Black English Phonology: The Question of Reading Interference.

ERIC Educational Resources Information Center

Melmed, Paul Jay

An investigation was conducted to test the assumption that Black English (BE) dialect interferes with reading. Data from 45 lower standard English (SE) speakers were collected and analyzed to measure racial group differences on auditory discrimination, oral reading, BE phonology usage, and silent reading comprehension. Dialect differences analyzed…

Utility of an appropriate reporter assay: Heliotrine interferes with GAL4/upstream activation sequence-driven reporter gene systems.

PubMed

Luckert, Claudia; Hessel, Stefanie; Lampen, Alfonso; Braeuning, Albert

2015-10-15

Reporter gene assays are widely used for the assessment of transcription factor activation following xenobiotic exposure of cells. A critical issue with such assays is the possibility of interference of test compounds with the test system, for example, by direct inhibition of the reporter enzyme. Here we show that the pyrrolizidine alkaloid heliotrine interferes with reporter signals derived from GAL4-based nuclear receptor transactivation assays by a mechanism independent of luciferase enzyme inhibition. These data highlight the necessity to conduct proper control experiments in order to avoid perturbation of reporter assays by test chemicals. Copyright © 2015 Elsevier Inc. All rights reserved.

Experiments in a three-dimensional adaptive-wall wind tunnel

NASA Technical Reports Server (NTRS)

Schairer, E. T.

1983-01-01

Three dimensional adaptive-wall experiments were performed in the Ames Research Center (ARC) 25- by 13-cm indraft wind tunnel. A semispan wing model was mounted to one sidewall of a test section with solid sidewalls, and slotted top and bottom walls. The test section had separate top and bottom plenums which were divided into streamwise and cross-stream compartments. An iterative procedure was demonstrated for measuring wall interference and for adjusting the plenum compartment pressures to eliminate such interference. The experiments were conducted at a freestream Mach number of 0.60 and model angles of attack between 0 and 6 deg. Although in all the experiments wall interference was reduced after the plenum pressures were adjusted, interference could not be completely eliminated.

Viking telecommunication effects of GEOS satellite interference based on testing at the Madrid deep space station

NASA Technical Reports Server (NTRS)

Stuhr, F. V.; Kent, S. S.; Galvez, J. L.; Luaces, B. G.; Pasero, G. R.; Urech, J. M.

1976-01-01

In support of the ongoing NASA-European Space Agency (ESA) effort to understand and control possible interference between missions, testing was conducted at the Madrid Deep Space Station from July 1975 to February 1976 to characterize the effect on Viking 1975 telecommunication link performance of Geodetic Earth-Orbiting Satellite (GEOS) downlink signals. The prime use of the data was to develop a capability to predict GEOS interference effects for evaluation of Viking 1975 mission impacts and possible temporary GEOS shutdown. Also, the data would serve as a basis for assessment of the GEOS impact on missions other than Viking as well as for more general interference applications. Performances of the reference receiver, telemetry, and planetary ranging were measured in the presence of various types of GEOS-related interference, including an unmodulated GEOS carrier and simulation of the actual spectrum by an ESA-supplied GEOS suitcase model.

Test report: Electron-proton spectrometer qualification test unit, qualification test

NASA Technical Reports Server (NTRS)

Vincent, D. L.

1972-01-01

Qualification tests of the electron-proton spectrometer test unit are presented. The tests conducted were: (1) functional, (2) thermal/vacuum, (3) electromagnetic interference, (4) acoustic, (5) shock, (6) vibration, and (7) humidity. Results of each type of test are presented in the form of data sheets.

An experimental study of wall adaptation and interference assessment using Cauchy integral formula

NASA Technical Reports Server (NTRS)

Murthy, A. V.

1991-01-01

This paper summarizes the results of an experimental study of combined wall adaptation and residual interference assessment using the Cauchy integral formula. The experiments were conducted on a supercritical airfoil model in the Langley 0.3-m Transonic Cryogenic Tunnel solid flexible wall test section. The ratio of model chord to test section height was about 0.7. The method worked satisfactorily in reducing the blockage interference and demonstrated the primary requirement for correcting for the blockage effects at high model incidences to correctly determine high lift characteristics. The studies show that the method has potential for reducing the residual interference to considerably low levels. However, corrections to blockage and upwash velocities gradients may still be required for the final adapted wall shapes.

Interference of GSM mobile phones with communication between Cardiac Rhythm Management devices and programmers: A combined in vivo and in vitro study.

PubMed

Huang, Dong; Dong, Zhi-Feng; Chen, Yan; Wang, Fa-Bin; Wei, Zhi; Zhao, Wen-Bin; Li, Shuai; Liu, Ming-Ya; Zhu, Wei; Wei, Meng; Li, Jing-Bo

2015-07-01

To investigate interference, and how to avoid it, by high-frequency electromagnetic fields (EMFs) of Global System for Mobile Communications (GSM) mobile phone with communication between cardiac rhythm management devices (CRMs) and programmers, a combined in vivo and in vitro testing was conducted. During in vivo testing, GSM mobile phones interfered with CRM-programmer communication in 33 of 65 subjects tested (50.8%). Losing ventricle sensing was representative in this study. In terms of clinical symptoms, only 4 subjects (0.6%) felt dizzy during testing. CRM-programmer communication recovered upon termination of mobile phone communication. During in vitro testing, electromagnetic interference by high-frequency (700-950 MHz) EMFs reproducibly occurred in duplicate testing in 18 of 20 CRMs (90%). During each interference, the pacing pulse signal on the programmer would suddenly disappear while the synchronous signal was normal on the amplifier-oscilloscope. Simulation analysis showed that interference by radiofrequency emitting devices with CRM-programmer communication may be attributed to factors including materials, excitation source distance, and implant depth. Results suggested that patients implanted with CRMs should not be restricted from using GSM mobile phones; however, CRMs should be kept away from high-frequency EMFs of GSM mobile phone during programming. © 2015 Wiley Periodicals, Inc.

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

Tabulated pressure measurements on a large subsonic transport model airplane with high bypass ratio, powered, fan jet engines

NASA Technical Reports Server (NTRS)

Flechner, S. G.; Patterson, J. C., Jr.

1972-01-01

An experimental wind-tunnel investigation to determine the aerodynamic interference and the jet-wake interference associated with the wing, pylon, and high-bypass-ratio, powered, fan-jet model engines has been conducted on a typical high-wing logistics transport airplane configuration. Pressures were measured on the wing and pylons and on the surfaces of the engine fan cowl, turbine cowl, and plug. Combinations of wing, pylons, engines, and flow-through nacelles were tested, and the pressure coefficients are presented in tabular form. Tests were conducted at Mach numbers from 0.700 to 0.825 and angles of attack from -2 to 4 deg.

Comparison of airfoil results from an adaptive wall test section and a porous wall test section

NASA Technical Reports Server (NTRS)

Mineck, Raymond E.

1989-01-01

Two wind tunnel investigations were conducted to assess two different wall interference alleviation/correction techniques: adaptive test section walls and classical analytical corrections. The same airfoil model has been tested in the adaptive wall test section of the NASA-Langley 0.3 m Transonic Cryogenic Tunnel (TCT) and in the National Aeronautical Establishment (NAE) High Reynolds Number 2-D facility. The model has a 9 in. chord and a CAST 10-2/DOA 2 airfoil section. The 0.3 m TCT adaptive wall test section has four solid walls with flexible top and bottom walls. The NAE test section has porous top and bottom walls and solid side walls. The aerodynamic results corrected for top and bottom wall interference at Mach numbers from 0.3 to 0.8 at a Reynolds number of 10 by 1,000,000. Movement of the adaptive walls was used to alleviate the top and bottom wall interference in the test results from the NASA tunnel.

Simulated propeller slipstream effects on a supercritical wing

NASA Technical Reports Server (NTRS)

Welge, H. R.; Crowder, J. P.

1978-01-01

To quantify the installed performance of high speed (M = 0.8) turboprop propulsion systems, an experimental program designed to assess the magnitude of the aerodynamic interference of a propeller slipstream on a supercritical wing has been conducted. The test was conducted in the NASA Ames 14-foot wind tunnel. An ejector-nacelle propeller slipstream simulator was used to produce a slipstream with characteristics typical of advanced propellers presently being investigated. A supercritical wing-body configuration was used to evaluate the interference effects. A traversing total pressure rake was used to make flow field measurements behind the wing and to calibrate the slipstream simulator. The force results indicated that the interference drag amounted to an increase of ten counts or about 3% of the wing-body drag for a two engine configuration at the nominal propeller operating conditions. However, at the higher swirl angles (11 deg vs. 7 deg nominally) the interference drag was favorable by about the same magnitude.

Slotted-wall research with disk and parachute models in a low-speed wind tunnel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macha, J.M.; Buffington, R.J.; Henfling, J.L.

1990-01-01

An experimental investigation of slotted-wall blockage interference has been conducted using disk and parachute models in a low speed wind tunnel. Test section open area ratio, model geometric blockage ratio, and model location along the length of the test section were systematically varied. Resulting drag coefficients were compared to each other and to interference-free measurements obtained in a much larger wind tunnel where the geometric blockage ratio was less than 0.0025. 9 refs., 10 figs.

Testing can counteract proactive interference by integrating competing information.

PubMed

Wahlheim, Christopher N

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A-B, A-D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A-B, A-B), control pairs appeared in List 2 only (A-B, C-D), and changed pairs appeared with the same cue in both lists but with different responses (A-B, A-D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information.

Evaluation of Wall Interference Effects in a Two-Dimensional Transonic Wind Tunnel by Subsonic Linear Theory,

DTIC Science & Technology

1979-02-01

tests were conducted on two geometrica lly similar models of each of two aerofoil sections -—t he NA CA 00/ 2 and the BGK- 1 sections -and covered a...and slotted-wall tes t sections are corrected for wind tunnel wall interference efJ~cts by the application of classical linearized theory. For the...solid wall results , these corrections appear to produce data which are very close to being free of the effects of interference. In the case of

Heat transfer phase change paint tests of 0.0175-scale models (nos. 21-0 and 46-0) of the Rockwell International space shuttle orbiter in the AEDC tunnel B hypersonic wind tunnel (test OH25A)

NASA Technical Reports Server (NTRS)

Dye, W. H.

1975-01-01

Tests were conducted in a hypersonic wind tunnel using various truncated space shuttle orbiter configurations in an attempt to establish the optimum model size for other tests examining body shock-wing leading edge interference effects. The tests were conducted at Mach number 8 using the phase change paint technique. A test description, tabulated data, and tracings of isotherms made from photographs taken during the test are presented.

Experimental evaluation of blockage ratio and plenum evacuation system flow effects on pressure distribution for bodies of revolution in 0.1 scale model test section of NASA Lewis Research Center's proposed altitude wind tunnel

NASA Technical Reports Server (NTRS)

Burley, Richard R.; Harrington, Douglas E.

1987-01-01

An experimental investigation was conducted in the slotted test section of the 0.1-scale model of the proposed Altitude Wind Tunnel to evaluate wall interference effects at tunnel Mach numbers from 0.70 to 0.95 on bodies of revolution with blockage rates of 0.43, 3, 6, and 12 percent. The amount of flow that had to be removed from the plenum chamber (which surrounded the slotted test section) by the plenum evacuation system (PES) to eliminate wall interference effects was determined. The effectiveness of tunnel reentry flaps in removing flow from the plenum chamber was examined. The 0.43-percent blockage model was the only one free of wall interference effects with no PES flow. Surface pressures on the forward part of the other models were greater than interference-free results and were not influenced by PES flow. Interference-free results were achieved on the aft part of the 3- and 6-percent blockage models with the proper amount of PES flow. The required PES flow was substantially reduced by opening the reentry flaps.

Testing can counteract proactive interference by integrating competing information

PubMed Central

Wahlheim, Christopher N.

2015-01-01

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A–B, A–D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A–B, A–B), control pairs appeared in List 2 only (A–B, C–D), and changed pairs appeared with the same cue in both lists but with different responses (A–B, A–D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information. PMID:25120241

Hazard Monitoring in a Spectrum-Challenged Future: US Department of Transportation Adjacent Band Compatibility Assessment of Interference on High-Precision GNSS Receivers

NASA Astrophysics Data System (ADS)

Blume, F.; Berglund, H. T.

2016-12-01

In 2012 the Federal Communications Commission (FCC) reversed its decision to allow communications company LightSquared to use GPS-adjacent spectrum for a ground based network after testing demonstrated harmful interference to GPS receivers. Now rebranded as Ligado, they have submitted modified application to use a smaller portion of the L-band spectrum at much lower power. Many GPS community stakeholders, including the hazard monitoring and EEW communities remain concerned that Ligado's proposed use could still cause harmful interference, causing signal degradation, real-time positioning errors, and total failure of GNSS hardware in widespread use in hazard monitoring networks. The Department of Transportation (DoT) has conducted hardware tests to determine adjacent-band transmitter power limit criteria that would prevent harmful interference from Ligado's operations. We present preliminary results produced from the data collected by the three UNAVCO receiver types tested: Trimble NetRS, Trimble NetR9, and Septentrio PolaRx5. In the first round of testing, simulated GNSS signals were broadcast in an anechoic chamber (pictured below) while interfering signals are broadcast simultaneously with varying amplitude and frequency. The older GPS-only NetRS receiver showed smaller reductions in SNR at frequencies adjacent to GPS L1 as compared to the other receivers, suggesting narrower L1 filter bandwidth in the RF frontend. The NetR9 showed greater decreases in observed SNR in the 1615 to 1625 MHz range when compared to the other two receivers. This suggests that the NetR9's L1 filter bandwidth has been increased to accommodate GNSS signals. Linearity tests were conducted to better relate SNR measurements between receiver types. The PolaRx5 receiver showed less SNR variation between tracking channels than both Trimble receivers. Our results show the power levels at which adjacent-band interference begins degrading receiver performance and eventually disables tracking. As the demand for spectrum for mobile applications increases, operators of hazard networks may need to consider the impact of RF interference on data quality and continuity. UNAVCO's participation ensures that our high precision GNSS community interests are represented in the future spectrum allocation decisions.

SOAC - State-of-the-Art Car Engineering Tests at Department of Transportation High Speed Ground Test Center : Volume 5. Structural, Voltage, and Radio Frequency Interference Tests

DOT National Transportation Integrated Search

1975-01-01

The six-volume report presents the technical methodology, data samples, and results of tests conducted on the SOAC on the Rail Transit Test Track at the High Speed Ground Test Center in Pueblo, Colorado during the period April to July 1973. The Test ...

Automatic EMC test system

NASA Astrophysics Data System (ADS)

Kasai, R.; Abe, T.; Sano, T.

Automated electromagnetic compatibility (EMC) tests for spacecraft hardware are described. EMC tests are divided into three categories: compensating measurement and calibration errors, comparison of test results with specification, and fine-frequency searching using predictive interference analysis. The automated system features an RF receiver and transmitter, a control system, and antennas. Trials are run with conducted and radiated emissions and conducted and radiated susceptibility over a frequency range of 0.1-40 GHz with narrow, broad and random broad band noise. The system meets military specifications 1541, 461, and 462.

Development and psychometric testing of an instrument designed to measure chronic pain in dogs with osteoarthritis

PubMed Central

Boston, Raymond C.; Coyne, James C.; Farrar, John T.

2010-01-01

Objective To develop and psychometrically test an owner self-administered questionnaire designed to assess severity and impact of chronic pain in dogs with osteoarthritis. Sample Population 70 owners of dogs with osteoarthritis and 50 owners of clinically normal dogs. Procedures Standard methods for the stepwise development and testing of instruments designed to assess subjective states were used. Items were generated through focus groups and an expert panel. Items were tested for readability and ambiguity, and poorly performing items were removed. The reduced set of items was subjected to factor analysis, reliability testing, and validity testing. Results Severity of pain and interference with function were 2 factors identified and named on the basis of the items contained in them. Cronbach’s α was 0.93 and 0.89, respectively, suggesting that the items in each factor could be assessed as a group to compute factor scores (ie, severity score and interference score). The test-retest analysis revealed κ values of 0.75 for the severity score and 0.81 for the interference score. Scores correlated moderately well (r = 0.51 and 0.50, respectively) with the overall quality-of-life (QOL) question, such that as severity and interference scores increased, QOL decreased. Clinically normal dogs had significantly lower severity and interference scores than dogs with osteoarthritis. Conclusions and Clinical Relevance A psychometrically sound instrument was developed. Responsiveness testing must be conducted to determine whether the questionnaire will be useful in reliably obtaining quantifiable assessments from owners regarding the severity and impact of chronic pain and its treatment on dogs with osteoarthritis. PMID:17542696

BIOTIN INTERFERENCE WITH ROUTINE CLINICAL IMMUNOASSAYS: UNDERSTAND THE CAUSES AND MITIGATE THE RISKS.

PubMed

Samarasinghe, Shanika; Meah, Farah; Singh, Vinita; Basit, Arshi; Emanuele, Nicholas; Emanuele, Mary Ann; Mazhari, Alaleh; Holmes, Earle W

2017-08-01

The objectives of this report are to review the mechanisms of biotin interference with streptavidin/biotin-based immunoassays, identify automated immunoassay systems vulnerable to biotin interference, describe how to estimate and minimize the risk of biotin interference in vulnerable assays, and review the literature pertaining to biotin interference in endocrine function tests. The data in the manufacturer's "Instructions for Use" for each of the methods utilized by seven immunoassay system were evaluated. We also conducted a systematic search of PubMed/MEDLINE for articles containing terms associated with biotin interference. Available original reports and case series were reviewed. Abstracts from recent scientific meetings were also identified and reviewed. The recent, marked, increase in the use of over-the-counter, high-dose biotin supplements has been accompanied by a steady increase in the number of reports of analytical interference by exogenous biotin in the immunoassays used to evaluate endocrine function. Since immunoassay methods of similar design are also used for the diagnosis and management of anemia, malignancies, autoimmune and infectious diseases, cardiac damage, etc., biotin-related analytical interference is a problem that touches every area of internal medicine. It is important for healthcare personnel to become more aware of immunoassay methods that are vulnerable to biotin interference and to consider biotin supplements as potential sources of falsely increased or decreased test results, especially in cases where a lab result does not correlate with the clinical scenario. FDA = U.S. Food & Drug Administration FT3 = free tri-iodothyronine FT4 = free thyroxine IFUs = instructions for use LH = luteinizing hormone PTH = parathyroid hormone SA/B = streptavidin/biotin TFT = thyroid function test TSH = thyroid-stimulating hormone.

An experimental study of several wind tunnel wall configurations using two V/STOL model configurations. [low speed wind tunnels

NASA Technical Reports Server (NTRS)

Binion, T. W., Jr.

1975-01-01

Experiments were conducted in the low speed wind tunnel using two V/STOL models, a jet-flap and a jet-in-fuselage configuration, to search for a wind tunnel wall configuration to minimize wall interference on V/STOL models. Data were also obtained on the jet-flap model with a uniform slotted wall configuration to provide comparisons between theoretical and experimental wall interference. A test section configuration was found which provided some data in reasonable agreement with interference-free results over a wide range of momentum coefficients.

Sensitivity Study of the Wall Interference Correction System (WICS) for Rectangular Tunnels

NASA Technical Reports Server (NTRS)

Walker, Eric L.; Everhart, Joel L.; Iyer, Venkit

2001-01-01

An off-line version of the Wall Interference Correction System (WICS) has been implemented for the NASA Langley National Transonic Facility. The correction capability is currently restricted to corrections for solid wall interference in the model pitch plane for Mach numbers less than 0.45 due to a limitation in tunnel calibration data. A study to assess output sensitivity to measurement uncertainty was conducted to determine standard operational procedures and guidelines to ensure data quality during the testing process. Changes to the current facility setup and design recommendations for installing the WICS code into a new facility are reported.

A study of interferences in ozone UV and chemiluminescence monitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hudgens, E.E.; Kleindienst, T.E.; McElroy, F.F.

A study was conducted to examine interferences and other measurement anomalies in chemiluminescence and ultraviolet ozone monitors. Previous results had show that there was a positive deviation in the chemiluminescence monitors and no direct interference with ultraviolet monitors due to the presence of water at non-condensing concentrations. The present study continues this effort, examining both potential positive and negative effects of moisture and other interferences on these monitors. Aromatic compounds and their oxidation products could potentially show a positive interference with ultraviolet monitors, and test measurements were made with aromatics such as toluene, benzaldehyde, and nitrotoluene to determine their possiblemore » retention in the ozone scrubber and their absorption in the cell as a function of the humidity. A detailed examination of the scrubbers used in ultraviolet ozone monitors has also been undertaken. Ozone scrubbers that have shown anomalous behavior in the field have been studied in various reduced-efficacy modes under controlled laboratory conditions. Longer term tests of unused scrubbers for possible ozone breakthrough under exposure to various simulated field conditions were initiated.« less

The Effect of Nacelle-Propeller Diameter Ratio on Body Interference and on Propeller and Cooling Characteristics

NASA Technical Reports Server (NTRS)

Mchugh, James G; Derring, Eldridge H

1939-01-01

Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.

IFT&E Industry Report Wind Turbine-Radar Interference Test Summary.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karlson, Benjamin; LeBlanc, Bruce Philip.; Minster, David G

2014-10-01

Wind turbines have grown in size and capacity with today's average turbine having a power capacity of around 1.9 MW, reaching to heights of over 495 feet from ground to blade tip, and operating with speeds at the tip of the blade up to 200 knots. When these machines are installed within the line-of-sight of a radar system, they can cause significant clutter and interference, detrimentally impacting the primary surveillance radar (PSR) performance. The Massachusetts Institute of Technology's Lincoln Laboratory (MIT LL) and Sandia National Laboratories (SNL) were co-funded to conduct field tests and evaluations over two years in ordermore » to: I. Characterize the impact of wind turbines on existing Program-of-Record (POR) air surveillance radars; II. Assess near-term technologies proposed by industry that have the potential to mitigate the interference from wind turbines on radar systems; and III. Collect data and increase technical understanding of interference issues to advance development of long-term mitigation strategies. MIT LL and SNL managed the tests and evaluated resulting data from three flight campaigns to test eight mitigation technologies on terminal (short) and long-range (60 nmi and 250 nmi) radar systems. Combined across the three flight campaigns, more than 460 of hours of flight time were logged. This paper summarizes the Interagency Field Test & Evaluation (IFT&E) program and publicly- available results from the tests. It will also discuss the current wind turbine-radar interference evaluation process within the government and a proposed process to deploy mitigation technologies.« less

Stress intensity factors for part-elliptical cracks emanating from dimpled rivet holes

NASA Astrophysics Data System (ADS)

Wang, Ailun; She, Chongmin; Lin, Gang; Zhou, You; Guo, Wanlin

2014-11-01

Detailed investigations on the stress intensity factors (SIFs) for corner cracks emanated from interference fitted dimpled rivet holes are conducted using three-dimensional finite element method. The influences of the crack length a, elliptical shape factor t, far-end stress S and interference magnitude δ on the stress intensity factors are systematically studied. The SIFs for corner cracks emanated from open holes are also investigated for comparisons. An empirical formula of the normalized SIF is proposed by use of the least square method for convenience of the engineering application, which is a function of the crack length a, elliptical shape factor t, far-end stress S, interference magnitude δ and the normalized elliptical centrifugal angle φn. Based on the empirical formula, a crack growth simulation for a rivet filled hole is conducted, which shows a good agreement with the test data.

Space shuttle launch vehicle (13 P-OTS) strut support interference effects study in the Rockwell International 7- by 7-foot trisonic wind tunnel (IA68)

NASA Technical Reports Server (NTRS)

Rogge, R. L.

1974-01-01

Strut support interference investigations were conducted on an 0.004-(-) scale representation of the space shuttle launch vehicle in order to determine transonic and supersonic model support interference effects for use in a future exhaust plume effects study. Strut configurations were also tested. Orbiter, external tank, and solid rocket booster pressures were recorded at Mach numbers 0.9, 1.2, 1.5, and 2.0. Angle of attack and angle of sideslip were varied between plus or minus 4 degrees in 2 degree increments. Parametric variations consisted only of the strut configurations.

The effect of breath freshener strips on two types of breath alcohol testing instruments.

PubMed

Moore, Ronald L; Guillen, Jennifer

2004-07-01

The potential for breath freshener strips to interfere with the accuracy of a breath alcohol test was studied. Twelve varieties of breath freshener strips from five manufacturers were examined. Breath tests were conducted using the infrared based BAC DataMaster or the fuel cell based Alco-Sensor IV-XL, 30 and 150 seconds after placing a breath strip on the tongue. No effect was observed using the Alco-Sensor system. Some of the strips gave a small reading at 30 seconds (less than or equal to 0.010 g/210 L apparent alcohol) using the DataMaster. Readings on the DataMaster returned to zero by the 150 second test. A proper pre-test observation and deprivation period should prevent any interference from breath freshener strips on breath alcohol testing.

Primary Salvage Survey of the Interference of Radiowaves Emitted by Smartphones on Medical Equipment.

PubMed

Takao, Hiroyuki; Yeh, Yu Chih; Arita, Hiroyuki; Obatake, Takumi; Sakano, Teppei; Kurihara, Minoru; Matsuki, Akira; Ishibashi, Toshihiro; Murayama, Yuichi

2016-10-01

Use of mobile phones has become a standard reality of everyday living for many people worldwide, including medical professionals, as data sharing has drastically helped to improve quality of care. This increase in the use of mobile phones within hospitals and medical facilities has raised concern regarding the influence of radio waves on medical equipment. Although comprehensive studies have examined the effects of electromagnetic interference from 2G wireless communication and personal digital cellular systems on medical equipment, similar studies on more recent wireless technologies such as Long Term Evolution, wideband code division multiple access, and high-speed uplink access have yet to be published. Numerous tests targeting current wireless technologies were conducted between December 2012 and March 2013 in an anechoic chamber, shielded from external radio signals, with a dipole antenna to assess the effects of smartphone interference on several types of medical equipment. The interference produced by electromagnetic waves across five frequency bands from four telecommunication standards was assessed on 49 components from 22 pieces of medical equipment. Of the 22 pieces of medical equipment tested, 13 experienced interference at maximum transmission power. In contrast, at minimum transmission power, the maximum interference distance varied from 2 to 5 cm for different wireless devices. Four machines were affected at the minimum transmission power, and the maximum interference distance at the maximum transmission power was 38 cm. Results show that the interference from smartphones on medical equipment is very controllable.

Semantic interference in picture naming during dual-task performance does not vary with reading ability.

PubMed

Piai, Vitória; Roelofs, Ardi; Roete, Ingeborg

2015-01-01

Previous dual-task studies examining the locus of semantic interference of distractor words in picture naming have obtained diverging results. In these studies, participants manually responded to tones and named pictures while ignoring distractor words (picture-word interference, PWI) with varying stimulus onset asynchrony (SOA) between tone and PWI stimulus. Whereas some studies observed no semantic interference at short SOAs, other studies observed effects of similar magnitude at short and long SOAs. The absence of semantic interference in some studies may perhaps be due to better reading skill of participants in these than in the other studies. According to such a reading-ability account, participants' reading skill should be predictive of the magnitude of their interference effect at short SOAs. To test this account, we conducted a dual-task study with tone discrimination and PWI tasks and measured participants' reading ability. The semantic interference effect was of similar magnitude at both short and long SOAs. Participants' reading ability was predictive of their naming speed but not of their semantic interference effect, contrary to the reading ability account. We conclude that the magnitude of semantic interference in picture naming during dual-task performance does not depend on reading skill.

AMPA experimental communications systems

NASA Technical Reports Server (NTRS)

Beckerman, D.; Fass, S.; Keon, T.; Sielman, P.

1982-01-01

The program was conducted to demonstrate the satellite communication advantages of Adaptive Phased Array Technology. A laboratory based experiment was designed and implemented to demonstrate a low earth orbit satellite communications system. Using a 32 element, L-band phased array augmented with 4 sets of weights (2 for reception and 2 for transmission) a high speed digital processing system and operating against multiple user terminals and interferers, the AMPA system demonstrated: communications with austere user terminals, frequency reuse, communications in the face of interference, and geolocation. The program and experiment objectives are described, the system hardware and software/firmware are defined, and the test performed and the resultant test data are presented.

Interference of mobile phones and digitally enhanced cordless telecommunications mobile phones in renal scintigraphy.

PubMed

Stegmayr, Armin; Fessl, Benjamin; Hörtnagl, Richard; Marcadella, Michael; Perkhofer, Susanne

2013-08-01

The aim of the study was to assess the potential negative impact of cellular phones and digitally enhanced cordless telecommunication (DECT) devices on the quality of static and dynamic scintigraphy to avoid repeated testing in infant and teenage patients to protect them from unnecessary radiation exposure. The assessment was conducted by performing phantom measurements under real conditions. A functional renal-phantom acting as a pair of kidneys in dynamic scans was created. Data were collected using the setup of cellular phones and DECT phones placed in different positions in relation to a camera head to test the potential interference of cellular phones and DECT phones with the cameras. Cellular phones reproducibly interfered with the oldest type of gamma camera, which, because of its single-head specification, is the device most often used for renal examinations. Curves indicating the renal function were considerably disrupted; cellular phones as well as DECT phones showed a disturbance concerning static acquisition. Variable electromagnetic tolerance in different types of γ-cameras could be identified. Moreover, a straightforward, low-cost method of testing the susceptibility of equipment to interference caused by cellular phones and DECT phones was generated. Even though some departments use newer models of γ-cameras, which are less susceptible to electromagnetic interference, we recommend testing examination rooms to avoid any interference caused by cellular phones. The potential electromagnetic interference should be taken into account when the purchase of new sensitive medical equipment is being considered, not least because the technology of mobile communication is developing fast, which also means that different standards of wave bands will be issued in the future.

A methodology to enhance electromagnetic compatibility in joint military operations

NASA Astrophysics Data System (ADS)

Buckellew, William R.

The development and validation of an improved methodology to identify, characterize, and prioritize potential joint EMI (electromagnetic interference) interactions and identify and develop solutions to reduce the effects of the interference are discussed. The methodology identifies potential EMI problems using results from field operations, historical data bases, and analytical modeling. Operational expertise, engineering analysis, and testing are used to characterize and prioritize the potential EMI problems. Results can be used to resolve potential EMI during the development and acquisition of new systems and to develop engineering fixes and operational workarounds for systems already employed. The analytic modeling portion of the methodology is a predictive process that uses progressive refinement of the analysis and the operational electronic environment to eliminate noninterfering equipment pairs, defer further analysis on pairs lacking operational significance, and resolve the remaining EMI problems. Tests are conducted on equipment pairs to ensure that the analytical models provide a realistic description of the predicted interference.

Effects of auditory radio interference on a fine, continuous, open motor skill.

PubMed

Lazar, J M; Koceja, D M; Morris, H H

1995-06-01

The effects of human speech on a fine, continuous, and open motor skill were examined. A tape of auditory human radio traffic was injected into a tank gunnery simulator during each training session for 4 wk. of training for 3 hr. a week. The dependent variables were identification time, fire time, kill time, systems errors, and acquisition errors. These were measured by the Unit Conduct Of Fire Trainer (UCOFT). The interference was interjected into the UCOFT Tank Table VIII gunnery test. A Solomon four-group design was used. A 2 x 2 analysis of variance was used to assess whether interference gunnery training resulted in improvements in interference posttest scores. During the first three weeks of training, the interference group committed 106% more systems errors and 75% more acquisition errors than the standard group. The interference training condition was associated with a significant improvement from pre- to posttest of 44% in over-all UCOFT scores; however, when examined on the posttest the standard training did not improve performance significantly over the same period. It was concluded that auditory radio interference degrades performance of this fine, continuous, open motor skill, and interference training appears to abate the effects of this degradation.

A call for safer utilization of radio frequency identification in the e-health era.

PubMed

Liu, Chung-Feng; Hwang, Hsin-Ginn; Kuo, Kuang-Ming; Hung, Won-Fu

2011-10-01

The main purpose of this study was to investigate the perceptions of the electromagnetic interference (EMI) caused by radio frequency identification (RFID) with medical devices among hospitals as well as to call the attention of medical institutions to the development of RFID applications. A survey sponsored by the Department of Health of Taiwan was conducted and the target subjects were every hospital in Taiwan (486 in total). The survey topics included testing of RFID interference with medical devices and perceptions of safety issues of RFID. The main targets of the survey were the Chief Information Officers (CIOs) or the main person responsible for RFID systems in each hospital. Of the original 486 questionnaires mailed, 273 were returned. A return rate of 56.17% was obtained. The survey results revealed that only six hospitals had carried out tests on interference by RFID with medical devices, and the results of these tests indicated that RFID does not interfere with medical devices. A majority of hospitals understood that RFID may interfere with medical devices but did not think that this would seriously harm patients. The application of RFID in the healthcare industry is certainly promising; however, EMI issues must be appropriately handled. This study asserts that most hospitals do not understand or pay insufficient attention to the issue of RFID interference with patient safety or medical devices. In addition, most hospitals believe that the problem of RFID should be resolved by RFID vendors. Therefore, this study argues that medical institutions should develop more understanding of RFID issues and that more attention should be given to the potential problems of RFID interference when developing RFID applications.

Parameter Sensitivity Study of the Wall Interference Correction System (WICS)

NASA Technical Reports Server (NTRS)

Walker, Eric L.; Everhart, Joel L.; Iyer, Venkit

2001-01-01

An off-line version of the Wall Interference Correction System (WICS) has been implemented for the "NASA Langley National Transonic Facility. The correction capability is currently restricted to corrections for solid wall interference in the model pitch plane for Mach numbers, less than 0.45 due to a limitation in tunnel calibration data. A study to assess output sensitivity to the aerodynamic parameters of Reynolds number and Mach number was conducted on this code to further ensure quality during the correction process. In addition, this paper includes all investigation into possible correction due to a semispan test technique using a non metric standoff and all improvement to the standard data rejection algorithm.

43 CFR 423.22 - Interference with agency functions and disorderly conduct.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Interference with agency functions and..., AND WATERBODIES Rules of Conduct § 423.22 Interference with agency functions and disorderly conduct... behavior; (2) Language, utterance, gesture, display, or act that is obscene, physically threatening or...

Space shuttle: Determination of the aerodynamic interference between the space shuttle orbiter, external tank, and solid rocket booster on a 0.004 scale ascent configuration

NASA Technical Reports Server (NTRS)

Ramsey, P. E.; Buchholz, R.; Allen, E. C. JR.; Dehart, J.

1973-01-01

Wind tunnel tests were conducted to determine the aerodynamic interference between the space shuttle orbiter, external tank, and solid rocket booster on a 0.004 scale ascent configuration. Six component aerodynamic force and moment data were recorded over an angle of attack range from minus 10 to plus 10 degrees at zero degree sideslip. A sideslip range of minus 10 to plus 10 degrees at zero degree angle of attack was also tested. The Mach number range was varied from 0.6 to 4.96 with Reynolds number varying between 4.9 and 6.8 times one million per foot.

Crew Quarters (CQ) and Electromagnetic Interference (EMI) Measurement Facility Combined Impedance Study

NASA Technical Reports Server (NTRS)

Scully, Robert C.

2011-01-01

This report documents an investigation into observed failures associated with conducted susceptibility testing of Crew Quarters (CQ) hardware in the Johnson Space Center (JSC) Electromagnetic Interference (EMI) Measurement Facility, and the work accomplished to identify the source of the observed behavior. Investigation led to the conclusion that the hardware power input impedance was interacting with the facility power impedance leading to instability at the observed frequencies of susceptibility. Testing performed in other facilities did not show this same behavior, pointing back to the EMI Measurement Facility power as the potential root cause. A LISN emulating the Station power bus impedance was inserted into the power circuit, and the susceptibility was eliminated from the measurements.

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

NASA Technical Reports Server (NTRS)

Sorge, Richard N.

2013-01-01

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.

Effects of cruise engine location and power on interference

NASA Technical Reports Server (NTRS)

Bradley, D.

1972-01-01

Data are presented, in plotted form, of tests for determining the interference effects of space shuttle booster cruise engine location for power-on and power-off conditions. The tests were conducted in a 7 x 10 foot transonic wind tunnel; the model was a 0.015-scale space shuttle booster specially equipped for propulsion effects testing. Data were obtained over a Mach number range of 0.4 to 1.13 at angles of attack from -4 deg to 20 deg at zero degrees sideslip and at angles of sideslip from -6 deg to +6 deg at constant angles of attack of 0 deg, 6 deg, 15 deg, and in some cases 10 deg. Additional parameters investigated were: elevon deflection, canard deflection, aileron deflection, rudder deflection, canard position, and mass flow rate.

KSC-05PD-1073

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Payload Hazardous Servicing Facility, an electromagnetic interference verification test is being conducted on the solar arrays for the Mars Reconnaissance Orbiter (MRO) and an antenna simulator (yellow horizontal rod). If no interference is found during the test, the Shallow Radar Antenna (SHARAD) will be installed on the spacecraft. The spacecraft is undergoing multiple mechanical assembly operations and electrical tests to verify its readiness for launch. The MRO was built by Lockheed Martin for NASAs Jet Propulsion Laboratory in California. It is the next major step in Mars exploration and scheduled for launch from Launch Complex 41 at Cape Canaveral Air Force Station in a window opening Aug. 10. The MRO is an important next step in fulfilling NASAs vision of space exploration and ultimately sending human explorers to Mars and beyond.

Frequency Management for Electromagnetic Continuous Wave Conductivity Meters

PubMed Central

Mazurek, Przemyslaw; Putynkowski, Grzegorz

2016-01-01

Ground conductivity meters use electromagnetic fields for the mapping of geological variations, like the determination of water amount, depending on ground layers, which is important for the state analysis of embankments. The VLF band is contaminated by numerous natural and artificial electromagnetic interference signals. Prior to the determination of ground conductivity, the meter’s working frequency is not possible, due to the variable frequency of the interferences. Frequency management based on the analysis of the selected band using track-before-detect (TBD) algorithms, which allows dynamical frequency changes of the conductivity of the meter transmitting part, is proposed in the paper. Naive maximum value search, spatio-temporal TBD (ST-TBD), Viterbi TBD and a new algorithm that uses combined ST-TBD and Viterbi TBD are compared. Monte Carlo tests are provided for the numerical analysis of the properties for a single interference signal in the considered band, and a new approach based on combined ST-TBD and Viterbi algorithms shows the best performance. The considered algorithms process spectrogram data for the selected band, so DFT (Discrete Fourier Transform) could be applied for the computation of the spectrogram. Real–time properties, related to the latency, are discussed also, and it is shown that TBD algorithms are feasible for real applications. PMID:27070608

Frequency Management for Electromagnetic Continuous Wave Conductivity Meters.

PubMed

Mazurek, Przemyslaw; Putynkowski, Grzegorz

2016-04-07

Ground conductivity meters use electromagnetic fields for the mapping of geological variations, like the determination of water amount, depending on ground layers, which is important for the state analysis of embankments. The VLF band is contaminated by numerous natural and artificial electromagnetic interference signals. Prior to the determination of ground conductivity, the meter's working frequency is not possible, due to the variable frequency of the interferences. Frequency management based on the analysis of the selected band using track-before-detect (TBD) algorithms, which allows dynamical frequency changes of the conductivity of the meter transmitting part, is proposed in the paper. Naive maximum value search, spatio-temporal TBD (ST-TBD), Viterbi TBD and a new algorithm that uses combined ST-TBD and Viterbi TBD are compared. Monte Carlo tests are provided for the numerical analysis of the properties for a single interference signal in the considered band, and a new approach based on combined ST-TBD and Viterbi algorithms shows the best performance. The considered algorithms process spectrogram data for the selected band, so DFT (Discrete Fourier Transform) could be applied for the computation of the spectrogram. Real-time properties, related to the latency, are discussed also, and it is shown that TBD algorithms are feasible for real applications.

78 FR 26849 - Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

...--Acetone Test 14--Emergency Override Test 15--Radiofrequency Interference/Electromagnetic Interference Test... requirements; temperature extreme testing; radio frequency interference (RFI) or electromagnetic interference...

Community Members' Interference and Conduct of University Distance Learning Examinations in South Eastern Nigeria

ERIC Educational Resources Information Center

Unamma, Anthony Odera

2013-01-01

This research work was aimed at determining the degree of community members' interference in the conduct of university distance learning examination in South Eastern Nigeria. It was also aimed at finding out the factors responsible for the community members' interference, the ways by which interference is effected, the consequences and the…

Characteristics of electromagnetic interference generated during discharge of Mylar samples. [spacecraft-environment interaction simulation

NASA Technical Reports Server (NTRS)

Leung, P. L.

1984-01-01

This paper discusses the measurements of the electromagnetic interference (EMI) generated during discharges of Mylar samples. The two components of EMI, the conducted emission and the radiated emission, are characterized by the replacement current and the radiated RF spectrum respectively. The measured radiated RF spectra reveal important information on the source of the electromagnetic radiation. The possible sources are the replacement current pulse and the discharged generated plasma. The scaling of the amplitudes of the EMI, as a function of the area of the test sample, is also discussed.

Wind tunnel and analytical investigation of over-the-wing propulsion/air frame interferences for a short-haul aircraft at Mach numbers from 0.6 to 0.78. [conducted in the Lewis 8 by 6 foot tunnel

NASA Technical Reports Server (NTRS)

Wells, O. D.; Lopez, M. L.; Welge, H. R.; Henne, P. A.; Sewell, A. E.

1977-01-01

Results of analytical calculations and wind tunnel tests at cruise speeds of a representative four engine short haul aircraft employing upper surface blowing (USB) with a supercritical wing are discussed. Wind tunnel tests covered a range of Mach number M from 0.6 to 0.78. Tests explored the use of three USB nozzle configurations. Results are shown for the isolated wing body and for each of the three nozzle types installed. Experimental results indicate that a low angle nacelle and streamline contoured nacelle yielded the same interference drag at the design Mach number. A high angle powered lift nacelle had higher interference drag primarily because of nacelle boattail low pressures and flow separation. Results of varying the spacing between the nacelles and the use of trailing edge flap deflections, wing upper surface contouring, and a convergent-divergent nozzle to reduce potential adverse jet effects were also discussed. Analytical comparisons with experimental data, made for selected cases, indicate favorable agreement.

Strut and wall interference on jet-induced ground effects of a STOVL aircraft in hover

NASA Technical Reports Server (NTRS)

Kristy, Michael H.

1995-01-01

A small scale ground effect test rig was used to study the ground plane flow field generated by a STOVL aircraft in hover. The objective of the research was to support NASA-Ames Research Center planning for the Large Scale Powered Model (LSPM) test for the ARPA-sponsored ASTOVL program. Specifically, small scale oil flow visualization studies were conducted to make a relative assessment of the aerodynamic interference of a proposed strut configuration and a wall configuration on the ground plane stagnation line. A simplified flat plate model representative of a generic jet-powered STOVL aircraft was used to simulate the LSPM. Cold air jets were used to simulate both the lift fan and the twin rear engines. Nozzle Pressure Ratios were used that closely represented those used on the LSPM tests. The flow visualization data clearly identified a shift in the stagnation line location for both the strut and the wall configuration. Considering the experimental uncertainty, it was concluded that either the strut configuration o r the wall configuration caused only a minor aerodynamic interference.

Highlights of experience with a flexible walled test section in the NASA Langley 0.3-meter transonic cryogenic tunnel

NASA Technical Reports Server (NTRS)

Wolf, Stephen W. D.; Ray, Edward J.

1988-01-01

The unique combination of adaptive wall technology with a contonuous flow cryogenic wind tunnel is described. This powerful combination allows wind tunnel users to carry out 2-D tests at flight Reynolds numbers with wall interference essentially eliminated. Validation testing was conducted to support this claim using well tested symmetrical and cambered airfoils at transonic speeds and high Reynolds numbers. The test section hardware has four solid walls, with the floor and ceiling flexible. The method of adapting/shaping the floor and ceiling to eliminate top and bottom wall interference at its source is outlined. Data comparisons for different size models tested and others in several sophisticated 2-D wind tunnels are made. In addition, the effects of Reynolds number, testing at high lift with associated large flexible wall movements, the uniqueness of the adapted wall shapes, and the effects of sidewall boundary layer control are examined. The 0.3-m TCT is now the most advanced 2-D research facility anywhere.

A wall interference assessment/correction system

NASA Technical Reports Server (NTRS)

Lo, Ching F.; Overby, Glenn; Qian, Cathy X.; Sickles, W. L.; Ulbrich, N.

1992-01-01

A Wall Signature method originally developed by Hackett has been selected to be adapted for the Ames 12-ft Wind Tunnel WIAC system in the project. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating blockage wall interference. The lifting interference will be treated separately by representing in a horseshoe vortex system for the model's lifting effects. The development and implementation of a working prototype will be completed, delivered and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method--Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected data with those of the free-air simulation.

Inverse modeling of hydraulic tests in fractured crystalline rock based on a transition probability geostatistical approach

NASA Astrophysics Data System (ADS)

Blessent, Daniela; Therrien, René; Lemieux, Jean-Michel

2011-12-01

This paper presents numerical simulations of a series of hydraulic interference tests conducted in crystalline bedrock at Olkiluoto (Finland), a potential site for the disposal of the Finnish high-level nuclear waste. The tests are in a block of crystalline bedrock of about 0.03 km3 that contains low-transmissivity fractures. Fracture density, orientation, and fracture transmissivity are estimated from Posiva Flow Log (PFL) measurements in boreholes drilled in the rock block. On the basis of those data, a geostatistical approach relying on a transitional probability and Markov chain models is used to define a conceptual model based on stochastic fractured rock facies. Four facies are defined, from sparsely fractured bedrock to highly fractured bedrock. Using this conceptual model, three-dimensional groundwater flow is then simulated to reproduce interference pumping tests in either open or packed-off boreholes. Hydraulic conductivities of the fracture facies are estimated through automatic calibration using either hydraulic heads or both hydraulic heads and PFL flow rates as targets for calibration. The latter option produces a narrower confidence interval for the calibrated hydraulic conductivities, therefore reducing the associated uncertainty and demonstrating the usefulness of the measured PFL flow rates. Furthermore, the stochastic facies conceptual model is a suitable alternative to discrete fracture network models to simulate fluid flow in fractured geological media.

Factors influencing new graduate nurse burnout development, job satisfaction and patient care quality: a time-lagged study.

PubMed

Boamah, Sheila A; Read, Emily A; Spence Laschinger, Heather K

2017-05-01

To test a hypothesized model linking new graduate nurses' perceptions of their manager's authentic leadership behaviours to structural empowerment, short-staffing and work-life interference and subsequent burnout, job satisfaction and patient care quality. Authentic leadership and structural empowerment have been shown to reduce early career burnout among nurses. Short-staffing and work-life interference are also linked to burnout and may help explain the impact of positive, empowering leadership on burnout, which in turn influences job satisfaction and patient care quality. A time-lagged study of Canadian new graduate nurses was conducted. At Time 1, surveys were sent to 3,743 nurses (November 2012-March 2013) and 1,020 were returned (27·3% response rate). At Time 2 (May-July 2014), 406 nurses who responded at Time 1 completed surveys (39·8% response rate). Descriptive analysis was conducted in SPSS. Structural equation modelling in Mplus was used to test the hypothesized model. The hypothesized model was supported. Authentic leadership had a significant positive effect on structural empowerment, which in turn decreased both short-staffing and work-life interference. Short-staffing and work-life imbalance subsequently resulted in nurse burnout, lower job satisfaction and lower patient care quality 1 year later. The findings suggest that short-staffing and work-life interference are important factors influencing new graduate nurse burnout. Developing nurse managers' authentic leadership behaviours and working with them to create and sustain empowering work environments may help reduce burnout, increase nurse job satisfaction and improve patient care quality. © 2016 John Wiley & Sons Ltd.

Deceiving proteins! A case of lymphoma and high creatinine.

PubMed

Metraiah, El Hakem Abdelkarim; Regan, Helen; Louw, Johanna; Kidder, Dana

2017-01-23

Estimation of kidney function by measuring serum creatinine is one the commonest laboratory tests conducted in clinical practice. Enzymatic methods are often used to measure serum creatinine. Clinicians should be aware of the limitations of these methods, such as test interference with paraproteins.We present a case of falsely elevated serum creatinine in a patient referred for renal biopsy. The combination of fluctuating creatinine and normal blood urea level was unusual. Serum protein electrophoresis revealed the presence of an IgM paraprotein. Further investigations confirmed an underlying diagnosis of lymphoplasmacytoid lymphoma. This case highlights how IgM paraprotein can interfere with creatinine estimation by enzymatic assay and the utility of alternative methods of estimating serum creatinine. 2017 BMJ Publishing Group Ltd.

Interference of avian guano in analyses of fuel-contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, D.E.; Johnson, T.E.; Kreamer, D.K.

1996-01-01

Site characterization on Johnston Island, Johnston Atoll, Pacific Ocean, has yielded preliminary data that seabird guano can be an interference in three common petroleum hydrocarbon quantification methods. Volatiles from seabird guano were measured on a hydrocarbon-specific handheld vapor meter (catalytic detector) in concentrations as high as 256 ppm by volume total hydrocarbon. Analysis of guano solids produced measurable concentrations of total petroleum hydrocarbon (TPH) as diesel using both an immunoassay test and the EPA 8015 Modified Method. The testing was conducted on one surface sample of guano collected from a seabird roosting and nesting area. Source species were not identified.more » Positive hydrocarbon test results for guano raise concerns regarding the effectiveness of standard methods of petroleum-contaminated site characterization for Johnston island, other Pacific islands, and coastal areas with historic or contemporary seabird populations.« less

A wall interference assessment/correction system

NASA Technical Reports Server (NTRS)

Lo, Ching F.; Ulbrich, N.; Sickles, W. L.; Qian, Cathy X.

1992-01-01

A Wall Signature method, the Hackett method, has been selected to be adapted for the 12-ft Wind Tunnel wall interference assessment/correction (WIAC) system in the present phase. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating wall interferences at the model location. The Wall Signature method will be formulated for application to the unique geometry of the 12-ft Tunnel. The development and implementation of a working prototype will be completed, delivered and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method-Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected parameters with those for the free-air simulation. Each set of wind tunnel/test article numerical simulations provides data to validate the WIAC method. A numerical wind tunnel test simulation is initiated to validate the WIAC methods developed in the project. In the present reported period, the blockage correction has been developed and implemented for a rectangular tunnel as well as the 12-ft Pressure Tunnel. An improved wall interference assessment and correction method for three-dimensional wind tunnel testing is presented in the appendix.

Radio Frequency Identification (RFID) Based Corrosion Monitoring Sensors. Part 2: Application and Testing of the Coating Materials

DTIC Science & Technology

2014-12-22

Radio frequency identification ( RFID ) based corrosion monitoring sensors: Part II Application and testing of the coating materials Youliang He1...email: yohe@nrcan.gc.ca Keywords: Corrosion monitoring; Wireless sensor; RFID ; Electromagnetic interference; Coating. Abstract Cost-effective...Radio Frequency Identification ( RFID ) transponders (tags) were investigated for wireless corrosion monitoring by applying a metal-filled conductive

Support System Effects on the DLR-F6 Transport Configuration in the National Transonic Facility

NASA Technical Reports Server (NTRS)

Rivers, Melissa B.; Hunter, Craig A.; Gatlin, Gregory M.

2009-01-01

An experimental investigation of the DLR-F6 generic transport configuration was conducted in the NASA NTF for use in the Drag Prediction Workshop. As data from this experimental investigation was collected, a large difference in drag values was seen between the NTF test and an ONERA test that was conducted several years ago. After much investigation, it was determined that this difference was likely due to a sting effect correction applied to the ONERA data which NTF does not use. This insight led to the present work. In this study, a computational assessment has been undertaken to investigate model support system interference effects on the DLR-F6 transport configuration. The configurations computed during this investigation were the isolated wing-body, the wing-body with the full support system (blade and sting), the wing-body with just the blade, and the wing-body with just the sting. The results from this investigation show the same trends that ONERA saw when they conducted a similar experimental investigation in the S2MA tunnel. Computational results suggest that the blade contributed an interference type of effect, the sting contributed a general blockage effect, and the full support system combined these effects.

Experimental study of pressure and heating rate on a swept cylindrical leading edge resulting from swept shock wave interference. M.S. Thesis

NASA Technical Reports Server (NTRS)

Glass, Christopher E.

1989-01-01

The effects of cylindrical leading edge sweep on surface pressure and heat transfer rate for swept shock wave interference were investigated. Experimental tests were conducted in the Calspan 48-inch Hypersonic Shock Tunnel at a nominal Mach number of 8, nominal unit Reynolds number of 1.5 x 10 to the 6th power per foot, leading edge and incident shock generator sweep angles of 0, 15, and 30 deg, and incident shock generator angle-of-attack fixed at 12.5 deg. Detailed surface pressure and heat transfer rate on the cylindircal leading edge of a swept shock wave interference model were measured at the region of the maximum surface pressure and heat transfer rate. Results show that pressure and heat transfer rate on the cylindrical leading edge of the shock wave interference model were reduced as the sweep was increased over the range of tested parameters. Peak surface pressure and heat transfer rate on the cylinder were about 10 and 30 times the undisturbed flow stagnation point value, respectively, for the 0 deg sweep test. A comparison of the 15 and 30 deg swept results with the 0 deg swept results showed that peak pressure was reduced about 13 percent and 44 percent, respectively, and peak heat transfer rate was reduced about 7 percent and 27 percent, respectively.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Test Report, Electromagnetic Interference (EMI)/Electromagnetic Radiation(EMR) and Electromagnetic Capability (EMC) for the EOS/AMSU-A1

NASA Technical Reports Server (NTRS)

Paliwoda, L.

1998-01-01

This document contains the procedure and the test results of the Advanced Microwave Sounding Unit-A (AMSU-A) Earth Observing System (EOS) Project, assembly part number 1356008-1, serial number 202, Electromagnetic Interference (EMI) and Electromagnetic Susceptibility (EMC) qualification test. The test was conducted in accordance with the approved EMI/EMC Test Plan/Procedure, Specification number AE-26151/8B, dated 10 September 1998. Aerojet intends that the presentation and submittal of this document, prepared in accordance with the objectives established by the aforementioned Test Plan/Procedure, document number AE-26151/8B, will satisfy the data requirement with respect to the AMSU-A/EOS instrument operational compliance of the EMI/EMC test requirement. Test for the AMSU-A/EOS instrument have been completed and all the requirements per General Interface Requirement Document (GIRD), GSFC 422-11-12-01, for EOS Common Spacecraft/Instruments, paragraph 10.11, were met with the exceptions of the test methods CE03, RE01, and RE02, as described in this document.

Cognitive load selectively influences the interruptive effect of pain on attention.

PubMed

Moore, David J; Eccleston, Christopher; Keogh, Edmund

2017-10-01

Pain is known to interrupt attentional performance. Such interference effects seem to occur preferentially for tasks that are complex and/or difficult. However, few studies have directly manipulated memory load in the context of pain interference to test this view. Therefore, this study examines the effect of experimental manipulations of both memory load and pain on 3 tasks previously found to be sensitive to pain interference. Three experiments were conducted. A different task was examined in each experiment, each comprising of a high- and low-cognitive load versions of the task. Experiment 1 comprised an attention span (n-back) task, experiment 2 an attention switching task, and experiment 3 a divided attention task. Each task was conducted under painful and nonpainful conditions. Within the pain condition, an experimental thermal pain induction protocol was administered at the same time participants completed the task. The load manipulations were successful in all experiments. Pain-related interference occurred under the high-load condition but only for the attention span task. No effect of pain was found on either the attentional switching or divided attention task. These results suggest that while cognitive load may influence the interruptive effect of pain on attention, this effect may be selective. Because pain affected the high-load version of the n-back task but did not interrupt performance on attentional switching or dual-task paradigms, this means that our findings did not completely support our hypotheses. Future research should explore further the parameters and conditions under which pain-related interference occurs.

Mathematical Modelling of Allelopathy: IV. Assessment of Contributions of Competition and Allelopathy to Interference by Barley

PubMed Central

Liu, De Li; An, Min; Johnson, I.R.; Lovett, J.V.

2005-01-01

One of the main challenges to the research on allelopathy is technically the separation of allelopathic effect from competition, and quantitatively, the assessment of the contribution of each component to overall interference. A simple mathematical model is proposed to calculate the contribution of allelopathy and competition to interference. As an example of applying the quantitative model to interference by barley (Hordeum vulgare cv. Triumph), the approach used was an addition of allelopathic effect, by an equivalent amount, to the environment of the test plant (white mustard, Sinapis alba), rather than elimination of competition. Experiments were conducted in glasshouse to determine the magnitude of the contributions of allelopathy and competition to interference by barley. The leachates of living barley roots significantly reduced the total dry weight of white mustard. The model involved the calculation of adjusted densities to an equivalent basis for modelling the contribution of allelopathy and competition to total interference. The results showed that allelopathy contributed 40%, 37% and 43% to interference by barley at 6, 12 and 18 white mustard pot−1. The consistency in magnitude of the calculated contribution of allelopathic effect by barley across various densities of receiver plant suggested that the adjusted equivalent density is effective and that the model is able to assess the contribution of each component of interference regardless of the density of receiver plant. PMID:19330162

Wall-interference corrections for parachutes in a closed wind tunnel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macha, J.M.; Buffington, R.J.

1989-01-01

An extensive test program was conducted to gather information on wall-interference effects for parachutes in closed wind tunnels. Drag area and base pressure measurements were made for a set of ribbon parachutes of 7%, 15% and 30% geometric porosity in six different wind tunnels, covering a range of geometric blockages from two to thirty-five percent. The resulting data have been used to formulate and validate approximate blockage correction equations based on the theory of Maskell. The corrections are applicable to single parachutes and clusters of two and three parachutes. 8 refs., 7 figs., 1 tab.

Criteria for site selection and frequency allocation (keynote paper), part 5

NASA Technical Reports Server (NTRS)

Rottger, J.

1985-01-01

Technical aspects of mesosphere-stratosphere-troposphere (MST) Radar on site and frequency selection were discussed. Recommendations on site selections are presented. Tests of interference will be conducted before selecting a site. A small directional antenna may be suitable to simulate sidelobe sensitivity of radars however, sophisticated data-processing methods make system sensitivity extremely good. The use of the complete data system to look for interference is recommended. There is the difficulty of allocation of frequencies -- almost continuous use by these radars will be made when the band 40 to 60 MHz is allocated to other services.

