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1

Barriers and traps: great apes' performance in two functionally equivalent tasks.  

PubMed

Tool-using tasks that require subjects to overcome the obstacles to get a reward have been a major component of research investigating causal knowledge in primates. Much of the debate in this research has focused on whether subjects simply use certain stimulus features or instead use more functionally relevant information regarding the effect that certain features may have on a moving reward. Here, we presented two obstacle tasks, a trap platform and a barrier platform, to 22 great apes. Although perceptually similar, these two tasks contain two perceptually different but functionally equivalent obstacles: a trap and a barrier. In a pre-exposure phase, subjects either experienced an obstacle task or a task without any obstacle. In the transfer phase, all subjects were presented with an obstacle task, either the trap platform or the barrier platform. Our results show that those subjects who received an obstacle task prior to the second task performed better than those who first received a non-obstacle task. The type of obstacle task that subjects received first did not have any effect on their performance in the transfer phase. We suggest that apes possess some knowledge about the effects that obstacles have on slow-moving unsupported objects. PMID:22544302

Martin-Ordas, Gema; Jaeck, Franka; Jaek, Franka; Call, Josep

2012-09-01

2

Reconfiguring gene traps for new tasks using iTRAC  

PubMed Central

We recently developed integrase-mediated trap conversion (iTRAC) as a means of exploiting gene traps to create new genetic tools, such as new markers for imaging, drivers for gene expression and landing sites for gene and chromosome engineering. The principle of iTRAC is simple: primary gene traps are generated with transposon vectors carrying ?C31 integrase docking sites, which are subsequently utilized to integrate different constructs into trapped loci. Thus, iTRAC allows us to reconfigure selected traps for new purposes. Two features make iTRAC an attractive approach for Drosophila research. First, its versatility permits the exploitation of gene traps in an open-ended way, for applications that were not envisaged during the primary trapping screen. Second, iTRAC is readily transferable to new species and provides a means for developing complex genetic tools in Drosophilids that lack the facility of Drosophila melanogaster genetics.

Kontarakis, Zacharias; Konstantinides, Nikolaos; Pavlopoulos, Anastasios

2011-01-01

3

How great apes perform on a modified trap-tube task.  

PubMed

To date, neither primates nor birds have shown clear evidence of causal knowledge when attempting to solve the trap tube task. One factor that may have contributed to mask the knowledge that subjects may have about the task is that subjects were only allowed to push the reward away from them, which is a particularly difficult action for primates in certain problem solving situations. We presented five orangutans (Pongo pygmaeus), two chimpanzees (Pan troglodytes), two bonobos (Pan paniscus), and one gorilla (Gorilla gorilla) with a modified trap tube that allowed subjects to push or rake the reward with the tool. In two additional follow-up tests, we inverted the tube 180 degrees rendering the trap nonfunctional and also presented subjects with the original task in which they were required to push the reward out of the tube. Results showed that all but one of the subjects preferred to rake the reward. Two orangutans and one chimpanzee (all of whom preferred to rake the reward), consistently avoided the trap only when it was functional but failed the original task. These findings suggest that some great apes may have some causal knowledge about the trap-tube task. Their success, however, depended on whether they were allowed to choose certain tool-using actions. PMID:16612632

Mulcahy, Nicholas J; Call, Josep

2006-07-01

4

Classification of motor imagery tasks for brain-computer interface applications by means of two equivalent dipoles analysis  

Microsoft Academic Search

We have developed a novel approach using source analysis for classifying motor imagery tasks. Two-equivalent-dipoles analysis was proposed to aid classification of motor imagery tasks for brain-computer interface (BCI) applications. By solving the electroencephalography (EEG) inverse problem of single trial data, it is found that the source analysis approach can aid classification of motor imagination of left- or right-hand movement

Baharan Kamousi; Zhongming Liu; Bin He

2005-01-01

5

New head equivalent phantom for task and image performance evaluation representative for neurovascular procedures occurring in the Circle of Willis  

PubMed Central

Phantom equivalents of different human anatomical parts are routinely used for imaging system evaluation or dose calculations. The various recommendations on the generic phantom structure given by organizations such as the AAPM, are not always accurate when evaluating a very specific task. When we compared the AAPM head phantom containing 3 mm of aluminum to actual neuro-endovascular image guided interventions (neuro-EIGI) occurring in the Circle of Willis, we found that the system automatic exposure rate control (AERC) significantly underestimated the x-ray parameter selection. To build a more accurate phantom for neuro-EIGI, we reevaluated the amount of aluminum which must be included in the phantom. Human skulls were imaged at different angles, using various angiographic exposures, at kV’s relevant to neuro-angiography. An aluminum step wedge was also imaged under identical conditions, and a correlation between the gray values of the imaged skulls and those of the aluminum step thicknesses was established. The average equivalent aluminum thickness for the skull samples for frontal projections in the Circle of Willis region was found to be about 13 mm. The results showed no significant changes in the average equivalent aluminum thickness with kV or mAs variation. When a uniform phantom using 13 mm aluminum and 15 cm acrylic was compared with an anthropomorphic head phantom the x-ray parameters selected by the AERC system were practically identical. These new findings indicate that for this specific task, the amount of aluminum included in the head equivalent must be increased substantially from 3 mm to a value of 13 mm.

Ionita, Ciprian N.; Loughran, Brendan; Jain, Amit; Swetadri Vasan, S. N.; Bednarek, Daniel R.; Levy, Elad; Siddiqui, Adnan H.; Snyder, Kenneth V.; Hopkins, L. N.; Rudin, Stephen

2012-01-01

6

The Social Attribution Task-Multiple Choice (SAT-MC): A Psychometric and Equivalence Study of an Alternate Form  

PubMed Central

The Social Attribution Task-Multiple Choice (SAT-MC) uses a 64-second video of geometric shapes set in motion to portray themes of social relatedness and intentions. Considered a test of “Theory of Mind,” the SAT-MC assesses implicit social attribution formation while reducing verbal and basic cognitive demands required of other common measures. We present a comparability analysis of the SAT-MC and the new SAT-MC-II, an alternate form created for repeat testing, in a university sample (n = 92). Score distributions and patterns of association with external validation measures were nearly identical between the two forms, with convergent and discriminant validity supported by association with affect recognition ability and lack of association with basic visual reasoning. Internal consistency of the SAT-MC-II was superior (alpha = .81) to the SAT-MC (alpha = .56). Results support the use of SAT-MC and new SAT-MC-II as equivalent test forms. Demonstrating relatively higher association to social cognitive than basic cognitive abilities, the SAT-MC may provide enhanced sensitivity as an outcome measure of social cognitive intervention trials.

Johannesen, Jason K.; Lurie, Jessica B.; Fiszdon, Joanna M.; Bell, Morris D.

2013-01-01

7

Depth dependence of absorbed dose, dose equivalent and linear energy transfer spectra of galactic and trapped particles in polyethylene and comparison with calculations of models  

NASA Technical Reports Server (NTRS)

A matched set of five tissue-equivalent proportional counters (TEPCs), embedded at the centers of 0 (bare), 3, 5, 8 and 12-inch-diameter polyethylene spheres, were flown on the Shuttle flight STS-81 (inclination 51.65 degrees, altitude approximately 400 km). The data obtained were separated into contributions from trapped protons and galactic cosmic radiation (GCR). From the measured linear energy transfer (LET) spectra, the absorbed dose and dose-equivalent rates were calculated. The results were compared to calculations made with the radiation transport model HZETRN/NUCFRG2, using the GCR free-space spectra, orbit-averaged geomagnetic transmission function and Shuttle shielding distributions. The comparison shows that the model fits the dose rates to a root mean square (rms) error of 5%, and dose-equivalent rates to an rms error of 10%. Fairly good agreement between the LET spectra was found; however, differences are seen at both low and high LET. These differences can be understood as due to the combined effects of chord-length variation and detector response function. These results rule out a number of radiation transport/nuclear fragmentation models. Similar comparisons of trapped-proton dose rates were made between calculations made with the proton transport model BRYNTRN using the AP-8 MIN trapped-proton model and Shuttle shielding distributions. The predictions of absorbed dose and dose-equivalent rates are fairly good. However, the prediction of the LET spectra below approximately 30 keV/microm shows the need to improve the AP-8 model. These results have strong implications for shielding requirements for an interplanetary manned mission.

Badhwar, G. D.; Cucinotta, F. A.; Wilson, J. W. (Principal Investigator)

1998-01-01

8

Moderate Intense Physical Activity Depends on Selected Metabolic Equivalent of Task (MET) Cut-Off and Type of Data Analysis  

PubMed Central

Background Accelerometry data are frequently analyzed without considering whether moderate-to-vigorous physical activities (MVPA) were performed in bouts of >10 minutes as defined in most physical activity guidelines. We aimed i) to quantify MVPA by using different commonly-applied physical activity guidelines, ii) to investigate the effect of bouts versus non-bouts analysis, and iii) to propose and validate a MVPA non-bouts cut-point to classify (in-) active subjects. Methods Healthy subjects (n=110;62±6yrs) and patients with Chronic Obstructive Pulmonary Disease (COPD) (n=113;62±5yrs) wore an activity monitor for 7 days. Three Metabolic Equivalent of Task (MET) cut-offs and one individual target (50% VO2 reserve) were used to define MVPA. First, all minutes of MVPA were summed up (NON-BOUTS). Secondly, only minutes performed in bouts of >10 minutes continuous activity were counted (BOUTS). Receiver operating characteristic (ROC) curve analyses were used to propose and (cross-) validate new MVPA non-bout cut-points based on the criterion of 30 minutes MVPA per day (BOUTS). Likelihood ratios (sensitivity/[1-specificity]) were used to express the association between the proposed MVPA non-bout target and the MVPA bout target of 30 min*day-1. Results MVPA was variable across physical activity guidelines with lowest values for age-specific cut-offs. Selecting a METs cut-point corresponding to 50% VO2 reserve revealed no differences in MVPA between groups. MVPA’s analyzed in BOUTS in healthy subjects were 2 to 4 fold lower than NON-BOUTS analyses and this was even 3 to 12 fold lower in COPD. The MVPA non-bouts cut-point of 80 min*day-1 using a 3 METs MVPA threshold delivered positive likelihood ratios of 5.1[1.5-19.6] (healthy subjects) and 2.3[1.6-3.3] (COPD). Conclusion MVPA varies upon the selected physical activity guideline/targets and bouts versus non-bouts analysis. Accelerometry measured MVPA non-bouts target of 80 min*day-1, using a 3 METs MVPA threshold, is associated to the commonly-used MVPA bout target of 30 min*day-1.

Langer, Daniel; Hornikx, Miek; Demeyer, Heleen; Burtin, Chris; Decramer, Marc; Gosselink, Rik; Janssens, Wim; Troosters, Thierry

2013-01-01

9

Learning from others' mistakes? limits on understanding a trap-tube task by young chimpanzees (Pan troglodytes) and children (Homo sapiens).  

PubMed

A trap-tube task was used to determine whether chimpanzees (Pan troglodytes) and children (Homo sapiens) who observed a model's errors and successes could master the task in fewer trials than those who saw only successes. Two- to 7-year-old chimpanzees and 3- to 4-year-old children did not benefit from observing errors and found the task difficult. Two of the 6 chimpanzees developed a successful anticipatory strategy but showed no evidence of representing the core causal relations involved in trapping. Three- to 4-year-old children showed a similar limitation and tended to copy the actions of the demonstrator, irrespective of their causal relevance. Five- to 6-year-old children were able to master the task but did not appear to be influenced by social learning or benefit from observing errors. PMID:17324071

Horner, Victoria; Whiten, Andrew

2007-02-01

10

Tryptophan-14 is the preferred site of DBNBS spin trapping in the self-peroxidation reaction of sperm whale metmyoglobin with a single equivalent of hydrogen peroxide.  

PubMed

The 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS)-metmyoglobin adduct formed following the horse metmyoglobin-H(2)O(2) reaction has been assigned to both a tyrosyl and a tryptophanyl residue radical. At low H(2)O(2), hyperfine coupling to a (13)C atom in sperm whale metmyoglobin labeled at the tryptophan residues with (13)C allowed the unequivocal assignment of the primary adduct to a tryptophanyl radical. Trapping at Trp-14 of sperm whale myoglobin was indicated by greatly decreased electron paramagnetic resonance (EPR) spectral intensity of the DBNBS adducts of the Trp-14-Phe recombinant proteins. Complex EPR spectra with partially resolved hyperfine splittings from several atoms were obtained by pronase treatment of the DBNBS/*W14F metmyoglobin adducts. The EPR spectra of authentic DBNBS/*Tyr adducts were incubation time-dependent; the late time spectra resembled the spectra of pronase-treated DBNBS/*W14F sperm whale myoglobin adducts, suggesting formation of an unstable tyrosyl radical adduct in the latter proteins. When the H(2)O(2):metmyoglobin ratio was increased to 5:1, the EPR spectrum after pronase treatment supported trapping of a tyrosyl radical, although similar decreases in tryptophan content were detected at H(2)O(2):metmyoglobin ratios of 1:1 and 5:1. PMID:12755595

Gunther, Michael R; Tschirret-Guth, Richard A; Lardinois, Olivier M; Ortiz de Montellano, Paul R

2003-05-01

11

7.EE Equivalent Expressions?  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: If we multiply $\\frac{x}{2} + \\frac34$ by 4, we get $2x+3$. Is $2x+3$ an equivalent expression to $\\frac{x}{2} + \\frac34$?...

12

Storm- and tide-dominated shorelines in Cretaceous Moosebar-lower Gates interval-outcrop equivalents of Deep basin gas trap in western Canada  

SciTech Connect

The Moosebar and Gates Formations crop out in the deformed Foothills belt south of Fort St. John, British Columbia. They permit examination of the depositional environments of sandstones and conglomerates that are gas-bearing in the equivalent Wilrich-Falher interval of the Deep basin of Alberta and British Columbia. The Moosebar-Gates interval consists of several upward-coarsening and marine to nonmarine sequences. Moosebar bioturbated shales pass upward into turbidites and offshore storm deposits. Flow directions indicate a north-dipping paleoslope. A second coarsening-upward sequence at the top of the Moosebar and base of the Gates terminates in a lenticular fluvial conglomerate up to 30 m thick, which is overlain by coals, carbonaceous mudstones, and sandstones. Above the carbonaceous zone, fluvial conglomerates in the south grade into beach conglomerates northward. The upper part of the beach conglomerate consists of exposed three-dimensional storm berms, at least 500 m long, up to 1.5 m high, with wavelengths of 12 to 24 m. The berms trend east-west. Seaward of the conglomerate beach are herringbone cross-bedded (tidal) sandstones with a marine trace fauna. Graded sharp-based conglomerates also are present. Farther north, at the same stratigraphic level, is a series of partly overlapping conglomerate bars up to 5 m thick and 40 to 50 m across. The tops of these bars are covered with storm-formed symmetric conglomeratic dunes. Data suggest that four major environments (fluvial, beach, offshore conglomerate bars, and offshore graded storm conglomerates) should be identifiable and predictable in the subsurface. (JMT)

Leckie, D.A., Walker, R.G.

1982-02-01

13

Equivalent Fractions!  

NSDL National Science Digital Library

How good at determining equivalent fractions are you? Test your skills with these various fraction games to find out! You have recently been learning about fractions and their equivalency. Try this game to test your knowledge of Equivalent Fractions!! Be sure to notice the "hints" under some of the questions to help you get the correct answer. Good Luck! Continue to master your skills by playing the Dirt Bike Proportions! game. How quickly you ...

Pearce, Ms.

2011-11-06

14

Equivalent Fractions  

NSDL National Science Digital Library

In this interactive activity a user identifies two pairs of equivalent fractions for a given random fraction or one of the player's own and the user creates their representations by dividing and shading either a square or circular region. The fractions are shown as locations on the number line and their equivalency is demonstrated when they are at the same point. The user has the ability to construct a table of equivalent fractions. Instructions and exploration questions are given.

2011-01-01

15

Equivalent Fractions  

NSDL National Science Digital Library

What is an equivalent fraction? Students, I want you to create song about fractions. Here is a fraction song video to help you get and idea. Remember your song should be at least five sentences long. Math Song- Equivalent Fractions Students, I want you to click on the website below and the play the fraction game. Let's see how many ...

Ogle, Miss

2012-04-05

16

Evaluating steam trap performance  

Microsoft Academic Search

This paper presents a method for evaluating the performance level of steam traps by preparing an economic analysis of several types to determine the equivalent uniform annual cost. A series of tests on steam traps supplied by six manufacturers provided data for determining the relative efficiencies of each unit. The comparison was made using a program developed for the Texas

Fuller

1985-01-01

17

Evaluating steam trap performance  

SciTech Connect

This paper presents a method for evaluating the performance level of steam traps by preparing an economic analysis of several types to determine the equivalent uniform annual cost. A series of tests on steam traps supplied by six manufacturers provided data for determining the relative efficiencies of each unit. The comparison was made using a program developed for the Texas Instruments T1-59 programmable calculator to evaluate overall steam trap economics.

Fuller, N.Y.

1985-08-08

18

Equivalent Fractions  

NSDL National Science Digital Library

In this NCTM iOS app a user identifies equivalent fractions for a given random fraction or one of the player's own. The user creates their representations by dividing and shading either a square or circular region. The fractions are shown as locations on the number line and their equivalency is demonstrated when they are at the same point. The user has the ability to construct a table of equivalent fractions. This app is related to an Illuminations activity and an Android app that are cataloged separately.

2012-08-10

19

Equivalent Fractions  

NSDL National Science Digital Library

In this NCTM Android app a user identifies equivalent fractions for a given random fraction or one of the player's own. The user creates their representations by dividing and shading either a square or circular region. The fractions are shown as locations on the number line and their equivalency is demonstrated when they are at the same point. The user has the ability to construct a table of equivalent fractions. This app is related to an Illuminations activity and an iOS app that are cataloged separately.

2012-07-31

20

Equivalence-Equivalence: Matching Stimuli with Same Discriminative Functions  

ERIC Educational Resources Information Center

Previous studies have shown that after being trained on A-B and A-C match-to-sample tasks, adults match not only same-class B and C stimuli (equivalence) but also BC compounds with same-class elements and with different-class elements (BC-BC). The assumption was that the BC-BC performances are based on matching equivalence and nonequivalence…

Carpentier, Franck; Smeets, Paul M.; Barnes-Holmes, Dermot

2004-01-01

21

Matching Derived Functionally-Same Stimulus Relations: Equivalence-Equivalence and Classical Analogies  

ERIC Educational Resources Information Center

Previous studies have shown that, after being trained on A-B and A-C matching tasks, subjects match not only functionally-same B and C stimuli (stimulus equivalence), but also BC compounds with same-class elements and BC compounds with different-class elements (equivalence-equivalence). Similar performances are required in classical analogies (a :…

Carpentier, Franck; Smeets, Paul M.; Barnes-Holmes, Dermot; Stewart, Ian

2004-01-01

22

Magnetic Trapping - Trapped Radiation  

NSDL National Science Digital Library

This set of five web pages provides a non-mathematical introduction to the motion of charged particles in magnetic fields. These pages describe the "guiding center motion" which determines the motion of ions and electrons trapped in the Earth's magnetic field and in laboratory plasma devices. Also covered are gyration and mirroring, adiabatic invariance and drifts due to an electric field and gradients in the magnetic field intensity. This is part of the work "The Exploration of the Earth's Magnetosphere". A Spanish translation is available.

Stern, David

2005-04-27

23

Optical trapping  

PubMed Central

Since their invention just over 20 years ago, optical traps have emerged as a powerful tool with broad-reaching applications in biology and physics. Capabilities have evolved from simple manipulation to the application of calibrated forces on—and the measurement of nanometer-level displacements of—optically trapped objects. We review progress in the development of optical trapping apparatus, including instrument design considerations, position detection schemes and calibration techniques, with an emphasis on recent advances. We conclude with a brief summary of innovative optical trapping configurations and applications.

Neuman, Keir C.; Block, Steven M.

2006-01-01

24

Antihydrogen Trapped  

NASA Astrophysics Data System (ADS)

In 2010 the ALPHA collaboration succeeded in trapping antihydrogen atoms for the first time.ootnotetext``Trapped antihydrogen,'' G.B. Andresen et al., Nature 468, 673 (2010) Stored antihydrogen promises to be a unique tool for making high precision measurements of the structure of this first anti-atom. Achieving this milestone presented several substantial experimental challenges and this talk will describe how they were overcome. The unique design features of the ALPHA apparatus will be explained.ootnotetext``A Magnetic Trap for Antihydrogen Confinement,'' W. Bertsche et al., Nucl. Instr. Meth. Phys. Res. A 566, 746 (2006) These allow a high intensity positron source and an antiproton imaging detector similar to the one used in the ATHENAootnotetext``Production and detection of cold antihydrogen atoms,'' M.Amoretti et al., Nature 419, 456 (2002). experiment to be combined with an innovative magnet design of the anti-atom trap. This seeks to minimise the perturbations to trapped charged particles which may cause particle loss and heating.ootnotetext``Antihydrogen formation dynamics in a multipolar neutral anti-atom trap.'' G.B. Andresen et al., Phys. Lett. B 685, 141 (2010) The diagnostic techniques used to measure the diameter, number, density, and temperatures of both plasmas will be presented as will the methods developed to actively compress and cool of both plasma species to sizes and temperaturesootnotetext``Evaporative Cooling of Antiprotons to Cryogenic Temperatures,'' G.B. Andresen et al. Phys. Rev. Lett 105, 013003 (2010)^,ootnotetext``Compression of Antiproton Clouds for Antihydrogen Trapping,'' G. B. Andresen et al. Phys. Rev. Lett 100, 203401 (2008)^,ootnotetext``Autoresonant Excitation of Antiproton Plasmas,'' G.B. Andresen et al., Phys. Rev. Lett. 106, 025002 (2011) where trapping attempts with a reasonable chance of success can be tried. The results of the successful trapping experiments will be outlined as well as some subsequent experiments to improve the trapping rate and storage time.

Bowe, Paul D.

2011-06-01

25

Equivalence principles and electromagnetism  

NASA Technical Reports Server (NTRS)

The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

Ni, W.-T.

1977-01-01

26

Identifying Equivalent Fractions  

NSDL National Science Digital Library

This site helps students understand how to identify equivalent fractions by explaining what equivalent fractions are and how to compare two fractions to see if they are equivalent. There is also a list of fractions equivalent to 1/2, 1/3, 1/4, 1/5, and 2/5 so students can begin to see the pattern that emerges. Finally, the site presents an interactive game in which students can practice by naming the equivalent fraction to a given fraction.

Banfill, J. C.

2007-12-12

27

An Equivalent Gauge and the Equivalence Theorem  

NASA Astrophysics Data System (ADS)

I describe a novel covariant formulation of massive gauge theories in which the longitudinal polarization vectors do not grow with the energy. Therefore in the present formalism, differently from the ordinary one, the energy and coupling power-counting is completely transparent at the level of individual Feynman diagrams, with obvious advantages both at the conceptual and practical level. Since power-counting is transparent, the high-energy limit of the amplitudes involving longitudinal particles is immediately taken, and the Equivalence Theorem is easily demonstrated at all orders in perturbation theory. Since the formalism makes the Equivalence Theorem self-evident, and because it is based on a suitable choice of the gauge, we can call it an “Equivalent Gauge”.

Wulzer, Andrea

2014-08-01

28

4.NF Fraction Equivalence  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Explain why $\\frac{6}{10} = \\frac{60}{100}$. Draw a picture to illustrate your explanation....

29

Equivalent Fraction Pointer  

NSDL National Science Digital Library

This interactive Java applet helps users explore equivalent fractions through partitioning circles and squares. The applet provides a random fraction and the user creates one or two equivalent representations of that fraction by partitioning and coloring a square (or circle). The applet also plots the fraction on a number line and points from the shape to the number line displaying its equivalent value while the fraction is being built. Options include choice of circles or squares, one or two equivalent fractions, and a scoring feature allows users to keep track of the number correct.

2006-01-01

30

Equivalent Fraction Finder  

NSDL National Science Digital Library

This interactive Java applet helps users explore equivalent fractions through partitioning circles and squares. The applet provides a random fraction and the user creates one or two equivalent representations of that fraction by partitioning and coloring a square (or circle). The applet also plots the fraction on a number line and points from the shape to the number line displaying its equivalent value after the fraction is built. Options include choice of circles or squares, one or two equivalent fractions, and a scoring feature allows users to keep track of the number correct.

