2-week period, in alternation with either no treatment or a placebo in a double-blind randomised trial. Zolpidem was associated with a dramatic improvement in apathy, as assessed with the Apathy Inventory and the Behavioral Dysexecutive Syndrome Inventory. No adverse effect occurred during the trial. PMID:23396925

Autret, Katell; Arnould, Annabelle; Mathieu, Sarah; Azouvi, Philippe

2013-01-01

178

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

179

Single Stage Contactor Testing Of The Next Generation Solvent Blend  

SciTech Connect

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

2014-01-06

180

Test of Single-Stage Axial-Flow Fan  

NASA Technical Reports Server (NTRS)

A single-stage axial fan was built and tested in the shop of the propeller-research tunnel of the NACA. The fan comprised a simple 24-blade rotor having a diameter of 21 inches and a solidity of 0.86 and a set of 37 contravanes having a solidity of 1.33. The rotor was driven by a 25-horsepower motor capable of rotating at a speed of 3600 r.p.m. The fan was tested for volume, pressure, and efficiency over a range of delivery pressures and volumes for a wide range of contravane and blade-angle settings. The test results are presented in chart form in terms of nondimensional units in order that similar fans may be accurately designed with a minimum effort. The maximum efficiency (88 percent) was obtained by the fan at a blade angle of 30 degrees and a contravane angle of 70 degrees. An efficiency of 80 percent was obtained by the fan with the contravanes removed.

Bell, E Barton

1942-01-01

181

Title: Single Probe Traversal Approach Testing of MCM Substrate Interconnections  

E-print Network

constitute a major fraction production cost due expensive commercial flyi. Keywords: Flying Probe Testing, MCM Substrate Test, Test Time Optimization, TSP, Probabilistic Analysis. Index Terms: Flying probe testing, MCM substrate test, Test time optimization, TSP, Probabilistic

Tovey, Craig A.

182

Results of MPBX studies at the single heater test  

SciTech Connect

We have developed an extensometer for measurement of distance and displacements in a geologic repository for high-level nuclear waste. This is an optical extensometer that measures distance using a modulated laser beam. In this design, reflecting targets are placed at desired measurement locations, and distance between each target and an optical head are measured repeatedly using the modulated laser beam. Moreover, all electronic and moving parts are located outside of the hostile or difficult environment as the optical head is connected to the laser, switching and signal analysis hardware using optical fibers. A reference beam is utilized to provide direct correction of system behavior. `Be system also - utilizes movable reflective anchors that can be repositioned if desired. We have installed the system in the Single Heater Test being conducted in Alcove 5 of the Exploratory Studies Facility at Yucca Mountain, and report preliminary results.

Blair, S. C.,LLNL

1997-10-01

183

Testing the single degenerate channel for supernova Ia  

NASA Astrophysics Data System (ADS)

The progenitors of supernova Ia are close binaries containing white dwarfs. Of crucial importance to the evolution of these systems is how much material the white dwarf can stably accrete and hence grow in mass. This occurs during a short-lived intense phase of mass transfer known as the super soft source (SSS) phase. The short duration of this phase and large extinction to soft X-rays means that only a handful are known in our Galaxy. Far more can be learned from the underlying SSS progenitor population of close white dwarf plus FGK type binaries. Unfortunately, these systems are hard to find since the main-sequence stars completely outshine the white dwarfs at optical wavelengths. Because of this, there are currently no known close white dwarf binaries with F, G or early K type companions, making it impossible to determine the contribution of the single degenerate channel towards supernova Ia. Using the GALEX and RAVE surveys we have now identified the first large sample of FGK stars with UV excesses, a fraction of which are these illusive, close systems. Following an intense ground based spectroscopic investigation of these systems, we have identified 5 definite close binaries, with periods of less than a few days. Here we apply for COS spectroscopic observations to measure the mass and temperature of the white dwarfs in order to determine the future evolution of these systems. This will provide a crucial test for the single degenerate channel towards supernova Ia.

Parsons, Steven

2014-10-01

184

Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions  

NASA Astrophysics Data System (ADS)

A study on the sources of variability in the measurement of particle size distribution using a two-stage dilution system and an engine exhaust particle sizer was conducted to obtain a comprehensive and repeatable methodology that can be used to measure the particle size distribution of aerosols emitted by a light-duty diesel engine under transient operating conditions. The paper includes three experimental phases: an experimental validation of the measurement method; an evaluation of the influence of sampling factors, such as dilution system pre-conditioning; and a study of the effects of the dilution conditions, such as the dilution ratio and the dilution air temperature. An examination of the type and degree of influence of each studied factor is presented, recommendations for reducing variability are given and critical parameter values are identified to develop a highly reliable measurement methodology that could be applied to further studies on the effect of engine operating parameters on exhaust particle size distributions.

María Desantes, José; Bermúdez, Vicente; Molina, Santiago; Linares, Waldemar G.

2011-11-01

185

Implementation and Testing of the First Prompt Search for Gravitational Wave Transients with Electromagnetic Counterparts  

NASA Technical Reports Server (NTRS)

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 MilkyWay 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.

Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Agathos, M.; Ajith, P.; Allen, B.; Allen, G. S.; Ceron, E. Amador; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Araya, M. C.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Blackburn, L.

2012-01-01

186

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

NASA Technical Reports Server (NTRS)

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.

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.; Blackburn, L.; Camp, J. B.; Cannizzo, J.; Gehrels, N.

2011-01-01

187

Extended transient-midterm stability package: Test case manual: Computer code manual  

SciTech Connect

Testing programs conducted by six utilities show this analysis package to be a useful tool for assessing power system stability following major disturbances. This report describes the use of the package with four test systems and includes sample outputs.

Not Available

1987-01-01

188

Radiation tests for a single-GEM-loaded gaseous detector  

NASA Astrophysics Data System (ADS)

We report on a systematic study of a single-gas-electron-multiplier (GEM)-loaded gaseous detector developed for precision measurements of high-energy particle beams and for dose verification in particle therapy. In the present study, a 256-channel prototype detector having an active area of 16 × 16 cm2 and operating using a continuous current-integration-mode signal-processing method was manufactured and tested with X-rays emitted from a 70-kV X-ray generator and 43-MeV protons provided by the MC50 proton cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS). The amplified detector response was measured for X-rays with an intensity of about 5 × 106 Hz cm-2. The linearity of the detector response to the particle flux was examined and validated by using 43-MeV proton beams. The non-uniform development of the amplification for the gas electrons in space was corrected by applying a proper calibration to the channel responses of the measured beam-profile data. We conclude from the radiation tests that the detector developed in the present study will allow us to perform quality measurements of various high-energy particle beams and to apply the technology to dose-verification measurements in particle therapy.

Lee, Kyong Sei; Hong, Byungsik; Park, Sung Keun; Kim, Sang Yeol

2014-11-01

189

M3B2 and M5B3 Formation in Diffusion-Affected Zone During Transient Liquid Phase Bonding Single-Crystal Superalloys  

NASA Astrophysics Data System (ADS)

Precipitates in the diffusion-affected zone (DAZ) during transient liquid phase bonding (TLP) single-crystal superalloys were observed and investigated. Small size and dendritic-shaped precipitates were identified to be M3B2 borides and intergrowth of M3B2/M5B3 borides. The orientation relationships among M3B2, M5B3, and matrix were determined using transmission electron microscope (TEM). Composition characteristics of these borides were also analyzed by TEM energy-dispersive spectrometer. Because this precipitating phenomenon deviates from the traditional parabolic transient liquid phase bonding model which assumed a precipitates free DAZ during TLP bonding, some correlations between the deviation of the isothermal solidification kinetics and these newly observed precipitating behaviors were discussed and rationalized when bonding the interlayer containing the high diffusivity melting point depressant elements and substrates of low solubility.

Sheng, Naicheng; Hu, Xiaobing; Liu, Jide; Jin, Tao; Sun, Xiaofeng; Hu, Zhuangqi

2015-01-01

190

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

191

Testing of the single-element stretched-membrane dish  

NASA Astrophysics Data System (ADS)

The goal of the Stretched-Membrane Dish Program is the development of a dish solar concentrator fabricated with a single optical element capable of collecting 60 kWt. Solar Kinetics, Inc., has constructed a prototype 7-meter dish to demonstrate the manufacturability and optical performance of this innovative design. The reflective surface of the dish consists of a plastically deformed metal membrane with a separate reflective polymer membrane on top, both held in place by a low-level vacuum. Sandia conducted a test program to determine the on-sum performance of the dish. The vacuum setting was varied 8.9- to 17. 2-cm of water column and the vertex to target distance was varied over a range of 15.24 cm to evaluate beam quality. The optimal setting for the vacuum was 11.4 centimeters of water column with the best beam quality of 6.4 centimeters behind the theoretical focal point of the dish. Flux arrays based on slope error from the CIRCE2 computer code were compared to the measured flux array of the dish. The uniformly distributed slope error of 2.3 milliradians was determined as the value that would produce a modeled array with the minimum mean square difference to the measured array. Cold water calorimetry measured a power of 23.3 (plus minus) .3 kWt. Reflectivity changed from an initial value of 88.3 percent to 76.7 percent over a one year period.

Grossman, J. W.; Houser, R. M.; Erdman, W. W.

1992-02-01

192

Radiation Tests for a Single-GEM Loaded Gaseous Detector  

E-print Network

We report on the systematic study of a single-gas-electron-multiplication (GEM) loaded gaseous detector developed for precision measurements of high-energy particle beams and dose-verification measurements. In the present study, a 256-channel prototype detector with an active area of 16$\\times$16 cm$^{2}$, operated in a continuous current-integration-mode signal-processing method, was manufactured and tested with x rays emitted from a 70-kV x-ray generator and 43-MeV protons provided by the MC50 proton cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS). The amplified detector response was measured for the x rays with an intensity of about 5$\\times$10$^{6}$ Hz cm$^{-2}$. The linearity of the detector response to the particle flux was examined and validated by using 43-MeV proton beams. The non-uniform development of the amplification for the gas electrons in space was corrected by applying proper calibration to the channel responses of the measured beam-profile data. We concluded fro...

Lee, Kyong Sei; Kim, Sang Yeol; Park, Sung Keun

2014-01-01

193

Electro-optic modulator based gate transient suppression for sine-wave gated InGaAs/InP single photon avalanche photodiode  

NASA Astrophysics Data System (ADS)

Capacitive gate transient noise has been problematic for the high-speed single photon avalanche photodiode (SPAD), especially when the operating frequency extends to the gigahertz level. We proposed an electro-optic modulator based gate transient noise suppression method for sine-wave gated InGaAs/InP SPAD. With the modulator, gate transient is up-converted to its higher-order harmonics that can be easily removed by low pass filtering. The proposed method enables online tuning of the operating rate without modification of the hardware setup. At 250 K, detection efficiency of 14.7% was obtained with 4.8×10-6 per gate dark count and 3.6% after-pulse probabilities for 1550-nm optical signal under 1-GHz gating frequency. Experimental results have shown that the performance of the detector can be maintained within a designated frequency range from 0.97 to 1.03 GHz, which is quite suitable for practical high-speed SPAD applications operated around the gigahertz level.

Zhang, Yixin; Zhang, Xuping; Shi, Yuanlei; Ying, Zhoufeng; Wang, Shun

2014-06-01

194

Numerical and field tests of hydraulic transients at Piva power plant  

NASA Astrophysics Data System (ADS)

In 2009, a sophisticated field investigation was undertaken and later, in 2011, numerical tests were completed, on all three turbine units at the Piva hydroelectric power plant. These tests were made in order to assist in making decisions about the necessary scope of the reconstruction and modernisation of the Piva hydroelectric power plant, a plant originally constructed in the mid-1970s. More specifically, the investigation included several hydraulic conditions including both the start-up and stopping of each unit, load rejection under governor control from different initial powers, as well as emergency shut-down. Numerical results were obtained using the method of characteristics in a representation that included the full flow system and the characteristics of each associated Francis turbine. The impact of load rejection and emergency shut-down on the penstock pressure and turbine speed changes are reported and numerical and experimental results are compared, showing close agreement.

Giljen, Z.

2014-12-01

195

Transient left ventricular dysfunction in ischaemic myocardium after stress: comparative study with exercise and pharmacological stress gated myocardial single photon emission computed tomography.  

PubMed

In ischaemic heart disease patients, transient left ventricular dysfunction is observed due to post-exercise stunning. The aim of this study was to determine whether transient left ventricular dysfunction could also be seen after short-acting pharmacological stress (adenosine triphosphate). A 1 day rest/stress gated myocardial single photon emission computed tomography was performed on 362 patients suspected of having ischaemic heart disease by exercise (n=199) or short-acting pharmacological stress (n=163). Left ventricular ejection fraction were estimated both at rest and stress. Based on perfusion findings, patients were subdivided into ischaemia, fixed defect and normal group. For the ischaemia and fixed defect group, left ventricular ejection fraction after stress was significantly decreased compared with the resting value by exercise stress (ischaemia group, 57.5+/-11.0 vs 60.4+/-10.4; fixed defect group, 47.7+/-16.7 vs 49.6+/-16.8; P<0.01), but not by pharmacological stress (ischaemia group, 55.8+/-13.4 vs 57.1+/-13.8; fixed defect group, 50.8+/-13.5 vs 50.6+/-13.1; P=NS). In the normal group, left ventricular ejection fraction after stress was not significantly changed by either exercise (65.7+/-10.4 vs 66.8+/-10.2; P=NS) or pharmacological stress (63.0+/-11.7 vs 64.0+/-12.1; P=NS). It is concluded that a transient decrease in left ventricular ejection fraction after stress was observed following post-exercise, not following a short-acting pharmacological stress in patients showing perfusion abnormalities. Transient left ventricular dysfunction may be the result of post-exercise stunning, not from subendocardial hypoperfusion induced by short-acting pharmacological stress. PMID:12717073

Iwado, Y; Furuyama, H; Yoshinaga, K; Mabuchi, M; Ito, Y; Noriyasu, K; Kohya, T; Kitabatake, A; Tsukamoto, E; Tamaki, N

2003-05-01

196

Single event effect testing of the Intel 80386 family and the 80486 microprocessor  

SciTech Connect

The authors present single event effect test results for the Intel 80386 microprocessor, the 80387 coprocessor, the 82380 peripheral device, and on the 80486 microprocessor. Both single event upset and latchup conditions were monitored.

Moran, A.; LaBel, K.; Gates, M. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States); Seidleck, C. [Hughes ST Systems, Greenbelt, MD (United States)] [Hughes ST Systems, Greenbelt, MD (United States); McGraw, R. [Jackson and Tull, Greenbelt, MD (United States)] [Jackson and Tull, Greenbelt, MD (United States); Broida, M.; Firer, J. [Daedalian Systems Corp., Greenbelt, MD (United States)] [Daedalian Systems Corp., Greenbelt, MD (United States); Sprehn, S. [Lystad Ltd., Crownsville, MD (United States)] [Lystad Ltd., Crownsville, MD (United States)

1996-06-01

197

Acoustic Data Processing and Transient Signal Analysis for the Hybrid Wing Body 14- by 22-Foot Subsonic Wind Tunnel Test  

NASA Technical Reports Server (NTRS)

An advanced vehicle concept, the HWB N2A-EXTE aircraft design, was tested in NASA Langley's 14- by 22-Foot Subsonic Wind Tunnel to study its acoustic characteristics for var- ious propulsion system installation and airframe con gurations. A signi cant upgrade to existing data processing systems was implemented, with a focus on portability and a re- duction in turnaround time. These requirements were met by updating codes originally written for a cluster environment and transferring them to a local workstation while en- abling GPU computing. Post-test, additional processing of the time series was required to remove transient hydrodynamic gusts from some of the microphone time series. A novel automated procedure was developed to analyze and reject contaminated blocks of data, under the assumption that the desired acoustic signal of interest was a band-limited sta- tionary random process, and of lower variance than the hydrodynamic contamination. The procedure is shown to successfully identify and remove contaminated blocks of data and retain the desired acoustic signal. Additional corrections to the data, mainly background subtraction, shear layer refraction calculations, atmospheric attenuation and microphone directivity corrections, were all necessary for initial analysis and noise assessments. These were implemented for the post-processing of spectral data, and are shown to behave as expected.

Bahr, Christopher J.; Brooks, Thomas F.; Humphreys, William M.; Spalt, Taylor B.; Stead, Daniel J.

2014-01-01

198

Photo-Induced Current Transient Spectroscopy of Semi-insulating Single Crystal Cs2Hg6S7  

NASA Astrophysics Data System (ADS)

The ternary compound Cs2Hg6S7 has shown considerable promise as a wide gap semiconductor for hard radiation detection at room temperature. We report on the measurement of defect levels in Cs2Hg6S7 using photo-induced current transient spectroscopy. We observe a series of defect levels with mean activation energies of 0.053, 0.052, 0.34, 0.35, and 0.46 eV. The defects are attributed to Cs vacancies and Cs and Hg antisite defects. Defect capture cross-sections are in the range 10-20-10-15 cm2.

Liu, Z.; Peters, J. A.; Li, H.; Kanatzidis, M. G.; Im, J.; Jin, H.; Freeman, A. J.; Wessels, B. W.

2015-01-01

199

The diagnostic odds ratio: a single indicator of test performance  

Microsoft Academic Search

Diagnostic testing can be used to discriminate subjects with a target disorder from subjects without it. Several indicators of diagnostic performance have been proposed, such as sensitivity and specificity. Using paired indicators can be a disadvantage in comparing the performance of competing tests, especially if one test does not outperform the other on both indicators. Here we propose the use

Afina S. Glas; Jeroen G. Lijmer; Martin H. Prins; Gouke J. Bonsel; Patrick M. M. Bossuyt

2003-01-01

200

Results of the ETV-1 breadboard tests under steady-state and transient conditions. [conducted in the NASA-LeRC Road Load Simulator  

NASA Technical Reports Server (NTRS)

Steady state tests were run to characterize the system and component efficiencies over the complete speed-torque capabilities of the propulsion system in both motoring and regenerative modes of operation. The steady state data were obtained using a battery simulator to separate the effects on efficiency caused by changing battery state-of-charge and component temperature. Transient tests were performed to determine the energy profiles of the propulsion system operating over the SAE J227a driving schedules.

Sargent, N. B.; Dustin, M. O.

1981-01-01

201

[Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion.  

PubMed

A 63-year-old male patient with a history of stent implantation in the left anterior descending three months before. Due to the presentation of vegetative symptoms, he was referred for gated-SPECT myocardial perfusion. During acquisition of the resting images he presented chest pain and ST segment elevation, so that urgent cardiac catheterization was performed, showing stent thrombosis. Rest perfusion imaging showed a defect in anterior and apical perfusion, more severe and extensive than in the stress images, with striking left ventricular dilatation and a fall in the ejection fraction related to the acute ischemia phenomenon. Intense exercise is associated with a transient activation of the coagulation system and hemodynamic changes that might induce thrombosis, especially in recently implanted coronary stents that probably still have not become completely endothelialized. PMID:25129322

Miranda, B; Pizzi, M N; Aguadé-Bruix, S; Domingo, E; Candell-Riera, J

2014-08-13

202

Methods of testing for a deficit in single-case studies: Evaluation of statistical power by  

E-print Network

Methods of testing for a deficit in single-case studies: Evaluation of statistical power by Monte to controls is a fundamental feature of many neuropsychological single-case studies. Monte Carlo simulation has been used in a number of single-case studies for the same purpose (see Bobes et al., 2004; Farrer

Crawford, John R.

203

ORNL rod-bundle heat-transfer test data. Volume 2. Thermal-Hydraulic Test Facility experimental data report for test 3. 03. 6AR - transient film boiling in upflow  

SciTech Connect

Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) Test 3.03.6AR. This test was conducted by members of the ORNL Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer (BDHT) Separate-Effects Program on May 21, 1980. Objective was to investigate heat transfer phenomena believed to occur in PWRs during accidents, including small and large break loss-of-coolant accidents. Test 3.03.6AR was conducted to obtain transient film boiling data in rod bundle geometry under reactor accident-type conditions. The primary purpose of this report is to make the reduced instrument responses for THTF Test 3.03.6AR available. Included in the report are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers.

Mullins, C. B.; Felde, D. K.; Sutton, A. G.; Gould, S. S.; Morris, D. G.; Robinson, J. J.

1982-04-01

204

ORNL rod-bundle heat-transfer test data. Volume 3. Thermal-hydraulic test facility experimental data report for test 3. 06. 6B - transient film boiling in upflow. [PWR  

SciTech Connect

Reduced instrument responses are presented for Thermal-Hyraulic Test Facility (THTF) Test 3.06.6B. This test was conducted by members of the Oak Ridge National Laboratory Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer (BDHT) Separate-Effects Program on August 29, 1980. The objective of the program was to investigate heat transfer phenomena believed to occur in PWR's during accidents, including small and large break loss-of-coolant accidents. Test 3.06.6B was conducted to obtain transient film boiling data in rod bundle geometry under reactor accident-type conditions. The primary purpose of this report is to make the reduced instrument responses for THTF Test 3.06.6B available. Included in the report are uncertainties in the instrument responses, calculated mass flows, and calculated rod powers.

Mullins, C.B.; Felde, D.K.; Sutton, A.G.; Gould, S.S.; Morris, D.G.; Robinson, J.J.

1982-05-01

205

76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures  

Federal Register 2010, 2011, 2012, 2013

...FRA-2010-0174] Petition for Modification of Single Car Air Brake Test Procedures In accordance...FRA) grant a modification of the single car air brake test procedures as prescribed...FRA-2010-0174. PATH operates a fleet of 25 flat cars in consist with revenue cars utilized...

2011-06-14

206

Single-stranded DNA as a recombination substrate in plants as assessed by stable and transient recombination assays.  

PubMed Central

Two separate assays, one that requires stable integration of recombination products and one that does not, were employed to elucidate the role of single-stranded DNA in extrachromosomal homologous recombination in Nicotiana tabacum. Both assays revealed that single-stranded DNA in linear and in circular forms was an efficient substrate for recombination, provided that the cotransformed recombination substrates were of complementary sequence, so that direct annealing was possible. Recombination was inefficient when both single-stranded recombination partners contained homologous regions of identical sequence and generation of a double-stranded DNA was required prior to heteroduplex formation. These results indicate that direct annealing of single strands is an important initial step for intermolecular recombination in tobacco cells. Annealed cotransformed single-stranded molecules yielded intermediates that could be further processed by either continuous or discontinuous second-strand synthesis. The type of intermediate had no influence on the recombination efficiency. Double-stranded circles were unable to recombine efficiently either with each other or with single-stranded DNA. Our results suggest that a helicase activity is involved in the initial steps of double-stranded DNA recombination which unwinds duplex molecules at the site of double-strand breaks. Images PMID:1729608

Bilang, R; Peterhans, A; Bogucki, A; Paszkowski, J

1992-01-01

207

Fabrication and Test of Ferromagnetic Single-Electron-Transistors  

E-print Network

with a micropositioning XYZ sample stage. The test system is computer controlled using Labview programming environment . . . . . . . . . . . . . . . . . . . 1 1.2 Task and Motivation of the Diploma Project . . . . . . . . . . . 2 1.3 Structure of the Report

Haviland, David

208

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

209

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

210

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

211

Development of a qualified nodalization for small-break LOCA transient analysis in PSB-VVER integral test facility by RELAP5 system code  

Microsoft Academic Search

This paper deals with development and qualification of a nodalization for modeling of the PSB-VVER integral test facility (ITF) by RELAP5\\/MOD3.2 code and prediction of its primary and secondary systems behaviors at steady state and transient conditions. The PSB-VVER is a full-height, 1\\/300 volume and power scale representation of a VVER-1000 NPP. A RELAP5 nodalization has been developed for PSB-VVER

S. Shahedi; J. Jafari; M. Boroushaki; F. D’Auria

2010-01-01

212

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

213

Simulating single cell experiments in mechanical testing of adipocytes.  