Comparison of the analytical capabilities of the BAC Datamaster and Datamaster DMT forensic breath testing devices.

PubMed

Glinn, Michele; Adatsi, Felix; Curtis, Perry

2011-11-01

The State of Michigan uses the Datamaster as an evidential breath testing device. The newest version, the DMT, will replace current instruments in the field as they are retired from service. The Michigan State Police conducted comparison studies to test the analytical properties of the new instrument and to evaluate its response to conditions commonly cited in court defenses. The effects of mouth alcohol, objects in the mouth, and radiofrequency interference on paired samples from drinking subjects were assessed on the DMT. The effects of sample duration and chemical interferents were assessed on both instruments, using drinking subjects and wet-bath simulators, respectively. Our testing shows that Datamaster and DMT results are essentially identical; the DMT gave accurate readings as compared with measurements made using simulators containing standard ethanol solutions and that the DMT did not give falsely elevated breath alcohol results from any of the influences tested. © 2011 American Academy of Forensic Sciences.

Does altercentric interference rely on mentalizing?: Results from two level-1 perspective-taking tasks

PubMed Central

Gollwitzer, Anton; Santos, Laurie R.

2018-01-01

Considerable debate has focused on whether adults possess an implicit system for representing others’ mental states. Some argue that people automatically represent the perspective of others using evidence from altercentric interference—cases in which another agent’s perspective affects the speed with which one can report one’s own perspective. Others have argued that altercentric interference is not always specific to social stimuli and thus may represent a simpler process such as submentalizing. To distinguish between these positions, Study 1 developed a novel measure of altercentric interference—a “sandbox” measure—that allowed us to more sensitively assess altercentric interference across social and non-social conditions. We replicated previous findings showing that participants experience both egocentric and altercentric interference, but we found that these effects emerge equally in social and non-social conditions. To further test whether altercentric interference emerges in social perspective-taking situations, Study 2 conducted a conceptual replication of a study which used a novel “goggle” paradigm to assess whether individuals implicitly represent others’ perspectives. Although we failed to find evidence of altercentric interference in response times, participants’ accuracy reflected the possibility of interference from others’ perspectives. We argue that these findings provide support for the idea that altercentric interference in response to social stimuli (an avatar) is driven by perspective-taking mechanisms, while such interference in response to non-social stimuli (an arrow) is driven by attention-cuing mechanisms. PMID:29566019

Experimental and numerical study of Bondura® 6.6 PIN joints

NASA Astrophysics Data System (ADS)

Berkani, I.; Karlsen, Ø.; Lemu, H. G.

2017-12-01

Pin joints are widely used in heavy-duty machinery such as aircrafts, cranes and offshore drilling equipment to transfer multi-dimensional shear forces. Their strength and service life depend on the clamping force in the contact region that is provided by interference fits. Though the interference fits provide full contact at the pin-hole interface under pretension loads, the contact interface reduces when the pin is subjected to an external load and hence a smaller contact surface leads to dramatic increase of the contact stress. The PIN joint of Bondura® Technology, investigated in this study, is an innovative solution intended to reduce the slack at the contact surface of the pin joint of heavy-duty machinery by using tapered sleeves on each end of the PIN. The study is aimed to better understand the contact pressure build-up and stress distribution in the supporting contact surface under pre-loading of the joint and the influence of temperature difference between part assembly and operation conditions. Numerical simulation using finite element method and diverse experimental tests were conducted. The numerical simulation and the test results, particularly the tests conducted with lubricated joints, show good conformance.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A. Engineering Report: Electromagnetic Interface (EMI)/Electromagnetic Radiation (EMR) and Electromagnetic Compatibility (EMC), for the METSAT/METOP AMSU-A1

NASA Technical Reports Server (NTRS)

Valdez, A.

1999-01-01

This document contains the procedure and the test results of the Advanced Microwave Sounding Unit-A (AMSU-A) Electromagnetic Interference (EMI), Electromagnetic Susceptibility, and Electromagnetic Compatibility (EMC) qualification test for the Meteorological Satellite (METSAT) and the Meteorological Operation Platform (METOP) projects. The test was conducted in accordance with the approved EMI/EMC Test Plan/Procedure, Specification number AE-26151/5D. This document describes the EMI/EMC test performed by Aerojet and it is presented in the following manner: Section-1 contains introductory material and a brief summary of the test results. Section 2 contains more detailed descriptions of the test plan, test procedure, and test results for each type of EMI/EMC test conducted. Section 3 contains supplementary information that includes test data sheets, plots, and calculations collected during the qualification testing.

Phase change paint tests on Rockwell orbiter/tank and orbiter alone configurations (OH3A/OH3B)

NASA Technical Reports Server (NTRS)

Quan, M.; Craig, C.

1974-01-01

Wind tunnel tests were conducted on scale models of the space shuttle orbiter and external tank. The tests were designed to determine the basic heating rate and interference effects on the orbiter-tank configuration and to analyze the effectiveness of the thermal protective system on the reentry vehicle. The phase change paint techniques were used to determine areodynamic heating rates. Oil flow and schlieren photographs were used for flow visualization.

Performativity Pressures at Urban High Schools in Sweden and the USA

ERIC Educational Resources Information Center

Lunneblad, Johannes; Dance, L. Janelle

2014-01-01

This article reveals how test-based performativity pressures interfere with the pedagogical approaches preferred by teachers of second-language learners. Our findings derive from ethnographic research conducted in two non-mainstream high schools: one in a US city and other one in a Swedish city. Both schools serve immigrant students who speak…

Conduction velocity of antigravity muscle action potentials.

PubMed

Christova, L; Kosarov, D; Christova, P

1992-01-01

The conduction velocity of the impulses along the muscle fibers is one of the parameters of the extraterritorial potentials of the motor units allowing for the evaluation of the functional state of the muscles. There are no data about the conduction velocities of antigravity muscleaction potentials. In this paper we offer a method for measuring conduction velocity of potentials of single MUs and the averaged potentials of the interference electromiogram (IEMG) lead-off by surface electrodes from mm. sternocleidomastoideus, trapezius, deltoideus (caput laterale) and vastus medialis. The measured mean values of the conduction velocity of antigravity muscles potentials can be used for testing the functional state of the muscles.

Associations of Adiposity and Aerobic Fitness with Executive Function and Math Performance in Danish Adolescents.

PubMed

Huang, Tao; Tarp, Jakob; Domazet, Sidsel Louise; Thorsen, Anne Kær; Froberg, Karsten; Andersen, Lars Bo; Bugge, Anna

2015-10-01

To examine the associations of adiposity and aerobic fitness with executive function and math performance in Danish adolescents. Cross-sectional analyses were conducted with data on 525 adolescents attending sixth and seventh grades from 14 schools in the 5 main regions of Denmark. A modified Eriksen flanker task was used to assess inhibitory control, a key aspect of executive function. Academic performance was assessed by a customized math test. Aerobic fitness was assessed by an intermittent shuttle-run test (Andersen test). Body mass index (BMI) was negatively associated with accuracy on incongruent trials during the flanker task (P = .005). A higher BMI was associated with a larger accuracy interference score (P = .01). Similarly, waist circumference (WC) was negatively associated with accuracy on incongruent trials (P = .008). A higher WC was associated with a larger reaction time (RT) interference score (P = .02) and accuracy interference score (P = .009). Higher aerobic fitness was associated with a faster RT on congruent trials (P = .009) and incongruent trials (P = .003). Higher aerobic fitness was associated with a smaller RT interference score (P = .04). Aerobic fitness was positively associated with math score (P < .001). BMI and WC were not associated with math score (P > .05). These results suggest that aerobic fitness is positively associated with both inhibitory control and math performance in adolescents. Adiposity is negatively associated with inhibitory control in adolescents. Adiposity is not associated with math performance. Copyright © 2015 Elsevier Inc. All rights reserved.

An Experimental Investigation of Helicopter Rotor Hub Fairing Drag Characteristics

NASA Technical Reports Server (NTRS)

Sung, D. Y.; Lance, M. B.; Young, L. A.; Stroub, R. H.

1989-01-01

A study was done in the NASA 14- by 22-Foot Wind Tunnel at Langley Research Center on the parasite drag of different helicopter rotor hub fairings and pylons. Parametric studies of hub-fairing camber and diameter were conducted. The effect of hub fairing/pylon clearance on hub fairing/pylon mutual interference drag was examined in detail. Force and moment data are presented in tabular and graphical forms. The results indicate that hub fairings with a circular-arc upper surface and a flat lower surface yield maximum hub drag reduction; and clearance between the hub fairing and pylon induces high mutual-interference drag and diminishes the drag-reduction benefit obtained using a hub fairing with a flat lower surface. Test data show that symmetrical hub fairings with circular-arc surfaces generate 74 percent more interference drag than do cambered hub fairings with flat lower surfaces, at moderate negative angle of attack.

36 CFR 331.16 - Interference with government employees.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Interference with government... WILDLIFE CONSERVATION AREA, KENTUCKY AND INDIANA § 331.16 Interference with government employees. Interference with any Government employee in the conduct of his or her official duties pertaining to the...

36 CFR 331.16 - Interference with government employees.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Interference with government... WILDLIFE CONSERVATION AREA, KENTUCKY AND INDIANA § 331.16 Interference with government employees. Interference with any Government employee in the conduct of his or her official duties pertaining to the...

A Comprehensive Well Testing Implementation during Exploration Phase in Rantau Dedap, Indonesia

NASA Astrophysics Data System (ADS)

Humaedi, M. T.; Alfiady; Putra, A. P.; Martikno, R.; Situmorang, J.

2016-09-01

This paper describes the implementation of comprehensive well testing programs during the 2014-2015 exploration drilling in Rantau Dedap Geothermal Field. The well testing programs were designed to provide reliable data as foundation for resource assessment as well as useful information for decision making during drilling. A series of well testing survey consisting of SFTT, completion test, heating-up downhole logging, discharge test, chemistry sampling was conducted to understand individual wells characteristics such as thermodynamic state of the reservoir fluid, permeability distribution, well output and fluid chemistry. Furthermore, interference test was carried out to investigate the response of reservoir to exploitation.

A Novel Transient Fault Current Sensor Based on the PCB Rogowski Coil for Overhead Transmission Lines

PubMed Central

Liu, Yadong; Xie, Xiaolei; Hu, Yue; Qian, Yong; Sheng, Gehao; Jiang, Xiuchen

2016-01-01

The accurate detection of high-frequency transient fault currents in overhead transmission lines is the basis of malfunction detection and diagnosis. This paper proposes a novel differential winding printed circuit board (PCB) Rogowski coil for the detection of transient fault currents in overhead transmission lines. The interference mechanism of the sensor surrounding the overhead transmission line is analyzed and the guideline for the interference elimination is obtained, and then a differential winding printed circuit board (PCB) Rogowski coil is proposed, where the branch and return line of the PCB coil were designed to be strictly symmetrical by using a joining structure of two semi-rings and collinear twisted pair differential windings in each semi-ring. A serial test is conducted, including the frequency response, linearity, and anti-interference performance as well as a comparison with commercial sensors. Results show that a PCB Rogowski coil has good linearity and resistance to various external magnetic field interferences, thus enabling it to be widely applied in fault-current-collecting devices. PMID:27213402

Reduced Interference from Memory Testing: A Postretrieval Monitoring Account

ERIC Educational Resources Information Center

Pierce, Benton H.; Gallo, David A.; McCain, Jason L.

2017-01-01

Initial learning can interfere with subsequent learning (proactive interference [PI]), but recent work indicates initial testing can reduce PI. Here, we tested 2 alternative hypotheses of this effect: Does testing reduce PI by constraining retrieval to the target list, or by facilitating a postretrieval monitoring process? Participants first…

Aerodynamic investigations into various low speed L/D improvement devices on the 140A/B space shuttle orbiter configuration in the Rockwell International low speed wind tunnel (OA86)

NASA Technical Reports Server (NTRS)

Mennell, R. C.

1974-01-01

Tests were conducted to investigate various base drag reduction techniques in an attempt to improve Orbiter lift-to-drag ratios and to calculate sting interference effects on the Orbiter aerodynamic characteristics. Test conditions and facilites, and model dimensional data are presented along with the data reduction guidelines and data set/run number collation used for the studies. Aerodynamic force and moment data and the results of stability and control tests are also given.

Analysis of the selected mechanical parameters of coating of filters protecting against hazardous infrared radiation.

PubMed

Gralewicz, Grzegorz; Owczarek, Grzegorz; Kubrak, Janusz

2017-03-01

This article presents a comparison of the test results of selected mechanical parameters (hardness, Young's modulus, critical force for delamination) for protective filters intended for eye protection against harmful infrared radiation. Filters with reflective metallic films were studied, as well as interference filters developed at the Central Institute for Labour Protection - National Research Institute (CIOP-PIB). The test results of the selected mechanical parameters were compared with the test results, conducted in accordance with a standardised method, of simulating filter surface destruction that occurs during use.

Evaluation of Mobile Phone Interference With Aircraft GPS Navigation Systems

NASA Technical Reports Server (NTRS)

Pace, Scott; Oria, A. J.; Guckian, Paul; Nguyen, Truong X.

2004-01-01

This report compiles and analyzes tests that were conducted to measure cell phone spurious emissions in the Global Positioning System (GPS) radio frequency band that could affect the navigation system of an aircraft. The cell phone in question had, as reported to the FAA (Federal Aviation Administration), caused interference to several GPS receivers on-board a small single engine aircraft despite being compliant with data filed at the time with the FCC by the manufacturer. NASA (National Aeronautics and Space Administration) and industry tests show that while there is an emission in the 1575 MHz GPS band due to a specific combination of amplifier output impedance and load impedance that induces instability in the power amplifier, these spurious emissions (i.e., not the intentional transmit signal) are similar to those measured on non-intentionally transmitting devices such as, for example, laptop computers. Additional testing on a wide sample of different commercial cell phones did not result in any emission in the 1575 MHz GPS Band above the noise floor of the measurement receiver.

Electromagnetic interference with pacemakers caused by portable media players.

PubMed

Thaker, Jay P; Patel, Mehul B; Jongnarangsin, Krit; Liepa, Valdis V; Thakur, Ranjan K

2008-04-01

Electromagnetic fields generated by electrical devices may cause interference with permanent pacemakers. Media players are becoming a common mode of portable entertainment. The most common media players used worldwide are iPods. These devices are often carried in a shirt chest pocket, which may place the devices close to an implanted pacemaker. The purpose of this study was to determine if iPods cause interference with pacemakers. In this prospective, single-blinded study, 100 patients who had cardiac pacemakers were tested with four types of iPods to assess for interference. Patients were monitored by a single-channel ECG monitor as well as the respective pacemaker programmer via the telemetry wand. iPods were tested by placing them 2 inches anterior to the pacemaker and wand for up to 10 seconds. To simulate actual use, standard-issue headphones were plugged into the iPods. To maintain consistency, the volume was turned up maximally, and the equalizer was turned off. A subset of 25 patients underwent testing on 2 separate days to assess for reproducibility of interference. Pacemaker interference was categorized as type I or type II telemetry interference. Type I interference was associated with atrial and/or ventricular high rates on rate histograms. Type II interference did not affect pacemaker rate counters. Electromagnetic emissions from the four iPods also were evaluated in a Faraday cage to determine the mechanism of the observed interference. One hundred patients (63 men and 37 women; mean age 77.1 +/- 7.6 years) with 11 single-chamber pacemakers and 89 dual-chamber pacemakers underwent 800 tests. The incidence of any type of interference was 51% of patients and 20% of tests. Type I interference was seen in 19% of patients and type II in 32% of patients. Reproducibility testing confirmed that interference occurred regardless of pacing configuration (unipolar or bipolar), pacing mode (AAI, VVI, or DDD), and from one day to the next. Electromagnetic emissions testing from the iPods demonstrated maximum emissions in the pacemaker carrier frequency range when the iPod was turned "on" with the headphones attached. iPods placed within 2 inches of implanted pacemakers monitored via the telemetry wand can cause interference with pacemakers.

When instructions fail. The effects of stimulus control training on brain injury survivors' attending and reporting during hearing screenings.

PubMed

Schlund, M W

2000-10-01

Bedside hearing screenings are routinely conducted by speech and language pathologists for brain injury survivors during rehabilitation. Cognitive deficits resulting from brain injury, however, may interfere with obtaining estimates of auditory thresholds. Poor comprehension or attention deficits often compromise patient abilities to follow procedural instructions. This article describes the effects of jointly applying behavioral methods and psychophysical methods to improve two severely brain-injured survivors' attending and reporting on auditory test stimuli presentation. Treatment consisted of stimulus control training that involved differentially reinforcing responding in the presence and absence of an auditory test tone. Subsequent hearing screenings were conducted with novel auditory test tones and a common titration procedure. Results showed that prior stimulus control training improved attending and reporting such that hearing screenings were conducted and estimates of auditory thresholds were obtained.

EMI survey for maritime satellite 1535-1645-MHz shipboard terminal

NASA Technical Reports Server (NTRS)

Taylor, R. E.; Brandel, D. L.; Hill, J. S.

1977-01-01

A 15,690-ton commercial container ship was selected as lead ship for an onboard electromagnetic-interference (EMI) survey prior to installation of 1535-1645-MHz (L-Band) shipboard terminals for communication via a maritime satellite. In general, the EMI survey revealed tolerable interference levels on board ship. Radiometer measurements indicate antenna-noise temperatures less than 70 K at elevation angles of 5 deg and greater at 1559 MHz at the output terminals of the 1.2-m diameter parabolic-dish antenna for the L-band shipboard terminal. Other EMI measurements include field intensity from 3-cm and 10-cm wavelength pulse radars, and conducted-emission tests of primary power lines to both onboard radars.

Computerized Testing Software for Assessing Interference Suppression in Children and Adults: The Bivalent Shape Task (BST)

PubMed Central

Mueller, Shane T.; Esposito, Alena G.

2015-01-01

We describe the Bivalent Shape Task (BST), software using the Psychology Experiment Building Language (PEBL), for testing of cognitive interference and the ability to suppress interference. The test is available via the GNU Public License, Version 3 (GPLv3), is freely modifiable, and has been tested on both children and adults and found to provide a simple and fast non-verbal measure of cognitive interference and suppression that requires no reading. PMID:26702358

International Symposium on Electromagnetic Compatibility, 25th, Arlington, VA, August 23-25, 1983, Symposium Record

NASA Astrophysics Data System (ADS)

Subjects related to electromagnetic compatibility (EMC) analysis are discussed, taking into account forcing terms of line equations for externally excited transmission lines, E-fields over ground, electromagnetic near fields as a function of electrical size, a program for experimental verification of EMC analysis models, random susceptability of an IC 7400 TTL NAND gate, and a comparison of IEMCAP and SEMCAP. Other topics explored are concerned with EMC measurements, spectrum management, the electromagnetic pulse (EMP), a Navy EMC program, measurement systems, filters, EMC design, electromagnetic vulnerability (EMV) assessment of weapon systems, FCC rules and regulations, shielding, and electromagnetic interference (EMI) in communication systems. Attention is also given to nonsinusoidal functions in radar and communications, transients/electrostatic discharge, open field testing, cables and connectors, interference effects of induced and conducted earth current at dc and ELF, test cells, and cable coupling.

The effects on cruise drag of installing long-duct refan-engine nacelles on the McDonnell Douglas DC-8-50 and -61

NASA Technical Reports Server (NTRS)

Callaghan, J. T.; Donelson, J. E.; Morelli, J. P.

1973-01-01

A high-speed wind tunnel test was conducted to determine the effect on cruise performance of installing long-duct refan-engine nacelles on the DC-8-50 and -61 models. Drag data and wing/pylon/nacelle channel pressure data are presented. At a typical cruise condition there exists a very small interference drag penalty of less than one-percent of total cruise data for the Refan installation. Pressure data indicate that some supersonic flow is present in the inboard channel of the inboard refan nacelle installation, but it is not sufficient to cause any wave drag on boundary layer separation. One pylon modification, which takes the form of pylon bumps, was tested. It resulted in a drag penalty, because its design goal of eliminating shock-related interference drag was not required and the bump thus became a source of additional parasite drag.

Description and evaluation of an interference assessment for a slotted-wall wind tunnel

NASA Technical Reports Server (NTRS)

Kemp, William B., Jr.

1991-01-01

A wind-tunnel interference assessment method applicable to test sections with discrete finite-length wall slots is described. The method is based on high order panel method technology and uses mixed boundary conditions to satisfy both the tunnel geometry and wall pressure distributions measured in the slotted-wall region. Both the test model and its sting support system are represented by distributed singularities. The method yields interference corrections to the model test data as well as surveys through the interference field at arbitrary locations. These results include the equivalent of tunnel Mach calibration, longitudinal pressure gradient, tunnel flow angularity, wall interference, and an inviscid form of sting interference. Alternative results which omit the direct contribution of the sting are also produced. The method was applied to the National Transonic Facility at NASA Langley Research Center for both tunnel calibration tests and tests of two models of subsonic transport configurations.

Grounding and Shielding Requirements for the Radiation and EMP Environments of an Underground Nuclear Test

DTIC Science & Technology

1978-03-17

the trailers as Electro-magnetic Interference ( EMI ) tight as possible; such items included removal of all unnecessary wiring penetrations, conductive...20 12. CABLE TRAYS, GROUT-FILLED ............ .................. 21 13. THE MESA TRAILER PARK CONSIDERATIONS...enclosed cable shields. 12. The mesa trailer park received some attention regarding the GSP, although not as intense as the tunnel environment. Specifically

Effects of axisymmetric and normal air jet plumes and solid plume on cylindrical afterbody pressure distributions at Mach numbers from 1.65 to 2.50

NASA Technical Reports Server (NTRS)

Covell, P. F.

1982-01-01

A wind tunnel investigation of the interference effects of axisymmetric nozzle air plumes, a solid plume, and normal air jet plumes on the afterbody pressure distributions and base pressures of a cylindrical afterbody model was conducted at Mach numbers from 1.65 to 2.50. The axisymmetric nozzles, which varied in exit lip Mach number from 1.7 to 2.7, and the normal air jet nozzle were tested at jet pressure ratios from 1 (jet off) to 615. The tests were conducted at an angle of attack of 0 deg and a Reynolds number per meter of 6.56 million. The results of the investigation show that the solid plume induces greater interference effects than those induced by the axisymmetric nozzle plumes at the selected underexpanded design conditions. A thrust coefficient parameter based on nozzle lip conditons was found to correlate the afterbody disturbance distance and the base pressure between the different axisymmetric nozzles. The normal air jet plume and the solid plume induce afterbody disturbance distances similar to those induced by the axisymmetric air plumes when base pressure is held constant.

Comparison of an Ultrasonic Phased Array Evaluation with Destructive Analysis of a Documented Leak Path in a Nozzle Removed from Service

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cinson, Anthony D.; Crawford, Susan L.; MacFarlan, Paul J.

2012-09-24

Non-destructive and destructive testing methods were employed to evaluate a documented boric acid leakage path through an Alloy 600 control rod drive mechanism (CRDM) penetration from the North Anna Unit 2 reactor pressure vessel head that was removed from service in 2002. A previous ultrasonic in-service-inspection (ISI) conducted by industry prior to the head removal, identified a probable leakage path in Nozzle 63 located in the interference fit between the penetration tube and the vessel head. In this current examination, Nozzle 63 was examined using phased array (PA) ultrasonic testing with a 5.0-MHz, eight-element annular array; immersion data were acquiredmore » from the nozzle inner diameter (ID) surface. A variety of focal laws were employed to evaluate the signal responses from the interference fit region. These responses were compared to responses obtained from a mockup specimen that was used to determine detection limits and characterization capabilities for wastage and boric acid presence in the interference fit region. Nozzle 63 was destructively examined after the completion of the ultrasonic nondestructive evaluation (NDE) to visually assess the leak paths. These destructive and nondestructive results compared favorably« less

Stroop Color-Word Interference Test: Normative data for the Latin American Spanish speaking adult population.

PubMed

Rivera, D; Perrin, P B; Stevens, L F; Garza, M T; Weil, C; Saracho, C P; Rodríguez, W; Rodríguez-Agudelo, Y; Rábago, B; Weiler, G; García de la Cadena, C; Longoni, M; Martínez, C; Ocampo-Barba, N; Aliaga, A; Galarza-Del-Angel, J; Guerra, A; Esenarro, L; Arango-Lasprilla, J C

2015-01-01

To generate normative data on the Stroop Test across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and, Puerto Rico. Each subject was administered the Stroop Test, as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. The final multiple linear regression models explained 14-36% of the variance in Stroop Word scores, 12-41% of the variance in the Stoop Color, 14-36% of the variance in the Stroop Word-Color scores, and 4-15% of variance in Stroop Interference scores. Although t-tests showed significant differences between men and women on the Stroop test, none of the countries had an effect size larger than 0.3. As a result, gender-adjusted norms were not generated. This is the first normative multicenter study conducted in Latin America to create norms for the Stoop Test in a Spanish-Speaking sample. This study will therefore have important implications for the future of neuropsychology research and practice throughout the region.

Test and control computer user's guide for a digital beam former test system

NASA Technical Reports Server (NTRS)

Alexovich, Robert E.; Mallasch, Paul G.

1992-01-01

A Digital Beam Former Test System was developed to determine the effects of noise, interferers and distortions, and digital implementations of beam forming as applied to the Tracking and Data Relay Satellite 2 (TDRS 2) architectures. The investigation of digital beam forming with application to TDRS 2 architectures, as described in TDRS 2 advanced concept design studies, was conducted by the NASA/Lewis Research Center for NASA/Goddard Space Flight Center. A Test and Control Computer (TCC) was used as the main controlling element of the digital Beam Former Test System. The Test and Control Computer User's Guide for a Digital Beam Former Test System provides an organized description of the Digital Beam Former Test System commands. It is written for users who wish to conduct tests of the Digital Beam forming Test processor using the TCC. The document describes the function, use, and syntax of the TCC commands available to the user while summarizing and demonstrating the use of the commands wtihin DOS batch files.

Electromagnetic interference in electrical systems of motor vehicles

NASA Astrophysics Data System (ADS)

Dziubiński, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

2016-09-01

Electronic ignition system affects the electronic equipment of the vehicle by electric and magnetic fields. The measurement of radio electromagnetic interference originating from the ignition system affecting the audiovisual test bench was carried out with a variable speed of the ignition system. The paper presents measurements of radio electromagnetic interference in automobiles. In order to determine the level of electromagnetic interference, the audiovisual test bench was equipped with a set of meters for power consumption and assessment of the level of electromagnetic interference. Measurements of the electromagnetic interference level within the audiovisual system were performed on an experimental test bench consisting of the ignition system, starting system and charging system with an alternator and regulator.

Cellular telephone interference with medical equipment.

PubMed

Tri, Jeffrey L; Severson, Rodney P; Firl, Allen R; Hayes, David L; Abenstein, John P

2005-10-01

To assess the potential electromagnetic interference (EMI) effects that new or current-generation cellular telephones have on medical devices. For this study, performed at the Mayo Clinic in Rochester, Minn, between March 9, 2004, and April 24, 2004, we tested 16 different medical devices with 6 cellular telephones to assess the potential for EMI. Two of the medical devices were tested with both new and old interface modules. The 6 cellular telephones chosen represent the different cellular technology protocols in use: Code Division Multiple Access (2 models), Global System for Mobile communications, Integrated Digital Enhanced Network, Time Division Multiple Access, and analog. The cellular telephones were tested when operating at or near their maximum power output. The medical devices, connected to clinical simulators during testing, were monitored by observing the device displays and alarms. Of 510 tests performed, the incidence of clinically important interference was 1.2%; EMI was Induced in 108 tests (21.2%). Interference occurred in 7 (44%) of the 16 devices tested. Cellular telephones can interfere with medical equipment. Technology changes in both cellular telephones and medical equipment may continue to mitigate or may worsen clinically relevant interference. Compared with cellular telephones tested in previous studies, those currently in use must be closer to medical devices before any interference is noticed. However, periodic testing of cellular telephones to determine their effects on medical equipment will be required.

Tuning the thermal conductance of molecular junctions with interference effects

NASA Astrophysics Data System (ADS)

Klöckner, J. C.; Cuevas, J. C.; Pauly, F.

2017-12-01

We present an ab initio study of the role of interference effects in the thermal conductance of single-molecule junctions. To be precise, using a first-principles transport method based on density functional theory, we analyze the coherent phonon transport in single-molecule junctions made of several benzene and oligo(phenylene ethynylene) derivatives. We show that the thermal conductance of these junctions can be tuned via the inclusion of substituents, which induces destructive interference effects and results in a decrease of the thermal conductance with respect to the unmodified molecules. In particular, we demonstrate that these interference effects manifest as antiresonances in the phonon transmission, whose energy positions can be tuned by varying the mass of the substituents. Our work provides clear strategies for the heat management in molecular junctions and, more generally, in nanostructured metal-organic hybrid systems, which are important to determine how these systems can function as efficient energy-conversion devices such as thermoelectric generators and refrigerators.

Focal ratio degradation and transmission in VIRUS-P optical fibers

NASA Astrophysics Data System (ADS)

Murphy, Jeremy D.; MacQueen, Phillip J.; Hill, Gary J.; Grupp, Frank; Kelz, Andreas; Palunas, Povilas; Roth, Martin; Fry, Alexander

2008-07-01

We have conducted extensive tests of both transmission and focal ratio degradation (FRD) on two integral field units currently in use on the VIRUS-P integral field spectrograph. VIRUS-P is a prototype for the VIRUS instrument proposed for the Hobby-Eberly Telescope at McDonald Observatory. All tests have been conducted at an input f-ratio of F/3.65 and with an 18% central obscuration in order to simulate optical conditions on the HET. Transmission measurements were conducted with narrow-band interference filters (FWHM: 10 nm) at 10 discrete wavelengths (337 to 600 nm), while FRD tests were made at 365 nm, 400 nm and 600 nm. The influence of wavelength, end immersion, fiber type and length on both FRD and transmission is explored. Most notably, we find no wavelength dependence on FRD down to 365 nm. All fibers tested are within the VIRUS instrument specifications for both FRD and transmission. We present the details of our differential FRD testing method and explain a simple and robust technique of aligning the test bench and optical fiber axes to within +/-0.1 degrees.

Release from output interference in recognition memory: A test of the attention hypothesis.

PubMed

Criss, Amy H; Salomão, Cristina; Malmberg, Kenneth J; Aue, William; Kılıç, Aslı; Claridge, MarkAvery

2018-05-01

Retrieval results in both costs and benefits to episodic memory. Output interference (OI) refers to the finding that episodic memory accuracy decreases with increasing test trials. Release from OI is the restoration of original accuracy at some point during the test. For example, a release from OI in recognition memory testing occurs when the semantic similarity between stimuli decreases midway through testing, suggesting that item representations stored on early trials cause interference on tests occurring on later trials to the extent that the earlier items share features with the latter items. In two recognition memory experiments, we demonstrate release from OI for words and faces. We also test whether release from OI is the result of interference or is due to a boost in attention caused by reorienting to a novel stimulus type. A test for the foils presented during the initial test list supports the interference account of OI. Implications for models of memory are discussed.

Conducted Transients on Spacecraft Primary Power Lines

NASA Technical Reports Server (NTRS)

Mc Closkey, John; Dimov, Jen

2017-01-01

One of the sources of potential interference on spacecraft primary power lines is that of conducted transients resulting from equipment being switched on and off of the bus. Susceptibility to such transients is addressed by some version of the CS06 requirement of MIL-STD-461462. This presentation provides a summary of the history of the CS06 requirement and test method, a basis for understanding of the sources of these transients, analysis techniques for determining their worst-case characteristics, and guidelines for minimizing their magnitudes and applying the requirement appropriately.

Using a simulation model to assess risk of false negative point-of-care urinary human chorionic gonadotropin device results due to high-dose hook interference.

PubMed

Milhorn, Denise; Korpi-Steiner, Nichole

2015-02-01

It is unclear if the point-of-care (POC) Clinitest hCG device is subject to high-dose hook interference from physiological concentrations of intact human chorionic gonadotropin (hCG), β-core fragment of hCG (hCGβcf), and hCG free β-subunit (hCGβ) found in urine during pregnancy. We used a simulation model to address this question and related our findings to our institution's pregnant population in order to assess risk for potential false-negative hCG results. The expected distribution of days relative to ovulation during routine POC hCG testing was estimated from 182 patients. Clinitest-Clinitek Status hCG device susceptibility to high-dose hook interference from hCG variants and potential risk of false-negative results as it relates to this population were evaluated by testing increasing concentrations of hCG, hCGβcf, hCGβ as well as urine simulating physiological hCG, hCGβcf and hCGβ concentrations expected during early pregnancy (≤44 days post-ovulation). The Clinitest-Clinitek Status hCG device exhibited high-dose hook interference from hCGβcf alone, but not from hCG, hCGβ, or simulated physiological urinary concentrations of combined hCG, hCGβcf and hCGβ expected during early pregnancy. The majority of our patient population had urinary hCG testing conducted during early pregnancy. The Clinitest-Clinitek Status hCG device is unlikely to exhibit false-negative urinary hCG results due to high-dose hook interference for women in early healthy pregnancy, although additional studies are necessary to determine potential risk in other patient populations. Visual interpretation of POC urinary hCG device results is an important failure mode to consider in risk analyses for erroneous urinary hCG device results. Published by Elsevier Inc.

Conductive Interference in Rapid Transit Signaling Systems. Volume 1. Theory and Data.

DOT National Transportation Integrated Search

1985-11-01

The purpose of this report is to summarize the results of a comprehensive program that has been pursued to delineate all aspects of conductive interference (CI) in rail transit systems and to help avoid its effects in new rail transit systems. The re...

Aerodynamic braking of high speed ground transportation vehicles.

NASA Technical Reports Server (NTRS)

Marte, J. E.; Marko, W. J.

1973-01-01

The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

Experience with duplex bearings in narrow angle oscillating applications

NASA Technical Reports Server (NTRS)

Phinney, D. D.; Pollard, C. L.; Hinricks, J. T.

1988-01-01

Duplex ball bearings are matched pairs on which the abutting faces of the rings have been accurately ground so that when the rings are clamped together, a controlled amount of interference (preload) exists across the balls. These bearings are vulnerable to radial temperature gradients, blocking in oscillation and increased sensitivity to contamination. These conditions decrease the service life of these bearings. It was decided that an accelerated thermal vacuum life test should be conducted. The test apparatus and results are described and the rationale is presented for reducing a multiyear life test on oil lubricated bearings to less than a year.

Psychosocial factors in GP work: the effects of taking a GP position or leaving GP work.

PubMed

Heponiemi, Tarja; Kouvonen, Anne; Aalto, Anna-Mari; Elovainio, Marko

2013-06-01

We examined the effects of leaving public sector general practitioner (GP) work and of taking a GP position on changes in work-related psychosocial factors, such as time pressure, patient-related stress, distress and work interference with family. In addition, we examined whether changes in time pressure and patient-related stress mediated the association of employment change with changes of distress and work interference with family. Participants were 1705 Finnish physicians (60% women) who responded to surveys in 2006 and 2010. Analyses of covariance were conducted to examine the effect of employment change to outcome changes adjusted for gender, age and response format. Mediational effects were tested following the procedures outlined by Baron and Kenny. Employment change was significantly associated with all the outcomes. Leaving public sector GP work was associated with substantially decreased time pressure, patient-related stress, distress and work interference with family. In contrast, taking a position as a public sector GP was associated with an increase in these factors. Mediation tests suggested that the associations of employment change with distress change and work interference with family change were partially explained by the changes in time pressure and patient-related stress. Our results showed that leaving public sector GP work is associated with favourable outcomes, whereas taking a GP position in the public sector is associated with adverse effects. Primary health-care organizations should pay more attention to the working conditions of their GPs, in particular, to time pressure and patient-related stress.

How to Be Proactive About Interference: Lessons From Animal Memory

PubMed Central

Wright, Anthony A.; Katz, Jeffrey S.; Ma, Wei Ji

2015-01-01

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed. PMID:22491142

How to be proactive about interference: lessons from animal memory.

PubMed

Wright, Anthony A; Katz, Jeffrey S; Ma, Wei Ji

2012-05-01

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed.

The role of visual imagery in the retention of information from sentences.

PubMed

Drose, G S; Allen, G L

1994-01-01

We conducted two experiments to evaluate a multiple-code model for sentence memory that posits both propositional and visual representational systems. Both sentences involved recognition memory. The results of Experiment 1 indicated that subjects' recognition memory for concrete sentences was superior to their recognition memory for abstract sentences. Instructions to use visual imagery to enhance recognition performance yielded no effects. Experiment 2 tested the prediction that interference by a visual task would differentially affect recognition memory for concrete sentences. Results showed the interference task to have had a detrimental effect on recognition memory for both concrete and abstract sentences. Overall, the evidence provided partial support for both a multiple-code model and a semantic integration model of sentence memory.

Proactive effects of memory in young and older adults: The role of change recollection

PubMed Central

Wahlheim, Christopher N.

2015-01-01

Age-related deficits in episodic memory are sometimes attributed to older adults being more susceptible to proactive interference. These deficits have been explained by impaired abilities to inhibit competing information and to recollect target information. In the present article, I propose that a change recollection deficit also contributes to age differences in proactive interference. Change recollection occurs when individuals can remember how information changed across episodes, and this counteracts proactive interference by preserving the temporal order of information. Three experiments were conducted to determine whether older adults are less likely to counteract proactive interference by recollecting change. Paired-associate learning paradigms with two lists of word pairs included pairs that repeated across lists, pairs that only appeared in List 2 (control items), and pairs with cues that repeated and responses that changed across lists. Young and older adults’ abilities to detect changed pairs in List 2 and to later recollect those changes at test were measured, along with cued recall of the List 2 responses and confidence in recall performance. Change recollection produced proactive facilitation in the recall of changed pairs, whereas the failure to recollect change resulted in proactive interference. Confidence judgments were sensitive to these effects. The critical finding was that older adults recollected change less than did young adults, and this partially explained older adults’ greater susceptibility to proactive interference. These findings have theoretical implications, showing that a change recollection deficit contributes to age-related deficits in episodic memory. PMID:24710672

Proactive effects of memory in young and older adults: the role of change recollection.

PubMed

Wahlheim, Christopher N

2014-08-01

Age-related deficits in episodic memory are sometimes attributed to older adults being more susceptible to proactive interference. These deficits have been explained by impaired abilities to inhibit competing information and to recollect target information. In the present article, I propose that a change recollection deficit also contributes to age differences in proactive interference. Change recollection occurs when individuals can remember how information changed across episodes, and this counteracts proactive interference by preserving the temporal order of information. Three experiments were conducted to determine whether older adults are less likely to counteract proactive interference by recollecting change. Paired-associate learning paradigms with two lists of word pairs included pairs that repeated across lists, pairs that only appeared in List 2 (control items), and pairs with cues that repeated and responses that changed across lists. Young and older adults' abilities to detect changed pairs in List 2 and to later recollect those changes at test were measured, along with cued recall of the List 2 responses and confidence in recall performance. Change recollection produced proactive facilitation in the recall of changed pairs, whereas the failure to recollect change resulted in proactive interference. Confidence judgments were sensitive to these effects. The critical finding was that older adults recollected change less than did young adults, and this partially explained older adults' greater susceptibility to proactive interference. These findings have theoretical implications, showing that a change recollection deficit contributes to age-related deficits in episodic memory.

Wind tunnel wall interference

NASA Technical Reports Server (NTRS)

Newman, Perry A.; Mineck, Raymond E.; Barnwell, Richard W.; Kemp, William B., Jr.

1986-01-01

About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.

Experimental study of main rotor/tail rotor/airframe interactions in hover. Volume 1: Text and figures

NASA Technical Reports Server (NTRS)

Balch, D. T.; Saccullo, A.; Sheehy, T. W.

1983-01-01

To assist in identifying and quantifying the relevant parameters associated with the complex topic of main rotor/fuselage/tail rotor interference, a model scale hover test was conducted in the Model Rotor Hover Facility. The test was conducted using the basic model test rig, fuselage skins to represent a UH-60A BLACK HAWK helicopter, 4 sets of rotor blades of varying geometry (i.e., twist, airfoils and solidity) and a model tail rotor that could be relocated to give changes in rotor clearance (axially, laterally, and vertically), can't angle and operating model (pusher or tractor). The description of the models and the tests, data analysis and summary (including plots) are included. The customary system of units gas used for principal measurements and calculations. Expressions in both SI units and customary units are used with the SI units stated first and the customary units afterwords, in parenthesis.

Reducing Electromagnetic Interference in a Grid Tied Single Phase Power Inverter

DTIC Science & Technology

2016-09-01

ELECTROMAGNETIC INTERFERENCE IN A GRID TIED SINGLE PHASE POWER INVERTER by Jason Hassan Valiani September 2016 Thesis Advisor: Giovanna Oriti...3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE REDUCING ELECTROMAGNETIC INTERFERENCE IN A GRID TIED SINGLE PHASE POWER...explored. The primary goal is to understand the effects each modulation strategy has on the conducted electromagnetic interference (EMI) and then

Test techniques: A survey paper on cryogenic tunnels, adaptive wall test sections, and magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Kilgore, Robert A.; Dress, David A.; Wolf, Stephen W. D.; Britcher, Colin P.

1989-01-01

The ability to get good experimental data in wind tunnels is often compromised by things seemingly beyond our control. Inadequate Reynolds number, wall interference, and support interference are three of the major problems in wind tunnel testing. Techniques for solving these problems are available. Cryogenic wind tunnels solve the problem of low Reynolds number. Adaptive wall test sections can go a long way toward eliminating wall interference. A magnetic suspension and balance system (MSBS) completely eliminates support interference. Cryogenic tunnels, adaptive wall test sections, and MSBS are surveyed. A brief historical overview is given and the present state of development and application in each area is described.

An integrated approach to characterization of fractured reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datta-Gupta, A.; Majer, E.; Vasco, D.

1995-12-31

This paper summarizes an integrated hydrologic and seismic characterization of a fractured limestone formation at the Conoco Borehole Test Facility (CBTF) in Kay County, Oklahoma. Transient response from pressure interference tests were first inverted in order to identify location and orientation of dominant fractures at the CBTF. Subsequently, high resolution (1000 to 10000 Hz) cross-well and single-well seismic surveys were conducted to verify the preferential slow paths indicated by hydrologic analysis. Seismic surveys were conducted before and after an air injection in order to increase the visibility of the fracture zone to seismic imaging. Both Seismic and hydrologic analysis weremore » found to yield consistent results in detecting the location of a major fracture zone.« less

Reducing Retroactive Interference through the Use of Different Encoding Techniques: An Exploration of Pre-Test/Post-Test Analyses

ERIC Educational Resources Information Center

Cumming, John M.; De Miranda, Michael A.

2012-01-01

Retroactive interference (RI) in list learning occurs when the learning of a second list of words interferes with the recall of the first learned list. Having the lists be thematically different can reduce retroactive interference within list learning; however, this study demonstrates how RI can be reduced when the lists contain similar words.…

Interspecific competition between Solenopsis invicta and two native ant species, Pheidole fervens and Monomorium chinense.

PubMed

Chen, Yin-Cheng; Kafle, Lekhnath; Shih, Cheng-Jen

2011-04-01

This study was designed to understand the effects of the interspecific competition between red imported fire ant, Solenopsis invicta Buren and two native ant species, Pheidole fervens Smith and Monomorium chinense Santschi, by conducting colony interference and individual confrontation tests under laboratory conditions. The colony interference test showed that both native ant species, owing to their numerical advantage, killed the Solenopsis invicta virus-1 (SINV-1)-infected or healthy queens of S. invicta. Significantly less time was required for M. chinense to kill all SINV-1-infected S. invicta compared with the time required to kill the healthy S. invicta. Compared with healthy S. invicta, SINV-1-infected S. invicta spent a longer time eliminating the P. fervens colonies. In confrontation tests, M. chinense killed a significantly higher number of infected S. invicta minors than they did healthy minors, but the number of S. invicta majors (either infected or healthy) killed was substantially less. This study found that the viral infection weakened the competitive ability of S. invicta and made them prone to be eliminated by M. chinense but not by P. fervens.

Second Language Interference during First Language Processing by Arabic–English Bilinguals

PubMed Central

Alsaigh, Tahani; Kennison, Shelia M.

2017-01-01

The research investigated whether a bilinguals’ second language (L2) is activated during a task involving only the first language (L1). We tested the hypothesis that the amount of L2 interference can vary across settings, with less interference occurring in testing locations where L2 is rarely used. In Experiment 1, we compared language processing for 50 Arabic–English bilinguals tested in Saudi Arabia and 49 Arabic–English tested in the United States. In the task, participants viewed a picture and judged whether a phoneme presented over headphones was part of the L1 picture name. The results showed no effect of testing location on processing. For both groups of bilinguals, we observed L2 interference in mean error rates, but not in mean response times. We also found evidence for L2 interference in correlational analyses between response times and (a) participants’ weekly L2 usage and (b) frequency of English picture names. A second experiment with 24 Arabic monolinguals supported the conclusion that the results with bilinguals were due to L2 interference. Implications for theories of bilingual memory are discussed. PMID:29163322

Stroop interference associated with efficient reading fluency and prelexical orthographic processing.

PubMed

Mano, Quintino R; Williamson, Brady J; Pae, Hye K; Osmon, David C

2016-01-01

The Stroop Color-Word Test involves a dynamic interplay between reading and executive functioning that elicits intuitions of word reading automaticity. One such intuition is that strong reading skills (i.e., more automatized word reading) play a disruptive role within the test, contributing to Stroop interference. However, evidence has accumulated that challenges this intuition. The present study examined associations among Stroop interference, reading skills (i.e., isolated word identification, grapheme-to-phoneme mapping, phonemic awareness, reading fluency) measured on standardized tests, and orthographic skills measured on experimental computerized tasks. Among university students (N = 152), correlational analyses showed greater Stroop interference to be associated with (a) relatively low scores on all standardized reading tests, and (b) longer response latencies on orthographic tasks. Hierarchical regression demonstrated that reading fluency and prelexical orthographic processing predicted unique and significant variance in Stroop interference beyond baseline rapid naming. Results suggest that strong reading skills, including orthographic processing, play a supportive role in resolving Stroop interference.

INDIVIDUAL DIFFERENCES IN LEARNING--INTERFERENCE FACTOR.

ERIC Educational Resources Information Center

JENSEN, ARTHUR R.

AN INVESTIGATION WAS CONDUCTED (1) TO DEVISE A NUMBER OF LABORATORY MEASURES OF INDIVIDUAL DIFFERENCES IN SUSCEPTIBILITY TO INTERFERENCE EFFECTS IN LEARNING AND (2) TO DETERMINE THEIR DIMENSIONALITY IN A VARIETY OF INTERFERENCE EFFECTS. SUBJECTS WERE 530 STUDENTS IN INTRODUCTORY COURSES IN EDUCATIONAL PSYCHOLOGY AT THE UNIVERSITY OF CALIFORNIA,…

Reactivity to interpersonal stress in patients with eating disorders: A systematic review and meta-analysis of studies using an experimental paradigm.

PubMed

Monteleone, Alessio Maria; Treasure, Janet; Kan, Carol; Cardi, Valentina

2018-04-01

Reactivity to interpersonal stress in patients with eating disorders: A systematic review and meta-analysis of studies using an experimental paradigm. NEUROSCI BIOBEHAV REV XXX-XXX, 2018.- Social difficulties have been implicated in the development and maintenance of eating disorder symptoms. The aim of this work was to conduct a systematic review and meta-analysis of experimental studies testing patientsö reactivity to interpersonal stress, compared to healthy controls. Thirty-four studies were included. Meta-analyses were conducted on 16 studies and on following outcomes: attention bias and interference to threatening faces, cortisol, heart rate and negative affect before and after exposure to interpersonal stress. Patients showed heightened attention bias and interference to threatening faces. Lower heart rate after exposure to interpersonal stress and greater negative affect before and after interpersonal stress were observed in the clinical group compared to controls. Surprisingly, only a small minority of studies included measures of abnormal eating behaviour and attitudes. This seems a missed opportunity for testing the causal and maintaining role that abnormalities in interpersonal stress response play in eating disorders. Nonetheless, findings corroborate the hypothesis that patients' response to interpersonal stress differs from that of healthy controls. Copyright © 2018 Elsevier Ltd. All rights reserved.

Getting more from visual working memory: Retro-cues enhance retrieval and protect from visual interference.

PubMed

Souza, Alessandra S; Rerko, Laura; Oberauer, Klaus

2016-06-01

Visual working memory (VWM) has a limited capacity. This limitation can be mitigated by the use of focused attention: if attention is drawn to the relevant working memory content before test, performance improves (the so-called retro-cue benefit). This study tests 2 explanations of the retro-cue benefit: (a) Focused attention protects memory representations from interference by visual input at test, and (b) focusing attention enhances retrieval. Across 6 experiments using color recognition and color reproduction tasks, we varied the amount of color interference at test, and the delay between a retrieval cue (i.e., the retro-cue) and the memory test. Retro-cue benefits were larger when the memory test introduced interfering visual stimuli, showing that the retro-cue effect is in part because of protection from visual interference. However, when visual interference was held constant, retro-cue benefits were still obtained whenever the retro-cue enabled retrieval of an object from VWM but delayed response selection. Our results show that accessible information in VWM might be lost in the processes of testing memory because of visual interference and incomplete retrieval. This is not an inevitable state of affairs, though: Focused attention can be used to get the most out of VWM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Ascorbic acid interference in the measurement of serum biochemical parameters: in vivo and in vitro studies.

PubMed

Martinello, Flávia; da Silva, Edson Luiz

2006-04-01

To investigate the negative interference of ascorbic acid in serum biochemical tests in relation to the dose of vitamin C intake and to the time of blood collection. Healthy volunteers (n = 18) consumed daily doses of vitamin C (0.25-4.0 g) for 1 week and serum parameters were assayed prior to the experiment and on the eighth day of consumption. Blood samples were collected 4, 12 and 24 h after vitamin C intake. Serum levels of ascorbic acid increased significantly after vitamin C ingestion inhibiting urate and total bilirubin tests 4 and 12 h after intake (P < 0.01). A significant negative interference occurred up to 24 h after consumption of 4 g vitamin C for the urate test. In contrast, ingestion of vitamin C did not show interference in glucose, triglyceride and cholesterol tests. Addition of ascorbic acid to serum inhibited the urate test to a similar extent to that observed after vitamin C intake. However, after ingesting vitamin C, the interference for the bilirubin test was greater than that of the in vitro interference. Commonly taken doses of supplementary vitamin C interfered negatively with the serum urate test based on the Trinder method, and with bilirubin metabolism.

Mechanism of ascorbic acid interference in biochemical tests that use peroxide and peroxidase to generate chromophore.

PubMed

Martinello, Flávia; Luiz da Silva, Edson

2006-11-01

Ascorbic acid interferes negatively in peroxidase-based tests (Trinder method). However, the precise mechanism remains unclear for tests that use peroxide, a phenolic compound and 4-aminophenazone (4-AP). We determined the chemical mechanism of this interference, by examining the effects of ascorbic acid in the reaction kinetics of the production and reduction of the oxidized chromophore in urate, cholesterol, triglyceride and glucose tests. Reaction of ascorbic acid with the Trinder method constituents was also verified. Ascorbic acid interfered stoichiometrically with all tests studied. However, it had two distinct effects on the reaction rate. In the urate test, ascorbic acid decreased the chromophore formation with no change in its production kinetics. In contrast, in cholesterol, triglyceride and glucose tests, an increase in the lag phase of color development occurred. Of all the Trinder constituents, only peroxide reverted the interference. In addition, ascorbic acid did not interfere with oxidase activity nor reduce significantly the chromophore formed. Peroxide depletion was the predominant chemical mechanism of ascorbic acid interference in the Trinder method with phenolics and 4-AP. Distinctive effects of ascorbic acid on the reaction kinetics of urate, cholesterol, glucose and triglyceride might be due to the rate of peroxide production by oxidases.

D-METHIONINE REDUCES TOBRAMYCIN-INDUCED OTOTOXICITY WITHOUT ANTIMICROBIAL INTERFERENCE IN ANIMAL MODELS

PubMed Central

Fox, Daniel J.; Cooper, Morris D.; Speil, Cristian A.; Roberts, Melissa H.; Yanik, Susan C.; Meech, Robert P.; Hargrove, Tim L.; Verhulst, Steven J.; Rybak, Leonard P.; Campbell, Kathleen C. M.

2015-01-01

Background Tobramycin is a critical cystic fibrosis treatment however it causes ototoxicity. This study tested D-methionine protection from tobramycin-induced ototoxicity and potential antimicrobial interference. Methods Auditory brainstem responses (ABR) and outer hair cell (OHC) quantifications measured protection in guinea pigs treated with tobramycin and a range of D-methionine doses. In vitro antimicrobial interference studies tested inhibition and post antibiotic effect assays. In vivo antimicrobial interference studies tested normal and neutropenic E. coli murine survival and intraperitoneal lavage bacterial counts. Results D-methionine conferred significant ABR threshold shift reductions. OHC protection was less robust but significant at 20 kHz in the 420 mg/kg/day group. In vitro studies did not detect D-methionine-induced antimicrobial interference. In vivo studies did not detect D-methionine-induced interference in normal or neutropenic mice. Conclusions D-methionine protects from tobramycin-induced ototoxicity without antimicrobial interference. The study results suggest D-met as a potential otoprotectant from clinical tobramycin use in cystic fibrosis patients. PMID:26166286

d-Methionine reduces tobramycin-induced ototoxicity without antimicrobial interference in animal models.

PubMed

Fox, Daniel J; Cooper, Morris D; Speil, Cristian A; Roberts, Melissa H; Yanik, Susan C; Meech, Robert P; Hargrove, Tim L; Verhulst, Steven J; Rybak, Leonard P; Campbell, Kathleen C M

2016-07-01

Tobramycin is a critical cystic fibrosis treatment however it causes ototoxicity. This study tested d-methionine protection from tobramycin-induced ototoxicity and potential antimicrobial interference. Auditory brainstem responses (ABRs) and outer hair cell (OHC) quantifications measured protection in guinea pigs treated with tobramycin and a range of d-methionine doses. In vitro antimicrobial interference studies tested inhibition and post antibiotic effect assays. In vivo antimicrobial interference studies tested normal and neutropenic Escherichia coli murine survival and intraperitoneal lavage bacterial counts. d-Methionine conferred significant ABR threshold shift reductions. OHC protection was less robust but significant at 20kHz in the 420mg/kg/day group. In vitro studies did not detect d-methionine-induced antimicrobial interference. In vivo studies did not detect d-methionine-induced interference in normal or neutropenic mice. d-Methionine protects from tobramycin-induced ototoxicity without antimicrobial interference. The study results suggest d-met as a potential otoprotectant from clinical tobramycin use in cystic fibrosis patients. Published by Elsevier B.V.

The effect of canard leading edge sweep and dihedral angle on the longitudinal and lateral aerodynamic characteristic of a close-coupled canard-wing configuration

NASA Technical Reports Server (NTRS)

Gloss, B. B.

1974-01-01

A generalized wind-tunnel model, with canard and wing planforms typical of highly maneuverable aircraft, was tested in the Langley high-speed 7- by 10-foot tunnel at a Mach number of 0.30. The test was conducted in order to determine the effects of canard sweep and canard dihedral on canard-wing interference at high angles of attack. In general, the effect of canard sweep on lift is small up to an angle of attack of 16 deg. However, for angles of attack greater than 16 deg, an increase in the canard sweep results in an increase in lift developed by the canard when the canard is above or in the wing chord plane. This increased lift results in a lift increase for the total configuration for the canard above the wing chord plane. For the canard in the wing chord plane, the increased canard lift is partially lost by increased interference on the wing.

Chlorinated Cyanurates: Method Interferences and Application Implications

EPA Science Inventory

Experiments were conducted to investigate method interferences, residual stability, regulated DBP formation, and a water chemistry model associated with the use of Dichlor & Trichlor in drinking water.

40 CFR Table B-3 to Subpart B of... - Interferent Test Concentration, Parts per Million

Code of Federal Regulations, 2012 CFR

2012-07-01

... per Million B Table B-3 to Subpart B of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION..., Subpt. B, Table B-3 Table B-3 to Subpart B of Part 53—Interferent Test Concentration, Parts per Million Table B-3 to Subpart B of Part 53—Interferent Test Concentration,1 Parts per Million Pollutant Analyzer...

40 CFR Table B-3 to Subpart B of... - Interferent Test Concentration,1 Parts per Million

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Interferent Test Concentration,1 Parts per Million B Table B-3 to Subpart B of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION..., Subpt. B, Table B-3 Table B-3 to Subpart B of Part 53—Interferent Test Concentration,1 Parts per Million...

Design and development of multipurpose Kundt’s tube as physics learning media

NASA Astrophysics Data System (ADS)

Nursulistiyo, E.

2018-03-01

Research had been conducted to develop Multipurpose Kundt's tube as a physics learning media. Research background was the absence of sound waves visualization to improve the understanding of learners. The purposes of this research were to develop Multipurpose Kundt’s tube as physics learning media and to test its feasibility. The developed tool was tested to find the speed of sound in the air, showing the double slit interference phenomenon of the sound, and show the temperature changes in the cold and heat reservoirs in the thermoacoustic process. The development step that had been used was Preliminary Study, Development, Field Test, and Dissemination or known as PDFD Model. On the implementation, the dissemination process was not done. The test was done by the experts, peers, and college students to find out the media feasibility level. The speed of sound in the air which was measured using Multipurpose Kundt’s tube obtained v ± Δv = 263 ± 24 m/s with the closeness value of 76.63% closer to the theoretical value. Also, it was founded a calibration factor of 1.32. The tool was able to show sound waves on the open-end tube. The value of the distance between minimum and maximum interferences between the experimental results compared to theory was almost the same, so it was concluded that the phenomenon of double-slit interference of the sound could be shown by the tool. The thermoacoustic phenomenon could be observed and gave maximum temperature 31.4°C in the hot reservoir, and minimum temperature 24°C in the cold reservoir at the frequency of 119 Hz. Temperature differences obtained 7.4°C. The result of the feasibility test obtained the average result of 88.23 in a “Very Good” category.