2006-01-01

31

Credit Traps  

Microsoft Academic Search

This paper studies the limitations of monetary policy transmission within a credit channel frame- work. We show that, under certain circumstances, the credit channel transmission mechanism fails in that liquidity injections by the central bank into the banking sector are hoarded and not lent out. We use the term ‘credit traps’ to describe such situations and show how they can

Efraim Benmelech; Nittai K. Bergman

2010-01-01

32

Steam trap  

Microsoft Academic Search

A steam trap is described for expelling large quantities of condensate held at low pressure and for self locking at pressures above a predetermined pressure. The process comprises: a body including an input port, and an output port; a chamber within the body communicating with the output port. The chamber has sidewalls and an annular shoulder adjacent the sidewalls; the

Kline

1987-01-01

33

Assessing Ricardian Equivalence  

Microsoft Academic Search

This paper reviews the literature on Ricardian equivalence. This hypothesis may be interpreted as a generalization to the short and the long run of the theories that put no weight on the real effects of public policies on aggregate demand. We argue that Ricardian equivalence relies on both the permanent income hypothesis and the fulfillment of the intertemporal government budget

Roberto Ricciuti

2003-01-01

34

Morita Equivalence and Duality.  

National Technical Information Service (NTIS)

It was shown by Connes, Douglas, Schwarz that one can compactify M(atrix) theory on noncommutative torus T(sub theta). The authors prove that compactifications on Morita equivalent tori are in some sense physically equivalent. This statement can be consid...

A. Schwarz

1998-01-01

35

Involute, minimal, outer, and increasingly trapped spheres  

NASA Astrophysics Data System (ADS)

Seven different refinements of trapped surfaces are proposed, each intended as potential stability conditions. This article concerns spherical symmetry, but each condition can be generalized. Involute trapped spheres satisfy a similar condition to minimal trapped spheres, which are strictly minimal with respect to the Kodama vector. There is also a weaker version of involute trapped spheres. Outer trapped spheres have positive surface gravity. Increasingly (future, respectively, past) trapped spheres generate spheres which are more trapped in a (future, respectively, past) causal direction, with three types: in any such causal direction, along the dual Kodama vector, and in some such causal direction. Assuming the null energy condition, the seven conditions form a strict hierarchy, in the above order. In static space-times, they reduce to three inequivalent definitions, namely, minimal, outer, and increasingly trapped spheres. For a widely considered class of so-called nice (or nondirty) black holes, minimal trapped and outer trapped become equivalent. Reissner-Nordström black holes provide examples of this, and that the increasingly trapped differs. Examples where all three refinements differ are provided by a simple family of dirty black holes parametrized by mass and singularity area.

Hayward, Sean A.

2010-01-01

36

Neutron dose equivalent meter  

DOEpatents

A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

1996-01-01

37

Salisbury hospital's steam trap success.  

PubMed

With the Carbon Reduction Commitment now fully in force, and the NHS tasked with achieving tough carbon emission reduction targets in line with both UK and EU mandates, healthcare estates teams across the country are seeking cost-effective ways to reduce energy consumption. Against this backdrop, Salisbury District Hospital has implemented a concerted energy-saving programme, key elements of which include replacing existing bucket steam traps with higher performing, lower maintenance, and more effective GEM venturi steam traps from Thermal Energy International (TEI), installing a new gas CHP engine, and looking into fitting a TEI condensate economiser system. PMID:21485315

Baillie, Jonathan

2011-03-01

38

Establishing Substantial Equivalence: Transcriptomics  

NASA Astrophysics Data System (ADS)

Regulatory authorities in Western Europe require transgenic crops to be substantially equivalent to conventionally bred forms if they are to be approved for commercial production. One way to establish substantial equivalence is to compare the transcript profiles of developing grain and other tissues of transgenic and conventionally bred lines, in order to identify any unintended effects of the transformation process. We present detailed protocols for transcriptomic comparisons of developing wheat grain and leaf material, and illustrate their use by reference to our own studies of lines transformed to express additional gluten protein genes controlled by their own endosperm-specific promoters. The results show that the transgenes present in these lines (which included those encoding marker genes) did not have any significant unpredicted effects on the expression of endogenous genes and that the transgenic plants were therefore substantially equivalent to the corresponding parental lines.

Baudo, María Marcela; Powers, Stephen J.; Mitchell, Rowan A. C.; Shewry, Peter R.

39

Trapping Electron Assisted Magnetic Recording  

Microsoft Academic Search

Moving towards 10 Tb\\/in2 areal density, finding a proper recording scheme with enough write-ability is the most challenging task of a magnetic recording system. Some recording schemes with enhanced write-ability, such as HAMR, MAMR, graded media, etc., have been proposed to achieve higher recording density. Here we propose a new alternative approach for enhanced writing-trapping electron assisted magnetic recording (TEAMR).

Tiejun Zhou; Zhimin Yuan; Siang Huei Leong; Boon Hao Low; Chun Lian Ong; Li Wang; Bo Liu; Choon Min Cheong; Shengbin Hu

2010-01-01

40

Everyday Mathematics Equivalent Fractions  

NSDL National Science Digital Library

This iOS app ($) provides students with practice and reinforcement of fraction concepts in a solitaire context. Users try to clear a board by matching cards displaying equivalent visual and numeric representations of fractions, while getting feedback and scoring points for accuracy. A tutorial with voice explains how to play.

2011-02-03

41

Comments on TNT Equivalence.  

National Technical Information Service (NTIS)

The term ''TNT Equivalence'' is used throughout the explosives and related industries to compare the effects of the output of a given explosive to that of TNT. This is done for technical design reasons in scaling calculation such as for the prediction of ...

P. W. Cooper

1994-01-01

42

Questioning the Equivalence Principle.  

National Technical Information Service (NTIS)

The Equivalence Principle (EP) is not one of the 'universal' principles of physics (like the Action Principle). It is a heuristic hypothesis which was introduced by Einstein in 1907, and used by him to construct his theory of General Relativity. In modern...

T. Damour

2001-01-01

43

Equivalent Crystal Planes Animation  

NSDL National Science Digital Library

This is a 3-D animation of equivalent crystal planes. It shows the Miller indices linking nodes as a corresponding binary family within braces. This animation is approximately 13 seconds in length and would be useful for understanding the conceptual/imaginary planes have on the crystal behavior.

2009-07-22

44

Five Equivalent d Orbitals  

ERIC Educational Resources Information Center

Amplifies and clarifies a previous paper on pyramidal d orbitals. Discusses two sets of pyramid d orbitals with respect to their maximum bond strength and their symmetry. Authors described the oblate and prolate pentagonal antiprisms arising from the two sets of five equivalent d orbitals. (RR)

Pauling, Linus; McClure, Vance

1970-01-01

45

Steam-trap capacities  

Microsoft Academic Search

Factors that affect steam-trap capacity are listed and include: trap inlet pressure, trap discharge pressure, subcooling of inlet condensate, static head of condensate on trap, design of the trap, design of the piping. Some of the things that a user might look for in a steam pipe are examined: low installed cost, low maintenance cost, low cost of owning, and

1985-01-01

46

Bullet Trap User's Guide.  

National Technical Information Service (NTIS)

This Bullet Trap User's Guide provides range management professionals with direction for choosing, installing, and maintaining bullet traps to solve metal migration, erosion, or safety problems on their outdoor small arms ranges. Bullet traps provide envi...

1996-01-01

47

Trapping ions in a segmented ring trap  

NASA Astrophysics Data System (ADS)

We demonstrate robust trapping in an ion trap which has a ring shaped RF node. Ions are back-side loaded through a small 10 ?m diameter loading hole and we have demonstrated thousands of complete circuits around the trap. Each circuit passes through 44 trapping zones; the trap has 89 independent DC control electrodes. Measurements of the tangential secular frequency indicate a weak dependence on the RF and the loading hole. The ion trap is fabricated using four metal layers, allowing for the inner islanded electrodes to be electrically routed underneath the trap with negligible effects on the trapped ions. [4pt] This work was supported by the Intelligence Advanced Research Projects Activity (IARPA). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Tabakov, B. P.; Sterk, J. D.; Benito, F.; Haltli, R.; Tigges, C. P.; Stick, D.; Blain, M. G.; Moehring, D. L.

2012-06-01

48

Micromachined Dust Traps  

NASA Technical Reports Server (NTRS)

Micromachined traps devised to capture dust particles for analysis without contaminating them. Based on micromachined structures retaining particles, rather than adhesives or greases interfering with scanning-electron-microscope analysis or x-ray imaging. Unlike maze traps and traps enmeshing particles in steel wool or similar materials, micromachined traps do not obscure trapped particles. Internal geometries of traps range from simple cones to U-shapes, all formed by etching silicon.

Bearman, Gregory H.; Bradley, James G.

1993-01-01

49

Plutonium 239 Equivalency Calculations  

SciTech Connect

This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CF{sub isotope}), or (2) 30-year-old weapons grade conversion factor (CF{sub 30 yr}) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference [1]. The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference [2]. The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

Wen, J

2011-05-31

50

Scheduling Tasks  

Microsoft Academic Search

\\u000a In this book, you’ve learned about various tasks you can perform to keep Ubuntu running smoothly. Although some of these tasks\\u000a require human intervention, many—such as backing up your important files or clearing the clutter from the tmp folder to ensure\\u000a that you always have enough free disk space— can be automated relatively easily by using the methods in this

Emilio Raggi; Keir Thomas; Trevor Parsons; Andy Channelle; Sander Vugt

51

Comments on TNT Equivalence  

SciTech Connect

The term ``TNT Equivalence`` is used throughout the explosives and related industries to compare the effects of the output of a given explosive to that of TNT. This is done for technical design reasons in scaling calculation such as for the prediction of blast waves, craters, and structural response, and is also used as a basis for government regulations controlling the shipping, handling and storage of explosive materials, as well as for the siting and design of explosive facilities. TNT equivalence is determined experimentally by several different types of tests, the most common of which include: plate dent, ballistic mortar, trauzl, sand crush, and air blast. All of these tests do not necessarily measure the same output property of the sample explosive. As examples of this, some tests depend simply upon the CJ pressure, some depend upon the PV work in the CJ zone and in the Taylor wave behind the CJ plane, some are functions of the total work which includes that from secondary combustion in the air mixing region of the fireball and are acutely effected by the shape of the pressure-time profile of the wave. Some of the tests incorporate systematic errors which are not readily apparent, and which have a profound effect upon skewing the resultant data. Further, some of the tests produce different TNT Equivalents for the same explosive which are a function of the conditions at which the test is run. This paper describes the various tests used, discusses the results of each test and makes detailed commentary on what the test is actually measuring, how the results may be interpreted, and if and how these results can be predicted by first principals based calculations. Extensive data bases are referred to throughout the paper and used in examples for each point in the commentaries.

Cooper, P.W.

1994-07-01

52

Charges trapped throughout the oxide and their impact on the Fowler-Nordheim current in MOS devices  

Microsoft Academic Search

We calculate the discrepancy ratio of gate voltage shift between charge trapped throughout the oxide and its equivalent charge density and centroid. The trapped charge density is underestimated if we extract trapped charge and its centroid from the measured lateral gate voltage shift without considering the transmission coefficient change due to charge trapped within a tunneling distance. For the thin

Pon S. Ku; Dieter K. Schroder

1994-01-01

53

Ion Trap Mass Spectrometry  

SciTech Connect

This chapter describes research conducted in a few research groups in the 1990s in which RF quadrupole ion trap mass spectrometers were coupled to a powerful atomic ion source, the inductively coupled plasma used in conventional ICP-MS instruments. Major section titles for this chapter are: RF Quadrupole Ion Traps Features of RF Quadrupole Ion Trap Mass Spectrometers Selective Ion Trapping methods Inductively Coupled Plasma Source Ion Trap Mass Spectrometers

Eiden, Greg C.

2005-09-01

54

Establishing Substantial Equivalence: Proteomics  

NASA Astrophysics Data System (ADS)

Wheat is a major crop in world agriculture and is consumed after processing into a range of food products. It is therefore of great importance to determine the consequences (intended and unintended) of transgenesis in wheat and whether genetically modified lines are substantially equivalent to those produced by conventional plant breeding. Proteomic analysis is one of several approaches which can be used to address these questions. Two-dimensional PAGE (2D PAGE) remains the most widely available method for proteomic analysis, but is notoriously difficult to reproduce between laboratories. We therefore describe methods which have been developed as standard operating procedures in our laboratory to ensure the reproducibility of proteomic analyses of wheat using 2D PAGE analysis of grain proteins.

Lovegrove, Alison; Salt, Louise; Shewry, Peter R.

55

Random Walk Theory of a Trap-Controlled Hopping Transport Process  

Microsoft Academic Search

A random walk theory of hopping motion in the presence of a periodic distribution of traps is presented. The solution of the continuous-time random walk equations is exact and valid for arbitrary intersite interactions and trap concentration. The treatment is shown to be equivalent to an exact solution of the master equation for this trapping problem. These interactions can be

H. Scher; C. H. Wu

1981-01-01

56

Acute Alcohol Effects on Repetition Priming and Word Recognition Memory with Equivalent Memory Cues  

ERIC Educational Resources Information Center

Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words…

Ray, Suchismita; Bates, Marsha E.

2006-01-01

57

Molecular electronics of the Dionaea muscipula trap  

PubMed Central

Transmission of electrical charge between a lobe and the midrib causes closure of the trap and induces an electrical signal propagating between a lobe and a midrib. The Venus flytrap can accumulate small subthreshold charges, and when the threshold value is reached, the trap closes. The cumulative character of electrical stimuli points to the existence of short-term electrical memory in the Venus flytrap. We investigated the electrical properties of the upper leaf of the Venus flytrap and proposed the equivalent electrical circuit in agreement with the experimental data.

Carrell, Holly; Markin, Vladislav S

2009-01-01

58

A Better Fly Trap  

NSDL National Science Digital Library

In this activity, learners observe fly behavior and then build a flytrap. They make more observations, compare the effectiveness of different traps, and modify their traps to increase their effectiveness. In doing so, learners consider what variables make for an effective trap as well as learning how to study the behavior of an animal. Even pesky flies provide an interesting challenge.

Science, Lawrence H.

1979-01-01

59

Thermostatic steam traps  

Microsoft Academic Search

A thermostatic steam trap is described comprising: a passageway for fluid flow; two connections constituting opposite ends of the passageway; a valve that opens and closes the trap having a valve seat disposed in the passageway; and a temperature-responsive element carrying a movable part of the valve that co-operates with the valve seat to open and close the trap; either

Dewhirst

1987-01-01

60

Improvements to Combinational Equivalence Checking  

Microsoft Academic Search

The paper explores several ways to improve the speed and capacity of combinational equivalence checking based on Boolean satisfiability (SAT). State-of-the-art methods use simulation and BDD\\/SAT sweeping on the input side (i.e. proving equivalence of some internal nodes in a topological order), interleaved with attempts to run SAT on the output (i.e. proving equivalence of the output to constant 0).

A. Mishchenko; S. Chatterjee; R. Brayton; N. Een

2006-01-01

61

Trap centers in molybdates  

NASA Astrophysics Data System (ADS)

Charge carrier trapping centers have been studied in molybdates CaMoO4, SrMoO4 and PbMoO4 with the scheelite crystal structure as well as in ZnMoO4, which crystallize in a-ZnMoO4 structural type. The trap parameters such as activation energies and frequency factors have been determined. It is shown for the first time that both electrons and holes are trapped by the elements of regular crystal structure in ZnMoO4. The effect of the charge carrier trapping on luminescence properties is demonstrated. Potential influence of the traps on the scintillation process is discussed.

Spassky, D. A.; Nagirnyi, V.; Mikhailin, V. V.; Savon, A. E.; Belsky, A. N.; Laguta, V. V.; Buryi, M.; Galashov, E. N.; Shlegel, V. N.; Voronina, I. S.; Zadneprovski, B. I.

2013-10-01

62

Estimating equivalence with quantile regression.  

PubMed

Equivalence testing and corresponding confidence interval estimates are used to provide more enlightened statistical statements about parameter estimates by relating them to intervals of effect sizes deemed to be of scientific or practical importance rather than just to an effect size of zero. Equivalence tests and confidence interval estimates are based on a null hypothesis that a parameter estimate is either outside (inequivalence hypothesis) or inside (equivalence hypothesis) an equivalence region, depending on the question of interest and assignment of risk. The former approach, often referred to as bioequivalence testing, is often used in regulatory settings because it reverses the burden of proof compared to a standard test of significance, following a precautionary principle for environmental protection. Unfortunately, many applications of equivalence testing focus on establishing average equivalence by estimating differences in means of distributions that do not have homogeneous variances. I discuss how to compare equivalence across quantiles of distributions using confidence intervals on quantile regression estimates that detect differences in heterogeneous distributions missed by focusing on means. I used one-tailed confidence intervals based on inequivalence hypotheses in a two-group treatment-control design for estimating bioequivalence of arsenic concentrations in soils at an old ammunition testing site and bioequivalence of vegetation biomass at a reclaimed mining site. Two-tailed confidence intervals based both on inequivalence and equivalence hypotheses were used to examine quantile equivalence for negligible trends over time for a continuous exponential model of amphibian abundance. PMID:21516905

Cade, Brian S

2011-01-01

63

Testing Model Nesting and Equivalence  

ERIC Educational Resources Information Center

When using existing technology, it can be hard or impossible to determine whether two structural equation models that are being considered may be nested. There is also no routine technology for evaluating whether two very different structural models may be equivalent. A simple nesting and equivalence testing (NET) procedure is proposed that uses…

Bentler, Peter M.; Satorra, Albert

2010-01-01

64

On the ambient dose equivalent  

Microsoft Academic Search

Two different concepts of ambient dose equivalent can be extracted, in the case of photons, from ICRU Reports. The characteristics of both are analysed considering the monitoring requirements. Furthermore, the utility of the ambient dose equivalent is discussed in a more general way on the basis of the most recent developments in radiation protection. We conclude that the ambient dose

A. Ferrari; M. Pelliccioni

1994-01-01

65

Large Nc equivalence and baryons  

NASA Astrophysics Data System (ADS)

In the large Nc limit, gauge theories with different gauge groups and matter content sometimes turn out to be “large Nc equivalent,” in the sense of having a set of coincident correlation functions. Large Nc equivalence has mainly been explored in the glueball and meson sectors. However, a recent proposal to dodge the fermion sign problem of QCD with a quark number chemical potential using large Nc equivalence motivates investigating the applicability of large Nc equivalence to correlation functions involving baryon operators. Here we present evidence that large Nc equivalence extends to the baryon sector, under the same type of symmetry realization assumptions as in the meson sector, by adapting the classic Witten analysis of large Nc baryons.

Blake, Mike; Cherman, Aleksey

2012-09-01

66

A-SSE Equivalent Expressions  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Find a value for $a$, a value for $k$, and and a value for $n$ so that (3x + 2) (2x - 5) = ax^2 + kx + n....

67

Trapping rate dependence on the trap size in one dimension  

NASA Astrophysics Data System (ADS)

The one-dimensional trapping problem is revisited with emphasis on the role of the size of the traps. It is discovered that the process rate is dependent on the trap size whenever the traps are correlated. Qualitatively, the effect is manifested as a slowdown or an acceleration of trapping with an enlargement of traps, according to trap attraction or repulsion, respectively. The dependence is studied in detail for a particular model. (c) 1995 The American Physical Society

Bogachev, L. V.; Makhnovskii, Yu. A.; Berezhkovskii, A. M.

1995-12-01

68

Steam traps: simple but important  

SciTech Connect

An overeview of various steam trap designs and their characteristics is presented. The basic uses of each design are discussed. The need for steam traps is reviewed and it is stressed that steam traps (which do not require operator attendance) is the simplest and most cost effective means of allowing condensate to drain away from critical areas. The four basic types of steam traps are described. These are: (1) inverted bucket traps; (2) float traps; (3) thermodynamic traps; and (4) condensate load traps. Advantages and disadvantages of each type of steam trap are discussed as well as cost considerations. Considerations in usage of each type of trap are pointed out. (MJJ)

Hammond, H.

1981-03-01

69

Ambient dose equivalent and directional dose equivalent instruments.  

National Technical Information Service (NTIS)

According to definitions of the new operational radiation quantities for environmental (area) monitoring recommended by the International Commission of Radiation Units and Measurements (ICRU) report 39, a spherical ambient dose equivalent meter and a para...

Jin Hua

1991-01-01

70

Ecological and evolutionary traps  

USGS Publications Warehouse

Organisms often rely on environmental cues to make behavioral and life-history decisions. However, in environments that have been altered suddenly by humans, formerly reliable cues might no longer be associated with adaptive outcomes. In such cases, organisms can become 'trapped' by their evolutionary responses to the cues and experience reduced survival or reproduction. Ecological traps occur when organisms make poor habitat choices based on cues that correlated formerly with habitat quality. Ecological traps are part of a broader phenomenon, evolutionary traps, involving a dissociation between cues that organisms use to make any behavioral or life-history decision and outcomes normally associated with that decision. A trap can lead to extinction if a population falls below a critical size threshold before adaptation to the novel environment occurs. Conservation and management protocols must be designed in light of, rather than in spite of, the behavioral mechanisms and evolutionary history of populations and species to avoid 'trapping' them.

Schlaepfer, M.A.; Runge, M.C.; Sherman, P.W.

2002-01-01

71

Slowwavematurationonavisualworkingmemory task.  

PubMed

The purpose of the present study is to analyze how the Slow Wave develops in the retention period on a visual Delayed Match-to-Sample task performed by 170 subjects between 6 and 26years old, divided into 5 age groups. In addition, a neuropsychological test (Working Memory Test Battery for Children) was correlated with this Event Related Potential (ERP) in order to observe possible relationships between Slow Wave maturation and the components of Baddeley and Hitch's Working Memory model. The results showed a slow negativity during the retention period in the posterior region in all the age groups, possibly resulting from sustained neural activity related to the visual item presented. In the anterior region, a positive slow wave was observed in the youngest subjects. Dipole analysis suggests that this fronto-central positivity in children (6-13years old) consists of the positive side of the posterior negativity, once these subjects only needed two posterior dipoles to explain almost all the neural activity. Negative correlations were shown between the Slow Wave and the Working Memory Test Battery for Children, indicating a commonality in assessing Working Memory with the Slow Wave and the neuropsychological testing. PMID:24859090

Barriga-Paulino, Catarina I; Rodríguez-Martínez, Elena I; Rojas-Benjumea, Ma Ángeles; Gómez, Carlos M

2014-07-01

72

Morita equivalence of noncommutative supertori  

NASA Astrophysics Data System (ADS)

In this paper we study the extension of Morita equivalence of noncommutative tori to the supersymmetric case. The structure of the symmetry group yielding Morita equivalence appears to be intact but its parameter field becomes supersymmetrized having both body and soul parts. Our result is mainly in the two dimensional case in which noncommutative supertori have been constructed recently: The group SO(2,2,Z0), where Z0 denotes Grassmann even number whose body part belongs to Z, yields Morita equivalent noncommutative supertori in two dimensions.

Chang-Young, Ee; Kim, Hoil; Nakajima, Hiroaki

2010-06-01

73

Morita equivalence of noncommutative supertori  

SciTech Connect

In this paper we study the extension of Morita equivalence of noncommutative tori to the supersymmetric case. The structure of the symmetry group yielding Morita equivalence appears to be intact but its parameter field becomes supersymmetrized having both body and soul parts. Our result is mainly in the two dimensional case in which noncommutative supertori have been constructed recently: The group SO(2,2,V{sub Z}{sup 0}), where V{sub Z}{sup 0} denotes Grassmann even number whose body part belongs to Z, yields Morita equivalent noncommutative supertori in two dimensions.

Chang-Young, Ee [Department of Physics, Sejong University, Seoul 143-747 (Korea, Republic of); Kim, Hoil [Department of Mathematics, Kyungpook National University, Taegu 702-701 (Korea, Republic of); Nakajima, Hiroaki [Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2010-06-15

74

Applications of microelectromagnetic traps.  

PubMed

Microelectromagnetic traps (METs) have been used for almost two decades to manipulate magnetic fields. Different trap geometries have been shown to produce distinct magnetic fields and field gradients. Initially, microelectromagnetic traps were used mainly to separate and concentrate magnetic material at small scales. Recently such traps have been implemented for unique applications, for example filterless bioseparations, inductive heat generation, and biological detection. In this review, we describe recent reports in which MET geometry, current density, or external fields have been used. Descriptions of recent applications in which METs have been used to develop sensors, manipulate DNA, or block ion current are also provided. PMID:22562543

Basore, Joseph R; Baker, Lane A

2012-06-01

75

Equivalency Detectives: Fractions and Decimals!  

NSDL National Science Digital Library

This is a lesson intended to reinforce students' ability to find equivalent fractions and decimals. The lesson requires prior essential vocabulary knowledge, and a basic understanding of converting fractions to decimals and decimals to fractions (specifically tenths and hundredths).

Magdaleno, Maribel

2012-07-17

76

Equivalency Theory and Distance Education.  

ERIC Educational Resources Information Center

Discusses distance education and the need for an accepted theory. Highlights include theories of independent study; theory of industrialization of teaching; theory of interaction and communication; and equivalency theory that is based on local control, personalized instruction, and telecommunications. (LRW)

Simonson, Michael

1999-01-01

77

Tissue Engineered Human Skin Equivalents  

PubMed Central

Human skin not only serves as an important barrier against the penetration of exogenous substances into the body, but also provides a potential avenue for the transport of functional active drugs/reagents/ingredients into the skin (topical delivery) and/or the body (transdermal delivery). In the past three decades, research and development in human skin equivalents have advanced in parallel with those in tissue engineering and regenerative medicine. The human skin equivalents are used commercially as clinical skin substitutes and as models for permeation and toxicity screening. Several academic laboratories have developed their own human skin equivalent models and applied these models for studying skin permeation, corrosivity and irritation, compound toxicity, biochemistry, metabolism and cellular pharmacology. Various aspects of the state of the art of human skin equivalents are reviewed and discussed.