PubMed

This study introduces new three-dimensional finite element cell modeling for simulating the structural, large deformation behavior of maturing adipocytes, based on empirically acquired geometrical properties of cultured adipocyte cells. We created models of adipocyte differentiation and maturation, which represented four stages along that process. The modeling focused on two specific and commonly used experimental setups, one involving compression of individual adipocytes and the other stretching of adipocytes. Both are physiological loading regimes for fat tissues and cells in vivo, and both are often employed for testing cell responses to deformations in the context of obesity and pressure ulcer research. In both simulation types, and in all the cell models, external loads induced localized effective Lagrange strains in the plasma membrane that reached maximum values over the lipid droplets (LDs). We also observed that the effective stresses (averaged across the entire cell volume in each model case) increased with cell maturation and varied between cells with different structure and dimensions. This result points to an increase in the effective cell stiffness with maturation, which would have been expected, since the volume of the stiffer LDs increases as adipocytes mature. Overall, the mechanical behavior of an individual cell is influenced not only by the external mechanical loads that are exerted, but also by the cell structure and dimensions, and is fundamental to any interpretation of cell mechanics experiments, and particularly for testing adipocytes. PMID:25212098

Katzengold, Rona; Shoham, Naama; Benayahu, Dafna; Gefen, Amit

2014-09-12

214

Transient Behaviour of Batch Arrival Queue with N-Policy and Single Vacation (Mx/G/1/N-POLICY)  

NASA Astrophysics Data System (ADS)

In this paper Mx/G/1 queuing system with N-policy and single vacation is considered. As soon as the system becomes empty, the server leaves the system for a vacation of random length V. When he returns from the vacation, if the system size is greater then or equal to predetermined value N (threshold), he begins to serve the customers. If not, the server waits in the system until the system size reaches or exceeds N. Here the time dependent system size distribution is obtained.

Solanki, Anjana

2009-07-01

215

Direct comparison of charge collection from single-photon and two-photon laser testing techniques.  

SciTech Connect

The amounts of charge collection by single-photon absorption to that by two-photon absorption laser testing techniques have been directly compared using specially made SOI diodes. Details of this comparison are discussed.

Ferlet-Cavrois, Veronique (ESA/ESTEC); Dalton, Scott Matthew; Stevens, Jeffrey; Flores, Richard S.; Gouker, Pascale M. (MIT Lincoln Laboratory); Schwank, James Ralph; McMorrow, Dale (Naval Research Laboratory); Swanson, Scot E.; Shaneyfelt, Marty Ray; Dodd, Paul Emerson; Vizkelethy, Gyorgy

2010-03-01

216

Design and testing of a high accuracy robotic single-cell manipulator  

E-print Network

We have designed, built and tested a high accuracy robotic single-cell manipulator to be able to pick individual cells from array of microwells, each 30 Pm or 50 pm cubed. Design efforts have been made for higher accuracy, ...

Yoon, Jun Young, S.M. Massachusetts Institute of Technology

2011-01-01

217

Stochastic simulation of a single inositol 1,4,5-trisphosphate-sensitive Ca2+ channel reveals repetitive openings during 'blip-like' Ca2+ transients.  

PubMed

Confocal microscope studies with fluorescent dyes of inositol 1,4,5-trisphosphate (InsP3)-induced intracellular Ca2+ mobilization recently established the existence of 'elementary' events, dependent on the activity of individual InsP3-sensitive Ca2+ channels. In the present work, we try by theoretical stochastic simulation to explain the smallest signals observed in those studies, which were referred to as Ca2+ 'blips' [Parker I., Yao Y. Ca2+ transients associated with openings of inositol trisphosphate-gated channels in Xenopus oocytes. J Physiol Lond 1996; 491: 663-668]. For this purpose, we assumed a simple molecular model for the InsP3-sensitive Ca2+ channel and defined a set of parameter values accounting for the results obtained in electrophysiological bilayer experiments [Bezprozvanny I., Watras J., Ehrlich B.E. Bell-shaped calcium-response curves of Ins(1,4,5)P3- and calcium-gated channels from endoplasmic reticulum of cerebellum. Nature 1991; 351: 751-754; Bezprozvanny I., Ehrlich B.E. Inositol (1,4,5)-trisphosphate (InsP3)-gated Ca channels from cerebellum: conduction properties for divalent cations and regulation by intraluminal calcium. J Gen Physiol 1994; 104: 821-856]. With a stochastic procedure which considered cytosolic Ca2+ diffusion explicitly, we then simulated the behaviour of a single channel, placed in a realistic physiological environment. An attractive result was that the simulated channel exhibited bursts of activity, arising from repetitive channel openings, which were responsible for transient rises in Ca2+ concentration and were reminiscent of the relatively long-duration experimental Ca2+ blips. The influence of the values chosen for the various parameters (affinity and diffusion coefficient of the buffers, luminal Ca2+ concentration) on the kinetic characteristics of these theoretical blips is analyzed. PMID:9681192

Swillens, S; Champeil, P; Combettes, L; Dupont, G

1998-05-01

218

STATUS OF HIGH POWER TESTS OF NORMAL CONDUCTING SINGLE-CELL STANDING WAVE STRUCTURES  

E-print Network

STATUS OF HIGH POWER TESTS OF NORMAL CONDUCTING SINGLE-CELL STANDING WAVE STRUCTURES B. Spataro. GEOMETRIES AND MATERIALS The single-cell standing wave structure consists of three parts: the input coupler cell is based on the geometry of a periodic accel- erator structure cell. In this paper we discuss

Istituto Nazionale di Fisica Nucleare (INFN)

219

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

220

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

221

Status of High Power Tests of Normal Conducting Single-Cell Structures  

SciTech Connect

We report the results of ongoing high power tests of single-cell standing wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the maximum gradient possibilities for normal-conducting rf powered particle beam accelerators. The test setup consists of reusable mode launchers and short test structures powered by SLACs XL-4 klystron. The mode launchers and structures were manufactured at SLAC and KEK and tested at the SLAC klystron test laboratory.

Dolgashev, V.A.; Tantawi, S.G.; /SLAC; Higashi, Y.; Higo, T.; /KEK, Tsukuba

2011-11-04

222

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...

223

Extensions of a Versatile Randomization Test for Assessing Single-Case Intervention Effects  

ERIC Educational Resources Information Center

The purpose of the present study was to investigate the statistical properties of two extensions of the Levin-Wampold (1999) single-case simultaneous start-point model's comparative effectiveness randomization test. The two extensions were (a) adapting the test to situations where there are more than two different intervention conditions and (b)…

Levin, Joel R.; Lall, Venessa F.; Kratochwill, Thomas R.

2011-01-01

224

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...

225

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

226

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

NASA Technical Reports Server (NTRS)

Proof testing was a useful supplement to conventional nondestructive evaluation (NDE) of space shuttle main engine (SSME) components. Since many of these components involve thin sections and high toughness materials, such as Inconel 718, conventional single-cycle proof test logic is not applicable due to the propensity for stable crack growth during the proof tests. Experience with five-cycle proof testing of SSME components is summarized and a framework is outlined for understanding multi-cycle proof testing using the fracture mechanics concept of a resistance curve. Extreme value statistics are also used to propose an empirical approach to compare the advantages and disadvantages of single- versus multi-cycle proof testing. The importance of the initial flaw size distribution and specimen thickness in such a comparison is also discussed.

Hudak, Stephen J., Jr.; Russell, Dale A.

1988-01-01

227

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

228

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

229

Comparative Performance of Four Single Extreme Outlier Discordancy Tests from Monte Carlo Simulations  

PubMed Central

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

Díaz-González, Lorena; Quiroz-Ruiz, Alfredo

2014-01-01

230

Numerical simulation of combined natural and forced convection during thermal-hydraulic transients. [LMFBR  

SciTech Connect

The single-phase COMMIX (COMponent MIXing) computer code performs fully three-dimensional, transient, thermal-hydraulic analyses of liquid-sodium LMFBR components. It solves the conservation equations of mass, momentum, and energy as a boundary-value problem in space and as an initial-value problem in time. The concepts of volume porosity, surface permeability and distributed resistance, and heat source have been employed in quasi-continuum (rod-bundle) applications. Results from three transient simulations involving forced and natural convection are presented: (1) a sodium-filled horizontal pipe initially of uniform temperature undergoing an inlet velocity rundown transient, as well as an inlet temperature transient; (2) a 19-pin LMFBR rod bundle undergoing a velocity transient; and, (3) a simulation of a water test of a 1/10-scale outlet plenum undergoing both velocity and temperature transients.

Domanus, H.M.; Sha, W.T.

1981-01-01

231

Use of multilocus methylation-specific single nucleotide primer extension (MS-SNuPE) technology in diagnostic testing for human imprinted loci.  

PubMed

A number of diseases have been found to be linked to aberrant methylation of specific genes. However, most of the routine diagnostic techniques to detect epigenetic disturbances are restricted to single loci. Additionally, a precise quantification of the methylation status is often hampered. A considerable fraction of patients with Silver-Russell syndrome, Beckwith-Wiedemann syndrome and transient neonatal diabetes mellitus exhibit loss of methylation at further imprinted loci in addition to the disease specific ones (multilocus methylation defects, MLMD). As the currently available tests are mainly focused on single imprinted loci on different chromosomes and thereby make the detection of multilocus methylation defects time-consuming and expensive, we established methylation-specific single nucleotide primer extension (MS-SNuPE) assays for a simultaneous quantification of methylation at multiple methylated loci. We chose loci generally affected in patients with MLMD. The method was validated by screening 66 individuals with known (epi)genetic disturbances. In comparison to other methylation-specific techniques, multilocus methylation-specific single nucleotide primer extension allows the quantitative analysis of numerous CpG islands of different loci in one assay and is, therefore, suitable for the simultaneous diagnostic testing for different congenital imprinting disorders in parallel, as well as for MLMD. PMID:22419125

Begemann, Matthias; Leisten, Isabelle; Soellner, Lukas; Zerres, Klaus; Eggermann, Thomas; Spengler, Sabrina

2012-05-01

232

A field test for companded single sideband modulation Implications for capacity enhancement and transmission planning  

NASA Astrophysics Data System (ADS)

A series of field tests of companded single sideband modulation (CSSB) technique for use in the Intelsat system is described. A 12-channel circuit group was tested between switches in Pittsburgh, and the Deutsche Bundespost (DBP) in Frankfurt via the Etam and Raisting satellite earth stations. A transponder bulk that included existing FDM-FM carriers was chosen to match the typical, Intelsat operating conditions, thus permitting the compatibility of FDM/FM and CSSB to be examined simultaneously. Results of objective performance tests are discussed, and a description of several subjective testing techniques is also given.

Wallace, E.; Adams, C.; Arnstein, D.

233

[Transient diplopia].  

PubMed

Transient binocular diplopia is a frequent complaint in an everyday ophthalmic practice. Since the objective clinical examination is most often within normal limits between the diplopia attacks, a thorough history is mandatory to determine the possible causes and precipitating factors. Although transient diplopia can herald visual or even life-threatening associated conditions, it is most often related to benign diseases. An appropriate work-up depends on the history and the clinical evaluation, targeting specific underlying causes. PMID:19944482

Milea, D

2009-12-01

234

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

235

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

236

Multiple Testing. Part I. Single-Step Procedures for Control of General Type I Error Rates  

Microsoft Academic Search

The present article proposes general single-step multiple testing procedures for controlling Type I error rates defined as arbitrary parameters of the distribution of the number of Type I errors, such as the generalized family-wise error rate. A key feature of our approach is the test statistics null distribution (rather than data generating null distribution) used to derive cut-offs (i.e., rejection

Sandrine Dudoit; Mark J. van der Laan; Katherine S. Pollard

2004-01-01

237

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

238

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

239

Single-Locus Tests of Microsatellite Evolution: Multi-Step Mutations and Constraints on Allele Size  

E-print Network

obtained from nine different baleen whale popula- tions. High agreement was found between results obSingle-Locus Tests of Microsatellite Evolution: Multi-Step Mutations and Constraints on Allele Size- tions; constraints on allele size; stepwise mutation model. INTRODUCTION Microsatellite loci

Nielsen, Rasmus

240

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...

241

The Power of Randomization Tests for Single-Case Phased Designs.  

ERIC Educational Resources Information Center

Monte Carlo methods were used to estimate the power of randomization tests used with single-case designs involving random assignment of treatments to phases. Simulations of two treatments and six phases showed an adequate level of power when effect sizes were large, phase lengths exceeded five, and autocorrelation was not negative. (SLD)

Ferron, John; Onghena, Patrick

1996-01-01

242

Detection of Cracks in Single-Crystalline Silicon Wafers Using Impact Testing  

Microsoft Academic Search

This thesis is about detection of cracks in single-crystalline silicon wafers by using a vibration method in the form of an impact test. The goal to detect cracks from vibration measurements introduced by striking the silicon wafer with an impact hammer. Such a method would reduce costs in the production of solar cells. It is an inexpensive, relatively simple method

Christina Hilmersson

2006-01-01

243

Craniometric variation in large-bodied hominoids: testing the single-species hypothesis for Homo habilis  

Microsoft Academic Search

The species question regarding Homo habilis remains unresolved. This study tests the null hypothesis that this hominid taxon represents a single paleospecies by comparing the fossils' magnitude and pattern of craniometric variation to samples of extant, large-bodied hominoids including Pan troglodytes, Gorilla gorilla, Pongo pygmaeus and Homo sapiens. Unlike previous quantitative approaches to this problem, randomization methodology is used to

Andrew Kramer; Steven M. Donnelly; James H. Kidder; Stephen D. Ousley; Stephen M. Olah

1995-01-01

244

Analysis and Testing of Ajax-based Single-page Web Applications  

E-print Network

Analysis and Testing of Ajax-based Single-page Web Applications PROEFSCHRIFT ter verkrijging van de.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Ajax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.2.1 Java.2.6 Reverse Ajax: Comet . . . . . . . . . . . . . . . . . . . . 10 1.3 Challenges and Research Questions

Mesbah, Ali

245

SINGLE ELEMENT TEST PREDICTIONS FOR STRESS-STRAIN BEHAVIOR OF PANKI FLY-ASH  

E-print Network

: Fly-ash is a waste product produced by burning of coal at thermal power plants. It is often used. Introduction Fly-ash is a fine powdery material, produced by burning of coal at thermal power plants. Fly-ash1 SINGLE ELEMENT TEST PREDICTIONS FOR STRESS-STRAIN BEHAVIOR OF PANKI FLY-ASH M. Waseem1 , A

Prashant, Amit

246

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

247

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

248

Experimental results of single screw mechanical tests: a follow-up to SAND2005-6036.  

SciTech Connect

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 evaluate fixture modifications and address issues of interest, including: fabrication of 45{sup o} test fixtures, measurement of the frictional load from the angled fixture guide, employment of electromechanical displacement transducers, development of a single-shear test, and study the affect of thread start orientation on single-shear behavior. A286 and 302HQ, No.10-32 socket-head cap screws were tested having orientations with respect to the primary loading axis of 0{sup 0}, 45{sup o}, 60{sup o}, 75{sup o} and 90{sup o} at stroke speeds 0,001 and 10 in/sec. The frictional load resulting from the angled screw fixture guide was insignificant. Load-displacement curves of A286 screws did not show a minimum value in displacement to failure (DTF) for 60{sup o} shear tests. Tests of 302HQ screws did not produce a consistent trend in DTF with load angle. The effect of displacement rate on DTF became larger as shear angle increased for both A286 and 302HQ screws.

Lee, Sandwook; Lee, Kenneth L.; Korellis, John S.; McFadden, Sam X.

2006-08-01

249

The Influence of Sarcoplasmic Reticulum Ca2+ Concentration on Ca2+ Sparks and Spontaneous Transient Outward Currents in Single Smooth Muscle Cells  

PubMed Central

Localized, transient elevations in cytosolic Ca2+, known as Ca2+ sparks, caused by Ca2+ release from sarcoplasmic reticulum, are thought to trigger the opening of large conductance Ca2+-activated potassium channels in the plasma membrane resulting in spontaneous transient outward currents (STOCs) in smooth muscle cells. But the precise relationships between Ca2+ concentration within the sarcoplasmic reticulum and a Ca2+ spark and that between a Ca2+ spark and a STOC are not well defined or fully understood. To address these problems, we have employed two approaches using single patch-clamped smooth muscle cells freshly dissociated from toad stomach: a high speed, wide-field imaging system to simultaneously record Ca2+ sparks and STOCs, and a method to simultaneously measure free global Ca2+ concentration in the sarcoplasmic reticulum ([Ca2+]SR) and in the cytosol ([Ca2+]CYTO) along with STOCs. At a holding potential of 0 mV, cells displayed Ca2+ sparks and STOCs. Ca2+ sparks were associated with STOCs; the onset of the sparks coincided with the upstroke of STOCs, and both had approximately the same decay time. The mean increase in [Ca2+]CYTO at the time and location of the spark peak was ?100 nM above a resting concentration of ?100 nM. The frequency and amplitude of spontaneous Ca2+ sparks recorded at ?80 mV were unchanged for a period of 10 min after removal of extracellular Ca2+ (nominally Ca2+-free solution with 50 ?M EGTA), indicating that Ca2+ influx is not necessary for Ca2+sparks. A brief pulse of caffeine (20 mM) elicited a rapid decrease in [Ca2+]SR in association with a surge in [Ca2+]CYTO and a fusion of STOCs, followed by a fast restoration of [Ca2+]CYTO and a gradual recovery of [Ca2+]SR and STOCs. The return of global [Ca2+]CYTO to rest was an order of magnitude faster than the refilling of the sarcoplasmic reticulum with Ca2+. After the global [Ca2+]CYTO was fully restored, recovery of STOC frequency and amplitude were correlated with the level of [Ca2+]SR, even though the time for refilling varied greatly. STOC frequency did not recover substantially until the [Ca2+]SR was restored to 60% or more of resting levels. At [Ca2+]SR levels above 80% of rest, there was a steep relationship between [Ca2+]SR and STOC frequency. In contrast, the relationship between [Ca2+]SR and STOC amplitude was linear. The relationship between [Ca2+]SR and the frequency and amplitude was the same for Ca2+ sparks as it was for STOCs. The results of this study suggest that the regulation of [Ca2+]SR might provide one mechanism whereby agents could govern Ca2+ sparks and STOCs. The relationship between Ca2+ sparks and STOCs also implies a close association between a sarcoplasmic reticulum Ca2+ release site and the Ca2+-activated potassium channels responsible for a STOC. PMID:9925820

ZhuGe, Ronghua; Tuft, Richard A.; Fogarty, Kevin E.; Bellve, Karl; Fay, Fredric S.; Walsh, John V.

1999-01-01

250

Tracer Tests in a Fractured Dolomite: 3. Analysis of Mass Transfer in Single-Well Injection-Withdrawal Tests  

SciTech Connect

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 most consistent with all available data, and is the only model to date that is capable of matching each of the recovery curves entirely. 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 ({minus}2. 1 to {minus}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 media, and are found to be a distinctive feature of multirate diffusion under SWIW test conditions. Fourth, we found that the estimated distributions of diffusion rate coefficients are very broad, with the distributions spanning a range of at least 3.6 to 5.7 orders of magnitude.

Haggerty, R.; Fleming, S.W.; Meigs, L.C.; McKenna, S.A.

1999-03-04

251

Evidence of Multi-Process Matrix Diffusion in a Single Fracturefrom a Field Tracer Test  

SciTech Connect

Compared to values inferred from laboratory tests on matrix cores, many field tracer tests in fractured rock have shown enhanced matrix diffusion coefficient values (obtained using a single-process matrix-diffusion model with a homogeneous matrix diffusion coefficient). To investigate this phenomenon, a conceptual model of multi-process matrix diffusion in a single-fracture system was developed. In this model, three matrix diffusion processes of different diffusion rates were assumed to coexist: (1) diffusion into stagnant water and infilling materials within fractures, (2) diffusion into a degraded matrix zone, and (3) further diffusion into an intact matrix zone. The validity of the conceptual model was then demonstrated by analyzing a unique tracer test conducted using a long-time constant-concentration injection. The tracer-test analysis was conducted using a numerical model capable of tracking the multiple matrix-diffusion processes. The analysis showed that in the degraded zone, a diffusion process with an enhanced diffusion rate controlled the steep rising limb and decay-like falling limb in the observed breakthrough curve, whereas in the intact matrix zone, a process involving a lower diffusion rate affected the long-term middle platform of slowly increasing tracer concentration. The different matrix-diffusion-coefficient values revealed from the field tracer test are consistent with the variability of matrix diffusion coefficient measured for rock cores with different degrees of fracture coating at the same site. By comparing to the matrix diffusion coefficient calibrated using single-process matrix diffusion, we demonstrated that this multi-process matrix diffusion may contribute to the enhanced matrix-diffusion-coefficient values for single-fracture systems at the field scale.

Zhou, Quanlin; Liu, Hui-Hai; Bodvarsson, Gudmundur; Molz, Fred J.

2005-06-11

252

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

E-print Network

We test experimentally the quantum ``paradox'' proposed by Lucien Hardy in 1993 [Phys. Rev. Lett. 71, 1665 (1993)] 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 non-contextuality, 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.

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

2014-03-22

253

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

254

Determining the effect of seawater on the interfacial shear strength of fiber reinforced epoxies using the single fiber fragmentation test  

E-print Network

. 4. 3 Test Conditions. 4. 4 Test Equipment. 14 15 16 17 5. RESULTS AND DISCUSSION. 20 5. 1 Moisture Absorption. 5. 2 Interfacial Shear Strength . . 5 3 Fiber Strength. 21 24 43 6. SUMMARY, CONCLUSIONS AND RECOMMENDATIONS . . . 46... the fragmentation process . . Figure 3 Free body diagram showing the stress state of a fiber in the single fiber fragmentation test Figure 4. Single fiber fragmentation test equipment schematic . . . 19 Figure 5. Moisture absorption data for Epoxy A system...

Pratt, Barbara Ann

1996-01-01

255

High-Gradient Tests of the Single-Cell SC Cavity with a Feedback Waveguide  

SciTech Connect

Use of a superconducting (SC) traveling-wave accelerating (STWA) structure with a small phase advance per cell, rather than a standing-wave structure, may provide a significant increase in the accelerating gradient in the ILC linac [1]. For the same surface electric and magnetic fields, the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing-wave cavities. In addition, the STWA allows longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed and manufactured to demonstrate the possibility of proper processing to achieve a high accelerating gradient. The first results of high-gradient tests of a prototype 1.3 GHz single-cell cavity with feedback waveguide will be presented.

Yakovlev, V.; Solyak, N.; Wu, G.; Ge, M.; Gonin, I.; Khabiboulline, T.; Ozelis, J.; Rowe, A. [Fermilab, Batavia, IL 60510 (United States); Avrakhov, P.; Kanareykin, A. [Euclid TechLabs, LLC, Solon, Ohio 44139 (United States); Rathke, J. [AES, Medford, NY 11763 (United States)

2010-11-04

256

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

257

Testing synthetic amyloid-? aggregation inhibitor using single molecule atomic force spectroscopy.  

PubMed

Alzheimer's disease is a neurodegenerative disease with no known cure and few effective treatment options. The principal neurotoxic agent is an oligomeric form of the amyloid-? peptide and one of the treatment options currently being studied is the inhibition of amyloid aggregation. In this work, we test a novel pseudopeptidic aggregation inhibitor designated as SG1. SG1 has been designed to bind at the amyloid-? self-recognition site and prevent amyloid-? from misfolding into ? sheet. We used atomic force spectroscopy, a nanoscale measurement technique, to quantify the binding forces between two single amyloid peptide molecules. For the first time, we demonstrate that single molecule atomic force spectroscopy can be used to assess the effectiveness of amyloid aggregation inhibitors by measuring the experimental yield of binding and can potentially be used as a screening technique for quick testing of efficacy of inhibitor drugs for amyloid aggregation. PMID:24321883

Hane, Francis T; Lee, Brenda Y; Petoyan, Anahit; Rauk, Arvi; Leonenko, Zoya

2014-04-15

258

Single-cell thermionic fuel element design and testing for space power systems  

SciTech Connect

The use of electric heaters in the single-cell thermionic fuel elements(TFE) of the Topaz-II power systems provides the ability to gain actual operating parameters of the power source prior to loading nuclear fuel. This feature can provide satellite payload designers with the output parameters of the power source that would be used for space operations. This design also allows personnel to work on the system after operation without the concerns associated with radioactive material produced from nuclear tests. The results of electrically testing a complete system provide a high level of confidence that the device will perform as expected in orbit.