Assessment and control of spacecraft electromagnetic interference

NASA Technical Reports Server (NTRS)

1972-01-01

Design criteria are presented to provide guidance in assessing electromagnetic interference from onboard sources and establishing requisite control in spacecraft design, development, and testing. A comprehensive state-of-the-art review is given which covers flight experience, sources and transmission of electromagnetic interference, susceptible equipment, design procedure, control techniques, and test methods.

Phase 2 and 3 wind tunnel tests of the J-97 powered, external augmentor V/STOL model. [conducted in Ames 40- by 80-foot wind tunnel

NASA Technical Reports Server (NTRS)

Garland, D. B.

1980-01-01

Modifications were made to the model to improve longitudinal acceleration capability during transition from hovering to wing borne flight. A rearward deflection of the fuselage augmentor thrust vector is shown to be beneficial in this regard. Other agmentor modifications were tested, notably the removal of both endplates, which improved acceleration performance at the higher transition speeds. The model tests again demonstrated minimal interference of the fuselage augmentor on aerodynamic lift. A flapped canard surface also shows negligible influence on the performance of the wing and of the fuselage augmentor.

Electroless shielding of plastic electronic enclosures

NASA Astrophysics Data System (ADS)

Thompson, D.

1985-12-01

The containment or exclusion of radio frequency interference (RFI) via metallized plastic enclosures and the electroless plating as a solution are examined. The electroless coating and process, shielding principles and test data, shielding design requirements, and shielding advantages and limitations are reviewed. It is found that electroless shielding provides high shielding effectiveness to plastic substrates. After application of a conductive metallic coating by electroless plating, various plastics have passed the ASTM adhesion test after thermal cycle and severe environmental testing. Electroless shielding provides a lightweight, totally metallized housing to EMI/RFI shielding. Various compositions of electroless deposits are found to optimize electroless shielding cost/benefit ratio.

Pharmacological interference with 123I-metaiodobenzylguanidine: a limitation to developing cardiac innervation imaging in clinical practice?

PubMed

Stefanelli, A; Treglia, G; Bruno, I; Rufini, V; Giordano, A

2013-05-01

(123)I-metaiodo-benzylguanidine (MIBG) scintigraphy is considered a valid imaging test to evaluate the cardiac sympathetic nervous system. However, scientific literature showed that some drugs are able to or are expected to interfere with MIBG uptake. Thirty years after introduction of the method and over 15 years since the appearance of the first document on pharmacological interference with MIBG, an update on this issue has become necessary. The aims of this review paper are: (1) to identify the pharmacological basis of interference of a variety of substances with MIBG uptake; and (2) to update the list of drugs that definitely interfere with MIBG on the grounds of evidence in the literature. A MEDLINE search was conducted. Scientific studies, case report and review articles were collected. Papers published demonstrating drugs interfering with MIBG uptake were evaluated. Drugs may interact with MIBG uptake by 5 mechanism: (1) type-1 uptake inhibition; (2) inhibition of active transport to vesicles; (3) competition in transport to vesicles; (4) depletion of neurosecretory vesicle content; (5) calcium-mediated mechanism. We find that drugs like cocaine, antidepressants, some antipsychotic, tramadol, labetalol, sympatho-mimetics, reserpine and some calcium antagonists (as diltiazem, verapamil and nifedipine) do interfere with MIBG uptake. On the other hand, we find that controversial data are available on scientific literature regarding digoxin and amiodarone. A compiled statement of MIBG interfering medicines is now recommended to help nuclear medicine physicians in clinical practice to avoid potential pitfalls and improve the efficacy of (123)I-MIBG scintigraphy as a diagnostic tool.

Capabilities of wind tunnels with two-adaptive walls to minimize boundary interference in 3-D model testing

NASA Technical Reports Server (NTRS)

Rebstock, Rainer; Lee, Edwin E., Jr.

1989-01-01

An initial wind tunnel test was made to validate a new wall adaptation method for 3-D models in test sections with two adaptive walls. First part of the adaptation strategy is an on-line assessment of wall interference at the model position. The wall induced blockage was very small at all test conditions. Lift interference occurred at higher angles of attack with the walls set aerodynamically straight. The adaptation of the top and bottom tunnel walls is aimed at achieving a correctable flow condition. The blockage was virtually zero throughout the wing planform after the wall adjustment. The lift curve measured with the walls adapted agreed very well with interference free data for Mach 0.7, regardless of the vertical position of the wing in the test section. The 2-D wall adaptation can significantly improve the correctability of 3-D model data. Nevertheless, residual spanwise variations of wall interference are inevitable.

Space shuttle solid rocket booster sting interference wind tunnel test analysis

NASA Technical Reports Server (NTRS)

Conine, B.; Boyle, W.

1981-01-01

Wind tunnel test results from shuttle solid rocket booster (SRB) sting interference tests were evaluated, yielding the general influence of the sting on the normal force and pitching moment coefficients and the side force and yawing moment coefficients. The procedures developed to determine the sting interference, the development of the corrected aerodynamic data, and the development of a new SRB aerodynamic mathematical model are documented.

Poor Stroop performances in 15-year-old dyslexic teenagers.

PubMed

Kapoula, Zoï; Lê, Thanh-Thuan; Bonnet, Audrey; Bourtoire, Pauline; Demule, Emilie; Fauvel, Caroline; Quilicci, Catherine; Yang, Qing

2010-06-01

The Stroop test enables interference between color naming and reading to be studied. Protopapas et al. (2007) reported more errors in an interference task and longer reaction times in 12.5-year-old dyslexics; also more Stroop interference with lower reading skills. The present study uses a version of the Stroop with four color cards and aims to test interference and flexibility in older dyslexic teenagers. The four cards are: color naming, reading, interference and flexibility. In the latter, subjects have to name the color of the word inhibiting reading except when the word is inside a box. This flexibility task enables the testing of the capacity for cognitive switching between tasks. Ten dyslexics (15.1 +/- 0.7 years old) and fourteen controls (14.3 +/- 1.6 years old) participated in the study. All performed the color naming, the reading, the interference and the flexibility tasks in the same order. Subsequently, they performed a sequence of 60 saccades left-right followed by the interference task. Generally, dyslexic teenagers behaved similarly to non-dyslexics as they showed fewer errors in reading and color than in the interference and flexibility tasks. However, they made more errors and needed more time to accomplish each task than non-dyslexics. The results suggest that the inhibitory and attention processes required by the Stroop test are dysfunctioning even in older dyslexics. In contrast, the study shows no evidence for particular difficulty in the flexibility task, which would constitute an argument against problems with mental switching. Following the execution of saccades, errors in the interference test were significantly reduced for dyslexics, while the time was reduced for both groups. The effects are attributed to visual attention training via saccades.

Results of the recent precipitation static flight test program on the Navy P-3B antisubmarine aircraft

NASA Technical Reports Server (NTRS)

Whitaker, Mike

1991-01-01

Severe precipitation static problems affecting the communication equipment onboard the P-3B aircraft were recently studied. The study was conducted after precipitation static created potential safety-of-flight problems on Naval Reserve aircraft. A specially designed flight test program was conducted in order to measure, record, analyze, and characterize potential precipitation static problem areas. The test program successfully characterized the precipitation static interference problems while the P-3B was flown in moderate to extreme precipitation conditions. Data up to 400 MHz were collected on the effects of engine charging, precipitation static, and extreme cross fields. These data were collected using a computer controlled acquisition system consisting of a signal generator, RF spectrum and audio analyzers, data recorders, and instrumented static dischargers. The test program is outlined and the computer controlled data acquisition system is described in detail which was used during flight and ground testing. The correlation of test results is also discussed which were recorded during the flight test program and those measured during ground testing.

Critical assessment of precracked specimen configuration and experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate

NASA Technical Reports Server (NTRS)

Domack, M. S.

1985-01-01

A research program was conducted to critically assess the effects of precracked specimen configuration, stress intensity solutions, compliance relationships and other experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate. Modified compact and double beam wedge-loaded specimens were tested and analyzed to determine the threshold stress intensity factor and stress corrosion crack growth rate. Stress intensity solutions and experimentally determined compliance relationships were developed and compared with other solutions available in the literature. Crack growth data suggests that more effective crack length measurement techniques are necessary to better characterize stress corrosion crack growth. Final load determined by specimen reloading and by compliance did not correlate well, and was considered a major source of interlaboratory variability. Test duration must be determined systematically, accounting for crack length measurement resolution, time for crack arrest, and experimental interferences. This work was conducted as part of a round robin program sponsored by ASTM committees G1.06 and E24.04 to develop a standard test method for stress corrosion testing using precracked specimens.

Wind tunnel wall interference (January 1980 - May 1988): A selected, annotated bibliography

NASA Technical Reports Server (NTRS)

Tuttle, Marie H.; Cole, Karen L.

1988-01-01

This selected bibliography lists 423 entries on the subject of wall interference during testing in wind tunnels. It is the third in a series of bibliographies on the subject. The first, NASA TM-87639, August 1986, is concerned with the reduction of wall interference by the use of adaptive walls. The second, NASA TP-89066, December 1986, is on wall interference in V/STOL and high lift testing. This, the third in the series, covers the wall interference literature published during the period January 1980 through May 1988, generally excluding those topics covered in the first two parts.

40 CFR Table B-3 to Subpart B of... - Interferent Test Concentration, 1 Parts per Million

Code of Federal Regulations, 2013 CFR

2013-07-01

... Nitric oxide Carbon dioxide Ethylene Ozone Mxy-lene Water vapor Carbon monoxide Methane Ethane... 4 0.14 750 3 20,000 50 SO2 Gas chromatography 0.1 4 0.14 750 3 20,000 50 SO2 Spectrophotometric-wet... 0.5 3 20,000 SO2 Conductivity 0.2 0.1 4 0.14 0.5 750 SO2 Spectrophotometric-gas phase, including...

Event-based proactive interference in rhesus monkeys.

PubMed

Devkar, Deepna T; Wright, Anthony A

2016-10-01

Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

A model of work-family conflict and well-being among Malaysian working women.

PubMed

Aazami, Sanaz; Akmal, Syaqirah; Shamsuddin, Khadijah

2015-01-01

Work and family are the two most important domains in a person's life. Lack of balance between work and family can lead to adverse consequences such as psychological distress; however, the effect of work-family conflict on psychological distress might be mediated by job and family dissatisfaction. This study examines a model of the four dimensions of work-family conflict and their consequences on psychological distress. In particular, we test whether job and family satisfaction mediate the effect of the four dimensions of work-family conflict on psychological distress. This cross-sectional study was conducted among 567 Malaysian women who are working in the public services. Structural Equation Modeling confirmed the mediating role of family satisfaction in the effect of strain-based work interference into family and time-based family interference into work on psychological distress. In addition, our results revealed a significant path that links job to family satisfaction. Moreover, time-based work interference into family and strain-based family interference into work significantly and negatively affect job satisfaction, which in turn influence family satisfaction and eventually affect psychological distress. The results of our study show that organizations need to develop and adapt family friendly policies to mitigate level of employees' work-family conflict.

Subsonic sting interference on the aerodynamic characteristics of a family of slanted-base ogive-cylinders

NASA Technical Reports Server (NTRS)

Britcher, Colin P.; Alcorn, Charles W.; Kilgore, W. Allen

1990-01-01

Support interference free drag, lift, and pitching moment measurements on a range of slanted base ogive cylinders were made using the NASA Langley 13 inch magnetic suspension and balance system. Typical test Mach numbers were in the range 0.04 to 0.2. Drag results are shown to be in broad agreement with previous tests with this configuration. Measurements were repeated with a dummy sting support installed in the wind tunnel. Significant support interferences were found at all test conditions and are quantified. Further comparison is made between interference free base pressures, obtained using remote telemetry, and sting cavity pressures.

Results of heat transfer tests of an 0.0175-scale space shuttle vehicle model 22 OTS in the NASA-Ames 3.5-foot hypersonic wind tunnel (IH3), volume 4

NASA Technical Reports Server (NTRS)

Foster, T. F.; Lockman, W. K.

1975-01-01

Heat-transfer data for the 0.0175-scale Space Shuttle Vehicle 3 are presented. Interference heating effects were investigated by a model build-up technique of Orbiter alone, tank alone, second, and first stage configurations. The test program was conducted in the NASA-Ames 3.5-Foot Hypersonic Wind Tunnel at Mach 5.3 for nominal free-stream Reynolds number per foot values of 1.5 x 1,000,000 and 5.0 x 1,000,000.

Stroop Color-Word Interference Test: Normative data for Spanish-speaking pediatric population.

PubMed

Rivera, D; Morlett-Paredes, A; Peñalver Guia, A I; Irías Escher, M J; Soto-Añari, M; Aguayo Arelis, A; Rute-Pérez, S; Rodríguez-Lorenzana, A; Rodríguez-Agudelo, Y; Albaladejo-Blázquez, N; García de la Cadena, C; Ibáñez-Alfonso, J A; Rodriguez-Irizarry, W; García-Guerrero, C E; Delgado-Mejía, I D; Padilla-López, A; Vergara-Moragues, E; Barrios Nevado, M D; Saracostti Schwartzman, M; Arango-Lasprilla, J C

2017-01-01

To generate normative data for the Stroop Word-Color Interference test in Spanish-speaking pediatric populations. The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the Stroop Word-Color Interference test as part of a larger neuropsychological battery. The Stroop Word, Stroop Color, Stroop Word-Color, and Stroop Interference scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. The final multiple linear regression models showed main effects for age on all scores, except on Stroop Interference for Guatemala, such that scores increased linearly as a function of age. Age2 affected Stroop Word scores for all countries, Stroop Color scores for Ecuador, Mexico, Peru, and Spain; Stroop Word-Color scores for Ecuador, Mexico, and Paraguay; and Stroop Interference scores for Cuba, Guatemala, and Spain. MLPE affected Stroop Word scores for Chile, Mexico, and Puerto Rico; Stroop Color scores for Mexico, Puerto Rico, and Spain; Stroop Word-Color scores for Ecuador, Guatemala, Mexico, Puerto Rico and Spain; and Stroop-Interference scores for Ecuador, Mexico, and Spain. Sex affected Stroop Word scores for Spain, Stroop Color scores for Mexico, and Stroop Interference for Honduras. This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate approach to interpret the Stroop Word-Color Interference test in pediatric populations.

Proactive Interference in Short-Term Recognition and Recall Memory

ERIC Educational Resources Information Center

Dillon, Richard F.; Petrusic, William M.

1972-01-01

Purpose of study was to (a) compare the rate of increase of proactive interference over the first few trials under recall and recognition memory test conditions, (2) determine the effects of two types of distractors on short-term recognition, and (3) test memory after proactive interference had reached a stable level under each of three test…

An Environmental Sentinel Biomonitor System for Drinking Water Protection

DTIC Science & Technology

2008-12-01

threat chemicals. Potential interferences include chemicals commonly used for drinking water disinfection (chlorine and chloramine ), byproducts of...range. Of the potential interferences tested, the ECIS test was affected only by the disinfectants chlorine and chloramine ; chlorine is typically...Industrial and Potential Interfering Chemicals Used to Evaluate ESB System Toxicity Sensors TICs Potential Interferences Acrylonitrile Chloramine

Interference effects on vibration-mediated tunneling through interacting degenerate molecular states.

PubMed

Zhong, X; Cao, J C

2009-07-22

We study the combined effects of quantum electronic interference and Coulomb interaction on electron transport through near-degenerate molecular states with strong electron-vibration interaction. It is found that quantum electronic interference strongly affects the current and its noise properties. In particular, destructive interference induces pronounced negative differential conductances (NDCs) accompanying the vibrational excited states, and such NDC characters are not related to asymmetric tunnel coupling and are robust to the damping of a thermal bath. In a certain transport regime, the non-equilibrium vibration distribution even shows a peculiar sub-Poissonian behavior, which is enhanced by quantum electronic interference.

Capabilities, Design, Construction and Commissioning of New Vibration, Acoustic, and Electromagnetic Capabilities Added to the World's Largest Thermal Vacuum Chamber at NASA's Space Power Facility

NASA Technical Reports Server (NTRS)

Motil, Susan M.; Ludwiczak, Damian R.; Carek, Gerald A.; Sorge, Richard N.; Free, James M.; Cikanek, Harry A., III

2011-01-01

NASA s human space exploration plans developed under the Exploration System Architecture Studies in 2005 included a Crew Exploration Vehicle launched on an Ares I launch vehicle. The mass of the Crew Exploration Vehicle and trajectory of the Ares I coupled with the need to be able to abort across a large percentage of the trajectory generated unprecedented testing requirements. A future lunar lander added to projected test requirements. In 2006, the basic test plan for Orion was developed. It included several types of environment tests typical of spacecraft development programs. These included thermal-vacuum, electromagnetic interference, mechanical vibration, and acoustic tests. Because of the size of the vehicle and unprecedented acoustics, NASA conducted an extensive assessment of options for testing, and as result, chose to augment the Space Power Facility at NASA Plum Brook Station, of the John H. Glenn Research Center to provide the needed test capabilities. The augmentation included designing and building the World s highest mass capable vibration table, the highest power large acoustic chamber, and adaptation of the existing World s largest thermal vacuum chamber as a reverberant electromagnetic interference test chamber. These augmentations were accomplished from 2007 through early 2011. Acceptance testing began in Spring 2011 and will be completed in the Fall of 2011. This paper provides an overview of the capabilities, design, construction and acceptance of this extraordinary facility.

The effect of wind tunnel wall interference on the performance of a fan-in-wing VTOL model

NASA Technical Reports Server (NTRS)

Heyson, H. H.

1974-01-01

A fan-in-wing model with a 1.07-meter span was tested in seven different test sections with cross-sectional areas ranging from 2.2 sq meters to 265 sq meters. The data from the different test sections are compared both with and without correction for wall interference. The results demonstrate that extreme care must be used in interpreting uncorrected VTOL data since the wall interference may be so large as to invalidate even trends in the data. The wall interference is particularly large at the tail, a result which is in agreement with recently published comparisons of flight and large scale wind tunnel data for a propeller-driven deflected-slipstream configuration. The data verify the wall-interference theory even under conditions of extreme interference. A method yields reasonable estimates for the onset of Rae's minimum-speed limit. The rules for choosing model sizes to produce negligible wall effects are considerably in error and permit the use of excessively large models.

Inductive interference in rapid transit signaling systems. volume 2. suggested test procedures.

DOT National Transportation Integrated Search

1987-03-31

These suggested test procedures have been prepared in order to develop standard methods of analysis and testing to quantify and resolve issues of electromagnetic compatibility in rail transit operations. Electromagnetic interference, generated by rai...

Qualification of Electrical Ground Support Equipment for New Space Programs

NASA Technical Reports Server (NTRS)

SotoToro, Felix A.; Vu, Bruce T.; Hamilton, Mark S.

2011-01-01

With the Space Shuttle program coming to an end, the National Aeronautics and Space Administration (NASA) is moving to a new space flight program that will allow expeditions beyond low earth orbit. The space vehicles required to comply with these missions will be carrying heavy payloads. This implies that the Earth departure stage capabilities must be of higher magnitudes, given the current propulsion technology. The engineering design of the new flight hardware comes with some structural, thermal, propulsion and other subsystems' challenges. Meanwhile, the necessary ground support equipment (GSE) used to test, validate, verify and process the flight hardware must withstand the new program specifications. This paper intends to provide the qualification considerations during implementation of new electrical GSE for space programs. A team of engineers was formed to embark on this task, and facilitate the logistics process and ensure that the electrical, mechanical and fluids subsystems conduct the proper level of testing. Ultimately, each subsystem must certify that each piece of ground support equipment used in the field is capable of withstanding the strenuous vibration, acoustics, environmental, thermal and Electromagnetic Interference (EMf) levels experienced during pre-launch, launch and post-launch activities. The benefits of capturing and sharing these findings will provide technical, cost savings and schedule impacts infon11ation to both the technical and management community. Keywords: Qualification; Testing; Ground Support Equipment; Electromagnetic Interference Testing; Vibration Testing; Acoustic Testing; Power Spectral Density.

Sodium interference in the determination of urinary aldosterone.

PubMed

Aldea, Marta Lucía; Barallat, Jaume; Martín, María Amparo; Rosas, Irene; Pastor, María Cruz; Granada, María Luisa

2016-02-01

Primary hyperaldosteronism (PHA) is one of the most common endocrine forms of secondary hypertension. Among the most used confirmatory tests for PHA is urinary aldosterone determination after oral sodium loading test. The primary aim of our study was to investigate if sodium concentrations interfere with urinary aldosterone in an automated competitive immunoassay (Liaison®) as well as to verify the manufacturer's specifications. 24-hr urine samples were collected and stored frozen until assayed. Two pools at low and high aldosterone concentrations were prepared. Verification of performance for precision was tested according to Clinical and Laboratory Standards Institute (CLSI) document EP15-A2 and interference with increasing concentrations of NaCl according to CLSI EP7-A2. The assay met the quality specifications according to optimal biological variation. Our results show that sodium concentrations up to 200mmol/L do not interfere on urinary aldosterone quantification, but sodium concentrations above 486mmol/L negatively interfere with the test. The Liaison® automated method is useful for aldosterone determination in the PHA confirmatory test, but interferences with NaCl may occur. It is therefore recommended to determine urinary NaCl before measuring urinary aldosterone to avoid falsely low results. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Evaluation of Three Different Processing Techniques in the Fabrication of Complete Dentures

PubMed Central

Chintalacheruvu, Vamsi Krishna; Balraj, Rajasekaran Uttukuli; Putchala, Lavanya Sireesha; Pachalla, Sreelekha

2017-01-01

Aims and Objectives: The objective of the present study is to compare the effectiveness of three different processing techniques and to find out the accuracy of processing techniques through number of occlusal interferences and increase in vertical dimension after denture processing. Materials and Methods: A cross-sectional study was conducted on a sample of 18 patients indicated for complete denture fabrication was selected for the study and they were divided into three subgroups. Three processing techniques, compression molding and injection molding using prepolymerized resin and unpolymerized resin, were used to fabricate dentures for each of the groups. After processing, laboratory-remounted dentures were evaluated for number of occlusal interferences in centric and eccentric relations and change in vertical dimension through vertical pin rise in articulator. Data were analyzed using statistical test ANOVA and SPSS software version 19.0 by IBM was used. Results: Data obtained from three groups were subjected to one-way ANOVA test. After ANOVA test, results with significant variations were subjected to post hoc test. Number of occlusal interferences with compression molding technique was reported to be more in both centric and eccentric positions as compared to the two injection molding techniques with statistical significance in centric, protrusive, right lateral nonworking, and left lateral working positions (P < 0.05). Mean vertical pin rise (0.52 mm) was reported to more in compression molding technique as compared to injection molding techniques, which is statistically significant (P < 0.001). Conclusions: Within the limitations of this study, injection molding techniques exhibited less processing errors as compared to compression molding technique with statistical significance. There was no statistically significant difference in processing errors reported within two injection molding systems. PMID:28713763

Evaluation of Three Different Processing Techniques in the Fabrication of Complete Dentures.

PubMed

Chintalacheruvu, Vamsi Krishna; Balraj, Rajasekaran Uttukuli; Putchala, Lavanya Sireesha; Pachalla, Sreelekha

2017-06-01

The objective of the present study is to compare the effectiveness of three different processing techniques and to find out the accuracy of processing techniques through number of occlusal interferences and increase in vertical dimension after denture processing. A cross-sectional study was conducted on a sample of 18 patients indicated for complete denture fabrication was selected for the study and they were divided into three subgroups. Three processing techniques, compression molding and injection molding using prepolymerized resin and unpolymerized resin, were used to fabricate dentures for each of the groups. After processing, laboratory-remounted dentures were evaluated for number of occlusal interferences in centric and eccentric relations and change in vertical dimension through vertical pin rise in articulator. Data were analyzed using statistical test ANOVA and SPSS software version 19.0 by IBM was used. Data obtained from three groups were subjected to one-way ANOVA test. After ANOVA test, results with significant variations were subjected to post hoc test. Number of occlusal interferences with compression molding technique was reported to be more in both centric and eccentric positions as compared to the two injection molding techniques with statistical significance in centric, protrusive, right lateral nonworking, and left lateral working positions ( P < 0.05). Mean vertical pin rise (0.52 mm) was reported to more in compression molding technique as compared to injection molding techniques, which is statistically significant ( P < 0.001). Within the limitations of this study, injection molding techniques exhibited less processing errors as compared to compression molding technique with statistical significance. There was no statistically significant difference in processing errors reported within two injection molding systems.

Material-specific retroactive interference effects of the Wechsler Adult Intelligence Scale-Fourth Edition on the Wechsler Memory Scale-Fourth Edition in a nonclinical sample.

PubMed

Ingram, Nicolette S; Diakoumakos, Jessica V; Sinclair, Erin R; Crowe, Simon F

2016-01-01

This study investigated proactive and retroactive interference effects between the Wechsler Memory Scale-Fourth Edition (WMS-IV) using the flexible approach, and the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). One hundred and eighty nonclinical participants were assigned to a four (visual interference, verbal interference, visual and verbal interference, vs. no interference) by two (retroactive vs. proactive) between-subjects design. The administration order of the tests was counterbalanced (i.e., administration of the WAIS-IV prior to the WMS-IV, and the WAIS-IV administered during the delay interval of the WMS-IV). The WAIS-IV produced significant retroactive interference effects on the WMS-IV; however, no proactive interference effect was observed. The retroactive interference effect was dependent on material specificity. The results indicate that material presented within the delay of the WMS-IV can have a significant effect on subsequent delayed recall. Clinicians should carefully consider the effects associated with carry-over effects of these tests when using them in combination.

Color-Object Interference: Further Tests of an Executive Control Account

ERIC Educational Resources Information Center

La Heij, Wido; Boelens, Harrie

2011-01-01

Young children are slower in naming the color of a meaningful picture than in naming the color of an abstract form (Stroop-like color-object interference). The current experiments tested an executive control account of this phenomenon. First, color-object interference was observed in 6- and 8-year-olds but not in 12- and 16-year-olds (Experiment…

Effect of hemoglobin- and Perflubron-based oxygen carriers on common clinical laboratory tests.

PubMed

Ma, Z; Monk, T G; Goodnough, L T; McClellan, A; Gawryl, M; Clark, T; Moreira, P; Keipert, P E; Scott, M G

1997-09-01

Polymerized hemoglobin solutions (Hb-based oxygen carriers; HBOCs) and a second-generation perfluorocarbon (PFC) emulsion (Perflubron) are in clinical trials as temporary oxygen carriers ("blood substitutes"). Plasma and serum samples from patients receiving HBOCs look markedly red, whereas those from patients receiving PFC appear to be lipemic. Because hemolysis and lipemia are well-known interferents in many assays, we examined the effects of these substances on clinical chemistry, immunoassay, therapeutic drug, and coagulation tests. HBOC concentrations up to 50 g/L caused essentially no interference for Na, K, Cl, urea, total CO2, P, uric acid, Mg, creatinine, and glucose values determined by the Hitachi 747 or Vitros 750 analyzers (or both) or for immunoassays of lidocaine, N-acetylprocainamide, procainamide, digoxin, phenytoin, quinidine, or theophylline performed on the Abbott AxSym or TDx. Gentamycin and vancomycin assays on the AxSym exhibited a significant positive and negative interference, respectively. Immunoassays for TSH on the Abbott IMx and for troponin I on the Dade Stratus were unaffected by HBOC at this concentration. Tests for total protein, albumin, LDH, AST, ALT, GGT, amylase, lipase, and cholesterol were significantly affected to various extents at different HBOC concentrations on the Hitachi 747 and Vitros 750. The CK-MB assay on the Stratus exhibited a negative interference at 5 g/L HBOC. HBOC interference in coagulation tests was method-dependent-fibrometer-based methods on the BBL Fibro System were free from interference, but optical-based methods on the MLA 1000C exhibited interferences at 20 g/L HBOC. A 1:20 dilution of the PFC-based oxygen carrier (600 g/L) caused no interference on any of these chemistry or immunoassay tests except for amylase and ammonia on the Vitros 750 and plasma iron on the Hitachi 747.

Land mobile communications in Ku-band - Results of a test campaign on Eutelsat I-F1

NASA Astrophysics Data System (ADS)

Dutronc, J.; Colcy, J. N.

1990-02-01

This paper discusses the results of technical tests on land mobile communications conducted in June and July 1989 in Europe using a Eutelsat satellite. The land-mobile communication system under test was that already operated by QUALCOMM in the U.S. under the registered name OmniTRACS. The aim of the field trial was to evaluate the technical characteristics of the system and test its performance in different operating conditions. The results establish the relationship between transmission performance (i.e. essentially the required number of transmission attempts in order to get a message through the communication channel), and the environment of the land mobile, the satellite transponder's mode of operations and the interference conditions.

Validation of Blockage Interference Corrections in the National Transonic Facility

NASA Technical Reports Server (NTRS)

Walker, Eric L.

2007-01-01

A validation test has recently been constructed for wall interference methods as applied to the National Transonic Facility (NTF). The goal of this study was to begin to address the uncertainty of wall-induced-blockage interference corrections, which will make it possible to address the overall quality of data generated by the facility. The validation test itself is not specific to any particular modeling. For this present effort, the Transonic Wall Interference Correction System (TWICS) as implemented at the NTF is the mathematical model being tested. TWICS uses linear, potential boundary conditions that must first be calibrated. These boundary conditions include three different classical, linear. homogeneous forms that have been historically used to approximate the physical behavior of longitudinally slotted test section walls. Results of the application of the calibrated wall boundary conditions are discussed in the context of the validation test.

Changing room cues reduces the effects of proactive interference in Clark's Nutcrackers, Nucifraga columbiana.

PubMed

Lewis, Jody L; Kamil, Alan C; Webbink, Kate E

2013-04-01

To determine what factors are important for minimizing interference effects in spatial memory, Clark's Nutcrackers, Nucifraga columbiana were tested for their spatial memory for two serial lists of locations per day. In this experiment two unique landmark sets were either different between List 1 and List 2 or the same. We found that Nutcrackers were most susceptible to interference when the landmark sets were the same. This study suggests that repeatedly testing animal memory in the same room, with the same cues, can hamper recall due to interference.

Prevalence of executive dysfunction in cocaine, heroin and alcohol users enrolled in therapeutic communities.

PubMed

Fernández-Serrano, María José; Pérez-García, Miguel; Perales, José C; Verdejo-García, Antonio

2010-01-10

Many studies have observed relevant executive alterations in polysubstance users but no data have been generated in terms of prevalence of these alterations. Studies of the prevalence of neuropsychological impairment can be useful in the design and implementations of interventional programs for substance abusers. The present study was conducted to estimate the prevalence of neuropsychological impairment in different components of executive functions in polysubstance users enrolled in therapeutic communities. Moreover, we estimated the effect size of the differences in the executive performance between polysubstance users and non substance users in order to know which neuropsychological tasks can be useful to detect alterations in the executive functions. Study results showed a high prevalence of executive function impairment in polysubstance users. Working memory was the component with the highest impairment proportion, followed by fluency, shifting, planning, multi-tasking and interference. Comparisons between user groups showed very similar executive impairment prevalence for all the analyzed executive components. The best discriminating task between users and controls was Arithmetic (Wechsler Adult Intelligence Scale, WAIS-III). Moreover FAS and Ruff Figural Fluency Test was discriminating for fluency, Category Test for shifting, Stroop Colour-Word Interference Test for interference, Zoo Map (Behavioural Assessment of the Dysexecutive Syndrome, BADS) for planning and Six Elements (BADS) for multi-tasking. The existence of significant prevalence of executive impairment in polysubstance users reveals the need to redirect the actuation policies in the field of drug-dependency towards the creation of treatments addressed at the executive deficits of the participants, which in turn would facilitate the individuals' compliance and final rehabilitation.

Long-term interference at the semantic level: Evidence from blocked-cyclic picture matching.

PubMed

Wei, Tao; Schnur, Tatiana T

2016-01-01

Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn) from an array of unrelated pictures. Across trials, probes were either semantically related or unrelated. To test the locus of interference, we presented probes as either words or pictures. If semantic interference occurs at the stage common to both tasks, that is, access to semantic representations, then interference should occur in both probe presentation modalities. Results showed clear semantic interference effects independent of presentation modality and lexical frequency, confirming a semantic locus of interference in comprehension. To test the mechanism of interference, we repeated trials across 4 presentation cycles and manipulated the number of unrelated intervening trials (zero vs. two). We found that semantic interference was additive across cycles and survived 2 intervening trials, demonstrating interference to be long-lasting as opposed to short-lived. However, interference was smaller with zero versus 2 intervening trials, which we interpret to suggest that short-lived facilitation counteracted the long-lived interference. We propose that retrieving meanings associated with words/pictures from the same semantic category yields both interference due to long-lasting changes in connection strength between semantic representations (i.e., incremental learning) and facilitation caused by short-lived residual activation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Widespread Nanoparticle-Assay Interference: Implications for Nanotoxicity Testing

PubMed Central

Ong, Kimberly J.; MacCormack, Tyson J.; Clark, Rhett J.; Ede, James D.; Ortega, Van A.; Felix, Lindsey C.; Dang, Michael K. M.; Ma, Guibin; Fenniri, Hicham; Veinot, Jonathan G. C.; Goss, Greg G.

2014-01-01

The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1) nanoparticle intrinsic fluorescence/absorbance, 2) interactions between nanoparticles and assay components, and 3) the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments. PMID:24618833

Adaptive wall research with two- and three-dimensional models in low speed and transonic tunnels

NASA Technical Reports Server (NTRS)

Lewis, M. C.; Neal, G.; Goodyer, M. J.

1988-01-01

This paper summarises recent research at the University of Southampton into adaptive wall technology and outlines the direction of current efforts. The work is aimed at developing techniques for use in test sections where the top and bottom walls may be adjusted in single curvature. Wall streamlining eliminates, as far as experimentally possible, the top and bottom wall interference in low speed and transonic aerofoil testing. A streamlining technique has been developed for low speeds which allows the testing of swept wing panels in low interference environments. At higher speeds, a comparison of several two-dimensional transonic streamlining algorithms has been made and a technique for streamlining with a choked test section has also been developed. Three-dimensional work has mainly concentrated on tests of sidewall mounted half-wings and the development of the software packages required to assess interference and to adjust the flexible walls. It has been demonstrated that two-dimensional wall adaptation can significantly modify the level of wall interference around relatively large three-dimensional models. The residual interferences are small and are probably amenable to standard post-test correction methods. Tests on a calibrated wing-body model are planned in the near future to further validate the proposed streamlining technique.

Fiber-optic proximity sensor

NASA Technical Reports Server (NTRS)

Bejczy, A. K.; Hermann, W. A.; Primus, H. C.

1980-01-01

Proximity sensor for mechanical hand of remote manipulator incorporates fiber optics to conduct signals between light source and light detector. Fiber optics are not prone to noise from electromagnetic interference and radio-frequency interference as are sensors using long electrical cables.

Testing parameters of TMR heads affected by dynamic-tester induced EMI

NASA Astrophysics Data System (ADS)

Kruesubthaworn, A.; Sivaratana, R.; Ungvichian, V.; Siritaratiwat, A.

2007-09-01

A variety of expected electromagnetic interference (EMI) sources of both radiated and conducted EMI emissions produced by a dynamic tester is studied. It is determined that the power cable connector of the robot arm radiates a significant electric field (E-field) of about 197 V/m at 1 foot away and an estimated calculation of the E-field of about 212 mV/m is at the spindle motor. These fields can be attenuated by about 20-30 dB when using a copper lined Faraday's cage. Furthermore, the study has revealed that the radiated EMI plays a more significant role than the conducted EMI. In addition, it is determined that out of seven selected testing parameters, the SGAW is rather more sensitive to EMI than conventional failure parameters, especially static glitche during the write cycle.

Apparent hyperthyroidism caused by biotin-like interference from IgM anti-streptavidin antibodies.

PubMed

Lam, Leo; Bagg, Warwick; Smith, Geoff; Chiu, Weldon; Middleditch, Martin James; Lim, Julie Ching-Hsia; Kyle, Campbell Vance

2018-05-29

Exclusion of analytical interference is important when there is discrepancy between clinical and laboratory findings. However, interferences on immunoassays are often mistaken as isolated laboratory artefacts. We characterized and report the mechanism of a rare cause of interference in two patients that caused erroneous thyroid function tests, and also affects many other biotin dependent immunoassays. Patient 1 was a 77 y female with worsening fatigue while taking carbimazole over several years. Her thyroid function tests however, were not suggestive of hypothyroidism. Patient 2 was a 25 y female also prescribed carbimazole for apparent primary hyperthyroidism. Despite an elevated FT4, the lowest TSH on record was 0.17mIU/L. In both cases, thyroid function tests performed by an alternative method were markedly different. Further characterization of both patients' serum demonstrated analytical interference on many immunoassays using the biotin-streptavidin interaction. Sandwich assays (e.g. TSH, FSH, TNT, beta-HCG) were falsely low, while competitive assays (e.g. FT4, FT3, TBII) were falsely high. Pre-incubation of serum with streptavidin microparticles removed the analytical interference, initially suggesting the cause of interference was biotin, however, neither patient had been taking biotin. Instead, a ~100kDa IgM immunoglobulin with high affinity to streptavidin was isolated from each patient's serum. The findings confirm IgM anti-streptavidin antibodies as the cause of analytical interference. We describe two patients with apparent hyperthyroidism as a result of analytical interference caused by IgM anti-streptavidin antibodies. Analytical interference identified on one immunoassay should raise the possibility of other affected results. Characterization of interference may help to identify other potentially affected immunoassays. In the case of anti-streptavidin antibodies, the pattern of interference mimics that due to biotin ingestion; however, the degree of interference varies between individual assays and between patients.

Long-term Vihangam Yoga meditation and scores on tests of attention.

PubMed

Prakash, Ravi; Dubey, Indu; Abhishek, Priyadarshee; Gupta, Sanjeev Kumar; Rastogi, Priyanka; Siddiqui, Shazia Veqar

2010-06-01

Although the literature indicates that meditation has beneficial effects on several aspects of human functioning, few studies have specifically investigated the effects of meditation on various domains of attention. This study was conducted to examine the differences in various domains of attention between long-term concentrative meditators versus matched controls. 15 practitioners of Vihangam Yoga (> 10 yr. experience) were enrolled in the study. Controls matched on age, sex, and years of education were recruited. Both groups were administered the Stroop, Trail-Making, and Digit Symbol Substitution tests as well as the Digit Forward and Digit Backward tests. The group of Vihangam Yogis had significantly better mean performance on all tests of attention. Long-term Vihangam Yoga meditation improves attention span, processing speed, attention alternation ability, and performance in interference tests.

40 CFR 80.47 - Performance-based Analytical Test Method Approach.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chemistry and statistics, or at least a bachelor's degree in chemical engineering, from an accredited... be compensated for any known chemical interferences using good laboratory practices. (3) The test... section, individual test results shall be compensated for any known chemical interferences using good...

An Evaluation of the Eclox Chemiluminescence Test, Hach Pesticide/Nerve Agent Test Strips, and Agri-Screen Test Tickets

DTIC Science & Technology

2010-06-30

Interference Testing Our testing shows that it is unlikely that the Eclox Chemiluminescence Test will respond to the common disinfectant chloramine ...common disinfectants (chlorine and chloramine ), cyanobacterial byproducts (geosmin and MIB) or water quality parameters (humic/fulvic acids or water...toxicity sensor testing Table 2-2: Interferences Test Chemicals Concentration (mg/L) Chlorine 10 Chloramines 10 Geosmin 0.0001 Methyl-isoborneol

Compound simulator IR radiation characteristics test and calibration

NASA Astrophysics Data System (ADS)

Li, Yanhong; Zhang, Li; Li, Fan; Tian, Yi; Yang, Yang; Li, Zhuo; Shi, Rui

2015-10-01

The Hardware-in-the-loop simulation can establish the target/interference physical radiation and interception of product flight process in the testing room. In particular, the simulation of environment is more difficult for high radiation energy and complicated interference model. Here the development in IR scene generation produced by a fiber array imaging transducer with circumferential lamp spot sources is introduced. The IR simulation capability includes effective simulation of aircraft signatures and point-source IR countermeasures. Two point-sources as interference can move in two-dimension random directions. For simulation the process of interference release, the radiation and motion characteristic is tested. Through the zero calibration for optical axis of simulator, the radiation can be well projected to the product detector. The test and calibration results show the new type compound simulator can be used in the hardware-in-the-loop simulation trial.

Applications research in ultrasonic testing of carbon fiber composite based on an optical fiber F-p sensor

NASA Astrophysics Data System (ADS)

Shan, Ning

2016-10-01

Carbon fiber composite is widely applied to the field of aerospace engineering because of its excellent performance. But it will be able to form more defects in the process of manufacturing inevitably on account of unique manufacturing process. Meanwhile it has sophisticated structure and services in the bad environment long time. The existence of defects will be able to cause the sharp decline in component's performance when the defect accumulates to a certain degree. So the reliability and safety test demand of carbon fiber composite is higher and higher. Ultrasonic testing technology is the important means used for characteristics of component inspection of composite materials. Ultrasonic information detection uses acoustic transducer generally. It need coupling agent and is higher demand for the surface of sample. It has narrow frequency band and low test precision. The extrinsic type optical fiber F-P interference cavity structure is designed to this problem. Its optical interference model is studied. The initial length of F-P cavity is designed. The realtime online detection system of carbon fiber composite is established based on optical fiber F-P Ultrasound sensing technology. Finally, the testing experiment study is conducted. The results show that the system can realize real-time online detection of carbon fiber composite's defect effectively. It operates simply and realizes easily. It has low cost and is easy to practical engineering.

Testing complex animal cognition: Concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A

2018-01-01

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel-stimulus transfer eventually resulting in full abstract-concept learning. Concept-learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial-unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive-interference functions revealed time-based interference for pigeons (1, 10 s delays), but event-based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list-memory tasks by expanding the sample to four samples in trial-unique sessions (minimizing proactive interference). The four-item, list-memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed. © 2018 Society for the Experimental Analysis of Behavior.

Stroop-interference effect in post-traumatic stress disorder.

PubMed

Cui, Hong; Chen, Guoliang; Liu, Xiaohui; Shan, Moshui; Jia, Yanyan

2014-12-01

To investigate the conflict processing in posttraumatic stress disorder (PTSD) patients, we conducted the classical Stroop task by recording event-related potentials. Although the reaction time was overall slower for PTSD patients than healthy age-matched control group, the Stroop-interference effect of reaction time did not differ between the two groups. Compared with normal controls, the interference effects of N 2 and N 450 components were larger and the interference effect of slow potential component disappeared in PTSD. These data indicated the dysfunction of conflict processing in individuals with PTSD.

Traditional test administration and proactive interference undermine visual-spatial working memory performance in schizophrenia-spectrum disorders.

PubMed

Girard, Todd A; Wilkins, Leanne K; Lyons, Kathleen M; Yang, Lixia; Christensen, Bruce K

2018-05-31

Introduction Working-memory (WM) is a core cognitive deficit among individuals with Schizophrenia Spectrum Disorders (SSD). However, the underlying cognitive mechanisms of this deficit are less known. This study applies a modified version of the Corsi Block Test to investigate the role of proactive interference in visuospatial WM (VSWM) impairment in SSD. Methods Healthy and SSD participants completed a modified version of the Corsi Block Test involving both high (typical ascending set size from 4 to 7 items) and low (descending set size from 7 to 4 items) proactive interference conditions. Results The results confirmed that the SSD group performed worse overall relative to a healthy comparison group. More importantly, the SSD group demonstrated greater VSWM scores under low (Descending) versus high (Ascending) proactive interference; this pattern is opposite to that of healthy participants. Conclusions This differential pattern of performance supports that proactive interference associated with the traditional administration format contributes to VSWM impairment in SSD. Further research investigating associated neurocognitive mechanisms and the contribution of proactive interference across other domains of cognition in SSD is warranted.

Direct observation of phase-sensitive Hong-Ou-Mandel interference

NASA Astrophysics Data System (ADS)

Marek, Petr; Zapletal, Petr; Filip, Radim; Hashimoto, Yosuke; Toyama, Takeshi; Yoshikawa, Jun-ichi; Makino, Kenzo; Furusawa, Akira

2017-09-01

The quality of individual photons and their ability to interfere are traditionally tested by measuring the Hong-Ou-Mandel photon bunching effect. However, this phase-insensitive measurement only tests the particle aspect of the quantum interference, leaving out the phase-sensitive aspects relevant for continuous-variable processing. To overcome these limitations we formulate a witness capable of recognizing both the indistinguishability of the single photons and their quality with regard to their continuous-variable utilization. We exploit the conditional nonclassical squeezing and show that it can reveal both the particle and the wave aspects of the quantum interference in a single set of direct measurements. We experimentally test the witness by applying it to a pair of independent single photons retrieved on demand.

Comparison of Commercial EMI Test Techniques to NASA EMI Test Techniques

NASA Astrophysics Data System (ADS)

Smith, Valerie

2000-11-01

This systems report describes how the Optical Properties Monitor (OPM) experiment was developed. Pertinent design parameters are discussed, along with mission information and system requirements to successfully complete the mission. Environmental testing was performed on the OPM to certify it for spaceflight. This testing included vibration, thermal vacuum, electromagnetic interference and conductance, and toxicity tests. Instrument and monitor subsystem performances, including the reflectometer, vacuum ultraviolet, total integrated scatter, atomic oxygen monitor, irradiance monitor, and molecular contamination monitor during the mission are discussed. The OPM experiment was launched aboard the Space Shuttle on mission STS-81 in January 1997 and transferred to the Mir space station. An extravehicular activity (EVA) was performed in April 1997 to attach the OPM experiment to the outside of the Mir/Shuttle Docking Module for space environment exposure. The OPM conducted in situ measurements of a number of material samples. These data may be found in the OPM Science Report. OPM was retrieved during an EVA in January 1998 and was returned to Earth on board the Space Shuttle on mission STS-89.

The Role of Test Expectancy in the Build-Up of Proactive Interference in Long-Term Memory

ERIC Educational Resources Information Center

Weinstein, Yana; Gilmore, Adrian W.; Szpunar, Karl K.; McDermott, Kathleen B.

2014-01-01

We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not…

Speed and Lateral Inhibition of Stimulus Processing Contribute to Individual Differences in Stroop-Task Performance.

PubMed

Naber, Marnix; Vedder, Anneke; Brown, Stephen B R E; Nieuwenhuis, Sander

2016-01-01

The Stroop task is a popular neuropsychological test that measures executive control. Strong Stroop interference is commonly interpreted in neuropsychology as a diagnostic marker of impairment in executive control, possibly reflecting executive dysfunction. However, popular models of the Stroop task indicate that several other aspects of color and word processing may also account for individual differences in the Stroop task, independent of executive control. Here we use new approaches to investigate the degree to which individual differences in Stroop interference correlate with the relative processing speed of word and color stimuli, and the lateral inhibition between visual stimuli. We conducted an electrophysiological and behavioral experiment to measure (1) how quickly an individual's brain processes words and colors presented in isolation (P3 latency), and (2) the strength of an individual's lateral inhibition between visual representations with a visual illusion. Both measures explained at least 40% of the variance in Stroop interference across individuals. As these measures were obtained in contexts not requiring any executive control, we conclude that the Stroop effect also measures an individual's pre-set way of processing visual features such as words and colors. This study highlights the important contributions of stimulus processing speed and lateral inhibition to individual differences in Stroop interference, and challenges the general view that the Stroop task primarily assesses executive control.

Sleep can reduce proactive interference.

PubMed

Abel, Magdalena; Bäuml, Karl-Heinz T

2014-01-01

Sleep has repeatedly been connected to processes of memory consolidation. While extensive research indeed documents beneficial effects of sleep on memory, little is yet known about the role of sleep for interference effects in episodic memory. Although two prior studies reported sleep to reduce retroactive interference, no sleep effect has previously been found for proactive interference. Here we applied a study format differing from that employed by the prior studies to induce a high degree of proactive interference, and asked participants to encode a single list or two interfering lists of paired associates via pure study cycles. Testing occurred after 12 hours of diurnal wakefulness or nocturnal sleep. Consistent with the prior work, we found sleep in comparison to wake did not affect memory for the single list, but reduced retroactive interference. In addition we found sleep reduced proactive interference, and reduced retroactive and proactive interference to the same extent. The finding is consistent with the view that arising benefits of sleep are caused by the reactivation of memory contents during sleep, which has been suggested to strengthen and stabilise memories. Such stabilisation may make memories less susceptible to competition from interfering memories at test and thus reduce interference effects.

Interpretation of hydraulic conductivity in a fractured-rock aquifer over increasingly larger length dimensions

USGS Publications Warehouse

Shapiro, Allen M.; Ladderud, Jeffery; Yager, Richard M.

2015-01-01

A comparison of the hydraulic conductivity over increasingly larger volumes of crystalline rock was conducted in the Piedmont physiographic region near Bethesda, Maryland, USA. Fluid-injection tests were conducted on intervals of boreholes isolating closely spaced fractures. Single-hole tests were conducted by pumping in open boreholes for approximately 30 min, and an interference test was conducted by pumping a single borehole over 3 days while monitoring nearby boreholes. An estimate of the hydraulic conductivity of the rock over hundreds of meters was inferred from simulating groundwater inflow into a kilometer-long section of a Washington Metropolitan Area Transit Authority tunnel in the study area, and a groundwater modeling investigation over the Rock Creek watershed provided an estimate of the hydraulic conductivity over kilometers. The majority of groundwater flow is confined to relatively few fractures at a given location. Boreholes installed to depths of approximately 50 m have one or two highly transmissive fractures; the transmissivity of the remaining fractures ranges over five orders of magnitude. Estimates of hydraulic conductivity over increasingly larger rock volumes varied by less than half an order of magnitude. While many investigations point to increasing hydraulic conductivity as a function of the measurement scale, a comparison with selected investigations shows that the effective hydraulic conductivity estimated over larger volumes of rock can either increase, decrease, or remain stable as a function of the measurement scale. Caution needs to be exhibited in characterizing effective hydraulic properties in fractured rock for the purposes of groundwater management.

Modification of Rhodamine WT tracer tests procedure in activated sludge reactors

NASA Astrophysics Data System (ADS)

Knap, Marta; Balbierz, Piotr

2017-11-01

One of the tracers recommended for use in wastewater treatment plants and natural waters is Rhodamine WT, which is a fluorescent dye, allowing to work at low concentrations, but may be susceptible to sorption to activated sludge flocs and chemical quenching of fluorescence by dissolved water constituents. Additionally raw sewage may contain other natural materials or pollutants exhibiting limited fluorescent properties, which are responsible for background fluorescence interference. This paper presents the proposed modifications to the Rhodamine WT tracer tests procedure in activated sludge reactors, which allow to reduce problems with background fluorescence and tracer loss over time, developed on the basis of conducted laboratory and field experiments.

Determination of anionic surfactants during wastewater recycling process by ion pair chromatography with suppressed conductivity detection

NASA Technical Reports Server (NTRS)

Levine, L. H.; Judkins, J. E.; Garland, J. L.; Sager, J. C. (Principal Investigator)

2000-01-01

A direct approach utilizing ion pairing reversed-phase chromatography coupled with suppressed conductivity detection was developed to monitor biodegradation of anionic surfactants during wastewater recycling through hydroponic plant growth systems and fixed-film bioreactors. Samples of hydroponic nutrient solution and bioreactor effluent with high concentrations (up to 120 mS electrical conductance) of inorganic ions can be analyzed without pretreatment or interference. The presence of non-ionic surfactants did not significantly affect the analysis. Dynamic linear ranges for tested surfactants [Igepon TC-42, ammonium lauryl sulfate, sodium laureth sulfate and sodium alkyl (C10-C16) ether sulfate] were 2 to approximately 500, 1 to approximately 500, 2.5 to approximately 550 and 3.0 to approximately 630 microg/ml, respectively.

Sources of Interference in Recognition Testing

ERIC Educational Resources Information Center

Annis, Jeffrey; Malmberg, Kenneth J.; Criss, Amy H.; Shiffrin, Richard M.

2013-01-01

Recognition memory accuracy is harmed by prior testing (a.k.a., output interference [OI]; Tulving & Arbuckle, 1966). In several experiments, we interpolated various tasks between recognition test trials. The stimuli and the tasks were more similar (lexical decision [LD] of words and nonwords) or less similar (gender identification of male and…

Attitudes toward sex, arousal, and the retention of contraceptive information.

PubMed

Goldfarb, L; Gerrard, M; Gibbons, F X; Plante, T

1988-10-01

Previous research has suggested that women with a negative emotional orientation toward sexuality (i.e., erotophobia) have difficulty learning and retaining sexually relevant material such as contraceptive information. It has been hypothesized that these women become aroused by this material and that this arousal interferes with their ability to learn it. The importance of this issue led us to conduct the current study. Erotophobic and erotophilic women viewed presentations about contraception while their physiological responses were being monitored. In addition, they were tested on the information contained in the presentation before, immediately after, and again 4-6 weeks after the presentation. The results indicated that the erotophobic women knew less contraceptive information before the presentation and were more aroused by the presentation. This arousal, however, did not interfere with retention of the material. These results are discussed in terms of individual differences in reactions to sexual material and the ability to learn, retain, and use contraceptive information.

Magnetoplasma sheath waves on a conducting tether in the ionosphere with applications to EMI propagation on large space structures

NASA Technical Reports Server (NTRS)

Balmain, K. G.; James, H. G.; Bantin, C. C.

1991-01-01

A recent space experiment confirmed sheath-wave propagation of a kilometer-long insulated wire in the ionosphere, oriented parallel to the Earth's magnetic field. This space tether experiment, Oedipus-A, showed a sheath-wave passband up to about 2 MHz and a phase velocity somewhat slower than the velocity of light in a vacuum, and also demonstrated both ease of wave excitation and low attenuation. The evidence suggests that, on any large structure in low Earth orbit, transient or continuous wave electromagnetic interference, once generated, could propagate over the structure via sheath waves, producing unwanted signal levels much higher than in the absence of the ambient plasma medium. Consequently, there is a need for a review of both electromagnetic interference/electromagnetic compatibility standards and ground test procedures as they apply to large structures in low Earth orbit.

Release from Proactive Interference: Insufficiency of an Attentional Account

ERIC Educational Resources Information Center

MacLeod, Colin M.

1975-01-01

If an attentional cue affects retroactive interference, perhaps a similar mechanism underlies release from proactive interference. This study tested this hypothesis by inserting an attentional cue before the final trial in Wickens' paradigm. (Author/RK)

Shear wave speed recovery using moving interference patterns obtained in sonoelastography experiments.

PubMed

McLaughlin, Joyce; Renzi, Daniel; Parker, Kevin; Wu, Zhe

2007-04-01

Two new experiments were created to characterize the elasticity of soft tissue using sonoelastography. In both experiments the spectral variance image displayed on a GE LOGIC 700 ultrasound machine shows a moving interference pattern that travels at a very small fraction of the shear wave speed. The goal of this paper is to devise and test algorithms to calculate the speed of the moving interference pattern using the arrival times of these same patterns. A geometric optics expansion is used to obtain Eikonal equations relating the moving interference pattern arrival times to the moving interference pattern speed and then to the shear wave speed. A cross-correlation procedure is employed to find the arrival times; and an inverse Eikonal solver called the level curve method computes the speed of the interference pattern. The algorithm is tested on data from a phantom experiment performed at the University of Rochester Center for Biomedical Ultrasound.

Interference effects on commonly used memory tasks.

PubMed

Brophy, Linda M; Jackson, Martin; Crowe, Simon F

2009-02-01

This paper reports two studies which investigated the effect of interference on delayed recall scores of the WMS-III and other commonly used memory measures. In Study 1, participants completed the immediate and delayed components of the WMS-III, with or without the introduction of conceptually similar memory tasks between the recall trials. In Study 2, this order of administration was reversed, with the WMS-III subtests used as the interference items. The results indicated that the introduction of interference items during the delay negatively affected delayed recall performance on almost all sub-tests. In addition, equal effects of proactive and retroactive interference were demonstrated. These findings raise concerns regarding the standardization process for memory tasks and highlight the need to consider interference effects in clinical practice, and stand as a caution in the use of memory-related materials during the delay interval in memory testing.

Contextual interference effects on the acquisition of skill and strength of the bench press.

PubMed

Naimo, Marshall A; Zourdos, Michael C; Wilson, Jacob M; Kim, Jeong-Su; Ward, Emery G; Eccles, David W; Panton, Lynn B

2013-06-01

The purpose of this study was to investigate contextual interference effects on skill acquisition and strength gains during the learning of the bench press movement. Twenty-four healthy, college-aged males and females were stratified to control, high contextual interference (HCI), and low contextual interference (LCI) groups. Treatment groups were provided with written and visual instruction on proper bench press form and practiced the bench press and dart throwing for four weeks. Within each session, LCI performed all bench press sets before undertaking dart-throws. HCI undertook dart-throws immediately following each set of bench press. Control only did testing. Measurements, including one repetition maximum (1RM), checklist scores based on video recordings of participants' 1RM's, and dart-throw test scores were taken at pre-test, 1 week, 2 week, post-test, and retention test. Results were consistent with the basic premise of the contextual interference effect. LCI had significant improvements in percent 1RM and checklist scores during training, but were mostly absent after training (post-test and retention test). HCI had significant improvements in percent 1RM and checklist scores both during and after training. Thus, HCI may augment strength and movement skill on the bench press since proper technique is an important component of resistance exercise movements. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental and Theoretical Study of Propeller Spinner/Shank Interference. M.S. Thesis

NASA Technical Reports Server (NTRS)

Cornell, C. C.

1986-01-01

A fundamental experimental and theoretical investigation into the aerodynamic interference associated with propeller spinner and shank regions was conducted. The research program involved a theoretical assessment of solutions previously proposed, followed by a systematic experimental study to supplement the existing data base. As a result, a refined computational procedure was established for prediction of interference effects in terms of interference drag and resolved into propeller thrust and torque components. These quantities were examined with attention to engineering parameters such as two spinner finess ratios, three blade shank forms, and two/three/four/six/eight blades. Consideration of the physics of the phenomena aided in the logical deduction of two individual interference quantities (cascade effects and spinner/shank juncture interference). These interference effects were semi-empirically modeled using existing theories and placed into a compatible form with an existing propeller performance scheme which provided the basis for examples of application.