Zhang, Zheng; Michniak-Kohn, Bozena B.

2012-01-01

78

Big brains are not enough: performance of three parrot species in the trap-tube paradigm.  

PubMed

The trap-tube task has become a benchmark test for investigating physical causality in vertebrates. In this task, subjects have to retrieve food out of a horizontal tube using a tool and avoiding a trap hole in the tube. Great apes and corvids succeeded in this task. Parrots with relative brain volumes comparable to those of corvids and primates also demonstrate high cognitive abilities. We therefore tested macaws, a cockatoo, and keas on the trap-tube paradigm. All nine parrots failed to solve the task. In a simplified task, trap tubes with a slot inserted along the top were offered. The slot allowed the birds to move the reward directly with their bills. All but one individual solved this task by lifting the food over the trap. However, the parrots failed again when they were prevented from lifting the reward, although they anticipated that food will be lost when moved into the trap. We do not think that the demanding use of an external object is the main reason for the parrots' failure. Moreover, we suppose these parrots fail to consider the trap's position in the beginning of a trial and were not able to stop their behaviour and move the reward in the trap's opposite direction. PMID:20814805

Liedtke, Jannis; Werdenich, Dagmar; Gajdon, Gyula K; Huber, Ludwig; Wanker, Ralf

2011-01-01

79

Transfer of a conditional ordering response through conditional equivalence classes  

PubMed Central

Eight adult humans were taught conditional discriminations in a matching-to-sample format that led to the formation of two four-member equivalence classes. When subjects were taught to select one comparison stimulus from each class in a set order, they then ordered all other members of the equivalence classes without explicit training. When the ordering response itself was brought under conditional control, conditional sequencing also transferred to all other members of the two equivalence classes. When the conditional discriminations in the matching-to-sample task were brought under higher order conditional control, the eight stimulus members were arranged into four conditional equivalence classes. Both ordering and conditional ordering transferred to all members of the four conditional equivalence classes; for some subjects this occurred without a typical test for equivalence. One hundred twenty untrained sequences emerged from eight trained sequences for all subjects. Transfer of functions through equivalence classes may contribute to a behavior-analytic approach to semantics and generative grammar.

Wulfert, Edelgard; Hayes, Steven C.

1988-01-01

80

The low skill trap  

Microsoft Academic Search

Recently, it has become popular to argue that certain workers have fallen into a trap in which they have poor skills, few job opportunities and a low return on training, while others have not. This paper demonstrates how such a trap can occur within a simple matching model with rent sharing. Rent sharing diminishes the worker's incentive to acquire skills;

Ken Burdett; Eric Smith

2002-01-01

81

Fruit Fly Trap!  

NSDL National Science Digital Library

In this activity, compare the effectiveness of different traps to catch fruit flies. Is apple cider vinegar or white vinegar better at trapping these little insects? Use this activity to practice the scientific method or as a science fair project. This activity guide includes a step-by-step instructional video.

Center, Saint L.

2013-01-17

82

Steam trap monitor  

Microsoft Academic Search

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and

Ryan

1987-01-01

83

Steam trap monitor  

Microsoft Academic Search

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more

Ryan; Michael J

1988-01-01

84

Steam trap monitor  

Microsoft Academic Search

For use in a closed steam system, apparatus coupled to a stream trap by means of a pipe and located downstream therefrom for monitoring the steam trap, the apparatus comprising: first sensing means in the pipe for determining the heat energy of a condensate flow in the pipe; second sensing means in the pipe for determining the heat energy of

Ryan

1988-01-01

85

Single beam acoustic trapping  

Microsoft Academic Search

A single beam acoustic device, with its relatively simple scheme and low intensity, can trap a single lipid droplet in a manner similar to optical tweezers. Forces in the order of hundreds of nanonewtons direct the droplet toward the beam focus, within the range of hundreds of micrometers. This trapping method, therefore, can be a useful tool for particle manipulation

Jungwoo Lee; Shia-Yen Teh; Abraham Lee; Hyung Ham Kim; Changyang Lee; K. Kirk Shung

2009-01-01

86

Neutrophil extracellular traps  

PubMed Central

Cancers prime neutrophils to release extracellular DNA traps through the systemic release of granulocyte colony-stimulating factor (G-CSF). We recently showed that these circulating neutrophil extracellular traps (NETs) promote the establishment of a pro-thrombotic state. The role of NETs in cancer biology and tumor progression may prove much more than an unfortunate side effect of cancer.

Demers, Melanie; Wagner, Denisa D.

2013-01-01

87

Chapter 12: Trapped Electrons as Electrical (Quantum) Circuits  

NASA Astrophysics Data System (ADS)

In this chapter, we present a detailed model of the equivalent electric circuit of a single trapped particle in a coplanar-waveguide (CPW) Penning trap. The CPW-trap, which is essentially a section of coplanar-waveguide transmission-line, is designed to make it compatible with circuit-quantum electrodynamic architectures. This will enable a single trapped electron, or geonium atom, as a potential building block of microwave quantum circuits. The model of the trapped electron as an electric circuit was first introduced by Hans Dehmelt in the 1960s. It is essential for the description of the electronic detection using resonant tank circuits. It is also the basis for the description of the interaction of a geonium atom with other distant quantum systems through electrical (microwave) signals.

Verdú, José

2014-01-01

88

Optically programmable excitonic traps  

PubMed Central

With atomic systems, optically programmed trapping potentials have led to remarkable progress in quantum optics and quantum information science. Programmable trapping potentials could have a similar impact on studies of semiconductor quasi-particles, particularly excitons. However, engineering such potentials inside a semiconductor heterostructure remains an outstanding challenge and optical techniques have not yet achieved a high degree of control. Here, we synthesize optically programmable trapping potentials for indirect excitons of bilayer heterostructures. Our approach relies on the injection and spatial patterning of charges trapped in a field-effect device. We thereby imprint in-situ and on-demand electrostatic traps into which we optically inject cold and dense ensembles of excitons. This technique creates new opportunities to improve state-of-the-art technologies for the study of collective quantum behavior of excitons and also for the functionalisation of emerging exciton-based opto-electronic circuits.

Alloing, Mathieu; Lemaitre, Aristide; Galopin, Elisabeth; Dubin, Francois

2013-01-01

89

Nonlinear integrable ion traps  

SciTech Connect

Quadrupole ion traps can be transformed into nonlinear traps with integrable motion by adding special electrostatic potentials. This can be done with both stationary potentials (electrostatic plus a uniform magnetic field) and with time-dependent electric potentials. These potentials are chosen such that the single particle Hamilton-Jacobi equations of motion are separable in some coordinate systems. The electrostatic potentials have several free adjustable parameters allowing for a quadrupole trap to be transformed into, for example, a double-well or a toroidal-well system. The particle motion remains regular, non-chaotic, integrable in quadratures, and stable for a wide range of parameters. We present two examples of how to realize such a system in case of a time-independent (the Penning trap) as well as a time-dependent (the Paul trap) configuration.

Nagaitsev, S.; /Fermilab; Danilov, V.; /SNS Project, Oak Ridge

2011-10-01

90

Trapping radioactive ions  

NASA Astrophysics Data System (ADS)

Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

Kluge, H.-J.; Blaum, K.

2004-12-01

91

Equivalent damage: A critical assessment  

NASA Technical Reports Server (NTRS)

Concepts in equivalent damage were evaluated to determine their applicability to the life prediction of hot path components of aircraft gas turbine engines. Equivalent damage was defined as being those effects which influence the crack initiation life-time beyond the damage that is measured in uniaxial, fully-reversed sinusoidal and isothermal experiments at low homologous temperatures. Three areas of equivalent damage were examined: mean stress, cumulative damage, and multiaxiality. For each area, a literature survey was conducted to aid in selecting the most appropriate theories. Where possible, data correlations were also used in the evaluation process. A set of criteria was developed for ranking the theories in each equivalent damage regime. These criteria considered aspects of engine utilization as well as the theoretical basis and correlative ability of each theory. In addition, consideration was given to the complex nature of the loading cycle at fatigue critical locations of hot path components; this loading includes non-proportional multiaxial stressing, combined temperature and strain fluctuations, and general creep-fatigue interactions. Through applications of selected equivalent damage theories to some suitable data sets it was found that there is insufficient data to allow specific recommendations of preferred theories for general applications. A series of experiments and areas of further investigations were identified.

Laflen, J. R.; Cook, T. S.

1982-01-01

92

Dose equivalent measurements in mixed and time varying radiation fields around high-energy accelerators  

Microsoft Academic Search

Measurements of ambient dose equivalent in stray radiation fields behind the shielding of high-energy accelerators are a challenging task. Several radiation components (photons, neutrons, charged particles, muons, etc.), spanning a wide range of energies, contribute to the total dose equivalent. The radiation fields are produced by beam losses interacting with structural material during the acceleration or at the ejection to

S Mayer; T Otto

2003-01-01

93

Equivalent widths of 5 giants in 47 Tuc (Alves-Brito+, 2005)  

NASA Astrophysics Data System (ADS)

Equivalent widths (EW) measured for Fe I and Fe II lines using IRAF task SPLOT and DAOSPEC. Column one gives the wavelength, column two the atomic species. Columns three and four give the excitation potential (EP) and gf-values, respectively. Columns 5-9 give the measured equivalent widths for the five stars of the sample using IRAF, while Columns 10-14 give the equivalent widths obtained using DAOSPEC. (2 data files).

Alves-Brito, A.; Barbuy, B.; Ortolani, S.; Momany, I.; Hill, V.; Zoccali, M.; Renzini, A.; Minniti, D.; Pasquini, L.; Bica, E.; Rich, R. M.

2005-02-01

94

Behavioral Task Analysis.  

National Technical Information Service (NTIS)

This chapter begins by defining a few key concepts that are critical to understanding the nature of tasks and task analysis. A brief overview of the development of task analysis and the distinction between behavioral task analysis and cognitive task analy...

D. H. Andrews H. H. Bell I. W. Wulfeck K. Silber W. Foshay

2010-01-01

95

Equivalence relations, invariants, and normal forms  

Microsoft Academic Search

Foran equivalence relationE on thewords insome finite alphabet,we consider the recognition problem (decide whether two words are equivalent), the invariant problem (calculate a function constant on precisely the equivalence classes), the normal form problem (calculate a particular member of an equivalence class, given an arbitrary member) and the first member problem (calculate the first member of an equivalence class, given

Andreas Blass; Yuri Gurevich

1983-01-01

96

Simplifying steam trap selection  

SciTech Connect

In the current economic world order, there is an obligation to eliminate waste and conserve economic and natural resources. One trap blowing 100-lb of steam through a 1/4-in. orifice can cost more than $12,000 a year in wasted energy. Richard J. Debat of Armstrong International, Inc. explains the operating principles of the four basic types of steam traps as the first step in simplifying the selection process so the right trap can be specified for a given application.

Debat, R.J. (Armstrong International, Inc., Three Rivers, MI (United States))

1994-01-01

97

Preliminary Findings on the Effects of Self-Referring and Evaluative Stimuli on Stimulus Equivalence Class Formation  

ERIC Educational Resources Information Center

Thirty-two subjects completed 2 stimulus equivalence tasks using a matching-to-sample paradigm. One task involved direct reinforcement of conditional discriminations designed to produce derived relations between self-referring stimuli (e.g., me, myself, I) and positive evaluation words (e.g., whole, desirable, perfect). The other task was designed…

Merwin, Rhonda M.; Wilson, Kelly G.

2005-01-01

98

Methamphetamine Interagency Task Force.  

National Technical Information Service (NTIS)

The Methamphetamine Interagency Task Force was established in 1996 in response to a provision of the Comprehensive Methamphetamine Control Act. This report represents the 2-year effort of the Task Force presenting: the principles that have guided the Task...

2000-01-01

99

Representational Implications for Understanding Equivalence  

ERIC Educational Resources Information Center

Teachers and researchers have long recognized that students tend to misunderstand the equal sign as an operator; that is, a signal for "doing something" rather than a relational symbol of equivalence or quantity sameness. Students' equal sign misconception has been researched for more than thirty years (Weaver, 1971, 1973) with little refinement…

Capraro, Mary Margaret; Ding, Meixia; Matteson, Shirley; Capraro, Robert M.; Li, Xiaobao

2007-01-01

100

Children's equivalence judgments: Crossmapping effects  

Microsoft Academic Search

Preschoolers made numerical comparisons between sets with varying degrees of shared surface similarity. When surface similarity was pitted against numerical equivalence (i.e., crossmapping), children made fewer number matches than when surface similarity was neutral (i.e, all sets contained the same objects). Only children who understood the number words for the target sets performed above chance in the crossmapping condition. These

Kelly S. Mix

2008-01-01

101

Experiencing Equivalence but Organizing Order  

ERIC Educational Resources Information Center

The notion of equivalence relation is arguably one of the most fundamental ideas of mathematics. Accordingly, it plays an important role in teaching mathematics at all levels, whether explicitly or implicitly. Our success in introducing this notion for its own sake or as a means to teach other mathematical concepts, however, depends largely on our…

Asghari, Amir H.

2009-01-01

102

Multiple Functions in Equivalence Classes  

ERIC Educational Resources Information Center

Four experiments examined the effects of training a "drawing" response to each of three stimuli in a 5-member equivalence class. In Experiment 1 the stimuli were an arbitrary word, a shape, or a mathematical symbol. Subjects then were trained to draw a separate component of a stickman at each of the 3 stimuli. Subsequent tests for function…

McVeigh, Brian; Keenan, Mickey

2009-01-01

103

Equivalence to the Minimum Qualifications  

ERIC Educational Resources Information Center

In 1988 the Community College Reform Act (AB 1725) began a phase out of credentials in favor of a process for establishing minimum qualifications and the determination of equivalencies that are at least equal to the state-adopted minimum qualifications for a particular discipline. According to Education Code sections 87359 and 87360, someone…

Academic Senate for California Community Colleges, 2006

2006-01-01

104

Performance Preorder and Competitive Equivalence  

Microsoft Academic Search

.   A preorder based on execution speed, called performance preorder, is introduced for a simple process algebra with durational\\u000a actions. Two processes and are related -- if they have the same functionality (in this case, we have chosen strong bisimulation equivalence) and is at least as fast as . Hence, this preorder supports the stepwise refinement “from specification to implementation”

Flavio Corradini; Roberto Gorrieri; Marco Roccetti

1997-01-01

105

Venus fly trap  

NSDL National Science Digital Library

Time-lapse photos or video show progressions from the start of an event to the end of the event. These time-lapse photos illustrate the growth of a single Venus fly trap. Biological processes require time.

Paul Lenz (None;)

2006-01-26

106

Steam trap monitor  

DOEpatents

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

Ryan, M.J.

1987-05-04

107

Comparison of Traps Lighted by Photochemicals or Electric Bulbs for Sampling Warmwater Populations of Young Fish  

Microsoft Academic Search

This study examined whether larval and juvenile fish were attracted equivalently to traps lighted by either electric bulbs or photochemical light sticks. There were no statistically significant differences (P ? 0.05) in collection rates of bluegills Lepornis rnacrochirus and brook silversides Labidesthes sicculus by light type. Significantly more threadfin shad Dorosoma petenense occurred in chemical light traps, but it could

Lee A. Kissick

1993-01-01

108

Equivalence between Bell inequalities and quantum Minority game  

Microsoft Academic Search

We show that, for a continuous set of entangled four-partite states, the task of max- imizing the payoff in the symmetric-strategy four-player quantum Minority game is equivalent to maximizing the violation of a four-particle Bell inequality with each observer choosing the same set of two dichotomic observables. We conclude the ex- istence of direct correspondences between (i) the payoff rule

Adrian P. Flitney; Maximilian Schlosshauer; Christian Schmid; Wieslaw Laskowski; Lloyd C. L. Hollenberg

109

Equivalence between Bell inequalities and quantum minority games  

Microsoft Academic Search

We show that, for a continuous set of entangled four-partite states, the task of maximizing the payoff in the symmetric-strategy four-player quantum Minority game is equivalent to maximizing the violation of a four-particle Bell inequality. We conclude the existence of direct correspondences between (i) the payoff rule and Bell inequalities, and (ii) the strategy and the choice of measured observables

Adrian P. Flitney; Maximilian Schlosshauer; Christian Schmid; Wieslaw Laskowski; Lloyd C. L. Hollenberg

2009-01-01

110

Simplifying steam trap selection  

Microsoft Academic Search

In the current economic world order, there is an obligation to eliminate waste and conserve economic and natural resources. One trap blowing 100-lb of steam through a 1\\/4-in. orifice can cost more than $12,000 a year in wasted energy. Richard J. Debat of Armstrong International, Inc. explains the operating principles of the four basic types of steam traps as the

Debat

1994-01-01

111

Single beam acoustic trapping  

PubMed Central

A single beam acoustic device, with its relatively simple scheme and low intensity, can trap a single lipid droplet in a manner similar to optical tweezers. Forces in the order of hundreds of nanonewtons direct the droplet toward the beam focus, within the range of hundreds of micrometers. This trapping method, therefore, can be a useful tool for particle manipulation in areas where larger particles or forces are involved.

Lee, Jungwoo; Teh, Shia-Yen; Lee, Abraham; Kim, Hyung Ham; Lee, Changyang; Shung, K. Kirk

2009-01-01

112

ROBOSPECT: Automated Equivalent Width Measurement  

NASA Astrophysics Data System (ADS)

The study of stellar abundances requires the analysis of spectral features. The two methods of analysis are spectral synthesis and equivalent width measurement. Spectral synthesis requires models and other inputs, which makes reproducing the synthetic spectra of other studies difficult. The equivalent width of a line is simply a geometric characteristic and is therefore an easily repeatable measurement between different sets of spectra for a given star, without needing to account for differing treatments of the physics of abundance analysis between studies. Equivalent width measurement is typically achieved by fitting a Gaussian or Voigt profile to a spectral line using software that usually requires user input. As different users may make different choices of the fitting parameters (such as the continuum placement), this introduces user-specific uncertainties into the fit quality. Automating this process allows the equivalent width measurement to be independent of these user-added uncertainties; however, there are few freely available programs that can accurately and precisely measure equivalent widths. We present a new program, ROBOSPECT, that does automate this measurement with minimal user interaction. This allows a consistent and repeatable set of measurements to be determined from the data without the added uncertainties due to user choices. ROBOSPECT is modular by design, allowing for different line models and continuum estimations to be selected based on the input spectrum. Comparing the results of ROBOSPECT to a sample of independently well measured spectral lines shows no systematic bias in the ROBOSPECT results, with a very tight scatter of 2.1 Å for a S/ 100 stellar spectrum. We illustrate the suitability of ROBOSPECT to line measurement by presenting a sample of test fits over a range of spectrum type and signal to noise.

Waters, Christopher Z.; Krugler, J. A.

2013-01-01

113

Optical trapping of nanoshells  

NASA Astrophysics Data System (ADS)

We investigate near-resonant trapping of Rayleigh particles in optical tweezers. Although optical forces due to a near-resonant laser beam have been extensively studied for atoms, the situation for larger particles is that the laser wavelength is far from any absorption resonance. Theory predicts, however, that the trapping force exerted on a Rayleigh particle is enhanced, and may be three to fifty times larger for frequencies near resonance than for frequencies far off resonance. The ability to selectively trap only particles with a given absorption peak may have many practical applications. In order to investigate near-resonant trapping we are using nanoshells, particles with a dielectric core and metallic coating that can exhibit plasmon resonances. The resonances of the nanoshells can be tuned by adjusting the ratio of the radius of the dielectric core, r1, to the overall radius, r2, which includes the thickness of the metallic coating. Our nanoshells, fabricated at Rice University, consist of a silica core with a gold coating. Using back focal plane detection, we measure the trap stiffness of a single focus optical trap (optical tweezers), from a diode laser at 853 nm for nanoshells with several different r1/r2 ratios.

Hester, Brooke C.; Crawford, Alice; Kishore, Rani B.; Helmerson, Kristian; Halas, Naomi J.; Levin, Carly

2007-09-01

114

Analysis of fault traps  

SciTech Connect

Unfaulted four-way-dip closures are the simplest and most attractive hydrocarbon traps. A single sealing lithology can provide both top and lateral seals. Seal risks are minimized with unfaulted four-way-dip closures. Unfortunately, most large four-way-drip closures have already been drilled, particularly in mature areas such as the US Gulf Coast. Exceptions may exist in deep water, at great depth, or in areas with significant lateral velocity variations, but for the most part, explorationists working mature areas are looking for either fault traps or stratigraphic traps. This article focuses on extensional fault systems, although many of the observations are applicable to compressional and strike-slip faulting. The following topics are discussed: mapping faults including discussions on the aliasing problem, fault shape, 3-D data, en echelon faults and the coherence cube; a general discussion of fault traps; juxtaposition traps and the use of ``Allan sections;`` and fault-sealing traps and the three mechanisms that cause fault-zone capillary properties to differ from unfaulted rock -- clay smear, grain crushing and diagenesis.

Brenneke, J.C. [Subsurface Consultants and Associates, Inc., Houston, TX (United States)

1995-12-01

115

Trapping kinetics in high trap density silicon nitride insulators  

Microsoft Academic Search

An analytical method has been developed to investigate the trapping kinetics of multiple trap levels in a silicon nitride insulator under very complex conditions. Solutions for the trapped-charge distribution are given for the case of a nonuniform single carrier current in an insulator having very strong charge trapping and various detrapping mechanisms such as Poole-Frenkel emission or photoionization. The trapped-charge

Steven B. Bibyk; Vikram J. Kapoor

1984-01-01

116

Trapping of Free Electrons in Multipole System  

NASA Astrophysics Data System (ADS)

In this paper, the effective Parameters in the confinement and trapping of fast electrons in plasma source Such as; plasma pressure, wall material of plasma chamber and magnetic mirror rate have been investigated with using Comsol & Geant4 code. The calculations are shown that the Multicusp magnetic field was effective the pressure less than 5 mTor, and the confinement effect becomes stronger with decreasing pressure. It is equivalent to a higher yield of output ions of plasma source. The number of fast electrons trapped in the magnetic field increases with increasing magnetic field intensity and using aluminum for wall material. Optimum conditions of confinement plasma, leading to increased the hot electron density, and ionization efficiency is increased. The results of investigations have demonstrated good correspondence with theoretical calculations, therefore there is the adequacy of the developed approach and the possibility to build more effective source ion on this basis.

Mahdavi, Mohammad; Khodadadi Azadboni, Fatemeh; Khodadadi Azadboni, Reza

2012-08-01

117

The Stanford equivalence principle program  

NASA Technical Reports Server (NTRS)

The Stanford Equivalence Principle Program (Worden, Jr. 1983) is intended to test the uniqueness of free fall to the ultimate possible accuracy. The program is being conducted in two phases: first, a ground-based version of the experiment, which should have a sensitivity to differences in rate of fall of one part in 10(exp 12); followed by an orbital experiment with a sensitivity of one part in 10(exp 17) or better. The ground-based experiment, although a sensitive equivalence principle test in its own right, is being used for technology development for the orbital experiment. A secondary goal of the experiment is a search for exotic forces. The instrument is very well suited for this search, which would be conducted mostly with the ground-based apparatus. The short range predicted for these forces means that forces originating in the Earth would not be detectable in orbit. But detection of Yukawa-type exotic forces from a nearby large satellite (such as Space Station) is feasible, and gives a very sensitive and controllable test for little more effort than the orbiting equivalence principle test itself.

Worden, Paul W., Jr.; Everitt, C. W. Francis; Bye, M.

1989-01-01

118

Switching Oxide Traps  

NASA Technical Reports Server (NTRS)

We consider radiation-induced charge trapping in SiO2 dielectric layers, primarily from the point of view of CMOS devices. However, SiO2 insulators are used in many other ways, and the same defects occur in other contexts. The key studies, which determined the nature of the oxide charge traps, were done primarily on gate oxides in CMOS devices, because that was the main radiation problem in CMOS at one time. There are two major reviews of radiation-induced oxide charge trapping already in the literature, which discuss the subject in far greater detail than is possible here. The first of these was by McLean et al. in 1989, and the second, ten years later, was intended as an update, because of additional, new work that had been reported. Basically, the picture that has emerged is that ionizing radiation creates electron-hole pairs in the oxide, and the electrons have much higher mobility than the holes. Therefore, the electrons are swept out of the oxide very rapidly by any field that is present, leaving behind any holes that escape the initial recombination process. These holes then undergo a polaron hopping transport toward the Si/SiO2 interface (under positive bias). Near the interface, some fraction of them fall into deep, relatively stable, long-lived hole traps. The nature and annealing behavior of these hole traps is the main focus of this paper.