Wold, S.K. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31

259

Feasibility of loophole-free nonlocality tests with a single photon  

SciTech Connect

Recently, much interest has been directed toward designing setups that achieve realistic loss thresholds for decisive tests of local realism--in particular in the optical regime. We analyze the feasibility of such Bell tests based on a W state shared between multiple parties, which can be realized, for example, by a single photon shared between spatial modes. We develop a general error model to obtain thresholds for the efficiencies required to violate local realism and also consider two concrete optical-measurement schemes.

Chaves, Rafael; Brask, Jonatan Bohr [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, ES-08860 Castelldefels (Barcelona) (Spain)

2011-12-15

260

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

261

An Experimental Study of Shear Damage Using In-Situ Single Shear Test  

Microsoft Academic Search

An experimental study has been performed to investigate the shear damage mechanism of aluminium alloy 2024T3 by an in-situ single shear test using scanning electron microscope (SEM). The observation of microstructural change and measurement of shear strain in mesoscale have been undertaken simultaneously. Hence, the shear damage mechanism and the shear stress–strain curve have been obtained. By measuring the deformed

C. Y. Tang; T. C. Lee; B. Rao; C. L. Chow

2002-01-01

262

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

263

Performance evaluation of pyrochlore ceramic waste forms by single pass flow through testing  

NASA Astrophysics Data System (ADS)

Titanate-based ceramic waste forms for the disposal of nuclear wastes have been the subjects of numerous studies over the past decades. In order to assess the performance of this ceramic in a potential Yucca Mountain high-level waste (HLW) repository, it is necessary to understand the kinetics and mechanisms of corrosion of the ceramic under repository conditions. To this end, we are conducting single pass flow-through (SPFT) dissolution tests on ceramics relevant to Pu disposition.

Zhao, P.; Bourcier, W. L.; Esser, B. K.; Shaw, H. F.

2000-07-01

264

Multiwavelength 'single-mode' erbium doped fiber laser for FFH-OCDMA testing  

Microsoft Academic Search

A single-mode multiwavelength EDF laser was realized for the first time in a ring cavity configuration. The laser exhibited flat response over 10 nm, with line spacing of 100 GHz and output power of 10 dBm. The laser was used to test a FFH-OCDMA telecommunication system with a rate of 10 Gchip\\/s and an equivalent transmission rate of 125 Gbit\\/s.

R. Slavik; S. LaRochelle

2002-01-01

265

Digital simulation, transient network analyzer and field tests of the closed loop control of the Eddy County SVC  

SciTech Connect

A static VAR compensator, SVC, was installed at the Eddy County substation near Artesia, New Mexico. It was put into commercial operation in April 1992. Before the commissioning period, a phase of extensive testing and analysis of the digital closed loop control was undertaken. This work was done using the actual control hardware and software in conjunction with an analog TNA and with digital simulation models of control and power systems. Results of this work were checked with the power system during field commissioning of the SVC. This paper gives an overview of the closed loop control design. It presents some results from the TNA tests, digital simulation and commissioning field tests of the SVC operation.

Bergmann, K.; Friedrich, B.G. (Siemens, Erlangen (Germany)); Stump, K. (Siemens Energy and Automation, Atlanta, GA (United States)); Elliott, W.H. (Southwestern Public Service, Amarillo, TX (United States))

1993-10-01

266

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. PMID:23445209

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

2014-01-01

267

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

268

In Situ Characterization of a Single Fracture Hydromechanical Behavior from Hydraulic Pulse Tests coupled to Simultaneous Pressure Normal  

E-print Network

In Situ Characterization of a Single Fracture Hydromechanical Behavior from Hydraulic Pulse Tests of the other surrounding fractures of the network. 1 INTRODUCTION Hydraulic pulse injection testing in single borehole has previously been applied to determine hydraulic properties of rock fractures, including

Vallée, Martin

269

Dynamic testing of a single-degree-of-freedom strapdown gyroscope  

NASA Technical Reports Server (NTRS)

Test methods and results are presented for the equivalent average input rate of a single-degree-of-freedom gyroscope operated both open loop and with a ternary-logic pulse-torque-to-balance loop during multiaxis angular oscillation. For the open-loop tests, good agreement was obtained with theoretical results. Two-axis testing was performed for oscillations about the Input-Output axes, the Input-Spin axes, and the Spin-Output axes. These tests run in the torque-to-balance mode revealed significant departures from open-loop results in the induced drift rate. An analysis is developed explaining much of the closed-loop data presented. Test data for the gryoscope in a ternary torque-to-balance loop with constant input rates is presented. The tests demonstrate that the instrument rate linearity does not change with interrogation frequency from 3,600 to 14,400 Hz if the torque coil is tuned to offer a resistive load to the current switch. Analysis cited shows that gyroscope lag compensation eliminates multiple pulsing and other equivalent forms of degraded resolution in a wide variety of quantizing loops. This result is test verified for the ternary delta-modulator loop.

Lory, C. B.; Feldman, J.; Sinkiewicz, J. S., Jr.

1971-01-01

270

Classifying performance impairment in response to sleep loss using pattern recognition algorithms on single session testing  

PubMed Central

There is currently no “gold standard” marker of cognitive performance impairment resulting from sleep loss. We utilized pattern recognition algorithms to determine which features of data collected under controlled laboratory conditions could most reliably identify cognitive performance impairment in response to sleep loss using data from only one testing session, such as would occur in the “real world” or field conditions. A training set for testing the pattern recognition algorithms was developed using objective Psychomotor Vigilance Task (PVT) and subjective Karolinska Sleepiness Scale (KSS) data collected from laboratory studies during which subjects were sleep deprived for 26 – 52 hours. The algorithm was then tested in data from both laboratory and field experiments. The pattern recognition algorithm was able to identify performance impairment with a single testing session in individuals studied under laboratory conditions using PVT, KSS, length of time awake and time of day information with sensitivity and specificity as high as 82%. When this algorithm was tested on data collected under real-world conditions from individuals whose data were not in the training set, accuracy of predictions for individuals categorized with low performance impairment were as high as 98%. Predictions for medium and severe performance impairment were less accurate. We conclude that pattern recognition algorithms may be a promising method for identifying performance impairment in individuals using only current information about the individual’s behavior. Single testing features (e.g., number of PVT lapses) with high correlation with performance impairment in the laboratory setting may not be the best indicators of performance impairment under real-world conditions. Pattern recognition algorithms should be further tested for their ability to be used in conjunction with other assessments of sleepiness in real-world conditions to quantify performance impairment in response to sleep loss. PMID:22959616

St. Hilaire, Melissa A.; Sullivan, Jason P.; Anderson, Clare; Cohen, Daniel A.; Barger, Laura K.; Lockley, Steven W.; Klerman, Elizabeth B.

2012-01-01

271

A Neutrality Test for Detecting Selection on DNA Methylation Using Single Methylation Polymorphism Frequency Spectrum  

PubMed Central

Inheritable epigenetic mutations (epimutations) can contribute to transmittable phenotypic variation. Thus, epimutations can be subject to natural selection and impact the fitness and evolution of organisms. Based on the framework of the modified Tajima’s D test for DNA mutations, we developed a neutrality test with the statistic “Dm” to detect selection forces on DNA methylation mutations using single methylation polymorphisms. With computer simulation and empirical data analysis, we compared the Dm test with the original and modified Tajima’s D tests and demonstrated that the Dm test is suitable for detecting selection on epimutations and outperforms original/modified Tajima’s D tests. Due to the higher resetting rate of epimutations, the interpretation of Dm on epimutations and Tajima’s D test on DNA mutations could be different in inferring natural selection. Analyses using simulated and empirical genome-wide polymorphism data suggested that genes under genetic and epigenetic selections behaved differently. We applied the Dm test to recently originated Arabidopsis and human genes, and showed that newly evolved genes contain higher level of rare epialleles, suggesting that epimutation may play a role in origination and evolution of genes and genomes. Overall, we demonstrate the utility of the Dm test to detect whether the loci are under selection regarding DNA methylation. Our analytical metrics and methodology could contribute to our understanding of evolutionary processes of genes and genomes in the field of epigenetics. The Perl script for the “Dm” test is available at http://fanlab.wayne.edu/ (last accessed December 18, 2014). PMID:25539727

Wang, Jun; Fan, Chuanzhu

2015-01-01

272

A rapid antimicrobial susceptibility test based on single-cell morphological analysis.  

PubMed

A rapid antibiotic susceptibility test (AST) is desperately needed in clinical settings for fast and appropriate antibiotic administration. Traditional ASTs, which rely on cell culture, are not suitable for urgent cases of bacterial infection and antibiotic resistance owing to their relatively long test times. We describe a novel AST called single-cell morphological analysis (SCMA) that can determine antimicrobial susceptibility by automatically analyzing and categorizing morphological changes in single bacterial cells under various antimicrobial conditions. The SCMA was tested with four Clinical and Laboratory Standards Institute standard bacterial strains and 189 clinical samples, including extended-spectrum ?-lactamase-positive Escherichia coli and Klebsiella pneumoniae, imipenem-resistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococci from hospitals. The results were compared with the gold standard broth microdilution test. The SCMA results were obtained in less than 4 hours, with 91.5% categorical agreement and 6.51% minor, 2.56% major, and 1.49% very major discrepancies. Thus, SCMA provides rapid and accurate antimicrobial susceptibility data that satisfy the recommended performance of the U.S. Food and Drug Administration. PMID:25520395

Choi, Jungil; Yoo, Jungheon; Lee, Mincheol; Kim, Eun-Geun; Lee, Ji Soo; Lee, Seungok; Joo, Seik; Song, Sang Hoon; Kim, Eui-Chong; Lee, Jung Chan; Kim, Hee Chan; Jung, Yong-Gyun; Kwon, Sunghoon

2014-12-17

273

A closed-form analytical solution for thermal single-well injection-withdrawal tests  

NASA Astrophysics Data System (ADS)

Thermal single-well injection-withdrawal (SWIW) tests entail pumping cold water into a hot and usually fractured reservoir, and monitoring the temperature recovery during subsequent backflow. Such tests have been proposed as a potential means to characterize properties of enhanced geothermal systems (EGS), such as fracture spacing, connectivity, and porosity. In this paper we develop an analytical solution for thermal SWIW tests, using an idealized model of a single vertical fracture with linear flow geometry embedded in impermeable conductive wall rocks. The analytical solution shows that the time dependence of temperature recovery is dominated by the heat exchange between fracture and matrix rock, but strong thermal diffusivities of rocks as compared to typical solute diffusivities are not necessarily advantageous for characterizing fracture-matrix interactions. The effect of fracture aperture on temperature recovery during backflow is weak, particularly when the fracture aperture is smaller than 0.1 cm. The solution also shows that temperature recovery during backflow is independent of the applied injection and backflow rates. This surprising result implies that temperature recovery is independent of the height of the fracture, or the specific fracture-matrix interface areas per unit fracture length, suggesting that thermal SWIW tests will not be able to characterize fracture growth that may be achieved by stimulation treatments.

Jung, Yoojin; Pruess, Karsten

2012-03-01

274

Genetic evaluation of bulls and cows with single- and multiple-country test-day models.  

PubMed

First-lactation milk yield test-day records on cows from Australia, Canada, Italy, and New Zealand were analyzed by single- and multiple-country random regression models. Models included fixed effects of herd-test day and breed composition-age at calving-season of calving by days in milk, and random regressions with Legendre polynomials of order four for animal genetic and permanent environmental effects. Milk yields in different countries were defined as genetically different traits for the purpose of multiple-trait model. Estimated breeding values of bulls and cows from single- and multiple-trait models were compared within and across countries for two traits: total milk yield in lactation and lactation persistency, defined as the linear coefficient of animal genetic curve. Correlations between single- and multiple-trait evaluations within country for total yield were higher than 0.95 for bulls and close to 1 for cows. Correlations for lactation persistency were lower than respective correlations for total yield. Between country correlations for lactation yield ranged from 0.93 to 0.96, indicating different ranking of bulls on different country scales under multiple-trait model. Lactation persistency had in general lower between-country correlations, with the highest values for Canada-Italy and Australia-New Zealand pairs, for both single- and multiple-country models. Although multiple-country random regression test-day model was computationally feasible for four countries, the same would not be true for routine international genetic evaluation in the near future. PMID:12146495

Jamrozik, J; Schaeffer, L R; Weigel, K A

2002-06-01

275

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

276

A Monte Carlo test of linkage disequilibrium for single nucleotide polymorphisms  

PubMed Central

Background Genetic association studies, especially genome-wide studies, make use of linkage disequilibrium(LD) information between single nucleotide polymorphisms (SNPs). LD is also used for studying genome structure and has been valuable for evolutionary studies. The strength of LD is commonly measured by r2, a statistic closely related to the Pearson's ?2 statistic. However, the computation and testing of linkage disequilibrium using r2 requires known haplotype counts of the SNP pair, which can be a problem for most population-based studies where the haplotype phase is unknown. Most statistical genetic packages use likelihood-based methods to infer haplotypes. However, the variability of haplotype estimation needs to be accounted for in the test for linkage disequilibrium. Findings We develop a Monte Carlo based test for LD based on the null distribution of the r2 statistic. Our test is based on r2 and can be reported together with r2. Simulation studies show that it offers slightly better power than existing methods. Conclusions Our approach provides an alternative test for LD and has been implemented as a R program for ease of use. It also provides a general framework to account for other haplotype inference methods in LD testing. PMID:21492446

2011-01-01

277

Single-neuron axonal pathfinding under geometric guidance: low-dose-methylmercury developmental neurotoxicity test.  

PubMed

Because the nervous system is most vulnerable to toxicants during development, there is a crucial need for a highly sensitive developmental-neurotoxicity-test model to detect potential toxicants at low doses. We developed a lab-on-chip wherein single-neuron axonal pathfinding under geometric guidance was created using soft lithography and laser cell-micropatterning techniques. After coating the surface with L1, an axon-specific member of the Ig family of cell adhesion molecules (CAMs), and optimizing microunit geometric parameters, we introduced low-dose methylmercury, a well-known, environmentally significant neurotoxicant, in the shared medium. Its developmental neurotoxicity was evaluated using a novel axonal pathfinding assay including axonal turning and branching rates at turning points in this model. Compared to the conventional neurite-outgrowth assay, this model's detection threshold for low-dose methylmercury was 10-fold more sensitive at comparable exposure durations. These preliminary results support study of developmental effects of known and potential neurotoxicants on axon pathfinding. This novel assay model would be useful to study neuronal disease mechanisms at the single-cell level. To our knowledge, the potential of methylmercury chloride to cause acute in vitro developmental neurotoxicity (DNT) at such a low dosage has not been reported. This is the first DNT test model with high reproducibility to use single-neuron axonal pathfinding under precise geometric guidance. PMID:25041816

Wei, Lina; Sweeney, Andrew J; Sheng, Liyuan; Fang, Yu; Kindy, Mark S; Xi, Tingfei; Gao, Bruce Z

2014-09-21

278

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 Central

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

2014-01-01

279

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

SciTech Connect

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 to explain the significant observed behaviors of the pressure and the temperature of the EV steam outlet, and the temperature of water supply distributing piping till 600 seconds after the turbine trip. The analysis results of these behaviors showed good agreement with the test results based on results of parameter study as the blow efficiency (release coef.) and heat transferred from the helical coil region to the down-comer (temperature heating down-comer tubes). It was found that the RELAP5/MOD3 code with a two-fluids model can predict well the physical situation: the gas-phase of steam generated by the decompression boiling moves upward in the down-comer tubes accompanied by the enthalpy increase of the water supply chambers; and that the pressure change of a 'shoulder' like shape is induced by the mass balance between the steam mass generated in the down-comer tubes and the steam mass blown from the SG. The applicability of RELAP5/MOD3 to SG modeling was confirmed by simulating the actual FBR system. (authors)

Yoshihisa Shindo; Hiroshi Endo; Tomoko Ishizu; Kazuo Haga [Japan Nuclear Energy Safety Organization (Japan)

2006-07-01

280

Proposal of a test bench for switched reluctance motors and fractional-horsepower single-phase induction motors  

Microsoft Academic Search

This study addresses a proposal of a bench to test single-phase induction motors and switched reluctance motors with rated power up to 1 hp. The bench was set up so that single-phase induction motor tests meet requirements of IEEE Std. 114–2001 and the Brazilian related Standard (ABNT NBR 5383-2\\/2008). In addition, the test procedures for reluctance motors comprise sequential steps

W. C. E. Teixeira; G. P. Viajante; E. G. Marra; B. Alvarenga; M. C. Costa; I. E. Chabu; J. R. Cardoso

2009-01-01

281

Proposal of a test bench for switched reluctance motors and fractional-horsepower single-phase induction motors  

Microsoft Academic Search

This study addresses a proposal of a bench to test single-phase induction motors and switched reluctance motors with rated power up to 1 hp. The bench was set up so that single-phase induction motor tests meet requirements of IEEE Std. 114-2001 and the Brazilian related Standard (ABNT NBR 5383-2\\/2008). In addition, the test procedures for reluctance motors comprise sequential steps

W. C. E. Teixeira; G. P. Viajante; E. G. Marra; B. Alvarenga; M. C. Costa; I. E. Chabu; J. R. Cardoso

2009-01-01

282

Temperature in a J47-25 Turbojet-engine Combustor and Turbine Sections During Steady-state and Transient Operation in a Sea-level Test Stand  

NASA Technical Reports Server (NTRS)

In order to determine the conditions of engine operation causing the most severe thermal stresses in the hot parts of a turbojet engine, a J47-25 engine was instrumented with thermocouples and operated to obtain engine material temperatures under steady-state and transient conditions. Temperatures measured during rated take-off conditions of nozzle guide vanes downstream of a single combustor differed on the order of 400 degrees F depending on the relation of the blades position to the highest temperature zone of the burner. Under the same operation conditions, measured midspan temperatures in a nozzle guide vane in the highest temperature zone of a combustor wake ranged from approximately 1670 degrees F at leading and trailing edges to 1340 degrees F at midchord on the convex side of the blade. The maximum measured nozzle-guide-vane temperature of 1920degrees at the trailing edge occurred during a rapid acceleration from idle to rated take-off speed following which the tail-pipe gas temperature exceeded maximum allowable temperature by 125 degrees F.

Morse, C R; Johnston, J R

1955-01-01

283

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

284

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

285

Transient effect of single dose exposure of Nigerian Bonny-light crude oil on testicular steroidogenesis in Wistar rats is accompanied by oxidative stress.  

PubMed

Abstract The folkloric use of Nigerian Bonny-light crude oil (BLCO) in Niger Delta area of Nigeria is a common practice. There is increasing experimental evidence portending the adverse effects of BLCO an environmental toxicant on testicular function. We investigated the effects of single dose of BLCO (800?mg/kg body weight) on the activities of steroidogenic and antioxidant enzymes such as serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, 3 ?-hydroxy-steroid dehydrogenase (3 ?-HSD), 17 ?-hydroxy-steroid dehydrogenase (17 ?-HSD), superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px), levels of lipid peroxidation (LPO), glutathione reduced (GSH) and steroidogenic acute regulatory (StAR) protein, in testes of rats. There was a sequential reduction in the concentration of steroid hormones and activities of steroidogenic enzymes with a concomitant decrease in levels of StAR protein, followed by a parallel increase in antioxidant enzyme activities and levels of LPO. These findings revealed inhibitory effects of BLCO on testicular steroidogenesis and the possible role of oxidative stress in testicular dysfunction observed in this study. PMID:25388509

Ebokaiwe, Azubuike Peter; Ramesh, Parjapath; Mathur, Premendu Prakash; Farombi, Ebenezer Olatunde

2014-11-12

286

Event-by-event simulation of single-neutron experiments to test uncertainty relations  

NASA Astrophysics Data System (ADS)

Results from a discrete-event simulation of a recent single-neutron experiment that tests Ozawa?s generalization of Heisenberg?s uncertainty relation are presented. The event-based simulation algorithm reproduces the results of the quantum theoretical description of the experiment but does not require the knowledge of the solution of a wave equation, nor does it rely on detailed concepts of quantum theory. In particular, the data from these non-quantum simulations satisfy uncertainty relations derived in the context of quantum theory. Invited paper presented at QTAP-6.

De Raedt, H.; Michielsen, K.

2014-12-01

287

Testing for Renewal and Detailed Balance Violations in Single-Molecule Blinking Processes James B. Witkoskie and Jianshu Cao*  

E-print Network

Testing for Renewal and Detailed Balance Violations in Single-Molecule Blinking Processes James B balance violations, and experimental condition dependences. The tests are simple to implement and allow, Massachusetts 02139 ReceiVed: March 9, 2006; In Final Form: July 28, 2006 This paper examines methods to test

Cao, Jianshu

288

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

289

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

290

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

291

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. PMID:21468319

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

2011-01-01

292

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

293

SRAM single event upset calculation and test using protons in the secondary beam in the BEPC  

NASA Astrophysics Data System (ADS)

The protons in the secondary beam in the Beijing Electron Positron Collider (BEPC) are first analyzed and a large proportion at the energy of 50-100 MeV supply a source gap of high energy protons. In this study, the proton energy spectrum of the secondary beam was obtained and a model for calculating the proton single event upset (SEU) cross section of a static random access memory (SRAM) cell has been presented in the BEPC secondary beam proton radiation environment. The proton SEU cross section for different characteristic dimensions has been calculated. The test of SRAM SEU cross sections has been designed, and a good linear relation between SEUs in SRAM and the fluence was found, which is evidence that an SEU has taken place in the SRAM. The SEU cross sections were measured in SRAM with different dimensions. The test result shows that the SEU cross section per bit will decrease with the decrease of the characteristic dimensions of the device, while the total SEU cross section still increases upon the increase of device capacity. The test data accords with the calculation results, so the high-energy proton SEU test on the proton beam in the BEPC secondary beam could be conducted.

Yuanming, Wang; Hongxia, Guo; Fengqi, Zhang; Keying, Zhang; Wei, Chen; Yinhong, Luo; Xiaoqiang, Guo

2011-09-01

294

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

295

A Transient Numerical Simulation of Perched Ground-Water Flow at the Test Reactor Area, Idaho National Engineering and Environmental Laboratory, Idaho, 1952-94  

SciTech Connect

Studies of flow through the unsaturated zone and perched ground-water zones above the Snake River Plain aquifer are part of the overall assessment of ground-water flow and determination of the fate and transport of contaminants in the subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL). These studies include definition of the hydrologic controls on the formation of perched ground-water zones and description of the transport and fate of wastewater constituents as they moved through the unsaturated zone. The definition of hydrologic controls requires stratigraphic correlation of basalt flows and sedimentary interbeds within the saturated zone, analysis of hydraulic properties of unsaturated-zone rocks, numerical modeling of the formation of perched ground-water zones, and batch and column experiments to determine rock-water geochemical processes. This report describes the development of a transient numerical simulation that was used to evaluate a conceptual model of flow through perched ground-water zones beneath wastewater infiltration ponds at the Test Reactor Area (TRA).