Bone anchors or interference screws? A biomechanical evaluation for autograft ankle stabilization.

PubMed

Jeys, Lee; Korrosis, Sotiris; Stewart, Todd; Harris, Nicholas J

2004-01-01

Autograft stabilization uses free semitendinosus tendon grafts to anatomically reconstruct the anterior talofibular ligament. Study aims were to evaluate the biomechanical properties of Mitek GII anchors compared with the Arthrex Bio-Tenodesis Screw for free tendon reconstruction of the anterior talofibular ligament. There are no differences in load to failure and percentage specimen elongation at failure between the 2 methods. Controlled laboratory study using porcine models. Sixty porcine tendon constructs were failure tested. Re-creating the pull of the anterior talofibular ligament, loads were applied at 70 degrees to the bones. Thirty-six tendons were fixed to porcine tali and tested using a single pull to failure; 10 were secured with anchors and No. 2 Ethibond, 10 with anchors and FiberWire, 10 with screws and Fiberwire, and 6 with partially gripped screws. Cyclic preloading was conducted on 6 tendons fixed by anchors and on 6 tendons fixed by screws before failure testing. Two groups of 6 components fixed to the fibula were also tested. The talus single-pull anchor group produced a mean load of 114 N and elongation of 37% at failure. The talus single-pull screw group produced a mean load of 227 N and elongation of 22% at failure (P <.05). Cyclic preloading at 65% failure load before failure testing produced increases in load and decreases in elongation at failure. Partially gripped screws produced a load of 133 N and elongation of 30% at failure. The fibula model produced significant increases in load to failure for both. The human anterior talofibular ligament has loads of 139 N at failure with instability occurring at 20% elongation. Interference screw fixation produced significantly greater failure strength and less elongation at failure than bone anchors. The improved biomechanics of interference screws suggests that these may be more suited to in vivo reconstruction of the anterior talofibular ligament than are bone anchors.

Experimental Results of the 2.7% Reference H Nacelle Airframe Interference High Speed Civil Transport Model

NASA Technical Reports Server (NTRS)

Cappuccio, Gelsomina

1999-01-01

Experiments were conducted in the NASA Ames 9-Ft by 7-Ft Supersonic and 11-Ft by 11-Ft Transonic Wind Tunnels of a 2.7% Reference H (Ref. H) Nacelle Airframe Interference (NAI) High Speed Civil Transport (HSCT) model. NASA Ames did the experiment with the cooperation and assistance of Boeing and McDonnell Douglas. The Ref. H geometry was designed by Boeing. The model was built and tested by NASA under a license agreement with Boeing. Detailed forces and pressures of individual components of the configuration were obtained to assess nacelle airframe interference through the transonic and supersonic flight regime. The test apparatus was capable of measuring forces and pressures of the Wing body (WB) and nacelles. Axisymmetric and 2-D inlet nacelles were tested with the WB in both the in-proximity and captive mode. The in-proximity nacelles were mounted to a nacelle support system apparatus and were individually positioned. The right hand nacelles were force instrumented with flow through strain-gauged balances and the left hand nacelles were pressure instrumented. Mass flow ratio was varied to get steady state inlet unstart data. In addition, supersonic spillage data was taken by testing the 2-D inlet nacelles with ramps and the axisymmetric inlet nacelles with an inlet centerbody for the Mach condition of interest. The captive nacelles, both axisymmetric and 2-D, were attached to the WB via diverters. The captive 2-D inlet nacelle was also tested with ramps to get supersonic spillage data. Boeing analyzed the data and showed a drag penalty of four drag counts for the 2-D compared with the axisymmetric inlet nacelle. Two of the four counts were attributable to the external bevel designed into the 2-D inlet contour. Boeing and McDonnell Douglas used these data for evaluating Computational Fluid Dynamic (CFD) codes and for evaluation of nacelle airframe integration problems and solutions.

Experimental study of main rotor tip geometry and tail rotor interactions in hover. Volume 2: Run log and tabulated data

NASA Technical Reports Server (NTRS)

Balch, D. T.; Lombardi, J.

1985-01-01

A model scale hover test was conducted in the Sikorsky Aircraft Model Rotor hover Facility to identify and quantify the impact of the tail rotor on the demonstrated advantages of advanced geometry tip configurations. The existence of mutual interference between hovering main rotor and a tail rotor was acknowledged in the test. The test was conducted using the Basic Model Test Rig and two scaled main rotor systems, one representing a 1/5.727 scale UH-60A BLACK HAWK and the others a 1/4.71 scale S-76. Eight alternate rotor tip configurations were tested, 3 on the BLACK HAWK rotor and 6 on the S-76 rotor. Four of these tips were then selected for testing in close proximity to an operating tail rotor (operating in both tractor and pusher modes) to determine if the performance advantages that could be obtained from the use of advanced geometry tips in a main rotor only environment would still exist in the more complex flow field involving a tail rotor. This volume contains the test run log and tabulated data.

Event-related potential evidence for separable automatic and controlled retrieval processes in proactive interference.

PubMed

Bergström, Zara M; O'Connor, Richard J; Li, Martin K-H; Simons, Jon S

2012-05-21

Interference between competing memories is a major source of retrieval failure, yet, surprisingly little is known about how competitive memory activation arises in the brain. One possibility is that interference during episodic retrieval might be produced by relatively automatic conceptual priming mechanisms that are independent of strategic retrieval processes. Such priming-driven interference might occur when the competing memories have strong pre-existing associations to the retrieval cue. We used ERPs to measure the neural dynamics of retrieval competition, and investigated whether the ERP correlates of interference were affected by varying task demands for selective retrieval. Participants encoded cue words that were presented either two or four times, paired either with the same or different strongly associated words across repetitions. In a subsequent test, participants either selectively recalled each cue's most recent associate, or simply judged how many times a cue had been presented, without requiring selective recall. Interference effects on test performance were only seen in the recall task. In contrast, ERPs during test revealed an early posterior positivity for high interference items that was present in both retrieval tasks. This early ERP effect likely reflects a conceptual priming-related N400 reduction when many associations to a cue were pre-activated. A later parietal positivity resembling the ERP correlate of conscious recollection was found only in the recall task. The results suggest that early effects of proactive interference are relatively automatic and independent of intentional retrieval processes, consistent with suggestions that interference can arise through conceptual priming. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of Commercial Electromagnetic Interface Test Techniques to NASA Electromagnetic Interference Test Techniques

NASA Astrophysics Data System (ADS)

Smith, V.

2000-11-01

This report documents the development of analytical techniques required for interpreting and comparing space systems electromagnetic interference test data with commercial electromagnetic interference test data using NASA Specification SSP 30237A "Space Systems Electromagnetic Emission and Susceptibility Requirements for Electromagnetic Compatibility." The PSpice computer simulation results and the laboratory measurements for the test setups under study compare well. The study results, however, indicate that the transfer function required to translate test results of one setup to another is highly dependent on cables and their actual layout in the test setup. Since cables are equipment specific and are not specified in the test standards, developing a transfer function that would cover all cable types (random, twisted, or coaxial), sizes (gauge number and length), and layouts (distance from the ground plane) is not practical.

Comparison of Commercial Electromagnetic Interface Test Techniques to NASA Electromagnetic Interference Test Techniques

NASA Technical Reports Server (NTRS)

Smith, V.; Minor, J. L. (Technical Monitor)

2000-01-01

This report documents the development of analytical techniques required for interpreting and comparing space systems electromagnetic interference test data with commercial electromagnetic interference test data using NASA Specification SSP 30237A "Space Systems Electromagnetic Emission and Susceptibility Requirements for Electromagnetic Compatibility." The PSpice computer simulation results and the laboratory measurements for the test setups under study compare well. The study results, however, indicate that the transfer function required to translate test results of one setup to another is highly dependent on cables and their actual layout in the test setup. Since cables are equipment specific and are not specified in the test standards, developing a transfer function that would cover all cable types (random, twisted, or coaxial), sizes (gauge number and length), and layouts (distance from the ground plane) is not practical.

Investigation of Mechanical and Electromagnetic Interference Shielding Properties of Nickel-CFRP Textile Composites

NASA Astrophysics Data System (ADS)

Tugirumubano, Alexandre; Vijay, Santhiyagu Joseph; Go, Sun Ho; Kwac, Lee Ku; Kim, Hong Gun

2018-05-01

The most common materials used for electromagnetic interference shielding are metals and their alloys. However, those materials are heavy and highly reflective. In order to eliminate or reduce the intensity of wave radiation in their working environment, lightweight materials that have interference shielding properties are needed. In this paper, nickel wire mesh yarns (warps) were woven into carbon fibers-reinforced plastic yarns (wefts) to produce metal-carbon textile composite materials. The plain weave and 2/2 twill weave techniques were used, and the woven fabrics were laminated to manufacture experimental test samples. The nickel, which has high magnetic permeability and good electric conductivity, and carbon fibers, which have good electrical, thermal and mechanical properties, were used together to achieve the desired properties. The shielding effectiveness of each sample was investigated using a network analyzer connected with coaxial transmission line test in accordance with ASTM 4935-99 standard, with the frequencies ranging from 500 MHz to 1.5 GHz. Here, the plain weave structure showed higher shielding effectiveness than twill weave. The absorption losses for both materials were relatively greater than reflection losses. In reference to the orientation of wire mesh yarns about the loading axis, the tensile strengths in the transversal direction were 19.04 and 16.34% higher than the tensile strengths in longitudinal direction for plain weave and twill weave, respectively. The fractography analysis with SEM showed a ductile fracture of wire mesh and brittle fracture of epoxy matrix and carbon fibers.

Investigation of Mechanical and Electromagnetic Interference Shielding Properties of Nickel-CFRP Textile Composites

NASA Astrophysics Data System (ADS)

Tugirumubano, Alexandre; Vijay, Santhiyagu Joseph; Go, Sun Ho; Kwac, Lee Ku; Kim, Hong Gun

2018-04-01

The most common materials used for electromagnetic interference shielding are metals and their alloys. However, those materials are heavy and highly reflective. In order to eliminate or reduce the intensity of wave radiation in their working environment, lightweight materials that have interference shielding properties are needed. In this paper, nickel wire mesh yarns (warps) were woven into carbon fibers-reinforced plastic yarns (wefts) to produce metal-carbon textile composite materials. The plain weave and 2/2 twill weave techniques were used, and the woven fabrics were laminated to manufacture experimental test samples. The nickel, which has high magnetic permeability and good electric conductivity, and carbon fibers, which have good electrical, thermal and mechanical properties, were used together to achieve the desired properties. The shielding effectiveness of each sample was investigated using a network analyzer connected with coaxial transmission line test in accordance with ASTM 4935-99 standard, with the frequencies ranging from 500 MHz to 1.5 GHz. Here, the plain weave structure showed higher shielding effectiveness than twill weave. The absorption losses for both materials were relatively greater than reflection losses. In reference to the orientation of wire mesh yarns about the loading axis, the tensile strengths in the transversal direction were 19.04 and 16.34% higher than the tensile strengths in longitudinal direction for plain weave and twill weave, respectively. The fractography analysis with SEM showed a ductile fracture of wire mesh and brittle fracture of epoxy matrix and carbon fibers.

Space Launch System Ascent Static Aerodynamic Database Development

NASA Technical Reports Server (NTRS)

Pinier, Jeremy T.; Bennett, David W.; Blevins, John A.; Erickson, Gary E.; Favaregh, Noah M.; Houlden, Heather P.; Tomek, William G.

2014-01-01

This paper describes the wind tunnel testing work and data analysis required to characterize the static aerodynamic environment of NASA's Space Launch System (SLS) ascent portion of flight. Scaled models of the SLS have been tested in transonic and supersonic wind tunnels to gather the high fidelity data that is used to build aerodynamic databases. A detailed description of the wind tunnel test that was conducted to produce the latest version of the database is presented, and a representative set of aerodynamic data is shown. The wind tunnel data quality remains very high, however some concerns with wall interference effects through transonic Mach numbers are also discussed. Post-processing and analysis of the wind tunnel dataset are crucial for the development of a formal ascent aerodynamics database.

Electrical conductivity and electromagnetic interference shielding of epoxy nanocomposite foams containing functionalized multi-wall carbon nanotubes

NASA Astrophysics Data System (ADS)

Li, Jiantong; Zhang, Guangcheng; Zhang, Hongming; Fan, Xun; Zhou, Lisheng; Shang, Zhengyang; Shi, Xuetao

2018-01-01

Epoxy/functionalized multi-wall carbon nanotube (EP/F-MWCNT) microcellular foams were fabricated through a supercritical CO2 (scCO2) foaming method. MWCNTs with carboxylation treatment were disentangled by using alpha-zirconium phosphate (ZrP) assisting dispersion method and functionalized with sulfanilamide. The F-MWCNTs were redispersed in acetone for mixing with epoxy resins to prepare nanocomposites. It was found that the dispersion of MWCNTs could be improved, thus heterogeneous nucleation effect of F-MWCNTs took place effectively during the foaming process, resulting in the formation of microcellular structure with larger cell density and smaller cell size. The volume conductivity and electromagnetic interference shielding performance of foamed EP/F-MWCNT nanocomposites were studied. When the F-MWCNT addition was 5 wt%, the conductivity of the foamed EP/F-MWCNT nanocomposites was 3.02 × 10-4 S/cm and the EMI shielding effectiveness (SE) reached 20.5 dB, significantly higher than the corresponding results of nanocomposite counterparts, indicating that introducing microcellular structure in EP/F-MWCNT nanocomposites would beneficial to improve their electrical conductivity and electromagnetic interference shielding performance.

Ascent heat transfer rate distribution on the North American Rockwell delta wing orbiter and the General Dynamics/Convair booster at a Mach number of 8 (mated)

NASA Technical Reports Server (NTRS)

Matthews, R. K.; Martindale, W. R.; Warmbrod, J. D.

1972-01-01

A wind tunnel test program to determine aerodynamic interference heating on the North American Rockwell orbiter mated with the General Dynamics Convair booster is discussed. The tests were conducted at the Arnold Engineering Development Center (AEDC) in Tunnel B of the von Karman Gas Dynamics Facility (VKF). The test period was June 1971. Heat-transfer rates were determined by the phase-change paint technique on 0.013-scale Stycast models using Tempilaq as the surface temperature indicator. The nominal test conditions were: Mach 8, free-stream unit length Reynolds numbers of 1.25 x one million and 2.55 x one million angles of attack of -5, 0, +5 deg. Model details, test conditions, phase-change paint photographs and reduced heat-transfer coefficients are presented.

Quantum-ring spin interference device tuned by quantum point contacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diago-Cisneros, Leo; Mireles, Francisco

2013-11-21

We introduce a spin-interference device that comprises a quantum ring (QR) with three embedded quantum point contacts (QPCs) and study theoretically its spin transport properties in the presence of Rashba spin-orbit interaction. Two of the QPCs conform the lead-to-ring junctions while a third one is placed symmetrically in the upper arm of the QR. Using an appropriate scattering model for the QPCs and the S-matrix scattering approach, we analyze the role of the QPCs on the Aharonov-Bohm (AB) and Aharonov-Casher (AC) conductance oscillations of the QR-device. Exact formulas are obtained for the spin-resolved conductances of the QR-device as a functionmore » of the confinement of the QPCs and the AB/AC phases. Conditions for the appearance of resonances and anti-resonances in the spin-conductance are derived and discussed. We predict very distinctive variations of the QR-conductance oscillations not seen in previous QR proposals. In particular, we find that the interference pattern in the QR can be manipulated to a large extend by varying electrically the lead-to-ring topological parameters. The latter can be used to modulate the AB and AC phases by applying gate voltage only. We have shown also that the conductance oscillations exhibits a crossover to well-defined resonances as the lateral QPC confinement strength is increased, mapping the eigenenergies of the QR. In addition, unique features of the conductance arise by varying the aperture of the upper-arm QPC and the Rashba spin-orbit coupling. Our results may be of relevance for promising spin-orbitronics devices based on quantum interference mechanisms.« less

Mobile communication devices causing interference in invasive and noninvasive ventilators.

PubMed

Dang, Bao P; Nel, Pierre R; Gjevre, John A

2007-06-01

The aim of this study was to assess if common mobile communication systems would cause significant interference on mechanical ventilation devices and at what distances would such interference occur. We tested all the invasive and noninvasive ventilatory devices used within our region. This consisted of 2 adult mechanical ventilators, 1 portable ventilator, 2 pediatric ventilators, and 2 noninvasive positive pressure ventilatory devices. We operated the mobile devices from the 2 cellular communication systems (digital) and 1 2-way radio system used in our province at varying distances from the ventilators and looked at any interference they created. We tested the 2-way radio system, which had a fixed operation power output of 3.0 watts, the Global Systems for Mobile Communication cellular system, which had a maximum power output of 2.0 watts and the Time Division Multiple Access cellular system, which had a maximum power output of 0.2 watts on our ventilators. The ventilators were ventilating a plastic lung at fixed settings. The mobile communication devices were tested at varying distances starting at zero meter from the ventilator and in all operation modes. The 2-way radio caused the most interference on some of the ventilators, but the maximum distance of interference was 1.0 m. The Global Systems for Mobile Communication system caused significant interference only at 0 m and minor interference at 0.5 m on only 1 ventilator. The Time Division Multiple Access system caused no interference at all. Significant interference consisted of a dramatic rise and fluctuation of the respiratory rate, pressure, and positive end-expiratory pressure of the ventilators with no normalization when the mobile device was removed. From our experiment on our ventilators with the communication systems used in our province, we conclude that mobile communication devices such as cellular phones and 2-way radios are safe and cause no interference unless operated at very close distances of less than 1 meter.

The Improvement of Bone-Tendon Fixation by Porous Titanium Interference Screw: A Rabbit Animal Model.

PubMed

Tsai, Pei-I; Chen, Chih-Yu; Huang, Shu-Wei; Yang, Kuo-Yi; Lin, Tzu-Hung; Chen, San-Yuan; Sun, Jui-Sheng

2018-05-04

The interference screw is a widely used fixation device in the anterior cruciate ligament (ACL) reconstruction surgeries. Despite the generally satisfactory results, problems of using interference screws were reported. By using additive manufacturing (AM) technology, we developed an innovative titanium alloy (Ti 6 Al 4 V) interference screw with rough surface and inter-connected porous structure designs to improve the bone-tendon fixation. An innovative Ti 6 Al 4 V interference screws were manufactured by AM technology. In vitro mechanical tests were performed to validate its mechanical properties. Twenty-seven New Zealand white rabbits were randomly divided into control and AM screw groups for biomechanical analyses and histological analysis at 4, 8 and 12 weeks postoperatively; while micro-CT analysis was performed at 12 weeks postoperatively. The biomechanical tests showed that the ultimate failure load in the AM interference screw group was significantly higher than that in the control group at all tested periods. These results were also compatible with the findings of micro-CT and histological analyses. In micro-CT analysis, the bone-screw gap was larger in the control group; while for the additive manufactured screw, the screw and bone growth was in close contact. In histological study, the bone-screw gaps were wider in the control group and were almost invisible in the AM screw group. The innovative AM interference screws with surface roughness and inter-connected porous architectures demonstrated better bone-tendon-implant integration, and resulted in stronger biomechanical characteristics when compared to traditional screws. These advantages can be transferred to future interference screw designs to improve their clinical performance. The AM interference screw could improve graft fixation and eventually result in better biomechanical performance of the bone-tendon-screw construct. The innovative AM interference screws can be transferred to future interference screw designs to improve the performance of implants. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The color-word interference test and its relation to performance impairment under auditory distraction.

DOT National Transportation Integrated Search

1972-03-01

The ability to resist distraction is an important requirement for air traffic controllers. The study examined the relationship between performance on the Stroop color-word interference test (a suggested measure of distraction susceptibility) and impa...

Identification of algae which interfere with the detection of Giardia cysts and Cryptosporidium oocysts and a method for alleviating this interference.

PubMed Central

Rodgers, M R; Flanigan, D J; Jakubowski, W

1995-01-01

Fifty-four algal species were tested for cross-reaction in the American Society for Testing and Materials Giardia/Cryptosporidium indirect immunofluorescence assay, and 24 showed some degree of fluorescence. Two species, Navicula minima and Synechococcus elongatus, exhibited a bright apple green fluorescence. The addition of goat serum to the assay mixture blocked the fluorescence of most nontarget organisms tested and also decreased the background fluorescence. Goat serum did not interfere with the fluorescence of Giardia cysts or Cryptosporidium oocysts or the identification of cyst and oocyst internal structures. PMID:7487013

Kondo blockade due to quantum interference in single-molecule junctions

PubMed Central

Mitchell, Andrew K.; Pedersen, Kim G. L.; Hedegård, Per; Paaske, Jens

2017-01-01

Molecular electronics offers unique scientific and technological possibilities, resulting from both the nanometre scale of the devices and their reproducible chemical complexity. Two fundamental yet different effects, with no classical analogue, have been demonstrated experimentally in single-molecule junctions: quantum interference due to competing electron transport pathways, and the Kondo effect due to entanglement from strong electronic interactions. Here we unify these phenomena, showing that transport through a spin-degenerate molecule can be either enhanced or blocked by Kondo correlations, depending on molecular structure, contacting geometry and applied gate voltages. An exact framework is developed, in terms of which the quantum interference properties of interacting molecular junctions can be systematically studied and understood. We prove that an exact Kondo-mediated conductance node results from destructive interference in exchange-cotunneling. Nonstandard temperature dependences and gate-tunable conductance peaks/nodes are demonstrated for prototypical molecular junctions, illustrating the intricate interplay of quantum effects beyond the single-orbital paradigm. PMID:28492236

Wind tunnel wall interference in V/STOL and high lift testing: A selected, annotated bibliography

NASA Technical Reports Server (NTRS)

Tuttle, M. H.; Mineck, R. E.; Cole, K. L.

1986-01-01

This bibliography, with abstracts, consists of 260 citations of interest to persons involved in correcting aerodynamic data, from high lift or V/STOL type configurations, for the interference arising from the wind tunnel test section walls. It provides references which may be useful in correcting high lift data from wind tunnel to free air conditions. References are included which deal with the simulation of ground effect, since it could be viewed as having interference from three tunnel walls. The references could be used to design tests from the standpoint of model size and ground effect simulation, or to determine the available testing envelope with consideration of the problem of flow breakdown. The arrangement of the citations is chronological by date of publication in the case of reports or books, and by date of presentation in the case of papers. Included are some documents of historical interest in the development of high lift testing techniques and wall interference correction methods. Subject, corporate source, and author indices, by citation numbers, have been provided to assist the users. The appendix includes citations of some books and documents which may not deal directly with high lift or V/STOL wall interference, but include additional information which may be helpful.

A high performance sensor for triaxial cutting force measurement in turning.

PubMed

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-04-03

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%-0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning.

A High Performance Sensor for Triaxial Cutting Force Measurement in Turning

PubMed Central

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-01-01

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%–0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning. PMID:25855035

Study on influence of vibration behavior of composite material damage by holography

NASA Astrophysics Data System (ADS)

Guo, Linfeng; Zhao, Zhimin; Gao, Mingjuan; Zhuang, Xianzhong

2006-01-01

Composite material has been applied widely in aeronautics, astronautics and some other fields due to their high strength, light weight and antifatigue and etc. But in the application, composite material may be destroyed or damaged, which may have impact on its further applications. Therefore, study on the influence of behavior of composite material damage becomes a hot research. In this paper, the common composite material for aircraft is used as the test object, and a study is conducted to investigate the influence of vibration behavior of composite material damage. The authors adopt the method of light-carrier wave and time-average holography. Compared the interference fringes of composite materials before and after damage, the width of the interference fringes of hologram of the damaged composite material is narrower than that of the fringes before. It means that the off-plane displacement of each point on the test object is larger than before. Based on the elastic mechanics theory, the off-plane displacement is inverse to the bending stiffness, and the bending stiffness of the test object will decrease after it is damaged. In other words, the vibration property of the composite material changes after damages occur. The research results of the paper show that the results accord with the analysis of theory.

Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills.

PubMed

Jung, Yoojin; Han, Byunghyun; Mostafid, M Erfan; Chiu, Pei; Yazdani, Ramin; Imhoff, Paul T

2012-02-01

Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobility and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF(6)), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1-3% in landfill gas but 4-5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3-4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences. Copyright © 2011 Elsevier Ltd. All rights reserved.

NASA ERA Integrated CFD for Wind Tunnel Testing of Hybrid Wing-Body Configuration

NASA Technical Reports Server (NTRS)

Garcia, Joseph A.; Melton, John E.; Schuh, Michael; James, Kevin D.; Long, Kurtis R.; Vicroy, Dan D.; Deere, Karen A.; Luckring, James M.; Carter, Melissa B.; Flamm, Jeffrey D.;

NASA ERA Integrated CFD for Wind Tunnel Testing of Hybrid Wing-Body Configuration

NASA Technical Reports Server (NTRS)

Garcia, Joseph A.; Melton, John E.; Schuh, Michael; James, Kevin D.; Long, Kurt R.; Vicroy, Dan D.; Deere, Karen A.; Luckring, James M.; Carter, Melissa B.; Flamm, Jeffrey D.;

Disentangling the causal relationships between work-home interference and employee health.

PubMed

van Hooff, Madelon L M; Geurts, Sabine A E; Taris, Toon W; Kompier, Michiel A J; Dikkers, Josje S E; Houtman, Irene L D; van den Heuvel, Floor M M

2005-02-01

The present study was designed to investigate the causal relationships between (time- and strain-based) work-home interference and employee health. The effort-recovery theory provided the theoretical basis for this study. Two-phase longitudinal data (with a 1-year time lag) were gathered from 730 Dutch police officers to test the following hypotheses with structural equation modeling: (i) work-home interference predicts health deterioration, (ii) health complaints precede increased levels of such interference, and (iii) both processes operate. The relationship between stable and changed levels of work-home interference across time and their relationships with the course of health were tested with a group-by-time analysis of variance. Four subgroups were created that differed in starting point and the development of work-home interference across time. The normal causal model, in which strain-based (but not time-based) work-home interference was longitudinally related to increased health complaints 1 year later, fit the data well and significantly better than the reversed causal model. Although the reciprocal model also provided a good fit, it was less parsimonious than the normal causal model. In addition, both an increment in (strain-based) work-home interference across time and a long-lasting experience of high (strain-based) work-home interference were associated with a deterioration in health. It was concluded that (strain-based) work-home interference acts as a precursor of health impairment and that different patterns of (strain-based) work-home interference across time are related to different health courses. Particularly long-term experience of (strain-based) work-home interference seems responsible for an accumulation of health complaints.

78 FR 35173 - Physical Medicine Devices; Reclassification of Stair-Climbing Wheelchairs

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

.... Electromagnetic interference: The device may interfere with the operation of other electrical devices or be... electromagnetic compatibility testing as well as characterization of speed/acceleration, battery longevity, and... electrical safety and electromagnetic compatibility of the device. Performance testing must demonstrate...

Reduction of ground noise in the transmitter crowbar instrumentation system by the use of baluns and other noise rejection methods

NASA Technical Reports Server (NTRS)

Daeges, J.; Bhanji, A.

1987-01-01

Electrical noise interference in the transmitter crowbar monitoring instrumentation system creates false sensing of crowbar faults during a crowbar firing. One predominant source of noise interference is the conduction of currents in the instrumentation cable shields. Since these circulating ground noise currents produce noise that is similar to the crowbar fault sensing signals, such noise interference reduces the ability to determine true crowbar faults.

Pressure distributions from high Reynolds number transonic tests of an NACA 0012 airfoil in the Langley 0.3-meter transonic cryogenic tunnel

NASA Technical Reports Server (NTRS)

Ladson, Charles L.; Hill, Acquilla S.; Johnson, William G., Jr.

1987-01-01

Tests were conducted in the 2-D test section of the Langley 0.3-meter Transonic Cryogenic Tunnel on a NACA 0012 airfoil to obtain aerodynamic data as a part of the Advanced Technology Airfoil Test (ATAT) program. The test program covered a Mach number range of 0.30 to 0.82 and a Reynolds number range of 3.0 to 45.0 x 10 to the 6th power. The stagnation pressure was varied between 1.2 and 6.0 atmospheres and the stagnation temperature was varied between 300 K and 90 K to obtain these test conditions. Tabulated pressure distributions and integrated force and moment coefficients are presented as well as plots of the surface pressure distributions. The data are presented uncorrected for wall interference effects and without analysis.

Test results at transonic speeds on a contoured over-the-wing propfan model

NASA Technical Reports Server (NTRS)

Levin, Alan D.; Smeltzer, Donald B.; Smith, Ronald C.

1986-01-01

A semispan wing/body model with a powered highly loaded propeller has been tested to provide data on the propulsion installation drag of advanced propfan-powered aircraft. The model had a supercritical wing with a contoured over-the-wing nacelle. It was tested in the Ames Research Center's (ARC) 14-foot Transonic Wind Tunnel at a total pressure of 1 atm. The test was conducted at angles of attack from -0.5 to 4 deg at Mach numbers ranging from 0.6 to 0.8. The test objectives were to determine propeller performance, exhaust jet effects, propeller slipstream interference drag, and total powerplant installation drag. Test results indicated a total powerplant installation drag of 82 counts (0.0082) at a Mach number of 0.8 and a lift coefficient of 0.5, which is approximately 29 percent of a typical airplane cruise drag.

Wistar-Kyoto rats as an animal model of anxiety vulnerability: support for a hypervigilance hypothesis.

PubMed

McAuley, J D; Stewart, A L; Webber, E S; Cromwell, H C; Servatius, R J; Pang, K C H

2009-12-01

Inbred Wistar-Kyoto (WKY) rats have been proposed as a model of anxiety vulnerability as they display behavioral inhibition and a constellation of learning and reactivity abnormalities relative to outbred Sprague-Dawley (SD) rats. Together, the behaviors of the WKY rat suggest a hypervigilant state that may contribute to its anxiety vulnerability. To test this hypothesis, open-field behavior, acoustic startle, pre-pulse inhibition and timing behavior were assessed in WKY and Sprague-Dawley (SD) rats. Timing behavior was evaluated using a modified version of the peak-interval timing procedure. Training and testing of timing first occurred without audio-visual (AV) interference. Following this initial test, AV interference was included on some trials. Overall, WKY rats took much longer to leave the center of the arena, made fewer line crossings, and reared less, than did SD rats. WKY rats showed much greater startle responses to acoustic stimuli and significantly greater pre-pulse inhibition than did the SD rats. During timing conditions without AV interference, timing accuracy for both strains was similar; peak times for WKY and SD rats were not different. During interference conditions, however, the timing behavior of the two strains was very different. Whereas peak times for SD rats were similar between non-interference and interference conditions, peak times for WKY rats were shorter and response rates higher in interference conditions than in non-interference conditions. The enhanced acoustic startle response, greater prepulse inhibition and altered timing behavior with audio-visual interference supports a characterization of WKY strain as hypervigilant and provides further evidence for the use of the WKY strain as a model of anxiety vulnerability.

Unique Challenges Testing SDRs for Space

NASA Technical Reports Server (NTRS)

Chelmins, David; Downey, Joseph A.; Johnson, Sandra K.; Nappier, Jennifer M.

2013-01-01

This paper describes the approach used by the Space Communication and Navigation (SCaN) Testbed team to qualify three Software Defined Radios (SDR) for operation in space and the characterization of the platform to enable upgrades on-orbit. The three SDRs represent a significant portion of the new technologies being studied on board the SCAN Testbed, which is operating on an external truss on the International Space Station (ISS). The SCaN Testbed provides experimenters an opportunity to develop and demonstrate experimental waveforms and applications for communication, networking, and navigation concepts and advance the understanding of developing and operating SDRs in space. Qualifying a Software Defined Radio for the space environment requires additional consideration versus a hardware radio. Tests that incorporate characterization of the platform to provide information necessary for future waveforms, which might exercise extended capabilities of the hardware, are needed. The development life cycle for the radio follows the software development life cycle, where changes can be incorporated at various stages of development and test. It also enables flexibility to be added with minor additional effort. Although this provides tremendous advantages, managing the complexity inherent in a software implementation requires a testing beyond the traditional hardware radio test plan. Due to schedule and resource limitations and parallel development activities, the subsystem testing of the SDRs at the vendor sites was primarily limited to typical fixed transceiver type of testing. NASA s Glenn Research Center (GRC) was responsible for the integration and testing of the SDRs into the SCaN Testbed system and conducting the investigation of the SDR to advance the technology to be accepted by missions. This paper will describe the unique tests that were conducted at both the subsystem and system level, including environmental testing, and present results. For example, test waveforms were developed to measure the gain of the transmit system across the tunable frequency band. These were used during thermal vacuum testing to enable characterization of the integrated system in the wide operational temperature range of space. Receive power indicators were used for Electromagnetic Interference tests (EMI) to understand the platform s susceptibility to external interferers independent of the waveform. Additional approaches and lessons learned during the SCaN Testbed subsystem and system level testing will be discussed that may help future SDR integrators

Unique Challenges Testing SDRs for Space

NASA Technical Reports Server (NTRS)

Johnson, Sandra; Chelmins, David; Downey, Joseph; Nappier, Jennifer

2013-01-01

This paper describes the approach used by the Space Communication and Navigation (SCaN) Testbed team to qualify three Software Defined Radios (SDR) for operation in space and the characterization of the platform to enable upgrades on-orbit. The three SDRs represent a significant portion of the new technologies being studied on board the SCAN Testbed, which is operating on an external truss on the International Space Station (ISS). The SCaN Testbed provides experimenters an opportunity to develop and demonstrate experimental waveforms and applications for communication, networking, and navigation concepts and advance the understanding of developing and operating SDRs in space. Qualifying a Software Defined Radio for the space environment requires additional consideration versus a hardware radio. Tests that incorporate characterization of the platform to provide information necessary for future waveforms, which might exercise extended capabilities of the hardware, are needed. The development life cycle for the radio follows the software development life cycle, where changes can be incorporated at various stages of development and test. It also enables flexibility to be added with minor additional effort. Although this provides tremendous advantages, managing the complexity inherent in a software implementation requires a testing beyond the traditional hardware radio test plan. Due to schedule and resource limitations and parallel development activities, the subsystem testing of the SDRs at the vendor sites was primarily limited to typical fixed transceiver type of testing. NASA's Glenn Research Center (GRC) was responsible for the integration and testing of the SDRs into the SCaN Testbed system and conducting the investigation of the SDR to advance the technology to be accepted by missions. This paper will describe the unique tests that were conducted at both the subsystem and system level, including environmental testing, and present results. For example, test waveforms were developed to measure the gain of the transmit system across the tunable frequency band. These were used during thermal vacuum testing to enable characterization of the integrated system in the wide operational temperature range of space. Receive power indicators were used for Electromagnetic Interference tests (EMI) to understand the platform's susceptibility to external interferers independent of the waveform. Additional approaches and lessons learned during the SCaN Testbed subsystem and system level testing will be discussed that may help future SDR integrators.

Design, fabrication, and characterization of polymeric bioMEMS for the detection of feline immunodeficiency virus (FIV)

NASA Astrophysics Data System (ADS)

Cohen, Brian; Gadre, Anand; Kaloyeros, Alain E.

2007-02-01

This project comprises the development of a novel polymeric BioMEMS device capable of rapidly detecting FIV in a minimally invasive manner. FIV severely inhibits the infected feline from mounting an immune response, and causes susceptibility to other types of diseases. Vaccines against FIV do exist, but have some strong limitations to their effectiveness; so early detection is the best method to combat the spread of the disease. Current testing methods look for antibodies to the FIV protein p24 in feline blood using established Enzyme Linked ImmunoSorbent Assay (ELISA) protocols. The focus of this research is to design and construct a device that can detect antibodies to p24 in a salivary sample by non-intrusive electrochemical means. The device is constructed upon a silicon substrate with gold microelectrodes coated with polypyrrole (PPy), an electrically conducting and biocompatible polymer. In the current phase of the research, the PPy deposition process has been optimized with regards to film thickness, uniformity and conductivity. Microfluidic channels have been fabricated using SU-8, an epoxy based polymer that enables the test sample and other solutions to pass freely through the device. The PPy will be coated with anti-FIV p24 antibodies that can capture FIV p24 antigens present in a salivary sample. Future research will involve the analysis of PPy/antibody interaction and its effect on functionality. The capture of such antigens will interfere with a reduction-oxidation (redox) reaction in a subsequently added ionic solution. This interference will change the characteristic resistance of the solution yielding a qualitative test for the presence of the viral antigens in the sample and hence determining the occurrence of infection.

Interference removals on Pd, Ru and Au with ICP-QQQ-MS in PGE RM

NASA Astrophysics Data System (ADS)

Nadeem Hussain Bokhari, Syed; Meisel, Thomas; Walkner, Christoph

2015-04-01

Gold and platinum group elements (PGE) are essential industrial precious metals with high world demand due to their unique properties. Struggle for natural exploration of PGE is on great pace and recycling from industrial wastes, electronics and catalytic convertor is on the rise for PGE supply chain. Along with these developments it is becoming more challenging for analytical chemists to determine gold and PGE out of complex matrix which causes severe interferences. The current state of art is online analysis coupled with chromatographic separation of interferences. The ICP-QQQ-MS Agilent 8800 has the capability of using multi tunes and mass shifts. We aim to remove interferences on Pd+ (for direct and isotope dilution analysis) Au+ and Ru+ in lieu of chemical separations. YO+, SrOH+, ZnAr+, NiAr+, ZrO+, CuAr+, MoO+ , Ru+and Cd+ are expected interferences on Pd+ while Au+ is interfered by TaO+, HfOH+, GdAr+ and 102Ru+ ,104Ru+ by 102Pd+ ,104Pd+ etc. Initial test were performed on pure solutions of 1mg/l (interfering elements): 1 ng/l (Pd, Ru & Au) respectively. The outcomes of initial tests were applied on PGE reference material (RM) WMG-1 and SARM-7 (digested with Na2O2 sintering). The results obtained show that YO+, SrOH+ interfere (104Pd,105Pd), 104 Ru+ on (104Pd), ZnAr+ has slight interference on (104Pd and106Pd), ZrO+, NiAr+, CuAr+ interferences are negligible, MoO+ has severe interference on (108Pd, 110Pd) and that Cd+ has severe isobaric interference on (106Pd,108Pd, 110Pd). These interference have been removed by formation of Pd(NH3)3+complex. The TaO+, HfOH+ and GdAr+ interferences on Au+ are best removed by formation of Au(NH3)+ and Au(NH3)2+ complexes. 102Pd+,104Pd+interference on 102Ru+ ,104Ru+ can be removed by formation of Ru(NH3)4+ and RuO+ compounds. The results obtained comply with certified values of RM. The developed method is being tested on low concentration PGE reference materials. References: Sugiyama, N. " Removal of complex spectral interferences on noble metal isotopes." Agilent 8800 ICP-QQQ Application Handbook, 2014, 42-46.

Quantum interference in DNA bases probed by graphene nanoribbons

NASA Astrophysics Data System (ADS)

Jeong, Heejeong; Seul Kim, Han; Lee, Sung-Hoon; Lee, Dongho; Hoon Kim, Yong; Huh, Nam

2013-07-01

Based on first-principles nonequilibrium Green's function calculations, we demonstrate quantum interference (QI) effects on the tunneling conductance of deoxyribonucleic acid bases placed between zigzag graphene nanoribbon electrodes. With the analogy of QI in hydrocarbon ring structures, we hypothesize that QI can be well preserved in the π-π coupling between the carbon-based electrode and a single DNA base. We demonstrate indications of QI, such as destructively interfered anti-resonance or Fano-resonance, that affect the variation of tunneling conductance depending on the orientation of a base. We find that guanine, with a 10-fold higher transverse conductance, can be singled out from the other bases.

Not all performance validity tests are created equal: The role of recollection and familiarity in the Test of Memory Malingering and Word Memory Test.

PubMed

Eglit, Graham M L; Lynch, Julie K; McCaffrey, Robert J

2017-03-01

The Test of Memory Malingering (TOMM) and the Word Memory Test (WMT) are both performance validity tests (PVTs) that use a two-alternative forced-choice (2AFC) recognition memory format. Several studies have reported that these tests are susceptible to cognitive impairment and that the WMT is more susceptible than the TOMM. The current study explored components of recognition memory (i.e., conscious recollection and familiarity) underlying the TOMM and WMT to identify factors that make them susceptible and resilient to cognitive impairment. Fifty-four nonclinical undergraduate research participants were administered the TOMM and WMT while providing introspective judgments about their recognition memory using the remember/know/guess procedure. In addition, half of participants were administered dual-task interference, a manipulation intended to reduce recollection, during these tests, while the other half completed these tests without interference. Standard cutoffs on the TOMM and WMT were explored, as well as alternative cutoffs based on TOMM Trial 1 scores. The WMT was more impacted by dual-task interference than standard TOMM cutoff trials, while alternative TOMM cutoff trials were equally impacted by dual-task interference relative to the WMT. Dual-task interference reduced recollection on these tests, but spared familiarity. Standard TOMM trials and the WMT were relatively comparable on levels of recollection, but familiarity contributed more to the TOMM than to the WMT. Alternative TOMM trials possessed lower familiarity and recollection than standard TOMM trials and lower recollection than the WMT. Reduced recollection places examinees at risk of failing the TOMM and WMT, while familiarity contributes to the relative resilience of the standard TOMM. Future development of 2AFC recognition memory PVTs should attempt to maximize the contribution of familiarity to their completion.

Research on modeling and conduction disturbance simulation of secondary power system in a device

NASA Astrophysics Data System (ADS)

Ding, Xu; Yu, Zhi-Yong; Jin, Rui

2017-06-01

To find electromagnetic interference (EMI) and other problems in the secondary power supply system design quickly and effectively, simulations are carried out under the Saber simulation software platform. The DC/DC converter model with complete performance and electromagnetic characteristics is established by combining parametric modeling with Mast language. By using the method of macro modeling, the hall current sensor and power supply filter model are established respectively based on the function, schematic diagram of the components. Also the simulation of the component model and the whole secondary power supply system are carried out. The simulation results show that the proposed model satisfies the functional requirements of the system and has high accuracy. At the same time, due to the ripple characteristics in the DC/DC converter modeling, it can be used as a conducted interference model to simulate the power bus conducted emission CE102 project under the condition that the simulated load is full, which provides a useful reference for the electromagnetic interference suppression of the system.

Task 2 - Limits for High-Frequency Conducted Susceptibility Testing - CS114 (NRC-HQ-60-14-D-0015)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Richard Thomas; Ewing, Paul D.; Moses, Rebecca J.

2015-09-01

A principal focus of Task 2 under this project was for ORNL to evaluate the basis for susceptibility testing against high-frequency conducted interference and to establish recommendations to resolve concerns about the severity of test limits for the conducted susceptibility (CS) test, CS114, from MIL-STD-461. The primary concern about the test limit has been characterized by the EPRI EMI Working Group in the following terms: Demonstrating compliance with the CS114 test limits recommended in TR-102323 has proven to be problematic, even for components that have been tested to commercial standards and demonstrated proper operation in industrial applications [6]. Specifically, EPRImore » notes that the CS114 limits approved in regulatory documents are significantly higher than those invoked by the US military and similar commercial standards in the frequency range below 200 kHz. For this task, ORNL evaluated the original approach to establishing the test limit, EPRI technical findings from a review of the limit, and the regulatory basis through which the currently approved limits were accepted. Based on this analysis, strategies have been developed regarding changes to the CS114 limit that can resolve the technical concerns raised by the industry. Guided by the principles that reasonable assurance of safety must not be compromised but excessive conservatism should be reduced, recommendations on a suitable basis for a revised limit have been developed and can be incorporated into the planned Revision 2 of RG 1.180.« less

Quantum interference magnetoconductance of polycrystalline germanium films in the variable-range hopping regime

NASA Astrophysics Data System (ADS)

Li, Zhaoguo; Peng, Liping; Zhang, Jicheng; Li, Jia; Zeng, Yong; Zhan, Zhiqiang; Wu, Weidong

2018-06-01

Direct evidence of quantum interference magnetotransport in polycrystalline germanium films in the variable-range hopping (VRH) regime is reported. The temperature dependence of the conductivity of germanium films fulfilled the Mott VRH mechanism with the form of ? in the low-temperature regime (?). For the magnetotransport behaviour of our germanium films in the VRH regime, a crossover, from negative magnetoconductance at the low-field to positive magnetoconductance at the high-field, is observed while the zero-field conductivity is higher than the critical value (?). In the regime of ?, the magnetoconductance is positive and quadratic in the field for some germanium films. These features are in agreement with the VRH magnetotransport theory based on the quantum interference effect among random paths in the hopping process.

A new method of evaluating the side wall interference effect on airfoil angle of attack by suction from the side walls

NASA Technical Reports Server (NTRS)

Sawada, H.; Sakakibara, S.; Sato, M.; Kanda, H.; Karasawa, T.

1984-01-01

A quantitative evaluation method of the suction effect from a suction plate on side walls is explained. It is found from wind tunnel tests that the wall interference is basically described by the summation form of wall interferences in the case of two dimensional flow and the interference of side walls.

Determination of hydroxide and carbonate contents of alkaline electrolytes containing zinc

NASA Technical Reports Server (NTRS)

Otterson, D. A.

1975-01-01

A method to prevent zinc interference with the titration of OH- and CO3-2 ions in alkaline electrolytes with standard acid is presented. The Ba-EDTA complex was tested and shown to prevent zinc interference with acid-base titrations without introducing other types of interference. Theoretical considerations indicate that this method can be used to prevent interference by other metals.

Matter-wave diffraction approaching limits predicted by Feynman path integrals for multipath interference

NASA Astrophysics Data System (ADS)

Barnea, A. Ronny; Cheshnovsky, Ori; Even, Uzi

2018-02-01

Interference experiments have been paramount in our understanding of quantum mechanics and are frequently the basis of testing the superposition principle in the framework of quantum theory. In recent years, several studies have challenged the nature of wave-function interference from the perspective of Born's rule—namely, the manifestation of so-called high-order interference terms in a superposition generated by diffraction of the wave functions. Here we present an experimental test of multipath interference in the diffraction of metastable helium atoms, with large-number counting statistics, comparable to photon-based experiments. We use a variation of the original triple-slit experiment and accurate single-event counting techniques to provide a new experimental bound of 2.9 ×10-5 on the statistical deviation from the commonly approximated null third-order interference term in Born's rule for matter waves. Our value is on the order of the maximal contribution predicted for multipath trajectories by Feynman path integrals.

Space shuttle: Directional and lateral stability and interference effects of cruise engine location on a 0.015 scale space shuttle

NASA Technical Reports Server (NTRS)

Buchholz, R. E.

1972-01-01

The results are presented that were obtained from a wind tunnel tests to improve space shuttle booster baseline lateral-directional stability, control characteristics, and cruise engine location optimization. Tests were conducted in a 7 x 10-foot transonic wind tunnel. The model employed was a 0.015-scale replica of a space shuttle booster. The three major objectives of this test were to determine the following: (1) force, static stability, and control effectiveness characteristics for varying angles of positive and negative wing dihedral and various combinations of wing tip and centerline dorsal fins; (2) force and static stability characteristics of cruise engines location on the body below the high aerodynamic canard; and (3) control effectiveness for the low-mounted wing configuration. The wing dihedral study was conducted at a cruise Mach number of 0.40 and simulated altitude of 10,000 feet. Portions of the test were conducted to determine the control surfaces stability and control characteristics over the Mach number range of 0.4 to 1.2. The aerodynamic characteristics determined are based on a unit Reynolds number of approximately 2 million per foot. Boundary layer trip strips were employed to induce boundary layer transition.

Pain and Cognitive Function Among Older Adults Living in the Community

PubMed Central

van der Leeuw, Guusje; Eggermont, Laura H. P.; Shi, Ling; Milberg, William P.; Gross, Alden L.; Hausdorff, Jeffrey M.; Bean, Jonathan F.

2016-01-01

Background. Pain related to many age-related chronic conditions is a burdensome problem in elderly adults and may also interfere with cognitive functioning. The purpose of this study was to examine the cross-sectional relationship between measures of pain severity and pain interference and cognitive performance in community-living older adults. Methods. We studied 765 participants in the Maintenance of Balance Independent Living Intellect and Zest (MOBILIZE) Boston Study, a population-based study of persons aged 70 and older. Global pain severity and interference were measured using the Brief Pain Inventory subscales. The neuropsychological battery included measures of attentional capacity (Trail Making Test A, WORLD Test), executive function (Trail Making Test B and Delta, Clock-in-a-Box, Letter Fluency), memory (Hopkins Verbal Learning Test), and a global composite measure of cognitive function. Multivariable linear regression models were used to analyze the relationship between pain and cognitive functioning. Results. Elderly adults with more severe pain or more pain interference had poorer performance on memory tests and executive functioning compared to elders with none or less pain. Pain interference was also associated with impaired attentional capacity. Additional adjustment for chronic conditions, behaviors, and psychiatric medication resulted in attenuation of many of the observed associations. However, the association between pain interference and general cognitive function persisted. Conclusions. Our findings point to the need for further research to understand how chronic pain may contribute to decline in cognitive function and to determine strategies that may help in preventing or managing these potential consequences of pain on cognitive function in older adults. PMID:26433218

Prediction of quantum interference in molecular junctions using a parabolic diagram: Understanding the origin of Fano and anti- resonances

NASA Astrophysics Data System (ADS)

Nozaki, Daijiro; Avdoshenko, Stanislav M.; Sevinçli, Hâldun; Gutierrez, Rafael; Cuniberti, Gianaurelio

2013-03-01

Recently the interest in quantum interference (QI) phenomena in molecular devices (molecular junctions) has been growing due to the unique features observed in the transmission spectra. In order to design single molecular devices exploiting QI effects as desired, it is necessary to provide simple rules for predicting the appearance of QI effects such as anti-resonances or Fano line shapes and for controlling them. In this study, we derive a transmission function of a generic molecular junction with a side group (T-shaped molecular junction) using a minimal toy model. We developed a simple method to predict the appearance of quantum interference, Fano resonances or anti- resonances, and its position in the conductance spectrum by introducing a simple graphical representation (parabolic model). Using it we can easily visualize the relation between the key electronic parameters and the positions of normal resonant peaks and anti-resonant peaks induced by quantum interference in the conductance spectrum. We also demonstrate Fano and anti-resonance in T-shaped molecular junctions using a simple tight-binding model. This parabolic model enables one to infer on-site energies of T-shaped molecules and the coupling between side group and main conduction channel from transmission spectra.

NACA Transonic Wind-tunnel Test Sections

NASA Technical Reports Server (NTRS)

Wright, Ray H; Ward, Vernon G

1955-01-01

Report presents an approximate subsonic theory for the solid-blockage interference in circular wind tunnels with walls slotted in the direction of flow. This theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.

Test Results for Developing Revised LORAN-C Protection Criteria

DOT National Transportation Integrated Search

1985-11-01

This report presents the results obtained from a series of tests and related analyses studying the effect of harmful RF interference on LORAN-C receivers. The effects of interference in the 70 to 130 kHz band on typical LORAN-C receivers were assesse...

Validity, cut-points, and minimally important differences for two hot flash-related daily interference scales.

PubMed

Carpenter, Janet S; Bakoyannis, Giorgos; Otte, Julie L; Chen, Chen X; Rand, Kevin L; Woods, Nancy; Newton, Katherine; Joffe, Hadine; Manson, JoAnn E; Freeman, Ellen W; Guthrie, Katherine A

2017-08-01

To conduct psychometric analyses to condense the Hot Flash-Related Daily Interference Scale (HFRDIS) into a shorter form termed the Hot Flash Interference (HFI) scale; evaluate cut-points for both scales; and establish minimally important differences (MIDs) for both scales. We analyzed baseline and postrandomization patient-reported data pooled across three randomized trials aimed at reducing vasomotor symptoms (VMS) in 899 midlife women. Trials were conducted across five MsFLASH clinical sites between July 2009 and October 2012. We eliminated HFRDIS items based on experts' content validity ratings and confirmatory factor analysis, and evaluated cut-points and established MIDs by mapping HFRDIS and HFI to other measures. The three-item HFI (interference with sleep, mood, and concentration) demonstrated strong internal consistency (alphas of 0.830 and 0.856), showed good fit to the unidimensional "hot flash interference factor," and strong convergent validity with HFRDIS scores, diary VMS, and menopausal quality of life. For both scales, cut-points of mild (0-3.9), moderate (4-6.9), and severe (7-10) interference were associated with increasing diary VMS ratings, sleep, and anxiety. The average MID was 1.66 for the HFRDIS and 2.34 for the HFI. The HFI is a brief assessment of VMS interference and will be useful in busy clinics to standardize VMS assessment or in research studies where response burden may be an issue. The scale cut-points and MIDs should prove useful in targeting those most in need of treatment, monitoring treatment response, and interpreting existing and future research findings.

Electromagnetic interference of power conditioners for solar electric propulsion

NASA Technical Reports Server (NTRS)

Whittlesey, A. C.; Macie, T. W.

1973-01-01

Electrical, multikilowatt power conditioning (PC) equipment needed on board a spacecraft utilizing solar electric propulsion creates an electromagnetic environment that is potentially deterimental to the science, navigation, and radio communication hardware. Within the scope of the solar electric propulsion system technology program, three lightweight, 2.5-kW PCs were evaluated in terms of their electromagnetic characteristics. It was found that the levels of radiated and conducted interference exceeded the levels anticipated for a solar electric propulsion mission. These noise emissions, however, were the result of deficient interference design in these models, rather than a basic inability to control interference in this type of PC.

CW Interference Effects on High Data Rate Transmission Through the ACTS Wideband Channel

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Ngo, Duc H.; Tran, Quang K.; Tran, Diepchi T.; Yu, John; Kachmar, Brian A.; Svoboda, James S.

1996-01-01

Satellite communications channels are susceptible to various sources of interference. Wideband channels have a proportionally greater probability of receiving interference than narrowband channels. NASA's Advanced Communications Technology Satellite (ACTS) includes a 900 MHz bandwidth hardlimiting transponder which has provided an opportunity for the study of interference effects of wideband channels. A series of interference tests using two independent ACTS ground terminals measured the effects of continuous-wave (CW) uplink interference on the bit-error rate of a 220 Mbps digitally modulated carrier. These results indicate the susceptibility of high data rate transmissions to CW interference and are compared to results obtained with a laboratory hardware-based system simulation and a computer simulation.

Binaural Interference and the Effects of Age and Hearing Loss.

PubMed

Mussoi, Bruna S S; Bentler, Ruth A

2017-01-01

The existence of binaural interference, defined here as poorer speech recognition with both ears than with the better ear alone, is well documented. Studies have suggested that its prevalence may be higher in the elderly population. However, no study to date has explored binaural interference in groups of younger and older adults in conditions that favor binaural processing (i.e., in spatially separated noise). Also, the effects of hearing loss have not been studied. To examine binaural interference through speech perception tests, in groups of younger adults with normal hearing, older adults with normal hearing for their age, and older adults with hearing loss. A cross-sectional study. Thirty-three participants with symmetric thresholds were recruited from the University of Iowa community. Participants were grouped as follows: younger with normal hearing (18-28 yr, n = 12), older with normal hearing for their age (73-87 yr, n = 9), and older with hearing loss (78-94 yr, n = 12). Prior noise exposure was ruled out. The Connected Speech Test (CST) and Hearing in Noise Test (HINT) were administered to all participants bilaterally, and to each ear separately. Test materials were presented in the sound field with speech at 0° azimuth and the noise at 180°. The Dichotic Digits Test (DDT) was administered to all participants through earphones. Hearing aids were not used during testing. Group results were compared with repeated measures and one-way analysis of variances, as appropriate. Within-subject analyses using pre-established critical differences for each test were also performed. The HINT revealed no effect of condition (individual ear versus bilateral presentation) using group analysis, although within-subject analysis showed that 27% of the participants had binaural interference (18% had binaural advantage). On the CST, there was significant binaural advantage across all groups with group data analysis, as well as for 12% of the participants at each of the two signal-to-babble ratios (SBRs) tested. One participant had binaural interference at each SBR. Finally, on the DDT, a significant right-ear advantage was found with group data, and for at least some participants. Regarding age effects, more participants in the pooled elderly groups had binaural interference (33.3%) than in the younger group (16.7%), on the HINT. The presence of hearing loss yielded overall lower scores, but none of the comparisons between bilateral and unilateral performance were affected by hearing loss. Results of within-subject analyses on the HINT agree with previous findings of binaural interference in ≥17% of listeners. Across all groups, a significant right-ear advantage was also seen on the DDT. HINT results support the notion that the prevalence of binaural interference is likely higher in the elderly population. Hearing loss, however, did not affect the differences between bilateral and better unilateral scores. The possibility of binaural interference should be considered when fitting hearing aids to listeners with symmetric hearing loss. Comparing bilateral to unilateral (unaided) performance on tests such as the HINT may provide the clinician with objective data to support subjective preference for one hearing aid as opposed to two. American Academy of Audiology

Tunable strength saddle-point contacts impact on quantum rings transmission

NASA Astrophysics Data System (ADS)

González, J. J.; Diago-Cisneros, L.

2016-09-01

A particular subject of investigation is the role of several sadle-point contact (QPC) parameters on the scattering properties of an Aharonov-Bohm-Aharonov-Casher quantum ring (QR) under Rashba-type spin orbit interaction. We discuss the interplay of the conductance with the confinement strengths and height of the QPC, which yields new and tunable harmonic and non-harmonics patterns, while one manipulates these constriction parameters. This phenomenology may be of utility to implement a novel way to modulate spin interference effects in semiconducting QRs, providing an appealing test-platform for spintronics applications.

Serum sample containing endogenous antibodies interfering with multiple hormone immunoassays. Laboratory strategies to detect interference.