Oldham, Timothy R.

2003-01-01

119

Information Leakage from Logically Equivalent Frames  

ERIC Educational Resources Information Center

Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no…

Sher, Shlomi; McKenzie, Craig R. M.

2006-01-01

120

Strong Shift Equivalence of $C^*$-correspondences  

Microsoft Academic Search

We define a notion of strong shift equivalence for $C^*$-correspondences and show that strong shift equivalent $C^*$-correspondences have strongly Morita equivalent Cuntz-Pimsner algebras. Our analysis extends the fact that strong shift equivalent square matrices with non-negative integer entries give stably isomorphic Cuntz-Krieger algebras.

PAUL S. MUHLY; David Pask; Mark Tomforde

2005-01-01

121

Strong shift equivalence of C *-correspondences  

Microsoft Academic Search

We define a notion of strong shift equivalence for C*-correspondences and show that strong shift equivalent C*-correspondences have strongly Morita equivalent Cuntz-Pimsner algebras. Our analysis extends the fact that strong shift\\u000a equivalent square matrices with non-negative integer entries give stably isomorphic Cuntz-Krieger algebras.

Paul S. Muhly; David Pask; Mark Tomforde

2008-01-01

122

Thermoelectrically cooled water trap  

DOEpatents

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

Micheels, Ronald H. (Concord, MA)

2006-02-21

123

Coastally Trapped Wind Reversals  

NSDL National Science Digital Library

This module provides a brief overview of Coastally Trapped Wind Reversals. This module starts with a forecast scenario that occurs along the California coast. The module then proceeds to describe the structure and climatology of these disturbances, as well as their synoptic and mesoscale evolution. The instruction concludes with a section on forecasting coastally trapped wind reversals. The module also includes a concise summary for quick reference and a final exam to test your knowledge. Like other modules in the Mesoscale Meteorology Primer, this module comes with audio narration, rich graphics, and a companion print version.

Spangler, Tim

2002-07-01

124

Conformal dynamical equivalence and applications  

NASA Astrophysics Data System (ADS)

The "Conformal Dynamical Equivalence" (CDE) approach is briefly reviewed, and some of its applications, at various astrophysical levels (Sun, Solar System, Stars, Galaxies, Clusters of Galaxies, Universe as a whole), are presented. According to the CDE approach, in both the Newtonian and general-relativistic theories of gravity, the isentropic hydrodynamic flows in the interior of a bounded gravitating perfect-fluid source are dynamically equivalent to geodesic motions in a virtual, fully defined fluid source. Equivalently, the equations of hydrodynamic motion in the former source are functionally similar to those of the geodesic motions in the latter, physically, fully defined source. The CDE approach is followed for the dynamical description of the motions in the fluid source. After an observational introduction, taking into account all the internal physical characteristics of the corresponding perfect-fluid source, and based on the property of the isentropic hydrodynamic flows (quite reasonable for an isolated physical system), we examine a number of issues, namely, (i) the classical Newtonian explanation of the celebrated Pioneer-Anomaly effect in the Solar System, (ii) the possibility of both the attractive gravity and the repulsive gravity in a non-quantum Newtonian framework, (iii) the evaluation of the masses - theoretical, dynamical, and missing - and of the linear dimensions of non-magnetized and magnetized large-scale cosmological structures, (iv) the explanation of the flat-rotation curves of disc galaxies, (v) possible formation mechanisms of winds and jets, and (vi) a brief presentation of a conventional approach - toy model to the dynamics of the Universe, characterized by the dominant collisional dark matter (with its subdominant luminous baryonic "contamination"), correctly interpreting the cosmological observational data without the need of the notions dark energy, cosmological constant, and universal accelerating expansion.

Spyrou, N. K.

2011-02-01

125

Equivalence principle in Chameleon models .  

NASA Astrophysics Data System (ADS)

Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting view based on an approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a test body with Eötvös type experiments and find that the chameleon field effect cannot account for current bounds.

Kraiselburd, L.; Landau, S.; Salgado, M.; Sudarsky, D.

126

Optimization of pheromone lure and trap characteristics for currant clearwing, Synanthedon tipuliformis.  

PubMed

Currant clearwing Synanthedon tipuliformis (Sesiidae) has been a pioneering and successful target of mating disruption in New Zealand, with virtually universal black currant industry adoption since c. 1990. Recent unexplained control failures using mating disruption lead to questions about pheromone efficacy. In this study, we have investigated the possible reasons for reduced control from mating disruption, and report improvements in trap catch based on pheromone loading and trap color. No differences were found in electrophysiological responses to pheromone components from two New Zealand populations. Male moth catches in traps baited with synthetic lures were disrupted in the presence of mating disruption dispensers ( > 99.99%) indicating no apparent barrier to efficacy from the pheromone formulation. Field behavioral observations confirmed this result. Male attraction to yellow delta traps was equivalent to green delta traps, but was greater than to red, black, blue, or white traps. Solid yellow delta traps were more attractive than black traps with yellow stripes, the latter designed to mimic the color pattern of the insect. Solid yellow funnel traps were less attractive than a composite of green, yellow, and white funnel traps. Trap catch increased as a function of pheromone loading, and trap color. In another experiment conducted in Tasmania, there was no difference in catch with single component [(E,Z)-2,13-octadecadienyl acetate] or two component lures [97% (E,Z)-2,13-octadecadienyl acetate:3% (E,Z)-3,13octadecadienyl acetate], refuting the suggestion of a different pheromone strain there. PMID:15856791

Suckling, D M; Gibb, A R; Burnip, G M; Snelling, C; de Ruiter, J; Langford, G; El-Sayed, A M

2005-02-01

127

Oil Formation and Trapping  

NSDL National Science Digital Library

This animation shows the successive stages in the formation of an oil reserve. In View 1, organic material settles, is buried, and is transformed by heat and pressure into oil. In View 2 an oil trap is formed: the area folds into an anticline, and oil migrates and accumulates in the anticline crest.

Marshak, Stephen; Company, W. W.

128

WATER-TRAPPED WORLDS  

SciTech Connect

Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO{sub 2} as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

Menou, Kristen [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

2013-09-01

129

Paul Trap Simulator Experiment  

NASA Astrophysics Data System (ADS)

The Paul Trap Simulator Experiment (PTSX) is a compact laboratory facility whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation over a large distance through an alternating-gradient transport system. The simulation is possible because the quadrupole electric fields of the cylindrical Paul trap exert radial forces on the charged particles that are analogous to the radial forces that a periodic focusing quadrupole magnetic field exert on the beam particles in the beam frame. By controlling the waveform applied to the walls of the trap, PTSX will explore physics issues such as beam mismatch, envelope instabilities, halo particle production, compression techniques, collective wave excitations, and beam profile effects. Initial experiments have concentrated on characterizing the cesium ion source and studying ``free-steaming" ions that travel directly from the ion source to the Faraday cup diagnostic. The aluminosilicate cesium source provides up to 30 ?A, which is greater than the estimated 300 pA required to load the trap to a density of 10^6 cm-3. Variation of the wall voltage and the oscillation frequency reveals the stability limit of the single particle orbits.

Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard

2002-11-01

130

Thermostatic steam trap  

Microsoft Academic Search

A thermostatic trap is described for a heating system having a feed pipe connected to a source of steam and a discharge pipe for discharge of condensate and comprising: housing means defining a volume and comprising a bowl shaped body, a removable cover therefor, a housing inlet pipe portion projecting from a side wall portion of the body and adapted

A. H. Anderson; A. E. Mac Nicol

1987-01-01

131

Steam trap monitor  

DOEpatents

A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

Ryan, Michael J. (Plainfield, IL)

1988-01-01

132

Unitary Penning traps  

NASA Astrophysics Data System (ADS)

We have constructed Penning traps in extremely compact forms, with unitary architectures that fully integrate NdFeB magnets (1.2 Tesla remnant magnetic field) within the electrode structure (occupying < 150 cm^3 assembled). A room-temperature apparatus has proven to be very useful in slowing and capturing ions extracted from an electron beam ion trap (EBIT).ootnotetextJ. N. Tan, S. M. Brewer, and N. D. Guise, to appear in Review of Scientific Instruments Here we present a two-magnet Penning trap designed to facilitate ion manipulation and optical experiments with stored ions. Some test results are presented. Experiments using this novel system are discussed in two presentations at this meeting.ootnotetextN.D. Guise, et al., ``Charge exchange and spectroscopy with isolated highly-charged ions,'' at this meeting.^,ootnotetextS. M. Brewer, et al., ``Observing forbidden radiative decay of highly-charged ions in a compact Penning trap,'' at this meeting. Unitary architecture can be particularly advantageous in small-instrument development (e.g., mass spectrometers) and in facilities or missions that have severe space constraints.

Tan, Joseph; Brewer, Samuel; Guise, Nicholas

2012-06-01

133

Practical axial optical trapping  

PubMed Central

We describe a new method for calibrating optical trapping measurements in which tension is applied in the direction of the laser beam to a molecule tethered between a surface and an optically trapped bead. Specifically, we present a generally-applicable procedure for converting from the measured scattering intensity and the measured stage displacement to applied tension and bead-coverslip separation, using measurements of the light intensity scattered from an untethered, trapped bead. Our calibration accounts for a number of effects, including aberrations and the interference of forward-reflected bead-scattered light with the trapping beam. To demonstrate the accuracy of our method, we show measurements of the DNA force-versus-extension relation using a range of laser intensities, and show that these measurements match the expected extensible wormlike-chain (WLC) behavior. Finally, we also demonstrate a force-clamp, in which the tension in a tether is held fixed while the extension varies as a result of molecular events.

Mack, A. H.; Schlingman, D. J.; Regan, L.; Mochrie, S. G. J.

2012-01-01

134

Practical axial optical trapping  

NASA Astrophysics Data System (ADS)

We describe a new method for calibrating optical trapping measurements in which tension is applied in the direction of the laser beam to a molecule tethered between a surface and an optically trapped bead. Specifically, we present a generally-applicable procedure for converting from the measured scattering intensity and the measured stage displacement to applied tension and bead-coverslip separation, using measurements of the light intensity scattered from an untethered, trapped bead. Our calibration accounts for a number of effects, including aberrations and the interference of forward-reflected bead-scattered light with the trapping beam. To demonstrate the accuracy of our method, we show measurements of the DNA force-versus-extension relation using a range of laser intensities, and show that these measurements match the expected extensible wormlike-chain (WLC) behavior. Finally, we also demonstrate a force-clamp, in which the tension in a tether is held fixed while the extension varies as a result of molecular events.

Mack, A. H.; Schlingman, D. J.; Regan, L.; Mochrie, S. G. J.

2012-10-01

135

Water-trapped Worlds  

NASA Astrophysics Data System (ADS)

Although tidally locked habitable planets orbiting nearby M-dwarf stars are among the best astronomical targets to search for extrasolar life, they may also be deficient in volatiles and water. Climate models for this class of planets show atmospheric transport of water from the dayside to the nightside, where it is precipitated as snow and trapped as ice. Since ice only slowly flows back to the dayside upon accumulation, the resulting hydrological cycle can trap a large amount of water in the form of nightside ice. Using ice sheet dynamical and thermodynamical constraints, I illustrate how planets with less than about a quarter the Earth's oceans could trap most of their surface water on the nightside. This would leave their dayside, where habitable conditions are met, potentially dry. The amount and distribution of residual liquid water on the dayside depend on a variety of geophysical factors, including the efficiency of rock weathering at regulating atmospheric CO2 as dayside ocean basins dry up. Water-trapped worlds with dry daysides may offer similar advantages as land planets for habitability, by contrast with worlds where more abundant water freely flows around the globe.

Menou, Kristen

2013-09-01

136

Total radical trapping antioxidant potential (TRAP) and exercise  

Microsoft Academic Search

Summary The relationship between physical activity, physical fitness and total radical trapping antioxidant poten- tial (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross- sectional population study (n = 1600) using a two- stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols,

P. C. SHARPE; E. B. DULY; D. MacAULEY; E. E. McCRUM; C. MULHOLLAND; G. STOTT; C. A. G. BOREHAM; G. KENNEDY; A. E. EVANS; T. R. TRINICK

137

Dietary Supplements Task Force.  

National Technical Information Service (NTIS)

The Dietary Supplements Task Force was charged with examining the issues regarding dietary supplements and developing a regulatory framework for these products. To facilitate the orderly development of regulatory strategies, the Task Force divided the uni...

1992-01-01

138

NSI Security Task: Overview.  

National Technical Information Service (NTIS)

An overview is presented of the NASA Science Internet (NSI) security task. The task includes the following: policies and security documentation; risk analysis and management; computer emergency response team; incident handling; toolkit development; user c...

R. Tencati

1991-01-01

139

Build Your Own Insect Trap  

NSDL National Science Digital Library

Students design and construct devices to trap insects that are present in the area around the school. The objective is to ask the right design questions and conduct the right tests to determine if the traps work .

K-12 Rural Science Education Program,

140

Functional Task Test (FTT)  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.; Platts, Steven H.; Stenger, Michael B.; Lee, Stuart M.C.; Arzeno, Natalia; Feiveson, Alan H.; Ryder, Jeffrey; Garcia, Yamil; Guilliams, Mark E.

2009-01-01

141

Equivalent crystal theory of alloys  

NASA Technical Reports Server (NTRS)

Equivalent Crystal Theory (ECT) is a new, semi-empirical approach to calculating the energetics of a solid with defects. The theory has successfully reproduced surface energies in metals and semiconductors. The theory of binary alloys to date, both with first-principles and semi-empirical models, has not been very successful in predicting the energetics of alloys. This procedure is used to predict the heats of formation, cohesive energy, and lattice parameter of binary alloys of Cu, Ni, Al, Ag, Au, Pd, and Pt as functions of composition. The procedure accurately reproduces the heats of formation versus composition curves for a variety of binary alloys. The results are then compared with other approaches such as the embedded atom and lattice parameters of alloys from pure metal properties more accurately than Vegard's law is presented.

Bozzolo, Guillermo; Ferrante, John

1991-01-01

142

Electrostatic traps for dipolar excitons  

Microsoft Academic Search

We consider the design of two-dimensional electrostatic traps for dipolar indirect excitons. We show that the exciton dipole-dipole interaction, combined with the in-plane electric fields that arise due to the trap geometry, constrains the maximal density and lifetime of trapped excitons. We derive an analytic estimate of these values and determine their dependence on the trap geometry, thus suggesting the

Ronen Rapaport; Gang Chen; Steven Simon; Oleg Mitrofanov; Loren Pfeiffer; P. M. Platzman

2005-01-01

143

Steam traps: simple but important  

Microsoft Academic Search

An overeview of various steam trap designs and their characteristics is presented. The basic uses of each design are discussed. The need for steam traps is reviewed and it is stressed that steam traps (which do not require operator attendance) is the simplest and most cost effective means of allowing condensate to drain away from critical areas. The four basic

Hammond

1981-01-01

144

Nondestructive evaluation of steam traps  

Microsoft Academic Search

Many thermographers have touted infrared thermography as an effective maintenance tool for evaluating steam traps for years. However, several investigators have raised questions about thermal measurement's effectiveness in this application. This paper explores and compares infrared thermography and ultrasonic detection methods for steam trap testing and provides guidelines for a successful trap survey.

Gary L. Orlove

1999-01-01

145

Steam-trap users guide  

Microsoft Academic Search

Steam traps are an important element in the efficient operation of a steam system and in energy conservation. The high cost of producing and delivering steam mandates an effective steam-trap inspection and maintenance program at all applicable naval activities. A comprehensive program for steam-trap inspection and maintenance will pay for itself many times over in the cost of steam that

J. C. King; D. M. Sneed

1985-01-01

146

20 CFR 404.1526 - Medical equivalence.  

Code of Federal Regulations, 2013 CFR

...SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Medical Considerations § 404.1526 Medical equivalence. (a) What is medical equivalence? Your...

2013-04-01

147

Acoustic rainbow trapping  

NASA Astrophysics Data System (ADS)

Spatial modulation of sound velocity below the wavelength scale can introduce strong frequency-dependent acoustic responses in tailored composite materials, regardless the fact that most natural bulk materials have negligible acoustic dispersions. Here, for the first time, we experimentally demonstrate a metamaterial that traps broadband acoustic waves and spatially separates different frequency components, as the result of dispersion and wave velocity control by designed gradient subwavelength structures. The trapping positions can be predicted by the microscopic picture of balanced interplay between the acoustic resonance inside individual apertures and the mutual coupling among them. With the enhanced wave-structure interactions and the tailored frequency responses, such metamaterial allows precise spatial-spectral control of acoustic waves and opens new venue for high performance acoustic wave sensing, filtering, and nondestructive metrology.

Zhu, Jie; Chen, Yongyao; Zhu, Xuefeng; Garcia-Vidal, Francisco J.; Yin, Xiaobo; Zhang, Weili; Zhang, Xiang

2013-04-01

148

Radial cold trap  

DOEpatents

The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

Grundy, Brian R. (Greensburg, PA)

1981-01-01

149

Radial cold trap  

DOEpatents

The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

Grundy, B.R.

1981-09-29

150

Atom Trap Trace Analysis  

NASA Astrophysics Data System (ADS)

Since the invention of radiocarbon dating in 1949, trace analyses of long-lived cosmogenic isotopes have contributed to a wide range of scientific and technological areas. We have developed an analytical method called Atom Trap Trace Analysis (ATTA), in which individual atoms of the desired isotope are selectively captured and detected with a magneto-optical trap. ATTA possesses a superior selectivity and is used to analyze environmental radio-isotopes: ^81Kr, ^85Kr, and ^39Ar. These three isotopes have extremely low isotopic abundances in the range of 10-16 - 10-11, and cover a wide range of ages and applications. This work is supported by DOE, Office of Nuclear Physics, and by NSF, Division of Earth Sciences.

Lu, Zheng-Tian

2011-06-01

151

Ion trap mass spectrometry  

SciTech Connect

This paper reports on the quadrupole ion trap which is a mass spectrometer whose essential components can be held in one hand. But is has a mass range of about 10{sup 5} daltons per charge, provides molecular weight and structural information on biopolymers, and has the greatest sensitivity of all mass spectrometers. These features, however, has become available only within the past few years. They stem from an almost neglected 1958 invention, one in which interest was maintained by only a few research groups, notably those of John Todd at the University of Kent in England and Ray March at Trent University in Canada. Development of a new scanning method by George Stafford and his coworkers of Finnigan Corp. provided the impetus that led Finnigan to introduce a commercial ion trap in 1983. Since then, the device has been transformed from a simple gas chromatography detector to a high-performance mass spectrometer.

Cooks, R.G. (Purdue Univ. (US)); Glish, G.L.; Mc Luckey, S.A. (Oak Ridge National Lab. (US)); Kaiser, R.E. (Eli Lilly and Co. (US))

1991-03-25

152

Solar Trapped Particles  

NASA Astrophysics Data System (ADS)

High-energy particles (>10 MeV protons) can be trapped in large-scale coronal magnetic fields for periods of days to weeks. We model this trapping by following the adiabatic motions of particles in test fields, including the Schrijver-DeRosa PFSS models. These are available in a SolarSoft interface for the entire duration of the SOHO mission thus far. In spite of the complexity of the field, we find drift shells in which particles can circulate completely around the Sun, and thus conserve the third adiabatic invariant of motion well. In this work we study the morphology of the these drift shells, including their appearance as a function of phase in the solar cycle.

Hudson, Hugh S.; MacKinnon, A. L.; Frewen, S. F.

2009-05-01

153

Acoustic rainbow trapping  

PubMed Central

Spatial modulation of sound velocity below the wavelength scale can introduce strong frequency-dependent acoustic responses in tailored composite materials, regardless the fact that most natural bulk materials have negligible acoustic dispersions. Here, for the first time, we experimentally demonstrate a metamaterial that traps broadband acoustic waves and spatially separates different frequency components, as the result of dispersion and wave velocity control by designed gradient subwavelength structures. The trapping positions can be predicted by the microscopic picture of balanced interplay between the acoustic resonance inside individual apertures and the mutual coupling among them. With the enhanced wave-structure interactions and the tailored frequency responses, such metamaterial allows precise spatial-spectral control of acoustic waves and opens new venue for high performance acoustic wave sensing, filtering, and nondestructive metrology.

Zhu, Jie; Chen, Yongyao; Zhu, Xuefeng; Garcia-Vidal, Francisco J.; Yin, Xiaobo; Zhang, Weili; Zhang, Xiang

2013-01-01

154

Grid Task Execution  

NASA Technical Reports Server (NTRS)

IPG Execution Service is a framework that reliably executes complex jobs on a computational grid, and is part of the IPG service architecture designed to support location-independent computing. The new grid service enables users to describe the platform on which they need a job to run, which allows the service to locate the desired platform, configure it for the required application, and execute the job. After a job is submitted, users can monitor it through periodic notifications, or through queries. Each job consists of a set of tasks that performs actions such as executing applications and managing data. Each task is executed based on a starting condition that is an expression of the states of other tasks. This formulation allows tasks to be executed in parallel, and also allows a user to specify tasks to execute when other tasks succeed, fail, or are canceled. The two core components of the Execution Service are the Task Database, which stores tasks that have been submitted for execution, and the Task Manager, which executes tasks in the proper order, based on the user-specified starting conditions, and avoids overloading local and remote resources while executing tasks.

Hu, Chaumin

2007-01-01

155

Stimulus Equivalence: Testing Sidman's (2000) Theory  

ERIC Educational Resources Information Center

Sidman's (2000) theory regarding the origin of equivalence relations predicts that a reinforcing stimulus common to distinct equivalence classes must drop out of the equivalence relations. This prediction was tested in the present study by arranging class-specific reinforcers, R1 and R2, following correct responding on the prerequisite conditional…

Minster, Sara Tepaeru; Jones, Max; Elliffe, Douglas; Muthukumaraswamy, Suresh D.

2006-01-01

156

Tests of the weak equivalence principle  

Microsoft Academic Search

The Einstein equivalence principle is the foundation for general relativity and all metric theories of gravity. Of its three tenets—the equality of acceleration of test bodies, or weak equivalence principle; the validity of Lorentz invariance in local freely falling frames; and the position invariance of local physical laws—the weak equivalence principle has played the most important role historically, and continues

C C Speake; C M Will

2012-01-01

157

Stimulus equivalence, generalization, and contextual stimulus control in verbal classes.  

PubMed

Stimulus generalization and contextual control affect the development of equivalence classes. Experiment 1 demonstrated primary stimulus generalization from the members of trained equivalence classes. Adults were taught to match six spoken Icelandic nouns and corresponding printed words and pictures to one another in computerized three-choice matching-to-sample tasks. Tests confirmed that six equivalence classes had formed. Without further training, plural forms of the stimuli were presented in tests for all matching performances. All participants demonstrated virtually errorless performances. In Experiment 2, classifications of the nouns used in Experiment 1 were brought under contextual control. Three nouns were feminine and three were masculine. The match-to-sample training taught participants to select a comparison of the same number as the sample (i.e., singular or plural) in the presence of contextual stimulus A regardless of noun gender. Concurrently, in the presence of contextual stimulus B, participants were taught to select a comparison of the same gender as the sample (i.e., feminine or masculine), regardless of number. Generalization was assessed using a card-sorting test. All participants eventually sorted the cards correctly into gender and number stimulus classes. When printed words used in training were replaced by their picture equivalents, participants demonstrated almost errorless performances. PMID:22754102

Sigurðardóttir, Zuilma Gabriela; Mackay, Harry A; Green, Gina

2012-01-01

158

Avoiding Liquidity Traps  

Microsoft Academic Search

Once the zero bound on nominal interest rates is taken into account, Taylor-type interest-rate feedback rules give rise to unintended self-fulfilling decelerating inflation paths and aggregate fluctuations driven by arbitrary revisions in expectations. These undesirable equilibria exhibit the essential features of liquidity traps, as monetary policy is ineffective in bringing about the government's goals regarding the stability of output and

Jess Benhabib; Stephanie Schmitt-Grohe; Mart ´ in Uribe

2000-01-01

159

The JPL trapped mercury ion frequency standard  

NASA Technical Reports Server (NTRS)

In order to provide frequency standards for the Deep Space Network (DSN) which are more stable than present-day hydrogen masers, a research task was established under the Advanced Systems Program of the TDA to develop a Hg-199(+) trapped ion frequency standard. The first closed-loop operation of this kind is described. Mercury-199 ions are confined in an RF trap and are state-selected through the use of optical pumping with 194 nm UV light from a Hg-202 discharge lamp. Absorption of microwave radiation at the hyperfine frequency (40.5 GHz) is signaled by atomic fluorescence of the UV light. The frequency of a 40.5 GHz oscillator is locked to a 1.6 Hz wide atomic absorption line of the trapped ions. The measured Allan variance of this locked oscillator is currently gamma sub y (pi) = 4.4 x 10 to the minus 12th/square root of pi for 20 is less than pi is less than 320 seconds, which is better stability than the best commercial cesium standards by almost a factor of 2. This initial result was achieved without magnetic shielding and without regulation of ion number.