B. R. Orr (USGS)

1999-11-01

296

Test Analysis Correlation of the Single Stringer Bending Tests for the Space Shuttle ET-137 Intertank Stringer Crack Investigation  

NASA Technical Reports Server (NTRS)

On November 5, 2010, Space Shuttle mission STS-133 was scrubbed due to a hydrogen leak at the Ground Umbilical Carrier Plate (GUCP). After the scrub, a crack in the foam thermal protection system (TPS) was observed on the External Tank (ET) near the interface between the liquid oxygen (LOX) tank and the Intertank. When the damaged foam was removed, two 9-in. long cracks were found on the feet of Intertank stringer S7-2, and the stringer failure was the cause of the TPS crack. An investigation was conducted to determine the root cause of the cracks, establish a remedy/repair for the stringers, and provide flight rationale for the damaged tank, ET-137. The Space Transportation System (STS) Super Lightweight ET (SLWT) is comprised of two propellant tanks (an aft liquid hydrogen (LH2) tank and a forward LOX tank) and an Intertank. The Intertank serves as the structural connection between the two propellant tanks and also functions to receive and distribute all thrust loads from the solid rocket boosters . The Intertank is a stiffened cylinder structure consisting of eight mechanically joined panels (two integrally-stiffened, machined thrust panels to react the booster loads and six stringer-stiffened skin panels). There are one main ring frame, four intermediate ring frames, and forward and aft flange chords that mate to the respective propellant tanks.. The skin/stringer panels utilize external hat-section stringers that are mechanically attached with rivets along most of their length and with specialty fasteners, such as GP Lockbolts and Hi-Loks, at the forward and aft ends where the stringers attach to the flange chords. During the STS-133 Intertank stringer crack investigation, cracks were found on a total of five stringers. All of the cracks were at the LOX end, in the feet of the stringers, and near the forward fasteners (GP Lockbolts). Video of tanking for the November 5 launch attempt was used to determine that the TPS failure, and thus the stringer failure, occurred as the LOX liquid level crossed the LOX tank / Intertank interface ring frame. Hence, cryogenically-induced displacements were suspected as a contributing cause of the stringer cracks. To study the behavior of Intertank stringers subjected to similar displacements, static load tests of individual stringers, colloquially known as "single stringer bending tests" were performed. Approximately thirty stringers were tested, many of which were cut from the partially completed Intertank for what would have been ET-139. In addition to the tests, finite element (FE) analyses of the test configuration were also performed. In this paper, the FE analyses and test-analysis correlation for stringer test S6-8 are presented. Stringer S6-8 is a "short chord" configuration with no doubler panels.

Phillips, Dawn R.; Saxon, Joseph B.; Wingate, Robert J.

2012-01-01

297

Precision Experiments with Single Particles in Ion Traps for Tests of Fundamental Interactions  

NASA Astrophysics Data System (ADS)

Ion trap technology has made it possible to store, cool and observe single ions or ensembles of few ions under well controlled experimental conditions and at very low temperatures [1]. Single particles in traps allow for clean investigations of basic interactions and also for the determination of fundamental constants. This has been demonstrated by investigations of Quantum Electrodynamics (QED) with respect to the g-factor of the free electron [2] and of the electron bound in hydrogen-like carbon and oxygen [3], which form the most precise determinations of the fine-structure constant and of the mass of the electron, respectively. A precision test of CPT invariance has been performed in a proton-antiproton mass comparison with single particles in a Penning trap [4]. Optical quantum jump spectroscopy with single laser-cooled ions in rf traps has paved the way for optical frequency standards and for the investigation of a possible variation of fundamental constants. With the novel technique of deceleration, trapping and cooling, even high-accuracy experiments with highly charged ions up to uranium U91+ will be possible at the HITRAP facility at GSI Darmstadt [5]. [1] Observation of a Phase Transition of Stored Laser-Cooled Ions, F. Diedrich, E. Peik, J.M. Chen, W. Quint, H. Walther, Phys. Rev. Lett. 59, 2931 (1987) [2] New Determination of the Fine Structure Constant from the Electron g Value and QED, G. Gabrielse et al., Phys. Rev. Lett. 97, 030802 (2006). [3] New Determination of the Electron's Mass, T. Beier et al., Phys. Rev. Lett. 88, 011603 (2002). [4] Precision Mass Spectroscopy of the Antiproton and Proton Using Simultaneously Trapped Particles, G. Gabrielse et al., Phys. Rev. Lett. 82, 3198 (1999). [5] Trapping ions of hydrogen-like uranium: The HITRAP project at GSI, T. Beier et al., NIM B 235, 473 (2005).

Quint, Wolfgang

2007-06-01

298

Thermo-mechanical behaviour of a single slice test device for the FRIB high power target  

NASA Astrophysics Data System (ADS)

One of the major challenges of the FRIB project (Facility for Rare Isotope Beams) at Michigan State University is the design and integration of the production target to produce rare isotope beams via fragmentation reaction. In the most extreme case, a 400 kW uranium beam of 200 MeV/u will be focused in a 1 mm diameter spot, leading to a power density of 60 MW/cm 3 for a C target. Up to 200 kW may be dissipated in the target. A rotating solid carbon disk concept has been selected as the target design approach for all primary beams up to uranium to provide high-power operation. A high rotational speed is necessary to compensate for the high power density. A multi-slice approach allows the evacuation of the large amount of heat deposited by the increase of the radiating area. In the present design study, the multi-slice target device has a diameter of about 30 cm and rotates at about 5000 RPM (revolutions per minute). The first step of the R&D strategy consists in the development and test of a 20 kW single-slice target prototype. This single disk device is designed to accept the same fraction of power as each disk of the final multi-slice target. Critical information on thermal-mechanical properties can be obtained thus at a lower power level than the one of the full device. Different carbon materials were tested. An electron beam of ˜20 keV was used for the thermal tests. Simulations were performed using the ANSYS code for the thermo-mechanical behaviour of the target, the resulting deformation and the stress profiles of heated graphite disks. Results of the simulations were compared with experimental data.

Pellemoine, F.; Mittig, W.; Avilov, M.; Ippel, D.; Lenz, J.; Oliva, J.; Silverman, I.; Youchison, D.; Xu, T.

2011-11-01

299

Semi-analytic approach to analyze single well tracer tests TR-44  

SciTech Connect

Residual oil saturation is one of the most important parameters to be considered when analyzing a prospective field for enhanced oil recovery. Traditionally, residual oil saturation has been estimated from cores or well logs. These methods have a small radius of investigation, evaluating saturations in a region close to the wellbore. This region is often affected by injection or production operations. Single well tracer tests have proven to be a better alternative to estimate residual oil saturation since they cover a substantially larger volume of the reservoir, and thus measure a more representative residual oil saturation of the target formation. The method consists of the injection of a reactive tracer that is soluble in oil and water. This tracer slowly hydrolyzes forming a secondary tracer as a product of an irreversible chemical reaction. After injection, the well is shut in to allow the formation of a detectable amount of secondary tracer, which is soluble only in water. When the well is open to production, each tracer arrives to the well at different times. From the separation between the concentration peaks, residual oil saturation is estimated. However, the determination of the residual oil saturation through the analysis of single well tracer test production data, in the past, has required: 1) the use of finite difference simulators, 2) five fitting parameters and 3) considerable man-computer interaction time. In addition finite difference simulators give results that are affected by numerical dispersion. This, and the fitting parameters, add uncertainty to the uniqueness of the solution. In this work, a new approach is presented. The test is analyzed. 28 references, 70 figures, 7 tables.

Antunez, E.U.

1984-08-01

300

Single-Crystal NiAl-X Alloys Tested for Hot Corrosion  

NASA Technical Reports Server (NTRS)

Single-crystal nickel aluminide (NiAl) has been investigated extensively throughout the last several years as a potential structural material in aero-gas turbine engines. The attractive features of NiAl in comparison to Ni-base superalloys include a higher melting point, lower density, higher thermal conductivity, and excellent oxidation resistance. However, NiAl suffers from a lack of ductility and fracture toughness at low temperatures and a low creep strength at high temperatures. Alloying additions of hafnium (Hf), gallium (Ga), titanium (Ti), and chromium (Cr) have each shown some benefit to the mechanical properties over that of the binary alloy. However, the collective effect of these alloying additions on the environmental resistance of NiAl-X was unclear. Hence, the present study was undertaken to examine the hot corrosion behavior of these alloys. A companion study examined the cyclic oxidation resistance of these alloys. Several single-crystal NiAl-X alloys (where X is Hf, Ti, Cr, or Ga) underwent hot corrosion testing in a Mach 0.3 burner rig at the NASA Lewis Research Center. Samples were tested for up to 300 1-hr cycles at a temperature of 900 C. It was found that increasing the Ti content from 1 to 5 at.% degraded the hot corrosion behavior. This decline in the behavior was reflected in high weight gains and large corrosion mound formation during testing (see the figures). However, the addition of 1 to 2 at.% Cr to alloys containing 4 to 5 at.% Ti appeared to greatly reduce the susceptibility of these alloys to hot corrosion attack and negated the deleterious effect of the increased Ti addition.

Nesbitt, James A.

1999-01-01

301

Preimplantation genetic haplotyping: 127 diagnostic cycles demonstrating a robust, efficient alternative to direct mutation testing on single cells  

Microsoft Academic Search

Preimplantation genetic diagnosis using whole genome amplification and a haplotyping approach (PGH) was first described in 2006 and suggested as an efficient alternative to single-cell PCR for monogenic disorders. DNA from single cells was amplified using multiple displacement amplification; the resulting products were then tested using disease-specific PCR multiplexes applied under standard laboratory conditions to determine the haplotypes in the

Pamela Renwick; Jane Trussler; Alison Lashwood; Peter Braude; Caroline Mackie Ogilvie

2010-01-01

302

Additive Manufacturing Thermal Performance Testing of Single Channel GRCop-84 SLM Components  

NASA Technical Reports Server (NTRS)

The surface finish found on components manufactured by sinter laser manufacturing (SLM) is rougher (0.013 - 0.0006 inches) than parts made using traditional fabrication methods. Internal features and passages built into SLM components do not readily allow for roughness reduction processes. Alternatively, engineering literature suggests that the roughness of a surface can enhance thermal performance within a pressure drop regime. To further investigate the thermal performance of SLM fabricated pieces, several GRCop-84 SLM single channel components were tested using a thermal conduction rig at MSFC. A 20 kW power source running at 25% duty cycle and 25% power level applied heat to each component while varying water flow rates between 2.1 - 6.2 gallons/min (GPM) at a supply pressure of 550 to 700 psi. Each test was allowed to reach quasi-steady state conditions where pressure, temperature, and thermal imaging data were recorded. Presented in this work are the heat transfer responses compared to a traditional machined OHFC Copper test section. An analytical thermal model was constructed to anchor theoretical models with the empirical data.

Garcia, Chance P.; Cross, Matthew

2014-01-01

303

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

304

Transient and steady-state selection in the striatal microcircuit  

PubMed Central

Although the basal ganglia have been widely studied and implicated in signal processing and action selection, little information is known about the active role the striatal microcircuit plays in action selection in the basal ganglia-thalamo-cortical loops. To address this knowledge gap we use a large scale three dimensional spiking model of the striatum, combined with a rate coded model of the basal ganglia-thalamo-cortical loop, to asses the computational role the striatum plays in action selection. We identify a robust transient phenomena generated by the striatal microcircuit, which temporarily enhances the difference between two competing cortical inputs. We show that this transient is sufficient to modulate decision making in the basal ganglia-thalamo-cortical circuit. We also find that the transient selection originates from a novel adaptation effect in single striatal projection neurons, which is amenable to experimental testing. Finally, we compared transient selection with models implementing classical steady-state selection. We challenged both forms of model to account for recent reports of paradoxically enhanced response selection in Huntington's disease patients. We found that steady-state selection was uniformly impaired under all simulated Huntington's conditions, but transient selection was enhanced given a sufficient Huntington's-like increase in NMDA receptor sensitivity. Thus our models provide an intriguing hypothesis for the mechanisms underlying the paradoxical cognitive improvements in manifest Huntington's patients. PMID:24478684

Tomkins, Adam; Vasilaki, Eleni; Beste, Christian; Gurney, Kevin; Humphries, Mark D.

2014-01-01

305

SEU and Test Considerations for FPGA Devices  

NASA Technical Reports Server (NTRS)

This viewgraph presentation provides an overview of Field Programmable Gate Arrays (FPGAs), what they are, implementations in space missions, and current available technologies. Single Event Upsets (SEUs) and Single Event Transients (SETs) are discussed in relation to their effects on FPGAs. Testing goals, considerations, and data analysis are reviewed.

Berg, Malanie

2006-01-01

306

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

307

Modeling Single Well Injection-Withdrawal (SWIW) Tests for Characterization of Complex Fracture-Matrix Systems  

NASA Astrophysics Data System (ADS)

An essential condition for performance evaluation of enhanced geothermal systems (EGS) resides in the ability to reliably predict fluid flow and heat transport in fractured porous rocks, where fast convection-dispersive transport through the fracture network can be strongly affected by heat conduction into the adjacent rock matrix. SWIW tests are single-well tracer tests that involve an initial period of fluid and tracer injection followed by a period of fluid withdrawal. As a result of the flow field reversal, the measured breakthrough curves tend to be less sensitive to advective heterogeneities and more sensitive to matrix diffusion and sorption, making this method very valuable in characterizing fracture-matrix interaction and evaluating matrix properties. In particular, we propose using SWIW tests before and after hydrofracking operations, to help assess the means by which hydrofracking increases permeability and enhances fracture-matrix interaction. In the present study, we have modeled single-well injection-withdrawal (SWIW) tests for non-sorbing and sorbing tracers, using the mixed Eulerian-Lagrangian transport simulator TRIPOLY, which solves tracer advection and dispersion in fracture networks together with solute exchange processes between the fractures and the porous matrix. Our simulations were conducted for hypothetical but workable SWIW test designs considering a variety of statistically generated 2D fracture-matrix systems. Parameter sensitivity studies were completed on three physical parameters of the rock matrix, namely porosity, diffusion coefficient and retardation coefficient, in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, was modeled in two different ways, one by increasing the fracture aperture for flow and the other one by adding a new set of fractures to the fracture network. The results of all these different tests were analyzed by studying the population of matrix blocks, the tracer spatial distribution, and the breakthrough curves (BTCs), while performing mass balance checks to ensure numerical accuracy. The possibility of inferring from SWIW-test BTCs relevant information on the physical parameters of the fracture-matrix system was investigated. Our results clearly demonstrate the importance of matrix effects in the solute transport process. The sensitivity studies illustrate the increased importance of the matrix as providing a retardation mechanism as matrix porosity, diffusion coefficient, or retardation coefficient increase. Heat convection and conduction can be shown to be mathematically equivalent to advection, diffusion, and sorption of tracer, making these tracer studies directly useful for analysis of EGS. Interestingly, preliminary results before and after hydrofracking are insensitive to adding more fractures while somewhat sensitive to aperture increase, making SWIW tests a possible means of discriminating between these two potential hydrofracking effects. However, our base case fracture network is highly connected, potentially minimizing the effect of hydrofracking. Further study is needed using a sparser network to study hydrofracking under more realistic conditions.

Cotte, F.; Doughty, C.; Birkholzer, J. T.

2010-12-01

308

Heavy ion linear energy transfer measurements during single event upset testing of electronic devices  

SciTech Connect

A heavy ion beam diagnostic system installed at the Brookhaven Single Event Upset Test Facility is described. Calibration of the system with the help of {alpha}-particles, essential for linear energy transfer (LET) measurements, is discussed. Measured LET values for 20 different ions, including {sup 7}Li, {sup 9}B, {sup 12}C, {sup 16}O, {sup 19}F, {sup 28}Si, {sup 32}S, {sup 35}Cl, {sup 40}Ca, {sup 45}Sc, {sup 48}Ti, {sup 56}Fe, {sup 58}Ni, {sup 63}Cu, {sup 74}Ge, {sup 79}Br, {sup 107}Ag, {sup 127}I, {sup 197}Au, and {sup 235}U, with energies between 0.5 and 8.5 MeV/AMU but not exceeding 400 MeV for the heaviest ions, are presented in both graphical and numerical forms. Results are compared to predictions of the TRIM-90 simulation program, with an average difference between the measured and calculated values of 2 {+-} 6%.

Zajic, V.; Thieberger, P. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States)

1999-02-01

309

An Experimental Proposal to Test Dynamic Quantum Non-locality with Single-Atom Interferometry  

E-print Network

Quantum non-locality based on the well-known Bell inequality is of kinematic nature. A different type of quantum non-locality, the non-locality of the quantum equation of motion, is recently put forward with connection to the Aharonov-Bohm effect [Nature Phys. 6, 151 (2010)]. Evolution of the displacement operator provides an example to manifest such dynamic quantum non-locality. We propose an experiment using single-atom interferometry to test such dynamic quantum non-locality. We show how to measure evolution of the displacement operator with clod atoms in a spin-dependent optical lattice potential and discuss signature to identify dynamic quantum non-locality under a realistic experimental setting.

Shi-Liang Zhu; Zheng-Yuan Xue; Dan-Wei Zhang; Lu-Ming Duan

2010-09-14

310

Single and multiple impact ignition of new and aged high explosives in the Steven Impact Test  

SciTech Connect

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; DePiero, A H; Garza, R G; Tarver, C M

1999-06-01

311

Approach avoidance training in the eating domain: Testing the effectiveness across three single session studies.  

PubMed

Dual-process models propose that impulsive behavior plays a key role in the development and maintenance of maladaptive eating patterns. Research outside the eating domain suggests that approach avoidance training, a paradigm which aims to modify automatic behavioral dispositions toward critical stimuli, is an effective tool to weaken unhealthy impulses. The present research tested the effectiveness of approach avoidance training in the eating domain. We conducted three single session studies with varying methodologies in a normal-weight female student population (total N?=?258), in which one group was always trained to avoid pictures of unhealthy food and to approach pictures of healthy food or neutral objects. We found no conclusive evidence that approach avoidance training can change participants' implicit and explicit food preferences and eating behavior. We discuss the potential and the limitations of approach avoidance training in the eating domain and provide suggestions for future research avenues. PMID:25447011

Becker, Daniela; Jostmann, Nils B; Wiers, Reinout W; Holland, Rob W

2015-02-01

312

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

313

Numerical inverse interpretation of single-hole pneumatic tests in unsaturated fractured tuff.  

PubMed

A numerical inverse method was used to interpret simultaneously multirate injection and recovery data from single-hole pneumatic tests in unsaturated fractured tuff at the Apache Leap Research Site near Superior, Arizona. Our model represents faithfully the three-dimensional geometry of boreholes at the site, and accounts directly for their storage and conductance properties by treating them as high-permeability and high-porosity cylinders of finite length and radius. It solves the airflow equations in their original nonlinear form and yields information about air permeability, air-filled porosity and dimensionless borehole storage coefficient. Some of this is difficult to accomplish with analytical type-curves. Air permeability values obtained by our inverse method agree well with those obtained by steady-state and type-curve analyses. PMID:11554246

Vesselinov, V V; Neuman, S P

2001-01-01

314

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

315

Single-Pass Flow Through (SPFT) Testing of Fluidized-Bed Steam Reforming (FBSR) Waste Forms  

SciTech Connect

Two samples of fluidized-bed steam reforming (FBSR) mineral waste form product were subjected to single-pass flow-through (SPFT) testing. Sample LAW 1123 resulted from pilot-scale FBSR processing with a Hanford Envelope A low-activity waste (LAW) simulant. Sample SBW 1173 resulted from pilot-scale FBSR processing with an Idaho National Laboratory (INL) simulant commonly referred to as sodium-bearing waste (SBW). The pilot-scale waste forms were made at the Science and Technology Applications Research (STAR) facility in Idaho Falls, Idaho. The durability of the two FBSR waste forms was assessed via the SPFT test in this study. Both samples were multiphase mineral waste forms, so the SPFT test results provide an overall release rate from the multiple mineral species in each sample and are dependent on the amount of each phase present and the mineralogy of the phases present. SPFT testing was performed at temperatures of 25, 40, 70, and 90 C on LAW 1123, while SBW 1173 was only tested at 70 and 90 C. The 70 and 90 C data were compared to each other and the LAW-1123 results were compared to previous testing performed by the Pacific Northwest National Laboratory (PNNL) on a LAW Envelope C (high organic content) waste simulant. The objectives of this study were to obtain forward dissolution rate data for both STAR FBSR bed products (using SPFT tests). Also, a qualitative comparison of the FBSR bed products to a glass waste form (specifically the low-activity reference material (LRM) glass) was performed. For these comparisons, the relative surface areas of the FBSR and glass products had to be measured. Due to the more porous and irregular surface of FBSR bed products, the surface area of the bed products was determined using the Brunauer, Emmett, and Teller (BET) measurement method. The surface area of a glass is much smoother and the calculated geometric surface area is typically used for determining dissolution behavior. Presently there are no specifications or standard release rates that the FBSR tested materials have to meet, e.g. the data from the FBSR testing is normally used during subsequent Performance Assessment (PA) calculations. Since a PA calculation is not part of this study, the LAW and SBW steam reforming samples were compared to each other, to previous LAW FBSR SPFT results, and to the results from the LRM reference glass. The experimental durability data generated from this study suggests that an FBSR mineral waste form product would be an adequate alternative form to borosilicate glass. The tested FBSR mineral waste forms showed normalized release rates for matrix elements such as Si to be more than 200X slower than the LRM glass. However, further durability testing and mineral phase information is recommended to further substantiate these findings.

Lorier, T. H.; Pareizs, J. M.; Jantzen, C. M.

2005-08-15

316

Development and test of single-bore cos-ϑ Nb3Sn dipole models with cold iron yoke  

Microsoft Academic Search

Two short Nb3Sn dipole models based on a single-bore cos-theta coil with a cold iron yoke were fabricated and tested at Fermilab. This paper summarizes the details of magnet design and fabrication procedure, and reports the test results including quench performance and quench heater studies, and the magnetic measurements.

N. Andreev; G. Ambrosio; E. Barzi; R. Carcagno; D. R. Chichili; J. DiMarco; S. Feher; L. Imbasciati; V. V. Kashikhin; M. Lamm; P. J. Limon; D. Orris; P. Schlabach; C. Sylvester; M. Tartaglia; I. Terechkine; J. C. Tompkins; S. Yadav; R. Yamada; A. V. Zlobin

2002-01-01

317

Type curve analyses of pneumatic single-hole tests in unsaturated fractured tuff: Direct evidence for a porosity scale effect  

NASA Astrophysics Data System (ADS)

A large number of single- and cross-hole pneumatic injection tests have been conducted in shallow vertical and inclined boreholes in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona. Previously, direct and indirect evidence for a permeability scale effect was provided through the analysis of these tests. Direct evidence was based on the comparison of small-scale single-hole and larger-scale cross-hole test results obtained through the type curve and steady state analysis of these data separately. Indirect evidence was provided by comparing cross-hole test analyses conducted at fine and coarse scales of resolution by means of a three-dimensional numerical inverse model. The latter study also provided indirect evidence for a porosity scale effect. However, there were no small-scale porosity data from single-hole tests to directly verify this indirect evidence. This paper presents such data generated through the type curve interpretation of the recovery phase of the single-hole tests conducted at a nominal 1-m scale providing direct evidence for a porosity scale effect at the site. Statistical analysis of results revealed a strong porosity scale effect confirming an earlier finding obtained indirectly. These results also showed that (1) the injection phase of the pneumatic single-hole tests do not yield reliable estimates of porosity but the recovery phase are amenable to type curve interpretation, (2) flow dimensionality of single-hole tests at 1-m scale are three-dimensional across the site except for a few tests which exhibited two-dimensional and fracture flow behavior, (3) there is a very weak correlation between permeability and porosity, and (4) there is a lack of correlation between fracture density and both permeability and porosity.

Illman, Walter A.