PubMed

García-González, Elena; Aramendía, Maite; Álvarez-Ballano, Diego; Trincado, Pablo; Rello, Luis

2016-04-01

Endogenous antibodies (EA) may interfere with immunoassays, causing erroneous results for hormone analyses. As (in most cases) this interference arises from the assay format and most immunoassays, even from different manufacturers, are constructed in a similar way, it is possible for a single type of EA to interfere with different immunoassays. Here we describe the case of a patient whose serum sample contains EA that interfere several hormones tests. We also discuss the strategies deployed to detect interference. Over a period of four years, a 30-year-old man was subjected to a plethora of laboratory and imaging diagnostic procedures as a consequence of elevated hormone results, mainly of pituitary origin, which did not correlate with the overall clinical picture. Once analytical interference was suspected, the best laboratory approaches to investigate it were sample reanalysis on an alternative platform and sample incubation with antibody blocking tubes. Construction of an in-house 'nonsense' sandwich assay was also a valuable strategy to confirm interference. In contrast, serial sample dilutions were of no value in our case, while polyethylene glycol (PEG) precipitation gave inconclusive results, probably due to the use of inappropriate PEG concentrations for several of the tests assayed. Clinicians and laboratorians must be aware of the drawbacks of immunometric assays, and alert to the possibility of EA interference when results do not fit the clinical pattern.

Association between executive function and outcome measure of treatment in therapeutic community among cocaine dependent individuals.

PubMed

Vergara-Moragues, Esperanza; Verdejo-García, Antonio; Lozano, Oscar M; Santiago-Ramajo, Sandra; González-Saiz, Francisco; Betanzos Espinosa, Patricia; Pérez García, Miguel

2017-07-01

The aim of this study was to examine the association between baseline executive functioning and outcome measure of treatment in 226 cocaine dependent individuals who initiated treatment in therapeutic communities TCs. The study was conducted across six TCs located in the region of Andalusia (southern Spain). Neuropsychological testing included tests of working memory, reasoning, inhibition, switching, attention interference and decision making. The outcome measures were type of discharge (treatment dropout vs. therapeutic discharge) and clinical impression of the TC outcome (clinically significant vs. non-significant changes). In the present study a prospective comparative design was used. We found significant performance differences on selective executive components which account for the type of discharge: treatment quitters had poorer attention response inhibition and attention switching than non-quitters, and the individuals who failed to achieve therapeutic objectives had poorer attention interference and inhibitory control than compliers. No significant differences were found between the outcome measure and the neuropsychological performance score on the other tasks. The results provide important information about the impact of executive components on in-treatment follow-up outcomes among dependence disorders in TC. Copyright © 2017 Elsevier Inc. All rights reserved.

A Novel Attitude Determination System Aided by Polarization Sensor

PubMed Central

Zhi, Wei; Chu, Jinkui; Li, Jinshan; Wang, Yinlong

2018-01-01

This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF) with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV) flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle. PMID:29315256

Hexavalent Chrome Free Coatings for Electronics Electromagnetic Interference (EMI) Shielding Effectiveness (SE) Interim Test Report

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2015-01-01

Test specimen configuration was provided by Parker Chomerics. The EMI gasket used in this project was Cho-Seal 6503E. Black oxide alloy steel socket head bolts were used to hold the plates together. Non-conductive spacers were used to control the amount of compression on the gaskets. The following test fixture specifications were provided by Parker Chomerics. The CHO-TP09 test plate sets selected for this project consist of two aluminum plates manufactured to the specifications detailed in CHO­-TP09. The first plate, referred to as the test frame, is illustrated in Figure 1. The test frame is designed with a cutout in the center and two alternating bolt patterns. One pattern is used to bolt the test frame to the corresponding test cover plate (Figure 2), forming a test plate set. The second pattern accepts the hardware used to mount the fully assembled test plate set to the main adapter plate (Figure 3).

Analytical Work in Support of the Design and Operation of Two Dimensional Self Streamlining Test Sections

NASA Technical Reports Server (NTRS)

Judd, M.; Wolf, S. W. D.; Goodyer, M. J.

1976-01-01

A method has been developed for accurately computing the imaginary flow fields outside a flexible walled test section, applicable to lifting and non-lifting models. The tolerances in the setting of the flexible walls introduce only small levels of aerodynamic interference at the model. While it is not possible to apply corrections for the interference effects, they may be reduced by improving the setting accuracy of the portions of wall immediately above and below the model. Interference effects of the truncation of the length of the streamlined portion of a test section are brought to an acceptably small level by the use of a suitably long test section with the model placed centrally.

Automatic Radiated Susceptibility Test System for Payload Equipment

NASA Technical Reports Server (NTRS)

Ngo, Hoai T.; Sturman, John C.; Sargent, Noel B.

1995-01-01

An automatic radiated susceptibility test system (ARSTS) was developed for NASA Lewis Research Center's Electro-magnetic Interference laboratory. According to MSFC-SPEC 521B, any electrical or electronic equipment that will be transported by the spacelab and space shuttle must be tested for susceptibility to electromagnetic interference. This state-of-the-art automatic test system performs necessary calculations; analyzes, processes, and records a great quantity of measured data; and monitors the equipment being tested in real-time and with minimal user intervention. ARSTS reduces costly test time, increases test accuracy, and provides reliable test results.

Release from proactive interference in rat spatial working memory.

PubMed

Roberts, William A; MacDonald, Hayden; Brown, Lyn; Macpherson, Krista

2017-09-01

A three-phase procedure was used to produce proactive interference (PI) in one trial on an eight-arm radial maze. Rats were forced to enter four arms for reward on an initial interference phase, to then enter the four remaining arms on a target phase, and to then choose among all eight arms on a retention test, with only the arms not visited in the target phase containing reward. Control trials involved only the target phase and the retention test. Lower accuracy was found on PI trials than on control trials, but performance on PI trials significantly exceeded chance, showing some retention of target memories. Changes in temporal and reward variables between the interference, target, and retention test phases showed release from PI, but changes in context and pattern of arm entry did not. It is suggested that the release from PI paradigm can be used to understand spatial memory encoding in rats and other species.

Direct Validation of the Wall Interference Correction System of the Ames 11-Foot Transonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert; Boone, Alan R.

2003-01-01

Data from the test of a large semispan model was used to perform a direct validation of a wall interference correction system for a transonic slotted wall wind tunnel. At first, different sets of uncorrected aerodynamic coefficients were generated by physically changing the boundary condition of the test section walls. Then, wall interference corrections were computed and applied to all data points. Finally, an interpolation of the corrected aerodynamic coefficients was performed. This interpolation made sure that the corrected Mach number of a given run would be constant. Overall, the agreement between corresponding interpolated lift, drag, and pitching moment coefficient sets was very good. Buoyancy corrections were also investigated. These studies showed that the accuracy goal of one drag count may only be achieved if reliable estimates of the wall interference induced buoyancy correction are available during a test.

Third Generation Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Smith, Laura J.; Williams, Reuben A.; Salud, Maria Theresa P.

2005-01-01

Radiated emissions in aircraft communication and navigation bands are measured from third generation (3G) wireless mobile phones. The two wireless technologies considered are the latest available to general consumers in the US. The measurements are conducted using reverberation chambers. The results are compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft. Using existing interference path loss data and receivers interference threshold, a risk assessment is performed for several aircraft communication and navigation radio systems. In addition, cumulative interference effects of multiple similar devices are conservatively estimated or bounded. The effects are computed by summing the interference power from individual devices that is scaled according to the interference path loss at its location.

Role of inter-tube coupling and quantum interference on electrical transport in carbon nanotube junctions

NASA Astrophysics Data System (ADS)

Tripathy, Srijeet; Bhattacharyya, Tarun Kanti

2016-09-01

Due to excellent transport properties, Carbon nanotubes (CNTs) show a lot of promise in sensor and interconnect technology. However, recent studies indicate that the conductance in CNT/CNT junctions are strongly affected by the morphology and orientation between the tubes. For proper utilization of such junctions in the development of CNT based technology, it is essential to study the electronic properties of such junctions. This work presents a theoretical study of the electrical transport properties of metallic Carbon nanotube homo-junctions. The study focuses on discerning the role of inter-tube interactions, quantum interference and scattering on the transport properties on junctions between identical tubes. The electronic structure and transport calculations are conducted with an Extended Hückel Theory-Non Equilibrium Green's Function based model. The calculations indicate conductance to be varying with a changing crossing angle, with maximum conductance corresponding to lattice registry, i.e. parallel configuration between the two tubes. Further calculations for such parallel configurations indicate onset of short and long range oscillations in conductance with respect to changing overlap length. These oscillations are attributed to inter-tube coupling effects owing to changing π orbital overlap, carrier scattering and quantum interference of the incident, transmitted and reflected waves at the inter-tube junction.

Resolution of common dietary sugars from probe sugars for test of intestinal permeability using capillary column gas chromatography.

PubMed

Farhadi, Ashkan; Keshavarzian, Ali; Fields, Jeremy Z; Sheikh, Maliha; Banan, Ali

2006-05-19

The most widely accepted method for the evaluation of intestinal barrier integrity is the measurement of the permeation of sugar probes following an oral test dose of sugars. The most-widely used sugar probes are sucrose, lactulose, mannitol and sucralose. Measuring these sugars using a sensitive gas chromatographic (GC) method, we noticed interference on the area of the lactulose and mannitol peaks. We tested different sugars to detect the possible makeup of these interferences and finally detected that the lactose interferes with lactulose peak and fructose interferes with mannitol peak. On further developing of our method, we were able to reasonably separate these peaks using different columns and condition for our assay. Sample preparation was rapid and simple and included adding internal standard sugars, derivitization and silylation. We used two chromatographic methods. In the first method we used Megabore column and had a run time of 34 min. This resulted in partial separation of the peaks. In the second method we used thin capillary column and was able to reasonably separate the lactose and lactulose peaks and the mannitol and fructose peaks with run time of 22 min. The sugar probes including mannitol, sucrose, lactulose, sucralose, fructose and lactose were detected precisely, without interference. The assay was linear between lactulose concentrations of 0.5 and 40 g/L (r(2)=1.000, P<0.0001) and mannitol concentrations of 0.01 and 40 g/L (r(2)=1.000). The sensitivity of this method remained high using new column and assay condition. The minimum detectable concentration calculated for both methods was 0.5 mg/L for lactulose and 1 mg/L for mannitol. This is the first report of interference of commonly used sugars with test of intestinal permeability. These sugars are found in most of fruits and dairy products and could easily interfere with the result of permeability tests. Our new GC assay of urine sugar probes permits the simultaneous quantitation of sucralose, sucrose, mannitol and lactulose, without interference with lactose and fructose. This assay is a rapid, simple, sensitive and reproducible method to accurately measure intestinal permeability.

The effect of electromagnetic interference from mobile communication on the performance of intensive care ventilators.

PubMed

Jones, R P; Conway, D H

2005-08-01

Electromagnetic interference produced by wireless communication can affect medical devices and hospital policies exist to address this risk. During the transfer of ventilated patients, these policies may be compromised by essential communication between base and receiving hospitals. Local wireless networks (e.g. Bluetooth) may reduce the 'spaghetti syndrome' of wires and cables seen on intensive care units, but also generate electromagnetic interference. The aim of this study was to investigate these effects on displayed and actual ventilator performance. Five ventilators were tested: Drager Oxylog 2000, BREAS LTV-1000, Respironics BiPAP VISION, Puritan Bennett 7200 and 840. Electromagnetic interference was generated by three devices: Simoco 8020 radio handset, Nokia 7210 and Nokia 6230 mobile phone, Nokia 6230 communicating via Bluetooth with a Palm Tungsten T Personal Digital Assistant. We followed the American National Standard Recommended Practice for On-Site, Ad Hoc Testing (ANSI C63) for electromagnetic interference. We used a ventilator tester, to simulate healthy adult lungs and measure ventilator performance. The communication device under test was moved in towards each ventilator from a distance of 1 m in six axes. Alarms or error codes on the ventilator were recorded, as was ventilator performance. All ventilators tested, except for the Respironics VISION, showed a display error when subjected to electromagnetic interference from the Nokia phones and Simoco radio. Ventilator performance was only affected by the radio which caused the Puritan Bennett 840 to stop functioning completely. The transfer ventilators' performance were not affected by radio or mobile phone, although the mobile phone did trigger a low-power alarm. Effects on intensive care ventilators included display reset, with the ventilator restoring normal display function within 2 s, and low-power/low-pressure alarms. Bluetooth transmission had no effect on the function of all the ventilators tested. In a clinical setting, high-power-output devices such as a two-way radio may cause significant interference in ventilator function. Medium-power-output devices such as mobile phones may cause minor alarm triggers. Low-power-output devices such as Bluetooth appear to cause no interference with ventilator function.

The Contextual Interference Effect in Applied Settings

ERIC Educational Resources Information Center

Barreiros, Joao; Figueiredo, Teresa; Godinho, Mario

2007-01-01

This paper analyses the research literature that approaches the contextual interference effect in applied settings. In contrast to the laboratory settings, in which high interference conditions depress acquisition and promote learning evaluated in retention and transfer tests, in applied settings most of the studies (60%) fail to observe positive…

The dual effect of context on memory of related and unrelated themes: discrimination at encoding and cue at retrieval.

PubMed

Levy-Gigi, Einat; Vakil, Eli

2012-01-01

The influence of contextual factors on encoding and retrieval in recognition memory was investigated using a retroactive interference paradigm. Participants were randomly assigned to four context conditions constructed by manipulating types of presentation modality (pictures vs words) for study, interference, and test stages, respectively (ABA, ABB, AAA, & AAB). In Experiment 1 we presented unrelated items in the study and interference stages, while in Experiment 2 each stage contained items from the same semantic category. The results demonstrate a dual role for context in memory processes-at encoding as well as at retrieval. In Experiment 1 there is a hierarchical order between the four context conditions, depending on both target-test and target-interference contextual similarity. Adding a categorical context in Experiment 2 helped to specify each list and therefore better distinguish between target and interferer information, and in some conditions compensated for their perceptual similarity.

Single- and dual-carrier microwave noise abatement in the deep space network. [microwave antennas

NASA Technical Reports Server (NTRS)

Bathker, D. A.; Brown, D. W.; Petty, S. M.

1975-01-01

The NASA/JPL Deep Space Network (DSN) microwave ground antenna systems are presented which simultaneously uplink very high power S-band signals while receiving very low level S- and X-band downlinks. Tertiary mechanisms associated with elements give rise to self-interference in the forms of broadband noise burst and coherent intermodulation products. A long-term program to reduce or eliminate both forms of interference is described in detail. Two DSN antennas were subjected to extensive interference testing and practical cleanup program; the initial performance, modification details, and final performance achieved at several planned stages are discussed. Test equipment and field procedures found useful in locating interference sources are discussed. Practices deemed necessary for interference-free operations in the DSN are described. Much of the specific information given is expected to be easily generalized for application in a variety of similar installations. Recommendations for future investigations and individual element design are given.

A dedicated system for topographical working memory: evidence from domain-specific interference tests.

PubMed

Piccardi, L; Nori, R; Boccia, M; Barbetti, S; Verde, P; Guariglia, C; Ferlazzo, F

2015-08-01

In the present study, we used single- and dual-task conditions to investigate the nature of topographical working memory to better understand what type of task can hamper performance during navigation. During dual-task conditions, we considered four different sources of interference: motor (M), spatial motor (SM), verbal (i.e. articulatory suppression AS) and spatial environmental (SE). In order to assess the nature of topographical working memory, we used the Walking Corsi Test, asking the participants to perform two tasks simultaneously (M, SM, AS and SE). Our results showed that only spatial-environmental interference hampers the execution of a topographical working memory task, suggesting a task-domain-specific effect. We also found general gender differences in the topographical working memory capabilities: men were more proficient than women, regardless of the type of interferences. However, like men, women performed worse when a spatial-environmental interference was present.

Factitious Graves' Disease Due to Biotin Immunoassay Interference-A Case and Review of the Literature.

PubMed

Elston, Marianne S; Sehgal, Shekhar; Du Toit, Stephen; Yarndley, Tania; Conaglen, John V

2016-09-01

Biotin (vitamin B7) is an essential co-factor for four carboxylases involved in fatty acid metabolism, leucine degradation, and gluconeogenesis. The recommended daily intake (RDI) of biotin is approximately 30 μg per day. Low-moderate dose biotin is a common component of multivitamin preparations, and high-dose biotin (10 000 times RDI) has been reported to improve clinical outcomes and quality of life in patients with progressive multiple sclerosis. Biotin is also a component of immunoassays, and supplementation may cause interference in both thyroid and non-thyroid immunoassays. To assess whether biotin ingestion caused abnormal thyroid function tests (TFTs) in a patient through assay interference. We report a patient with biotin-associated abnormal TFTs and a systematic review of the literature. A tertiary endocrine service in Hamilton, New Zealand. The patient had markedly abnormal TFTs that did not match the clinical context. After biotin cessation, TFTs normalized far more rapidly than possible given the half-life of T4, consistent with assay interference by biotin. Multiple other analytes also tested abnormal in the presence of biotin. Biotin ingested in moderate to high doses can cause immunoassay interference. Depending on the assay format, biotin interference can result in either falsely high or low values. Interference is not limited to thyroid tests and has the potential to affect a wide range of analytes. It is important for clinicians to be aware of this interaction to prevent misdiagnosis and inappropriate treatment.

A harmonic pulse testing method for leakage detection in deep subsurface storage formations

NASA Astrophysics Data System (ADS)

Sun, Alexander Y.; Lu, Jiemin; Hovorka, Susan

2015-06-01

Detection of leakage in deep geologic storage formations (e.g., carbon sequestration sites) is a challenging problem. This study investigates an easy-to-implement frequency domain leakage detection technology based on harmonic pulse testing (HPT). Unlike conventional constant-rate pressure interference tests, HPT stimulates a reservoir using periodic injection rates. The fundamental principle underlying HPT-based leakage detection is that leakage modifies a storage system's frequency response function, thus providing clues of system malfunction. During operations, routine HPTs can be conducted at multiple pulsing frequencies to obtain experimental frequency response functions, using which the possible time-lapse changes are examined. In this work, a set of analytical frequency response solutions is derived for predicting system responses with and without leaks for single-phase flow systems. Sensitivity studies show that HPT can effectively reveal the presence of leaks. A search procedure is then prescribed for locating the actual leaks using amplitude and phase information obtained from HPT, and the resulting optimization problem is solved using the genetic algorithm. For multiphase flows, the applicability of HPT-based leakage detection procedure is exemplified numerically using a carbon sequestration problem. Results show that the detection procedure is applicable if the average reservoir conditions in the testing zone stay relatively constant during the tests, which is a working assumption under many other interpretation methods for pressure interference tests. HPT is a cost-effective tool that only requires periodic modification of the nominal injection rate. Thus it can be incorporated into existing monitoring plans with little additional investment.

THE IDENTIFICATION OF ALGAE WHICH INTERFERE WITH THE DETECTION OF GIARDIA AND CRYPTOSPORIDIUM AND A METHOD FOR ALLEVIATING THIS INTERFERENCE

EPA Science Inventory

Fifty-four algal species were tested for cross-reaction in the American Society for Testing and Materials Giardia/Cryptosporidium indirect immunofluorescence assay, and 24 showed some degree of fluorescence. Two species, Navicula minima and Synechococcus elongatus, exhibited a b...

PNTAB view : minimum criteria for testing/evaluation of interference potential of high power terrestrial transmitters in repurposed radio bands.

DOT National Transportation Integrated Search

2017-03-30

Brief, 6-point set of guidelines that describe how to test the interference potential of high power terrestrial transmitters in repurposed radio bands. Presented at Global Positioning System Adjacent Band Compatibility Assessment Workshop VI, 03/30/2...

Interference of Wing and Fuselage from Tests of 209 Combinations in the NACA Variable-Density Tunnel

NASA Technical Reports Server (NTRS)

Jacobs, Eastman N; Ward, Kenneth E

1936-01-01

This report presents the results of tests of 209 simple wing-fuselage combinations made in the NACA variable-density wind tunnel to provide information regarding the effects of aerodynamic interference between wings and fuselages at a large value of Reynolds number.

Individual Differences in Digit Span, Susceptibility to Proactive Interference, and Aptitude/Achievement Test Scores.

ERIC Educational Resources Information Center

Dempster, Frank N.; Cooney, John B.

1982-01-01

Individual differences in digit span, susceptibility to proactive interference, and various aptitude/achievement test scores were investigated in two experiments with college students. Results indicated that digit span was strongly correlated with aptitude/achievement scores, but did not indicate that susceptibility to proactive interference…

Torsional stability of interference screws derived from bovine bone - a biomechanical study

PubMed Central

2010-01-01

Background In the present biomechanical study, the torsional stability of different interference screws, made of bovine bone, was tested. Interference screws derived from bovine bone are a possible biological alternative to conventional metallic or bioabsorbable polymer interference screws. Methods In the first part of the study we compared the torsional stability of self-made 8 mm Interference screws (BC) and a commercial 8 mm interference screw (Tutofix®). Furthermore, we compared the torsional strength of BC screws with different diameters. For screwing in, a hexagon head and an octagon head were tested. Maximum breaking torques in polymethyl methacrylate resin were recorded by means of an electronic torque screw driver. In the second part of the study the tibial part of a bone-patellar tendon-bone graft was fixed in porcine test specimens using an 8 mm BC screw and the maximum insertion torques were recorded. Each interference screw type was tested 5 times. Results There was no statistically significant difference between the different 8 mm interference screws (p = 0.121). Pairwise comparisons did not reveal statistically significant differences, either. It was demonstrated for the BC screws, that a larger screw diameter significantly leads to higher torsional stability (p = 9.779 × 10-5). Pairwise comparisons showed a significantly lower torsional stability for the 7 mm BC screw than for the 8 mm BC screw (p = 0.0079) and the 9 mm BC screw (p = 0.0079). Statistically significant differences between the 8 mm and the 9 mm BC screw could not be found (p = 0.15). During screwing into the tibial graft channel of the porcine specimens, insertion torques between 0.5 Nm and 3.2 Nm were recorded. In one case the hexagon head of a BC screw broke off during the last turn. Conclusions The BC screws show comparable torsional stability to Tutofix® interference screws. As expected the torsional strength of the screws increases significantly with the diameter. The safety and in vivo performance of products derived from xenogeneic bone should be the focus of further investigations. PMID:20433761

The Real-Time Wall Interference Correction System of the NASA Ames 12-Foot Pressure Wind Tunnel

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert

1998-01-01

An improved version of the Wall Signature Method was developed to compute wall interference effects in three-dimensional subsonic wind tunnel testing of aircraft models in real-time. The method may be applied to a full-span or a semispan model. A simplified singularity representation of the aircraft model is used. Fuselage, support system, propulsion simulator, and separation wake volume blockage effects are represented by point sources and sinks. Lifting effects are represented by semi-infinite line doublets. The singularity representation of the test article is combined with the measurement of wind tunnel test reference conditions, wall pressure, lift force, thrust force, pitching moment, rolling moment, and pre-computed solutions of the subsonic potential equation to determine first order wall interference corrections. Second order wall interference corrections for pitching and rolling moment coefficient are also determined. A new procedure is presented that estimates a rolling moment coefficient correction for wings with non-symmetric lift distribution. Experimental data obtained during the calibration of the Ames Bipod model support system and during tests of two semispan models mounted on an image plane in the NASA Ames 12 ft. Pressure Wind Tunnel are used to demonstrate the application of the wall interference correction method.

Catheter ablation as a treatment of atrioventricular block.

PubMed

Tuohy, Stephen; Saliba, Walid; Pai, Manjunath; Tchou, Patrick

2018-01-01

Symptomatic second-degree atrioventricular (AV) block is typically treated by implantation of a pacemaker. An otherwise healthy AV conduction system can nevertheless develop AV block due to interference from junctional extrasystoles. When present with a high burden, these can produce debilitating symptoms from AV block despite an underlying normal AV node and His-Purkinje system properties. The purpose of this study was to describe a catheter ablation approach for alleviating symptomatic AV block due to a ventricular nodal pathway interfering with AV conduction. Common clinical monitoring techniques such as Holter and event recorders were used. Standard electrophysiological study techniques using multipolar recording and ablation catheters were utilized during procedures. A 55-year-old woman presented with highly symptomatic, high-burden second-degree AV block due to concealed and manifest junctional premature beats. Electrophysiological characteristics indicated interference of AV conduction due to a concealed ventricular nodal pathway as the cause of the AV block. The patient's AV nodal and His-Purkinje system conduction characteristics were otherwise normal. Radiofrequency catheter ablation of the pathway was successful in restoring normal AV conduction and eliminating her clinical symptoms. Pathways inserting into the AV junction can interfere with AV conduction. When present at a high burden, this type of AV block can be highly symptomatic. Catheter ablation techniques can be used to alleviate this type of AV block and restore normal AV conduction. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Development and evaluation of the PI-G: a three-scale measure based on the German translation of the PROMIS ® pain interference item bank.

PubMed

Farin, Erik; Nagl, Michaela; Gramm, Lukas; Heyduck, Katja; Glattacker, Manuela

2014-05-01

Study aim was to translate the PROMIS(®) pain interference (PI) item bank (41 items) into German, test its psychometric properties in patients with chronic low back pain and develop static subforms. We surveyed N = 262 patients undergoing rehabilitation who were asked to fill out questionnaires at the beginning and 2 weeks after the end of rehabilitation, applying the Oswestry Disability Index (ODI) and Pain Disability Index (PDI) in addition to the PROMIS(®) PI items. For psychometric testing, a 1-parameter item response theory (IRT) model was used. Exploratory and confirmatory factor analyses as well as reliability and construct validity analyses were conducted. The assumptions regarding IRT scaling of the translated PROMIS(®) PI item bank as a whole were not confirmed. However, we succeeded in devising three static subforms (PI-G scales: PI mental 13 items, PI functional 11 items, PI physical 4 items), revealing good psychometric properties. The PI-G scales in their static form can be recommended for use in German-speaking countries. Their strengths versus the ODI and PDI are that pain interference is assessed in a differentiated manner and that several psychometric values are somewhat better than those associated with the ODI and PDI (distribution properties, IRT model fit, reliability). To develop an IRT-scaled item bank of the German translations of the PROMIS(®) PI items, it would be useful to have additional studies (e.g., with larger sample sizes and using a 2-parameter IRT model).

Use of the Ames Check Standard Model for the Validation of Wall Interference Corrections

NASA Technical Reports Server (NTRS)

Ulbrich, N.; Amaya, M.; Flach, R.

2018-01-01

The new check standard model of the NASA Ames 11-ft Transonic Wind Tunnel was chosen for a future validation of the facility's wall interference correction system. The chosen validation approach takes advantage of the fact that test conditions experienced by a large model in the slotted part of the tunnel's test section will change significantly if a subset of the slots is temporarily sealed. Therefore, the model's aerodynamic coefficients have to be recorded, corrected, and compared for two different test section configurations in order to perform the validation. Test section configurations with highly accurate Mach number and dynamic pressure calibrations were selected for the validation. First, the model is tested with all test section slots in open configuration while keeping the model's center of rotation on the tunnel centerline. In the next step, slots on the test section floor are sealed and the model is moved to a new center of rotation that is 33 inches below the tunnel centerline. Then, the original angle of attack sweeps are repeated. Afterwards, wall interference corrections are applied to both test data sets and response surface models of the resulting aerodynamic coefficients in interference-free flow are generated. Finally, the response surface models are used to predict the aerodynamic coefficients for a family of angles of attack while keeping dynamic pressure, Mach number, and Reynolds number constant. The validation is considered successful if the corrected aerodynamic coefficients obtained from the related response surface model pair show good agreement. Residual differences between the corrected coefficient sets will be analyzed as well because they are an indicator of the overall accuracy of the facility's wall interference correction process.

Effect of occlusal interference on habitual activity of human masseter.

PubMed

Michelotti, A; Farella, M; Gallo, L M; Veltri, A; Palla, S; Martina, R

2005-07-01

It has been suggested that occlusal interference may increase habitual activity in the jaw muscles and may lead to temporomandibular disorders (TMD). We tested these hypotheses by means of a double-blind randomized crossover experiment carried out on 11 young healthy females. Strips of gold foil were glued either on a selected occlusal contact area (active interference) or on the vestibular surface of the same tooth (dummy interference) and left for 8 days each. Electromyographic masseter activity was recorded in the natural environment by portable recorders under interference-free, dummy-interference, and active-interference conditions. The active occlusal interference caused a significant reduction in the number of activity periods per hour and in their mean amplitude. The EMG activity did not change significantly during the dummy-interference condition. None of the subjects developed signs and/or symptoms of TMD throughout the whole study, and most of them adapted fairly well to the occlusal disturbance.

Pain and Cognitive Function Among Older Adults Living in the Community.

PubMed

van der Leeuw, Guusje; Eggermont, Laura H P; Shi, Ling; Milberg, William P; Gross, Alden L; Hausdorff, Jeffrey M; Bean, Jonathan F; Leveille, Suzanne G

2016-03-01

Pain related to many age-related chronic conditions is a burdensome problem in elderly adults and may also interfere with cognitive functioning. The purpose of this study was to examine the cross-sectional relationship between measures of pain severity and pain interference and cognitive performance in community-living older adults. We studied 765 participants in the Maintenance of Balance Independent Living Intellect and Zest (MOBILIZE) Boston Study, a population-based study of persons aged 70 and older. Global pain severity and interference were measured using the Brief Pain Inventory subscales. The neuropsychological battery included measures of attentional capacity (Trail Making Test A, WORLD Test), executive function (Trail Making Test B and Delta, Clock-in-a-Box, Letter Fluency), memory (Hopkins Verbal Learning Test), and a global composite measure of cognitive function. Multivariable linear regression models were used to analyze the relationship between pain and cognitive functioning. Elderly adults with more severe pain or more pain interference had poorer performance on memory tests and executive functioning compared to elders with none or less pain. Pain interference was also associated with impaired attentional capacity. Additional adjustment for chronic conditions, behaviors, and psychiatric medication resulted in attenuation of many of the observed associations. However, the association between pain interference and general cognitive function persisted. Our findings point to the need for further research to understand how chronic pain may contribute to decline in cognitive function and to determine strategies that may help in preventing or managing these potential consequences of pain on cognitive function in older adults. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

28 CFR 541.13 - Prohibited acts and disciplinary severity scale.

Code of Federal Regulations, 2010 CFR

2010-07-01

... personal safety; e.g., hack-saw blade) A. Recommend parole date rescission or retardation.B. Forfeit earned... disrupts or interferes with the security or orderly running of the institution or the Bureau of Prisons... interferes with the security or orderly running of the institution or the Bureau of Prisons. (Conduct must be...

Search for extraterrestrial intelligence/High Resolution Microwave Survey team member

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1994-01-01

This final report summarizes activities conducted during the three years of the NASA High Resolution Microwave Survey (HRMS). With primary interest in the Sky Survey activity, the principal investigator attended nine Working Group meetings and traveled independently to conduct experiments or present results at other meetings. The major activity involved evaluating the effects of spaceborne radio frequency interference (RFI) on both the SETI sky survey and targeted search. The development of a database of all unclassified earth or biting and deep space transmitters, along with accompanying search software, was a key accomplishment. The software provides information about potential sources of interference and gives complete information regarding the frequencies, positions and levels of interference generated by the spacecraft. A complete description of this search system (called HRS, or HRMS RFI Search) is provided. Other accomplishments include development of a 32,000 channel Fast-Fourier-Transform Spectrum analyzer for use in studies of interference from satellites and in a 1.4 mm SETI observational study. The latest revision of HRS has now been distributed to the extended radio astronomy and SETI community.

Research for the jamming mechanism of high-frequency laser to the laser seeker

NASA Astrophysics Data System (ADS)

Zheng, Xingyuan; Zhang, Haiyang; Wang, Yunping; Feng, Shuang; Zhao, Changming

2013-08-01

High-frequency laser will be able to enter the enemy laser signal processing systems without encoded identification and a copy. That makes it one of the research directions of new interference sources. In order to study the interference mechanism of high-frequency laser to laser guided weapons. According to the principle of high-frequency laser interference, a series of related theoretical models such as a semi-active laser seeker coded identification model, a time door model, multi-signal processing model and a interference signal modulation processing model are established. Then seeker interfere with effective 3σ criterion is proposed. Based on this, the study of the effect of multi-source interference and signal characteristics of the effect of high repetition frequency laser interference are key research. According to the simulation system testing, the results show that the multi-source interference and interference signal frequency modulation can effectively enhance the interference effect. While the interference effect of the interference signal amplitude modulation is not obvious. The research results will provide the evaluation of high-frequency laser interference effect and provide theoretical references for high-frequency laser interference system application.

Disruption of the hormonal network and the enantioselectivity of bifenthrin in trophoblast: maternal-fetal health risk of chiral pesticides.

PubMed

Zhao, Meirong; Zhang, Ying; Zhuang, Shulin; Zhang, Quan; Lu, Chengsheng; Liu, Weiping

2014-07-15

Endocrine-disrupting chemicals (EDCs) can interfere with normal hormone signaling to increase health risks to the maternal-fetal system, yet few studies have been conducted on the currently used chiral EDCs. This work tested the hypothesis that pyrethroids could enantioselectively interfere with trophoblast cells. Cell viability, hormone secretion, and steroidogenesis gene expression of a widely used pyrethroid, bifenthrin (BF), were evaluated in vitro, and the interactions of BF enantiomers with estrogen receptor (ER) were predicted. At low or noncytotoxic concentrations, both progesterone and human chorionic gonadotropin secretion were induced. The expression levels of progesterone receptor and human leukocyte antigen G genes were significantly stimulated. The key regulators of the hormonal cascade, GnRH type-I and its receptor, were both upregulated. The expression levels of selected steroidogenic genes were also significantly altered. Moreover, a consistent enantioselective interference of hormone signaling was observed, and S-BF had greater effects than R-BF. Using molecular docking, the enantioselective endocrine disruption of BF was predicted to be partially due to enantiospecific ER binding affinity. Thus, BF could act through ER to enantioselectively disturb the hormonal network in trophoblast cells. These converging results suggest that the currently used chiral pesticides are of significant concern with respect to maternal-fetal health.

Aerodynamic Interference Due to MSL Reaction Control System

NASA Technical Reports Server (NTRS)

Dyakonov, Artem A.; Schoenenberger, Mark; Scallion, William I.; VanNorman, John W.; Novak, Luke A.; Tang, Chun Y.

2009-01-01

An investigation of effectiveness of the reaction control system (RCS) of Mars Science Laboratory (MSL) entry capsule during atmospheric flight has been conducted. The reason for the investigation is that MSL is designed to fly a lifting actively guided entry with hypersonic bank maneuvers, therefore an understanding of RCS effectiveness is required. In the course of the study several jet configurations were evaluated using Langley Aerothermal Upwind Relaxation Algorithm (LAURA) code, Data Parallel Line Relaxation (DPLR) code, Fully Unstructured 3D (FUN3D) code and an Overset Grid Flowsolver (OVERFLOW) code. Computations indicated that some of the proposed configurations might induce aero-RCS interactions, sufficient to impede and even overwhelm the intended control torques. It was found that the maximum potential for aero-RCS interference exists around peak dynamic pressure along the trajectory. Present analysis largely relies on computational methods. Ground testing, flight data and computational analyses are required to fully understand the problem. At the time of this writing some experimental work spanning range of Mach number 2.5 through 4.5 has been completed and used to establish preliminary levels of confidence for computations. As a result of the present work a final RCS configuration has been designed such as to minimize aero-interference effects and it is a design baseline for MSL entry capsule.

Nonlinear transonic Wall-Interference Assessment/Correction (WIAC) procedures and application to cast-10 airfoil results from the NASA 0.3-m TCT 8- by 24-inch Slotted Wall Test Section (SWTS)

NASA Technical Reports Server (NTRS)

Gumbert, Clyde R.; Green, Lawrence L.; Newman, Perry A.

1989-01-01

From the time that wind tunnel wall interference was recognized to be significant, researchers have been developing methods to alleviate or account for it. Despite the best effort so far, it appears that no method is available which completely eliminates the effects due to the wind tunnel walls. This report discusses procedures developed for slotted wall and adaptive wall test sections of the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) to assess and correct for the residual interference by methods consistent with the transonic nature of the tests.

Synthesis and testing of a conducting polymeric composite material for lightning strike protection applications

NASA Astrophysics Data System (ADS)

Katunin, A.; Krukiewicz, K.; Turczyn, R.; Sul, P.; Łasica, A.; Catalanotti, G.; Bilewicz, M.

2017-02-01

Lightning strike protection is one of the important issues in the modern maintenance problems of aircraft. This is due to a fact that the most of exterior elements of modern aircraft is manufactured from polymeric composites which are characterized by isolating electrical properties, and thus cannot carry the giant electrical charge when the lightning strikes. This causes serious damage of an aircraft structure and necessity of repairs and tests before returning a vehicle to operation. In order to overcome this problem, usually metallic meshes are immersed in the polymeric elements. This approach is quite effective, but increases a mass of an aircraft and significantly complicates the manufacturing process. The approach proposed by the authors is based on a mixture of conducting and dielectric polymers. Numerous modeling studies which are based on percolation clustering using kinetic Monte Carlo methods, finite element modeling of electrical and mechanical properties, and preliminary experimental studies, allow achieving an optimal content of conducting particles in a dielectric matrix in order to achieve possibly the best electrical conductivity and mechanical properties, simultaneously. After manufacturing the samples with optimal content of a conducting polymer, mechanical and electrical characterization as well as high-voltage testing was performed. The application of such a material simplifies manufacturing process and ensures unique properties of aircraft structures, which allows for minimizing damage after lightning strike, as well as provide electrical bounding and grounding, interference shielding, etc. The proposed solution can minimize costs of repair, testing and certification of aircraft structures damaged by lightning strikes.

Lateralized dual task interference in left-handers: initial value differences do not affect the outcome.

PubMed

McBride, D M; Cherry, B J; Kee, D W; Neale, P L

1995-07-01

The study was conducted to clarify factors involved in dual-task finger-tapping interference. Left-handers, as assessed by hand-writing preference and left-hand baseline tapping advantage, tapped both alone and while solving anagrams. Even though the left-hand baseline tapping advantage was experimentally removed on some (adjusted) trials, greater left- than right-hand tapping interference was observed during concurrent task performance. This result coupled with previous findings for right-handed subjects [Kee and Cherry, Neuropsychologia, Vol. 28, pp. 313-316, 1990] indicates that lateralized interference effects are not merely due to initial baseline tapping differences as proposed by Willis and Goodwin [Neuropsychologia, Vol. 25, pp. 719-724, 1987].

Capacity of dental equipment to interfere with cardiac implantable electrical devices.

PubMed

Lahor-Soler, Eduard; Miranda-Rius, Jaume; Brunet-Llobet, Lluís; Sabaté de la Cruz, Xavier

2015-06-01

Patients with cardiac implantable electrical devices should take precautions when exposed to electromagnetic fields. Possible interference as a result of proximity to electromagnets or electricity flow from electronic tools employed in clinical odontology remains controversial. The objective of this study was to examine in vitro the capacity of dental equipment to provoke electromagnetic interference in pacemakers and implantable cardioverter defibrillators. Six electronic dental instruments were tested on three implantable cardioverter defibrillators and three pacemakers from different manufacturers. A simulator model, submerged in physiological saline, with elements that reproduced life-size anatomic structures was used. The instruments were analyzed at differing distances and for different time periods of application. The dental instruments studied displayed significant differences in their capacity to trigger electromagnetic interference. Significant differences in the quantity of registered interference were observed with respect to the variables manufacturer, type of cardiac implant, and application distance but not with the variable time of application. The electronic dental equipment tested at a clinical application distance (20 cm) provoked only slight interference in the pacemakers and implantable cardioverter defibrillators employed, irrespective of manufacturer. © 2015 Eur J Oral Sci.

Body fluid matrix evaluation on a Roche cobas 8000 system.

PubMed

Owen, William E; Thatcher, Mindy L; Crabtree, Karolyn J; Greer, Ryan W; Strathmann, Frederick G; Straseski, Joely A; Genzen, Jonathan R

2015-09-01

Chemical analysis of body fluids is commonly requested by physicians. Because most commercial FDA-cleared clinical laboratory assays are not validated by diagnostic manufacturers for "non-serum" and "non-plasma" specimens, laboratories may need to complete additional validation studies to comply with regulatory requirements regarding body fluid testing. The objective of this report is to perform recovery studies to evaluate potential body fluid matrix interferences for commonly requested chemistry analytes. Using an IRB-approved protocol, previously collected clinical body fluid specimens (biliary/hepatic, cerebrospinal, dialysate, drain, pancreatic, pericardial, peritoneal, pleural, synovial, and vitreous) were de-identified and frozen (-20°C) until experiments were performed. Recovery studies (spiking with high concentration serum, control, and/or calibrator) were conducted using 10% spiking solution by volume; n=5 specimens per analyte/body fluid investigated. Specimens were tested on a Roche cobas 8000 system (c502, c702, e602, and ISE modules). In all 80 analyte/body fluid combinations investigated (including amylase, total bilirubin, urea nitrogen, carbohydrate antigen 19-9, carcinoembryonic antigen, cholesterol, chloride, creatinine, glucose, potassium, lactate dehydrogenase, lipase, rheumatoid factor, sodium, total protein, triglycerides, and uric acid), the average percent recovery was within predefined acceptable limits (less than ±10% from the calculated ideal recovery). The present study provides evidence against the presence of any systematic matrix interference in the analyte/body fluid combinations investigated on the Roche cobas 8000 system. Such findings support the utility of ongoing body fluid validation initiatives conducted to maintain compliance with regulatory requirements. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Study of New Method Combined Ultra-High Frequency (UHF) Method and Ultrasonic Method on PD Detection for GIS

NASA Astrophysics Data System (ADS)

Li, Yanran; Chen, Duo; Zhang, Jiwei; Chen, Ning; Li, Xiaoqi; Gong, Xiaojing

2017-09-01

GIS (gas insulated switchgear), is an important equipment in power system. Partial discharge plays an important role in detecting the insulation performance of GIS. UHF method and ultrasonic method frequently used in partial discharge (PD) detection for GIS. It is necessary to investigate UHF method and ultrasonic method for partial discharge in GIS. However, very few studies have been conducted on the method combined this two methods. From the view point of safety, a new method based on UHF method and ultrasonic method of PD detection for GIS is proposed in order to greatly enhance the ability of anti-interference of signal detection and the accuracy of fault localization. This paper presents study aimed at clarifying the effect of the new method combined UHF method and ultrasonic method. Partial discharge tests were performed in laboratory simulated environment. Obtained results show the ability of anti-interference of signal detection and the accuracy of fault localization for this new method combined UHF method and ultrasonic method.

Study of comparison between Ultra-high Frequency (UHF) method and ultrasonic method on PD detection for GIS

NASA Astrophysics Data System (ADS)

Li, Yanran; Chen, Duo; Li, Li; Zhang, Jiwei; Li, Guang; Liu, Hongxia

2017-11-01

GIS (gas insulated switchgear), is an important equipment in power system. Partial discharge plays an important role in detecting the insulation performance of GIS. UHF method and ultrasonic method frequently used in partial discharge (PD) detection for GIS. However, few studies have been conducted on comparison of this two methods. From the view point of safety, it is necessary to investigate UHF method and ultrasonic method for partial discharge in GIS. This paper presents study aimed at clarifying the effect of UHF method and ultrasonic method for partial discharge caused by free metal particles in GIS. Partial discharge tests were performed in laboratory simulated environment. Obtained results show the ability of anti-interference of signal detection and the accuracy of fault localization for UHF method and ultrasonic method. A new method based on UHF method and ultrasonic method of PD detection for GIS is proposed in order to greatly enhance the ability of anti-interference of signal detection and the accuracy of detection localization.

Interference heating from interactions of shock waves with turbulent boundary layers at Mach 6

NASA Technical Reports Server (NTRS)

Johnson, C. B.; Kaufman, L. G., II

1974-01-01

An experimental investigation of interference heating resulting from interactions of shock waves and turbulent boundary layers was conducted. Pressure and heat-transfer distributions were measured on a flat plate in the free stream and on the wall of the test section of the Langley Mach 6 high Reynolds number tunnel for Reynolds numbers ranging from 2 million to 400 million. Various incident shock strengths were obtained by varying a wedge-shock generator angle (from 10 deg to 15 deg) and by placing a spherical-shock generator at different vertical positions above the instrumented flat plate and tunnel wall. The largest heating-rate amplification factors obtained for completely turbulent boundary layers were 22.1 for the flat plate and 11.6 for the tunnel wall experiments. Maximum heating correlated with peak pressures using a power law with a 0.85 exponent. Measured pressure distributions were compared with those calculated using turbulent free-interaction pressure rise theories, and separation lengths were compared with values calculated by using different methods.

Construction of ferrocene modified conducting polymer based amperometric urea biosensor.

PubMed

Dervisevic, Muamer; Dervisevic, Esma; Senel, Mehmet; Cevik, Emre; Yildiz, Huseyin Bekir; Camurlu, Pınar

2017-07-01

Herein, an electrochemical urea sensing bio-electrode is reported that has been constructed by firstly electropolymerizing 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline monomer (SNS-Aniline) on Pencil Graphite Electrode (PGE), then modifying the polymer coated electrode surface with di-amino-Ferrocene (DAFc) as the mediator, and lastly Urease enzyme through glutaraldehyde crosslinking. The effect of pH, temperature, polymer thickness, and applied potential on the electrode current response was investigated besides performing storage and operational stability experiments with the interference studies. The resulting urea biosensor's amperometric response was linear in the range of 0.1-8.5mM with the sensitivity of 0.54μA/mM, detection limit of 12μM, and short response time of 2s. The designed bio-electrode was tested with real human blood and urine samples where it showed excellent analytical performance with insignificant interference. Copyright © 2017 Elsevier Inc. All rights reserved.

The Auditory Verbal Learning Test (Rey AVLT): An Arabic Version

ERIC Educational Resources Information Center

Sharoni, Varda; Natur, Nazeh

2014-01-01

The goals of this study were to adapt the Rey Auditory Verbal Learning Test (AVLT) into Arabic, to compare recall functioning among age groups (6:0 to 17:11), and to compare gender differences on various memory dimensions (immediate and delayed recall, learning rate, recognition, proactive interferences, and retroactive interferences). This…

IDENTIFICATION OF ALGAE WHICH INTERFERE WITH THE DETECTION OF GIARDIA CYSTS AND CRYPTOSPORIDIUM OOCYSTS AND A METHOD FOR ALLEVIATING THIS INTERFERENCE

EPA Science Inventory

Fifty-four algal species were tested for cross-reaction in the American Society for Testing and Materials Giardia/Cryptosporidium indirect immunofluorescence assay, and 24 showed some degree of fluorescence. Two species, Navicula minima and Synechococcus elongatus, exhibited a br...

"Testing during Study Insulates against the Buildup of Proactive Interference": Correction

ERIC Educational Resources Information Center

Szpunar, Karl K.; McDermott, Kathleen B.; Roedigger, Henry L., III

2009-01-01

Reports an error in "Testing during study insulates against the buildup of proactive interference" by Karl K. Szpunar, Kathleen B. McDermott and Henry L. Roediger III ("Journal of Experimental Psychology: Learning, Memory, and Cognition," 2008[Nov], Vol 34[6], 1392-1399). Incorrect figures were printed due to an error in the…

77 FR 20756 - Implementation of the Local Community Radio Act of 2010; Revision of Service and Eligibility...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-06

... the technical report entitled `Experimental Measurements of the Third-Adjacent Channel Impacts of Low... rules designed to prevent any predicted interference. 31. We propose to adopt a basic threshold test. This test is designed to closely track the interference standard developed by Mitre, without...

Test Plan for Experimental Measurements of Radio Noise and Electromagnetic Interference at Logan and Burlington Airports

DOT National Transportation Integrated Search

1979-10-01

A test plan is designed to" (a) evaluate the performance of several types of LORAN-C receivers in the vicinity of both a large metropolitan and a small rural airport, (b) measure the electromagnetic interference in the LORAN-C band (100+/-50 KHZ) at ...

The Color-Word Interference Test and Its Relation to Performance Impairment under Auditory Distraction.

ERIC Educational Resources Information Center

Thackray, Richard I.; And Others

The ability to resist distraction is an important requirement for air traffic controllers. The study examined the relationship between performance on the Stroop color-word interference test (a suggested measure of distraction susceptibility) and impairment under auditory distraction on a task requiring the subject to generate random sequences of…

Investigation of Conceptual Change about Double-Slit Interference in Secondary School Physics

ERIC Educational Resources Information Center

Kocakulah, Mustafa Sabri; Kural, Mehmet

2010-01-01

In this study, whether or not constructivist teaching of double-slit interference of light has a positive effect on the secondary school students' conceptual change is examined. An achievement test, a conceptual understanding test and semi-structured interviews were used as data collection tools in this mixed methods research. Experimental group…

System Report for the Optical Properties Monitor (OPM) Experiment

NASA Technical Reports Server (NTRS)

Hummer, L.

2001-01-01

This systems report describes how the Optical Properties Monitor (OPM) experiment was developed. Pertinent design parameters are discussed, along with mission information and system requirements to successfully complete the mission. Environmental testing was performed on the OPM to certify it for spaceflight. This testing included vibration, thermal vacuum, electromagnetic interference and conductance, and toxicity tests. Instrument and monitor subsystem performances, including the reflectometer, vacuum ultraviolet, total integrated scatter, atomic oxygen monitor, irradiance monitor, and molecular contamination monitor during the mission are discussed. The OPM experiment was launched aboard the Space Shuttle on mission STS-81 in January 1997 and transferred to the Mir space station. An extravehicular activity (EVA) was performed in April 1997 to attach the OPM experiment to the outside of the Mir/Shuttle Docking Module for space environment exposure. The OPM conducted in situ measurements of a number of material samples. These data may be found in the OPM Science Report. OPM was retrieved during an EVA in January 1998 and was returned to Earth on board the Space Shuttle on mission STS-89.

Hemolysis from a nurses' standpoint--survey from four Croatian hospitals.

PubMed

Dorotić, Adrijana; Antončić, Dragana; Biljak, Vanja Radišić; Nedić, Dara; Beletić, Andjelo

2015-01-01

Hemolysis can occur during sample collection, handling and transport. It is more frequent when the non-laboratory staff performs sampling. The aim of this study was to assess nurses' knowledge on the causes of hemolysis and consequential impact on the laboratory tests results. Additionally, the differences in knowledge, related to work experience, professional degree and previous education about hemolysis were explored. An anonymus survey, containing 11 questions on demographics, causes of hemolysis, its impact on biochemical parameters and nurses' attitude towards additional education in preanalytics, was conducted in four Croatian hospitals. The answers were compared by Chi-squared and Fischer exact test. In total, 562 survey results were collected. Majority of nurses declared familiarity with the term "hemolysis" (99.6%). There were 77% of correct answers regarding questions about the causes of hemolysis, but only 50% when it comes to questions about interference in biochemical tests. The percentage of correct answers about causes was significantly lower (P=0.029) among more experienced nurses, and higher (P=0.027) in those with higher professional degree, while influence of previous education was not significant. Also, higher percentage of correct answers about interferences was encountered in nurses with longer work experience (P=0.039). More than 70% of nurses declared that additional education about preanalytical factors would be beneficial. Croatian nurses are familiar with the definition of hemolysis, but a lack of knowledge about causes and influence on laboratory test results is evident. Nurses are eager to improve their knowledge in this field of preanalytical phase.

Comparing cognition by integrating concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A; Kelly, Debbie M; Katz, Jeffrey S

2018-06-01

This article describes an approach for training a variety of species to learn the abstract concept of same/different, which in turn forms the basis for testing proactive interference and list memory. The stimulus set for concept-learning training was progressively doubled from 8, 16, 32, 64, 128 . . . to 1,024 different pictures with novel-stimulus transfer following learning. All species fully learned the same/different abstract concept: capuchin and rhesus monkeys learned more readily than pigeons; nutcrackers and magpies were at least equivalent to monkeys and transferred somewhat better following initial training sets. A similar task using the 1,024-picture set plus delays was used to test proactive interference on occasional trials. Pigeons revealed greater interference with 10-s than with 1-s delays, whereas delay time had no effect on rhesus monkeys, suggesting that the monkeys' interference was event based. This same single-item same/different task was expanded to a 4-item list memory task to test animal list memory. Humans were tested similarly with lists of kaleidoscope pictures. Delays between the list and test were manipulated, resulting in strong initial recency effects (i.e., strong 4th-item memory) at short delays and changing to a strong primacy effect (i.e., strong 1st-item memory) at long delays (pigeons 0-s to 10-s delays; monkeys 0-s to 30-s delays; humans 0-s to 100-s delays). Results and findings are discussed in terms of these species' cognition and memory comparisons, evolutionary implications, and future directions for testing other species in these synergistically related tasks.

Assessment of virus interference in a test-negative study of influenza vaccine effectiveness

PubMed Central

Feng, Shuo; Fowlkes, Ashley L.; Steffens, Andrea; Finelli, Lyn; Cowling, Benjamin J.

2017-01-01

Background The observational test-negative study design is used to estimate vaccine effectiveness against influenza virus infection. An important assumption of the test-negative design is that vaccination does not affect the risk of infection with another virus. If such virus interference occurred, detection of other respiratory viruses would be more common among influenza vaccine recipients and vaccine effectiveness estimates could differ. We evaluated the potential for virus interference using data from the Influenza Incidence Surveillance Project. Methods From 2010 to 2013, outpatients presenting to clinics in 13 US jurisdictions with acute respiratory infections were tested for influenza and other respiratory viruses. We investigated whether virus interference might affect vaccine effectiveness estimates by first evaluating the sensitivity of estimates using alternative control groups that include or exclude patients with other respiratory virus detections by age group and early/middle/late stage of influenza seasons. Second, we evaluated the association between influenza vaccination receipt and other respiratory virus detection among influenza test negative patients. Results Influenza was detected in 3,743/10,650 patients (35%), and overall vaccine effectiveness was 47% (95% CI: 42%, 52%). Estimates using each control group were consistent overall or when stratified by age groups, and there were no differences among early, middle, or late phase during influenza season. We found no associations between detection of other respiratory viruses and receipt of influenza vaccination. Conclusions In this 3-year test-negative design study in an outpatient setting in the United States, we found no evidence of virus interference or impact on influenza vaccine effectiveness estimation. PMID:28362642

Revealing past memories: proactive interference and ketamine-induced memory deficits.

PubMed

Chrobak, James J; Hinman, James R; Sabolek, Helen R

2008-04-23

Memories of events that occur often are sensitive to interference from memories of similar events. Proactive interference plays an important and often unexamined role in memory testing for spatially and temporally unique events ("episodes"). Ketamine (NMDA receptor antagonist) treatment in humans and other mammals induces a constellation of cognitive deficits, including impairments in working and episodic memory. We examined the effects of the ketamine (2.5-100 mg/kg) on the acquisition, retrieval, and retention of memory in a delayed-match-to-place radial water maze task that can be used to assess proactive interference. Ketamine (2.5-25 mg/kg, i.p.) given 20 min before the sample trial, impaired encoding. The first errors made during the test trial were predominantly to arms located spatially adjacent to the goal arm, suggesting an established albeit weakened representation. Ketamine (25-100 mg/kg) given immediately after the sample trial had no effect on retention. Ketamine given before the test trial impaired retrieval. First errors under the influence of ketamine were predominantly to the goal location of the previous session. Thus, ketamine treatment promoted proactive interference. These memory deficits were not state dependent, because ketamine treatment at both encoding and retrieval only increased the number of errors during the test session. These data demonstrate the competing influence of distinct memory representations during the performance of a memory task in the rat. Furthermore, they demonstrate the subtle disruptive effects of the NMDA antagonist ketamine on both encoding and retrieval. Specifically, ketamine treatment disrupted retrieval by promoting proactive interference from previous episodic representations.

Eighteen-month-olds' memory interference and distraction in a modified A-not-B task is not associated with their anticipatory looking in a false-belief task.

PubMed

Zmyj, Norbert; Prinz, Wolfgang; Daum, Moritz M

2015-01-01

Infants' performance in non-verbal false-belief tasks is often interpreted as if they have understood false beliefs. This view has been questioned by a recent account that explains infants' performance in non-verbal false-belief tasks as the result of susceptibility to memory interference and distraction. We tested this alternative account by investigating the relationship between infants' false-belief understanding, susceptibility to memory interference and distraction, and general cognitive development in 18-month-old infants (N = 22). False-belief understanding was tested in an anticipatory looking paradigm of a standard false-belief task. Susceptibility to memory interference and distraction was tested in a modified A-not-B task. Cognitive development was measured via the Mental Scale of the Bayley Scales of Infant Development. We did not find any relationship between infants' performance in the false-belief task and the A-not-B task, even after controlling for cognitive development. This study shows that there is no ubiquitous relation between susceptibility to memory interference and distraction and performance in a false-belief task in infancy.

Eighteen-month-olds’ memory interference and distraction in a modified A-not-B task is not associated with their anticipatory looking in a false-belief task

PubMed Central

Zmyj, Norbert; Prinz, Wolfgang; Daum, Moritz M.

2015-01-01

Infants’ performance in non-verbal false-belief tasks is often interpreted as if they have understood false beliefs. This view has been questioned by a recent account that explains infants’ performance in non-verbal false-belief tasks as the result of susceptibility to memory interference and distraction. We tested this alternative account by investigating the relationship between infants’ false-belief understanding, susceptibility to memory interference and distraction, and general cognitive development in 18-month-old infants (N = 22). False-belief understanding was tested in an anticipatory looking paradigm of a standard false-belief task. Susceptibility to memory interference and distraction was tested in a modified A-not-B task. Cognitive development was measured via the Mental Scale of the Bayley Scales of Infant Development. We did not find any relationship between infants’ performance in the false-belief task and the A-not-B task, even after controlling for cognitive development. This study shows that there is no ubiquitous relation between susceptibility to memory interference and distraction and performance in a false-belief task in infancy. PMID:26157409

Potential GPRS 900/180-MHz and WCDMA 1900-MHz interference to medical devices.

PubMed

Iskra, Steve; Thomas, Barry W; McKenzie, Ray; Rowley, Jack

2007-10-01

This study compared the potential for interference to medical devices from radio frequency (RF) fields radiated by GSM 900/1800-MHz, general packet radio service (GPRS) 900/1800-MHz, and wideband code division multiple access (WCDMA) 1900-MHz handsets. The study used a balanced half-wave dipole antenna, which was energized with a signal at the standard power level for each technology, and then brought towards the medical device while noting the distance at which interference became apparent. Additional testing was performed with signals that comply with the requirements of the international immunity standard to RF fields, IEC 61000-4-3. The testing provides a sense of the overall interference impact that GPRS and WCDMA (frequency division duplex) may have, relative to current mobile technologies, and to the internationally recognized standard for radiated RF immunity. Ten medical devices were tested: two pulse oximeters, a blood pressure monitor, a patient monitor, a humidifier, three models of cardiac defibrillator, and two models of infusion pump. Our conclusion from this and a related study on consumer devices is that WCDMA handsets are unlikely to be a significant interference threat to medical electronics at typical separation distances.