Prestage, J. D.; Dick, G. J.; Maleki, L.

1988-01-01

160

Transport quantum logic gates for trapped ions  

SciTech Connect

Many efforts are currently underway to build a device capable of large scale quantum information processing (QIP). Whereas QIP has been demonstrated for a few qubits in several systems, many technical difficulties must be overcome in order to construct a large-scale device. In one proposal for large-scale QIP, trapped ions are manipulated by precisely controlled light pulses and moved through and stored in multizone trap arrays. The technical overhead necessary to precisely control both the ion geometrical configurations and the laser interactions is demanding. Here we propose methods that significantly reduce the overhead on laser-beam control for performing single- and multiple-qubit operations on trapped ions. We show how a universal set of operations can be implemented by controlled transport of ions through stationary laser beams. At the same time, each laser beam can be used to perform many operations in parallel, potentially reducing the total laser power necessary to carry out QIP tasks. The overall setup necessary for implementing transport gates is simpler than for gates executed on stationary ions. We also suggest a transport-based two-qubit gate scheme utilizing microfabricated permanent magnets that can be executed without laser light.

Leibfried, D.; Knill, E.; Ospelkaus, C.; Wineland, D. J. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305 (United States)

2007-09-15

161

Equivalence between Bell inequalities and quantum minority games  

NASA Astrophysics Data System (ADS)

We show that, for a continuous set of entangled four-partite states, the task of maximizing the payoff in the symmetric-strategy four-player quantum Minority game is equivalent to maximizing the violation of a four-particle Bell inequality. We conclude the existence of direct correspondences between (i) the payoff rule and Bell inequalities, and (ii) the strategy and the choice of measured observables in evaluating these Bell inequalities. We also show that such a correspondence is unique to minority-like games.

Flitney, Adrian P.; Schlosshauer, Maximilian; Schmid, Christian; Laskowski, Wies?aw; Hollenberg, Lloyd C. L.

2009-01-01

162

EFFECT OF FILTER TEMPERATURE ON TRAPPING ZINC VAPOR  

SciTech Connect

To address the {sup 65}Zn contamination issue in the TEF, a multi-task experimental program was initiated. The first experimental task was completed and is reported in Ref. 1. The results of the second experimental task are reported here. This task examined the effect of filter temperature on trapping efficiency and deposit morphology. Based on the first experimental tasks that examined filter pore size and trapping efficiency, stainless steel filter media with a 20 {micro}m pore size was selected. A series of experiments using these filters was conducted during this second task to determine the effect of filter temperature on zinc vapor trapping efficiency, adhesion and morphology. The tests were conducted with the filters heated to 60, 120, and 200 C; the zinc source material was heated to 400 C for all the experiments to provide a consistent zinc source. The samples were evaluated for mass change, deposit adhesion and morphology. As expected from the physical vapor deposition literature, a difference in deposit morphology and appearance was observed between the three filter temperatures. The filter held at 60 C had the largest average mass gain while the 120 and 200 C filters exhibited similar but lower weight gains. The standard deviations were large and suggest that all three temperatures exhibited comparable gains. No zinc was detected on the backside surface of the filters indicating high efficiency for front and internal trapping. A zinc rich deposit was formed on the surface of the 60 C filter. Based on a simple tape adhesion test, the surface zinc was readily removed from the 60 C filter while less zinc deposit was removed from the 120 and 200 C filter samples. It is surmised that the higher temperatures enable the zinc to deposit within the filter media rather than on the surface. Based on the findings that all three statistically trapped the same quantity of zinc vapor and that the higher temperatures resulted in a more adherent/better trapped product, operating the filters at 120 to 200 C is recommended.

Korinko, P.

2011-03-25

163

Optical trapping of anisotropic nanocylinder  

NASA Astrophysics Data System (ADS)

The T-matrix method with the Vector Spherical Wave Function (VSWF) expansions represents some difficulties for computing optical scattering of anisotropic particles. As the divergence of the electric field is nonzero in the anisotropic medium and the VSWFs do not satisfy the anisotropic wave equations one questioned whether the VSWFs are still a suitable basis in the anisotropic medium. We made a systematic and careful review on the vector basis functions and the VSWFs. We found that a field vector in Euclidean space can be decomposed to triplet vectors {L, M, N}, which as non-coplanar. Especially, the vector L is designed to represent non-zero divergence component of the vector solution, so that the VSWF basis is sufficiently general to represent the solutions of the anisotropic wave equation. The mathematical proof can be that when the anisotropic wave equations is solved in the Fourier space, the solution is expanded in the basis of the plan waves with angular spectrum amplitude distributions. The plane waves constitute an orthogonal and complete set for the anisotropic solutions. Furthermore, the plane waves are expanded into the VSWF basis. These two-step expansions are equivalent to the one-step direct expansion of the anisotropic solution to the VSWF basis. We used direct VSWF expansion, along with the point-matching method in the T-matrix, and applied the boundary condition to the normal components displacement field in order to compute the stress and the related forces and torques and to show the mechanism of the optical trap of the anisotropic nano-cylinders.

Bareil, Paul B.; Sheng, Yunlong

2013-09-01

164

It Pays to Be Organized: Organizing Arithmetic Practice around Equivalent Values Facilitates Understanding of Math Equivalence  

ERIC Educational Resources Information Center

This experiment tested the hypothesis that organizing arithmetic fact practice by equivalent values facilitates children's understanding of math equivalence. Children (M age = 8 years 6 months, N = 104) were randomly assigned to 1 of 3 practice conditions: (a) equivalent values, in which problems were grouped by equivalent sums (e.g., 3 + 4 = 7, 2…

McNeil, Nicole M.; Chesney, Dana L.; Matthews, Percival G.; Fyfe, Emily R.; Petersen, Lori A.; Dunwiddie, April E.; Wheeler, Mary C.

2012-01-01

165

Atom trapping in an interferometrically generated bottle beam trap.  

PubMed

We demonstrate an optical bottle beam trap created by interfering two fundamental Gaussian beams with different waists. The beams are derived from a single laser source using a Mach-Zehnder interferometer whose arms have unequal magnifications. Destructive interference of the two beams from the Mach-Zehnder leads to a three-dimensional intensity null at the mutual focus of the beams. We demonstrate trapping of cold cesium atoms in a blue detuned bottle beam trap. PMID:19370103

Isenhower, L; Williams, W; Dally, A; Saffman, M

2009-04-15

166

Modelling of optical trapping  

NASA Astrophysics Data System (ADS)

After more than thirty years after Arthur Ashkin's pioneering experiments the optical trapping is a widely established technique of the modern science. Its applications cover wide range of physics, chemistry and biology. In many of these applications the irregular, inhomogeneous or ensembles of many particles are exposed to the light fields where such particles could be stably confined. In this paper we will present results of several numerical methods that describe optical forces acting on particles placed in the non-diffracting Bessel Beam.

Šiler, Martin; Karásek, Vít?zslav; Brzobohatý, Oto; ?ižmár, Tomáš; Zemánek, Pavel

2011-06-01

167

Atom trap trace analysis  

SciTech Connect

A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O'Connor, T. P.; Young, L.

2000-05-25

168

Coronal particle trapping revisited  

NASA Astrophysics Data System (ADS)

We re-examine the idea of long-term particle storage in the solar corona in the context of modern PFSS (potential-field source surface) magnetic models. As pointed out by H. Elliot in 1964 and others since then, such particles could be energetically important, at the level of some large fraction of the magnetic energy density B2/8?. We estimate the distribution and time scales of particle trapping by using representative PFSS coronal models from the Schrijver-De Rosa SolarSoft code. As the coronal field simplifies during solar minimum, it approaches axisymmetry and thus contains volumes inaccessible to charged particles under the guiding-center approximation. We conclude that time scales can be sufficiently long, so long in fact that the azimuthal drift time scale (third adiabatic invariant of guiding-center motion), for the large-scale dipolar configuration characteristic of solar minimum, can exceed one solar cycle. We discuss the possible sources of trapped particles, starting with the basic CRAND (cosmic-ray albedo neutron decay) mechanism, and relate their X-ray and ?-ray signatures to future observational capabilities including the Sentinels spacecraft.

Hudson, H. S.; MacKinnon, A.; De Rosa, M.

2006-12-01

169

Build a Fruit Fly Trap  

NSDL National Science Digital Library

In this construction activity, students use a 2-liter bottle to build a fly trap. There is not much supporting information besides the directions, but the trap can be used to examine fly behavior, and it might also be redesigned by students. In the construction part of the activity, younger learners will need help and supervision from an older learner or adult, but any age learner can do independent observation of fly behavior once insects are inside the trap.

Wisconsin-Madison, Universitiy O.

2007-01-01

170

Task Communication in DEMOS  

Microsoft Academic Search

This paper describes the fundamentals and some of the details of task communication in DEMOS, the operating system for the CRAY-I computer being developed at the Los Alamos Scientific Laboratory. The communication mechan- ism is a message system with several novel features. Messages are sent from one task to another over links. Links are the primary protected objects in the

Forest Baskett; John H. Howard; John T. Montague

1977-01-01

171

On Change and Tasks  

Microsoft Academic Search

This paper observes that task analysis, despite its prominence in many HCI approaches, embodies a limited perspective on change sources and manifestations. The paper starts with a critique of the change management perspective of TA methods and illustrates the argument with two examples — Interacting Cognitive Subsystems, and Task Knowledge Structures. Following this, we examine some broader change sources, manifestations

Peter J Wild; Robert D Macredie

2000-01-01

172

Gated charged-particle trap  

DOEpatents

The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector.

Benner, W. Henry (Danville, CA)

1999-01-01

173

DNA Separation Using Photoelectrophoretic Traps  

SciTech Connect

In our recent publications we presented a design that allows formation of highly localized and optically controlled electrophoretic traps. 1,2 We demonstrated that electrophoretic traps can be utilized for biomolecule photoconcentration, optically directed transport, and separation by size. 1,2 In the current publication we suggest a hybrid design for biomolecule separation which implements electrophoretic traps in tandem with well-established electrophoretic techniques. We perform Monte Carlo simulations that demonstrate that the resolution of well-established electrophoretic techniques can be greatly enhanced by introducing photoelectrophoretic traps.

Braiman, Avital [ORNL; Thundat, Thomas George [ORNL; Rudakov, Fedor M [ORNL

2011-01-01

174

Optical traps with geometric aberrations  

SciTech Connect

We assess the influence of geometric aberrations on the in-plane performance of optical traps by studying the dynamics of trapped colloidal spheres in deliberately distorted holographic optical tweezers. The lateral stiffness of the traps turns out to be insensitive to moderate amounts of coma, astigmatism, and spherical aberration. Moreover holographic aberration correction enables us to compensate inherent shortcomings in the optical train, thereby adaptively improving its performance. We also demonstrate the effects of geometric aberrations on the intensity profiles of optical vortices, whose readily measured deformations suggest a method for rapidly estimating and correcting geometric aberrations in holographic trapping systems.

Roichman, Yael; Waldron, Alex; Gardel, Emily; Grier, David G

2006-05-20

175

Equivalent Conditions of Generalized Convex Fuzzy Mappings  

PubMed Central

We obtain some equivalent conditions of (strictly) pseudoconvex and quasiconvex fuzzy mappings. These results will be useful to present some characterizations of solutions for fuzzy mathematical programming.

Liu, Xue Wen; He, Dou

2014-01-01

176

Task Description Language  

NASA Technical Reports Server (NTRS)

Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

Simmons, Reid; Apfelbaum, David

2005-01-01

177

Timeline Resource Analysis Program (TRAP): User's manual and program document  

NASA Technical Reports Server (NTRS)

The Timeline Resource Analysis Program (TRAP), developed for scheduling and timelining problems, is described. Given an activity network, TRAP generates timeline plots, resource histograms, and tabular summaries of the network, schedules, and resource levels. It is written in ANSI FORTRAN for the Honeywell SIGMA 5 computer and operates in the interactive mode using the TEKTRONIX 4014-1 graphics terminal. The input network file may be a standard SIGMA 5 file or one generated using the Interactive Graphics Design System. The timeline plots can be displayed in two orderings: according to the sequence in which the tasks were read on input, and a waterfall sequence in which the tasks are ordered by start time. The input order is especially meaningful when the network consists of several interacting subnetworks. The waterfall sequence is helpful in assessing the project status at any point in time.

Sessler, J. G.

1981-01-01

178

Effects of a CARO on Stimulus Equivalence Formation: A Systematic Replication  

ERIC Educational Resources Information Center

In two experiments, we examined the disruptive effects of a "can't answer" response option (CARO) on equivalence formation. The first experiment was a systematic replication of Duarte, Eikeseth, Rosales-Ruiz, and Baer (1998), in which participants in a CARO group and a No-CARO group performed conditional discrimination tasks with abstract stimuli…

Imam, Abdulrazaq A.; Blanche, Justin V.

2013-01-01

179

A single trapped ion in a finite range trap  

SciTech Connect

Research Highlights: > We present a method to describe dynamics of an ion confined in a finite size trap. > The trap is modeled with a potential in the context of an f-deformed oscillator. > The ion exhibits nonclassical properties such as squeezing and quantum interference. > . > Also this system can be used to generate highly excited motional Fock state. > The Hilbert space size effects and nano traps can be investigated by this model. - Abstract: This paper presents a method to describe dynamics of an ion confined in a realistic finite range trap. We model this realistic potential with a solvable one and we obtain dynamical variables (raising and lowering operators) of this potential. We consider coherent interaction of this confined ion in a finite range trap and we show that its center-of-mass motion steady state is a special kind of nonlinear coherent states. Physical properties of this state and their dependence on the finite range of potential are studied.

Bagheri Harouni, M., E-mail: m-bagheri@phys.ui.ac.ir [Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81764-73441 (Iran, Islamic Republic of); Davoudi Darareh, M., E-mail: m.davoudi@sci.ui.ac.ir [Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81764-73441 (Iran, Islamic Republic of); Department of Physics, Malek-ashtar University of Technology, Shahin-shahr, P.O. Box 83145/115 (Iran, Islamic Republic of)

2011-04-15

180

Calibration of optical traps by dual trapping of one bead.  

PubMed

We introduce a method for optical trap calibration that is suitable for viscoelastic material. The method is designed for use on experimental setups with two optical tweezers and is based on pulling a trapped particle with one trap while holding it with the other. No piezo stage is needed, and only one optical trap must be movable with galvo mirrors, piezo mirrors, or acousto-optical deflectors. The method combines advantages of commonly known PSD-fitting and fast-sweeping methods, allowing calibration of a completely fixed trap in a fluid of unknown viscosity/viscoelasticity. A detailed method description, a theoretical derivation, and an experimental comparison to other methods are reported. PMID:24322167

Dutov, Pavel; Schieber, Jay

2013-11-15

181

Segmented trapped vortex cavity  

NASA Technical Reports Server (NTRS)

An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

2010-01-01

182

Thermal Replication Trap  

NASA Astrophysics Data System (ADS)

The hallmark of living matter is the replication of genetic molecules and their active storage against diffusion. We have argued in the past that thermal convection can host the million-fold accumulation even of single nucleotides and at the same time trigger exponential replication [1]. Accumulation is driven by thermophoresis and convection in elongated chambers, replication by the inherent temperature cycling in convection. Optothermal pumping [2,3] allows to implement the thermal trap efficiently in a toroidal [4] or linear [5] geometry. Based on this method, we were in a position to combine accumulation and replication of DNA in the same chamber [5]. As we are missing a solid chemistry of prebiotic replication, we used as a proxy reaction for to replication the polymerase chain reaction. Convective flow both drives the DNA replicating polymerase chain reaction (PCR) while concurrent thermophoresis accumulates the replicated 143 base pair DNA in bulk solution. The time constant for accumulation is 92 s while DNA is doubled every 50 s. The length of the amplified DNA is checked with thermophoresis. Finite element simulations confirm the findings. The experiments explore conditions in pores of hydrothermal rock which can serve as a model environment for the origin of life and has prospects towards the first autonomous evolution, hosting the Darwin process by molecular selection using the thermophoretic trap. On the other side, the implemented continuous evolution will be able to breed well specified DNA or RNA molecules in the future. [4pt] [1] Baaske, Weinert, Duhr, Lemke, Russell and Braun, PNAS 104, 9346 (2007) [0pt] [2] Weinert, Kraus, Franosch and Braun, PRL 100, 164501 (2008) [0pt] [3] Weinert and Braun, Journal of Applied Physics 104, 104701 (2008) [0pt] [4] Weinert and Braun, Nano Letters 9, 4264 (2009) [0pt] [5] Mast and Braun, PRL 104, 188102 (2010)

Braun, Dieter

2011-03-01

183

Equivalent Mass of a Coil Spring.  

ERIC Educational Resources Information Center

Finds that first-year college students can understand in detail the origin of the equivalent mass. Provides both a simple calculation derivation of this result as well as a noncalculus derivation. Argues that for every soft spring, the equivalent mass should be somewhere between m0/3 and m0/2. (CCM)

Ruby, Lawrence

2000-01-01

184

Replicating Ricardian Equivalence Tests with Simulated Series  

Microsoft Academic Search

This paper replicates standard consumption function tests of Ricardian equivalence using series generated from a model which nests Ricardian equivalence within a non-Ricardian alternative (due to finite horizons and\\/or distortionary taxation). The author shows that the estimates of the effects of taxation on consumption are not robust and that standard tests may have weaknesses which can lead to conflicting results,

Emanuela Cardia

1997-01-01

185

Tau-Equivalence and Equipercentile Equating.  

ERIC Educational Resources Information Center

Tau-equivalence means that two tests produce equal true scores for individuals but that the distribution of errors for the tests could be different. This paper examines the effect of performing equipercentile equating techniques on tau-equivalent tests. (JKS)

Yen, Wendy M.

1983-01-01

186

When are origin and destination regimes equivalent?  

Microsoft Academic Search

A series of equivalence results are established which show that a switch from a destination regime of commodity taxation to an origin regime has no real effects. These significantly generalize those in the existing literature. Assuming uniformity of taxes within each country, equivalence applies (1) in a general competitive economy with an arbitrary (finite) number of goods and factors of

Ben Lockwood; DAVID DE MEZA; Gareth D. Myles

1994-01-01

187

CMOS Equivalent Model of Ferroelectric RAM  

Microsoft Academic Search

The current research work in the paper is the representation of FRAM (Ferroelectric Random Access Memory) as an equivalent Model of Ferroelectric memory cell in Spice Tool. This Equivalent CMOS based model is designed to work at par with the behaviour working of the FRAM. The crux of the design of ferroelectric capacitor in the Ferroelectric Random Access Memory lies

Parvinder S. Sandhu; Iqbaldeep Kaur; Amit Verma; Birinderjit S. Kalyan; Jagdeep Kaur; Sanyam Anand

2010-01-01

188

Equivalency Programmes (EPs) for Promoting Lifelong Learning  

ERIC Educational Resources Information Center

Equivalency programmes (EPs) refers to alternative education programmes that are equivalent to the formal education system in terms of curriculum and certification, policy support mechanisms, mode of delivery, staff training, and other support activities such as monitoring, evaluation and assessment. The development of EPs is potentially an…

Haddad, Caroline, Ed.

2006-01-01

189

Receptor Response in Venus's Fly-Trap  

Microsoft Academic Search

The insect-trapping movement of the plant Dionaea muscipula (Venus's fly-trap) is mediated by the stimulation of mechanosensory hairs located on the surface of the trap. It is known that stimulation of the hairs is followed by action potentials which are propagated over the surface of the trap. It has been reported that action potentials always precede trap closure, The occurrence

STUART L. JACOBSON

1965-01-01

190

Trapping Single Molecules by Dielectrophoresis  

Microsoft Academic Search

We have trapped single protein molecules of R-phycoerythrin in an aqueous solution by an alternating electric field. A radio frequency voltage is applied to sharp nanoelectrodes and hence produces a strong electric field gradient. The resulting dielectrophoretic forces attract freely diffusing protein molecules. Trapping takes place at the electrode tips. Switching off the field immediately releases the molecules. The electric

Ralph Hölzel; Nils Calander; Zackary Chiragwandi; Magnus Willander; Frank F. Bier

2005-01-01

191

Injection into electron plasma traps  

SciTech Connect

Computational studies and experimental measurements of plasma injection into a Malmberg-Penning trap reveal that the number of trapped particles can be an order of magnitude higher than predicted by a simple estimates based on a ballistic trapping model. Enhanced trapping is associated with a rich nonlinear dynamics generated by the space-charge forces of the evolving trapped electron density. A particle-in-cell simulation is used to identify the physical mechanisms that lead to the increase in trapped electrons. The simulations initially show strong two-stream interactions between the electrons emitted from the cathode and those reflected off the end plug of the trap. This is followed by virtual cathode oscillations near the injection region. As electrons are trapped, the initially hollow longitudinal phase-space is filled, and the transverse radial density profile evolves so that the plasma potential matches that of the cathode. Simple theoretical arguments are given that describe the different dynamical regimes. Good agreement is found between simulation and theory.

Gorgadze, Vladimir; Pasquini, Thomas A.; Fajans, Joel; Wurtele, Jonathan S.

2003-12-02

192

Traps status in the industry  

Microsoft Academic Search

Generally, the condition of most steam systems is substandard, with identifiable steam trap failures exceeding 30%. This situation can be changed with an understanding of the purpose and function of the steam system. Steam traps are automatic control valves that open to permit the flow of condensate, yet close to prevent the flow of steam. They must be able to

1983-01-01

193

Thinking About the Liquidity Trap  

Microsoft Academic Search

The phenomenon of the liquidity trap—defined as a situation in which even a zero interest rate is insufficiently low to produce full employment—has taken on new importance with the persistent slump in Japan. This paper restates recent theoretical work on liquidity traps, drawing a link between “intertemporal” models that are mainly concerned with demonstrating the underlying logic, and more ad

Paul Krugman

2000-01-01

194

Quantum optics with trapped ions  

SciTech Connect

In these lecture notes, I describe the use of ion traps in experimental investigations of quantum optics. Ion traps are well suited to this type of investigation because of the well-controlled conditions under which ions are held in traps and because they are well isolated from the environment. The notes start with an account of the way that ion traps work, concentrating on the radiofrequency or Paul trap. The techniques of laser cooling in ion traps are then discussed. The rest of the notes deal with various experimental studies undertaken in quantum optics with trapped ions, including observations of quantum jumps: the quantum Zeno effect; cavity quantum electrodynamics; frequency standards; nonclassical states; and quantum logic gates. These notes do not attempt to give a full account of the theory of these phenomena, but rather to give an idea of the very wide range of investigations that have been undertaken with ion traps and the potential they show for future investigations in quantum optics and other fields.

Thompson, Richard [Blackett Laboratory, Imperial College, Prince Consort Rd., London SW7 2BZ (United Kingdom)

1999-03-06

195

Validation of the trapped charge model of electrowetting contact angle saturation on lipid bilayers  

NASA Astrophysics Data System (ADS)

The problem of modeling contact angle saturation in electrowetting has resisted a number of concentrated efforts by leading researchers. Several models have been proposed, from charge trapping, to droplet ejection, to thermodynamic instability, but no consensus has been reached as to which model better describes the effect. In this paper, we validate the charge trapping based model of contact angle saturation in electrowetting on lipid bilayers, through careful analysis of charge movement between the liquid charge states and trapped charge states at the solid dielectric interface. We also describe a powerful new methodology for studying electrowetting systems by modeling them with an equivalent circuit and simulating the circuit using the SPICE circuit simulator.

Kedzierski, Jakub T.; Batra, Richa; Berry, Shaun; Guha, Ingrid; Abedian, Behrouz

2013-07-01

196

Mid-gap trap states in CdTe nanoparticle solar cells  

NASA Astrophysics Data System (ADS)

Thin film solar cells comprised of quantum-confined CdTe nanoparticles are shown to have a low intrinsic density of mid-gap trap states relative to their equivalent bulk film, indicating that the ligands are effective at electrically passivating surface states. Sintering the nanoparticles into a poly-crystalline thin film increases device performance but also increases the density of mid-gap trap states due to doping from the CdCl treatment and the formation of long range disorder such as grain boundaries and dislocations. Long term aging under illumination increases the density of mid-gap traps in the unsintered films due to degradation of the ligands.

Bezryadina, A.; France, C.; Graham, R.; Yang, L.; Carter, S. A.; Alers, G. B.

2012-01-01

197

Single-Atom Trapping in Holographic 2D Arrays of Microtraps with Arbitrary Geometries  

NASA Astrophysics Data System (ADS)

We demonstrate single-atom trapping in two-dimensional arrays of microtraps with arbitrary geometries. We generate the arrays using a spatial light modulator, with which we imprint an appropriate phase pattern on an optical dipole-trap beam prior to focusing. We trap single Rb87 atoms in the sites of arrays containing up to approximately 100 microtraps separated by distances as small as 3 ?m, with complex structures such as triangular, honeycomb, or kagome lattices. Using a closed-loop optimization of the uniformity of the trap depths ensures that all trapping sites are equivalent. This versatile system opens appealing applications in quantum-information processing and quantum simulation, e.g., for simulating frustrated quantum magnetism using Rydberg atoms.