2005-04-01

318

The Single-Leg-Stance Test in Parkinson’s Disease  

PubMed Central

Background Timed single-leg-stance test (SLST) is widely used to assess postural control in the elderly. In Parkinson’s disease (PD), it has been shown that an SLST around 10 seconds or below may be a sensitive indicator of future falls. However, despite its role in fall risk, whether SLST times around 10 seconds marks a clinically important stage of disease progression has largely remained unexplored. Methods A cross-sectional study where 27 people with PD were recruited and instructed to undertake timed SLST for both legs was conducted. Disease motor impairment was assessed with the Unified Parkinson’s Disease Rating Scale Part 3 (UPDRS-III). Results This study found that: 1) the SLST in people with PD shows good test-retest reliability; 2) SLST values can be attributed to two non-overlapping clusters: a low (10.4 ± 6.3 seconds) and a high (47.6 ± 11.7 seconds) value SLST group; 3) only the low value SLST group can be considered abnormal when age-matched normative SLST data are taken into account for comparison; and 4) lower UPDRS-III motor performance, and the bradykinesia sub-score in particular, are only associated with the low SLST group. Conclusion These results lend further support that a low SLST time around 10 seconds marks a clinically important stage of disease progression with significant worsening of postural stability in PD. PMID:25584104

Chomiak, Taylor; Pereira, Fernando Vieira; Hu, Bin

2015-01-01

319

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

320

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

321

Single decoupled blasthole tests and the significance of the results to presplitting and boulder busting  

SciTech Connect

The position of a major joint in relation to a blasthole has a significant effect in presplitting. Broad research into the combined effects of firing two decoupled blastholes has been performed in the past. The effects of joints simulated between two blastholes has also been evaluated. However, no attempt has been made to investigate the splitting effects produced by firing a single decoupled blasthole. This paper presents the results of such an investigation. A series of model tests was carried out in specially prepared 12 x 9 x 6 inches concrete blocks each with a 3/8 inch blasthole, loaded with 15-grain detonating cord. To simulate a semi-infinite burden similar to field presplit conditions, the blocks were lightly constrained. Before tightening the blocks, wooden spacers approximately three inches thick were placed on one end of the block to provide a free face. Additional experiments were conducted without constraints to ascertain the resulting fracture pattern in boulder blasting mode. It was found, if the blasthole is relatively near to the free face the angle of crater is greater. It was also observed that, at a distance approximately five times the diameter of the blasthole, the cratering ceases. During these tests a recurring split appeared all the way back to the abutted end of the blocks far in excess of what is expected in presplitting. This was not anticipated. An extensive investigation was undertaken to find an application in presplitting and boulder busting for this new phenomenon. It was found that when the blasthole is placed close to the abutted end of the block, it can produce a significantly longer split than when it is placed near the middle of the block. This was also verified in tests without constraints, which illustrates its potential for application in boulder blasting.

Tariq, S.M.; Worsey, P.N.; Wilson, J.W. [Univ. of Missouri, Rolla, MO (United States)

1996-12-01

322

Liquid oxygen/hydrogen testing of a single swirl coaxial injector element in a windowed combustion chamber  

NASA Astrophysics Data System (ADS)

A modular, high pressure, liquid rocket single element combustion chamber was developed at Aerojet for use with nonintrusive combustion diagnostics. The hardware is able to accommodate full-size injection elements and includes a recessed annular injector around the single element to provide a source for hot gas background flow, which reduces recirculation in the chamber and provides additional injection mass to elevate chamber pressure. Experiments are being conducted to develop the diagnostics required to characterize a single-element combustion spray field for combustion modeling, benchmark data for CFD model validation, and development of the transfer functions between single element cold flow and multielement hot fire. The latter task is being pursued using an injector element identical to elements that had been previously cold-flow tested in single element tests to ambient backpressure and hot fire tested in a multielement injector. Preliminary tests conducted to date without hydrogen flowing through the annular coaxial orifice of the single element show the general flow characteristics of a reacting, unconfined, liquid oxygen hollow cone swirl spray.

Hulka, J.; Makel, D.

1993-06-01

323

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

324

Measurement of Surface-Mediated Ca(2+) Transients on the Single-Cell Level in a Microfluidic Lab-on-a-Chip Environment.  

PubMed

Understanding the dynamics of signal transduction processes that are induced by cell-cell or cell-surface interactions requires the physical stimulation of the cells of interest on a single-cell level and without any ill-defined contacting of their cell membrane. However, standard cell culture techniques are inapplicable for this task as they do not provide cell and particle handling at sufficiently high spatial and temporal resolution and are limited to ensemble measurements. Here, we present a novel process line for the individual stimulation of single cells with bioactive surfaces, like other cells or particles, and the simultaneous analysis of the induced cytosolic calcium signals. The method is based on a microfluidic lab-on-a-chip environment that allows for contactless cell and particle handling by dielectrophoretic forces. PMID:25563189

Kirschbaum, Michael; Jaeger, Magnus S; Duschl, Claus

2015-01-01

325

Minimized Transient and Steady-State Cross Regulation in 55-nm CMOS Single-Inductor Dual-Output (SIDO) Step-Down DC-DC Converter  

Microsoft Academic Search

A single-inductor dual-output (SIDO) step-down DC-DC converter with continuous conduction mode (CCM) oper- ation is proposed to achieve an area-efficient power management module. The low-voltage energy distribution controller (LV-EDC) can simultaneously guarantee good voltage regulation and low output voltage ripple. With the proposed dual-mode energy de- livery methodology, cross regulation in steady-state output voltage ripple, which is rarely discussed, and

Yu-Huei Lee; Tzu-Chi Huang; Yao-Yi Yang; Wen-Shen Chou; Ke-Horng Chen; Chen-Chih Huang; Ying-Hsi Lin

2011-01-01

326

Fracture trace map and single-well aquifer test results in a carbonate aquifer in Berkeley County, West Virginia  

USGS Publications Warehouse

These data contain information on the results of single-well aquifer tests, lineament analysis, and a bedrock geologic map compilation for the low-lying carbonate and shale areas of eastern Berkeley County, West Virginia. Efforts have been initiated by management agencies of Berkeley County in cooperation with the U.S. Geological Survey to further the understanding of the spatial distribution of fractures in the carbonate regions and their correlation with aquifer properties. This report presents transmissivity values from about 200 single-well aquifer tests and a map of fracture-traces determined from aerial photos and field investigations. Transmissivity values were compared to geologic factors possibly affecting its magnitude.

McCoy, Kurt J.; Podwysocki, Melvin H.; Crider, E. Allen; Weary, David J.

2005-01-01

327

Single-Event Effects Ground Testing and On-Orbit Rate Prediction Methods: The Past, Present and Future  

NASA Technical Reports Server (NTRS)

Over the past 27 years, or so, increased concern over single event effects in spacecraft systems has resulted in research, development and engineering activities centered around a better understanding of the space radiation environment, single event effects predictive methods, ground test protocols, and test facility developments. This research has led to fairly well developed methods for assessing the impact of the space radiation environment on systems that contain SEE sensitive devices and the development of mitigation strategies either at the system or device level.

Reed, Robert A.; Kinnison, Jim; Pickel, Jim; Buchner, Stephen; Marshall, Paul W.; Kniffin, Scott; LaBel, Kenneth A.

2003-01-01

328

Racial/ethnic and gender differences among older adults in nonmonogamous partnerships, time spent single, and HIV testing  

PubMed Central

Background A higher frequency of nonmonogamy, due in part to lower marriage prevalence, may contribute to elevated HIV/STD rates among older Blacks. Methods To examine race and gender differences in nonmonogamy, time spent single (i.e., not married or cohabiting), and HIV testing in older adults, we analyzed U.S. population-based data from the 2005-06 National Social Life, Health, and Aging Project (NSHAP) for 2,825 heterosexual participants ages 57-85 years. Results Blacks spent greater portions of their adult lives single than did Hispanics or Whites and were far more likely to report recent nonmonogamous partnerships (23.4% vs. 10.0% and 8.2%). Among individuals reporting sex in the prior 5 years, nonmonogamous partnerships were strongly associated with time spent single during the period. Control for time spent single and other covariates reduced the association of Black race with nonmonogamous partnerships for men but increased it for women. Less than 20% reported ever testing for HIV; less than 6% had been recommended testing by a provider. Testing rates, highest in Black men and White women, differed little by history of nonmonogamous partnerships within gender strata. Conclusions Singlehood helps to explain higher nonmonogamous partnership rates in older Black men but not older Black women. Older adults rarely receive or are recommended HIV testing, a key strategy for reducing heterosexual HIV transmission. PMID:22082721

Harawa, Nina T.; Leng, Mei; Kim, Junyeop; Cunningham, William Emery

2011-01-01

329

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

330

Comparison of the results of short-term static tests and single-pass flow-through tests with LRM glass.  

SciTech Connect

Static dissolution tests were conducted to measure the forward dissolution rate of LRM glass at 70 C and pH(RT) 11.7 {+-} 0.1 for comparison with the rate measured with single-pass flow-through (SPFT) tests in an interlaboratory study (ILS). The static tests were conducted with monolithic specimens having known geometric surface areas, whereas the SPFT tests were conducted with crushed glass that had an uncertain specific surface area. The error in the specific surface area of the crushed glass used in the SPFT tests, which was calculated by modeling the particles as spheres, was assessed based on the difference in the forward dissolution rates measured with the two test methods. Three series of static tests were conducted at 70 C following ASTM standard test method C1220 using specimens with surfaces polished to 600, 800, and 1200 grit and a leachant solution having the same composition as that used in the ILS. Regression of the combined results of the static tests to the affinity-based glass dissolution model gives a forward rate of 1.67 g/(m{sup 2}d). The mean value of the forward rate from the SPFT tests was 1.64 g/(m{sup 2}d) with an extended uncertainty of 1.90 g/(m{sup 2}d). This indicates that the calculated surface area for the crushed glass used in the SPFT tests is less than 2% higher than the actual surface area, which is well within the experimental uncertainties of measuring the forward dissolution rate using each test method. These results indicate that the geometric surface area of crushed glass calculated based on the size of the sieves used to isolate the fraction used in a test is reliable. In addition, the C1220 test method provides a means for measuring the forward dissolution rate of borosilicate glasses that is faster, easier, and more economical than the SPFT test method.

Ebert, W. L.; Chemical Engineering

2007-01-29

331

ORNL rod-bundle heat-transfer test data. Volume 2. Thermal-Hydraulic Test Facility experimental data report for test 3. 03. 6AR - transient film boiling in upflow  

Microsoft Academic Search

Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) Test 3.03.6AR. This test was conducted by members of the ORNL Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer (BDHT) Separate-Effects Program on May 21, 1980. Objective was to investigate heat transfer phenomena believed to occur in PWRs during accidents, including small and large break loss-of-coolant accidents. Test 3.03.6AR was conducted to obtain

C. B. Mullins; D. K. Felde; A. G. Sutton; S. S. Gould; D. G. Morris; J. J. Robinson

1982-01-01

332

Do LQTS Gene Single Nucleotide Polymorphisms Alter QTc Intervals at Rest and During Exercise Stress Testing?  

PubMed Central

Background The impact of harboring, genetic variants or single nucleotide polymorphisms (LQT-PM) on the repolarization response during exercise and recovery is unknown. Objective To assess the QTc interval adaptation during exercise stress testing (EST) in children with LQT polymorphisms compared to a group of age and gender matched normal controls. Methods One-hundred and forty-eight patients were age and gender matched into two groups: LQT-PM and control. Each patient underwent a uniform exercise protocol employing a cycle ergometer followed by a 9 minute recovery phase with continuous 12-lead electrocardiogram (ECG) monitoring. Intervals (RR, QT and QTc) at rest (supine), peak exercise and in recovery (1, 3, 5, 7, and 9 minutes) were measured. Results Forty three patients were positive for LQT-PM and the control group consisted of 105 patients. A total of 83 SNPs were identified: SCN5A n=31 (37%), KCNE1 n=29 (35%), KCNH2 n=20 (24%), KCNQ1 n=2 (2%) and KCNE2 n=1 (1%). The QTc interval measurements of the LQT-PM were longer at rest, peak exercise and all phases of recovery when compared to the control group. Neither group demonstrated abnormal QTc interval adaptation in response to exercise. Patients with homozygous SNPs had longer resting QTc intervals when compared to patients with only heterozygous SNPs (435±23 ms vs 415±20 ms respectively, P-value <0.006). Conclusions Individuals with LQT-PM may have longer QTc intervals at rest as well as at peak exercise and all phases of the recovery period compared to normal controls. Additionally, subjects with homozygous SNPs had longer resting QTc intervals when compared to those with only heterozygous SNPs. PMID:23714088

Aziz, Peter F; Wieand, Tammy S; Ganley, Jamie; Henderson, Jacqueline; McBride, Michael; Shah, Maully J

2015-01-01

333

Assessment of the sensitivity of the gamma-interferon test and the single intradermal comparative cervical test for the diagnosis of bovine tuberculosis under field conditions.  

PubMed

SUMMARY In some French départements, the eradication of bovine tuberculosis is incomplete and usual skin tests [single intradermal tuberculin test (SIT) and single intradermal comparative cervical test (SICCT)] have poor specificity due to cross-reactions with non-pathogenic mycobacteria, causing economic losses. In Côte d'Or (Burgundy, France), an experimental serial testing scheme based on the combination of SICCT and gamma-interferon (IFN-?) tests has been initiated in order to shorten the interval between suspicion and its invalidation in herds with false-positive results to skin tests. Our aim was to assess the scheme's sensitivity and to compare it to the sensitivity of the screening scheme recommended by the European Commission. Our study included 1768 animals from Côte d'Or. The sensitivities of both schemes were estimated using a Bayesian approach. The individual sensitivity of the IFN-? test [88·1%, 95% credibility interval (CrI) 72·8-97·5] was not significantly different from individual SICCT sensitivity (80·3%, 95% CrI 61·6-98·0) and individual SIT sensitivity (84·2%, 95% CrI 59·0-98·2). The individual specificity of the IFN-? test was 62·3% (95% CrI 60·2-64·5). No significant difference could be demonstrated between the sensitivities of the serial testing scheme used in Côte d'Or (73·1%, 95% CrI 41·1-100) and the European Union serial testing scheme (70·1%, 95% CrI 31·5-100·0). PMID:24576504

Praud, A; Boschiroli, M L; Meyer, L; Garin-Bastuji, B; Dufour, B

2015-01-01

334

Effect of temperature on elastic constants and deformation behavior in shear tests of Fe30%Al single crystals  

Microsoft Academic Search

Simple shear tests of Fe-30% Al single crystals were performed in order to measure the critical resolved shear stresses (CRSS's) for {110} (111) slip and {112} (111}slip independently and without superimposed normal stresses on the slip planes. The temperature dependence of the CRSS's for slip on {110}was found to be similar to that of the CRSS's observed in compression. For

C. Hartig; M. H. Yoo; M. Koeppe; H. Mecking

1998-01-01

335

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

336

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...

337

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

338

Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies  

NASA Technical Reports Server (NTRS)

We report low-energy proton and low-energy alpha particle single-event effects (SEE) data on a 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) latches and static random access memory (SRAM) that demonstrates the criticality of using low-energy protons for SEE testing of highly-scaled technologies. Low-energy protons produced a significantly higher fraction of multi-bit upsets relative to single-bit upsets when compared to similar alpha particle data. This difference highlights the importance of performing hardness assurance testing with protons that include energy distribution components below 2 megaelectron-volt. The importance of low-energy protons to system-level single-event performance is based on the technology under investigation as well as the target radiation environment.

Pellish, Jonathan A.; Marshall, Paul W.; Rodbell, Kenneth P.; Gordon, Michael S.; LaBel, Kenneth A.; Schwank, James R.; Dodds, Nathaniel A.; Castaneda, Carlos M.; Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.

2014-01-01

339

Single-Locus Tests of Microsatellite Evolution: Multi-Step Mutations and Constraints on Allele Size  

Microsoft Academic Search

We evaluate some common simulation procedures as well as a recently developed likelihood method used for testing hypotheses regarding microsatellite evolution. Results from simulated data revealed that the tests for the detection of multi-step mutations in general have some power, whereas tests for the presence of constraints on the repeat number have only very limited power. The tests were applied

Rasmus Nielsen; Per J. Palsbøll

1999-01-01

340

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

341

Transient tachypnea - newborn  

MedlinePLUS

TTN; Wet lungs - newborns; Retained fetal lung fluid; Transient RDS; Prolonged transition ... Transient tachypnea is a respiratory disorder seen shortly after delivery in full-term or late preterm babies. ...

342

Transient familial hyperbilirubinemia  

MedlinePLUS

Transient familial hyperbilirubinemia is a metabolic disorder that is passed down through families. Babies with this disorder ... Transient familial hyperbilirubinemia is an inherited disorder. It occurs when the body does not properly break down ( ...

343

Transient drainage summary report  

SciTech Connect

This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage.

NONE

1996-09-01

344

Development and Preclinical Testing of a High Affinity Single Chain Antibody against (+)-Methamphetamine  

PubMed Central

Chronic or excessive (+)-methamphetamine (METH) use often leads to addiction and toxicity to critical organs like the brain. With medical treatment as a goal, a novel single chain variable fragment (scFv) against METH was engineered from anti-METH monoclonal antibody mAb6H4 (IgG, ? light chain, KD = 11 nM) and found to have similar ligand affinity (KD = 10 nM) and specificity as mAb6H4. The anti-METH scFv (scFv6H4) was cloned, expressed in yeast, purified and formulated as a naturally occurring mixture of monomer (~75%) and dimer (~25%). To test the in vivo efficacy of the scFv6H4, male Sprague Dawley rats (n=5) were implanted with 3-day sc osmotic pumps delivering 3.2 mg/kg/day METH. After reaching steady-state METH concentrations, an i.v. dose of scFv6H4 (36.5 mg/kg, equimolar to the METH body burden) was administered along with a [3H]-scFv6H4 tracer. Serum pharmacokinetic (PCKN) analysis of METH and [3H]-scFv6H4 showed that the scFv6H4 caused an immediate 65-fold increase in the METH concentrations and a 12-fold increase in the serum METH area under the concentration-time curve from 0–480 min after scFv6H4 administration. The scFv6H4 monomer was quickly cleared or converted to multivalent forms with an apparent t1/2?z of 5.8 min. In contrast, the larger scFv6H4 multivalent forms (dimers, trimers, etc.) showed a much longer t1/2?z (228 min), and the significantly increased METH serum molar concentrations correlated directly with scFv6H4 serum molar concentrations. Considered together these data suggested that the scFv6H4 multimers (and not the monomer) were responsible for the prolonged redistribution of METH into the serum. PMID:18192498

Peterson, Eric C.; Laurenzana, Elizabeth M.; Atchley, William T.; Hendrickson, Howard; Owens, S. Michael

2009-01-01

345

Single pressure vessel life test update [Ni-H2 aerospace batteries  

Microsoft Academic Search

Eagle-Picher Technologies (EPT) nickel-hydrogen batteries and battery cells have been subjected to many and vaned life cycle tests. Both real time and accelerated tests in low Earth orbit as well as geosynchronous Orbit test regimes have been performed. In most cases, these tests attempt to represent the on-orbit charge\\/discharge profile of the application as closely as possible, as well as

J. Dermott; C. Guilfoyle

2002-01-01

346

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

347

Single Group, Pre- and Post-Test Research Designs: Some Methodological Concerns  

ERIC Educational Resources Information Center

This article provides two illustrations of some of the factors that can influence findings from pre- and post-test research designs in evaluation studies, including regression to the mean (RTM), maturation, history and test effects. The first illustration involves a re-analysis of data from a study by Marsden (2004), in which pre-test scores are…

Marsden, Emma; Torgerson, Carole J.

2012-01-01

348

Transient oxidation of NiAl  

Microsoft Academic Search

The transient oxidation stage of single crystal (001)NiAl was investigated using scanning electron microscopy, transmission electron microscopy, electron diffraction and high resolution electron microscopy. (001)NiAl was oxidized in air at 950°C for 50h in order to produce transient forms of alumina on the surface. After oxidation, an oxide scale with plate-like surface morphology formed. The platelets on the surface of

J. C. Yang; E. Schumann; I. Levin; M. Rühle

1998-01-01

349

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

350

Perturbations for transient acceleration  

SciTech Connect

According to the standard ?CDM model, the accelerated expansion of the Universe will go on forever. Motivated by recent observational results, we explore the possibility of a finite phase of acceleration which asymptotically approaches another period of decelerated expansion. Extending an earlier study on a corresponding homogeneous and isotropic dynamics, in which interactions between dark matter and dark energy are crucial, the present paper also investigates the dynamics of the matter perturbations both on the Newtonian and General Relativistic (GR) levels and quantifies the potential relevance of perturbations of the dark-energy component. In the background, the model is tested against the Supernova type Ia (SNIa) data of the Constitution set and on the perturbative level against growth rate data, among them those of the WiggleZ survey, and the data of the 2dFGRS project. Our results indicate that a transient phase of accelerated expansion is not excluded by current observations.

Vargas, Cristofher Zuñiga; Zimdahl, Winfried [Universidade Federal do Espírito Santo, Departamento de Física, Av. Fernando Ferrari, 514, Campus de Goiabeiras, CEP 29075-910, Vitória, Espírito Santo (Brazil); Hipólito-Ricaldi, Wiliam S., E-mail: win_unac@hotmail.com, E-mail: hipolito@ceunes.ufes.br, E-mail: winfried.zimdahl@pq.cnpq.br [Universidade Federal do Espírito Santo, Departamento de Ciências Naturais, Grupo de Física Teórica, Rodovia BR 101 Norte, km 60, Campus de São Mateus, CEP 29932-540, São Mateus, Espírito Santo (Brazil)

2012-04-01

351

Line transients with corona  

SciTech Connect

This paper investigates the effect of corona on the electromagnetic transients along high voltage overhead lines. A method is presented to simulate the line by dividing it into a number of sections connected in cascade. For {ital n} line sections, the number of the unknown variables is 2{ital n} + 1. The method allows any waveform of the exciting voltage function, as well as any impedance loading condition. The corona is represented by voltage-dependent shunt current sources. A systematic way for writing a sufficient number of differential equations is shown. For their solution, a digital computer subroutine based on the Runge--Kutta--Verner method was used. An artificial frequency-dependent damping by means of linear resistors was used to suppress the Gibb's oscillations in the solution. The proposed method is applied to study the transients on a 40 km high voltage line with 30-ft flat phase spacing and a single 1.4 inch ACSR conductor per phase. The exciting voltage has a double-exponential impulse waveform. Solutions are given for three values of resistive loads Z{sub {ital c}}2Z{sub {ital c}} and Z{sub {ital c}}/2, where Z{sub {ital c}} is the line surge impedance. The results of two interesting cases of inductive and capacitive loads are also given. Physical interpretations for the different solutions are given. Also, the current-voltage duality between inductive and capacitive loads is recognized. The corona was found to attenuate and distort the travelling waves. For example, during one wave excursion, the reduction of the current wave peaks can reach values as high as 8.5%. The effect is more noticeable in the current than in the voltage waves. As expected, it increases also with the line corona losses. The effect of the increase of the line effective capacitance due to the corona discharge is also demonstrated.

Saied, M.M.; Safar, Y.A.; Salama, M.H. (Kuwait Univ. (Kuwait))

1987-01-01

352

100-liter transient transfection.  