Malfunction of medical equipment as a result of mains borne interference.

PubMed

Railton, R; Currie, G D; Corner, G A; Evans, A L

1993-08-01

Medical equipment has become more intelligent as the manufacturers have incorporated the latest microprocessor based technology. Equipment malfunction can be caused at any time by inherent errors in the control program but it is particularly important that this is designed to cope with the effects of electrical interference which, in addition, may cause corruption of the software. We have considered interference found in the mains supply in the hospital environment. Using a test protocol with appropriate interference simulators, a wide range of medical equipment was removed temporarily from use and its immunity to electrical mains borne interference tested. Battery operated mains rechargeable devices were unaffected by mains voltage variations including drop-outs and sags whereas mains powered devices were affected to varying degrees of severity. In particular, repetitive drop-outs caused loss of power due to fuse blowing in some life support equipment. Impulses affected 25% and pulse bursts 50% of the equipment tested with some evidence that the more recent designs coped better. The EEC Directive on electro-medical compatibility compliance may cause the design of equipment to be improved but hospitals will have to cope with the above problems in their existing equipment for many years to come.

Invasion-Flowback Processes During Hydraulic Fracturing Well Interference

NASA Astrophysics Data System (ADS)

Kenzhekhanov, Shaken; He, Kai; Xu, Liang; Lord, Paul; Lozano, Martin; Neeves, Keith; Yin, Xiaolong

2017-11-01

Drainage-imbibition cycles that simulate hydraulic fracturing fluid's invasion and flowback during well interference were investigated using NOA81 microfluidic micromodels. Well interference is quite common in unconventional oil and gas fields. It is not unusual for the fracturing fluid injected into a well to be discovered in a nearby well. Normally, the effect of such interference is considered to be negative, as fracturing fluid will be imbibed into the porous rock and block the flow path of hydrocarbons. However, field data show that some interferences are beneficial, and microfluidic experiments presented in this study show that surfactant in the fracturing fluid may be a reason for the observed positive interference. Two fluid drainage-imbibition cycles were conducted in micromodels. The first cycle simulates fracturing of the old well and the second cycle simulates fluid invasion from the new well into the old well's fracture network. The experimental data show that while most such interferences indeed can cause production loss, when the old well's fracturing fluid does not contain surfactant yet the new well's fracturing fluid does, interference can be positive, as the residual water saturation in the porous medium is effectively reduced by surfactants.

Paradoxical effects of testing: retrieval enhances both accurate recall and suggestibility in eyewitnesses.

PubMed

Chan, Jason C K; Langley, Moses M

2011-01-01

Although retrieval practice typically enhances memory retention, it can also impair subsequent eyewitness memory accuracy (Chan, Thomas, & Bulevich, 2009). Specifically, participants who had taken an initial test about a witnessed event were more likely than nontested participants to recall subsequently encountered misinformation—an effect we called retrieval-enhanced suggestibility (RES). Here, we sought to test the generality of RES and to further elucidate its underlying mechanisms. To that end, we tested a dual mechanism account, which suggests that RES occurs because initial testing (a) enhances learning of the later misinformation by reducing proactive interference and (b) causes the reactivated memory trace to be more susceptible to later interference (i.e., a reconsolidation account). Three major findings emerged. First, RES was found after a 1-week delay, where a robust testing benefit occurred for event details that were not contradicted by later misinformation. Second, blockage of reconsolidation was unnecessary for RES to occur. Third, initial testing enhanced learning of the misinformation even when proactive interference played a minimal role.

The effect of interference on temporal order memory for random and fixed sequences in nondemented older adults.

PubMed

Tolentino, Jerlyn C; Pirogovsky, Eva; Luu, Trinh; Toner, Chelsea K; Gilbert, Paul E

2012-05-21

Two experiments tested the effect of temporal interference on order memory for fixed and random sequences in young adults and nondemented older adults. The results demonstrate that temporal order memory for fixed and random sequences is impaired in nondemented older adults, particularly when temporal interference is high. However, temporal order memory for fixed sequences is comparable between older adults and young adults when temporal interference is minimized. The results suggest that temporal order memory is less efficient and more susceptible to interference in older adults, possibly due to impaired temporal pattern separation.

Need for Recovery, Home-Work Interference and Performance: Is Lack of Concentration the Link?

ERIC Educational Resources Information Center

Demerouti, Evangelia; Taris, Toon W.; Bakker, Arnold B.

2007-01-01

This study examines the mechanisms through which experiences in the home domain influence work performance by bringing together the literature on recovery and the work-family interface. A longitudinal study among 123 employees from different organizations was conducted to investigate whether need for recovery and home-work interference (HWI)…

Firefighters' communication transceiver test plan

NASA Astrophysics Data System (ADS)

Wallace, R. J.

1984-05-01

The requirements for the operational testing of the firefighters communication transceiver were identified. The major concerns centered around the integrity and reliability of the firefighter/microphone interface. The major concern about the radio hardware was that it be intrinsically safe in hazardous atmospheres and that the system not interfere with the fit or facial seal of self-contained breathing apparatus (SCBA). The greatest concern for operational testing purposes as the reliability and clarity of the line of communication between the firefighter and those on the fireground with whom he must maintain contact. A desire to test any units developed in both training exercises and in real responses to hazardous material incidents was expressed. It is felt that a VOX-microphone built into the SCBA facemask gives the best performance. A voice-pickup product device which combines a bone conduction microphone and a speaker into a single ear mounted unit is examined.

Firefighters' communication transceiver test plan

NASA Technical Reports Server (NTRS)

Wallace, R. J.

1984-01-01

The requirements for the operational testing of the firefighters communication transceiver were identified. The major concerns centered around the integrity and reliability of the firefighter/microphone interface. The major concern about the radio hardware was that it be intrinsically safe in hazardous atmospheres and that the system not interfere with the fit or facial seal of self-contained breathing apparatus (SCBA). The greatest concern for operational testing purposes as the reliability and clarity of the line of communication between the firefighter and those on the fireground with whom he must maintain contact. A desire to test any units developed in both training exercises and in real responses to hazardous material incidents was expressed. It is felt that a VOX-microphone built into the SCBA facemask gives the best performance. A voice-pickup product device which combines a bone conduction microphone and a speaker into a single ear mounted unit is examined.

The Effect of Interference on Temporal Order Memory for Random and Fixed Sequences in Nondemented Older Adults

ERIC Educational Resources Information Center

Tolentino, Jerlyn C.; Pirogovsky, Eva; Luu, Trinh; Toner, Chelsea K.; Gilbert, Paul E.

2012-01-01

Two experiments tested the effect of temporal interference on order memory for fixed and random sequences in young adults and nondemented older adults. The results demonstrate that temporal order memory for fixed and random sequences is impaired in nondemented older adults, particularly when temporal interference is high. However, temporal order…

High Reynolds Number tests of the NASA SC(2)-0012 airfoil in the Langley 0.3-meter transonic cryogenic tunnel

NASA Technical Reports Server (NTRS)

Mineck, Raymond E.; Lawing, Pierce L.

1987-01-01

A wind-tunnel investigation of the NASA SC(2)-0012 airfoil has been conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel. This investigation supplements the two-dimensional airfoil studies of the Advanced Technology Airfoil Test Program. The Mach number was varied from 0.60 to 0.84. The stagnation temperature and pressure were varied to provide a Reynolds number range from 6 to 40 x 10 to the 6th power based on a 6.0-in. (15.24-cm) airfoil chord. No corrections for wind-tunnel wall interference have been made to the data. The aerodynamic results are presented as integrated force and moment coefficients and pressure distributions without any analysis.

Evaluation of a method to shield a welding electron beam from magnetic interference

NASA Technical Reports Server (NTRS)

Wall, W. A.

1976-01-01

It is known that electron beams are easily deflected by magnetic and electrostatic fields. Therefore, to prevent weld defects, stray electromagnetic fields are avoided in electron beam welding chambers if at all possible. The successful results of tests conducted at MSFC to evaluate a simple magnetic shield made from steel tubing are reported. Tests indicate that this shield was up to 85 percent effective in reducing magnetic effects on the electron beam of a welding machine. In addition, residual magnetic fields within the shield were so nearly uniform that the net effect on the beam alignment was negligible. It is concluded that the shield, with the addition of a tungsten liner, could be used in production welding.

Practical SQUID Instrument for Nondestructive Testing

NASA Technical Reports Server (NTRS)

Tralshawala, N.; Claycomb, J. R.; Miller, John H., Jr.

1997-01-01

We report on the development of a scanning eddy-current imaging system designed to detect deep subsurface flaws in conducting materials. A high transition temperature (high-T c) superconducting quantum interference device (SQUID) magnetometer is employed to provide the required sensitivity at low frequencies, while a combination of small cylindrical high-Tc superconducting and A-metal shields enable the instrument to be scanned in a magnetically noisy environment, rather than the object under test. The shields are arranged to prevent unwanted excitation and ambient noise fields from reaching the SQUID, and to enhance spatial resolution and minimize undesirable edge effects. Thus far, the instrument has successfully detected cracks and pits through 10 layers of aluminum, with a combined thickness of 5 cm at room temperature.

Grounding, bonding and shielding for safety and signal interference control

NASA Technical Reports Server (NTRS)

Forsyth, T. J.; Bautista, AL

1990-01-01

Aircraft models and other aerodynamic tests are conducted at the NASA Ames Research Center National Full Scale Aerodynamics Complex (NFAC). The models, tested in NFAC's wind tunnels, are sometimes heavily instrumented and are connected to a data acquisition system. Besides recording data for evaluation, certain critical information must be monitored to be sure the model is within operational limits. The signals for these parameters are for the most part low-level signals that require good instrumentation amplification. These amplifiers need to be grounded and shielded for common mode rejection and noise reduction. The instrumentation also needs to be grounded to prevent electrical shock hazards. The purpose of this paper is to present an understanding of the principles and purpose of grounding, bonding, and shielding.

The similar effects of verbal and non-verbal intervening tasks on word recall in an elderly population.

PubMed

Williams, B R; Sullivan, S K; Morra, L F; Williams, J R; Donovick, P J

2014-01-01

Vulnerability to retroactive interference has been shown to increase with cognitive aging. Consistent with the findings of memory and aging literature, the authors of the California Verbal Learning Test-II (CVLT-II) suggest that a non-verbal task be administered during the test's delay interval to minimize the effects of retroactive interference on delayed recall. The goal of the present study was to determine the extent to which retroactive interference caused by non-verbal and verbal intervening tasks affects recall of verbal information in non-demented, older adults. The effects of retroactive interference on recall of words during Long-Delay recall on the California Verbal Learning Test-II (CVLT-II) were evaluated. Participants included 85 adults age 60 and older. During a 20-minute delay interval on the CVLT-II, participants received either a verbal (WAIS-III Vocabulary or Peabody Picture Vocabulary Test-IIIB) or non-verbal (Raven's Standard Progressive Matrices or WAIS-III Block Design) intervening task. Similarly to previous research with young adults (Williams & Donovick, 2008), older adults recalled the same number of words across all groups, regardless of the type of intervening task. These findings suggest that the administration of verbal intervening tasks during the CVLT-II do not elicit more retroactive interference than non-verbal intervening tasks, and thus verbal tasks need not be avoided during the delay interval of the CVLT-II.

General mechanism involved in subwavelength optics of conducting microstructures: charge-oscillation-induced light emission and interference.

PubMed

Huang, Xian-Rong; Peng, Ru-Wen

2010-04-01

Interactions between light and conducting microstructures or nanostructures can result in a variety of novel phenomena, but their underlying mechanisms have not been completely understood. From calculations of surface charge density waves on conducting gratings and by comparing them with classical surface plasmons, we revealed a general yet concrete picture regarding the coupling of light to free electron oscillation on structured conducting surfaces that can lead to oscillating subwavelength charge patterns (i.e., structured surface plasmons). New wavelets emitted from these light sources then destructively interfere to form evanescent waves. This principle, usually combined with other mechanisms, is mainly a geometrical effect that can be universally involved in light scattering from all periodic and non-periodic structures containing free electrons. This picture may provide clear guidelines for developing conductor-based nano-optical devices.

An Initial Look at Adjacent Band Interference Between Aeronautical Mobile Telemetry and Long-Term Evolution Wireless Service

DTIC Science & Technology

2016-07-04

required analysis, and further testing. 15. SUBJECT TERMS Adjacent Channel Interference, ACI, LTE -A, LTE , PCM/FM, SOQPSK-TG, ARTM CPM, AWS-3, User...Interference, ACI, LTE -A, LTE , PCM/FM, SOQPSK-TG, ARTM CPM, AWS-3, User Equipment, UE, Evolved Node B, eNodeB, Resource Blocks INTRODUCTION “On...these questions make necessary an improved understanding of the interferers that can be obtained only by hands-on measurements . This work will

Residual interference assessment in adaptive wall wind tunnels

NASA Technical Reports Server (NTRS)

Murthy, A. V.

1989-01-01

A two-variable method is presented which is suitable for on-line calculation of residual interference in airfoil testing in the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-M TCT). The method applies the Cauchy's integral formula to the closed contour formed by the contoured top and bottom walls, and the upstream and downstream ends. The measured top and bottom wall pressures and position are used to calculate the correction to the test Mach number and the airfoil angle of attack. Application to specific data obtained in the 0.3-M TCT adaptive wall test section demonstrates the need to assess residual interference to ensure that the desired level of wall streamlining is achieved. A FORTRAN computer program was developed for on-line calculation of the residual corrections during airfoil tests in the 0.3-M TCT.

Wind tunnel investigation of Nacelle-Airframe interference at Mach numbers of 0.9 to 1.4-pressure data, volume 2

NASA Technical Reports Server (NTRS)

Bencze, D. P.

1976-01-01

Detailed interference force and pressure data were obtained on a representative wing-body nacelle combination at Mach numbers of 0.9 to 1.4. The model consisted of a delta wing-body aerodynamic force model with four independently supported nacelles located beneath the wing-body combination. The primary variables examined included Mach number, angle of attack, nacelle position, and nacelle mass flow ratio. Four different configurations were tested to identify various interference forces and pressures on each component; these included tests of the isolated nacelle, the isolated wing-body combination, the four nacelles as a unit, and the total wing-body-nacelle combination. Nacelle axial location, relative to both the wing-body combination and to each other, was the most important variable in determining the net interference among the components. The overall interference effects were found to be essentially constant over the operating angle-of-attack range of the configuration, and nearly independent of nacelle mass flow ratio.

Intrusive trauma recollections is associated with impairment of interference inhibition and psychomotor speed in PTSD.

PubMed

Kertzman, Semion; Avital, Avi; Weizman, Abraham; Segal, Michael

2014-10-01

Intrusive cognitions that enter consciousness involuntarily are prominent symptoms of posttraumatic stress disorder (PTSD). The present study aimed to identify neuropsychological mechanisms involved. Fifty PTSD outpatients and 50 healthy controls were tested using Finger Tapping, Simple and Choice Reaction Times and Stroop Tasks, to measure motor, psychomotor speed, response selection, and interference inhibition ability respectively. PTSD patients performed poorly in all tests, presumably owing to their generalized slowness of information processing and motor reaction. Psychomotor speed was a predictor of slowness and high error rate during the Stroop. Impaired inhibition, as measured by the interference index of the Stroop task, explained 9.7% of the predicated variance in frequency of re-experiencing PTSD symptoms and 23.5% of the predicated variance in augmentation of the interference response time. Impaired interference control may be related to internal (re-experiencing) and external (sensory) stimuli that leads to cognitive deficits in PTSD patients. Copyright © 2014 Elsevier Inc. All rights reserved.

The development of methods for predicting and measuring distribution patterns of aerial sprays

NASA Technical Reports Server (NTRS)

Ormsbee, A. I.; Bragg, M. B.; Maughmer, M. D.

1979-01-01

The capability of conducting scale model experiments which involve the ejection of small particles into the wake of an aircraft close to the ground is developed. A set of relationships used to scale small-sized dispersion studies to full-size results are experimentally verified and, with some qualifications, basic deposition patterns are presented. In the process of validating these scaling laws, the basic experimental techniques used in conducting such studies, both with and without an operational propeller, were developed. The procedures that evolved are outlined. The envelope of test conditions that can be accommodated in the Langley Vortex Research Facility, which were developed theoretically, are verified using a series of vortex trajectory experiments that help to define the limitations due to wall interference effects for models of different sizes.

Single-task fMRI overlap predicts concurrent multitasking interference.

PubMed

Nijboer, Menno; Borst, Jelmer; van Rijn, Hedderik; Taatgen, Niels

2014-10-15

There is no consensus regarding the origin of behavioral interference that occurs during concurrent multitasking. Some evidence points toward a multitasking locus in the brain, while other results imply that interference is the consequence of task interactions in several brain regions. To investigate this issue, we conducted a functional MRI (fMRI) study consisting of three component tasks, which were performed both separately and in combination. The results indicated that no specific multitasking area exists. Instead, different patterns of activation across conditions could be explained by assuming that the interference is a result of task interactions. Additionally, similarity in single-task activation patterns correlated with a decrease in accuracy during dual-task conditions. Taken together, these results support the view that multitasking interference is not due to a bottleneck in a single "multitasking" brain region, but is a result of interactions between concurrently running processes. Copyright © 2014 Elsevier Inc. All rights reserved.

Measuring pain phenomena after spinal cord injury: Development and psychometric properties of the SCI-QOL Pain Interference and Pain Behavior assessment tools.

PubMed

Cohen, Matthew L; Kisala, Pamela A; Dyson-Hudson, Trevor A; Tulsky, David S

2018-05-01

To develop modern patient-reported outcome measures that assess pain interference and pain behavior after spinal cord injury (SCI). Grounded-theory based qualitative item development; large-scale item calibration field-testing; confirmatory factor analyses; graded response model item response theory analyses; statistical linking techniques to transform scores to the Patient Reported Outcome Measurement Information System (PROMIS) metric. Five SCI Model Systems centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. N/A. Spinal Cord Injury - Quality of Life (SCI-QOL) Pain Interference item bank, SCI-QOL Pain Interference short form, and SCI-QOL Pain Behavior scale. Seven hundred fifty-seven individuals with traumatic SCI completed 58 items addressing various aspects of pain. Items were then separated by whether they assessed pain interference or pain behavior, and poorly functioning items were removed. Confirmatory factor analyses confirmed that each set of items was unidimensional, and item response theory analyses were used to estimate slopes and thresholds for the items. Ultimately, 7 items (4 from PROMIS) comprised the Pain Behavior scale and 25 items (18 from PROMIS) comprised the Pain Interference item bank. Ten of these 25 items were selected to form the Pain Interference short form. The SCI-QOL Pain Interference item bank and the SCI-QOL Pain Behavior scale demonstrated robust psychometric properties. The Pain Interference item bank is available as a computer adaptive test or short form for research and clinical applications, and scores are transformed to the PROMIS metric.

Experimental investigation of wall shock cancellation and reduction of wall interference in transonic testing

NASA Technical Reports Server (NTRS)

Ferri, A.; Roffe, G.

1975-01-01

A series of experiments were performed to evaluate the effectiveness of a three-dimensional land and groove wall geometry and a variable permeability distribution to reduce the interference produced by the porous walls of a supercritical transonic test section. The three-dimensional wall geometry was found to diffuse the pressure perturbations caused by small local mismatches in wall porosity permitting the use of a relatively coarse wall porosity control to reduce or eliminate wall interference effects. The wall porosity distribution required was found to be a sensitive function of Mach number requiring that the Mach number repeatability characteristics of the test apparatus be quite good. The effectiveness of a variable porosity wall is greatest in the upstream region of the test section where the pressure differences across the wall are largest. An effective variable porosity wall in the down stream region of the test section requires the use of a slightly convergent test section geometry.

Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference

PubMed Central

Thürer, Benjamin; Stein, Thorsten

2017-01-01

Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically equivalent fashion (AAA-group) but interference occurred when learning was performed in intrinsically equivalent fashion (ABA-group). PMID:28459833

Evaluation of bilirubin interference and accuracy of six creatinine assays compared with isotope dilution-liquid chromatography mass spectrometry.

PubMed

Nah, Hyunjin; Lee, Sang-Guk; Lee, Kyeong-Seob; Won, Jae-Hee; Kim, Hyun Ok; Kim, Jeong-Ho

2016-02-01

The aim of this study was to estimate bilirubin interference and accuracy of six routine methods for measuring creatinine compared with isotope dilution-liquid chromatography mass spectrometry (ID-LC/MS). A total of 40 clinical serum samples from 31 patients with serum total bilirubin concentration >68.4μmol/L were collected. Serum creatinine was measured using two enzymatic reagents and four Jaffe reagents as well as ID-LC/MS. Correlations between bilirubin concentration and percent difference in creatinine compared with ID-LC/MS were analyzed to investigate bilirubin interference. Bias estimations between the six reagents and ID-LC/MS were performed. Recovery tests using National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 967a were also performed. Both the enzymatic methods showed no bilirubin interference. However, three of the four Jaffe methods demonstrated significant bilirubin concentration-dependent interference in samples with creatinine levels <53μmol/L, and two of them showed significant bilirubin interference in samples with creatinine levels ranging from 53.0 to 97.2μmol/L. Comparison of these methods with ID-LC/MS using patients' samples with elevated bilirubin revealed that the tested methods failed to achieve the bias goal at especially low levels of creatinine. In addition, recovery test using NIST SRM 967a showed that bias in one Jaffe method and two enzymatic methods did not achieve the bias goal at either low or high level of creatinine, indicating they had calibration bias. One enzymatic method failed to achieve all the bias goals in both comparison experiment and recovery test. It is important to understand that both bilirubin interference and calibration traceability to ID-LC/MS should be considered to improve the accuracy of creatinine measurement. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Consecutive learning of opposing unimanual motor tasks using the right arm followed by the left arm causes intermanual interference.

PubMed

Stockinger, Christian; Thürer, Benjamin; Stein, Thorsten

2017-01-01

Intermanual transfer (motor memory generalization across arms) and motor memory interference (impairment of retest performance in consecutive motor learning) are well-investigated motor learning phenomena. However, the interplay of these phenomena remains elusive, i.e., whether intermanual interference occurs when two unimanual tasks are consecutively learned using different arms. Here, we examine intermanual interference when subjects consecutively adapt their right and left arm movements to novel dynamics. We considered two force field tasks A and B which were of the same structure but mirrored orientation (B = -A). The first test group (ABA-group) consecutively learned task A using their right arm and task B using their left arm before being retested for task A with their right arm. Another test group (AAA-group) learned only task A in the same right-left-right arm schedule. Control subjects learned task A using their right arm without intermediate left arm learning. All groups were able to adapt their right arm movements to force field A and both test groups showed significant intermanual transfer of this initial learning to the contralateral left arm of 21.9% (ABA-group) and 27.6% (AAA-group). Consecutively, both test groups adapted their left arm movements to force field B (ABA-group) or force field A (AAA-group). For the ABA-group, left arm learning caused significant intermanual interference of the initially learned right arm task (68.3% performance decrease). The performance decrease of the AAA-group (10.2%) did not differ from controls (15.5%). These findings suggest that motor control and learning of right and left arm movements involve partly similar neural networks or underlie a vital interhemispheric connectivity. Moreover, our results suggest a preferred internal task representation in extrinsic Cartesian-based coordinates rather than in intrinsic joint-based coordinates because interference was absent when learning was performed in extrinsically equivalent fashion (AAA-group) but interference occurred when learning was performed in intrinsically equivalent fashion (ABA-group).

Potential for Personal Digital Assistant interference with implantable cardiac devices.

PubMed

Tri, Jeffrey L; Trusty, Jane M; Hayes, David L

2004-12-01

To determine whether the wireless local area network (WLAN) technology, specifically the Personal Digital Assistant (PDA), interferes with implantable cardiac pacemakers and defibrillators. Various pacemakers and defibrillators were tested in vitro at the Mayo Clinic in Rochester, Minn, between March 6 and July 30, 2003. These cardiac devices were exposed to an HP Compaq IPAQ PDA fitted with a Cisco Aironet WLAN card. Initial testing was designed to show whether the Aironet card radiated energy in a consistent pattern from the antenna of the PDA to ensure that subsequent cardiac device testing would not be affected by the orientation of the PDA to the cardiac device. Testing involved placing individual cardiac devices in a simulator and uniformly exposing each device at its most sensitive programmable value to the WLAN card set to maximum power. During testing with the Cisco WLAN Aironet card, all devices programmed to the unipolar or bipolar configuration single- or dual-chamber mode had normal pacing and sensing functions and exhibited no effects of electromagnetic interference except for 1 implantable cardioverter-defibrillator (ICD). This aberration was determined to relate to the design of the investigators' testing apparatus and not to the output of the PDA. The ICD device appropriately identified and labeled the electromagnetic aberration as "noise." We documented no electromagnetic interference caused by the WLAN technology by using in vitro testing of pacemakers and ICDs; however, testing ideally should be completed in vivo to confirm the lack of any clinically important interactions.

Contributions of Response Set and Semantic Relatedness to Cross-Modal Stroop-Like Picture--Word Interference in Children and Adults

ERIC Educational Resources Information Center

Hanauer, John B.; Brooks, Patricia J.

2005-01-01

Resistance to interference from irrelevant auditory stimuli undergoes development throughout childhood. To test whether semantic processes account for age-related changes in a Stroop-like picture-word interference effect, children (3-to 12-year-olds) and adults named pictures while listening to words varying in terms of semantic relatedness to the…

Language Proficiency and Executive Control in Proactive Interference: Evidence from Monolingual and Bilingual Children and Adults

ERIC Educational Resources Information Center

Bialystok, Ellen; Feng, Xiaojia

2009-01-01

Two studies are reported in which monolingual and bilingual children (Study 1) and adults (Study 2) completed a memory task involving proactive interference. In both cases, the bilinguals attained lower scores on a vocabulary test than monolinguals but performed the same on the proactive interference task. For the children, bilinguals made fewer…

The Effects of Pictorial Aids on Inferentially-produced Interference in Younger and Older Children's Sentence Learning.

ERIC Educational Resources Information Center

Truman, Diane L.

As part of a series of studies dealing with varieties of interference in sentence learning as assessed by multiple choice tests, a study was undertaken to explore the effects of pictures on inferentially produced interference in recognition memory for sentence information. The subjects were 104 first grade students and 104 fourth, fifth, and sixth…

A Test of Bayesian Observer Models of Processing in the Eriksen Flanker Task

ERIC Educational Resources Information Center

White, Corey N.; Brown, Scott; Ratcliff, Roger

2012-01-01

Two Bayesian observer models were recently proposed to account for data from the Eriksen flanker task, in which flanking items interfere with processing of a central target. One model assumes that interference stems from a perceptual bias to process nearby items as if they are compatible, and the other assumes that the interference is due to…

Comparison study and thoron interference test of different radon monitors.

PubMed

Sumesh, C G; Kumar, A Vinod; Tripathi, R M; Puranik, V D

2013-03-01

A comparison study and thoron interference test for different continuous radon monitors were carried out. The comparison study includes three passive diffusion monitors [one pulse ionisation chamber based-Alpha Guard and two silicon semi-conductor based-Radon Scout Plus (RSP)] and one silicon semi-conductor-based active radon thoron discriminating monitor--RAD 7. Radon emanation standard, supplied by National Institute of Science and Technology, has been utilised for the comparison study to qualify the calibration of the continuous radon monitors. All the instruments showed good agreement with the estimated radon concentration using (226)Ra/(222)Rn emanation standard. It was found that the active radon monitoring system is having a higher initial response towards the transient radon concentration than the passive radon monitors studied. The instruments measuring radon concentration without energy discrimination are likely to have some sensitivity towards the thoron concentration. Thus, thoron interference study was carried out in the above monitors. Nine percent interference in measured radon concentration in the Alpha Guard monitor and 4 % interference in the semi-conductor-based RSP monitors was observed. Study indicates that the interference of thoron in radon monitors depends on the area of diffusion of gas, volume of detection and sensitivity factor.

Interference correction by extracting the information of interference dominant regions: Application to near-infrared spectra

NASA Astrophysics Data System (ADS)

Bi, Yiming; Tang, Liang; Shan, Peng; Xie, Qiong; Hu, Yong; Peng, Silong; Tan, Jie; Li, Changwen

2014-08-01

Interference such as baseline drift and light scattering can degrade the model predictability in multivariate analysis of near-infrared (NIR) spectra. Usually interference can be represented by an additive and a multiplicative factor. In order to eliminate these interferences, correction parameters are needed to be estimated from spectra. However, the spectra are often mixed of physical light scattering effects and chemical light absorbance effects, making it difficult for parameter estimation. Herein, a novel algorithm was proposed to find a spectral region automatically that the interesting chemical absorbance and noise are low, that is, finding an interference dominant region (IDR). Based on the definition of IDR, a two-step method was proposed to find the optimal IDR and the corresponding correction parameters estimated from IDR. Finally, the correction was performed to the full spectral range using previously obtained parameters for the calibration set and test set, respectively. The method can be applied to multi target systems with one IDR suitable for all targeted analytes. Tested on two benchmark data sets of near-infrared spectra, the performance of the proposed method provided considerable improvement compared with full spectral estimation methods and comparable with other state-of-art methods.

All Fatigue is Not Created Equal: The Association of Fatigue and Its Subtypes on Pain Interference in Orofacial Pain.

PubMed

Boggero, Ian A; Rojas-Ramirez, Marcia V; Carlson, Charles R

2017-03-01

Fatigue is known to be a pathway through which depression, psychological distress, pain intensity, and sleep disturbance influence pain interference, but the independent effects of fatigue on pain interference after controlling for these variables remains unknown. In addition, no study to date has tested whether fatigue subtypes of general fatigue, mental fatigue, emotional fatigue, physical fatigue, or vigor differentially predict pain interference. The current study tested these associations using archival medical data of 2133 chronic orofacial pain patients, who completed a battery of psychological questionnaires at the time of their first appointment at an orofacial pain clinic. Hierarchical linear regression analysis revealed that after controlling for depression, psychological distress, sleep disturbance, pain intensity, and demographic variables, fatigue predicted higher pain interference (B=0.70, SE=0.17, P<0.001, η=0.01). Physical fatigue (B=1.70, SE=0.48, P<0.001, η=0.01) and vigor (B=-3.24, SE=0.47, P<0.001, η=0.03) were independently associated with pain interference after controlling for the aforementioned variables. The findings suggest that fatigue is an important independent predictor of pain interference and not merely a mediator. These findings also suggest that not all fatigue is created equal. Interventions aimed at reducing pain interference should target specific fatigue symptoms of physical fatigue and vigor. Future research investigating the independent associations of fatigue subtypes on pain outcomes may help clarify the nature of the interrelationships between pain and fatigue.

Shared and Disorder-Specific Prefrontal Abnormalities in Boys with Pure Attention-Deficit/Hyperactivity Disorder Compared to Boys with Pure CD during Interference Inhibition and Attention Allocation

ERIC Educational Resources Information Center

Rubia, Katya; Halari, Rozmin; Smith, Anna B.; Mohammad, Majeed; Scott, Stephen; Brammer, Michael J.

2009-01-01

Background: Inhibitory and attention deficits have been suggested to be shared problems of disruptive behaviour disorders. Patients with attention deficit hyperactivity disorder (ADHD) and patients with conduct disorder (CD) show deficits in tasks of attention allocation and interference inhibition. However, functional magnetic resonance imaging…

Focusing the Search: Proactive and Retroactive Interference and the Dynamics of Free Recall

ERIC Educational Resources Information Center

Unsworth, Nash; Brewer, Gene A.; Spillers, Gregory J.

2013-01-01

Targeting information in long-term memory is an important cognitive ability, but one that is not well understood. In this study, 4 experiments were conducted to examine the influence of proactive and retroactive interference on memory targeting. Participants were given either 1 or 2 lists and asked to recall List 1, List 2, or in some cases both…

The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but no Proactive Interference

PubMed Central

Oberauer, Klaus; Awh, Edward; Sutterer, David W.

2016-01-01

We report four experiments examining whether associations in visual working memory are subject to proactive interference from long term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of three concrete objects in an array. Each array in the WM test consisted of one old (previously learned) object with a new color (old-mismatch), one old object with its old color (old-match), and one new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from long term memory. In the old mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. PMID:27685018

Verbal Serial List Learning in Mild Cognitive Impairment: A Profile Analysis of Interference, Forgetting, and Errors

PubMed Central

Libon, David J.; Bondi, Mark W.; Price, Catherine C.; Lamar, Melissa; Eppig, Joel; Wambach, Denene M.; Nieves, Christine; Delano-Wood, Lisa; Giovannetti, Tania; Lippa, Carol; Kabasakalian, Anahid; Cosentino, Stephanie; Swenson, Rod; Penney, Dana L.

2012-01-01

Using cluster analysis Libon et al. (2010) found three verbal serial list-learning profiles involving delay memory test performance in patients with mild cognitive impairment (MCI). Amnesic MCI (aMCI) patients presented with low scores on delay free recall and recognition tests; mixed MCI (mxMCI) patients scored higher on recognition compared to delay free recall tests; and dysexecutive MCI (dMCI) patients generated relatively intact scores on both delay test conditions. The aim of the current research was to further characterize memory impairment in MCI by examining forgetting/savings, interference from a competing word list, intrusion errors/perseverations, intrusion word frequency, and recognition foils in these three statistically determined MCI groups compared to normal control (NC) participants. The aMCI patients exhibited little savings, generated more highly prototypic intrusion errors, and displayed indiscriminate responding to delayed recognition foils. The mxMCI patients exhibited higher saving scores, fewer and less prototypic intrusion errors, and selectively endorsed recognition foils from the interference list. dMCI patients also selectively endorsed recognition foils from the interference list but performed similarly compared to NC participants. These data suggest the existence of distinct memory impairments in MCI and caution against the routine use of a single memory test score to operationally define MCI. PMID:21880171

Interference with olfactory memory by visual and verbal tasks.

PubMed

Annett, J M; Cook, N M; Leslie, J C

1995-06-01

It has been claimed that olfactory memory is distinct from memory in other modalities. This study investigated the effectiveness of visual and verbal tasks in interfering with olfactory memory and included methodological changes from other recent studies. Subjects were allocated to one of four experimental conditions involving interference tasks [no interference task; visual task; verbal task; visual-plus-verbal task] and presented 15 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Recognition and recall performance both showed effects of interference of visual and verbal tasks but there was no effect for time of testing. While the results may be accommodated within a dual coding framework, further work is indicated to resolve theoretical issues relating to task complexity.

Interference of medical contrast media on laboratory testing.

PubMed

Lippi, Giuseppe; Daves, Massimo; Mattiuzzi, Camilla

2014-01-01

The use of contrast media such as organic iodine molecules and gadolinium contrast agents is commonplace in diagnostic imaging. Although there is widespread perception that side effects and drug interactions may be the leading problems caused by these compounds, various degrees of interference with some laboratory tests have been clearly demonstrated. Overall, the described interference for iodinate contrast media include inappropriate gel barrier formation in blood tubes, the appearance of abnormal peaks in capillary zone electrophoresis of serum proteins, and a positive bias in assessment of cardiac troponin I with one immunoassay. The interference for gadolinium contrast agents include negative bias in calcium assessment with ortho-cresolphthalein colorimetric assays and occasional positive bias using some Arsenazo reagents, negative bias in measurement of angiotensin converting enzyme (ACE) and zinc (colorimetric assay), as well as positive bias in creatinine (Jaffe reaction), total iron binding capacity (TIBC, ferrozine method), magnesium (calmagite reagent) and selenium (mass spectrometry) measurement. Interference has also been reported in assessment of serum indices, pulse oximetry and methaemoglobin in samples of patients receiving Patent Blue V. Under several circumstances the interference was absent from manufacturer-supplied information and limited to certain type of reagents and/or analytes, so that local verification may be advisable to establish whether or not the test in use may be biased. Since the elimination half-life of these compounds is typically lower than 2 h, blood collection after this period may be a safer alternative in patients who have received contrast media for diagnostic purposes.

Interference of medical contrast media on laboratory testing

PubMed Central

Lippi, Giuseppe; Daves, Massimo; Mattiuzzi, Camilla

2014-01-01

The use of contrast media such as organic iodine molecules and gadolinium contrast agents is commonplace in diagnostic imaging. Although there is widespread perception that side effects and drug interactions may be the leading problems caused by these compounds, various degrees of interference with some laboratory tests have been clearly demonstrated. Overall, the described interference for iodinate contrast media include inappropriate gel barrier formation in blood tubes, the appearance of abnormal peaks in capillary zone electrophoresis of serum proteins, and a positive bias in assessment of cardiac troponin I with one immunoassay. The interference for gadolinium contrast agents include negative bias in calcium assessment with ortho-cresolphthalein colorimetric assays and occasional positive bias using some Arsenazo reagents, negative bias in measurement of angiotensin converting enzyme (ACE) and zinc (colorimetric assay), as well as positive bias in creatinine (Jaffe reaction), total iron binding capacity (TIBC, ferrozine method), magnesium (calmagite reagent) and selenium (mass spectrometry) measurement. Interference has also been reported in assessment of serum indices, pulse oximetry and methaemoglobin in samples of patients receiving Patent Blue V. Under several circumstances the interference was absent from manufacturer-supplied information and limited to certain type of reagents and/or analytes, so that local verification may be advisable to establish whether or not the test in use may be biased. Since the elimination half-life of these compounds is typically lower than 2 h, blood collection after this period may be a safer alternative in patients who have received contrast media for diagnostic purposes. PMID:24627717

Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

PubMed

Kim, Sungshin; Oh, Youngmin; Schweighofer, Nicolas

2015-01-01

Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI) condition (SHORT-ITI); a long ITI condition (LONG-ITI); and an alternating condition with two alternated opposite tasks (ALT), with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

Impact of IRT item misfit on score estimates and severity classifications: an examination of PROMIS depression and pain interference item banks.

PubMed

Zhao, Yue

2017-03-01

In patient-reported outcome research that utilizes item response theory (IRT), using statistical significance tests to detect misfit is usually the focus of IRT model-data fit evaluations. However, such evaluations rarely address the impact/consequence of using misfitting items on the intended clinical applications. This study was designed to evaluate the impact of IRT item misfit on score estimates and severity classifications and to demonstrate a recommended process of model-fit evaluation. Using secondary data sources collected from the Patient-Reported Outcome Measurement Information System (PROMIS) wave 1 testing phase, analyses were conducted based on PROMIS depression (28 items; 782 cases) and pain interference (41 items; 845 cases) item banks. The identification of misfitting items was assessed using Orlando and Thissen's summed-score item-fit statistics and graphical displays. The impact of misfit was evaluated according to the agreement of both IRT-derived T-scores and severity classifications between inclusion and exclusion of misfitting items. The examination of the presence and impact of misfit suggested that item misfit had a negligible impact on the T-score estimates and severity classifications with the general population sample in the PROMIS depression and pain interference item banks, implying that the impact of item misfit was insignificant. Findings support the T-score estimates in the two item banks as robust against item misfit at both the group and individual levels and add confidence to the use of T-scores for severity diagnosis in the studied sample. Recommendations on approaches for identifying item misfit (statistical significance) and assessing the misfit impact (practical significance) are given.

Evaluation of a Mobile Phone for Aircraft GPS Interference

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.

2004-01-01

Measurements of spurious emissions from a mobile phone are conducted in a reverberation chamber for the Global Positioning System (GPS) radio frequency band. This phone model was previously determined to have caused interference to several aircraft GPS receivers. Interference path loss (IPL) factors are applied to the emission data, and the outcome compared against GPS receiver susceptibility. The resulting negative safety margins indicate there are risks to aircraft GPS systems. The maximum emission level from the phone is also shown to be comparable with some laptop computer's emissions, implying that laptop computers can provide similar risks to aircraft GPS receivers.

Aerodynamic heating to representative SRB and ET protuberances

NASA Technical Reports Server (NTRS)

Engel, C. D.; Lapointe, J. K.

1979-01-01

Heating data and data scaling methods which can be used on representative solid rocket booster and external tank (ET) protuberances are described. Topics covered include (1) ET geometry and heating points; (2) interference heating test data (51A); (3) heat transfer data from tests FH-15 and FH-16; (4) individual protuberance data; and (5) interference heating of paint data from test IH-42. A set of drawings of the ET moldline and protuberances is included.

A method for testing the spectraltransmittance of infrared smoke interference

NASA Astrophysics Data System (ADS)

Lei, Hao; Zhang, Yazhou; Wang, Guangping; Wu, Jingli

2018-02-01

Infrared smoke is mainly used for shielding, blind, deception and recognition on the battlefield. The traditional shelter smoke is mainly placed in the friendly positions or positions between the friendly positions and enemy positions, to reduce the enemy observation post investigative capacity. The passive interference capability of the smoke depends on the infrared extinction ability of the smoke. The infrared transmittance test is an objective and accurate representation of the extinction ability of the smoke. In this paper, a method for testing the spectral transmittance of infrared smoke interference is introduced. The uncertainty of the measurement results is analyzed. The results show that this method can effectively obtain the spectral transmittance of the infrared smoke and uncertainty of the measurement is 7.16%, which can be effective for the smoke detection, smoke composition analysis, screening effect evaluation to provide test parameters support.

Theory and application of high temperature superconducting eddy current probes for nondestructive evaluation

NASA Astrophysics Data System (ADS)

Claycomb, James Ronald

1998-10-01

Several High-T c Superconducting (HTS) eddy current probes have been developed for applications in electromagnetic nondestructive evaluation (NDE) of conducting materials. The probes utilize high-T c SUperconducting Quantum Interference Device (SQUID) magnetometers to detect the fields produced by the perturbation of induced eddy currents resulting from subsurface flaws. Localized HTS shields are incorporated to selectively screen out environmental electromagnetic interference and enable movement of the instrument in the Earth's magnetic field. High permeability magnetic shields are employed to focus flux into, and thereby increase the eddy current density in the metallic test samples. NDE test results are presented, in which machined flaws in aluminum alloy are detected by probes of different design. A novel current injection technique performing NDE of wires using SQUIDs is also discussed. The HTS and high permeability shields are designed based on analytical and numerical finite element method (FEM) calculations presented here. Superconducting and high permeability magnetic shields are modeled in uniform noise fields and in the presence of dipole fields characteristic of flaw signals. Several shield designs are characterized in terms of (1) their ability to screen out uniform background noise fields; (2) the resultant improvement in signal-to-noise ratio and (3) the extent to which dipole source fields are distorted. An analysis of eddy current induction is then presented for low frequency SQUID NDE. Analytical expressions are developed for the induced eddy currents and resulting magnetic fields produced by excitation sources above conducting plates of varying thickness. The expressions derived here are used to model the SQUID's response to material thinning. An analytical defect model is also developed, taking into account the attenuation of the defect field through the conducting material, as well as the current flow around the edges of the flaw. Time harmonic FEM calculations are then used to model the electromagnetic response of eight probe designs, consisting of an eddy current drive coil coupled to a SQUID surrounded by superconducting and/or high permeability magnetic shielding. Simulations are carried out with the eddy current probes located a finite distance above a conducting surface. Results are quantified in terms of shielding and focus factors for each probe design.

Dynamic memory searches: Selective output interference for the memory of facts.

PubMed

Aue, William R; Criss, Amy H; Prince, Melissa A

2015-12-01

The benefits of testing on later memory performance are well documented; however, the manner in which testing harms memory performance is less well understood. This research is concerned with the finding that accuracy decreases over the course of testing, a phenomena termed "output interference" (OI). OI has primarily been investigated with episodic memory, but there is limited research investigating OI in measures of semantic memory (i.e., knowledge). In the current study, participants were twice tested for their knowledge of factual questions; they received corrective feedback during the first test. No OI was observed during the first test, when participants presumably searched semantic memory to answer the general-knowledge questions. During the second test, OI was observed. Conditional analyses of Test 2 performance revealed that OI was largely isolated to questions answered incorrectly during Test 1. These were questions for which participants needed to rely on recent experience (i.e., the feedback in episodic memory) to respond correctly. One possible explanation is that episodic memory is more susceptible to the sort of interference generated during testing (e.g., gradual changes in context, encoding/updating of items) relative to semantic memory. Alternative explanations are considered.

The Effect of Reduction Gearing on Propeller-body Interference as Shown by Full-Scale Wind-Tunnel Tests

NASA Technical Reports Server (NTRS)

Weick, Fred E

1931-01-01

This report presents the results of full-scale tests made on a 10-foot 5-inch propeller on a geared J-5 engine and also on a similar 8-foot 11-inch propeller on a direct-drive J-5 engine. Each propeller was tested at two different pitch settings, and with a large and a small fuselage. The investigation was made in such a manner that the propeller-body interference factors were isolated, and it was found that, considering this interference only, the geared propellers had an appreciable advantage in propulsive efficiency, partially due to the larger diameter of the propellers with respect to the bodies, and partially because the geared propellers were located farther ahead of the engines and bodies.

Residual interference and wind tunnel wall adaption

NASA Technical Reports Server (NTRS)

Mokry, Miroslav

1989-01-01

Measured flow variables near the test section boundaries, used to guide adjustments of the walls in adaptive wind tunnels, can also be used to quantify the residual interference. Because of a finite number of wall control devices (jacks, plenum compartments), the finite test section length, and the approximation character of adaptation algorithms, the unconfined flow conditions are not expected to be precisely attained even in the fully adapted stage. The procedures for the evaluation of residual wall interference are essentially the same as those used for assessing the correction in conventional, non-adaptive wind tunnels. Depending upon the number of flow variables utilized, one can speak of one- or two-variable methods; in two dimensions also of Schwarz- or Cauchy-type methods. The one-variable methods use the measured static pressure and normal velocity at the test section boundary, but do not require any model representation. This is clearly of an advantage for adaptive wall test section, which are often relatively small with respect to the test model, and for the variety of complex flows commonly encountered in wind tunnel testing. For test sections with flexible walls the normal component of velocity is given by the shape of the wall, adjusted for the displacement effect of its boundary layer. For ventilated test section walls it has to be measured by the Calspan pipes, laser Doppler velocimetry, or other appropriate techniques. The interface discontinuity method, also described, is a genuine residual interference assessment technique. It is specific to adaptive wall wind tunnels, where the computation results for the fictitious flow in the exterior of the test section are provided.

Real-Time linux dynamic clamp: a fast and flexible way to construct virtual ion channels in living cells.

PubMed

Dorval, A D; Christini, D J; White, J A

2001-10-01

We describe a system for real-time control of biological and other experiments. This device, based around the Real-Time Linux operating system, was tested specifically in the context of dynamic clamping, a demanding real-time task in which a computational system mimics the effects of nonlinear membrane conductances in living cells. The system is fast enough to represent dozens of nonlinear conductances in real time at clock rates well above 10 kHz. Conductances can be represented in deterministic form, or more accurately as discrete collections of stochastically gating ion channels. Tests were performed using a variety of complex models of nonlinear membrane mechanisms in excitable cells, including simulations of spatially extended excitable structures, and multiple interacting cells. Only in extreme cases does the computational load interfere with high-speed "hard" real-time processing (i.e., real-time processing that never falters). Freely available on the worldwide web, this experimental control system combines good performance. immense flexibility, low cost, and reasonable ease of use. It is easily adapted to any task involving real-time control, and excels in particular for applications requiring complex control algorithms that must operate at speeds over 1 kHz.

The role of test expectancy in the build-up of proactive interference in long-term memory.

PubMed

Weinstein, Yana; Gilmore, Adrian W; Szpunar, Karl K; McDermott, Kathleen B

2014-07-01

We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not taken any tests on previous lists, and 2 other groups (one tested and the other untested) who were warned about the upcoming test prior to study of the fifth list. In both experiments, the untested/warned group performed significantly better than the untested/unwarned group on both correct recall and prior list intrusions but did not achieve the same recall accuracy as tested groups. In Experiment 2, an instruction manipulation check further narrowed the gap between the untested/warned group and the tested groups. In addition, we verified that a reduction in test expectancy indeed occurred in the untested group compared with the tested group by asking participants to indicate how likely they believed they were to receive a test on each studied list. These findings suggest that testing protects against proactive interference largely via attentional processes and/or more effective encoding. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Another look at retroactive and proactive interference: a quantitative analysis of conversion processes.

PubMed

Blank, Hartmut

2005-02-01

Traditionally, the causes of interference phenomena were sought in "real" or "hard" memory processes such as unlearning, response competition, or inhibition, which serve to reduce the accessibility of target items. I propose an alternative approach which does not deny the influence of such processes but highlights a second, equally important, source of interference-the conversion (Tulving, 1983) of accessible memory information into memory performance. Conversion is conceived as a problem-solving-like activity in which the rememberer tries to find solutions to a memory task. Conversion-based interference effects are traced to different conversion processes in the experimental and control conditions of interference designs. I present a simple theoretical model that quantitatively predicts the resulting amount of interference. In two paired-associate learning experiments using two different types of memory tests, these predictions were corroborated. Relations of the present approach to traditional accounts of interference phenomena and implications for eyewitness testimony are discussed.

Susceptibility to declarative memory interference is pronounced in primary insomnia.

PubMed

Griessenberger, Hermann; Heib, Dominik P J; Lechinger, Julia; Luketina, Nikolina; Petzka, Marit; Moeckel, Tina; Hoedlmoser, Kerstin; Schabus, Manuel

2013-01-01

Sleep has been shown to stabilize memory traces and to protect against competing interference in both the procedural and declarative memory domain. Here, we focused on an interference learning paradigm by testing patients with primary insomnia (N = 27) and healthy control subjects (N = 21). In two separate experimental nights with full polysomnography it was revealed that after morning interference procedural memory performance (using a finger tapping task) was not impaired in insomnia patients while declarative memory (word pair association) was decreased following interference. More specifically, we demonstrate robust associations of central sleep spindles (in N3) with motor memory susceptibility to interference as well as (cortically more widespread) fast spindle associations with declarative memory susceptibility. In general the results suggest that insufficient sleep quality does not necessarily show up in worse overnight consolidation in insomnia but may only become evident (in the declarative memory domain) when interference is imposed.

Small Business Innovation Research (SBIR) Program. FY 1991 Program Solicitation 91.2

DTIC Science & Technology

1991-07-01

Based Robotic Control Systems Technology A91-034 Passive Sensor Self- Interference Cancellation A91-035 High Performance Propelling Charges A91-036...laboratory tests. A91-034 TITLE: Passive Sensor Self- Interference Cancellation CATEGORY: Exploratory Development OBJECTIVE: Develop practical and effective...acoustic sensor to detect, classify, identify, and locate targets is ARMY 19 degraded by own-platform noise and local interference . Elementary

The Effect of Colour-Word Interference on Children's Memory for Words.

ERIC Educational Resources Information Center

Malliet, Gineva M.

The Stroop color-word test involves a conflict situation in which subjects are asked to say aloud the ink color used to print a color word on a card. Interference occurs when the ink color is in conflict with the color word, such as 'red' printed in green ink. On the other hand, little interference occurs when asked to name the color words…

Analyzing slug tests in wells screened across the watertable: A field assessment

USGS Publications Warehouse

Stanford, K.L.; McElwee, C.D.

2000-01-01

The slug test is the most widely used technique for the in situ estimation of hydraulic conductivity in confined and unconfined formations. Currently, there are no generally accepted methods in the groundwater literature for the analysis of response data from slug tests performed in wells screened across the watertable. A field study was undertaken in an attempt to develop a set of practical guidelines for tests conducted in such wells. Three wells, screened within unconsolidated material exhibiting a range of hydraulic conductivities (.05-30.0 m/day), were installed to depths of up to 9 m (30 ft) in Kansas River alluvium that ranges in thickness from 15 m to 21 m (50 ft to 70 ft) near Lawrence, Kansas. Intensive well-development efforts removed any drilling debris that could interfere with well-formation hydraulics. Once the wells were developed properly, a series of slug tests was performed at each well. The tests were designed to assess the role of the unsaturated zone and the appropriateness of assuming a fixed hydraulic head upper boundary. The results of this investigation can be summarized as follows: (1) the sufficiency of well development should be based on repeat slug tests and not the clarity of pumped water; (2) the effective screen radius for best model analysis should be based on a mass balance and not nominal screen dimensions; (3) the watertable can be represented as a constant head boundary and flow in the unsaturated zone can be ignored in most situations; (4) conventional techniques for the analysis of slug-test data seem to be reasonable for slug tests conducted in wells screened across the watertable, when used with the appropriate effective screen radius and normalized head range; and (5) fluctuations in the watertable elevation through time can be exploited to obtain some insight into the nature of vertical variation in hydraulic conductivity at a well. The results of this investigation indicate that multiple slug tests should be performed at wells screened across the watertable in order to reliably assess the sufficiency of well development and the appropriateness of conventional theory. ?? 2000 International Association for Mathematical Geology.

Turbulent Navier-Stokes Flow Analysis of an Advanced Semispan Diamond-Wing Model in Tunnel and Free Air at High-Lift Conditions

NASA Technical Reports Server (NTRS)

Ghaffari, Farhad; Biedron, Robert T.; Luckring, James M.

2002-01-01

Turbulent Navier-Stokes computational results are presented for an advanced diamond wing semispan model at low-speed, high-lift conditions. The numerical results are obtained in support of a wind-tunnel test that was conducted in the National Transonic Facility at the NASA Langley Research Center. The model incorporated a generic fuselage and was mounted on the tunnel sidewall using a constant-width non-metric standoff. The computations were performed at to a nominal approach and landing flow conditions.The computed high-lift flow characteristics for the model in both the tunnel and in free-air environment are presented. The computed wing pressure distributions agreed well with the measured data and they both indicated a small effect due to the tunnel wall interference effects. However, the wall interference effects were found to be relatively more pronounced in the measured and the computed lift, drag and pitching moment. Although the magnitudes of the computed forces and moment were slightly off compared to the measured data, the increments due the wall interference effects were predicted reasonably well. The numerical results are also presented on the combined effects of the tunnel sidewall boundary layer and the standoff geometry on the fuselage forebody pressure distributions and the resulting impact on the configuration longitudinal aerodynamic characteristics.

Myo-inositol soft gel capsules may prevent the risk of coffee-induced neural tube defects.

PubMed

De Grazia, Sara; Carlomagno, Gianfranco; Unfer, Vittorio; Cavalli, Pietro

2012-09-01

Neural tube defects (NTDs) are classified as folate sensitive (about 70%) and folate resistant (about 30%); although folic acid is able to prevent the former, several data have shown that inositol may prevent the latter. It has recently been proposed that coffee intake might represent a risk factor for NTD, likely by interfering with the inositol signaling. In the present study, we tested the hypothesis that, beside affecting the inositol signaling pathway, coffee also interferes with inositol absorption. In order to evaluate coffee possible negative effects on inositol gastrointestinal absorption, a single-dose bioavailability trial was conducted. Pharmacokinetics (PK) parameters of myo-inositol (MI) powder and MI soft gelatin capsules swallowed with water and with a single 'espresso' were compared. PK profiles were obtained by analysis of MI plasma concentration, and the respective MI bioavailability was compared. Myo-inositol powder administration was negatively affected by coffee intake, thus suggesting an additional explanation to the interference between inositol deficiency and coffee consumption. On the contrary, the concomitant single 'espresso' consumption did not affect MI absorption following MI soft gelatin capsules administration. Furthermore, it was observed that MI soft gelatin capsule administration resulted in improved bioavailability compared to the MI powder form. Myo-inositol soft gelatin capsules should be considered for the preventive treatment of NTDs in folate-resistant subjects due to their higher bioavailability and to the capability to reduce espresso interference.

Faster forgetting contributes to impaired spatial memory in the PDAPP mouse: Deficit in memory retrieval associated with increased sensitivity to interference?

PubMed Central

Daumas, Stephanie; Sandin, Johan; Chen, Karen S.; Kobayashi, Dione; Tulloch, Jane; Martin, Stephen J.; Games, Dora; Morris, Richard G.M.

2008-01-01

Two experiments were conducted to investigate the possibility of faster forgetting by PDAPP mice (a well-established model of Alzheimer’s disease as reported by Games and colleagues in an earlier paper). Experiment 1, using mice aged 13–16 mo, confirmed the presence of a deficit in a spatial reference memory task in the water maze by hemizygous PDAPP mice relative to littermate controls. However, after overtraining to a criterion of equivalent navigational performance, a series of memory retention tests revealed faster forgetting in the PDAPP group. Very limited retraining was sufficient to reinstate good memory in both groups, indicating that their faster forgetting may be due to retrieval failure rather than trace decay. In Experiment 2, 6-mo-old PDAPP and controls were required to learn each of a series of spatial locations to criterion with their memory assessed 10 min after learning each location. No memory deficit was apparent in the PDAPP mice initially, but a deficit built up through the series of locations suggestive of increased sensitivity to interference. Faster forgetting and increased interference may each reflect a difficulty in accessing memory traces. This interpretation of one aspect of the cognitive deficit in human mutant APP mice has parallels to deficits observed in patients with Alzheimer’s disease, further supporting the validity of transgenic models of the disease. PMID:18772249

Analytical interferences in point-of-care testing glucometers by icodextrin and its metabolites: an overview.

PubMed

Floré, Katelijne M J; Delanghe, Joris R

2009-01-01

Current point-of-care testing (POCT) glucometers are based on various test principles. Two major method groups dominate the market: glucose oxidase-based systems and glucose dehydrogenase-based systems using pyrroloquinoline quinone (GDH-PQQ) as a cofactor. The GDH-PQQ-based glucometers are replacing the older glucose oxidase-based systems because of their lower sensitivity for oxygen. On the other hand, the GDH-PQQ test method results in falsely elevated blood glucose levels in peritoneal dialysis patients receiving solutions containing icodextrin (e.g., Extraneal; Baxter, Brussels, Belgium). Icodextrin is metabolized in the systemic circulation into different glucose polymers, but mainly maltose, which interferes with the GDH-PQQ-based method. Clinicians should be aware of this analytical interference. The POCT glucometers based on the GDH-PQQ method should preferably not be used in this high-risk population and POCT glucose results inconsistent with clinical suspicion of hypoglycemic coma should be retested with another testing system.