Nogrette, F.; Labuhn, H.; Ravets, S.; Barredo, D.; Béguin, L.; Vernier, A.; Lahaye, T.; Browaeys, A.

2014-04-01

198

Nanocarpets for Trapping Microscopic Particles  

NASA Technical Reports Server (NTRS)

Nanocarpets that is, carpets of carbon nanotubes are undergoing development as means of trapping microscopic particles for scientific analysis. Examples of such particles include inorganic particles, pollen, bacteria, and spores. Nanocarpets can be characterized as scaled-down versions of ordinary macroscopic floor carpets, which trap dust and other particulate matter, albeit not purposefully. Nanocarpets can also be characterized as mimicking both the structure and the particle-trapping behavior of ciliated lung epithelia, the carbon nanotubes being analogous to cilia. Carbon nanotubes can easily be chemically functionalized for selective trapping of specific particles of interest. One could, alternatively, use such other three-dimensionally-structured materials as aerogels and activated carbon for the purposeful trapping of microscopic particles. However, nanocarpets offer important advantages over these alternative materials: (1) Nanocarpets are amenable to nonintrusive probing by optical means; and (2) Nanocarpets offer greater surface-to-volume ratios.

Noca, Flavio; Chen, Fei; Hunt, Brian; Bronikowski, Michael; Hoenk, Michael; Kowalczyk, Robert; Choi, Daniel

2004-01-01

199

4.NF Explaining Fraction Equivalence with Pictures  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The rectangle below has length 1. What fraction does the shaded part represent? The rectangle below has the same length as the rectangle above. What fr...

200

Fuel Hedging Task Group.  

National Technical Information Service (NTIS)

At the direction of the Under Secretary of Defense (Comptroller) (USD (C)), the Defense Business Board (formerly known as the Defense Business Practice Implementation Board) was tasked with examining potential ways to reduce the Department's exposure to f...

2004-01-01

201

Globalization Task Force Report.  

National Technical Information Service (NTIS)

Since the last meeting of the President's National Security Telecommunications Advisory Committee (NSTAC) in June 1999, the Globalization Task Force (GTF)1 has concentrated its efforts on national security and emergency preparedness (NS/EP) issues related...

2000-01-01

202

Task-Ambient Lighting.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. Overall visibility at individual work stations can be significantly improved while actually saving energy by using task-ambient lighting rather than uniform office l...

1982-01-01

203

TecTask  

NSDL National Science Digital Library

The Task Group on Tectonics and Structural Geology (TecTask) is a committee of the IUGS that represents an initiative of earth scientists dedicated to stimulating communication and coordination within the international science community and to providing information to the public. The site features links to conferences, data, and downloadable software, as well as journals, organizations and societies dedicated to various aspects of structural geology.

The Task Group on Tectonics and Structural Geology (TecTask); Tectask

204

Equivalence-Equivalence Responding: Training Conditions Involved in Obtaining a Stable Baseline Performance  

ERIC Educational Resources Information Center

Recent research has focused on the variables associated with equivalence-equivalence responding, in which participants match pairs of equivalent or nonequivalent stimuli. One such variable is the presence of response competition from nonarbitrary (physical) relational response options. In the current analysis, the experimenters examined the effect…

Garcia, Andres; Bohorquez, Cristobal; Perez, Vicente; Gutierrez, Maria Teresa; Gomez, Jesus; Luciano, Carmen; Wilson, Kelly

2008-01-01

205

Charge Trapping in Interface Doped MNOS Structures.  

National Technical Information Service (NTIS)

Evaporated tungsten interface dopant, oxide-nitride interface and nitride bulk traps in MNOS structures were examined using charge centroid and thermally stimulated current (TSC) techniques. Trapping in dopant traps occurred at low injected charge levels....

W. G. Sutton

1981-01-01

206

The trapped human experiment.  

PubMed

This experiment observed the evolution of metabolite plumes from a human trapped in a simulation of a collapsed building. Ten participants took it in turns over five days to lie in a simulation of a collapsed building and eight of them completed the 6 h protocol while their breath, sweat and skin metabolites were passed through a simulation of a collapsed glass-clad reinforced-concrete building. Safety, welfare and environmental parameters were monitored continuously, and active adsorbent sampling for thermal desorption GC-MS, on-line and embedded CO, CO(2) and O(2) monitoring, aspirating ion mobility spectrometry with integrated semiconductor gas sensors, direct injection GC-ion mobility spectrometry, active sampling thermal desorption GC-differential mobility spectrometry and a prototype remote early detection system for survivor location were used to monitor the evolution of the metabolite plumes that were generated. Oxygen levels within the void simulator were allowed to fall no lower than 19.1% (v). Concurrent levels of carbon dioxide built up to an average level of 1.6% (v) in the breathing zone of the participants. Temperature, humidity, carbon dioxide levels and the physiological measurements were consistent with a reproducible methodology that enabled the metabolite plumes to be sampled and characterized from the different parts of the experiment. Welfare and safety data were satisfactory with pulse rates, blood pressures and oxygenation, all within levels consistent with healthy adults. Up to 12 in-test welfare assessments per participant and a six-week follow-up Stanford Acute Stress Response Questionnaire indicated that the researchers and participants did not experience any adverse effects from their involvement in the study. Preliminary observations confirmed that CO(2), NH(3) and acetone were effective markers for trapped humans, although interactions with water absorbed in building debris needed further study. An unexpected observation from the NH(3) channel was the suppression of NH(3) during those periods when the participants slept, and this will be the subject of further study, as will be the detailed analysis of the casualty detection data obtained from the seven instruments used. PMID:21908906

Huo, R; Agapiou, A; Bocos-Bintintan, V; Brown, L J; Burns, C; Creaser, C S; Devenport, N A; Gao-Lau, B; Guallar-Hoyas, C; Hildebrand, L; Malkar, A; Martin, H J; Moll, V H; Patel, P; Ratiu, A; Reynolds, J C; Sielemann, S; Slodzynski, R; Statheropoulos, M; Turner, M A; Vautz, W; Wright, V E; Thomas, C L P

2011-12-01

207

Equivalent circuit for broadband underwater transducers.  

PubMed

A method is presented to determine the equivalent circuits of broadband transducers with 2 resonances in the frequency band of interest. The circuit parameters are refined by least-squares fitting the measured electrical conductance data with this model. The method is illustrated by computing the conductance and susceptance of the equivalent circuits of 3 types of broadband transducers and comparing them with the measured values. The equivalent circuit of a transducer is necessary for designing filters that match the impedances of the transducer and the power amplifier that drives the transducer. PMID:18986904

Ramesh, R; Ebenezer, D D

2008-09-01

208

First Attempts at Antihydrogen Trapping in ALPHA  

SciTech Connect

The ALPHA apparatus is designed to produce and trap antihydrogen atoms. The device comprises a multifunction Penning trap and a superconducting, neutral atom trap having a minimum-B configuration. The atom trap features an octupole magnet for transverse confinement and solenoidal mirror coils for longitudinal confinement. The magnetic trap employs a fast shutdown system to maximize the probability of detecting the annihilation of released antihydrogen. In this article we describe the first attempts to observe antihydrogen trapping.

Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S. [Department of Physics, University of California at Berkeley, Berkeley, CA 94720-7300 (United States); Cesar, C. L.; Lambo, R.; Silveira, D. M. [Instituto de Fisica Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Fujiwara, M. C. [TRIUMF, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3 (Canada)] (and others)

2008-08-08

209

Backward Blocking and Interference between Cues Are Empirically Equivalent in Non-Causally Framed Learning Tasks  

ERIC Educational Resources Information Center

Backward blocking (BB) and interference between cues (IbC) are cue competition effects produced by very similar manipulations. In a standard BB design, both effects might occur simultaneously, which implies a potential problem for studying BB. In the present study with humans, the magnitude of both effects was compared using a non-causal scenario…

Luque, David; Moris, Joaquin; Orgaz, Cristina; Cobos, Pedro L.; Matute, Helena

2011-01-01

210

Combined acoustic and optical trapping  

PubMed Central

Combining several methods for contact free micro-manipulation of small particles such as cells or micro-organisms provides the advantages of each method in a single setup. Optical tweezers, which employ focused laser beams, offer very precise and selective handling of single particles. On the other hand, acoustic trapping with wavelengths of about 1 mm allows the simultaneous trapping of many, comparatively large particles. With conventional approaches it is difficult to fully employ the strengths of each method due to the different experimental requirements. Here we present the combined optical and acoustic trapping of motile micro-organisms in a microfluidic environment, utilizing optical macro-tweezers, which offer a large field of view and working distance of several millimeters and therefore match the typical range of acoustic trapping. We characterize the acoustic trapping forces with the help of optically trapped particles and present several applications of the combined optical and acoustic trapping, such as manipulation of large (75 ?m) particles and active particle sorting.

Thalhammer, G.; Steiger, R.; Meinschad, M.; Hill, M.; Bernet, S.; Ritsch-Marte, M.

2011-01-01

211

A comparison of adult mosquito trapping regimes across seasons and ecosystems in Darwin, Australia.  

PubMed

Mosquitoes are problematic as vectors and pests in many tropical cities, including Darwin, the principal city in the Northern Territory of Australia. To monitor peaks in mosquito populations, the Medical Entomology unit of the Health Department sets overnight CO(2) -baited traps weekly. Trap setting and retrieving, followed by mosquito counting and identification, are labor intensive. Aiming to reduce this workload, we tested the hypothesis that fortnightly trapping is as effective as weekly trapping across seasons and ecologically distinct systems in Darwin. We applied cross-sectional negative binomial mixed effects models, which adjusted for rain and calendar month, to existing historical data. Culex annulirostris peaks were effectively identified using fortnightly trapping across all three ecological systems, during wet/dry and build-up seasonal patterns. For Aedes vigilax, fortnightly trapping was adequate in identifying peaks during wet and dry season months, but inadequate during build-up months across all three ecological systems. Therefore, weekly trapping should continue during build-up months, but trapping could be reduced to fortnightly for wet and dry season months for all ecological systems. Trapping for Cx. annulirostris monitoring could be reduced to fortnightly in all areas and seasons. Evaluation of programs can maximize staff efficiency and improve service delivery by reducing the need for unnecessary tasks. PMID:23181850

Jacups, Susan P; Whelan, Peter I

2012-12-01

212

Trapped rossby waves  

PubMed

The possibility of tidal dynamics at strictly imaginary Lamb parameters has been known for more than three decades. The present paper explores the prevailing physics in this parameter regime. To this end, basic features of the global circulation such as baroclinicity and geostrophy have to be incorporated into tidal dynamics. The tidal equations of the thermal wind are readily obtained in the framework of spherical bishallow water theory. Density surfaces of a circulation with available potential energy alter the spatial inhomogenities of the generic tidal problem. Wave dynamics in an inhomogeneous medium are characterized not only by a dispersion relation but also by a wave guide geography: significant wave amplitudes are trapped in specific regions of frequency-dependent width. As an inherently global issue, evaluation of the Rossby wave guide geography for a given circulation cannot rely on the familiar regional filters of tidal theory. On the global domain, the Rossby wave specification is given by the Margules filter. A thermal wind is stable against nondivergent Rossby wave disturbances. Rossby waves propagating with a geostrophic wind are governed by prolate dynamics (real Lamb parameters) while imaginary Lamb parameters emerge for the oblate dynamics of Rossby waves running against a geostrophic wind. Oblate Rossby wave dynamics include pole-centered wave guides and very low-frequency disturbances propagating eastward against a westward wind. PMID:11046427

Muller

2000-02-01

213

The Economist Interactive: Equivalent Country Comparisons  

NSDL National Science Digital Library

This interactive tools allows the user to learn which countries parallel the states, provinces or territories of the United States, China, India and Brazil and  presents country equivalent data for both GDP and population.

214

A Supplementary Strategy for Teaching Equivalent Fractions.  

ERIC Educational Resources Information Center

Describes a supplementary method for teaching equivalent fractions through the use of a multiplication matrix, providing a simple visual and concrete activity that aids learners in understanding this difficult concept. (SR)

Coker, Donald R.; Cook, Donni Chandler

1992-01-01

215

Undecidable Equivalences for Basic Process Algebra.  

National Technical Information Service (NTIS)

A recent theorem shows that strong bisimilarity is decidable for the class of 'normed' BPA (Basic Process Algebra) processes, which correspond to context free grammars. Huynh and Tian showed that readiness and failure equivalence are undecidable for BPA p...

J. F. Groote H. Huettel

1991-01-01

216

Task-specific Dystonias  

PubMed Central

Task-specific dystonias are primary focal dystonias characterized by excessive muscle contractions producing abnormal postures during selective motor activities that often involve highly skilled, repetitive movements. Historically these peculiar postures were considered psychogenic but have now been classified as forms of dystonia. Writer’s cramp is the most commonly identified task-specific dystonia and has features typical of this group of disorders. Symptoms may begin with lack of dexterity during performance of a specific motor task with increasingly abnormal posturing of the involved body part as motor activity continues. Initially, the dystonia may manifest only during the performance of the inciting task, but as the condition progresses it may also occur during other activities or even at rest. Neurological exam is usually unremarkable except for the dystonia-related abnormalities. Although the precise pathophysiology remains unclear, increasing evidence suggests reduced inhibition at different levels of the sensorimotor system. Symptomatic treatment options include oral medications, botulinum toxin injections, neurosurgical procedures, and adaptive strategies. Prognosis may vary depending upon body part involved and specific type of task affected. Further research may reveal new insights into the etiology, pathophysiology, natural history, and improved treatment of these conditions.

Torres-Russotto, Diego; Perlmutter, Joel S.

2009-01-01

217

The Nonequivalence of High School Equivalents  

Microsoft Academic Search

This article analyzes the causes and consequences of the growing proportion of high-school-certified persons who achieve that status by exam certification rather than through high school graduation. Exam-certified high school equivalents are statistically indistinguishable from high school dropouts. Whatever differences are found among exam-certified equivalents, high school dropouts and high school graduates are accounted for by their years of schooling

Stephen V. Cameron; James J. Heckman

1993-01-01

218

Arthroscopic Transosseous-Equivalent Rotator Cuff Repair  

PubMed Central

Rotator cuff repair techniques continue to evolve in an effort to improve repair biomechanics, maximize the biologic environment for tendon healing, and ultimately improve patient outcomes. The arthroscopic transosseous-equivalent technique was developed to replicate the favorable tendon-bone contact area for healing seen in open transosseous tunnel repair. In this technical note and accompanying video, we present our all-arthroscopic transosseous-equivalent rotator cuff repair technique with a focus on technical pearls.

Lavery, Kyle P.; Rasmussen, Jeffrey F.; Dhawan, Aman

2013-01-01

219

Dark matter and the equivalence principle  

NASA Technical Reports Server (NTRS)

A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

Frieman, Joshua A.; Gradwohl, Ben-Ami

1993-01-01

220

Multilingual energy dictionary. [Equivalents in 6 languages  

SciTech Connect

This dictionary covers 1600 entries - ranging from oil well to synthetic natural gas and waste heat recovery - that cover both concepts and equipment, providing the equivalents of the most-important energy terms in six languages: English, French, German, Italian, Portuguese, and Spanish. Each term is listed six times - under each language, with all five foreign equivalents - permitting easy translation among all six languages. Separate entries are also given for British and American English where usage differs in the two countries.

Isaacs, A. (ed.)

1981-01-01

221

Method for the prediction of the effective dose equivalent to the crew of the International Space Station  

NASA Astrophysics Data System (ADS)

This paper describes a methodology for assessing the pre-mission exposure of space crew aboard the International Space Station (ISS) in terms of an effective dose equivalent. In this approach, the PHITS Monte Carlo code was used to assess the particle transport of galactic cosmic radiation (GCR) and trapped radiation for solar maximum and minimum conditions through an aluminum shield thickness. From these predicted spectra, and using fluence-to-dose conversion factors, a scaling ratio of the effective dose equivalent rate to the ICRU ambient dose equivalent rate at a 10 mm depth was determined. Only contributions from secondary neutrons, protons, and alpha particles were considered in this analysis. Measurements made with a tissue equivalent proportional counter (TEPC) located at Service Module panel 327, as captured through a semi-empirical correlation in the ISSCREM code, where then scaled using this conversion factor for prediction of the effective dose equivalent. This analysis shows that at this location within the service module, the total effective dose equivalent is 10-30% less than the total TEPC dose equivalent. Approximately 75-85% of the effective dose equivalent is derived from the GCR. This methodology provides an opportunity for pre-flight predictions of the effective dose equivalent and therefore offers a means to assess the health risks of radiation exposure on ISS flight crew.

El-Jaby, Samy; Tomi, Leena; Sihver, Lembit; Sato, Tatsuhiko; Richardson, Richard B.; Lewis, Brent J.

2014-03-01

222

Equivalent Circuits as Related to Ionic Systems  

PubMed Central

The purpose of this paper is to clarify the relationship between certain “equivalent circuits” and the fundamental flux equations of Nernst and Planck. It is shown that as a direct algebraic consequence of these equations one may construct two types of equivalent circuits for a homogeneous (charged or uncharged) membrane. The one, which we term the “pure electrical equivalent circuit,” correctly predicts all of the electrical properties of the membrane for both steady and transient states. The other, which we call the “mixed equivalent circuit,” predicts the steady state I, ? characteristics of the membrane and the steady state ionic fluxes; it is not applicable to non-steady state properties or measurements. We emphasize that with regard to the portrayal of the physical basis of the properties of a homogeneous membrane, the mixed equivalent circuit can be misleading. This is particularly significant because this same circuit can also be used to depict a mosaic membrane, in which case the circuit gives a realistic pictorialization of the physical origin of the membrane properties. It is hoped that our analysis will be of aid to workers in electrophysiology who make use of equivalent circuit terminology in discussing the behavior of the plasma membrane.

Finkelstein, Alan; Mauro, Alexander

1963-01-01

223

Mini ion trap mass spectrometer  

DOEpatents

An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

Dietrich, D.D.; Keville, R.F.

1995-09-19

224

Mini ion trap mass spectrometer  

DOEpatents

An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

1995-01-01

225

Gated charged-particle trap  

DOEpatents

The design and operation of a new type of charged-particle trap provides simultaneous measurements of mass, charge, and velocity of large electrospray ions. The trap consists of a detector tube mounted between two sets of center-bored trapping plates. Voltages applied to the trapping plates define symmetrically-opposing potential valleys which guide axially-injected ions to cycle back and forth through the charge-detection tube. A low noise charge-sensitive amplifier, connected to the tube, reproduces the image charge of individual ions as they pass through the detector tube. Ion mass is calculated from measurement of ion charge and velocity following each passage through the detector. 5 figs.

Benner, W.H.

1999-03-09

226

Zonal Dynamic Equivalents Based on the Concept of Relative Electrical Distance  

NASA Astrophysics Data System (ADS)

Abstract: This article presents a systematic approach to construct the zonal dynamic equivalents of a large-power system based on the concept of relative electrical distance (RED). The task of dynamic equivalencing is to eliminate the full model of the external system and replace it with an equivalent model, which has dynamic characteristics close enough to the full model. The dynamic equivalent models are used for large-scale power system offline transient stability analysis with large disturbance. Dynamic equivalencing also helps in reducing the computation burden and memory requirements in wide area monitoring system (WAMS) for online stability assessment. The procedure is illustrated on IEEE 39 bus system and on a practical 205 bus system consisting of three zones of Indian Southern grid, where an equivalent of a zone has been constructed. The simulation results of the original system and equivalent system are compared. The proposed approach is also compared with the existing Ward equivalent method and the results are found to be similar. The simulation results show that the developed equivalent system has close accuracy in representing the dynamic characteristics of the original system.

Agrawal, Rimjhim; Dhadbanjan, Thukaram

2013-05-01

227

Quantification of the Nonenzymatic Fast and Slow TRAP in a Postaddition Assay in Human Seminal Plasma and the Antioxidant Contributions of Various Seminal Compounds  

Microsoft Academic Search

Total radical-trapping antioxidant potential (TRAP) measurements of human seminal plasma (N 25) were performed by using a post-addition assay based on trapping 2,2 Azino-bis(3- ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals. This method enables the antioxidant capacity of human seminal plasma and its constituents to be quantified. The standard procedure consisted of determination of the Trolox equivalent antioxidant capacity (TEAC) after incubating the

JOHANN P. T. RHEMREV; FLORIS W. P. C. VAN OVERVELD; GUIDO R. M. M. HAENEN; TOM TEERLINK; AALT BAST; JAN P. W. VERMEIDEN

228

Generation of coastally trapped waves and secondary cyclones by an eddy approaching shelf topography  

Microsoft Academic Search

We consider the evolution of an isolated anticyclonic vortex encountering a continental shelf during its westward -drift in the framework of an equivalent- barotropic model generalized to allow for the intersection of the layer interface with a sloping bottom. The approaching vortex generates both topographic coastally trapped waves, and secondary cyclonic eddies due to o-shelf advection of water with high

Georgi G. Sutyrin

229

Nanofriction in Cold Ion Traps  

NASA Astrophysics Data System (ADS)

Sliding friction between crystal lattices and the physics of cold ion traps are so far non-overlapping fields. Two sliding lattices may either stick and show static friction or slip with dynamic friction; cold ions are known to form static chains, helices, or clusters, depending on trapping conditions. Based on simulations, we show that much could be learnt about friction by sliding (e.g., via an electric field) the trapped ion chains over a periodic corrugated potential. Unlike infinite chains where, according to theory, the classic Aubry transition to free sliding may take place, static pinning always shows up in trapped chains. Nonetheless we find that a properly defined static friction still vanishes Aubry-like at a symmetric-asymmetric structural transition, ubiquitous for decreasing corrugation in both straight and zig-zag trapped chains. Dynamic friction can also be addressed by ringdown oscillations of the ion trap. Long theorized static and dynamic one dimensional friction phenomena could thus become exquisitely accessible in future cold ion tribology.

Vanossi, Andrea; Benassi, Andrea; Tosatti, Erio

2011-03-01

230

Exogenous influences on task set activation in task switching  

Microsoft Academic Search

To explore the effect of exogenous processes on cognitive control, we used a cueing task-switching paradigm with two spatial judgement tasks and added an irrelevant colour attribute to the task-relevant spatial attribute of the target. The colour was not related to any specific Stimulus–Response relation in the tasks. A correlation was created between stimulus colour and task identity. This correlation

Orit Rubin; Iring Koch

2006-01-01

231

Interstitial trapped hydrogen molecules in PECVD amorphous silicon  

SciTech Connect

New NMR measurements show that interstitial T site-trapped molecular hydrogen can amount to more than one third of the contained hydrogen in high quality PECVD amorphous silicon. Microvoid-contained dense molecular hydrogen is negligible in these good films. Experiments on a sequence of hydrogenated and/or deuterated a-Si films have characterized individually-trapped molecular HD and D{sub 2} in films deposited from SiD{sub 4}, and from SiH{sub 4}+D{sub 2}. The T site-trapped molecular hydrogen fraction observed here is larger than previously reported because of recent efforts to measure very slowly relaxing molecular components and the employment of radiofrequency pulse sequences to detect ortho-D{sub 2} with nuclear spin I = 2. The population of interstitially trapped molecular hydrogen increases with increasing photovoltaic quality over a range of an order of magnitude in photoresponse product {eta}{mu}{tau}. Above 200 K, hopping transport of molecular hydrogen among the amorphous equivalent of interstitial T sites occurs with an activation energy near 50 meV.

Borzi, R.; Mascarenhas, F.; Fedders, P.A.; Leopold, D.J.; Norberg, R.E.; Wickboldt, P.; Paul, W.

1999-07-01

232

Ultra-thin, light-trapping silicon solar cells  

NASA Technical Reports Server (NTRS)

Design concepts for ultra-thin (2 to 10 microns) high efficiency single-crystal silicon cells are discussed. Light trapping allows more light to be absorbed at a given thickness, or allows thinner cells of a given Jsc. Extremely thin cells require low surface recombination velocity at both surfaces, including the ohmic contacts. Reduction of surface recombination by growth of heterojunctions of ZnS and GaP on Si has been demonstrated. The effects of these improvements on AM0 efficiency is shown. The peak efficiency increases, and the optimum thickness decreases. Cells under 10 microns thickness can retain almost optimum power. The increase of absorptance due to light trapping is considered. This is not a problem if the light-trapping cells are sufficiently thin. Ultra-thin cells have high radiation tolerance. A 2 microns thick light-trapping cell remains over 18 percent efficient after the equivalent of 20 years in geosynchronous orbit. Including a 50 microns thick coverglass, the thin cells had specific power after irradiation over ten times higher than the baseline design.

Landis, Geoffrey A.

1989-01-01

233

Acquired equivalence and generalized suppression in a virtual reality environment.  