PubMed

This is the first report of two successful 100 l scale transienttransfections in a standard stirred bioreactor. More than half a gram of a monoclonal antibody (IgG) were produced in less than 10 days using a technology called large-scale transient gene expression(LS-TGE). Suspension adapted HEK 293 EBNA SF cells were transfectedwithin a 150 l (nominal) bioreactor by a modified calcium phosphateco-precipitation method with more than 75 mg of plasmid DNA per run.A mixture of three different plasmids, one encoding for the heavychain of a human recombinant immunoglobulin, the other for the corresponding light chain and a third one for the green fluorescent protein (GFP, 2-4% of DNA in transfection cocktail)were co-transfected. The GFP vector was chosen to monitor transfection efficiency. Expression of GFP could be registered asearly as 20 h after DNA addition, using fluorescence microscopy. We demonstrate that transient transfection can be done at the100 l scale, thus providing a new tool to produce hundreds of milligrams or even gram amounts of recombinant protein. Akey advantage of LS-TGE resides in its speed. In the presentedcases, the entire production process for the synthesis of halfa gram of a recombinant antibody, including DNA preparationand necessary expansion of cells prior to transfection, wasexecuted in less than a month. Having an established transfection/expression process allows to run productioncampaigns for any given protein, within one facility, with onesingle host cell line and therefore only one single seed train. Without any need to create and maintain stable cell lines, expression of new r-proteins is not only faster and more economical but also more flexible. PMID:19003082

Girard, Philippe; Derouazi, Madiha; Baumgartner, Gwendoline; Bourgeois, Michaela; Jordan, Martin; Jacko, Barbara; Wurm, Florian M

2002-01-01

353

Comparison of modal test results - Multipoint sine versus single-point random. [for Mariner Jupiter/Saturn spacecraft  

NASA Technical Reports Server (NTRS)

The Mariner Jupiter/Saturn (MJS) spacecraft was subjected to the traditional multipoint sine dwell (MPSD) modal test using 111 accelerometer channels, and also to single-point random (SPR) testing using 26 accelerometer channels, and the two methods are compared according to cost, schedule, and technical criteria. A measure of comparison between the systems was devised in terms of the cumulative difference in the kinetic energy distribution of the common accelerometers. The SPR and MPSD method show acceptable agreement with respect to frequencies and mode damping. The merit of the SPR method is that the excitation points are minimized and the test article can be committed to other uses while data analysis is performed. The MPSD approach allows validity of the data to be determined as the test progresses. Costs are about the same for the two methods.

Leppert, E. L.; Lee, S. H.; Day, F. D.; Chapman, P. C.; Wada, B. K.

1976-01-01

354

Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data  

SciTech Connect

In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data.

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

1990-05-01

355

First test of SP2: A novel active neutron spectrometer condensing the functionality of Bonner spheres in a single moderator  

NASA Astrophysics Data System (ADS)

The NESCOFI@BTF (2011-2013) international collaboration was established to develop realtime neutron spectrometers to simultaneously cover all energy components of neutron fields, from thermal up to hundreds MeV. This communication concerns a new spherical spectrometer, called SP^2, which condenses the functionality of an Extended Range Bonner Sphere Spectrometer (ERBSS) into a single moderator embedding multiple active thermal neutron detectors. The possibility of achieving the complete spectrometric information in a single exposure constitutes a great advantage compared to the ERBSS. The first experimental test of the instrument, performed with a reference 241Am-Be source in different irradiation geometries, is described. The agreement between observed and simulated response is satisfactory for all tested geometries.

Bedogni, R.; Bortot, D.; Buonomo, B.; Esposito, A.; Gómez-Ros, J. M.; Introini, M. V.; Lorenzoli, M.; Pola, A.; Sacco, D.

2014-12-01

356

Standard practice for measurement of the glass dissolution rate using the single-pass flow-through test method  

E-print Network

1.1 This practice describes a single-pass flow-through (SPFT) test method that can be used to measure the dissolution rate of a homogeneous silicate glass, including nuclear waste glasses, in various test solutions at temperatures less than 100°C. Tests may be conducted under conditions in which the effects from dissolved species on the dissolution rate are minimized to measure the forward dissolution rate at specific values of temperature and pH, or to measure the dependence of the dissolution rate on the concentrations of various solute species. 1.2 Tests are conducted by pumping solutions in either a continuous or pulsed flow mode through a reaction cell that contains the test specimen. Tests must be conducted at several solution flow rates to evaluate the effect of the flow rate on the glass dissolution rate. 1.3 This practice excludes static test methods in which flow is simulated by manually removing solution from the reaction cell and replacing it with fresh solution. 1.4 Tests may be conducted wit...

American Society for Testing and Materials. Philadelphia

2010-01-01

357

Using energy balances for processing the results from tests of a single-shaft combined-cycle power plant  

NASA Astrophysics Data System (ADS)

Application of the balance method for dividing the overall power output produced by a single-shaft combined-cycle power plant between the steam turbine and gas turbine unit is considered. It is shown that the method can be used for obtaining trustworthy results of thermal tests. The effect of air flowrate taken for gas turbine cooling purposes on the gas turbine unit parameters and indicators is estimated.

Ol'khovskii, G. G.

2012-09-01

358

Non-Fickian dispersion in porous media: 1. Multiscale measurements using single-well injection withdrawal tracer tests  

Microsoft Academic Search

We present a set of single-well injection withdrawal tracer tests in a paleoreef porous reservoir displaying important small-scale heterogeneity. An improved dual-packer probe was designed to perform dirac-like tracer injection and accurate downhole automatic measurements of the tracer concentration during the recovery phase. By flushing the tracer, at constant flow rate, for increasing time duration, we can probe distinctly different

P. Gouze; T. Le Borgne; R. Leprovost; G. Lods; T. Poidras; P. Pezard

2008-01-01

359

Race, Gender, Single-Mother Households, and Delinquency: A Further Test of Power-Control Theory  

ERIC Educational Resources Information Center

Using power-control theory as the theoretical framework, the present study examines the gender gap in delinquency for White and African American youth from single-mother households. The research is driven by the need to focus more attention on understanding how delinquency theories apply across different racial groups. Results from both bivariate…

Mack, Kristin Y.; Leiber, Michael J.

2005-01-01

360

Crack detection in single-crystalline silicon wafers using impact testing  

Microsoft Academic Search

This paper presents acoustic measurements obtained by mechanically exciting vibratory modes in single-crystalline silicon wafers with hairline periphery cracks of different type and location. The data presented shows a dependence of natural frequencies, peak amplitudes and damping levels of four audio vibration modes in the frequency range up to 1000Hz on crack type and crack location. Data from defective wafers

C. Hilmersson; D. P. Hess; W. Dallas; S. Ostapenko

2008-01-01

361

Single Event Upset tests of the 0.25 m version of the Atlas TRT DTMROC.  

E-print Network

-s chip and to assess the implications of residual front-end failures on the TRT read-out system during irradiation is virtually unrestricted by means of an x-y positioning shuttle. The sample holder identical conditions. The irradiation was performed as two sets, first a single TB4 board and then three TB4

Evans, Hal

362

Model refinement using transient response  

SciTech Connect

A method is presented for estimating uncertain or unknown parameters in a mathematical model using measurements of transient response. The method is based on a least squares formulation in which the differences between the model and test-based responses are minimized. An application of the method is presented for a nonlinear structural dynamic system. The method is also applied to a model of the Department of Energy armored tractor trailer. For the subject problem, the transient response was generated by driving the vehicle over a bump of prescribed shape and size. Results from the analysis and inspection of the test data revealed that a linear model of the vehicle`s suspension is not adequate to accurately predict the response caused by the bump.

Dohrmann, C.R.; Carne, T.G.

1997-12-01

363

Aligned and suspended fiber force probes for drug testing at single cell resolution.  

PubMed

The role of physical forces in disease onset and progression is widely accepted and this knowledge presents an alternative route to investigating disease models. Recently, numerous force measurement techniques have been developed to probe single and multi-cell behavior. While these methods have yielded fundamental insights, they are yet unable to capture the fibrous extra-cellular matrix biophysical interactions, involving parameters of curvature, structural stiffness (N m(-1)), alignment and hierarchy, which have been shown to play key roles in disease and developmental biology. Using a highly aggressive glioma model (DBTRG-05MG), we present a platform technology to quantify single cell force modulation (both inside-out and outside-in) with and without the presence of a cytoskeleton altering drug (cytochalasin D) using suspended and aligned fiber networks (nanonets) beginning to represent the aligned glioma environment. The nanonets fused in crisscross patterns were manufactured using the non-electrospinning spinneret based tunable engineering parameters technique. We demonstrate the ability to measure contractile single cell forces exerted by glioma cells attached to and migrating along the fiber axis (inside-out). This is followed by a study of force response of glioma cells attached to two parallel fibers using a probe deflecting the leading fiber (outside-in). The forces are calculated using beam deflection within the elastic limit. Our data shows that cytochalasin D compromises the spreading area of single glioma cells, eventually decreasing their 'inside-out' contractile forces, and 'outside-in' force response to external strain. Most notably, for the first time, we demonstrate the feasibility of using physiologically relevant aligned fiber networks as ultra-sensitive force (?nanoNewtons) probes for investigating drug response and efficacy in disease models at the single cell resolution. PMID:25264874

Sharma, Puja; Kim, AhRam; Gill, Amritpal; Wang, Ji; Sheets, Kevin; Behkam, Bahareh; Nain, Amrinder S

2014-12-01

364

[Transient amnesia in the elderly].  

PubMed

The two main aetiologies of transient amnesia in the elderly are idiopathic transient global amnesia (TGA) and iatrogenic or toxic amnesia. Vascular and epileptic amnesia are less common. According to the literature, transient psychogenic amnesia, which is a frequent cause of amnesia at age 30 to 50, is very rare in the elderly. TGA is the prototypical picture of transient amnesia. It occurs more often after age 50, with no identified cause, even if some authors accept emotional stress or minor head trauma as occasional precipitants. The mechanism of TGA remains a matter of discussion. It may be the consequence of a spreading depression similar to that described in migraine with aura, but other arguments support an ischemic mechanism. Iatrogenic amnesias are mainly caused by benzodiazepines (BZs) or anticholinergics. The former may occur in a non-anxious subject, who is not a usual consumer of BZ and takes a single dose. The latter are more often due to a hypersensitivity to anticholinergic drugs, in particular in patients presenting with a covert, incipient Alzheimer's disease. A vascular origin must be considered when amnesia is accompanied by other neurological symptoms, and when the regression of the amnesic disorder is slow, lasting several days. It results from lesions involving various mechanisms and locations, mainly subcortical. Partial seizures, most often mesio-temporal, more rarely frontal, may be the cause of transient amnesia in the elderly, in the absence of a past history of epilepsy. The red flag supportive of an epileptic origin is the repetition of stereotyped amnesic episodes. EEG demonstration of seizures may be difficult and the response to antiepileptic drugs effective on partial seizures is usually good. PMID:16556516

Sellal, François

2006-03-01

365

Responses of aquatic insects to Cu and Zn in stream microcosms: understanding differences between single species tests and field responses.  

PubMed

Field surveys of metal-contaminated streams suggest that some aquatic insects, particularly mayflies (Ephemeroptera) and stoneflies (Plecoptera), are highly sensitive to metals. However, results of single species toxicity tests indicate these organisms are quite tolerant, with LC50 values often several orders of magnitude greater than those obtained using standard test organisms (e.g., cladocerans and fathead minnows). Reconciling these differences is a critical research need, particularly since water quality criteria for metals are based primarily on results of single species toxicity tests. In this research we provide evidence based on community-level microcosm experiments to support the hypothesis that some aquatic insects are highly sensitive to metals. We present results of three experiments that quantified effects of Cu and Zn, alone and in combination, on stream insect communities. EC50 values, defined as the metal concentration that reduced abundance of aquatic insects by 50%, were several orders of magnitude lower than previously published values obtained from single species tests. We hypothesize that the short duration of laboratory toxicity tests and the failure to evaluate effects of metals on sensitive early life stages are the primary factors responsible for unrealistically high LC50 values in the literature. We also observed that Cu alone was significantly more toxic to aquatic insects than the combination of Cu and Zn, despite the fact that exposure concentrations represented theoretically similar toxicity levels. Our results suggest that water quality criteria for Zn were protective of most aquatic insects, whereas Cu was highly toxic to some species at concentrations near water quality criteria. Because of the functional significance of aquatic insects in stream ecosystems and their well-established importance as indicators of water quality, reconciling differences between field and laboratory responses and understanding the mechanisms responsible for variation in sensitivity among metals and metal mixtures is of critical importance. PMID:23734565

Clements, William H; Cadmus, Pete; Brinkman, Stephen F

2013-07-01

366

Transient excitons at metal surfaces  

NASA Astrophysics Data System (ADS)

Excitons, electron-hole pairs bound by the Coulomb potential, are the fundamental quasiparticles of coherent light-matter interaction relevant for processes such as photosynthesis and optoelectronics. The existence of excitons in semiconductors is well established. For metals, however, although implied by the quantum theory of the optical response, experimental manifestations of excitons are tenuous owing to screening of the Coulomb interaction taking place on timescales of a few femtoseconds. Here we present direct evidence for the dominant transient excitonic response at a Ag(111) surface, which precedes the full onset of screening of the Coulomb interaction, in the course of a three-photon photoemission process with ~15 fs laser pulses. During this transient regime, electron-hole pair Coulomb interactions introduce coherent quasiparticle correlations beyond the single-particle description of the optics of metals that dominate the multi-photon photoemission process on the timescale of screening at a Ag(111) surface.

Cui, Xuefeng; Wang, Cong; Argondizzo, Adam; Garrett-Roe, Sean; Gumhalter, Branko; Petek, Hrvoje

2014-07-01

367

Merging single-well and inter-well tracer tests into one forced-gradient dipole test, at the Heletz site within the MUSTANG project  

NASA Astrophysics Data System (ADS)

The Heletz site[1] in Israel was chosen for conducting a CO2 transport experiment within the MUSTANG project[2], whose aim is to demonstrate and validate leading-edge techniques for CCS site characterization, process monitoring and risk assessment. The major CO2 injection experiment at Heletz was supposed to be preceded and accompanied by a sequence of single-well 'push-then-pull' (SW) and inter-well (IW) tracer tests, aimed at characterizing transport properties of the storage formation, in accordance to a number of general and specific principles[3],[4]. - Instead of the rather luxurious {SW1, IW1, SW2, IW2} test sequence described in our previous work[5], we now propose a drastically economized tracer test concept, which lets the sampling stages of SW and IW tests merge into a single fluid production stage, and relies on a forced-gradient dipole flow field at any time of the overall test. Besides cost reduction, this economized design also improves on operational aspects, as well as on issues of parameter ambiguity and of scale disparity between SW and IW flow fields: (i) the new design renders SW test results more representative for the aquifer sector ('angle') actually interrogated by the IW dipole test; (ii) the new design saves time and costs on the SW test (fluid sampling for SW 'pull' now being conducted simultaneously with IW-related sampling and monitoring), while allowing for a considerably longer duration of SW 'pull' signals than had originally been intended, whose late-time tailings help improve the quantification of non-advective processes and parameters, which are of great relevance to mid- and long-term trapping mechanisms ('residual trapping', 'mineral trapping'); (iii) the quasi-simultaneous execution of fluid injection/production for the IW and SW tests considerably reduces the overall hydraulic imbalance that was originally associated with the SW test, thus preventing formation damage and supporting hydrogeomechanical stability; (iv) the new design reduces the imbalance between injected and produced fluid volumes at any time to a minimum, thus eliminating the need for large-capacity tanks (and water supply) to provide 'push' fluid for injection and to store 'pull' fluid during production within the SW test (saving on costs again). Advantages and drawbacks of this modified tracer test concept w. r. to parameter sensitivity and scale representativity are further analyzed by means of numerical simulations of tracer transport in the layered Heletz aquifer (using FEOW) alongside with closed-form approximations to tracer signals. References: [1] www.co2mustang.eu/Heletz.aspx [2] www.co2mustang.eu/ [3] Behrens H, Ghergut I, Sauter M (2010) Tracer properties, and tracer test results, part 3: modification to Shook's flow-storage diagram. Stanford Geothermal Prog Tech Reports, SGP-TR-188 [4] Ghergut I, Behrens H, Maier F, Karmakar S, Sauter M (2011) A note on 'heat exchange areas' as a target parameter for tracer SWIW tests. Stanford Geothermal Prog Tech Reports, SGP-TR-191 [5] presentations.copernicus.org/EGU2012-13549_presentation.pdf and presentations.copernicus.org/EGU2013-3683_presentation.pdf Acknowledgements: Heletz hydrostratigraphy data were provided by the MUSTANG project teams[1],[2], this project being funded by the EU under FP7 (grant no. 227286). Tracer transport modeling for IW and SW tests in layered reservoirs was conducted within the 'gebo' project ('Geothermal Energy and High-Performance Drilling', www.gebo-nds.de), funded by the Lower-Saxonian government and by Baker Hughes (Celle), Germany.

Behrens, Horst; Ghergut, Julia; Bensabat, Jac; Niemi, Auli; Licha, Tobias; Ptak, Thomas; Sauter, Martin

2014-05-01

368

Single-locus tests of microsatellite evolution: multi-step mutations and constraints on allele size.  

PubMed

We evaluate some common simulation procedures as well as a recently developed likelihood method used for testing hypotheses regarding microsatellite evolution. Results from simulated data revealed that the tests for the detection of multi-step mutations in general have some power, whereas tests for the presence of constraints on the repeat number have only very limited power. The tests were applied to population data obtained from nine different baleen whale populations. High agreement was found between results obtained using the simulation-based approach and results obtained using a likelihood ratio test. In four of the nine population samples the tests rejected the one-step mutation model. In two instances the significant deviation was due to excess of heterozygosity and in two instances to a reduced level of heterozygosity relative to the expectations under the stepwise mutation model. The former significant deviation was consistent with occasional multi-step mutations, whereas the latter may indicate the presence of constraints on the number of repeats. PMID:10196086

Nielsen, R; Palsbøll, P J

1999-04-01

369

THE DESIGN OF A SINGLE CARD TELEMETRY MODULE FOR SMART MUNITION TESTING  

Microsoft Academic Search

M\\/A-COM, Inc. has developed a miniature Tactical Telemetry Module (TTM) for medium power (500 mW and 1 W) telemetry applications. The TTM demonstrates system integration of a multi- channel PCM encoder, lower S-band transmitter, and power regulation onto a single printed wiring board (PWB). The module is smaller than a standard business card and utilizes both COTS and M\\/A-COM proprietary

Stephen Oder; Christina Dearstine; Amy Webb; John Muir; Inder Bahl; Larry Burke; Weyant Stone

370

Single event upset tests of a RISC-based fault-tolerant computer  

SciTech Connect

The project successfully demonstrated that dual lock-step comparison of commercial RISC processors is a viable fault-tolerant approach to handling SEU in space environment. The fault tolerant approach on orbit error rate was 38 times less than the single processor error rate. The random nature of the upsets and appearance in critical code section show it is essential to incorporate both hardware and software in the design and operation of fault-tolerant computers.

Kimbrough, J.R.; Butner, D.N.; Colella, N.J.; Kaschmitter, J.L.; Shaeffer, D.L.; McKnett, C.L.; Coakley, P.G.; Casteneda, C.

1996-03-23

371

Biotesting the biological effects of single-wall carbon nanotubes using bioluminescent bacteria test-system  

Microsoft Academic Search

The effect of single-wall carbon nanotubes (carbon SWNTs) on bacterial cells Escherichia coli K12 TG1 with cloned lux-operon of natural marine bacteria Photobacterium leiognathi was studied. Using atomic force microscopy (AFM), bacterial cell morphological changes were revealed and a cell viability\\u000a decrease controlled by the number of colony-forming units was registered. It was shown that prior to this we can

A. P. Zarubina; E. P. Lukashev; L. I. Deev; I. M. Parkhomenko; A. B. Rubin

2009-01-01

372

Low-speed wind-tunnel tests of single- and counter-rotation propellers  

NASA Technical Reports Server (NTRS)

A low-speed (Mach 0 to 0.3) wind-tunnel investigation was conducted to determine the basic performance, force and moment characteristics, and flow-field velocities of single- and counter-rotation propellers. Compared with the eight-blade single-rotation propeller, a four- by four- (4 x 4) blade counter-rotation propeller with the same blade design produced substantially higher thrust coefficients for the same blade angles and advance ratios. The results further indicated that ingestion of the wake from a supporting pylon for a pusher configuration produced no significant change in the propeller thrust performance for either the single- or counter-rotation propellers. A two-component laser velocimeter (LV) system was used to make detailed measurements of the propeller flow fields. Results show increasing slipstream velocities with increasing blade angle and decreasing advance ratio. Flow-field measurements for the counter-rotation propeller show that the rear propeller turned the flow in the opposite direction from the front propeller and, therefore, could eliminate the swirl component of velocity, as would be expected.

Dunham, D. M.; Gentry, G. L., Jr.; Coe, P. L., Jr.

1986-01-01

373

Bone fracture characterization under mixed-mode I+II loading using the single leg bending test.  

PubMed

Fracture under mixed-mode I+II was induced in bovine cortical bone tissue using a developed miniaturized version of the single leg bending test (SLB). Due to the difficulty in crack length monitoring in the course of the test, an equivalent crack method based on specimen compliance and beam theory was adopted as a data reduction scheme. The method was applied to the experimental results in order to obtain the Resistance curves in each loading mode. The determined fracture energy is well described by an energetic power law whose exponent is below one, which means that the linear energetic criterion is not applicable to this material. The proposed procedure was numerically validated by means of a cohesive mixed-mode I+II damage model with bilinear softening. It was concluded that the miniaturized version of the SLB test is adequate for mixed-mode I+II fracture characterization of bone for a constant mode ratio. PMID:24715503

Pereira, F A M; de Moura, M F S F; Dourado, N; Morais, J J L; Dias, M I R

2014-11-01

374

Single venom-based immunotherapy effectively protects patients with double positive tests to honey bee and Vespula venom  

PubMed Central

Background Referring to individuals with reactivity to honey bee and Vespula venom in diagnostic tests, the umbrella terms “double sensitization” or “double positivity” cover patients with true clinical double allergy and those allergic to a single venom with asymptomatic sensitization to the other. There is no international consensus on whether immunotherapy regimens should generally include both venoms in double sensitized patients. Objective We investigated the long-term outcome of single venom-based immunotherapy with regard to potential risk factors for treatment failure and specifically compared the risk of relapse in mono sensitized and double sensitized patients. Methods Re-sting data were obtained from 635 patients who had completed at least 3 years of immunotherapy between 1988 and 2008. The adequate venom for immunotherapy was selected using an algorithm based on clinical details and the results of diagnostic tests. Results Of 635 patients, 351 (55.3%) were double sensitized to both venoms. The overall re-exposure rate to Hymenoptera stings during and after immunotherapy was 62.4%; the relapse rate was 7.1% (6.0% in mono sensitized, 7.8% in double sensitized patients). Recurring anaphylaxis was statistically less severe than the index sting reaction (P = 0.004). Double sensitization was not significantly related to relapsing anaphylaxis (P = 0.56), but there was a tendency towards an increased risk of relapse in a subgroup of patients with equal reactivity to both venoms in diagnostic tests (P = 0.15). Conclusions Single venom-based immunotherapy over 3 to 5 years effectively and long-lastingly protects the vast majority of both mono sensitized and double sensitized Hymenoptera venom allergic patients. Double venom immunotherapy is indicated in clinically double allergic patients reporting systemic reactions to stings of both Hymenoptera and in those with equal reactivity to both venoms in diagnostic tests who have not reliably identified the culprit stinging insect. PMID:24004607

2013-01-01

375

Insight from simulations of single-well injection-withdrawal tracer tests on simple and complex fractures  

SciTech Connect

The single-well injection withdrawal (SWIW) test, a tracer test utilizing only one well, is proposed as a useful contribution to site characterization of fractured rock, as well as providing parameters relevant to tracer diffusion and sorption. The usual conceptual model of flow and solute transport through fractured rock with low matrix permeability involves solute advection and dispersion through a fracture network coupled with diffusion and sorption into the surrounding rock matrix. Unlike two-well tracer tests, results of SWIW tests are ideally independent of advective heterogeneity, channeling and flow dimension, and, instead, focus on diffusive and sorptive characteristics of tracer (solute) transport. Thus, they can be used specifically to study such characteristics and evaluate the diffusive parameters associated with tracer transport through fractured media. We conduct simulations of SWIW tests on simple and complex fracture models, the latter being defined as having two subfractures with altered rock blocks in between and gouge material in their apertures. Using parameters from the Aspo site in Sweden, we calculate and study SWIW tracer breakthrough curves (BTCs) from a test involving four days of injection and then withdrawal. By examining the peak concentration C{sub pk} of the SWIW BTCs for a variety of parameters, we confirm that C{sub pk} is largely insensitive to the fracture advective flow properties, in particular to permeability heterogeneity over the fracture plane or to subdividing the flow into two subfractures in the third dimension orthogonal to the fracture plane. The peak arrival time t{sub pk} is not a function of fracture or rock properties, but is controlled by the time schedule of the SWIW test. The study shows that the SWIW test is useful for the study of tracer diffusion-sorption processes, including the effect of the so-called flow-wetted surface (FWS) of the fracture. Calculations with schematic models with different FWS values are conducted and the possibility of direct in situ measurement of FWS with SWIW tests is demonstrated.