Analysis of compounds that interfere with herpes simplex virus-host receptor interactions using surface plasmon resonance.

PubMed

Gopinath, Subash C B; Hayashi, Kyoko; Lee, Jung-Bum; Kamori, Akiko; Dong, Cai-Xia; Hayashi, Toshimitsu; Kumar, Penmetcha K R

2013-11-05

The entry of herpes simplex virus into host cells involves a complex series of events that require concerted inputs from multiple HSV glycoproteins. Among these glycoproteins, the gD protein of HSV-1 and HSV-2 plays an important role for host receptor binding and membrane fusion. In the present study, we evaluated the ability of different sulfated saccharides to interfere with gD-host receptor (HVEM) interactions using our recently reported molecular assay (Gopinath, S. C. B.; Hayashi, K.; Kumar, P. K. R. J. Virol. 2012, 86, 6732-6744). Initially, we tested the ability of heparan sulfate to interfere with the HVEM-HSV-1 gD interaction and found that heparan sulfate is able to interfere efficiently, with an apparent EC50 of 2.1 μM. In addition, we tested different synthetic sulfated polysaccharides and natural sulfated polysaccharides from an edible alga, Sargassum horneri , after fractionation into different sizes and sulfate and uronic acid contents. Six polysaccharides isolated from S. horneri were found to efficiently interfere with the HVEM-gD interaction. Three others caused moderate interference, and five caused weak interference. These results were confirmed with plaque assays, and good agreement was found with the results of the SPR assay for the identification of compounds that interfere with HVEM-HSV-1 gD binding. These studies suggest that our molecular assay based on surface plasmon resonance is not only useful for the analysis of viral-host protein interactions but is also applicable for the routine screening of compounds to identify those that interfere with the first step of viral entry, thus facilitating the rapid development of novel antiviral compounds that target HSV.

Heat transfer phase change paint test (OH-42) of a Rockwell International SSV orbiter in the NASA/LRC Mach 8 variable density wind tunnel

NASA Technical Reports Server (NTRS)

Jones, R.; Creel, T. R., Jr.; Lawing, P.; Quan, M.; Dye, W.; Cummings, J.; Gorowitz, H.; Craig, C.; Rich, G.

1973-01-01

Phase change paint tests of a Rockwell International .00593-scale space shuttle orbiter were conducted in the Langley Research Center's Variable Density Wind Tunnel. The test objectives were to determine the effects of various wing/underbody configurations on the aerodynamic heating rates and boundary layer transition during simulated entry conditions. Several models were constructed. Each varied from the other in either wing cuff radius, airfoil thickness, or wing-fuselage underbody blending. Two ventral fins were glued to the fuselage underside of one model to test the interference heating effects. Simulated Mach 8 entry data were obtained for each configuration at angles of attack ranging from 25 to 40 deg, and a Reynolds number variation of one million to eight million. Elevon, bodyflap, and rudder flare deflections were tested. Oil flow visualization and Schlieren photographs were obtained to aid in reducing the phase change paint data as well as to observe the flow patterns peculiar to each configuration.

Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan

2012-02-15

Highlights: Black-Right-Pointing-Pointer Photoacoustic infrared spectroscopy tested for measuring tracer gas in landfills. Black-Right-Pointing-Pointer Measurement errors for tracer gases were 1-3% in landfill gas. Black-Right-Pointing-Pointer Background signals from landfill gas result in elevated limits of detection. Black-Right-Pointing-Pointer Technique is much less expensive and easier to use than GC. - Abstract: Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobilitymore » and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF{sub 6}), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1-3% in landfill gas but 4-5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3-4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences.« less

Electromagnetic interference of bone-anchored hearing aids by cellular phones.

PubMed

Kompis, M; Negri, S; Häusler, R

2000-10-01

We report a case of electromagnetic interference between a bone-anchored hearing aid (BAHA) and a cellular phone. A 54-year-old women was successfully treated for severe mixed conductive and sensorineural hearing loss with a BAHA. Five years after implantation, the patient experienced a sudden feeling of dizziness, accompanied by a loud buzzing sound and by a sensation of head pressure while examining a digital mobile phone. During a subsequent experiment, the buzzing sound could be reproduced and was identified as electromagnetic interference between the BAHA and digital cellular phones. Seventeen adult BAHA users from our clinic participated in a subsequent survey. Of the 13 patients with some experience of digital cellular phones, 11 reported hearing annoying noises elicited by these devices. However, no other sensation, such as dizziness, was described. Owing to the increasing number of users of both hearing aids and cellular phones, the incidence of electromagnetic interference must be expected to increase as well. Although to date there is no evidence that such interference may be harmful or dangerous to users of conventional or bone-anchored hearing aids, unexpected interference can be a frightening experience.

Analysis of electromagnetic interference from power system processing and transmission components for Space Station Freedom

NASA Technical Reports Server (NTRS)

Barber, Peter W.; Demerdash, Nabeel A. O.; Wang, R.; Hurysz, B.; Luo, Z.

1991-01-01

The goal is to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom.The approach consists of four steps: (1) develop analytical tools (models and computer programs); (2) conduct parameterization studies; (3) predict the global space station EMI environment; and (4) provide a basis for modification of EMI standards.

Electromagnetic Noise Interference and Compatibility

DTIC Science & Technology

1975-11-01

RADIO INTERFERENCE by C.Fengler 7 LES CHARGES ELECTROSTATIQUES ET LES PERTURBATIONS QU’ELLES ENTRAINENT DANS LES LIAISONS RADIOELECTRIQUES par...PAR LA TRANSMISSION DANS UN SYSTFJE INTEGRE AEROPORTE par r,.David et M.Vanneizel 31 Not available at time of priating Reference DIGITAL DATA...TRANSMISSION IN AIRCRAFT: EMC-PROBLEMS AND POSSIBLE SOLUTIONS by R.Rode 32 GENERATIONS El EFFETS DES TENSIONS PARASITES DE CONDUCTION ET DE RAVONNEMENT ENTRE

Hemolysis from a nurses’ standpoint – survey from four Croatian hospitals

PubMed Central

Dorotić, Adrijana; Antončić, Dragana; Biljak, Vanja Radišić; Nedić, Dara; Beletić, Andjelo

2015-01-01

Introduction Hemolysis can occur during sample collection, handling and transport. It is more frequent when the non-laboratory staff performs sampling. The aim of this study was to assess nurses’ knowledge on the causes of hemolysis and consequential impact on the laboratory tests results. Additionally, the differences in knowledge, related to work experience, professional degree and previous education about hemolysis were explored. Materials and methods An anonymus survey, containing 11 questions on demographics, causes of hemolysis, its impact on biochemical parameters and nurses’ attitude towards additional education in preanalytics, was conducted in four Croatian hospitals. The answers were compared by Chi-squared and Fischer exact test. Results In total, 562 survey results were collected. Majority of nurses declared familiarity with the term “hemolysis” (99.6%). There were 77% of correct answers regarding questions about the causes of hemolysis, but only 50% when it comes to questions about interference in biochemical tests. The percentage of correct answers about causes was significantly lower (P = 0.029) among more experienced nurses, and higher (P = 0.027) in those with higher professional degree, while influence of previous education was not significant. Also, higher percentage of correct answers about interferences was encountered in nurses with longer work experience (P = 0.039). More than 70% of nurses declared that additional education about preanalytical factors would be beneficial. Conclusion Croatian nurses are familiar with the definition of hemolysis, but a lack of knowledge about causes and influence on laboratory test results is evident. Nurses are eager to improve their knowledge in this field of preanalytical phase. PMID:26525069

Interference in Ballistic Motor Learning: Specificity and Role of Sensory Error Signals

PubMed Central

Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C.; Nielsen, Jens Bo

2011-01-01

Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity in overlapping circuits and predicted specificity. To test this, subjects learned a ballistic motor task. Interference was observed following subsequent learning of an accuracy-tracking task, but only if the competing task involved the same muscles and movement direction. Interference was not observed from a non-learning task suggesting that interference requires competing learning. Subsequent learning of the competing task 4 h after initial learning did not cause interference suggesting disruption of early motor memory consolidation as one possible mechanism underlying interference. Repeated transcranial magnetic stimulation (rTMS) of corticospinal motor output at intensities below movement threshold did not cause interference, whereas suprathreshold rTMS evoking motor responses and (re)afferent activation did. Finally, the experiments revealed that suprathreshold repetitive electrical stimulation of the agonist (but not antagonist) peripheral nerve caused interference. The present study is, to our knowledge, the first to demonstrate that peripheral nerve stimulation may cause interference. The finding underscores the importance of sensory feedback as error signals in motor learning. We conclude that interference requires competing plasticity in overlapping circuits. Interference is remarkably specific for circuits involved in a specific movement and it may relate to sensory error signals. PMID:21408054

An experimental investigation of three dimensional low speed minimum interference wind tunnel for high lift wings

NASA Technical Reports Server (NTRS)

Shindo, S.; Joppa, R. G.

1980-01-01

As a means to achieve a minimum interference correction wind tunnel, a partially actively controlled test section was experimentally examined. A jet flapped wing with 0.91 m (36 in) span and R = 4.05 was used as a model to create moderately high lift coefficients. The partially controlled test section was simulated using an insert, a rectangular box 0.96 x 1.44 m (3.14 x 4.71 ft) open on both ends in the direction of the tunnel air flow, placed in the University of Washington Aeronautical Laboratories (UWAL) 2.44 x 3.66 m (8 x 12 ft) wind tunnel. A tail located three chords behind the wing was used to measure the downwash at the tail region. The experimental data indicates that, within the range of momentum coefficient examined, it appears to be unnecessary to actively control all four sides of the test section walls in order to achieve the near interference free flow field environment in a small wind tunnel. The remaining wall interference can be satisfactorily corrected by the vortex lattice method.

Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

NASA Technical Reports Server (NTRS)

Sherman, Albert

1939-01-01

An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment to the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angel and as losses in the tail. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for a complete combination.

41 CFR 102-74.555 - What rules of conduct must all permittees observe while on Federal property?

Code of Federal Regulations, 2011 CFR

2011-01-01

..., age, color, disability, sex, or national origin in conducting activities; (d) Not distribute any item... activities that would interfere with the preferences afforded blind licensees under the Randolph-Sheppard Act...

41 CFR 102-74.555 - What rules of conduct must all permittees observe while on Federal property?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., age, color, disability, sex, or national origin in conducting activities; (d) Not distribute any item... activities that would interfere with the preferences afforded blind licensees under the Randolph-Sheppard Act...

41 CFR 102-74.555 - What rules of conduct must all permittees observe while on Federal property?

Code of Federal Regulations, 2012 CFR

2012-01-01

..., age, color, disability, sex, or national origin in conducting activities; (d) Not distribute any item... activities that would interfere with the preferences afforded blind licensees under the Randolph-Sheppard Act...

41 CFR 102-74.555 - What rules of conduct must all permittees observe while on Federal property?

Code of Federal Regulations, 2014 CFR

2014-01-01

..., age, color, disability, sex, or national origin in conducting activities; (d) Not distribute any item... activities that would interfere with the preferences afforded blind licensees under the Randolph-Sheppard Act...

Potential for palivizumab interference with commercially available antibody-antigen based respiratory syncytial virus diagnostic assays.

PubMed

Deming, Damon J; Patel, Nita; McCarthy, Michael P; Mishra, Lalji; Shapiro, Alan M; Suzich, JoAnn A

2013-10-01

Palivizumab is a monoclonal antibody indicated for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus infection in infants. The potential for palivizumab to interfere with commercially available respiratory syncytial virus diagnostic tests was demonstrated. Negative test results in palivizumab-treated subjects should be interpreted with caution and confirmed by a nucleic acid amplification-based assay.

The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

ERIC Educational Resources Information Center

Oberauer, Klaus; Awh, Edward; Sutterer, David W.

2017-01-01

We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

Proactive Interference and Directed Forgetting in Short-Term Motor Memory

ERIC Educational Resources Information Center

Burwitz, Leslie

1974-01-01

The present study was designed to test the effect of instructions to forget prior motor learning and the results were relevant to the understanding of short-term motor memory (STMM) proactive interference (PI). (Author/RK)

The likelihood of acetone interference in breath alcohol measurement

DOT National Transportation Integrated Search

1985-09-01

This report discusses the significance of possible interference of acetone in breath alcohol testing. The following dimensions were considered: 1) what levels of acetone concentration may appear on the breath; 2) what levels of acetone concentration ...

Observation of Genuine Three-Photon Interference

NASA Astrophysics Data System (ADS)

Agne, Sascha; Kauten, Thomas; Jin, Jeongwan; Meyer-Scott, Evan; Salvail, Jeff Z.; Hamel, Deny R.; Resch, Kevin J.; Weihs, Gregor; Jennewein, Thomas

2017-04-01

Multiparticle quantum interference is critical for our understanding and exploitation of quantum information, and for fundamental tests of quantum mechanics. A remarkable example of multi-partite correlations is exhibited by the Greenberger-Horne-Zeilinger (GHZ) state. In a GHZ state, three particles are correlated while no pairwise correlation is found. The manifestation of these strong correlations in an interferometric setting has been studied theoretically since 1990 but no three-photon GHZ interferometer has been realized experimentally. Here we demonstrate three-photon interference that does not originate from two-photon or single photon interference. We observe phase-dependent variation of three-photon coincidences with (92.7 ±4.6 )% visibility in a generalized Franson interferometer using energy-time entangled photon triplets. The demonstration of these strong correlations in an interferometric setting provides new avenues for multiphoton interferometry, fundamental tests of quantum mechanics, and quantum information applications in higher dimensions.

Allelopathic inhibition ofCynodon dactylon (L.) pers. and other plant species byEuphorbia prostrata L.

PubMed

Alsaadawi, I S; Sakeri, F A; Al-Dulaimy, S M

1990-09-01

Field observations indicated thatEuphorbia prostrata strongly interferes withCynodon dactylon (L.) Pers. Analysis of some physical and chemical soil factors indicated that competition was not the dominant factor of that interference. Soil collected from underE. prostrata stands was very inhibitory to seed germination and seeding growth of some of the test species including C.Dactylon. This suggests the presence of inhibitory compounds in soil ofE. prostrata stands. Subsequent experiments showed that aqueous extract, decaying residues, and root exudates ofE. prostrata were inhibitory to most of the test species including C.Dactylon. Thus, it appears that allelopathy is the major component of the interference, with competition probably accentuating its effect. It also was found that allelopathy is an important component of the interference byE. prostrata againstAmaranthus retroflexus, Medicago sativa, andGossypium hirsutum.

Lipemia interferences in routine clinical biochemical tests.

PubMed

Calmarza, Pilar; Cordero, José

2011-01-01

Lipemic specimens are a common and frequent, but yet unresolved problem in clinical chemistry, and may produce significant interferences in the analytical results of different biochemical parameters. The aim of this study was to examine the effect of lipid removal using ultracentrifugation of lipemic samples, on some routine biochemistry parameters. Among all the samples obtained daily in our laboratory, the ones which were visibly muddy were selected and underwent to a process of ultracentrifugation, being determined a variety of biochemical tests before and after ultracentrifugation. A total of 110 samples were studied. We found significant differences in all the parameters studied except for total bilirubin, glucose, gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST). The greatest differences in the parameters analyzed were found in the concentration of alanine aminotransferase (ALT) (7.36%) and the smallest ones in the concentration of glucose (0.014%). Clinically significant interferences were found for phosphorus, creatinine, total protein and calcium. Lipemia causes clinically significant interferences for phosphorus, creatinine, total protein and calcium measurement and those interferences could be effectively removed by ultracentrifugation.

Work-home interference among nurses: reciprocal relationships with job demands and health.

PubMed

van der Heijden, Beatrice I J M; Demerouti, Evangelia; Bakker, Arnold B

2008-06-01

This paper is a report of a study with three aims: (i) to investigate whether emotional, quantitative and physical demands have a causal, negative impact on nurses' health; (ii) to examine whether work-home interference can explain this effect, by playing a mediating role; and (iii) to test the so-called loss spiral hypothesis claiming that nurses' health problems lead to even higher job demands and more work-home interference over time. While many scholars have thought in terms of the stressor-->work-home interference-->strain model, the validity of a model that includes opposite pathways needs to be tested. A questionnaire was completed twice, with a 1-year time interval by 753 (63.4%) Registered Nurses working in hospitals, 183 (15.4%) working in nursing homes, and 251 (21.1%) working in home care institutions. The first measurement took place between October 2002 and June 2003. Our findings strongly support the idea of cross-lagged, reciprocal relationships between job demands and general health over time. The reciprocal model with work-home interference as an intervening variable (including reciprocal relationships between job demands, work-home interference and general health) showed a good fit to the data, and proved to be superior to both the causality and reversed causation models. The higher nurses' job demands, the higher is their level of work-home interference and the more likely is a general health deterioration over time, in turn giving rise to higher job demands and work-home interference, which may even aggravate the nurses' general health, and so on.

Evaluation of the Relationship between Brain-Derived Neurotropic Factor Levels and the Stroop Interference Effect in Children with Attention-Deficit Hyperactivity Disorder.

PubMed

Şimşek, Şeref; Gençoğlan, Salih; Yüksel, Tuğba; Kaplan, İbrahim; Aktaş, Hüseyin; Alaca, Rümeysa

2016-12-01

Brain-derived neurotropic factor (BDNF) has been suggested to play a role in the pathogenesis of attention-deficit hyperactivity disorder (ADHD). In addition, impairment in executive functions has been reported in children with ADHD. This study investigated the presence of a relationship between Stroop test scores and BDNF levels in children with ADHD. The study was conducted in the Department of Child Psychiatry at Dicle University. The study included 49 children between 6 and 15 years of age (M/F: 42/7), who were diagnosed with ADHD according to DSM-IV, and who did not receive previous therapy. Similar in terms of age and gender to the ADHD group, 40 children were selected in the control group. The Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version was administered to all participants. Parents and teachers were administered Turgay DSM-IV-based Child and Adolescent Behavior Disorders Screening and Rating Scale to measure symptom severity in children with ADHD. Children with ADHD underwent the Stroop test. BDNF levels were evaluated in serum by ELISA. The ADHD and control groups did not differ in terms of BDNF levels. BDNF levels did not differ between ADHD subtypes. There was also no relationship between the Stroop test interference scores and BDNF levels. The findings of the present study are in line with those in studies that demonstrated no significant role of BDNF in the pathogenesis of ADHD.

Aerodynamic characteristics of a high-wing transport configuration with a over-the-wing nacelle-pylon arrangement

NASA Technical Reports Server (NTRS)

Henderson, W. P.; Abeyounis, W. K.

1985-01-01

An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects on the aerodynamic characteristics of a high-wing transport configuration of installing an over-the-wing nacelle-pylon arrangement. The tests are conducted at Mach numbers from 0.70 to 0.82 and at angles of attack from -2 deg to 4 deg. The configurational variables under study include symmetrical and contoured nacelles and pylons, pylon size, and wing leading-edge extensions. The symmetrical nacelles and pylons reduce the lift coefficient, increase the drag coefficient, and cause a nose-up pitching-moment coefficient. The contoured nacelles significantly reduce the interference drag, though it is still excessive. Increasing the pylon size reduces the drag, whereas adding wing leading-edge extension does not affect the aerodynamic characteristics significantly.

The role of long-term memory in a test of visual working memory: Proactive facilitation but no proactive interference.

PubMed

Oberauer, Klaus; Awh, Edward; Sutterer, David W

2017-01-01

We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3 concrete objects in an array. Each array in the WM test consisted of 1 old (previously learned) object with a new color (old-mismatch), 1 old object with its old color (old-match), and 1 new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from LTM. In the old-mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The protective effects of acute cardiovascular exercise on the interference of procedural memory.

PubMed

Jo, J S; Chen, J; Riechman, S; Roig, M; Wright, D L

2018-04-10

Numerous studies have reported a positive impact of acute exercise for procedural skill memory. Previous work has revealed this effect, but these findings are confounded by a potential contribution of a night of sleep to the reported exercise-mediated reduction in interference. Thus, it remains unclear if exposure to a brief bout of exercise can provide protection to a newly acquired motor memory. The primary objective of the present study was to examine if a single bout of moderate-intensity cardiovascular exercise after practice of a novel motor sequence reduces the susceptibility to retroactive interference. To address this shortcoming, 17 individuals in a control condition practiced a novel motor sequence that was followed by test after a 6-h wake-filled interval. A separate group of 17 individuals experienced practice with an interfering motor sequence 45 min after practice with the original sequence and were then administered test trials 6 h later. One additional group of 12 participants was exposed to an acute bout of exercise immediately after practice with the original motor sequence but prior to practice with the interfering motor sequence and the subsequent test. In comparison with the control condition, increased response times were revealed during the 6-h test for the individuals that were exposed to interference. The introduction of an acute bout of exercise between the practice of the two motor sequences produced a reduction in interference from practice with the second task at the time of test, however, this effect was not statistically significant. These data reinforce the hypothesis that while there may be a contribution from exercise to post-practice consolidation of procedural skills which is independent of sleep, sleep may interact with exercise to strengthen the effects of the latter on procedural memory.

Mutual interferences and design principles for mechatronic devices in magnetic resonance imaging.

PubMed

Yu, Ningbo; Gassert, Roger; Riener, Robert

2011-07-01

Robotic and mechatronic devices that work compatibly with magnetic resonance imaging (MRI) are applied in diagnostic MRI, image-guided surgery, neurorehabilitation and neuroscience. MRI-compatible mechatronic systems must address the challenges imposed by the scanner's electromagnetic fields. We have developed objective quantitative evaluation criteria for device characteristics needed to formulate design guidelines that ensure MRI-compatibility based on safety, device functionality and image quality. The mutual interferences between an MRI system and mechatronic devices working in its vicinity are modeled and tested. For each interference, the involved components are listed, and a numerical measure for "MRI-compatibility" is proposed. These interferences are categorized into an MRI-compatibility matrix, with each element representing possible interactions between one part of the mechatronic system and one component of the electromagnetic fields. Based on this formulation, design principles for MRI-compatible mechatronic systems are proposed. Furthermore, test methods are developed to examine whether a mechatronic device indeed works without interferences within an MRI system. Finally, the proposed MRI-compatibility criteria and design guidelines have been applied to an actual design process that has been validated by the test procedures. Objective and quantitative MRI-compatibility measures for mechatronic and robotic devices have been established. Applying the proposed design principles, potential problems in safety, device functionality and image quality can be considered in the design phase to ensure that the mechatronic system will fulfill the MRI-compatibility criteria. New guidelines and test procedures for MRI instrument compatibility provide a rational basis for design and evaluation of mechatronic devices in various MRI applications. Designers can apply these criteria and use the tests, so that MRI-compatibility results can accrue to build an experiential database.

A wall interference assessment/correction interface measurement system for the NASA/ARC 12-ft PWT

NASA Technical Reports Server (NTRS)

1989-01-01

Development of complex air vehicle configurations is placing increasing demands on wind tunnel testing capabilities. A major area of concern is wall induced interference. Recent developments in wall interference technology provide a means for assessing and correcting for the wall induced interference using information contained in the distribution of flow variables measured at, or near, the wall. The restoration of the NASA-ARC 12-ft pressure wind tunnel (PWT) provides an opportunity to incorporate a measurement system with which wall interference assessment/correction (WIAC) technology can be applied. In this first phase of the development of a WIAC system for the PWT, the design criteria for the placement and the geometry of wall static pressure orifices were determined with a three step approach. First, the operational environment of the PWT was analyzed as to the requirements for the WIAC system. Second, appropriate wall interference theories were evaluated against the requirements determined from the operational environment. Third, the flow about representative models in the PWT was calculated and, specifically, the pressure signatures at the location of the test section wall were obtained. The number of discrete pressure measurements and their locations were determined by curve fitting the pressure distribution through the discrete measurements and evaluating the resulting error.

Binaural Interference: Quo Vadis?

PubMed

Jerger, James; Silman, Shlomo; Silverman, Carol; Emmer, Michele

2017-04-01

The reality of the phenomenon of binaural interference with speech recognition has been debated for two decades. Research has taken one of two avenues; group studies or case reports. In group studies, a sample of the elderly population is tested on speech recognition under three conditions; binaural, monaural right and monaural left. The aim is to determine the percent of the sample in which the expected outcome (binaural score-better-than-either-monaural score) is reversed (i.e., one of the monaural scores is better than the binaural score). This outcome has been commonly used to define binaural interference. The object of group studies is to answer the "how many" question, what is the prevalence of binaural interference in the sample. In case reports the binaural interference conclusion suggested by the speech recognition tests is not accepted until it has been corroborated by other independent diagnostic audiological measures. The aim is to attempt to determine the basis for the findings, to answer the "why" question. This article is at once tutorial, editorial and a case report. We argue that it is time to accept the reality of the phenomenon of binaural interference, to eschew group statistical approaches in search of an answer to the "how many" question, and to focus on individual case reports in search of an answer to the "why" question. American Academy of Audiology.

When Learning Disturbs Memory – Temporal Profile of Retroactive Interference of Learning on Memory Formation

PubMed Central

Sosic-Vasic, Zrinka; Hille, Katrin; Kröner, Julia; Spitzer, Manfred; Kornmeier, Jürgen

2018-01-01

Introduction: Consolidation is defined as the time necessary for memory stabilization after learning. In the present study we focused on effects of interference during the first 12 consolidation minutes after learning. Participants had to learn a set of German – Japanese word pairs in an initial learning task and a different set of German – Japanese word pairs in a subsequent interference task. The interference task started in different experimental conditions at different time points (0, 3, 6, and 9 min) after the learning task and was followed by subsequent cued recall tests. In a control experiment the interference periods were replaced by rest periods without any interference. Results: The interference task decreased memory performance by up to 20%, with negative effects at all interference time points and large variability between participants concerning both the time point and the size of maximal interference. Further, fast learners seem to be more affected by interference than slow learners. Discussion: Our results indicate that the first 12 min after learning are highly important for memory consolidation, without a general pattern concerning the precise time point of maximal interference across individuals. This finding raises doubts about the generalized learning recipes and calls for individuality of learning schedules. PMID:29503621

B-1 AFT Nacelle Flow Visualization Study

NASA Technical Reports Server (NTRS)

Celniker, Robert

1975-01-01

A 2-month program was conducted to perform engineering evaluation and design tasks to prepare for visualization and photography of the airflow along the aft portion of the B-1 nacelles and nozzles during flight test. Several methods of visualizing the flow were investigated and compared with respect to cost, impact of the device on the flow patterns, suitability for use in the flight environment, and operability throughout the flight. Data were based on a literature search and discussions with the test personnel. Tufts were selected as the flow visualization device in preference to several other devices studied. A tuft installation pattern has been prepared for the right-hand aft nacelle area of B-1 air vehicle No.2. Flight research programs to develop flow visualization devices other than tufts for use in future testing are recommended. A design study was conducted to select a suitable motion picture camera, to select the camera location, and to prepare engineering drawings sufficient to permit installation of the camera. Ten locations on the air vehicle were evaluated before the selection of the location in the horizontal stabilizer actuator fairing. The considerations included cost, camera angle, available volume, environmental control, flutter impact, and interference with antennas or other instrumentation.

Interference of daratumumab with pretransfusion testing, mimicking a high-titer, low avidity like antibody.

PubMed

Lin, Mei-Hwa; Liu, Fei-Yun; Wang, Hsiu-Mien; Cho, Hsin-Ching; Lo, Shyh-Chyi

2017-01-01

Daratumumab is a monoclonal immunoglobulin against CD38 and has been approved for treating patients with refractory multiple myeloma. The presence of daratumumab in the sera can interfere with pretransfusion testing due to the weakly expression of CD38 on red cells. The reactivity could be mistaken as autoantibody (if autocontrol is positive) or alloantibody (if autocontrol is negative). We present a case that demonstrates daratumumab could mimic a high titer low avidity (HTLA) alloantibody. A 34-year-old male patient of refractory myeloma was recruited in phase three clinical trial involving daratumumab. Samples were sent to the blood bank for pretransfusion testing. Without knowledge of patient having used daratumumab, we mistook the reactivity in the patient's sera as an HTLA antibody due to the results of negative autocontrol and high titers of antibody activity. Antibody screen showed a panreactive pattern and the reactivity against screening cells was up to a titer of 1: 1240. The reactivity was weaker against cord cells than adult cells, became weaker against ZZAP-treated cells and became negative against DDT-treated cells. A discussion with attending physician finally revealed the reactivity was due to the interference caused by daratumumab. The case demonstrates good communication is essential in performing pretransfusion testing for patients receiving daratumumab and other new biological regimens that can interfere with compatibility test.

Interference of daratumumab with pretransfusion testing, mimicking a high-titer, low avidity like antibody

PubMed Central

Lin, Mei-Hwa; Liu, Fei-Yun; Wang, Hsiu-Mien; Cho, Hsin-Ching; Lo, Shyh-Chyi

2017-01-01

Daratumumab is a monoclonal immunoglobulin against CD38 and has been approved for treating patients with refractory multiple myeloma. The presence of daratumumab in the sera can interfere with pretransfusion testing due to the weakly expression of CD38 on red cells. The reactivity could be mistaken as autoantibody (if autocontrol is positive) or alloantibody (if autocontrol is negative). We present a case that demonstrates daratumumab could mimic a high titer low avidity (HTLA) alloantibody. A 34-year-old male patient of refractory myeloma was recruited in phase three clinical trial involving daratumumab. Samples were sent to the blood bank for pretransfusion testing. Without knowledge of patient having used daratumumab, we mistook the reactivity in the patient's sera as an HTLA antibody due to the results of negative autocontrol and high titers of antibody activity. Antibody screen showed a panreactive pattern and the reactivity against screening cells was up to a titer of 1: 1240. The reactivity was weaker against cord cells than adult cells, became weaker against ZZAP-treated cells and became negative against DDT-treated cells. A discussion with attending physician finally revealed the reactivity was due to the interference caused by daratumumab. The case demonstrates good communication is essential in performing pretransfusion testing for patients receiving daratumumab and other new biological regimens that can interfere with compatibility test. PMID:28970695

Obtaining tight bounds on higher-order interferences with a 5-path interferometer

NASA Astrophysics Data System (ADS)

Kauten, Thomas; Keil, Robert; Kaufmann, Thomas; Pressl, Benedikt; Brukner, Časlav; Weihs, Gregor

2017-03-01

Within the established theoretical framework of quantum mechanics, interference always occurs between pairs of paths through an interferometer. Higher order interferences with multiple constituents are excluded by Born’s rule and can only exist in generalized probabilistic theories. Thus, high-precision experiments searching for such higher order interferences are a powerful method to distinguish between quantum mechanics and more general theories. Here, we perform such a test in an optical multi-path interferometer, which avoids crucial systematic errors, has access to the entire phase space and is more stable than previous experiments. Our results are in accordance with quantum mechanics and rule out the existence of higher order interference terms in optical interferometry to an extent that is more than four orders of magnitude smaller than the expected pairwise interference, refining previous bounds by two orders of magnitude.

Aharanov-Bohm quantum interference in a reconfigurable electron system

NASA Astrophysics Data System (ADS)

Irvin, P.; Lu, S.; Annadi, A.; Cheng, G.; Tomczyk, M.; Huang, M.; Levy, J.; Lee, J.-W.; Lee, H.; Eom, C.-B.

Aharanov-Bohm (AB) interference can arise in transport experiments when magnetic flux threads through two or more transport channels. The existence of this behavior requires long-range ballistic transport and is typically observed only in exceptionally clean materials. We observe AB interference in wide (w 100 nm) channels created at the LaAlO3/SrTiO3 interface using conductive AFM lithography. Interference occurs above a critical field B 4 T and increases in magnitude with increasing magnetic field. The period of oscillation implies a ballistic length that greatly exceeds the micron-scale length of the channel, consistent with Fabry-Perot interference in 1D channels. The conditions under which AB oscillations are observed will be discussed in the context of the electron pairing mechanism in LaAlO3/SrTiO3. We gratefully acknowledge financial support from AFOSR FA9550-12-1-0342 (CBE), NSF DMR-1234096 (CBE), and ONR N00014-15-1-2847 (JL).

Wall-interference assessment and corrections for transonic NACA 0012 airfoil data from various wind tunnels. M.S. Thesis - George Washington Univ., 1988

NASA Technical Reports Server (NTRS)

Green, Lawrence L.; Newman, Perry A.

1991-01-01

A nonlinear, four wall, post-test wall interference assessment/correction (WIAC) code was developed for transonic airfoil data from solid wall wind tunnels with flexibly adaptable top and bottom walls. The WIAC code was applied over a broad range of test conditions to four sets of NACA 0012 airfoil data, from two different adaptive wall wind tunnels. The data include many test points for fully adapted walls, as well as numerous partially adapted and unadapted test points, which together represent many different model/tunnel configurations and possible wall interference effects. Small corrections to the measured Mach numbers and angles of attack were obtained from the WIAC code even for fully adapted data; these corrections generally improve the correlation among the various sets of airfoil data and simultaneously improve the correlation of the data with calculations for a 2-D, free air, Navier-Stokes code. The WIAC corrections for airfoil data taken in fully adapted wall test sections are shown to be significantly smaller than those for comparable airfoil data from straight, slotted wall test sections. This indicates, as expected, a lesser degree of wall interference in the adapted wall tunnels relative to the slotted wall tunnels. Application of the WIAC code to this data was, however, somewhat more difficult and time consuming than initially expected from similar previous experience with WIAC applications to slotted wall data.

Different Loci of Semantic Interference in Picture Naming vs. Word-Picture Matching Tasks.

PubMed

Harvey, Denise Y; Schnur, Tatiana T

2016-01-01

Naming pictures and matching words to pictures belonging to the same semantic category impairs performance relative to when stimuli come from different semantic categories (i.e., semantic interference). Despite similar semantic interference phenomena in both picture naming and word-picture matching tasks, the locus of interference has been attributed to different levels of the language system - lexical in naming and semantic in word-picture matching. Although both tasks involve access to shared semantic representations, the extent to which interference originates and/or has its locus at a shared level remains unclear, as these effects are often investigated in isolation. We manipulated semantic context in cyclical picture naming and word-picture matching tasks, and tested whether factors tapping semantic-level (generalization of interference to novel category items) and lexical-level processes (interactions with lexical frequency) affected the magnitude of interference, while also assessing whether interference occurs at a shared processing level(s) (transfer of interference across tasks). We found that semantic interference in naming was sensitive to both semantic- and lexical-level processes (i.e., larger interference for novel vs. old and low- vs. high-frequency stimuli), consistent with a semantically mediated lexical locus. Interference in word-picture matching exhibited stable interference for old and novel stimuli and did not interact with lexical frequency. Further, interference transferred from word-picture matching to naming. Together, these experiments provide evidence to suggest that semantic interference in both tasks originates at a shared processing stage (presumably at the semantic level), but that it exerts its effect at different loci when naming pictures vs. matching words to pictures.

Different Loci of Semantic Interference in Picture Naming vs. Word-Picture Matching Tasks

PubMed Central

Harvey, Denise Y.; Schnur, Tatiana T.

2016-01-01

Naming pictures and matching words to pictures belonging to the same semantic category impairs performance relative to when stimuli come from different semantic categories (i.e., semantic interference). Despite similar semantic interference phenomena in both picture naming and word-picture matching tasks, the locus of interference has been attributed to different levels of the language system – lexical in naming and semantic in word-picture matching. Although both tasks involve access to shared semantic representations, the extent to which interference originates and/or has its locus at a shared level remains unclear, as these effects are often investigated in isolation. We manipulated semantic context in cyclical picture naming and word-picture matching tasks, and tested whether factors tapping semantic-level (generalization of interference to novel category items) and lexical-level processes (interactions with lexical frequency) affected the magnitude of interference, while also assessing whether interference occurs at a shared processing level(s) (transfer of interference across tasks). We found that semantic interference in naming was sensitive to both semantic- and lexical-level processes (i.e., larger interference for novel vs. old and low- vs. high-frequency stimuli), consistent with a semantically mediated lexical locus. Interference in word-picture matching exhibited stable interference for old and novel stimuli and did not interact with lexical frequency. Further, interference transferred from word-picture matching to naming. Together, these experiments provide evidence to suggest that semantic interference in both tasks originates at a shared processing stage (presumably at the semantic level), but that it exerts its effect at different loci when naming pictures vs. matching words to pictures. PMID:27242621

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deline, Chris; Dann, Geoff

Recent increases in photovoltaic (PV) systems on Department of the Navy (DON) land and potential siting near airfields prompted Commander, Naval Installations Command to fund the Naval Facilities Engineering Command to evaluate the impact of electromagnetic interference (EMI) from PV systems on airfield electronic equipment. Naval Facilities Engineering and Expeditionary Warfare Center tasked Department of Energy National Renewable Energy laboratory (NREL) to conduct the assessment. PV systems often include high-speed switching semiconductor circuits to convert the voltage produced by the PV arrays to the voltage needed by the end user. Switching circuits inherently produce electromagnetic radiation at harmonics of themore » switching frequency. In this report, existing literature is summarized and tests to measure emissions and mitigation methods are discussed. The literature shows that the emissions from typical PV systems are low strength and unlikely to cause interference to most airfield electronic systems. With diligent procurement and siting of PV systems, including specifications for FCC Part 15 Class A compliant equipment and a 250-foot setback from communication equipment, NREL anticipates little to no EMI impact on nearby communications or telemetry equipment.« less

Anomalous aging of EPDM and FEPM under combined thermo-oxidative and hydrolytic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redline, Erica M.; Celina, Mathias C.; Harris, Charles E.

Previous observation of EPDM and FEPM materials aged in thermo-oxidative and thermo-oxidative plus hydrolytic environments revealed an unusual trend: the degradation and disintegration of these polymers in the former case but the ability to maintain mechanical performance and shape in the latter. No abnormalities were observed in the chemical (oxidation rates, FTIR spectra, solvent uptake, gel content, and weight loss vs. temperature) or physical (modulus profile) measurements that could explain these empirically observed aging differences. A second controlled aging test was conducted to verify this trend using only EPDM. Once again it was shown that thermo-oxidative conditions appear to causemore » more degradative damage (enhanced embrittlement) than observed for the combined thermo-oxidative plus hydrolytic environments. From these data we conclude that water may favorably interfere with normal thermo-oxidative degradation processes. This interference may occur via some combination of chemical and physical property changes in the presence of steam such as: oxidation rate and O 2 permeability changes, additional sensitivity to hydrolytic damage, and/or mechanistic changes in relation to pH and hydroperoxide formation.« less

Anomalous aging of EPDM and FEPM under combined thermo-oxidative and hydrolytic conditions

DOE PAGES

Redline, Erica M.; Celina, Mathias C.; Harris, Charles E.; ...

2017-09-15

Previous observation of EPDM and FEPM materials aged in thermo-oxidative and thermo-oxidative plus hydrolytic environments revealed an unusual trend: the degradation and disintegration of these polymers in the former case but the ability to maintain mechanical performance and shape in the latter. No abnormalities were observed in the chemical (oxidation rates, FTIR spectra, solvent uptake, gel content, and weight loss vs. temperature) or physical (modulus profile) measurements that could explain these empirically observed aging differences. A second controlled aging test was conducted to verify this trend using only EPDM. Once again it was shown that thermo-oxidative conditions appear to causemore » more degradative damage (enhanced embrittlement) than observed for the combined thermo-oxidative plus hydrolytic environments. From these data we conclude that water may favorably interfere with normal thermo-oxidative degradation processes. This interference may occur via some combination of chemical and physical property changes in the presence of steam such as: oxidation rate and O 2 permeability changes, additional sensitivity to hydrolytic damage, and/or mechanistic changes in relation to pH and hydroperoxide formation.« less

Signal processing techniques for the U.S. Army Research Laboratory stepped frequency ultra-wideband radar

NASA Astrophysics Data System (ADS)

Nguyen, Lam

2017-05-01

The U.S. Army Research Laboratory (ARL) recently designed and tested a new prototype radar, the Spectrally Agile Frequency-Incrementing Reconfigurable (SAFIRE) radar system, based on a stepped-frequency architecture to address issues associated with our previous impulse-based radars. This is a low-frequency ultra-wideband (UWB) radar with frequencies spanning from 300 to 2000 MHz. Mounted on a vehicle, the radar can be configured in either sidelooking or forward-looking synthetic aperture radar (SAR) mode. We recently conducted our first experiment at Yuma Proving Grounds (YPG). This paper summarizes the radar configurations, parameters, and SAR geometry. The radar data and other noise sources, to include the self-interference signals and radio-frequency interference (RFI) noise sources, are presented and characterized in both the raw (pre-focus) and SAR imagery domains. This paper also describes our signal processing techniques for extracting noise from radar data, as well as the SAR imaging algorithms for forming SAR imagery in both forward- and side-looking modes. Finally, this paper demonstrates our spectral recovery technique and results for a radar operating in a spectrally restricted environment.

Proactive Interference Does Not Meaningfully Distort Visual Working Memory Capacity Estimates in the Canonical Change Detection Task

PubMed Central

Lin, Po-Han; Luck, Steven J.

2012-01-01

The change detection task has become a standard method for estimating the storage capacity of visual working memory. Most researchers assume that this task isolates the properties of an active short-term storage system that can be dissociated from long-term memory systems. However, long-term memory storage may influence performance on this task. In particular, memory traces from previous trials may create proactive interference that sometimes leads to errors, thereby reducing estimated capacity. Consequently, the capacity of visual working memory may be higher than is usually thought, and correlations between capacity and other measures of cognition may reflect individual differences in proactive interference rather than individual differences in the capacity of the short-term storage system. Indeed, previous research has shown that change detection performance can be influenced by proactive interference under some conditions. The purpose of the present study was to determine whether the canonical version of the change detection task – in which the to-be-remembered information consists of simple, briefly presented features – is influenced by proactive interference. Two experiments were conducted using methods that ordinarily produce substantial evidence of proactive interference, but no proactive interference was observed. Thus, the canonical version of the change detection task can be used to assess visual working memory capacity with no meaningful influence of proactive interference. PMID:22403556

Proactive interference does not meaningfully distort visual working memory capacity estimates in the canonical change detection task.

PubMed

Lin, Po-Han; Luck, Steven J

2012-01-01

The change detection task has become a standard method for estimating the storage capacity of visual working memory. Most researchers assume that this task isolates the properties of an active short-term storage system that can be dissociated from long-term memory systems. However, long-term memory storage may influence performance on this task. In particular, memory traces from previous trials may create proactive interference that sometimes leads to errors, thereby reducing estimated capacity. Consequently, the capacity of visual working memory may be higher than is usually thought, and correlations between capacity and other measures of cognition may reflect individual differences in proactive interference rather than individual differences in the capacity of the short-term storage system. Indeed, previous research has shown that change detection performance can be influenced by proactive interference under some conditions. The purpose of the present study was to determine whether the canonical version of the change detection task - in which the to-be-remembered information consists of simple, briefly presented features - is influenced by proactive interference. Two experiments were conducted using methods that ordinarily produce substantial evidence of proactive interference, but no proactive interference was observed. Thus, the canonical version of the change detection task can be used to assess visual working memory capacity with no meaningful influence of proactive interference.

The effect of screw taper on interference fit during load to failure at the soft tissue/bone interface.

PubMed

Mann, Charles J; Costi, John J; Stanley, Richard M; Dobson, Peter J

2005-10-01

The effect of screw geometry on the pullout strength of an anterior cruciate ligament reconstruction is well documented. The effect of a truly tapered screw has not been previously investigated. Thirty bovine knees in right and left knee pairs were collected. Superficial digital flexors from the hind legs of sheep were harvested to form a quadruple tendon graft. For each knee pair, one tendon graft was fixed using a tapered screw (n=15) and the other with a non-tapered screw (n=15). Interference screws were manufactured from stainless steel, and apart from the tapered or non-tapered profile were identical. The screws were inserted into a tibial tunnel already containing the tendon graft. The interference fit was tested by extensile load to failure tests. The insertion torque of the screws and first sign of load to failure (by pullout) of the interference fit were recorded. Results were analysed using paired t-tests. The results indicated that tapered screws have significantly higher resistance to interference failure (p=0.007) and insertion torque (p<0.001) than non-tapered screws. The improved biomechanical performance of tapered screws demonstrated in this study may translate into superior clinical results, particularly at the tibial attachment of hamstring anterior cruciate ligament reconstruction, and also of hamstring fixation to the medial femoral condyle for patella instability.

Electromagnetic Interference Tests

DTIC Science & Technology

1994-05-31

for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields (300 kHz - 100 GHz), American National Standards Institute...Respect to Human Exposure to Radio Frequency Electromagnetic Fields (300 kHz - 100 GHz), American National Standards Institute, C95.1-1982, 30 July 1980...II il~l I!I 11 lll i 13. ABSTkACT (Waxlrnun 200woruh) This TOP is a general guideline for electromagnetic interference testing of electronic

Fingerprint extraction from interference destruction terahertz spectrum.

PubMed

Xiong, Wei; Shen, Jingling

2010-10-11

In this paper, periodic peaks in a terahertz absorption spectrum are confirmed to be induced from interference effects. Theoretically, we explained the periodic peaks and calculated the locations of them. Accordingly, a technique was suggested, with which the interference peaks in a terahertz spectrum can be eliminated and therefore a real terahertz absorption spectrum can be obtained. Experimentally, a sample, Methamphetamine, was investigated and its terahertz fingerprint was successfully extracted from its interference destruction spectrum. This technique is useful in getting samples' terahertz fingerprint spectra, and furthermore provides a fast nondestructive testing method using a large size terahertz beam to identify materials.

Stress and binge drinking: A toxic combination for the teenage brain.

PubMed

Goldstein, Aaron; Déry, Nicolas; Pilgrim, Malcolm; Ioan, Miruna; Becker, Suzanna

2016-09-01

Young adult university students frequently binge on alcohol and have high stress levels. Based on findings in rodents, we predicted that heavy current alcohol use and elevated stress and depression scores would be associated with deficits on high interference memory tasks, while early onset, prolonged binge patterns would lead to broader cognitive deficits on tests of associative encoding and executive functions. We developed the Concentration Memory Task, a novel computerized version of the Concentration card game with a high degree of interference. We found that young adults with elevated stress, depression, and alcohol consumption scores were impaired in the Concentration Memory Task. We also analyzed data from a previous study, and found that higher alcohol consumption scores were associated with impaired performance on another high interference memory task, based on Kirwan and Stark's Mnemonic Similarity Test. On the other hand, adolescent onset of binge drinking predicted poorer performance on broader range of memory tests, including a more systematic test of spatial recognition memory, and an associative learning task. Our results are broadly consistent with findings in rodents that acute alcohol and stress exposure suppress neurogenesis in the adult hippocampus, which in turn impairs performance in high interference memory tasks, while adolescent onset binge drinking causes more extensive brain damage and cognitive deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Report of the EMI Testing of the Johnson Noise Thermometry System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Britton Jr., Charles L.; Roberts, Michael

This report summarizes the Electromagnetic Interference (EMI) testing of the Johnson Noise Thermometry System developed at ORNL. The EMI performance is very important for Johnson Noise Thermometry because it requires accurate measurement of a very small noise signal that is amplified 10,000 times. Any interference in the form on pickup from external signal sources from such as fluorescent lighting ballasts, motors, etc. can skew the measurement. Testing is therefore very important in determining the effects of these external noise sources. Results from testing in several environments with various sources of EMI are presented here.

An active interference projector for the electro-optical test facility

NASA Astrophysics Data System (ADS)

Crowe, D. G.; Nowak, T. M.

1980-09-01

A projection system is described which can simulate emissions from flares, muzzle-flashes, shellbursts, and other emissive agents which may degrade the performance of electro-optical systems in the 0.5-15 micron spectral range. The simulation capability obtained will allow the apparent radiance and temporal characteristics of muzzleflashes and shellbursts to be mimicked at simulated ranges as close as 23 m within the Electro-Optical Test Facility. This demonstrates that tests of electro-optical system performance in the presence of interferers can be performed under laboratory conditions with higher repeatability and lower cost than field tests.

Electric field controlled spin interference in a system with Rashba spin-orbit coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciftja, Orion, E-mail: ogciftja@pvamu.edu

There have been intense research efforts over the last years focused on understanding the Rashba spin-orbit coupling effect from the perspective of possible spintronics applications. An important component of this line of research is aimed at control and manipulation of electron’s spin degrees of freedom in semiconductor quantum dot devices. A promising way to achieve this goal is to make use of the tunable Rashba effect that relies on the spin-orbit interaction in a two-dimensional electron system embedded in a host semiconducting material that lacks inversion-symmetry. This way, the Rashba spin-orbit coupling effect may potentially lead to fabrication of amore » new generation of spintronic devices where control of spin, thus magnetic properties, is achieved via an electric field and not a magnetic field. In this work we investigate theoretically the electron’s spin interference and accumulation process in a Rashba spin-orbit coupled system consisting of a pair of two-dimensional semiconductor quantum dots connected to each other via two conducting semi-circular channels. The strength of the confinement energy on the quantum dots is tuned by gate potentials that allow “leakage” of electrons from one dot to another. While going through the conducting channels, the electrons are spin-orbit coupled to a microscopically generated electric field applied perpendicular to the two-dimensional system. We show that interference of spin wave functions of electrons travelling through the two channels gives rise to interference/conductance patterns that lead to the observation of the geometric Berry’s phase. Achieving a predictable and measurable observation of Berry’s phase allows one to control the spin dynamics of the electrons. It is demonstrated that this system allows use of a microscopically generated electric field to control Berry’s phase, thus, enables one to tune the spin-dependent interference pattern and spintronic properties with no need for injection of spin-polarized electrons.« less

Spatial interferences in the electron transport of heavy-fermion materials

NASA Astrophysics Data System (ADS)

Zhang, Shu-feng; Liu, Yu; Song, Hai-Feng; Yang, Yi-feng

2016-08-01

The scanning tunneling microscopy/spectroscopy and the point contact spectroscopy represent major progress in recent heavy-fermion research. Both have revealed important information on the composite nature of the emergent heavy-electron quasiparticles. However, a detailed and thorough microscopic understanding of the similarities and differences in the underlying physical processes of these techniques is still lacking. Here we study the electron transport in the normal state of the periodic Anderson lattice by using the Keldysh nonequilibrium Green's function technique. In addition to the well-known Fano interference between the conduction and f -electron channels, our results further reveal the effect of spatial interference between different spatial paths at the interface on the differential conductance and their interesting interplay with the band features such as the hybridization gap and the Van Hove singularity. We find that the spatial interference leads to a weighted average in the momentum space for the electron transport and could cause suppression of the electronic band features under certain circumstances. In particular, it reduces the capability of probing the f -electron spectral weight near the edges of the hybridization gap for large interface depending on the Fermi surface of the lead. Our results indicate an intrinsic inefficiency of the point contact spectroscopy in probing the f electrons.

Hemolysis indexes for biochemical tests and immunoassays on Roche analyzers: determination of allowable interference limits according to different calculation methods.

PubMed

Monneret, Denis; Mestari, Fouzi; Atlan, Gregory; Corlouer, Camille; Ramani, Zo; Jaffre, Jeremy; Dever, Sylvie; Fressart, Veronique; Alkouri, Rana; Lamari, Foudil; Devilliers, Catherine; Imbert-Bismut, Françoise; Bonnefont-Rousselot, Dominique

2015-04-01

To determine the hemolysis interference on biochemical tests and immunoassays performed on Roche Diagnostics analyzers, according to different maximum allowable limits. Heparinized plasma and serum pools, free of interferences, were overloaded by increasing amounts of a hemoglobin-titrated hemolysate. This interference was evaluated for 45 analytes using Modular(®) and Cobas(®) analyzers. For each parameter, the hemolysis index (HI) corresponding to the traditional ± 10% change of concentrations from baseline (± 10%Δ) was determined, as well as those corresponding to the analytical change limit (ACL), and to the reference change value (RCV). Then, the relative frequencies distribution (% RFD) of hemolyzed tests performed in a hospital laboratory over a 25-day period were established for each HI as allowable limit. Considering the ± 10%Δ, the analyte concentrations enhanced by hemolysis were: Lactate dehydrogenase (LDH), aspartate aminotransferase (AST), folate, potassium, creatine kinase, phosphorus, iron, alanine aminotransferase, lipase, magnesium and triglycerides, decreasingly. The analyte concentrations decreased by hemolysis were: Haptoglobin, high-sensitive troponin T and alkaline phosphatase. Over the 25-day period, the % RFD of tests impacted more than 10%Δ by hemolysis were < 7% for LDH; < 5% for AST, folates and iron; and < 1% for the other analytes. Considering the ACL, HI were lower, giving % RFD substantially increased for many analytes, whereas only four analytes remain sensitive to hemolysis when considering RCV. This study proposes new HI based on different allowable limits, and can therefore serve as a starting point for future harmonization of hemolysis interference evaluation needed in routine laboratory practice.

Phonon wave interference in graphene and boron nitride superlattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Xue-Kun; Zhou, Wu-Xing; Tang, Li-Ming

2016-07-11

The thermal transport properties of the graphene and boron nitride superlattice (CBNSL) are investigated via nonequilibrium molecular dynamics simulations. The simulation results show that a minimum lattice thermal conductivity can be achieved by changing the period length of the superlattice. Additionally, it is found that the period length at the minimum shifts to lower values at higher temperatures, and that the depth of the minimum increases with decreasing temperature. In particular, at 200 K, the thermal conductivities of CBNSLs with certain specific period lengths are nearly equal to the corresponding values at 300 K. A detailed analysis of the phonon spectra showsmore » that this anomalous thermal conductivity behavior is a result of strong phonon wave interference. These observations indicate a promising strategy for manipulation of thermal transport in superlattices.« less

A new high-resolution electromagnetic method for subsurface imaging

NASA Astrophysics Data System (ADS)

Feng, Wanjie

For most electromagnetic (EM) geophysical systems, the contamination of primary fields on secondary fields ultimately limits the capability of the controlled-source EM methods. Null coupling techniques were proposed to solve this problem. However, the small orientation errors in the null coupling systems greatly restrict the applications of these systems. Another problem encountered by most EM systems is the surface interference and geologic noise, which sometimes make the geophysical survey impossible to carry out. In order to solve these problems, the alternating target antenna coupling (ATAC) method was introduced, which greatly removed the influence of the primary field and reduced the surface interference. But this system has limitations on the maximum transmitter moment that can be used. The differential target antenna coupling (DTAC) method was proposed to allow much larger transmitter moments and at the same time maintain the advantages of the ATAC method. In this dissertation, first, the theoretical DTAC calculations were derived mathematically using Born and Wolf's complex magnetic vector. 1D layered and 2D blocked earth models were used to demonstrate that the DTAC method has no responses for 1D and 2D structures. Analytical studies of the plate model influenced by conductive and resistive backgrounds were presented to explain the physical phenomenology behind the DTAC method, which is the magnetic fields of the subsurface targets are required to be frequency dependent. Then, the advantages of the DTAC method, e.g., high-resolution, reducing the geologic noise and insensitive to surface interference, were analyzed using surface and subsurface numerical examples in the EMGIMA software. Next, the theoretical advantages, such as high resolution and insensitive to surface interference, were verified by designing and developing a low-power (moment of 50 Am 2) vertical-array DTAC system and testing it on controlled targets and scaled target coils. At last, a high-power (moment of about 6800 Am2) vertical-array DTAC system was designed, developed and tested on controlled buried targets and surface interference to illustrate that the DTAC system was insensitive to surface interference even with a high-power transmitter and having higher resolution by using the large-moment transmitter. From the theoretical and practical analysis and tests, several characteristics of the DTAC method were found: (1) The DTAC method can null out the effect of 1D layered and 2D structures, because magnetic fields are orientation independent which lead to no difference among the null vector directions. This characteristic allows for the measurements of smaller subsurface targets; (2) The DTAC method is insensitive to the orientation errors. It is a robust EM null coupling method. Even large orientation errors do not affect the measured target responses, when a reference frequency and one or more data frequencies are used; (3) The vertical-array DTAC method is effective in reducing the geologic noise and insensitive to the surface interference, e.g., fences, vehicles, power line and buildings; (4) The DTAC method is a high-resolution EM sounding method. It can distinguish the depth and orientation of subsurface targets; (5) The vertical-array DTAC method can be adapted to a variety of rapidly moving survey applications. The transmitter moment can be scaled for effective study of near-surface targets (civil engineering, water resource, and environmental restoration) as well as deep targets (mining and other natural-resource exploration).

Interference and negative priming effects in adolescents with attention deficit hyperactivity disorder.

PubMed

Pritchard, Verena E; Neumann, Ewald; Rucklidge, Julia J

2007-01-01

Three visual selective attention tasks were used to measure potential differences in susceptibility to interference and inhibitory cognitive control processes in 16 adolescents diagnosed with attention deficit hyperactivity disorder (ADHD) and 45 similar-aged controls. Susceptibility to interference was assessed using the Stroop color and word naming test. Efficiency of distractor inhibition was assessed in two conceptual negative priming tasks. The majority of studies in this area indicate that people with ADHD demonstrate higher levels of interference and lower negative priming effects in comparison with age-matched peers. However, we found that although the ADHD group was consistently slower to name target stimuli than the control group, there were no differences in interference or negative priming between the two groups.

Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

NASA Technical Reports Server (NTRS)

Sherman, Albert

1939-01-01

An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with the geometry of the combination. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for complete combination.

Transfer Failure and Proactive Interference in Short-Term Memory

ERIC Educational Resources Information Center

Ellis, John A.

1977-01-01

Two experiments tested the hypothesis that proactive interference over a series of Brown-Peterson trials results from a combination of the subject's failure to transfer information to a permanent memory state and failure to retrieve information from permanent memory. (Editor)

Contextual Interference Effects in Learning Three Badminton Serves.

ERIC Educational Resources Information Center

Goode, Sinah; Magill, Richard A.

1986-01-01

This study was made to validate results obtained in laboratory research. Thirty female students learned three badminton serves in either a low, mixed, or high interference practice schedule and were given a retention and transfer test. Results are discussed. (Author/MT)

Effects of conflicting auditory stimuli on color-word interference and arousal.