PubMed

Acquired equivalence was investigated using a virtual reality conditioned suppression task administered in a first-person-shooter game. Two visual cues, A1 and B1, were followed by a tone (O1), and another two cues, A2 and B2, were followed by another tone (O2). During differential Pavlovian conditioning, A1 was paired with an instructed unconditioned stimulus (US) consisting of a flashing white screen, whereas A2 was not. All cues and outcomes were then presented at test, in the absence of the US, and suppression ratios were calculated for multiple response topographies (shots, hits, and breaks). Clear evidence of the suppression of shots was seen for A1 and B1, with no suppression being seen for either A2 or B2. Presentations of O1 and O2 resulted in significant suppression of shots and hits, whereas only O1 led to the suppression of breaks. The US expectancy ratings were consistent with these behavioral results. The findings are discussed in the light of differing accounts of acquired equivalence. PMID:24366672

Greville, W James; Dymond, Simon; Newton, Philip M; Roche, Bryan

2014-06-01

234

An Analysis of Synchrony between Concrete-operational Tasks in Terms of Structural and Performance Demands  

ERIC Educational Resources Information Center

A set of tasks theoretically presumed to require equivalent logical competence (multiplication of classes, multiplication of relations, seriation, and transitivity) was administered to 64 first and second graders. Response measures emphasizing the operative and figurative aspects were compared within each task. (Author/SDH)

Toussaint, N. A.

1974-01-01

235

Planetary image conversion task  

NASA Technical Reports Server (NTRS)

The Planetary Image Conversion Task group processed 12,500 magnetic tapes containing raw imaging data from JPL planetary missions and produced an image data base in consistent format on 1200 fully packed 6250-bpi tapes. The output tapes will remain at JPL. A copy of the entire tape set was delivered to US Geological Survey, Flagstaff, Ariz. A secondary task converted computer datalogs, which had been stored in project specific MARK IV File Management System data types and structures, to flat-file, text format that is processable on any modern computer system. The conversion processing took place at JPL's Image Processing Laboratory on an IBM 370-158 with existing software modified slightly to meet the needs of the conversion task. More than 99% of the original digital image data was successfully recovered by the conversion task. However, processing data tapes recorded before 1975 was destructive. This discovery is of critical importance to facilities responsible for maintaining digital archives since normal periodic random sampling techniques would be unlikely to detect this phenomenon, and entire data sets could be wiped out in the act of generating seemingly positive sampling results. Reccomended follow-on activities are also included.

Martin, M. D.; Stanley, C. L.; Laughlin, G.

1985-01-01

236

Job Task Analysis.  

ERIC Educational Resources Information Center

This publication consists of job task analyses for jobs in textile manufacturing. Information provided for each job in the greige and finishing plants includes job title, job purpose, and job duties with related educational objectives, curriculum, assessment, and outcome. These job titles are included: yarn manufacturing head overhauler, yarn…

Clemson Univ., SC.

237

The Task Matrix Procedure.  

National Technical Information Service (NTIS)

A method for developing work samples geared to a range of entry-level jobs in an occupation or industry, rather than to a specific job, was developed in 1975. Differences between the task matrix procedure and conventional work sample development are discu...

T. A. Korn D. J. Dunn

1975-01-01

238

Microinteractions beside ongoing manual tasks  

Microsoft Academic Search

This paper explores how microinteractions as finger gestures allow executing a secondary task without interrupting the manual primary tasks such as driving a car or using a smart stylus. An analyses of Bock's Grip Taxonomy helps to identify manual primary tasks that have a huge benefit of not being interrupted by secondary tasks to control mobile applications and devices. This

Katrin Wolf

2011-01-01

239

All steam traps aren`t equal  

Microsoft Academic Search

Steam traps are automatic valves that sense the difference between steam, air, condensate, and noncondensate gases such as COâ. Their objective is to purge air, condensate, and other noncondensate gases and trap steam in the system where it belongs. A properly working trap should never let steam escape. Though the requirements for steam traps are simple, even the most experienced

Picut

1996-01-01

240

All steam traps are not equal  

Microsoft Academic Search

Proper selection of a steam trap will result in a long-lasting, trouble-free steam distribution system. The definition of a trap is simple enough: it should get rid of air and purge off noncondensibles when the system is started up and drain condensate anytime during operation. This is the reason traps are sometimes called automatic drain valves. A steam trap should

Alesson

1995-01-01

241

Note: Toward multiple addressable optical trapping  

NASA Astrophysics Data System (ADS)

We describe a setup for addressable optical trapping in which a laser source is focused on a digital micromirror device and generates an optical trap in a microfluidic cell. In this paper, we report a proof-of-principle single beam/single micromirror/single three-dimensional trap arrangement that should serve as the basis for a multiple-trap instrument.

Faustov, Alexei R.; Webb, Michael R.; Walt, David R.

2010-02-01

242

The RF spectroscopy of trapped neutral atoms  

NASA Astrophysics Data System (ADS)

We report the first observation of RF-induced transitions of trapped neutral atoms. An RF resonance curve for a sample of trapped Na atoms has been obtained by measuring the relative population of two trapped magnetic substates as a function of applied RF frequency. The shape of the resonance curve has been used to determine the energy distribution of the trapped atoms.

Martin, A. G.; Helmerson, K.; Bagnato, V. S.; Lafyatis, G. P.; Pritchard, D. E.

1988-11-01

243

The principle of equivalence reconsidered: assessing the relevance of the principle of equivalence in prison medicine.  

PubMed

In this article we critically examine the principle of equivalence of care in prison medicine. First, we provide an overview of how the principle of equivalence is utilized in various national and international guidelines on health care provision to prisoners. Second, we outline some of the problems associated with its applications, and argue that the principle of equivalence should go beyond equivalence to access and include equivalence of outcomes. However, because of the particular context of the prison environment, third, we contend that the concept of "health" in equivalence of health outcomes needs conceptual clarity; otherwise, it fails to provide a threshold for healthy states among inmates. We accomplish this by examining common understandings of the concepts of health and disease. We conclude our article by showing why the conceptualization of diseases as clinical problems provides a helpful approach in the delivery of health care in prison. PMID:24978402

Jotterand, Fabrice; Wangmo, Tenzin

2014-07-01

244

Universal collisional activation ion trap mass spectrometry  

DOEpatents

A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

McLuckey, S.A.; Goeringer, D.E.; Glish, G.L.

1993-04-27

245

Universal collisional activation ion trap mass spectrometry  

DOEpatents

A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator. A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means; introducing into the ion trapping means a bath gas; and, generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.

McLuckey, Scott A. (Oak Ridge, TN); Goeringer, Douglas E. (Oak Ridge, TN); Glish, Gary L. (Oak Ridge, TN)

1993-01-01

246

Effect of bait in live trapping Peromyscus  

USGS Publications Warehouse

SUMMARY: Evidence from live trapping tests indicated that Peromyscus leucopus did not leave their home ranges because of the attraction of trap bait in nearby areas. A trap line down the center of a heavily live-trapped area caught as many mice before the area trapping as afterward. Thus, there was reason to believe that the area trapping did not serve to pre-bait the mice. Two unbaited lines of live traps caught an equal number of Peromyscus. When one line was baited with rolled oats and peanut butter the efficiency of the traps was improved to the extent that the baited line captured more than twice as many mice as the unbaited line. It is concluded that for the species and habitat tested it is safe to make population calculations based on the assumption that the animals remain within their home ranges and do not tend to move into the trapped area because of the attraction of the trap bait.

Stickel, L.F.

1948-01-01

247

Equivalent magnetization over the World Ocean  

NASA Astrophysics Data System (ADS)

In another presentation (Hamoudi et al., this meeting), we present the construction of a new candidate for the World Digital Magnetic Anomaly Map (WDMAM) over oceanic areas. This map is based on: (a) a more realistic forward modeling of the marine magnetic anomalies which includes remanent magnetization vectors taking into account the age and motion of the oceanic lithosphere; (b) evaluation of the equivalent magnetization by comparison of the synthetic and observed anomalies along ship tracks; and (c) adjustment of the synthetic anomaly maps using this equivalent magnetization prior to merging with the observed anomalies. A by-product of this approach is a global distribution of equivalent magnetization over the World's Ocean. Note that, because no global basement map exists for the oceanic areas, we assume a uniform, 5 km-deep and 1 km-thick magnetized layer for the forward model. The resulting equivalent magnetization is therefore relative to this over-simplistic magnetic source. A first observation is that, within the hypotheses of the forward model, the average equivalent magnetization is about 3 A/m, a value which compares well with the Natural Remanent Magnetization (NRM) measured on ancient basalt samples. As expected, the mid-ocean ridges are marked by stronger equivalent magnetizations, an observation which reflects both the stronger NRM measured at ridge axes and their shallower bathymetry (not taken into account in our forward model). More interesting is the observation of significant along-axis variations. In the North Atlantic Ocean, the Kolbeinsey and Reykjanes ridges around Iceland are marked by a very strong equivalent magnetization and the Azores Plateau by a strong one as well.. Again this may reflect the combined effect of shallower seafloor, thicker and/or more magnetized basaltic layer at hotspots. In contrast, the areas between 45 and 55°N and between 0 and 10°N (Equatorial FZ) correspond to a weak equivalent magnetization. Further south, the Mid-Atlantic Ridge displays a more uniform signature, although off-axis variations seem associated to the Tristan and St Helena hotspots. In the Indian Ocean, a strong equivalent magnetization characterizes areas of hotspot-ridge interaction such as the Gulf of Aden, the Central Indian Ridge near Rodrigues Island, the Southwest Indian Ridge near Marion Island, and the Southeast Indian Ridge near St Paul and Amsterdam Islands. A weaker one is observed in colder area, at the Australian-Antarctic Discordance and around the Rodrigues Triple Junction. The Pacific Ocean is characterized by a generally stronger equivalent magnetization, both near ridges and in abyssal plains. Time variations, i.e. along seafloor spreading flowlines, are apparent across the Mid-Atlantic and Pacific-Antarctic ridges, with highs near the ridge axis (younger than 10 Ma) and between ~83 and 60 Ma, just after the Cretaceous Normal Superchron and lows between ~60 and 10 Ma. The Mesozoic basins of the Pacific and Atlantic oceans show a weaker equivalent magnetization before ~155 Ma and a stronger one after. Basins covered by thick sediments such as the Bengal Bay, Great Australian Bight, Nova Scotia Basin, and Western Somali Basin show a very weak equivalent magnetization, reflecting both a deeper basement and a possible thermal demagnetization. Some of these variations coincide with satellite magnetic anomalies.

Dyment, J.; Hamoudi, M.; Choi, Y.; Thebault, E.; Quesnel, Y.; Roest, W. R.; Lesur, V.

2012-12-01

248

The trapped radiation handbook, change 3. [Effects of trapped radiation on spacecraft systems  

Microsoft Academic Search

Contents: The Magnetosphere; The Geomagnetic field; The Motion of charged particles in the earth's magnetic field; Trapped radiation population; Sources and losses of trapped particles; History of artificial radiation belts; particle injection by nuclear detonations; Effects of trapped radiation on spacecraft systems; Synchrotron radiation from electrons trapped in the earth's magnetic field; Vulnerability of operational systems to trapped radiation; Supplementary

J. B. Cladis; G. T. Davidson; L. L. Newkirk

1974-01-01

249

The cellular origin of the lymphocyte trap  

PubMed Central

We investigated the cellular requirements for lymphocyte trapping. Depletion of lymphocyte populations selectively or indiscriminately did not affect the ability of animals to trap. The variety of materials which initiate trapping was also studied and this information, coupled with the resistance of `trapping' to severe lymphocyte depletion, is consistent with the hypothesis that the macrophage may be the central cell in initiating the trapping of lymphocytes after antigen stimulation.

Frost, P.; Lance, E. M.

1974-01-01

250

An innovative mosquito trap for testing attractants.  

PubMed

We describe a simple trap modification for testing volatile attractants to collect flying mosquitoes. The trap uses a standard Centers for Disease Control and Prevention trap modified for release of test chemicals. Test chemicals and other materials can be added and removed easily without spills or cross contamination. In preliminary studies using lactic acid and octenol, modified traps collected 40% more mosquitoes than controls (n = 164 and n = 117, respectively). Modifications cost less than $2.00 per trap. PMID:22533089

Dees, William H; Sylvester, Terry L; Clark, Benjamin M; Canning, Linda D; Schultz, George W; Kline, Daniel L

2012-03-01

251

Real-time automated tracking and trapping system for sperm.  

PubMed

We have developed a microscope system for real-time single sperm tracking with an automated laser tweezers escape power assay. Phase contrast images of swimming sperm are digitized to the computer at video rate. The custom algorithm creates a region of interest centered about a sperm in response to a mouse click and performs all subsequent tasks autonomously. Microscope stage movement responds to feedback from video analysis of swimming sperm to center the sperm with respect to the field of view. For escape power assays, sperm are automatically relocated to the laser trap focus where they are held for a user-defined duration at fixed power, or held as laser power is gradually reduced. The sperm's position is automatically monitored to measure the laser power at which the sperm escapes the trap. Sperm are tracked for extended durations before and after laser trap experiments. Motility measurements including the curvilinear velocity and the absolute position of the sperm relative to the cell chamber are calculated and written to the hard drive at video rate. Experimental throughput is increased over 30 times compared to off-line data analysis. The efficacy of the "track and trap" algorithm is validated through examples and comparisons with the manually collected data. PMID:16892192

Shi, Linda Z; Nascimento, Jaclyn; Chandsawangbhuwana, Charlie; Berns, Michael W; Botvinick, Elliot L

2006-11-01

252

Testing the equivalence principle with unstable particles  

NASA Astrophysics Data System (ADS)

We develop a framework to test the equivalence principle under conditions where the quantum aspects of nature cannot be neglected, specifically in the context of interference phenomena with unstable particles. We derive the nonrelativistic quantum equation that describes the evolution of the wave function of unstable particles under the assumption of the validity of the equivalence principle and when small deviations are assumed to occur. As an example, we study the propagation of unstable particles in a COW experiment, and we briefly discuss the experimental implications of our formalism.

Bonder, Y.; Fischbach, E.; Hernandez-Coronado, H.; Krause, D. E.; Rohrbach, Z.; Sudarsky, D.

2013-06-01

253

Effects of noise and task loading on a communication task loading on a communication task  

NASA Astrophysics Data System (ADS)

Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

Orrell, Dean H., II

254

Trap induction and trapping in eight nematode-trapping fungi (Orbiliaceae) as affected by juvenile stage of Caenorhabditis elegans.  

PubMed

This study measured trap induction and trapping on agar disks as affected by juvenile stages (J1, J2, J3, and J4) of the nematode Caenorhabditis elegans and by species of nematode-trapping fungi. Eight species of nematode-trapping fungi belonging to the family Orbiliaceae and producing four kinds of traps were studied: adhesive network-forming Arthrobotrys oligospora, A. vermicola, and A. eudermata, constricting ring-forming Drechslerella brochopaga, and Dr. stenobrocha, adhesive column-forming Dactylellina cionopaga, and adhesive knob-forming Da. ellipsospora, and Da. drechsleri. The number of traps induced generally increased with increasing juvenile stages of C. elegans. The ability to capture the juveniles tended to be similar among isolates that produced the same kind of trap but differed among species that produced different kinds of traps. Trapping by Dr. stenobrocha and Da. cionopaga was correlated with trap number and with juvenile stage. A. oligospora and A. vermicola respectively captured more than 92 and 88% of the J1, J3, and J4 but captured a lower percentage of J2. The knob-producing isolates captured more younger than elder juveniles. Partial correlation analyses demonstrated that the trap induction of the most fungal species positively correlated with the juvenile size and motility, which was juvenile stage dependent. Overall, trap induction and trapping correlated with C. elegans juvenile stage (size and motility) in six species of trapping fungi. PMID:20146004

Xie, Hongyan; Aminuzzaman, F M; Xu, Lingling; Lai, Yiling; Li, Feng; Liu, Xingzhong

2010-06-01

255

Impurity color centers in quartz and trapped electron dating - Electron spin resonance, thermoluminescence studies.  

NASA Technical Reports Server (NTRS)

Investigation of impurity-related electron-hole traps that are known to be sensitive to ionizing radiations. Electron spin resonance (ESR) equivalent natural doses were determined for the Al hole trap in virgin specimens; the doses agreed with estimates based on published data for the Ge electron trap. The 0.17 deg/sec 180 and 300 C thermoluminescence (TL) peaks in natural specimens were found to have activation energies approximately correct for the Ge trap. The 300 C peak was also found to be correlated with annealing of the Ge electron resonance in gamma-irradiated, step-annealed specimens. Although the 300 C peak occurs in virgin specimens, the corresponding natural Ge electron resonance was not observed.

Mcmorris, D. W.

1971-01-01

256

Abduction in Classification Tasks  

Microsoft Academic Search

\\u000a The aim of this paper is to show how abduction can be used in classification tasks when we deal with incomplete data. Some\\u000a classifiers, even if based on decision tree induction like C4.5 1, produce as output a set of rules in order to classify new\\u000a given examples. Most of these rule-based classifiers make the assumption that at classification time

Maurizio Atzori; Paolo Mancarella; Franco Turini

2003-01-01

257

Solar Thermal Task Analysis  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) has provided this document which includes an overview of objectives and task analysis for individuals installing solar water and pool heating systems. Areas of expertise include working safely with solar hot water and pool heating systems, identifying systems and their components and installing equipment. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2011-06-14

258

Small Wind Task Analysis  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) has compiled this document which lists objectives and task analysis for small wind energy system installers. The document is divided into areas including of competencies such as conducting a wind energy site assessment, working safely with small wind energy systems and performing system checkouts and inspection. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2011-07-11

259

Mobile Thread Task Manager  

NASA Technical Reports Server (NTRS)

The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

2013-01-01

260

Laser Trapping of Radioactive Atoms  

NASA Astrophysics Data System (ADS)

Stuart Freedman conceived the idea of laser trapping radioactive atoms for the purpose of studying beta correlation effects. ``This is really the theorist's view of a radioactive source,'' as he fondly claimed. It is ideal because the atoms form a point source, compressed in both position and momentum space, with no material walls nearby. The Berkeley group succeeded in trapping ^21Na (half-life = 22 s) atoms [Lu et al., PRL 72, 3791 (1994)], and determined its beta-neutrino correlation coefficient a=0.5502(60) to be in agreement with the Standard Model [Vetter et al., PRC 77, 035502 (2008)]. Other groups have joined this effort with searches for scalar or tensor couplings in the weak interaction. Moreover, the technique has been extended to trap very short lived ^8He (0.1 s) to study its halo structure or the very long lived ^81Kr (230,000 yr) to map the movement of groundwater.

Lu, Zheng-Tian

2013-04-01

261

EQUIVALENCE RELATIONS AND DISTANCES BETWEEN HILBERT FRAMES  

Microsoft Academic Search

We study some equivalency relations between Hilbert frames and closed subspaces of l2(I). We dene also a distance between frames and we establish the geometric meaning of this metric. Finally we nd the closest and respectively the nearest tight frame to a given frame.

RADU BALAN

262

Equivalent weight of humic acid from peat  

USGS Publications Warehouse

By means of discontinuous titration, the equivalent weight of humic acid isolated from a peat was found to increase from 144 to 183 between the third and fifty-second day after the humic acid was dissolved. Infra-red studies showed that the material had probably condensed with loss of carbonyl groups. ?? 1960.

Pommer, A. M.; Breger, I. A.

1960-01-01

263

A Conjecture About Fermi-Bose Equivalence  

Microsoft Academic Search

This paper suggests that traditional fermi-bose quantum field theories (QFT)\\u000ain 3+1-D, like the standard model of physics, may often be exactly equivalent\\u000ato the limiting case of a family of bosonic QFT (BQFT) which generate soliton\\u000asolutions and are \\

Paul J. Werbos

2005-01-01

264

Identifiability and Equivalence of GLLIRM Models  

ERIC Educational Resources Information Center

The generalized logit-linear item response model (GLLIRM) is a linearly constrained nominal categories model (NCM) that computes the scale and intercept parameters for categories as a weighted sum of basic parameters. This paper addresses the problems of the identifiability of the basic parameters and the equivalence between different GLLIRM…

Revuelta, Javier

2009-01-01

265

The equivalent fundamental-mode source  

SciTech Connect

In 1960, Hansen analyzed the problem of assembling fissionable material in the presence of a weak neutron source. Using point kinetics, he defined the weak source condition and analyzed the consequences of delayed initiation during ramp reactivity additions. Although not clearly stated in Hansen`s work, the neutron source strength that appears in the weak source condition corresponds to the equivalent fundamental-mode source. In this work, we describe the concept of an equivalent fundamental-mode source and we derive a deterministic expression for a factor, g*, that converts any arbitrary source distribution to an equivalent fundamental-mode source. We also demonstrate a simplified method for calculating g* in subcritical systems. And finally, we present a new experimental method that can be employed to measure the equivalent fundamental-mode source strength in a multiplying assembly. We demonstrate the method on the zero-power, XIX-1 assembly at the Fast Critical Assembly (FCA) Facility, Japan Atomic Energy Research Institute (JAERI).

Spriggs, G.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [Univ. of New Mexico, Albuquerque, NM (United States); Busch, R.D. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Sakurai, Takeshi; Okajima, Shigeaki [Japan Atomic Research Institute, Tokai (Japan)] [Japan Atomic Research Institute, Tokai (Japan)

1997-02-01

266

The Ricardian equivalence hypothesis: evidence from Bangladesh  

Microsoft Academic Search

This article examines the Ricardian equivalence hypothesis (REH) and its sources of failure in the case of Bangladesh using various theoretical specifications, annual data from 1974–2001 and linear and nonlinear time series techniques. The general findings tend to invalidate the REH: a finite time horizon and the presence of liquidity-constrained individuals are the sources of deviation from the REH. Empirical

Jalal U. Siddiki

2010-01-01

267

Procedures for Determining the Equivalence of Measures.  

ERIC Educational Resources Information Center

Eight different methods are reviewed for determining whether two or more tests are equivalent measures. These methods vary in restrictiveness from the Wilks-Votaw test of compound symmetry (which requires that all means, variances, and covariances are equal), to Joreskog's theory of congeneric tests (which requires only that the tests are measures…

Dunivant, Noel

268

TNT Equivalency of Cyclotol 70/30.  

National Technical Information Service (NTIS)

Peak side-on blast overpressure and scaled positive impulse were measured for Cyclotol 70/30 using configurations that simulate in-plant processing and shipping containers. The equivalency testing addressed the hopper configuration at the end of the casti...

L. Mars

1982-01-01

269

Electrophysiological Correlates of Stimulus Equivalence Processes  

ERIC Educational Resources Information Center

Research reported here concerns neural processes relating to stimulus equivalence class formation. In Experiment 1, two types of word pairs were presented successively to normally capable adults. In one type, the words had related usage in English (e.g., uncle, aunt). In the other, the two words were not typically related in their usage (e.g.,…

Haimson, Barry; Wilkinson, Krista M.; Rosenquist, Celia; Ouimet, Carolyn; McIlvane, William J.

2009-01-01

270

Structural equivalence of individuals in social networks  

Microsoft Academic Search

The aim of this paper is to understand the interrelations among relations within concrete social groups. Social structure is sought, not ideal types, although the latter are relevant to interrelations among relations. From a detailed social network, patterns of global relations can be extracted, within which classes of equivalently positioned individuals are delineated. The global patterns are derived algebraically through

François Lorrain; Harrison C. White

1971-01-01

271

Asymptotic equivalence of abstract impulsive differential equations  

Microsoft Academic Search

The notion of (h, k)-dichotomy is introduced, which is a generalization of the classical exponential dichotomy. By means of the Schauder-Tychonoff theorem an asymptotic equivalence is proved between a linear impulsive differential equation which is (h, k)-dichotomous and the corresponding perturbed nonlinear equation.

D. D. Bainov; S. I. Kostadinov; A. D. Myshkis

1996-01-01

272

Are All Wrong FCI Answers Equivalent?  

Microsoft Academic Search

The Force Concept Inventory (FCI) has been efficiently used to assess conceptual learning in mechanics. Each FCI question has one Newtonian answer and four wrong answers (distracters). Researchers and practitioners most frequently use measures of total score to assess learning. Yet, are all wrong answers equivalent? We conducted Latent Markov Chain Modeling (LMCM) analyses of all choices (right and wrong)

Helena Dedic; Steven Rosenfield; Nathaniel Lasry

2010-01-01

273

Learning a Mahalanobis Metric from Equivalence Constraints  

Microsoft Academic Search

Many learning algorithms use a metric defined over the input space as a principal tool, and their performance critically depends on the quality of this metric. We address the problem of learning metrics using side-information in the form of equivalence constraints. Unlike labels, we demonstrate that this type of side-information can sometimes be automatically obtained without the need of human

Aharon Bar-Hillel; Tomer Hertz; Noam Shental; Daphna Weinshall

2005-01-01

274

Error equivalence theory for manufacturing process control  

Microsoft Academic Search

Due to uncertainty in manufacturing processes, applied probability and statistics have been widely applied for quality and productivity improvement. In spite of significant achievements made in causality modeling for control of process variations, there exists a lack of understanding on error equivalence phenomenon, which concerns the mechanism that different error sources result in identical variation patterns on part features. This

Hui Wang

2007-01-01

275

Derivation of Biomonitoring Equivalents for cyfluthrin  

Microsoft Academic Search

Recent efforts worldwide have resulted in a growing database of measured concentrations of chemicals in blood and urine samples taken from the general population. However, few tools exist to assist in the interpretation of the measured values in a health risk context. Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite

Sean M. Hays; Lesa L. Aylward; Michelle Gagné; Kannan Krishnan

2009-01-01

276

Biomonitoring Equivalents for bisphenol A (BPA)  

Microsoft Academic Search

Recent efforts worldwide have resulted in a growing database of measured concentrations of chemicals in blood and urine samples taken from the general population. However, few tools exist to assist in the interpretation of the measured values in a health risk context. Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite

Kannan Krishnan; Michelle Gagné; Andy Nong; Lesa L. Aylward; Sean M. Hays

2010-01-01

277

New Guard: A Service-Equivalent Force.  