Tsang, C.-F.; Doughty, C.

2009-08-06

376

Waste characterization plan for the Hanford Site single-shell tanks. Appendix I, Test plan for sampling and analysis of ten single-shell tanks  

SciTech Connect

This appendix describes the sampling and analysis of the next ten single-shell tanks (SST) following the successful of SSTs B-201 and B-202. SST T-203 shall not be core sampled sequentially after B-201 and B-202, as originally planned, because this tank would not have provided information on tank safety issues and it contains an identical waste type as the previous two SSTs. Therefore, sampling and analysis of T-203 at the present time was considered repetitious and not an efficient utilization of the limited available resources. This test plan will outline methodology for characterization of the next ten SSTs, summarize lessons learned in the laboratory during Phase IA/IB, identify criteria for tank selection, and detail the analysis to be performed during the characterization of each tank. The sampling, analysis, and data collection, detailed by the this test plan, are being performed to support the final SST closure date of 2,018 identified in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement).

Hill, J.G.; Winters, W.I.; Simpson, B.C. [Westinghouse Hanford Co., Richland, WA (United States); Buck, J.W.; Chamberlain, P.J.; Hunter, V.L. [Pacific Northwest Lab., Richland, WA (United States)

1991-09-01

377

Testing of high-octane fuels in the single-cylinder airplane engine  

NASA Technical Reports Server (NTRS)

One of the most important properties of aviation fuels for spark-ignition engines is their knock rating. The CFR engine tests of fuels of 87 octane and above does not always correspond entirely to the actual behavior of these fuels in the airplane engine. A method is therefore developed which, in contrast to the octane number determination, permits a testing of the fuel under various temperatures and fuel mixture conditions. The following reference fuels were employed: 1) Primary fuels; isooctane and n-heptane; 2) Secondary fuels; pure benzene and synthetic benzine.

Seeber, Fritz

1940-01-01

378

Shake Table Tests of a Simplified Two-Story Single-Family House  

NSDL National Science Digital Library

This collection of video clips from the Caltech Woodframe Project shows what happens to a wood-frame house when it is shaken in the laboratory under conditions resembling those of an earthquake. There are both interior and exterior views, and also tests with furnishings in the house. The videos are available in two formats. There are also links to a description of the project, objectives of the testing, comments on building codes and standards in California, and the economic impacts to insurance, martgage lending, loss estimation, and disaster relief policies.

379

Exponential speed-up with a single bit of quantum information: Testing the quantum butterfly effect  

E-print Network

We present an efficient quantum algorithm to measure the average fidelity decay of a quantum map under perturbation using a single bit of quantum information. Our algorithm scales only as the complexity of the map under investigation, so for those maps admitting an efficient gate decomposition, it provides an exponential speed up over known classical procedures. Fidelity decay is important in the study of complex dynamical systems, where it is conjectured to be a signature of quantum chaos. Our result also illustrates the role of chaos in the process of decoherence.

David Poulin; Robin Blume-Kohout; Raymond Laflamme; Harold Ollivier

2003-10-06

380

Development and Testing of a Single Frequency Terahertz Imaging System for Breast Cancer Detection  

PubMed Central

The ability to discern malignant from benign tissue in excised human breast specimens in Breast Conservation Surgery (BCS) was evaluated using single frequency terahertz radiation. Terahertz (THz) images of the specimens in reflection mode were obtained by employing a gas laser source and mechanical scanning. The images were correlated with optical histological micrographs of the same specimens, and a mean discrimination of 73% was found for five out of six samples using Receiver Operating Characteristic (ROC) analysis. The system design and characterization is discussed in detail. The initial results are encouraging but further development of the technology and clinical evaluation is needed to evaluate its feasibility in the clinical environment. PMID:25055306

St. Peter, Benjamin; Yngvesson, Sigfrid; Siqueira, Paul; Kelly, Patrick; Khan, Ashraf; Glick, Stephen; Karellas, Andrew

2013-01-01

381

Development and testing of a single frequency terahertz imaging system for breast cancer detection.  

PubMed

The ability to discern malignant from benign tissue in excised human breast specimens in Breast Conservation Surgery (BCS) was evaluated using single frequency terahertz radiation. Terahertz (THz) images of the specimens in reflection mode were obtained by employing a gas laser source and mechanical scanning. The images were correlated with optical histological micrographs of the same specimens, and a mean discrimination of 73% was found for five out of six samples using Receiver Operating Characteristic (ROC) analysis. The system design and characterization is discussed in detail. The initial results are encouraging but further development of the technology and clinical evaluation is needed to evaluate its feasibility in the clinical environment. PMID:25055306

St Peter, Benjamin; Yngvesson, Sigfrid; Siqueira, Paul; Kelly, Patrick; Khan, Ashraf; Glick, Stephen; Karellas, Andrew

2013-07-01

382

Ris-R-1483(EN) Testing procedure for the single fiber  

E-print Network

to fiber fragmentations. Different bonding strengths between fiber and matrix result in differences is the control of the degree of adhesion between the usually more rigid fiber and the relatively ductile polymer measurement of the adhesion between a fiber and the surrounding polymer matrix. Round robin tests involving

383

IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 1 Generation of Single Input Change Test Sequences  

E-print Network

PROGRAMMABLE LOGIC CONTROLLERS (PLCs) are industrial automation components that are widely used to implement control functions, even in critical systems like power production and distribution, rail transport for Conformance Test of Programmable Logic Controllers Julien Provost, Member, IEEE, Jean-Marc Roussel, Jean

Paris-Sud XI, Université de

384

Environmental assessment: Single-stage rocket technology DC-X test program  

SciTech Connect

The National Environmental Policy Act (NEPA), the Council on Environmental Quality (CEQ) regulations implementing NEPA (40 CFR Parts 1500-1508), and U.S. Department of Defense (DoD) Directive 6050.1 direct that decision-makers take into account environmental consequences when authorizing or approving major federal actions. This environmental assessment (EA) evaluates the environmental consequences of conducting activities for the SSRT test program. The purpose of the proposed action is to provide SDIO with a suborbital, recoverable rocket (SRR) capable of lifting up to 3,000 pounds of payload to an altitude of 1.5 million feet; returning to the launch site for a precise soft landing; with the capability to launch for another mission within three to seven days. To support these requirements, the proposed action involves validation and testing of a DC-X vehicle. Component assembly of the vehicle will take place at Scaled Composites, Inc., Mojave, CA; Chicago Bridge and Iron, Cordova, AL; Pratt and Whitney, West Palm Beach, FL, Aerojet, Sacramento, CA; and McDonnell Douglas Space Systems Company, Beach, CA. Static test firing activities will occur at NASA/White Sands Test Facility Huntington (WSTF), WSMR, New Mexico, and launch activities will occur at White Sands Space Harbor (WSSH), WSMR, New Mexico. No significant impacts are anticipated to the environment at the engineering contractor facilities, NASA/WSTF, or WSSH.

Not Available

1992-06-01

385

A Single-Block TRL Test Fixture for the Cryogenic Characterization of Planar Microwave Components  

NASA Technical Reports Server (NTRS)

The High-Temperature-Superconductivity (HTS) group of the RF Technology Branch, Space Electronics Division, is actively involved in the fabrication and cryogenic characterization of planar microwave components for space applications. This process requires fast, reliable, and accurate measurement techniques not readily available. A new calibration standard/test fixture that enhances the integrity and reliability of the component characterization process has been developed. The fixture consists of 50 omega thru, reflect, delay, and device under test gold lines etched onto a 254 microns (0.010 in) thick alumina substrate. The Thru-Reflect-Line (TRL) fixture was tested at room temperature using a 30 omega, 7.62 mm (300 mil) long, gold line as a known standard. Good agreement between the experimental data and the data modelled using Sonnet's em(C) software was obtained for both the return (S(sub 11)) and insertion (S( 21)) losses. A gold two-pole bandpass filter with a 7.3 GHz center frequency was used as our Device Under Test (DUT), and the results compared with those obtained using a Short-Open-Load-Thru (SOLT) calibration technique.

Mejia, M.; Creason, A. S.; Toncich, S. S.; Ebihara, B. T.; Miranda, F. A.

1996-01-01

386

Defining Group Membership: The Impact of Multiple versus Single Ethnic/Racial Categories on Testing Practices.  

ERIC Educational Resources Information Center

At the time of registration, students taking the Scholastic Assessment Tests (SAT) voluntarily complete the Student Descriptive Questionnaire (SDQ), which asks a variety of questions, one of which asks students to choose the ethnic/racial category that describes them. choosing only one category. The SAT Program undertook two studies aimed at…

Wendler, Cathy; Feigenbaum, Miriam; Escandon, Merida

387

Wind-tunnel Tests of Eight-blade Single and Dual-rotating Propellers in the Tractor Position  

NASA Technical Reports Server (NTRS)

Tests of 10-ft. diameter, eight-blade, single - and dual - rotating propellers were conducted in 20-ft propeller research tunnel. Propellers were mounted at front end of a streamline body in spinners that covered hubs and parts of shanks. Effect of a symmetrical wing mounted in slipstream was investigated. Blade-angle settings ranged from 20 Degrees to 65 Degrees. Results indicated that dual rotation resulted in gains of from 1 to 8 percent in efficiency over single rotation for eight-blade propellers, but presence of a wing reduced gain about one-half. Greater power absorption caused by dual rotation over flight range and higher efficiency or thrust for range of take-off and climb was indicated

Gray, W.H.; Biermann, David

1941-01-01

388

Wind-Tunnel Tests of Four- and Six-Blade Single- and Dual-Rotating Tractor Propellers  

NASA Technical Reports Server (NTRS)

Test of 10-foot diameter, four and six blade single-rotating and dual-rotating propellers were conducted in the NACA propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream ranged from 20 degrees to 65 degrees setting corresponds to airplane speeds greater than 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6 percent more efficient than single-rotating ones; but, when the propellers operated in the presence of a wing, the gain was reduced by about one-half. Other advantages of dual-rotating propellers were found to include greater power absorption and greater efficiency at the low V/nD operating range of high-pitch propellers.

Biermann, David; Hartman, Edwin P

1942-01-01

389

Full-Scale Tests of 4- and 6-Blade, Single- and Dual-Rotating Propellers, Special Report  

NASA Technical Reports Server (NTRS)

Test of 10-foot diameter, 4- and 6-blade single- and dual-rotating propellers were conducted in the 20-foot propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream was investigated. The blade angles investigated ranged from 20 degrees to 65 degrees; the latter setting corresponds to airplane speeds of over 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6% more efficient than single-rotating ones; but when operating in the presence of a wing the gain was reduced about one-half. Other advantages of dual-rotating propellers were found to include greater power absorption and greater efficiency at the low V/nD operating range of high pitch propellers.

Biermann, David; Hartman, Edwin P.

1940-01-01

390

Bedload transport formulae calibration using a single measurement: testing high and low  

NASA Astrophysics Data System (ADS)

Due to the difficulty in accurately predicting bedload transport using traditional equations, bedload samples are often collected in the field and used to calibrate predictions. However, sampling bedload is time consuming and expensive. In lieu of conducting an exhaustive sampling campaign in the field, some researchers have recommended collecting one to three low flow samples in the field. This work addresses the question of whether a single bedload measurement near bankfull is more successful at calibrating a predictive equation than a low flow measurement. The Pagosa Good/Fair, Wilcock Surface-based Two Fraction, and Barry et al. General Power Equation formulae are compared using a single calibration point at low flow and then another at bankfull discharge. The comparison is conducted using 2,500 measurements from a database of a total of 8,000 available measurements. The results show that a measurement at bankfull is a better predictor than a low flow measurement, but acceptable results at low flow are provided by the Pagosa and Barry formulae. This work also recommends that sampling methodology be a consideration for formula selection. In other words, certain formulae work better for Helley-Smith samplers while others are better suited for data collected in net or pit traps. For example, the predictive curve produced by the Pagosa and Barry formulae better fit Helley-Smith data than the Wilcock, which is recommended for data collected in net or pit traps.

Hinton, D. D.; Hotchkiss, R. H.

2012-12-01

391

Test of the Cross Correlation Method for Efficient Single Crystal Diffuse Neutron Scattering with Elastic Discrimination  

NASA Astrophysics Data System (ADS)

Single crystal diffuse scattering provides a powerful probe of the complex disorder associated with many emergent phenomena of great interest. It provides a determination not only of the local distortions around a point defect but also of the length scale and morphology of short-range order on the nanoscale. However, obtaining accurate models of the local structure usually demands measurements over large volumes of reciprocal space with sufficiently high momentum and energy resolution. In order to overcome limitations of current instrumentation, we propose to utilize the cross-correlation method at pulsed neutron sources. This concept that combines the high efficiency of white-beam Laue diffraction for measuring large volumes of reciprocal space with energy discrimination produced by the use of a statistical chopper is currently being implemented in a dedicated instrument, Corelli , under construction at the Spallation Neutron Source. Here, we present our detailed investigation of the effectiveness of this method for measuring weak diffuse signals, based on full experiment simulations as well as actual measurements of the diffuse scattering from powder and single crystal samples obtained utilizing the cross correlation method on a prototype instrument.

Rosenkranz, Stephan; Castellan, John Paul; Vitt, Rich; Osborn, Raymond; Riedel, Rick; Ruiz-Rodriguez, Mariano; Funk, Loren

2013-03-01

392

Low voltage pulse injection test of a single-stage 1 MV prototype induction voltage adder cell  

NASA Astrophysics Data System (ADS)

Low voltage pulse injection tests have been done on a 1 MV prototype induction cell. The tests mainly aim at measuring azimuthal uniformity of feed currents and evaluating cell electrical parameters. Tests are conducted under two cases that the cell is fed by a single pulse and two pulses, respectively. The results indicate that, in the case of the single-point feed, the best current uniformity with an azimuthal variation of 19.3% is acquired when azimuthal lines connect to cathode plates with lower half circumferences. In the case of two-pulse synchronous feed, the current uniformity becomes better, and a current with an azimuthal variation of 11.8% is achieved. Moreover, the effects of asynchronous feed on current uniformity are also experimentally investigated. The results imply that, for given injecting pulses with the duration of 70-80 ns, a time deviation less than 30 ns could be acceptable, without obvious degradation on the feed uniformity and current addition. In addition, the influences of the current uniformity and amounts of feed pulses on cell equivalent inductances are evaluated. The experiment results show that, the equivalent inductance would nearly keep a value of 130 nH as the current variation is less than 50%. However, the extreme asymmetry of feed currents or the increase of amounts of feed pulses would produce additional inductance.

Wei, Hao; Sun, Fengju; Liang, Tianxue; Yin, Jiahui; Dang, Tengfei; Zeng, Jiangtao; Cong, Peitian; Qiu, Aici

2014-08-01

393

Testing of polyimide second-stage rod seals for single-state applications in advanced aircraft hydraulic systems  

NASA Technical Reports Server (NTRS)

Machined polyimide second-stage rod seals were evaluated to determine their suitability for single-stage applications where full system pressure acts on the upstream side of the seal. The 6.35-cm (2.5-in.) K-section seal was tested in impulse screening tests where peak pressure was increased in 3.448-MPa (500-psi) increments each 20,000 cycles. Seal failure occurred at 37.92 MPa (5,500 psi), indicating a potential for acceptability in a 27.58-MPa (4,000-psi) system. Static pressurization for 600 sec at pressures in excess of 10.34 MPa (1,500 psi) revealed structural inadequacy of the seal cross section to resist fracture and extrusion. Endurance testing showed the seals capable of at least 65,000 1.27-cm (0.5-in.) cycles at 450 K (350 F) without leakage. It was concluded that the second-stage seals were proven to be exceptional in the 1.379-MPa (200-psi) applications for which they were designed, but polyimide material properties are not adequate for use in this design at pressure loading equivalent to that present in single-stage applications.

Waterman, A. W.

1977-01-01

394

Early Effect of Single-dose Sitagliptin Administration on Gastric Emptying: Crossover Study Using the 13C Breath Test  

PubMed Central

Background/Aims The gastrointestinal motility effects of endogenous incretin hormones enhanced by dipeptidyl peptidase-IV (DPP-IV) inhibitors have not yet been sufficiently investigated. The aim of this study was to determine whether single pre-prandial sitagliptin, the DPP-IV inhibitor, administration might have an effect on the rate of liquid gastric emptying using the 13C-acetic acid breath test. Methods Ten healthy male volunteers participated in this randomized, two-way crossover study. The subjects fasted for overnight and were randomly assigned to receive 50 mg sitagliptin 2 hours before ingestion of the liquid test meal (200 kcal per 200 mL, containing 100 mg 13C-acetate) or the test meal alone. Under both conditions, breath samples were collected for 150 minutes following the meal. Liquid gastric emptying was estimated by the values of the following parameters: the time required for 50% emptying of the labeled meal (T1/2), the analog to the scintigraphy lag time for 10% emptying of the labeled meal (Tlag), the gastric emptying coefficient and the regression-estimated constants (? and ?), calculated by using the 13CO2 breath excretion curve using the conventional formulae. The parameters between the 2 test conditions were compared statistically. Results No significant differences in the calculated parameters, including T1/2, Tlag, gastric emptying coefficient or ? and ?, were observed between the 2 test conditions. Conclusions The present study revealed that single-dose sitagliptin intake had no significant influence on the rate of liquid gastric emptying in asymptomatic volunteers. PMID:23667754

Nonaka, Takashi; Sekino, Yusuke; Iida, Hiroshi; Yamada, Eiji; Ohkubo, Hidenori; Sakai, Eiji; Higurashi, Takuma; Hosono, Kunihiro; Endo, Hiroki; Koide, Tomoko; Takahashi, Hirokazu; Fujita, Koji; Yoneda, Masato; Goto, Ayumu; Kusakabe, Akihiko; Kobayashi, Noritoshi; Gotoh, Eiji; Maeda, Shin; Nakajima, Atsushi; Nosaka, Chihiro

2013-01-01

395

The Radio Transient Sky  

Microsoft Academic Search

Transient radio sources are necessarily compact and usually are the locations of explosive or dynamic events, therefore offering unique opportunities for probing fundamental physics and astrophysics. In addition, short-duration transients are powerful probes of intervening media owing to dispersion, scattering, and Faraday rotation that modify the signals. While radio astronomy has an impressive record obtaining high time resolution, usually it

J. Lazio; P. S. Ray; S. Ellingson; S. Close; P. Crane; S. D. Hyman; B. A. Jacoby; W. Junor; N. E. Kassim; S. R. Kulkarni; Y. M. Pihlstrom; G. B. Taylor; D. Werthimer

2006-01-01

396

Coronal transient phenomena  

Microsoft Academic Search

Solar coronal transients, particularly those caused by flares and eruptive prominences, play a major role in the fields of solar-terrestrial physics and astrophysics. In the former field, coronal transients and their associated interplanetary disturbances are responsible for solar and galactic cosmic ray modulations, as well as planetary magnetospheric and ionospheric disturbances. In the latter field, supernovae remnants are scaled-up manifestations

M. Dryer

1982-01-01

397

Latex based, rapid and easy assay for human leptospirosis in a single test format.  

PubMed

Leptospirosis is an often severe disease which requires prompt treatment. Laboratory testing is required to reach a valid diagnosis. An agglutination assay for the detection of Leptospira-specific antibodies consisting of individually wrapped agglutination cards containing a stable, dried detection reagent is evaluated. The assay is simply performed by suspending the dried reagent with a drop of serum. The result is obtained within 30 s. The sensitivity of the assay varied with the stage of the disease and was 72.3% for samples collected during the first 10 days of the illness and 88.2% for samples collected at a later stage. The specificity was 93.9% and 89.8%, respectively. These characteristics make the test ideal for use in areas where the disease is common and where laboratory support is not routinely available. PMID:11251907

Smits, H L; Chee, H D; Eapen, C K; Kuriakose, M; Sugathan, S; Gasem, M H; Yersin, C; Sakasi, D; Lai-A-Fat, R F; Hartskeerl, R A; Liesdek, B; Abdoel, T H; Goris, M G; Gussenhoven, G C

2001-02-01

398

AN EXPERIMENTAL TEST OF SUPERRADIANCE IN A SINGLE PASS SEEDED FEL.  

SciTech Connect

Superradiance and nonlinear evolution of a FEL pulse in a single-pass FEL were experimentally demonstrated at the National Synchrotron Light Source (NSLS) Source Development Laboratory (SDL). The experiment was performed using a 1.5 ps high-brightness electron beam and a 100fs Ti:Sapphire seed laser. The seed laser and electron beam interact in the 10 meter long NISUS undulator with a period of 3.89 cm. The FEL spectrum, energy and pulse length along the undulator were measured. FEL saturation was observed, and gain of more the 200 (relative to seed laser) was measured. Both FEL spectrum widening and pulse length shortening were observed; FEL pulses as short as 65 fs FWHM were measured. The superradiance and nonlinear evolution were also simulated using the numerical code GENESIS1.3 yielding good agreement with the experimental results.

WATANABE, T.; LIU, D.; MURPHY, J.B.; ROSE, J.; SHAFTAN, T.; TSANG, T.; WANG, X.J.; YU, L.H.

2005-08-21

399

Environmental qualification: instrument transmitter temperature transient analysis. [PWR  

Microsoft Academic Search

The effects of severe containment temperature transients on safety-related instrument transmitters are analyzed using a one-dimensional slab model constructed using test data from the Westinghouse Supplemental Environmental Qualification Program. This analysis is performed using the Westinghouse COCO computer code and its subroutines to compute the temperature transient responses in the transmitter for both the Westinghouse Instrument Environmental Qualification Test Curve

T. Hsieh; R. T. Barlow; H. V. Julian

1977-01-01

400

Transient Pressure Analysis in Strip Reservoirs with Linear  

E-print Network

SGP-TR-97 Transient Pressure Analysis in Strip Reservoirs with Linear Skin Discontinuities considerations when analysing pressure draw- down and buildup tests. The changes exhibited in test results can reveal important geometrical features of the reservoir boundary. And, based on the pressure transient

Stanford University

401

Initial testing of a Compact Crystal Positioning System for the TOPAZ Single-Crystal Diffractometer at the Spallation Neutron Source  

SciTech Connect

A precise, versatile, and automated method of orienting a sub-millimeter crystal in a focused neutron beam is required for e cient operation of the TOPAZ Single Crystal Di ractometer at the Spallation Neutron Source at Oak Ridge National Laboratory. To ful ll this need, a Compact Crystal Positioning System (CCPS) has been developed in collaboration with Square One Systems Design in Jackson, Wyoming. The system incorporates a tripod design with six vacuum-compatible piezoelectric linear motors capable of < 1 m resolution. National Instruments LabVIEW provides a means of system automation while at the same time accommodating the modular nature of the SNS sample environment control software for straightforward system integration. Initial results in a cryogenic test environment will be presented, as well as results from ambient tests performed at the Advanced Photon Source at Argonne National Laboratory.