DOT National Transportation Integrated Search

1971-03-01

Although air traffic controllers are often required to perform in the presence of distracting stimuli, no adequate measures of distraction susceptibility exist. In the study, 50 male subjects were tested to determine whether the interference effect p...

Pre-lexical disorders in repetition conduction aphasia.

PubMed

Sidiropoulos, Kyriakos; de Bleser, Ria; Ackermann, Hermann; Preilowski, Bruno

2008-12-01

At the level of clinical speech/language evaluation, the repetition type of conduction aphasia is characterized by repetition difficulties concomitant with reduced short-term memory capacities, in the presence of fluent spontaneous speech as well as unimpaired naming and reading abilities. It is still unsettled which dysfunctions of the pre-lexical processing stage of spoken word recognition contribute to this syndrome and whether there is any relevant top-down impact of the mental lexicon upon the phonetic/phonological level of speech perception. In order to further specify the underlying pathomechanisms, a comprehensive battery of psycholinguistic tests was applied to a patient suffering from repetition conduction aphasia. The obtained results point at a pre-lexical disorder in this subject. To further specify the assumed pre-lexical dysfunction, computer simulations of single-word processing, based upon an interactive activation model (IAM), were conducted. An attenuation of the features-to-phonemes inhibition value was found to simulate the observed profile of psycholinguistic deficits. Conceivably, these pre-lexical disorders interfere with the task-dependent adjustment of the temporal windows of signal analysis, giving rise to compromised sequencing of auditory-verbal information.

Multipath interference test method using synthesized chirped signal from directly modulated DFB-LD with digital-signal-processing technique.

PubMed

Aida, Kazuo; Sugie, Toshihiko

2011-12-12

We propose a method of testing transmission fiber lines and distributed amplifiers. Multipath interference (MPI) is detected as a beat spectrum between a multipath signal and a direct signal using a synthesized chirped test signal with lightwave frequencies of f(1) and f(2) periodically emitted from a distributed feedback laser diode (DFB-LD). This chirped test pulse is generated using a directly modulated DFB-LD with a drive signal calculated using a digital signal processing technique (DSP). A receiver consisting of a photodiode and an electrical spectrum analyzer (ESA) detects a baseband power spectrum peak appearing at the frequency of the test signal frequency deviation (f(1)-f(2)) as a beat spectrum of self-heterodyne detection. Multipath interference is converted from the spectrum peak power. This method improved the minimum detectable MPI to as low as -78 dB. We discuss the detailed design and performance of the proposed test method, including a DFB-LD drive signal calculation algorithm with DSP for synthesis of the chirped test signal and experiments on single-mode fibers with discrete reflections. © 2011 Optical Society of America

Internal Friction And Instabilities Of Rotors

NASA Technical Reports Server (NTRS)

Walton, J.; Artiles, A.; Lund, J.; Dill, J.; Zorzi, E.

1992-01-01

Report describes study of effects of internal friction on dynamics of rotors prompted by concern over instabilities in rotors of turbomachines. Theoretical and experimental studies described. Theoretical involved development of nonlinear mathematical models of internal friction in three joints found in turbomachinery - axial splines, Curvic(TM) splines, and interference fits between smooth cylindrical surfaces. Experimental included traction tests to determine the coefficients of friction of rotor alloys at various temperatures, bending-mode-vibration tests of shafts equipped with various joints and rotordynamic tests of shafts with axial-spline and interference-fit joints.

Flight test of a passive millimeter-wave imaging system

NASA Astrophysics Data System (ADS)

Martin, Christopher A.; Manning, Will; Kolinko, Vladimir G.; Hall, Max

2005-05-01

A real-time passive millimeter-wave imaging system with a wide-field of view and 3K temperature sensitivity is described. The system was flown on a UH-1H helicopter in a flight test conducted by the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD). We collected approximately eight hours of data over the course of the two-week flight test. Flight data was collected in horizontal and vertical polarizations at look down angles from 0 to 40 degrees. Speeds varied from 0 to 90 knots and altitudes varied from 0' to 1000'. Targets imaged include roads, freeways, railroads, houses, industrial buildings, power plants, people, streams, rivers, bridges, cars, trucks, trains, boats, planes, runways, treelines, shorelines, and the horizon. The imaging system withstood vibration and temperature variations, but experienced some RF interference. The flight test demonstrated the system's capabilities as an airborne navigation and surveillance aid. It also performed in a personnel recovery scenario.

1700 deg C optical temperature sensor

NASA Technical Reports Server (NTRS)

Mossey, P. W.; Shaffernocker, W. M.; Mulukutla, A. R.

1986-01-01

A new gas temperature sensor was developed that shows promise of sufficient ruggedness to be useful as a gas turbine temperature sensor. The sensor is in the form of a single-crystal aluminum oxide ceramic, ground to a cone shape and given an emissive coating. A lens and an optical fiber conduct the thermally emitted light to a remote and near-infrared photodetector assembly. Being optically coupled and passive, the sensor is highly immune to all types of electrical interference. Candidate sensors were analyzed for optical sensor performance, heat transfer characteristics, stress from gas loading. This led to the selection of the conical shape as the most promising for the gas turbine environment. One uncoated and two coated sensing elements were prepared for testing. Testing was conducted to an indicated 1750 C in a propane-air flame. Comparison with the referee optical pyrometer shows an accuracy of + or - 25 C at 1700 C for this initial development. One hundred cycles from room temperature to 1700 C left the sapphire cone intact, but some loss of the platinum, 6% rhodium coating was observed. Several areas for improving the overall performance and durability are identified.

Effect of a High-Intensity, Intermittent-Exercise Protocol on Neurocognitive Function in Healthy Adults: Implications for Return-to-Play Management After Sport-Related Concussion.

PubMed

Whyte, Enda F; Gibbons, Nicola; Kerr, Grainne; Moran, Kieran A

2015-12-03

Determination of return to play (RTP) after sport-related concussion (SRC) is critical given the potential consequences of premature RTP. Current RTP guidelines may not identify persistent exercise-induced neurocognitive deficits in asymptomatic athletes after SRC. Therefore, postexercise neurocognitive testing has been recommended to further inform RTP determination. To implement this recommendation, the effect of exercise on neurocognitive function in healthy athletes should be understood. To examine the acute effects of a high-intensity intermittent-exercise protocol (HIIP) on neurocognitive function assessed by the Symbol Digits Modality Test (SDMT) and Stroop Interference Test. Cohort study. University laboratory. 40 healthy male athletes (age 21.25 ± 1.29 y, education 16.95 ± 1.37 y). Each participant completed the SDMT and Stroop Interference Test at baseline and after random allocation to a condition (HIIP vs control). A mixed between-within-subjects ANOVA assessed time- (pre- vs postcondition) -by-condition interaction effects. SDMT and Stroop Interference Test scores. There was a significant time-by-condition interaction effect (P < .001, η2 = .364) for the Stroop Interference Test scores, indicating that the HIIP group scored significantly lower (56.05 ± 9.34) postcondition than the control group (66.39 ± 19.6). There was no significant time-by-condition effect (P = .997, η2 < .001) for the SDMT, indicating that there was no difference between SDMT scores for the HIIP and control groups (59.95 ± 10.7 vs 58.56 ± 14.02). In healthy athletes, the HIIP results in a reduction in neurocognitive function as assessed by the Stroop Interference Test, with no effect on function as assessed by the SDMT. Testing should also be considered after high-intensity exercise in determining RTP decisions for athletes after SRC in conjunction with the existing recommended RTP protocol. These results may provide an initial reference point for future research investigating the effects of an HIIP on the neurocognitive function of athletes recovering from SRC.

Revisiting the co-existence of Attention-Deficit/Hyperactivity Disorder and Chronic Tic Disorder in childhood-The case of colour discrimination, sustained attention and interference control.

PubMed

Uebel-von Sandersleben, Henrik; Albrecht, Björn; Rothenberger, Aribert; Fillmer-Heise, Anke; Roessner, Veit; Sergeant, Joseph; Tannock, Rosemary; Banaschewski, Tobias

2017-01-01

Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter two reflect important aspects for psychoeducation and behavioural treatment approaches. Colour discrimination using the Farnsworth-Munsell 100-hue Test, sustained attention during the Frankfurt Attention Inventory (FAIR), and interference liability during Colour- and Counting-Stroop-Tests were assessed to further clarify the cognitive profile of the co-existence of ADHD and CTD. Altogether 69 children were classified into four groups: ADHD (N = 14), CTD (N = 20), ADHD+CTD (N = 20) and healthy Controls (N = 15) and compared in cognitive functioning in a 2×2-factorial statistical model. Difficulties with colour discrimination were associated with both ADHD and CTD factors following an additive model, but in ADHD these difficulties tended to be more pronounced on the blue-yellow axis. Attention problems were characteristic for ADHD but not CTD. Interference load was significant in both Colour- and Counting-Stroop-Tests and unrelated to colour discrimination. Compared to Controls, interference load in the Colour-Stroop was higher in pure ADHD and in pure CTD, but not in ADHD+CTD, following a sub-additive model. In contrast, interference load in the Counting-Stroop did not reveal ADHD or CTD effects. The co-existence of ADHD and CTD is characterized by additive as well as sub-additive performance impairments, suggesting that their co-existence may show simple additive characteristics of both disorders or a more complex interaction, depending on demand. The equivocal findings on interference control may indicate limited validity of the Stroop-Paradigm for clinical assessments.

Interference studies with two hospital-grade and two home-grade glucose meters.

PubMed

Lyon, Martha E; Baskin, Leland B; Braakman, Sandy; Presti, Steven; Dubois, Jeffrey; Shirey, Terry

2009-10-01

Interference studies of four glucose meters (Nova Biomedical [Waltham, MA] StatStrip [hospital grade], Roche Diagnostics [Indianapolis, IN] Accu-Chek Aviva [home grade], Abbott Diabetes Care [Alameda, CA] Precision FreeStyle Freedom [home grade], and LifeScan [Milpitas, CA] SureStep Flexx [hospital grade]) were evaluated and compared to the clinical laboratory plasma hexokinase reference method (Roche Hitachi 912 chemistry analyzer). These meters were chosen to reflect the continuum of care from hospital to home grade meters commonly seen in North America. Within-run precision was determined using a freshly prepared whole blood sample spiked with concentrated glucose to give three glucose concentrations. Day-to-day precision was evaluated using aqueous control materials supplied by each vendor. Common interferences, including hematocrit, maltose, and ascorbate, were tested alone and in combination with one another on each of the four glucose testing devices at three blood glucose concentrations. Within-run precision for all glucose meters was <5% except for the FreeStyle (up to 7.6%). Between-day precision was <6% for all glucose meters. Ascorbate caused differences (percentage change from a sample without added interfering substances) of >5% with pyrroloquinolinequinone (PQQ)-glucose dehydrogenase-based technologies (Aviva and Freestyle) and the glucose oxidase-based Flexx meter. Maltose strongly affected the PQQ-glucose dehydrogenase-based meter systems. When combinations of interferences (ascorbate, maltose, and hematocrit mixtures) were tested, the extent of the interference was up to 193% (Aviva), 179% (FreeStyle), 25.1% (Flexx), and 5.9% (StatStrip). The interference was most pronounced at low glucose (3.9-4.4 mmol/L). All evaluated glucose meter systems demonstrated varying degrees of interference by hematocrit, ascorbate, and maltose mixtures. PQQ-glucose dehydrogenase-based technologies showed greater susceptibility than glucose oxidase-based systems. However, the modified glucose oxidase-based amperometric method (Nova StatStrip) was less affected in comparison with the glucose oxidase-based photometric method (LifeScan SureStep Flexx).

Revisiting the co-existence of Attention-Deficit/Hyperactivity Disorder and Chronic Tic Disorder in childhood—The case of colour discrimination, sustained attention and interference control

PubMed Central

Rothenberger, Aribert; Fillmer-Heise, Anke; Roessner, Veit; Sergeant, Joseph; Tannock, Rosemary; Banaschewski, Tobias

2017-01-01

Objective Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter two reflect important aspects for psychoeducation and behavioural treatment approaches. Methods Colour discrimination using the Farnsworth-Munsell 100-hue Test, sustained attention during the Frankfurt Attention Inventory (FAIR), and interference liability during Colour- and Counting-Stroop-Tests were assessed to further clarify the cognitive profile of the co-existence of ADHD and CTD. Altogether 69 children were classified into four groups: ADHD (N = 14), CTD (N = 20), ADHD+CTD (N = 20) and healthy Controls (N = 15) and compared in cognitive functioning in a 2×2-factorial statistical model. Results Difficulties with colour discrimination were associated with both ADHD and CTD factors following an additive model, but in ADHD these difficulties tended to be more pronounced on the blue-yellow axis. Attention problems were characteristic for ADHD but not CTD. Interference load was significant in both Colour- and Counting-Stroop-Tests and unrelated to colour discrimination. Compared to Controls, interference load in the Colour-Stroop was higher in pure ADHD and in pure CTD, but not in ADHD+CTD, following a sub-additive model. In contrast, interference load in the Counting-Stroop did not reveal ADHD or CTD effects. Conclusion The co-existence of ADHD and CTD is characterized by additive as well as sub-additive performance impairments, suggesting that their co-existence may show simple additive characteristics of both disorders or a more complex interaction, depending on demand. The equivocal findings on interference control may indicate limited validity of the Stroop-Paradigm for clinical assessments. PMID:28594866

The interplay of parental support, parental pressure and test anxiety--Gender differences in adolescents.

PubMed

Ringeisen, Tobias; Raufelder, Diana

2015-12-01

This study examined gender-specific relationships between adolescents' perceptions of school-related support/pressure from their parents and test anxiety. A sample of German students (N = 845; Mage = 15.32; SD = .49) completed questionnaires that measured their perceived parental support/pressure (for mother and father separately) as well as the four main components of test anxiety (worry, interference, lack of confidence, and emotionality). Gender-specific relations were identified using multigroup structural equation modeling: For girls, perceived maternal pressure was positively associated with emotionality and interference; for boys, perceived father pressure and father support were positively associated with interference and worry, respectively. For both genders, perceived mother pressure and support were related to lack of confidence. Our findings suggest that adolescents' perceptions of maternal attitudes are associated with students' self-confidence irrespective of the child's gender, whereas the remaining facets of test anxiety follow same-sex trajectories between perceived parental attitudes and adolescents' test anxiety. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Testing protects against proactive interference in face-name learning.

PubMed

Weinstein, Yana; McDermott, Kathleen B; Szpunar, Karl K

2011-06-01

Learning face-name pairings at a social function becomes increasingly more difficult the more individuals one meets. This phenomenon is attributable to proactive interference--the negative influence of prior learning on subsequent learning. Recent evidence suggests that taking a memory test can alleviate proactive interference in verbal list learning paradigms. We apply this technique to face-name pair learning. Participants studied four lists of 12 face-name pairings and either attempted to name the 12 faces just studied after every list or did not. Recall attempts after every list improved learning of the fourth list by over 100%. Moreover, no reduction in learning of face-name pairings occurred from list 1 to list 4 for participants who attempted to name studied faces between lists. These results suggest that testing oneself on the names of a group of new acquaintances before moving on to the next group is an effective mnemonic technique for social functions.

A qualitative study of interference with communicative participation across communication disorders in adults.

PubMed

Baylor, Carolyn; Burns, Michael; Eadie, Tanya; Britton, Deanna; Yorkston, Kathryn

2011-11-01

To explore the similarities and differences in self-reported restrictions in communicative participation across different communication disorders in community-dwelling adults. Interviews were conducted with 44 adults representing 7 different medical conditions: spasmodic dysphonia, multiple sclerosis, stroke, stuttering, Parkinson's disease, amyotrophic lateral sclerosis, and laryngectomy. This article represents a secondary analysis of qualitative data collected in cognitive interviews during development of the Communicative Participation Item Bank. The data were analyzed to identify themes in participants' experiences related to communicative participation. Participants described many situations in which they experienced interference in communicative participation. Two themes emerged from the data. The first theme was Interference is both "functional" and "emotional," in which participants defined interference as limitations in accomplishing tasks and emotional consequences. The second theme was "It depends"-sources of interference, in which participants described many variables that contribute to interference in participation. Participants had limited control of some variables such as symptoms and environmental contexts, but personal decisions and priorities also influenced participation. Despite different impairments and activity limitations, participants described similar communicative participation restrictions. These similarities may have theoretical and clinical implications in terms of how we assess, treat, and study the participation restrictions associated with communication disorders.

Aerofoil testing in a self-streamlining flexible walled wind tunnel. Ph.D. Thesis - Jul. 1987

NASA Technical Reports Server (NTRS)

Lewis, Mark Charles

1988-01-01

Two-dimensional self-streamlining flexible walled test sections eliminate, as far as experimentally possible, the top and bottom wall interference effects in transonic airfoil testing. The test section sidewalls are rigid, while the impervious top and bottom walls are flexible and contoured to streamline shapes by a system of jacks, without reference to the airfoil model. The concept of wall contouring to eliminate or minimize test section boundary interference in 2-D testing was first demonstrated by NPL in England during the early 40's. The transonic streamlining strategy proposed, developed and used by NPL has been compared with several modern strategies. The NPL strategy has proved to be surprisingly good at providing a wall interference-free test environment, giving model performance indistinguishable from that obtained using the modern strategies over a wide range of test conditions. In all previous investigations the achievement of wall streamlining in flexible walled test sections has been limited to test sections up to those resulting in the model's shock just extending to a streamlined wall. This work however, has also successfully demonstrated the feasibility of 2-D wall streamlining at test conditions where both model shocks have reached and penetrated through their respective flexible walls. Appropriate streamlining procedures have been established and are uncomplicated, enabling flexible walled test sections to cope easily with these high transonic flows.

Failure to Recover from Proactive Semantic Interference and Abnormal Limbic Connectivity in Asymptomatic, Middle-Aged Offspring of Patients with Late-Onset Alzheimer's Disease.

PubMed

Sánchez, Stella M; Abulafia, Carolina; Duarte-Abritta, Barbara; de Guevara, M Soledad Ladrón; Castro, Mariana N; Drucaroff, Lucas; Sevlever, Gustavo; Nemeroff, Charles B; Vigo, Daniel E; Loewenstein, David A; Villarreal, Mirta F; Guinjoan, Salvador M

2017-01-01

We have obtained previous evidence of limbic dysfunction in middle-aged, asymptomatic offspring of late-onset Alzheimer's disease (LOAD) patients, and failure to recover from proactive semantic interference has been shown to be a sensitive cognitive test in other groups at risk for LOAD. To assess the effects of specific proactive semantic interference deficits as they relate to functional magnetic resonance imaging (fMRI) neocortical and limbic functional connectivity in middle aged offspring of individuals with LOAD (O-LOAD) and age-equivalent controls. We examined 21 O-LOAD and 20 controls without family history of neurodegenerative disorders (CS) on traditional measures of cognitive functioning and the LASSI-L, a novel semantic interference test uniquely sensitive to the failure to recover from proactive interference (frPSI). Cognitive tests then were correlated to fMRI connectivity of seeds located in entorhinal cortex and anterodorsal thalamic nuclei among O-LOAD and CS participants. Relative to CS, O-LOAD participants evidenced lower connectivity between entorhinal cortex and orbitofrontal, anterior cingulate, and anterior temporal cortex. In the offspring of LOAD patients, LASSI-L measures of frPSI were inversely associated with connectivity between anterodorsal thalamus and contralateral posterior cingulate. Intrusions on the task related to frPSI were inversely correlated with a widespread connectivity network involving hippocampal, insular, posterior cingulate, and dorsolateral prefrontal cortices, along with precunei and anterior thalamus in this group. Different patterns of connectivity associated with frPSI were observed among controls. The present results suggest that both semantic interference deficits and connectivity abnormalities might reflect limbic circuit dysfunction as a very early clinical signature of LOAD pathology, as previously demonstrated for other limbic phenotypes, such as sleep and circadian alterations.

Analysis of electromagnetic interference from power system processing and transmission components for Space Station Freedom

NASA Technical Reports Server (NTRS)

Barber, Peter W.; Demerdash, Nabeel A. O.; Hurysz, B.; Luo, Z.; Denny, Hugh W.; Millard, David P.; Herkert, R.; Wang, R.

1992-01-01

The goal of this research project was to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom. The approach consists of four steps: (1) developing analytical tools (models and computer programs); (2) conducting parameterization (what if?) studies; (3) predicting the global space station EMI environment; and (4) providing a basis for modification of EMI standards.

Interference control in working memory: comparing groups of children with atypical development.

PubMed

Palladino, Paola; Ferrari, Marcella

2013-01-01

The study aimed to test whether working memory deficits in children at risk of Learning Disabilities (LD) and/or attention deficit/hyperactivity disorder (ADHD) can be attributed to deficits in interference control, thereby implicating prefrontal systems. Two groups of children known for showing poor working memory (i.e., children with poor comprehension and children with ADHD) were compared to a group of children with specific reading decoding problems (i.e., having severe problems in phonological rather than working memory) and to a control group. All children were tested with a verbal working memory task. Interference control of irrelevant items was examined by a lexical decision task presented immediately after the final recall in about half the trials, selected at random. The interference control measure was therefore directly related to working memory performance. Results confirmed deficient working memory performance in poor comprehenders and children at risk of ADHD + LD. More interestingly, this working memory deficit was associated with greater activation of irrelevant information than in the control group. Poor decoders showed more efficient interference control, in contrast to poor comprehenders and ADHD + LD children. These results indicated that interfering items were still highly accessible to working memory in children who fail the working memory task. In turn, these findings strengthen and clarify the role of interference control, one of the most critical prefrontal functions, in working memory.

Sleep and memory consolidation: motor performance and proactive interference effects in sequence learning.

PubMed

Borragán, Guillermo; Urbain, Charline; Schmitz, Rémy; Mary, Alison; Peigneux, Philippe

2015-04-01

That post-training sleep supports the consolidation of sequential motor skills remains debated. Performance improvement and sensitivity to proactive interference are both putative measures of long-term memory consolidation. We tested sleep-dependent memory consolidation for visuo-motor sequence learning using a proactive interference paradigm. Thirty-three young adults were trained on sequence A on Day 1, then had Regular Sleep (RS) or were Sleep Deprived (SD) on the night after learning. After two recovery nights, they were tested on the same sequence A, then had to learn a novel, potentially competing sequence B. We hypothesized that proactive interference effects on sequence B due to the prior learning of sequence A would be higher in the RS condition, considering that proactive interference is an indirect marker of the robustness of sequence A, which should be better consolidated over post-training sleep. Results highlighted sleep-dependent improvement for sequence A, with faster RTs overnight for RS participants only. Moreover, the beneficial impact of sleep was specific to the consolidation of motor but not sequential skills. Proactive interference effects on learning a new material at Day 4 were similar between RS and SD participants. These results suggest that post-training sleep contributes to optimizing motor but not sequential components of performance in visuo-motor sequence learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Mug shot exposure prior to lineup identification: interference, transference, and commitment effects.

PubMed

Dysart, J E; Lindsay, R C; Hammond, R; Dupuis, P

2001-12-01

The effects of viewing mug shots on subsequent identification performance are as yet unclear. Two experiments used a live staged-crime paradigm to determine if interpolated eyewitness exposure to mug shots caused interference, unconscious transference, or commitment effects influencing subsequent lineup accuracy. Experiment 1 (N = 104) tested interference effects. Similar correct decision rates were obtained for the mug shot and no mug shot groups from both perpetrator-present and absent lineups. Experiment 2 (N = 132) tested for commitment and transference effects. Results showed that the commitment group made significantly more incorrect identifications than either the control or the transference group, which had similar false-identification rates. Commitment effects present a serious threat to identification accuracy from lineups following mug shot searches.

Simulate different environments TDLAS On the analysis of the test signal strength

NASA Astrophysics Data System (ADS)

Li, Xin; Zhou, Tao; Jia, Xiaodong

2014-12-01

TDLAS system is the use of the wavelength tuning characteristics of the laser diode, for detecting the absorption spectrum of the gas absorption line. Detecting the gas space, temperature, pressure and flow rate and concentration. The use of laboratory techniques TDLAS gas detection, experimental simulation engine combustion water vapor and smoke. using an optical lens system receives the signal acquisition and signal interference test analysis. Analog water vapor and smoke in two different environments in the sample pool interference. In both experiments environmental interference gas absorption in the optical signal acquisition, signal amplitude variation analysis, and records related to the signal data. In order to study site conditions in the engine combustion process for signal acquisition provides an ideal experimental data .

Application of the correlation constrained multivariate curve resolution alternating least-squares method for analyte quantitation in the presence of unexpected interferences using first-order instrumental data.

PubMed

Goicoechea, Héctor C; Olivieri, Alejandro C; Tauler, Romà

2010-03-01

Correlation constrained multivariate curve resolution-alternating least-squares is shown to be a feasible method for processing first-order instrumental data and achieve analyte quantitation in the presence of unexpected interferences. Both for simulated and experimental data sets, the proposed method could correctly retrieve the analyte and interference spectral profiles and perform accurate estimations of analyte concentrations in test samples. Since no information concerning the interferences was present in calibration samples, the proposed multivariate calibration approach including the correlation constraint facilitates the achievement of the so-called second-order advantage for the analyte of interest, which is known to be present for more complex higher-order richer instrumental data. The proposed method is tested using a simulated data set and two experimental data systems, one for the determination of ascorbic acid in powder juices using UV-visible absorption spectral data, and another for the determination of tetracycline in serum samples using fluorescence emission spectroscopy.

Interference effect between neutron direct and resonance capture reactions for neutron-rich nuclei

NASA Astrophysics Data System (ADS)

Minato, Futoshi; Fukui, Tokuro

2017-11-01

Interference effect of neutron capture cross section between the compound and direct processes is investigated. The compound process is calculated by resonance parameters and the direct process by the potential model. The interference effect is tested for neutron-rich 82Ge and 134Sn nuclei relevant to r-process and light nucleus 13C which is neutron poison in the s-process and produces long-lived radioactive nucleus 14C (T1/2 = 5700 y). The interference effects in those nuclei are significant around resonances, and low energy region if s-wave neutron direct capture is possible. Maxwellian averaged cross sections at kT = 30 and 300 keV are also calculated, and the interference effect changes the Maxwellian averaged capture cross section largely depending on resonance position.

Heterophilic interference in specimens yielding false-reactive results on the Abbott 4th generation ARCHITECT HIV Ag/Ab Combo assay.

PubMed

Lavoie, S; Caswell, D; Gill, M J; Kadkhoda, K; Charlton, C L; Levett, P N; Hatchette, T; Garceau, R; Maregmen, J; Mazzulli, T; Needle, R; Kadivar, K; Kim, J

2018-07-01

False-reactivity in HIV-negative specimens has been detected in HIV fourth-generation antigen/antibody or 'combo' assays which are able to detect both anti-HIV-1/HIV-2 antibodies and HIV-1 antigen. We sought to characterize these specimens and determine the effect of heterophilic interference. Specimens previously testing as false-reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay and re-tested on a different (Siemens ADVIA Centaur HIV Ag/Ab) assay. A subset of these specimens were also pre-treated with heterophilic blocking agents and re-tested on the Abbott assay. Here we report that 95% (252/264) of clinical specimens that were repeatedly reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay (S/Co range, 0.94-678) were negative when re-tested on a different fourth generation HIV combo assay (Siemens ADVIA Centaur HIV Ag/Ab). All 264 samples were subsequently confirmed to be HIV negative. On a small subset (57) of specimens with available volume, pre-treatment with two different reagents (HBT; Heterophilic Blocking Tube, NABT; Non-Specific Blocking Tube) designed to block heterophilic antibody interference either eliminated (HBT) or reduced (NABT) the false reactivity when re-tested on the ARCHITECT HIV Ag/Ab combo assay. Our results suggest that the Abbott ARCHITECT HIV Ag/Ab combo assay can be prone to heterophilic antibody interference. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

The Role of Test Context in Latent Inhibition of Conditioned Inhibition: Part of a Search for General Principles of Associative Interference

PubMed Central

Miguez, Gonzalo; Soares, Julia S.; Miller, Ralph R.

2015-01-01

Two lick-suppression experiments with rats assessed interference with behavior indicative of conditioned inhibition by a latent inhibition treatment as a function of test context. We asked what effect the test context has, given identical latent inhibition treatment in Phase 1 and identical conditioned inhibition training in Phase 2. In Experiment 1, an AAA vs. AAB context-shift design determined that latent inhibition treatment in Phase 1 attenuated behavior indicative of conditioned inhibition training administered in Phase 2 regardless of the test context, which could reflect a failure to either acquire or express conditioned inhibition. In Experiment 2, an ABA vs. ABB design found that test performance in Contexts A and B reflected the treatments that had been administered in those contexts (i.e., conditioned inhibition was observed in Context B but not A), which could reflect either context specificity of latent inhibition or context specificity of conditioned inhibition. In either case, latent inhibition of conditioned inhibition training in at least some situations was seen to reflect an expression deficit rather than an acquisition deficit. These data, in conjunction with prior reports, suggest that latent inhibition is relatively specific to the context in which it was administered, whereas conditioned inhibition is specific to its training context only when it is the second learned relationship concerning the target cue. These experiments are part of a larger effort to delineate control by the test context of two-phase associative interference as a function of the nature of target training and the nature of interference training. PMID:25875792

The role of test context in latent inhibition of conditioned inhibition: Part of a search for general principles of associative interference.

PubMed

Miguez, Gonzalo; Soares, Julia S; Miller, Ralph R

2015-09-01

In two lick suppression experiments with rats, we assessed interference with behavior indicative of conditioned inhibition by a latent inhibition treatment as a function of test context. We asked what effect the test context has, given identical latent inhibition treatments in Phase 1 and identical conditioned inhibition trainings in Phase 2. In Experiment 1, an AAA versus AAB context-shift design determined that the latent inhibition treatment in Phase 1 attenuated behavior indicative of the conditioned inhibition training administered in Phase 2, regardless of the test context, which could reflect a failure to either acquire or express conditioned inhibition. In Experiment 2, an ABA versus ABB design showed that test performance in Contexts A and B reflected the treatments that had been administered in those contexts (i.e., conditioned inhibition was observed in Context B but not A), which could reflect either the context specificity of either latent inhibition or conditioned inhibition. In either case, latent inhibition of conditioned inhibition training in at least some situations was seen to reflect an expression deficit rather than an acquisition deficit. These data, in conjunction with prior reports, suggest that latent inhibition is relatively specific to the context in which it was administered, whereas conditioned inhibition is specific to its training context only when it is the second-learned relationship concerning the target cue. These experiments are part of a larger effort to delineate control by the test context of two-phase associative interference, as a function of the nature of target training and the nature of interference training.

Performance of a new test strip for freestyle blood glucose monitoring systems.

PubMed

Lock, John Paul; Brazg, Ronald; Bernstein, Robert M; Taylor, Elizabeth; Patel, Mona; Ward, Jeanne; Alva, Shridhara; Chen, Ting; Welsh, Zoë; Amor, Walter; Bhogal, Claire; Ng, Ronald

2011-01-01

a new strip, designed to enhance the ease of use and minimize interference of non-glucose sugars, has been developed to replace the current FreeStyle (Abbott Diabetes Care, Alameda, CA) blood glucose test strip. We evaluated the performance of this new strip. laboratory evaluation included precision, linearity, dynamic range, effects of operating temperature, humidity, altitude, hematocrit, interferents, and blood reapplication. System accuracy, lay user performance, and ease of use for finger capillary blood testing and accuracy for venous blood testing were evaluated at clinics. Lay users also compared the speed and ease of use between the new strip and the current FreeStyle strip. for glucose concentrations <75 mg/dL, 73%, 100%, and 100% of the individual capillary blood glucose results obtained by lay users fell within ± 5, 10, and 15 mg/dL, respectively, of the reference. For glucose concentrations ≥75 mg/dL, 68%, 95%, 99%, and 99% of the lay user results fell within  ±  5%, 10%, 15%, and 20%, respectively, of the reference. Comparable accuracy was obtained in the venous blood study. Lay users found the new test strip easy to use and faster and easier to use than the current FreeStyle strip. The new strip maintained accuracy under various challenging conditions, including high concentrations of various interferents, sample reapplication up to 60 s, and extremes in hematocrit, altitude, and operating temperature and humidity. our results demonstrated excellent accuracy of the new FreeStyle test strip and validated the improvements in minimizing interference and enhancing ease of use.

Suppression of Quasiparticle Scattering Signals in Bilayer Graphene Due to Layer Polarization and Destructive Interference

NASA Astrophysics Data System (ADS)

Jolie, Wouter; Lux, Jonathan; Pörtner, Mathias; Dombrowski, Daniela; Herbig, Charlotte; Knispel, Timo; Simon, Sabina; Michely, Thomas; Rosch, Achim; Busse, Carsten

2018-03-01

We study chemically gated bilayer graphene using scanning tunneling microscopy and spectroscopy complemented by tight-binding calculations. Gating is achieved by intercalating Cs between bilayer graphene and Ir(111), thereby shifting the conduction band minima below the chemical potential. Scattering between electronic states (both intraband and interband) is detected via quasiparticle interference. However, not all expected processes are visible in our experiment. We uncover two general effects causing this suppression: first, intercalation leads to an asymmetrical distribution of the states within the two layers, which significantly reduces the scanning tunneling spectroscopy signal of standing waves mainly present in the lower layer; second, forward scattering processes, connecting points on the constant energy contours with parallel velocities, do not produce pronounced standing waves due to destructive interference. We present a theory to describe the interference signal for a general n -band material.

Interband interference effects at the edge of a multiband chiral p -wave superconductor

NASA Astrophysics Data System (ADS)

Zhang, Jia-Long; Huang, Wen; Sigrist, Manfred; Yao, Dao-Xin

2017-12-01

Chiral superconductors support chiral edge modes and potentially spontaneous edge currents at their boundaries. Motivated by the putative multiband chiral p -wave superconductor Sr2RuO4 , we study the influence of the interference between different bands at the edges, which may appear in the presence of moderate edge disorder or in edge tunneling measurements. We show that interband interference can strongly modify the measurable quantities at the edges when the order parameter exhibits phase difference between the bands. This is illustrated by investigating the edge dispersion and the edge current distribution in the presence of interband mixing, as well as the conductance at a tunneling junction. The results are discussed in connection with the putative chiral p -wave superconductor Sr2RuO4 . In passing, we also discuss similar interference effects in multiband models with other pairing symmetries.

Suppression of Quasiparticle Scattering Signals in Bilayer Graphene Due to Layer Polarization and Destructive Interference.

PubMed

Jolie, Wouter; Lux, Jonathan; Pörtner, Mathias; Dombrowski, Daniela; Herbig, Charlotte; Knispel, Timo; Simon, Sabina; Michely, Thomas; Rosch, Achim; Busse, Carsten

2018-03-09

We study chemically gated bilayer graphene using scanning tunneling microscopy and spectroscopy complemented by tight-binding calculations. Gating is achieved by intercalating Cs between bilayer graphene and Ir(111), thereby shifting the conduction band minima below the chemical potential. Scattering between electronic states (both intraband and interband) is detected via quasiparticle interference. However, not all expected processes are visible in our experiment. We uncover two general effects causing this suppression: first, intercalation leads to an asymmetrical distribution of the states within the two layers, which significantly reduces the scanning tunneling spectroscopy signal of standing waves mainly present in the lower layer; second, forward scattering processes, connecting points on the constant energy contours with parallel velocities, do not produce pronounced standing waves due to destructive interference. We present a theory to describe the interference signal for a general n-band material.

Static internal performance of a single expansion ramp nozzle with multiaxis thrust vectoring capability

NASA Technical Reports Server (NTRS)

Capone, Francis J.; Schirmer, Alberto W.

1993-01-01

An investigation was conducted at static conditions in order to determine the internal performance characteristics of a multiaxis thrust vectoring single expansion ramp nozzle. Yaw vectoring was achieved by deflecting yaw flaps in the nozzle sidewall into the nozzle exhaust flow. In order to eliminate any physical interference between the variable angle yaw flap deflected into the exhaust flow and the nozzle upper ramp and lower flap which were deflected for pitch vectoring, the downstream corners of both the nozzle ramp and lower flap were cut off to allow for up to 30 deg of yaw vectoring. The effects of nozzle upper ramp and lower flap cutout, yaw flap hinge line location and hinge inclination angle, sidewall containment, geometric pitch vector angle, and geometric yaw vector angle were studied. This investigation was conducted in the static-test facility of the Langley 16-Foot Transonic Tunnel at nozzle pressure ratios up to 8.0.

Photoconductive circuit element reflectometer

DOEpatents

Rauscher, Christen

1990-01-01

A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a variable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line.

Photoconductive circuit element reflectometer

DOEpatents

Rauscher, C.

1987-12-07

A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a determinable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line. 4 figs.

Maintenance rehearsal: the key to the role attention plays in storage and forgetting.

PubMed

McFarlane, Kimberley A; Humphreys, Michael S

2012-07-01

Research with the maintenance-rehearsal paradigm, in which word pairs are rehearsed as distractor material during a series of digit recall trials, has previously indicated that low frequency and new word pairs capture attention to a greater degree than high frequency and old word pairs. This impacts delayed recognition of the pairs and interferes with immediate digit recall. The effect on immediate digit recall may provide the missing converging evidence for the role of attention in memory. In the current study, 3 experiments were conducted to further investigate the role of attention capture and novelty in storage and forgetting. In addition to the previously established effects, the novelty of switching rehearsal between 2 pairs was found to impair both digit recall and memory for the first pair. The attentional effects we obtained were dependent upon participant expectation, and forgetting appears to be due to interference with consolidation rather than decay or traditional associative interference. Finally, the attentional effects we observed in associative recognition were primarily reflected in a lowering of the false alarm rate with increases in the strength of the parent pairs. Although dual-process models can accommodate this finding on the assumption that recollection is invoked at test alongside familiarity, we showed that the level of recall in this paradigm is so small that recollection can be ruled out. Accordingly, our results are challenging for the existing models of associative recognition to accommodate. 2012 APA, all rights reserved

User's manual for a 0.3-m TCT wall interference assessment/correction procedure: 8- by 24-inch airfoil test section

NASA Technical Reports Server (NTRS)

Gumbert, C. R.

1985-01-01

A transonic Wall-Interference Assessment/Correction (WIAC) procedure has been developed and verified for the 8- by 24-inch airfoil test section of the Langley 0.3-m Transonic Cryogenic Tunnel. This report is a user's manual for the correction procedure. It includes a listing of the computer procedure file as well as input for and results from a step-by-step sample case.

Evaluation of available analytical techniques for monitoring the quality of space station potable water

NASA Technical Reports Server (NTRS)

Geer, Richard D.

1989-01-01

To assure the quality of potable water (PW) on the Space Station (SS) a number of chemical and physical tests must be conducted routinely. After reviewing the requirements for potable water, both direct and indirect analytical methods are evaluated that could make the required tests and improvements compatible with the Space Station operation. A variety of suggestions are made to improve the analytical techniques for SS operation. The most important recommendations are: (1) the silver/silver chloride electrode (SB) method of removing I sub 2/I (-) biocide from the water, since it may interfere with analytical procedures for PW and also its end uses; (2) the orbital reactor (OR) method of carrying out chemistry and electrochemistry in microgravity by using a disk shaped reactor on an orbital table to impart artificial G force to the contents, allowing solution mixing and separation of gases and liquids; and (3) a simple ultra low volume highly sensitive electrochemical/conductivity detector for use with a capillary zone electrophoresis apparatus. It is also recommended, since several different conductivity and resistance measurements are made during the analysis of PW, that the bipolar pulse measuring circuit be used in all these applications for maximum compatibility and redundancy of equipment.

Interference and Noise in and Adjacent to the Loran-C Spectrum at Airports

DOT National Transportation Integrated Search

1980-05-01

Electrical noise and interference in the LORAN-C frequency band was measured at two rural airports in Vermont and a major airport in Boston, Mass. The purpose of the test program was to determine the potential interfering sources that could affect th...

Imaging snake orbits at graphene n -p junctions

NASA Astrophysics Data System (ADS)

Kolasiński, K.; Mreńca-Kolasińska, A.; Szafran, B.

2017-01-01

We consider conductance mapping of the snake orbits confined along the n -p junction defined in graphene by the electrostatic doping in the quantum Hall regime. We explain the periodicity of conductance oscillations at the magnetic field and the Fermi energy scales by the properties of the n -p junction as a conducting channel. We evaluate the conductance maps for a floating gate scanning the surface of the device. In the quantum Hall conditions the currents flow near the edges of the sample and along the n -p junction. The conductance mapping resolves only the n -p junction and not the edges. The conductance oscillations along the junction are found in the maps with periodicity related to the cyclotron orbits of the scattering current. Stronger probe potentials provide support to localized resonances at one of the sides of the junction with current loops that interfere with the n -p junction currents. The interference results in a series of narrow lines parallel to the junction with positions that strongly depend on the magnetic field through the Aharonov-Bohm effect. The consequences of a limited transparency of finite-width n -p junctions are also discussed.

An investigation of conducted and radiated emissions from a hollow-cathode plasma contactor

NASA Astrophysics Data System (ADS)

Buchholtz, Brett W.; Wilbur, Paul J.

1993-07-01

An investigation conducted on the electrical interference induced by the operation of a hollow-cathode plasma contractor in a ground-based facility is described. The types of electrical interference, or noise, which are important to Space Station Freedom designers are classified as either conducted or radiated emissions. The procedures required to perform conducted and radiated emission measurements on a plasma contactor are examined. The experimental data obtained are typically examined in the frequency domain (i.e. amplitudes of the noise fluctuations versus frequency). Results presented indicate the conducted emissions, which are the current fluctuations from the contactor into the space station wiring, are affected by operating parameters such as expellant flow rate and discharge current. The radiated emissions, which are the electromagnetic waves induced and emitted by the contactor, appear to be influenced by the contactor emission current. Other experimental results suggest possible sources which are responsible for the observed noise. For example, the influence of the plasma environment downstream from the contactor on noise emission levels is described. In addition, a brief discussion is given on the correlation between conducted and radiated emissions and the mechanisms through which both are influenced by the plasma downstream of the contactor.

An investigation of conducted and radiated emissions from a hollow-cathode plasma contactor

NASA Technical Reports Server (NTRS)

Buchholtz, Brett W.; Wilbur, Paul J.

1993-01-01

An investigation conducted on the electrical interference induced by the operation of a hollow-cathode plasma contractor in a ground-based facility is described. The types of electrical interference, or noise, which are important to Space Station Freedom designers are classified as either conducted or radiated emissions. The procedures required to perform conducted and radiated emission measurements on a plasma contactor are examined. The experimental data obtained are typically examined in the frequency domain (i.e. amplitudes of the noise fluctuations versus frequency). Results presented indicate the conducted emissions, which are the current fluctuations from the contactor into the space station wiring, are affected by operating parameters such as expellant flow rate and discharge current. The radiated emissions, which are the electromagnetic waves induced and emitted by the contactor, appear to be influenced by the contactor emission current. Other experimental results suggest possible sources which are responsible for the observed noise. For example, the influence of the plasma environment downstream from the contactor on noise emission levels is described. In addition, a brief discussion is given on the correlation between conducted and radiated emissions and the mechanisms through which both are influenced by the plasma downstream of the contactor.

Influence of press-fit parameters on the primary stability of uncemented femoral resurfacing implants.

PubMed

Gebert, A; Peters, J; Bishop, N E; Westphal, F; Morlock, M M

2009-01-01

Primary stability is essential to the success of uncemented prostheses. It is strongly influenced by implantation technique, implant design and bone quality. The goal of this study was to investigate the effect of press-fit parameters on the primary stability of uncemented femoral head resurfacing prostheses. An in vitro study with human specimens and prototype implants (nominal radial interference 170 and 420 microm) was used to investigate the effect of interference on primary stability. A finite element model was used to assess the influence of interference, friction between implant and bone, and bone quality. Primary stability was represented by the torque capacity of the implant. The model predicted increasing stability with actual interference, bone quality and friction coefficient; plastic deformation of the bone began at interferences of less than 100 microm. Experimentally, however, stability was not related to interference. This may be due to abrasion or the collapse of trabecular bone structures at higher interferences, which could not be captured by the model. High nominal interferences as tested experimentally appear unlikely to result in improved stability clinically. An implantation force of about 2,500 N was estimated to be sufficient to achieve a torque capacity of about 30 N m with a small interference (70 microm).

The cause of divorce among men and women referred to marriage and legal office in Qazvin, Iran.

PubMed

Barikani, Ameneh; Ebrahim, Sarichlow Mohamad; Navid, Mohammadi

2012-08-27

Marital separation and divorce can be the most unpleasant event in the adult's life, and families will be hurt by divorce event. The prevalence of divorce has been increased in last decades. Therefore, this study was conducted to identify the divorce cause among the divorce seeking men and women in Qazvin, Iran. This cross-sectional study was conducted among 572 (400 women and 172 men) subjects who requested for divorce and were referred to divorce and marriage office of Qazvin province during 3 month in 2009. Data were collected by self - administered questionnaire, interviewing subjects and using Likert scale. Data were analyzed by Chi- Square test and Mann-Whitney (SPSS version 16). The participants of the study included 400 women (26.5 ± 7.4 years) and 172 men. In view points of women the primary wrong mate selection was main cause of divorce (59.8%), but the men believed that the families and relatives interference was the main reason for separation (43.7%). Among the respondents, mean score of "dependency to their families" and "unmet emotional needs" were 3.44 ± 1.6 and 3.86 ± 1.4 respectively. In addition mean score of infertility among men and women were 1.37 ± 1.0 and 1.29 ± 0.9 respectively. Wrong mate selection, unmet emotional needs, families' interference, and "dependency to families" are more important factors than traditional factors which are sexual or physical factors.

Biomechanical Evaluation of All-Polyethylene Pegged Bony Ingrowth Glenoid Fixation Techniques on Implant Micromotion.

PubMed

Wiater, Brett P; Moravek, James E; Kurdziel, Michael D; Baker, Kevin C; Wiater, J Michael

2016-01-01

Newer glenoid components that allow for hybrid cement fixation via traditional cementation of peripheral pegs and bony ingrowth into an interference-fit central peg introduce the possibility of long-term biological fixation. However, little biomechanical work has been done on the initial stability of these components and the various fixation options. We conducted a study in which all-polyethylene glenoid components with a centrally fluted peg were implanted in polyurethane blocks with interference-fit, hybrid cement, and fully cemented fixation (5 per fixation group). Biomechanical evaluation of glenoid loosening, according to ASTM Standard F-2028-12, subjected the glenoids to 50,000 cycles of rim loading, and glenoid component motion was recorded with 2 differential variable reluctance transducers fixed to each glenoid prosthesis. Fully cemented fixation exhibited significantly less mean distraction in comparison with interference-fit fixation (P < .001) and hybrid cement fixation (P < .001). Hybrid cement fixation exhibited significantly less distraction (P < .001), more compression (P < .001), and no significant difference in glenoid translation (P = .793) in comparison with interference-fit fixation. Fully cemented fixation exhibited the most resistance to glenoid motion in comparison with hybrid cement fixation and interference-fit fixation. However, hybrid cement fixation and interference-fit fixation exhibited equivocal motion. Given these results, cementation of peripheral pegs may confer no additional initial stability over that provided by uncemented interference-fit fixation.

Practicing Field Hockey Skills Along the Contextual Interference Continuum: A Comparison of Five Practice Schedules

PubMed Central

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J. Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners. PMID:24149204

Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

PubMed

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

Axial-Force Reduction by Interference Between Jet and Neighboring Afterbody

NASA Technical Reports Server (NTRS)

Pitts, William C.; Wiggins, Lyle E.

1960-01-01

Experimental results are presented for an exploratory investigation of the effectiveness of interference between jet and afterbody in reducing the axial force on an afterbody with a neighboring jet. In addition to the interference axial force., measurements are presented of the interference normal force and the center of pressure of the interference normal force. The free-stream Mach number was 2.94, the jet-exit Mach number was 2.71, and the Reynolds number was 0.25 x 10, based on body diameter. The variables investigated include static-pressure ratio of the jet (up to 9), nacelle position relative to afterbody, angle of attack (-5 deg to 10 deg), and afterbody shape. Two families of afterbody shapes were tested. One family consisted of tangent-ogive bodies of revolution with varying length and base areas. The other family was formed by taking a planar slice off a circular cylinder with varying angle between the plane and cylinder. The trends with these variables are shown for conditions near maximum jet-afterbody interference. The interference axial forces are large and favorable. For several configurations the total afterbody axial force is reduced to zero by the interference.

Heterophilic antibody interference affecting multiple hormone assays: Is it due to rheumatoid factor?

PubMed

Mongolu, Shiva; Armston, Annie E; Mozley, Erin; Nasruddin, Azraai

2016-01-01

Assay interference with heterophilic antibodies has been well described in literature. Rheumatoid factor is known to cause similar interference leading to falsely elevated hormone levels when measured by immunometric methods like enzyme-linked immunosorbent assay (ELISA) or multiplex immunoasays (MIA). We report a case of a 60-year-old male patient with a history of rheumatoid arthritis referred to our endocrine clinic for investigation of hypogonadism and was found to have high serum levels of LH, FSH, SHBG, Prolactin, HCG and TSH. We suspected assay interference and further tests were performed. We used Heteroblock tubes and PEG precipitation to eliminate the interference and the hormone levels post treatment were in the normal range. We believe the interference was caused by high serum levels of rheumatoid factor. Although he was treated with thyroxine for 3 years, we believe he may have been treated inappropriately as his Free T4 level was always normal despite high TSH due to assay interference. Our case illustrates the phenomenon of heterophilic antibody interference likely due to high levels of rheumatoid factor. It is essential for clinicians and endocrinologists in particular to be aware of this possibility when making treatment decisions in these groups of patients.

The effects of particles and dissolved materials on in situ algal pigment fluorescence sensors

NASA Astrophysics Data System (ADS)

Saraceno, J.; Bergamaschi, B. A.; Downing, B. D.

2013-12-01

Field deployable sensors that measure algal pigment fluorescence (APF), such as chlorophyll-a (excitation/emission ca. 470/685 nm), and phycocyanin (ca. 590/685 nm), have been used to estimate algal biomass and study food-web dynamics in coastal and oceanic waters for many years. There is also widespread use of these sensors in real time river-observing networks. However, freshwater systems often possess elevated levels of suspended solids and dissolved organic material that can interfere with optical measurements. Data collected under conditions that result in interferences may not be comparable across time and between sites unless the data are appropriately corrected. Using standard reference materials and a surrogate for algal fluorescence (Rhodamine WT), lab experiments were conducted on several commercially available sensors to quantify sensitivity to interferences over a range of naturally occurring surface water conditions (DOC : 0-30 mg/L and turbidity: 0- 1000 FNU ). Chlorophyll-a sensors exhibited a slight but significant positive bias (<1%) at DOC concentrations < 2 mg/L, and a negative, non-linear bias at DOC concentrations >2 mg/L, with signal quenching reaching a maximum of 15% at 30 mg/L DOC. All phycocyanin sensors displayed a positive non-linear bias with DOC concentration, reaching a maximum of 40% difference at 30 mg/L DOC. Both chlorophyll-a and phycocyanin sensors showed a positive linear relationship with suspended solids concentration (as indicated by turbidity).The effect of suspended solids on APF output can be explained by the detection of scattered excitation light (leaking through emission filters). Similar qualitative effects were observed for the sensors tested, though the magnitude of the effect varied among sensor type. This indicates that differences in sensor designs such as geometry, wavelength and signal post processing techniques is related to its sensitivity to interferences. Although sensors exhibited significant cross sensitivity to interferences, our results indicate that simple corrections can largely remove sensor bias. To remove bias due to optical interferences and generate high quality, repeatable APF data, knowledge of the optical properties of the matrix and/or coincident measures of the concentration of suspended solids and dissolved organics (through surrogates such as turbidity and colored dissolved organic matter (cDOM) fluorescence, respectively), are typically needed.

Effects of groundwater withdrawals from the Hurricane Fault zone on discharge of saline water from Pah Tempe Springs, Washington County, Utah

USGS Publications Warehouse

Gardner, Philip M.

2018-04-10

Pah Tempe Springs, located in Washington County, Utah, contribute about 95,000 tons of dissolved solids annually along a 1,500-foot gaining reach of the Virgin River. The river gains more than 10 cubic feet per second along the reach as thermal, saline springwater discharges from dozens of orifices located along the riverbed and above the river on both banks. The spring complex discharges from fractured Permian Toroweap Limestone where the river crosses the north-south trending Hurricane Fault. The Bureau of Reclamation Colorado River Basin Salinity Control Program is evaluating the feasibility of capturing and desalinizing the discharge of Pah Tempe Springs to improve downstream water quality in the Virgin River. The most viable plan, identified by the Bureau of Reclamation in early studies, is to capture spring discharge by pumping thermal groundwater from within the Hurricane Fault footwall damage zone and to treat this water prior to returning it to the river.Three multiple-day interference tests were conducted between November 2013 and November 2014, wherein thermal groundwater was pumped from fractured carbonate rock in the fault damage zone at rates of up to 7 cubic feet per second. Pumping periods for these tests lasted approximately 66, 74, and 67 hours, respectively, and the tests occurred with controlled streamflows of approximately 2.0, 3.5, and 24.5 cubic feet per second, respectively, in the Virgin River upstream from the springs reach. Specific conductance, water temperature, and discharge were monitored continuously in the river (upstream and downstream of the springs reach) at selected individual springs, and in the pumping discharge during each of the tests. Water levels were monitored in three observation wells screened in the thermal system. Periodic stream and groundwater samples were analyzed for dissolved-solids concentration and the stable isotopes of oxygen and hydrogen. Additional discrete measurements of field parameters (specific conductance, water temperature, pH, and discharge) were made at up to 26 sites along the springs reach. These data demonstrate the interaction between the saline, thermal groundwater system and the Virgin River, and provide estimates of reductions in dissolved-solids loads to the river.The interference tests show that pumping thermal groundwater from the shallow carbonate aquifer adjacent to the springs is effective at capturing high dissolved-solids loads discharging from Pah Tempe Springs before they enter the Virgin River. Discharge measurements made in the Virgin River downstream of the springs reach show that streamflow is reduced by approximately the amount pumped, indicating that complete capture of thermal discharge is possible. During the February 2014 test, the dissolved-solids load removed by pumping (190 tons per day) was approximately equal to the dissolved-solids load reduction observed in the river below the springs reach, indicating near 100-percent efficient capture of spring-sourced dissolved solids. However, an observed decrease in temperature and specific conductance of the pumping discharge during the high-flow test in November 2014 showed that capture of the cool, fresh river water can occur and is more likely at a higher stage in the Virgin River.

Controlling destructive quantum interference in tunneling junctions comprising self-assembled monolayers via bond topology and functional groups† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c8sc00165k

PubMed Central

Zhang, Yanxi; Ye, Gang; Soni, Saurabh; Qiu, Xinkai; Krijger, Theodorus L.; Jonkman, Harry T.; Carlotti, Marco; Sauter, Eric; Zharnikov, Michael

2018-01-01

Quantum interference effects (QI) are of interest in nano-scale devices based on molecular tunneling junctions because they can affect conductance exponentially through minor structural changes. However, their utilization requires the prediction and deterministic control over the position and magnitude of QI features, which remains a significant challenge. In this context, we designed and synthesized three benzodithiophenes based molecular wires; one linearly-conjugated, one cross-conjugated and one cross-conjugated quinone. Using eutectic Ga–In (EGaIn) and CP-AFM, we compared them to a well-known anthraquinone in molecular junctions comprising self-assembled monolayers (SAMs). By combining density functional theory and transition voltage spectroscopy, we show that the presence of an interference feature and its position can be controlled independently by manipulating bond topology and electronegativity. This is the first study to separate these two parameters experimentally, demonstrating that the conductance of a tunneling junction depends on the position and depth of a QI feature, both of which can be controlled synthetically. PMID:29896382

Facilitation and interference in naming: A consequence of the same learning process?

PubMed

Hughes, Julie W; Schnur, Tatiana T

2017-08-01

Our success with naming depends on what we have named previously, a phenomenon thought to reflect learning processes. Repeatedly producing the same name facilitates language production (i.e., repetition priming), whereas producing semantically related names hinders subsequent performance (i.e., semantic interference). Semantic interference is found whether naming categorically related items once (continuous naming) or multiple times (blocked cyclic naming). A computational model suggests that the same learning mechanism responsible for facilitation in repetition creates semantic interference in categorical naming (Oppenheim, Dell, & Schwartz, 2010). Accordingly, we tested the predictions that variability in semantic interference is correlated across categorical naming tasks and is caused by learning, as measured by two repetition priming tasks (picture-picture repetition priming, Exp. 1; definition-picture repetition priming, Exp. 2, e.g., Wheeldon & Monsell, 1992). In Experiment 1 (77 subjects) semantic interference and repetition priming effects were robust, but the results revealed no relationship between semantic interference effects across contexts. Critically, learning (picture-picture repetition priming) did not predict semantic interference effects in either task. We replicated these results in Experiment 2 (81 subjects), finding no relationship between semantic interference effects across tasks or between semantic interference effects and learning (definition-picture repetition priming). We conclude that the changes underlying facilitatory and interfering effects inherent to lexical access are the result of distinct learning processes where multiple mechanisms contribute to semantic interference in naming. Copyright © 2017 Elsevier B.V. All rights reserved.

Contrastive Study between Pronunciation Chinese L1 and English L2 from the Perspective of Interference Based on Observations in Genuine Teaching Contexts

ERIC Educational Resources Information Center

Li, Feng

2016-01-01

Much research has been conducted on factors that impact on second language (L2) speech production in light of the age of L2 acquisition, the length of residence in the L2 environment, motivation, the amount of first language (L1) usage, etc. Very little of this research has taken the perspective of interference between L1 and L2, especially with…

Modeling and experimental verification of laser self-mixing interference phenomenon with the structure of two-external-cavity feedback

NASA Astrophysics Data System (ADS)

Chen, Peng; Liu, Yuwei; Gao, Bingkun; Jiang, Chunlei

2018-03-01

A semiconductor laser employed with two-external-cavity feedback structure for laser self-mixing interference (SMI) phenomenon is investigated and analyzed. The SMI model with two directions based on F-P cavity is deduced, and numerical simulation and experimental verification were conducted. Experimental results show that the SMI with the structure of two-external-cavity feedback under weak light feedback is similar to the sum of two SMIs.