Frost, Matthew J [ORNL; Austin, Michael D [ORNL; Viola, Robert [ORNL; Thomison, Jack [ORNL; Carmen, Peter [Square One Systems Design; Hoffmann, Christina [ORNL; Miller, Echo M [ORNL; Mosier, Lisa B [ORNL; Overbay, Mark A [ORNL

2009-01-01

402

Testing of soft-oriented NiAl single crystals in simple shear  

SciTech Connect

The intermetallic NiAl has been of considerable interest recently as a prospective replacement for superalloys in turbine engines because of its higher melting point, lower density and good oxidation resistance. In addition, its B2 crystal structure is considered to have good potential for ductility enhancement due to its high symmetry and simple slip directions. Unfortunately, limited room temperature ductility has hindered the development of NiAl alloys. This is primarily due to an insufficient number of independent slip systems to satisfy Von Mises' criterion for uniform deformation. However, the presence of complex dislocation core structures has also been suggested to play a role in the deformation behavior of NiAl. At room temperature, NiAl rarely exhibits <111> slip and deforms primarily by <100> slip on either [001] or [011] type planes. Simulations of a<100> dislocations in NiAl suggest cores spread out of the observed slip plane, which is generally expected to give rise to Schmid's law violations. In addition, based on Schmid's law analysis, slip of a<100> dislocations on [100] planes has been reported to occur at lower stresses than on the more closely packed [110] planes which is unexpected from Peierls stress estimates. Furthermore, Takasugi et al. observed that in compression the critical resolved shear stresses (CRSSs) were higher than in tension for a given orientation (i.e., stress asymmetry). Therefore, it is likely that Schmid's law is not observed in NiAl and simple shear tests are needed to determine the actual critical shear stress (CSS) for deformation. In the present study, CSS values were measured for <100> slip on both [001] and [011] planes. These values are compared to CRSS values obtained from compression test using Schmid factor calculations. Prismatic punch testing was conducted to investigate the possibility of a<001>[hk0] slip in NiAl.

Duncan, A.J.; Kaufman, M.J. (Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering); Schneibel, J.H. (Oak Ridge National Lab., TN (United States). Metals and Ceramics Division)

1994-07-01

403

Transient Scrotal Hyperthermia Induces Lipid Droplet Accumulation and Reveals a Different ADFP Expression Pattern between the Testes and Liver in Mice  

PubMed Central

Background In most mammals, the testes provide a stable environment for spermatogenesis, which depends on a lower temperature than the core body temperature. It has been reported that mild testicular heating safely and reversibly suppresses spermatogenesis, and is under consideration for its potential application as a male contraceptive. Previously, we focused on the molecular mechanism of germ cell apoptosis and anti-apoptotic factors induced by heat treatment in humans and mice. However, the recovery process remains under investigation. Results In this study, we found that lipid droplets in mouse testes are dramatically increased after a brief period of scrotal hyperthermia, and gradually dissipate following temperature normalization. Analysis of the human testis proteome revealed nine proteins associated with lipid droplets. Two of them, ADFP (also known as ADRP and PLIN2) and TIP47 (also known as PLIN3) may participate in acute lipid droplet formation in mammalian testes. We show that Adfp expression is upregulated after scrotal heat treatment in mice. Surprisingly, we find Adfp lacking its 5?-UTR is observed in Adfp?1/?1 mouse testes, but is not detectable in liver. Conclusions These results reveal testis Adfp transcriptional regulation is tissue-specific, and is associated with lipid droplet accumulation induced by heat. The results also indicate that the testes could retain functional proteins through testes-specific transcriptional regulation. PMID:23056214

Liu, Mingxi; Qi, Lin; Zeng, Yan; Yang, Yang; Bi, Ye; Shi, Xiaodan; Zhu, Hui; Zhou, Zuomin; Sha, Jiahao

2012-01-01

404

Transient fault modeling and fault injection simulation  

E-print Network

An accurate transient fault model is presented in this thesis. A 7-term exponential current upset model is derived from the results of a device-level, 3-dimensional, single-event-upset simulation. A curve-fitting algorithm is used to extract...

Yuan, Xuejun

2012-06-07

405

Field test of single well DNAPL characterization using alcohol injection/extraction  

SciTech Connect

Soils and groundwater beneath an abandoned process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLs, or dense non-aqueous phase liquids. Technologies targeted at efficient characterization or removal of DNAPL are not currently proven. The authors performed injection/extraction characterization tests in six existing wells in A/M Area. Water concentrations for TCE and/or PCE in these wells ranged from 0% to 100% of solubility. For each test, small amounts of solubilizing solution were used to try to confirm or deny the presence or absence of DNAPL in the immediate vicinity of the well screen.

Jerome, K.M.; Looney, B.B.; Rhoden, M.L.; Riha, B.; Burdick, S. [Westinghouse Savannah River Co., Aiken, SC (United States)

1996-10-29

406

Mutation analysis of androgen receptor gene: multiple uses for a single test.  

PubMed

Androgen receptor gene mutations are one of the leading causes of disorders of sex development (DSD) exhibited by sexual ambiguity or sex reversal. In this study, 2 families with patients whom diagnosed clinically as androgen insensitivity syndrome (AIS) were physically and genetically examined. This evaluation carried out by cytogenetic and molecular analysis including karyotype and sequencing of SRY and AR genes. In family 1, two brothers and their mother were hemizygous and heterozygous respectively for c.2522G>A variant, while one of their healthy brother was a completely normal hemizygote. Family 2 assessment demonstrated the c.639G>A (rs6152) mutation in two siblings who were reared as girls. The SRY gene was intact in all of the study's participants. Our findings in family 1 could be a further proof for the pathogenicity of the c.2522G>A variant. Given the importance of AR mutations in development of problems such as sex assignment in AIS patients, definitive diagnosis and phenotype-genotype correlation could be achieved by molecular genetic tests that in turn could have promising impacts in clinical management and also in prenatal diagnosis of prospect offspring. In this regard, phenotype-genotype correlation could be helpful and achieved by molecular genetic tests. This could influence the clinical management of the patients as well as prenatal diagnosis for the prospective offspring. PMID:25241384

Shojaei, Azadeh; Behjati, Farkhondeh; Ebrahimzadeh-Vesal, Reza; Razzaghy-Azar, Maryam; Derakhshandeh-Peykar, Pupak; Izadi, Pantea; Kajbafzadeh, Abdol-Mohammad; Dowlatih, Mohammad-Ali; Karami, Fatemeh; Tavakkoly-Bazzaz, Javad

2014-12-01

407

Monitoring bioaugmenation with single-well push-pull tests in sediment systems contaminated with trichloroethene.  

PubMed

Bioaugmentation to enhance the rate and extent of reductive dechlorination of chlorinated ethenes was investigated in intermediate ( approximately 1 m) scale physical aquifer models (PAMs) designed to simulate the groundwater flow field near an injection well. Push-pull tests were used to quantify the reductive dechlorination of injected trichloroethene (TCE) and trichlorofluoroethene (TCFE) in prepared sediment packs with and without an added dechlorinating culture containing Dehalococcoides spp. Distribution of the added culture throughout the sediment pack was confirmed by microscopic observation. Repeated additions of TCE (100-350 microM) were completely transformed to ethene in 14 days and a subsequent TCFE addition (114 microM) was completely transformed to fluoroethene (FE) in 24 days. Similar transformation rates, product distributions, and time courses for TCE and TCFE transformation were observed when these compounds were added together at similar initial concentrations. In the control PAM (nonbioaugmented), TCE and TCFE were transformed to only cis-DCE and cis-DCFE, respectively, and transformation rates were 6-12 times slower than those in the bioaugmented PAM. The use of TCFE for push-pull tests is shown to be an effective tool for detecting and quantifying the effects of bioaugmentation on TCE transformation. PMID:20030401

Lee, Jae-Hyuk; Dolan, Mark; Field, Jennifer; Istok, Jonathan

2010-02-01

408

Morphological and functional changes of dissociated single pancreatic acinar cells: testing the suitability of the single cell as a model for exocytosis and calcium signaling  

Microsoft Academic Search

Isolated single pancreatic acinar cells have long been used as a model for studying many kinds of signaling processes due to their structural and functional polarities, but without significant validation. In this study, we examined the morphological and functional changes of dissociated single pancreatic acinar cells.Acutely isolated single cells showed a collapsed membrane potential and a much reduced secretion of

Myoung Kyu Park; Misun Lee; Ole H Petersen

2004-01-01

409

Antifungal susceptibility testing of Candida spp. by relative growth measurement at single concentrations of antifungal agents.  

PubMed Central

The relative growth (percentage of growth relative to control growth) of 496 isolates representing six Candida species was assessed as a means of determining in vitro susceptibilities of the isolates in microdilution plate wells containing single concentrations of each of seven antifungal agents. The relative growth data were highly reproducible. With flucytosine and amorolfine they correlated well with MICs, but for an azole antifungal agent, terconazole, they did not correlate with MICs. Distributions of relative growth percentages for different Candida spp. showed significant differences in species susceptibility to individual agents. For example, C. albicans was less susceptible than the other species to amorolfine; C. parapsilosis isolates were particularly susceptible to terbinafine; and C. glabrata, C. guilliermondii, and C. krusei isolates were less susceptible than C. albicans to fluconazole and ketoconazole but equally susceptible as or more susceptible than C. albicans to itraconazole. Differential patterns of susceptibility to individual azole antifungal agents were noted for some individual strains as well as for Candida spp. PMID:1416856

Odds, F C

1992-01-01

410

Unraveling sexual associations in contact and noncontact child sex offenders using the single category - implicit association test.  

PubMed

Previous studies found associations between children and sex in child sex offenders (CSOs) using the Implicit Association Test (IAT). We used a modification of this task, the Single Category-Implicit Association Test (SC-IAT) to unravel child-sex associations in CSOs. Using the SC-IAT, we were able to test whether CSOs indeed hold stronger child-sex associations relative to adult-sex associations, compared to adult sex offenders and nonoffenders. Furthermore, we examined whether contact CSOs differed from noncontact CSOs in their child-sex associations. The hypothesis that CSOs would have stronger child-sex associations, relative to their adult-sex associations, than adult sex offenders and nonoffenders was confirmed. No difference between contact CSOs and noncontact CSOs was found. Although the Sex SC-IAT was able to distinguish CSOs from nonoffenders, the sensitivity and specificity of the test was poor (AUC of .65) and needs refinement. The results of this study support the existence of a child-sex association as a distinctive characteristic of CSOs. These findings are discussed in the context of theories on deviant cognitions in CSOs and risk for sexual offending. PMID:23125056

Hempel, I S; Buck, N M L; Goethals, K R; van Marle, H J C

2013-10-01

411

Synthetic Nanopores as a Test Case for Ion Channel Theories: The Anomalous Mole Fraction Effect without Single Filing  

PubMed Central

The predictions of a theory for the anomalous mole fraction effect (AMFE) are tested experimentally with synthetic nanopores in plastic. The negatively charged synthetic nanopores under consideration are highly cation selective and 50 Å in diameter at their smallest point. These pores exhibit an AMFE in mixtures of Ca2+ and monovalent cations. An AMFE occurs when the conductance through a pore is lower in a mixture of salts than in the pure salts at the same concentration. For ion channels, the textbook interpretation of the AMFE is that multiple ions move through the pore in coordinated, single-file motion. However, because the synthetic nanopores are so wide, their AMFE shows that single filing is not necessary for the AMFE. It is shown that the AMFE in the synthetic nanopores is explained by a theory of preferential ion selectivity. The unique properties of the synthetic nanopores allow us to experimentally confirm several predictions of this theory. These same properties make synthetic nanopores an interesting new platform to test theories of ion channel permeation and selectivity in general. PMID:18390596

Gillespie, Dirk; Boda, Dezs?; He, Yan; Apel, Pavel; Siwy, Zuzanna S.

2008-01-01

412

Single-Well-Gas-Sparging Tests for Assessing the Feasibility of In-situ Aerobic Treatment of CAH Mixtures  

NASA Astrophysics Data System (ADS)

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 standard monitoring wells. Transport characteristics of dissolved solutes [sulfur hexafluoride (SF6 or bromide (tracer), propane or methane (growth substrate), ethylene, propylene (nontoxic surrogates to probe for CAH transformation activity), and dissolved oxygen], were evaluated by push-pull transport tests. Mass balance showed about 90% of the injected bromide and about 80% of the injected SF6 were recovered, and the recoveries of other solutes were comparable with bromide and SF6. The transport tests demonstrated that bromide and SF6 could be used as conservative tracers for biological activity tests and that little loss of the dissolved gaseous substrates prior to biostimulation occurred. The dissolved gases were also conservatively transported indicating negligible trapped gas was present in the aquifer prior to sparging. A series of gas-sparging biostimulation tests were performed by sparging propane-(or methane)-oxygen-argon-SF6 gas mixture at specific depth intervals using a "straddle" packer. Temporal groundwater samples were obtained from the injection well under natural gradient "drift" conditions. Biostimulation was demonstrated with repeated gas sparging tests where the time to deplete methane and propane concentrations decreased compared to SF6. Gas sparging activity tests were performed using the same procedures as the gas-sparging biostimulation tests, except that ethylene and propylene were included in the sparging gas mixtures. Propane (or methane) utilization, DO consumption, and ethylene and propylene cometabolism were well demonstrated. The stimulated propane- and methane-utilizers cometabolized ethylene and propylene to produce ethylene oxide and propylene oxide as cometabolic by-products. The results confirmed the biostimulation of indigenous microorganisms with cometabolism ability. When acetylene was included in the sparge gas mixture, propane and methane utilization and ethylene and propylene transformation were effectively blocked, indicating monooxygenase enzymes were involved

Kim, Y.; Istok, J.; Semprini, L.

2002-12-01

413

Transient nucleation in glasses  

NASA Technical Reports Server (NTRS)

Nucleation rates in condensed systems are frequently not at their steady state values. Such time dependent (or transient) nucleation is most clearly observed in devitrification studies of metallic and silicate glasses. The origin of transient nucleation and its role in the formation and stability of desired phases and microstructures are discussed. Numerical models of nucleation in isothermal and nonisothermal situations, based on the coupled differential equations describing cluster evolution within the classical theory, are presented. The importance of transient nucleation in glass formation and crystallization is discussed.

Kelton, K. F.

1991-01-01

414

Multiple-Beam Detection of Fast Transient Radio Sources  

NASA Technical Reports Server (NTRS)

A method has been designed for using multiple independent stations to discriminate fast transient radio sources from local anomalies, such as antenna noise or radio frequency interference (RFI). This can improve the sensitivity of incoherent detection for geographically separated stations such as the very long baseline array (VLBA), the future square kilometer array (SKA), or any other coincident observations by multiple separated receivers. The transients are short, broadband pulses of radio energy, often just a few milliseconds long, emitted by a variety of exotic astronomical phenomena. They generally represent rare, high-energy events making them of great scientific value. For RFI-robust adaptive detection of transients, using multiple stations, a family of algorithms has been developed. The technique exploits the fact that the separated stations constitute statistically independent samples of the target. This can be used to adaptively ignore RFI events for superior sensitivity. If the antenna signals are independent and identically distributed (IID), then RFI events are simply outlier data points that can be removed through robust estimation such as a trimmed or Winsorized estimator. The alternative "trimmed" estimator is considered, which excises the strongest n signals from the list of short-beamed intensities. Because local RFI is independent at each antenna, this interference is unlikely to occur at many antennas on the same step. Trimming the strongest signals provides robustness to RFI that can theoretically outperform even the detection performance of the same number of antennas at a single site. This algorithm requires sorting the signals at each time step and dispersion measure, an operation that is computationally tractable for existing array sizes. An alternative uses the various stations to form an ensemble estimate of the conditional density function (CDF) evaluated at each time step. Both methods outperform standard detection strategies on a test sequence of VLBA data, and both are efficient enough for deployment in real-time, online transient detection applications.

Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.

2011-01-01

415

42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...  

Code of Federal Regulations, 2010 CFR

... Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1144 Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

2010-10-01

416

42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...  

Code of Federal Regulations, 2011 CFR

... Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1144 Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...

2011-10-01

417

42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...  

... 1 2014-10-01 2014-10-01 false Silica dust test for dust, fume, and mist respirators; single-use or reusable...ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray;...

2014-10-01

418

42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...  

Code of Federal Regulations, 2012 CFR

... 1 2012-10-01 2012-10-01 false Silica dust test for dust, fume, and mist respirators; single-use or reusable...ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray;...

2012-10-01

419

42 CFR 84.1144 - Silica dust test for dust, fume, and mist respirators; single-use or reusable filters; minimum...  

Code of Federal Regulations, 2013 CFR

... 1 2013-10-01 2013-10-01 false Silica dust test for dust, fume, and mist respirators; single-use or reusable...ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray;...

2013-10-01

420

Testing  

MedlinePLUS

... curesma.org > learn about sma > causes & diagnoses > testing Testing An SMA diagnosis must be confirmed through genetic ... and must be identified through further testing. Prenatal Testing Prenatal testing is used to determine if a ...

421

Test plan for single well injection/extraction characterization of DNAPL  

SciTech Connect

Soils and groundwater beneath an abandoned Process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLS, or dense non aqueous Phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small contained spill sites) is the only ``proven`` cleanup method. New cleanup approaches based on enhanced removal by surfactants and/or alcohols have been proposed and tested at the pilot scale. As described below, carefully designed experiments similar to the enhanced removal methods may provide important characterization information on DNAPLs.

Looney, B.B.; Jerome, K.M.; Burdick, S.; Rossabi, J.; Jarosch, T.R.; Eddy-Dilek, C.A.

1995-12-01

422

COBRA-WC pretest predictions and post-test analysis of the FOTA temperature distribution during FFTF natural-circulation transients  

SciTech Connect

The natural circulation tests of the Fast Flux Test Facility (FFTF) demonstrated a safe and stable transition from forced convection to natural convection and showed that natural convection may adequately remove decay heat from the reactor core. The COBRA-WC computer code was developed by the Pacific Northwest laboratory (PNL) to account for buoyancy-induced coolant flow redistribution and interassembly heat transfer, effects that become important in mitigating temperature gradients and reducing reactor core temperatures when coolant flow rate in the core is low. This report presents work sponsored by the US Department of Energy (DOE) with the objective of checking the validity of COBRA-WC during the first 220 seconds (sec) of the FFTF natural-circulation (plant-startup) tests using recorded data from two instrumented Fuel Open Test Assemblies (FOTAs). Comparison of COBRA-WC predictions of the FOTA data is a part of the final confirmation of the COBRA-WC methodology for core natural-convection analysis.

Khan, E.U.; George, T.L.; Rector, D.R.

1982-06-23

423

Family-based association tests for qualitative and quantitative traits using single-nucleotide polymorphism and microsatellite data.  

PubMed

Using the Genetic Analysis Workshop 12 simulated data, we contrasted results for association tests in nuclear families and extended pedigrees using single-nucleotide polymorphism (SNP) data, and we compared results for different trait definitions, for outbred and isolate populations, and for SNP and microsatellite data. SNPs in major genes 1 and 6 were analyzed using transmission disequilibrium testing (TDT) [Spielman et al., Am J Hum Genet 52:506-16, 1993], sibship disequilibrium testing (SDT) [Horvath and Laird, Am J Hum Genet 63:1886-97, 1998], family-based association testing (FBAT) [Horvath et al., Eur J Hum Genet 9:301-6, 2001], and a chi-square analysis of founders. TDT and SDT were applied in a sample of independent nuclear families, while FBAT was applied in extended pedigrees. SNPs and microsatellites were analyzed with dichotomous and quantitative trait definitions using FBAT in the isolate and outbred populations. The results of the TDT, SDT, and FBAT analyses are comparable using SNP data to identify the disease gene. However, these tests of association were not helpful in discriminating between functional and non-functional SNPs in disequilibrium. SNP data were able to identify association with affection status in a gene that influences the liability directly (MG6), but did not perform as well when assessing association with affection status in a gene that influences the outcome only through a quantitative trait (MG1). Association with MG1 was observed using the SNP data when the outcome was defined quantitatively. Microsatellite data were relatively unsuccessful in identifying association with the markers in the region of a major gene. The magnitude of the associations between SNPs and the dichotomous or quantitative trait definitions were similar in the outbred and isolated populations. PMID:11793700

Wilk, J B; Volcjak, J S; Myers, R H; Maher, N E; Knowlton, B A; Heard-Costa, N L; Demissie, S; Cupples, L A; DeStefano, A L

2001-01-01

424

A New Parameter to Assess Hydromechanical Effect in Single-hole Hydraulic Testing and Grouting  

SciTech Connect

Grouting or filling of the open voids in fractured rock is done by introducing a fluid, a grout, through boreholes under pressure. The grout may be either a Newtonian fluid or a Bingham fluid. The penetration of the grout and the resulting pressure profile may give rise to hydromechanical effects, which depends on factors such as the fracture aperture, pressure at the borehole and the rheological properties of the grout. In this paper, we postulate that a new parameter, {angstrom}, which is the integral of the fluid pressure change in the fracture plane, is an appropriate measure to describe the change in fracture aperture volume due to a change in effective stress. In many cases, analytic expressions are available to calculate pressure profiles for relevant input data and the {angstrom} parameter. The approach is verified against a fully coupled hydromechanical simulator for the case of a Newtonian fluid. Results of the verification exercise show that the new approach is reasonable and that the {angstrom}-parameter is a good measure for the fracture volume change: i.e., the larger the {angstrom}-parameter, the larger the fracture volume change, in an almost linear fashion. To demonstrate the application of the approach, short duration hydraulic tests and constant pressure grouting are studied. Concluded is that using analytic expressions for penetration lengths and pressure profiles to calculate the {angstrom} parameter provides a possibility to describe a complex situation and compare, discuss and weigh the impact of hydromechanical couplings for different alternatives. Further, the analyses identify an effect of high-pressure grouting, where uncontrolled grouting of larger fractures and insufficient (or less-than-expected) sealing of finer fractures is a potential result.

Rutqvist, Jonny; Fransson, A.; Tsang, C.-F.; Rutqvist, J.; Gustafson, G.

2007-09-01

425

Femtosecond Transient Imaging  

E-print Network

This thesis proposes a novel framework called transient imaging for image formation and scene understanding through impulse illumination and time images. Using time-of-flight cameras and multi-path analysis of global light ...

Kirmani, Ahmed (Ghulam Ahmed)

2010-01-01

426

Measurement of transient reflectance  

NASA Technical Reports Server (NTRS)

Real-time reflectometer, adjusted to a fraction of a second, monitors transient effects and allows sample to be exposed to environment continuously. Reflectance and reference signals share same optical path, minimizing extraneous effects.

Zwiener, J. M.

1976-01-01

427

Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area  

SciTech Connect

Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).

Pruess, K.; Doughty, C.

2010-01-15

428

Single-event Effect Report for EPC Series eGaN FETs: Proton Testing for SEE and TNID Effects  

NASA Technical Reports Server (NTRS)

Previous testing of the Enhanced Power Conversion (EPC) eGaN FETs showed sensitivity to destructive single-event effects (SEE) effects to heavy ions. The presence of tungsten plugs in the gate area raises concerns that the device may be vulnerable to SEE from protons. Irradiation of biased and unbiased devices with heavy ion has results in some damage suspected of being due to total non-ionizing dose (TNID). Proton irradiation is a better radiation type to study this effect. This study presents the results of testing device with protons for SEE and TNID. No SEE in the EPC2012 device, the most sensitive device to SEE, were seen with 53 MeV protons at several angles. The devices continued to function after 1.5 Mrad (Si) of proton dose with only a slight shift in parameters. These results suggest that gross TNID will not be a factor in using these devices nor suffer from SEE due to protons. However, the device should be tested at with 500 MeV protons to guarantee to immunity proton SEE.

Scheick, Leif

2014-01-01

429

Wavelets and power system transients: feature detection and classification  

NASA Astrophysics Data System (ADS)

This paper presents a methodology for the development of software for classifying power system disturbances by type from the transient waveform signature. The implementation of classification capability in future transient recorders will enable such features as selective storage of transient data (t