National Technical Information Service (NTIS)

This thesis proposes that the National Guard is a service-equivalent force that requires expanded authorities to develop capabilities for its dual- role mission. The paper provides an in-depth analysis of the historical role of the colonial militia and it...

J. E. Scalf

2012-01-01

278

SUPPORT FOR USEPA'S PATHOGEN EQUIVALENCY COMMITTEE  

EPA Science Inventory

This presentation will discuss recommended and new resources for the USEPA's Pathogen Equivalency Committee including: 1) Committee's creation in 1985 and its purpose 2) Drexel University Professor Chuck Haas' 2001 report (Assessment of the PEC Process) and its findings 3) NAS/NR...

279

Equivalent Circuit Modeling of Hysteresis Motors.  

National Technical Information Service (NTIS)

We performed a literature review and found that many equivalent circuit models of hysteresis motors in use today are incorrect. The model by Miyairi and Kataoka (1965) is the correct one. We extended the model by transforming it to quadrature coordinates,...

B. A. Kirkendall E. T. Scharlemann J. J. Nitao

2009-01-01

280

Equivalence Postulate and Quantum Origin of Gravitation  

Microsoft Academic Search

We suggest that quantum mechanics and gravity are intimately related. In particular, we investigate the quantum Hamilton-Jacobi equation in the case of two free particles and show that the quantum potential, which is attractive, may generate the gravitational potential. The investigation, related to the formulation of quantum mechanics based on the equivalence postulate, is based on the analysis of the

Marco Matone; G. Galilei

2000-01-01

281

Equivalence Relations, Contextual Control, and Naming  

ERIC Educational Resources Information Center

This paper reports two experiments that investigated the role of verbal behavior in the emergence and generalization of contextually controlled equivalence classes. During both experiments, participants were trained with two different combinations of the same easily nameable, yet formally unrelated, pictorial stimuli. Match-to-sample baselines for…

Randell, Tom; Remington, Bob

2006-01-01

282

Dysprosium magneto-optical traps  

SciTech Connect

Magneto-optical traps (MOTs) of highly magnetic lanthanides open the door to explorations of novel phases of strongly correlated matter such as lattice supersolids and quantum liquid crystals. We recently reported the first MOTs of the five high-abundance isotopes of the most magnetic atom, dysprosium. Described here are details of the experimental technique employed for repumper-free Dy MOTs containing up to half a billion atoms. Extensive characterization of the MOTs' properties--population, temperature, loading, metastable decay dynamics, and trap dynamics--is provided.

Youn, Seo Ho; Lu Mingwu; Ray, Ushnish; Lev, Benjamin L. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080 (United States)

2010-10-15

283

Optical trapping for analytical biotechnology.  

PubMed

We describe the exciting advances of using optical trapping in the field of analytical biotechnology. This technique has opened up opportunities to manipulate biological particles at the single cell or even at subcellular levels which has allowed an insight into the physical and chemical mechanisms of many biological processes. The ability of this technique to manipulate microparticles and measure pico-Newton forces has found several applications such as understanding the dynamics of biological macromolecules, cell-cell interactions and the micro-rheology of both cells and fluids. Furthermore we may probe and analyse the biological world when combining trapping with analytical techniques such as Raman spectroscopy and imaging. PMID:22154469

Ashok, Praveen C; Dholakia, Kishan

2012-02-01

284

Avoiding the performance improvement trap.  

PubMed

Hospitals today can all too easily fall into a performance improvement trap if they do not adequately consider how best to approach efforts to improve performance. To ensure that such efforts will be effective, hospital leaders should first understand the reasons why an organization can stumble into this trap. Reasons that improvement initiatives can fall short include the absence of coherent strategy, an inability to distinguish between action and results, and a disjointed use of performance improvement tools in isolation rather than as part of a coordinated effort. PMID:22734325

Betka, Robert D

2012-06-01

285

Random walk theory of a trap-controlled hopping transport process.  

PubMed

A random walk theory of hopping motion in the presence of a periodic distribution of traps is presented. The solution of the continuous-time random walk equations is exact and valid for arbitrary intersite interactions and trap concentration. The treatment is shown to be equivalent to an exact solution of the master equation for this trapping problem. These interactions can be a general function of electric field and are not restricted to nearest neighbors. In particular, with the inclusion of trap-to-trap interactions, as well as trap-to-host interactions, an exact treatment of the change from one hopping channel to another has been obtained. The trap-modulated propagator has been derived in terms of a type of Green's function that is introduced. The results are specialized to spatial moments of the propagator, from which expressions for the drift velocity and diffusion coefficient are obtained. Numerical results for the drift velocity are presented and shown to account for the change in hopping channels in recent transport measurements in mixed molecularly doped polymers. PMID:16592944

Scher, H; Wu, C H

1981-01-01

286

Ion storage in the rf octupole trap  

NASA Astrophysics Data System (ADS)

Confinement of ion clouds in an rf octupole ion trap is investigated with particular emphasis on the trapping stability, which is position dependent. Excitation spectra of trapped clouds of Ba+ ions are observed, and the kinetic energy of ion clouds is derived. The spatial extension of ion clouds is measured, providing the basis for an experimental study of the trapping stability. For ion clouds in an rf octupole trap the mean kinetic energy is smaller and the spatial extension is larger than in comparable Paul traps.

Walz, J.; Siemers, I.; Schubert, M.; Neuhauser, W.; Blatt, R.; Teloy, E.

1994-11-01

287

Hydrodynamic trap for single particles and cells  

NASA Astrophysics Data System (ADS)

Trapping and manipulation of microscale and nanoscale particles is demonstrated using the sole action of hydrodynamic forces. We developed an automated particle trap based on a stagnation point flow generated in a microfluidic device. The hydrodynamic trap enables confinement and manipulation of single particles in low viscosity (1-10 cP) aqueous solution. Using this method, we trapped microscale and nanoscale particles (100 nm-15 ?m) for long time scales (minutes to hours). We demonstrate particle confinement to within 1 ?m of the trap center, corresponding to a trap stiffness of ~10-5-10-4 pN/nm.

Tanyeri, Melikhan; Johnson-Chavarria, Eric M.; Schroeder, Charles M.

2010-05-01

288

Programmable trap geometries with superconducting atom chips  

SciTech Connect

We employ the hysteretic behavior of a superconducting thin film in the remanent state to generate different traps and flexible magnetic potentials for ultracold atoms. The trap geometry can be programed by externally applied fields. This approach for atom optics is demonstrated by three different trap types realized on a single microstructure: a Z-type trap, a double trap, and a bias-field-free trap. Our studies show that superconductors in the remanent state provide a versatile platform for atom optics and applications in ultracold quantum gases.

Mueller, T.; Fermani, R. [Nanyang Technological University, Division of Physics and Applied Physics, 21 Nanyang Link, Singapore 637371 (Singapore); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Zhang, B.; Chan, K. S.; Dumke, R. [Nanyang Technological University, Division of Physics and Applied Physics, 21 Nanyang Link, Singapore 637371 (Singapore); Lim, M. J. [Nanyang Technological University, Division of Physics and Applied Physics, 21 Nanyang Link, Singapore 637371 (Singapore); Department of Physics, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08028 (United States)

2010-05-15

289

Microfabricated linear Paul-Straubel ion trap  

DOEpatents

An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

Mangan, Michael A. (Albuquerque, NM) [Albuquerque, NM; Blain, Matthew G. (Albuquerque, NM) [Albuquerque, NM; Tigges, Chris P. (Albuquerque, NM) [Albuquerque, NM; Linker, Kevin L. (Albuquerque, NM) [Albuquerque, NM

2011-04-19

290

Sediment Nitrogen Trapping in a Mangrove Lagoon  

NASA Astrophysics Data System (ADS)

Quantification of the inputs, transformations and outputs of nitrogenous species in the sedimentary environment of Joyuda lagoon, a mangrove-lined coastal lagoon on the west coast of Puerto Rico, indicates a nitrogen mineralization rate equivalent to 6·5% of the total input to the sediment. Sedimentation of particulate matter provides a nitrogen flux of c . 855 ?moles N m -2 h -1. Nitrogen fixation in the sediments provides an additional 22 ?moles N m -2 h -1. Ammonium diffusion to the water column removes 50 ?moles N m -2 h -1 from the mineralized fraction, while only 5 ?moles N m -2 h -1 are removed from the system via denitrification. Overall, the data presented here indicate that oxidative bacterial metabolism (mineralization and nitrification) in Joyuda Lagoon is severely limited. Our results lend support to the hypothesis which describes the role of tropical coastal lagoons as nutrient and carbon traps, probably a requisite for the well-being of seagrasses and coral reefs prone to degradation by uncontrolled nutrient inputs.

Morell, J. M.; Corredor, J. E.

1993-08-01

291

New Recommendations for Dose Equivalent. Proposed Recommendations of ICRU and ICRP on the Determination of Dose Equivalent.  

National Technical Information Service (NTIS)

In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the i...

G. Bengtsson

1985-01-01

292

Representing Identity and Equivalence for Scientific Data  

NASA Astrophysics Data System (ADS)

Matters of equivalence and identity are central to the stewardship of scientific data. In order to properly prepare for and manage the curation, preservation and sharing of digitally-encoded data, data stewards must be able to characterize and assess the relationships holding between data-carrying digital resources. However, identity-related questions about resources and their information content may not be straightforward to answer: for example, what exactly does it mean to say that two files contain the same data, but in different formats? Information content is frequently distinguished from particular representations, but there is no adequately developed shared understanding of what this really means and how the relationship between content and its representations hold. The Data Concepts group at the Center for Informatics Research in Science and Scholarship (CIRSS), University of Illinois at Urbana Champaign, is developing a logic-based framework of fundamental concepts related to scientific data to support curation and integration. One project goal is to develop precise accounts of information resources carrying the same data. We present two complementary conceptual models for information representation: the Basic Representation Model (BRM) and the Systematic Assertion Model (SAM). We show how these models provide an analytical account of digitally-encoded scientific data and a precise understanding of identity and equivalence. The Basic Representation Model identifies the core entities and relationships involved in representing information carried by digital objects. In BRM, digital objects are symbol structures that express propositional content, and stand in layered encoding relationships. For example, an RDF description may be serialized as either XML or N3, and those expressions in turn may be encoded as either UTF-8 or UTF-16 sequences. Defining this encoding stack reveals distinctions necessary for a precise account of identity and equivalence relationships. The Systematic Assertion Model focuses on key provenance events through which propositional content and symbol structures acquire the status of data content and data, respectively. Attention is on events such as a selection of symbols to express propositional content, or an appeal to observational evidence to advance a claim. SAM explicitly identifies data as the primary form of expression the one directly expressing content for a systematic assertion, an assertion where claims are warranted by an observation or a computation event. Under these models, equivalence relationships may hold between different data expressing the same content, or between different encodings of the same data. Equivalence relationships also hold among different data supporting the same claim and when contrasting claims are based on the same observations. SAM and BRM support a fine-grained characterization of scientific equivalence relationships that can be documented through ordinary data stewardship practices.

Wickett, K. M.; Sacchi, S.; Dubin, D.; Renear, A. H.

2012-12-01

293

Soil Activated Trap Door Dibble.  

National Technical Information Service (NTIS)

The device is adapted for use in mechanized plant setting machines used in the agricultural industry. A dibble, formed by a u-shaped channel, utilizing a hinged pressure plate which, upon contact with the ground, mechanically opens a trap door within the ...

W. Moden T. Chappell W. L. DeWitt

1977-01-01

294

Electrical Traps in Microwave Materials.  

National Technical Information Service (NTIS)

This program was the final year of a three-year program to identify the sources of trapping centers in gallium arsenide semiconductor devices, to correlate this evidence with device effects and to eliminate or minimize these effects. During the first year...

L. H. Holway M. Adlerstein

1978-01-01

295

Trap loss in photoassociative spectroscopy.  

NASA Astrophysics Data System (ADS)

Measurements of photoassociative spectroscopy in a gas of lithium atoms at ultralow temperatures have been carried out (E.R.I Abraham, N.W.M. Ritchie, W.I. McAlexander, and R.G. Hulet, J. Chem. Phys. 103), 7773 (1995); E.R.I Abraham, W.I. McAlexander, J.M. Gerton, R.G. Hulet, R. Côté, and A. Dalgarno, Phys. Rev. A 53, R3713 (1996).. In the experiments, photons are absorbed into high vibrational levels of excited electronic singlet and triplet states of Li2 (R. Côté, A. Dalgarno, Y. Sun, and R.G. Hulet, Phys. Rev. Lett. 74), 3581 (1995).. The excited vibrational levels decay by spontaneous emission into the vibrational continuum and the discrete vibrational levels of the ground electronic states (R. Côté and A. Dalgarno, to be published in Phys. Rev. A.). Decay into the vibrational continuum can produce atoms with sufficient kinetic energy to escape the trap, while spontaneous emission into discrete levels produces molecules no longer trapped. We explore the trap loss from spontaneous emission as a function of the trap depth as well as the excited vibrational levels considered. The analysis is conducted for the singlet and triplet transitions for both ^6Li and ^7Li isotopes.

Côté, Robin; Dalgarno, A.

1997-04-01

296

Poverty Traps and Climate Change  

Microsoft Academic Search

We use a demo-economic model to examine the question of whether climate change could widen or deepen poverty traps. The model includes two crucial mechanisms. Parents are risk averse when deciding how many children to have; fertility is high when infant survival is low. High fertility spreads scarce household resources thin, resulting in children being poorly educated. At the macro

Richard S. J. Tol

2011-01-01

297

Effective trapping time of electrons and holes in different silicon materials irradiated with neutrons, protons and pions  

NASA Astrophysics Data System (ADS)

Silicon diodes fabricated on oxygenated and non-oxygenated silicon wafers with different bulk resistivities (1, 2 and 15 k? cm ) were irradiated with neutrons, pions and protons to fluences up to 2.4×10 14 n/cm-2. Effective trapping times for electrons and holes were determined by the charge correction method in the temperature range between -50°C and 20°C. The measured effective trapping probabilities scale linearly with fluence and decrease with increasing temperature. Irradiation with charged hadrons resulted in about 30% higher trapping probabilities than with neutrons at the same equivalent fluence. No dependence on silicon resistivity and oxygen concentration was found. The temperature dependence could be parameterized by a power-law scaling. Accelerated annealing at 60°C showed a 30% increase of hole trapping, measured at 10°C, and a decrease by about the same amount for electron trapping, both at a time scale of 10 h.

Kramberger, G.; Cindro, V.; Mandi?, I.; Mikuž, M.; Zavrtanik, M.

2002-04-01

298

Component Processes in Task Switching.  

ERIC Educational Resources Information Center

Studied task switching in 4 experiments involving 111 Israeli undergraduates. Results show the preparation for a task switch is not a by-product of general preparation by phasic alertness or predicting target onset and establish reconfiguration as a separate preparatory process. Suggests that there are at least three components of task switching…

Meiran, Nachshon; Chorev, Ziv; Sapir, Ayelet

2000-01-01

299

Learning the task allocation game  

Microsoft Academic Search

The distributed task allocation problem occurs in domains like web services, the grid, and other distributed systems. In this problem, the system consists of servers and mediators. Servers execute tasks and may dier in their capabilities, e.g. one server may take more time than the other in ex- ecuting the same task. Mediators act on behalf of users, which can

Sherief Abdallah; Victor R. Lesser

2006-01-01

300

Are All Wrong FCI Answers Equivalent?  

NSDL National Science Digital Library

The Force Concept Inventory (FCI) has been efficiently used to assess conceptual learning in mechanics. Each FCI question has one Newtonian answer and four wrong answers (distracters). Researchers and practitioners most frequently use measures of total score to assess learning. Yet, are all wrong answers equivalent? We conducted Latent Markov Chain Modeling (LMCM) analyses of all choices (right and wrong) on a subset of four FCI questions. LMCM assesses whether there are groups of students sharing similar patterns of responses. We infer that students sharing similar patterns also share similar reasoning. Our results show seven reasoning-groups. LMCM also computes probabilities of transition from one reasoning-group to another after instruction. Examining transitions between groups, we note a clear hierarchy. Groups at the top of the hierarchy are comprised of students that use Newtonian thinking more consistently but also choose certain wrong answers more frequently; suggesting that not all wrong answers are equivalent.

Dedic, Helena; Rosenfield, Steven; Lasry, Nathaniel

2011-01-01

301

University of Oregon Physics Applets: Equivalent Width  

NSDL National Science Digital Library

This applet will provide students with a database of real stellar and galaxy spectra and a tool from which the equivalent width of a spectral feature can be measured. The tool allows the wavelength range of the spectral feature to be marked and a reference continuum point can be chosen. From this, the integrated spectral flux of the feature is converted into its equivalent width and reported. This applet can be used for instance to show how the strength of hydrogen lines changes as a function of temperature of a stellar atmosphere, or how the strengths of some metal lines (Calcium) depend on this, or how the shape of the continuum changes with temperature.

Bothun, Gregory

2007-01-03

302

Neutron dose equivalent at electron storage rings  

SciTech Connect

Simple assumptions are used to predict the average dose equivalent from giant-resonance neutrons near a beam of circulating electrons. The methodology is derived assuming uniform beam loss around a circular ring and numerical results are given for a proposed set of storage ring parameters. Comparison is made to the two limiting cases of a point source and an infinite line source of photoneutrons. The dose equivalent at 1 m from the ring is calculated as a function of concrete shielding thickness and uncertainties are discussed. By simple scaling, the method can be applied to any electron storage ring or circular accelerator, or, with suitable modification of the source term, to any device that approximates an isotropic ring source. 13 refs., 3 figs.

Swanson, W.P.

1985-08-01

303

Equivalent Theories of Liquid Crystal Dynamics  

NASA Astrophysics Data System (ADS)

There are two competing descriptions of nematic liquid crystal dynamics: the Ericksen-Leslie director theory and the Eringen micropolar approach. Up to this day, these two descriptions have remained distinct in spite of several attempts to show that the micropolar theory includes the director theory. In this paper we show that this is the case by using symmetry reduction techniques and introducing a new system that is equivalent to the Ericksen-Leslie equations and may include disclination dynamics. The resulting equations of motion are verified to be completely equivalent, although one of the two different reductions offers the possibility of accounting for orientational defects. After applying these two approaches to the ordered micropolar theory of Lhuiller and Rey, all the results are eventually extended to flowing complex fluids, such as nematic liquid crystals.

Gay-Balmaz, François; Ratiu, Tudor S.; Tronci, Cesare

2013-12-01

304

Satellite Test of the Equivalence Principle (STEP)  

NASA Technical Reports Server (NTRS)

This grant provided support for the STEP (Satellite Test of the Equivalence Principle) program between October 1991 and September 1993. STEP, previously supported by NASA under Grant NAG8-837 'A Satellite Test of the Equivalence Principle,' was selected by the European Space Agency for a Phase A study as a candidate for ESA's next medium size mission (M2). STEP was conceived as a joint NASA/ESA mission with equal participation by both agencies. ESA's contribution to the program would be the spacecraft; NASA would provide the launcher and half of the instrument, while the other half of the instrument would be provided by various European agencies. STEP was in competition with three other programs, INTEGRAL, PRISMA, and MARSNET. The final selection of a single mission for M2 took place in April 1993. STEP was not selected for M2 but made a very close second. The program is continuing in modified form.

Worden, Paul

1994-01-01

305

Do Organic Amendments Enhance the Nematode-Trapping Fungi Dactylellina haptotyla and Arthrobotrys oligospora?  

PubMed Central

Soil cages (polyvinyl chloride pipe with mesh-covered ends) were used to determine how the quantity of two organic amendments affected the nematode-trapping fungi Dactylellina haptotyla and Arthrobotrys oligospora, which were studied independently in two different vineyards. Each cage contained 80 cm³ of field soil (120 g dry weight equivalent), fungal inoculum (two alginate pellets, each weighing 1.9 mg and containing assimilative hyphae of one fungus), and dried grape or alfalfa leaves (0, 360, or 720 mg equivalent to 0, 4,500, or 9,000 kg/ha) with a C:N of 28:1 and 8:1, respectively. Cages were buried in the vineyards, recovered after 25 to 39 days, and returned to the laboratory where fungus population density and trapping were quantified. Dactylellina haptotyla population density and trapping were most enhanced by the smaller quantity of alfalfa amendment and were not enhanced by the larger quantity of alfalfa amendment. Arthrobotrys oligospora population density was most enhanced by the larger quantity of alfalfa amendment, but A. oligospora trapped few or no nematodes, regardless of amendment. Trapping and population density were correlated for D. haptotyla but not for A. oligospora.

Jaffee, B. A.

2004-01-01

306

Do Organic Amendments Enhance the Nematode-Trapping Fungi Dactylellina haptotyla and Arthrobotrys oligospora?  

PubMed

Soil cages (polyvinyl chloride pipe with mesh-covered ends) were used to determine how the quantity of two organic amendments affected the nematode-trapping fungi Dactylellina haptotyla and Arthrobotrys oligospora, which were studied independently in two different vineyards. Each cage contained 80 cm(3) of field soil (120 g dry weight equivalent), fungal inoculum (two alginate pellets, each weighing 1.9 mg and containing assimilative hyphae of one fungus), and dried grape or alfalfa leaves (0, 360, or 720 mg equivalent to 0, 4,500, or 9,000 kg/ha) with a C:N of 28:1 and 8:1, respectively. Cages were buried in the vineyards, recovered after 25 to 39 days, and returned to the laboratory where fungus population density and trapping were quantified. Dactylellina haptotyla population density and trapping were most enhanced by the smaller quantity of alfalfa amendment and were not enhanced by the larger quantity of alfalfa amendment. Arthrobotrys oligospora population density was most enhanced by the larger quantity of alfalfa amendment, but A. oligospora trapped few or no nematodes, regardless of amendment. Trapping and population density were correlated for D. haptotyla but not for A. oligospora. PMID:19262815

Jaffee, B A

2004-09-01

307

Tau-equivalence and equipercentile equating  

Microsoft Academic Search

Test scores that are not perfectly reliable cannot be strictly equated unless they are strictly parallel [Lord, 1980]. This fact implies that tau-equivalence can be lost if an equipercentile equating is applied to observed scores that are not strictly parallel. Seventy-two simulated testing conditions are produced to simulate equating tests with different difficulties and discriminations. Number-correct and trait metrics are

Wendy M. Yen

1983-01-01

308

Capacitors with low equivalent series resistance  

NASA Technical Reports Server (NTRS)

An electric double layer capacitor (EDLC) in a coin or button cell configuration having low equivalent series resistance (ESR). The capacitor comprises mesh or other porous metal that is attached via conducting adhesive to one or both the current collectors. The mesh is embedded into the surface of the adjacent electrode, thereby reducing the interfacial resistance between the electrode and the current collector, thus reducing the ESR of the capacitor.

Fleig, Patrick Franz (Inventor); Lakeman, Charles D. E. (Inventor); Fuge, Mark (Inventor)

2011-01-01

309

Comments on gauge equivalence in noncommutative geometry  

Microsoft Academic Search

We investigate the transformation from ordinary gauge field to noncommutative one which was introduced by N. Seiberg and E. Witten (hep-th\\/9908142). It is shown that the general transformation which is determined only by gauge equivalence has a path dependence in `theta-space'. This ambiguity is negligible when we compare the ordinary Dirac-Born-Infeld action with the noncommutative one in the U(1) case,

Tsuguhiko Asakawa; Isao Kishimoto

1999-01-01

310

Equivalence between reliability and factor of safety  

Microsoft Academic Search

Traditionally, geotechnical engineers have been practicing design approaches based on safety factors to account for uncertainties due to their simplicity. More recently, reliability-based design approaches emerge as a more reasonable and rigorous way of handling uncertainties. This research raises a fundamental question: “Are reliability and safety factor equivalent?” or “Does there exist a one-to-one functional relationship between reliability and safety

Jianye Ching

2009-01-01

311

Two Tests for the Equivalence Principle  

NASA Astrophysics Data System (ADS)

The question: "Is the equivalence principle (EP) a general principle" is examined by analyzing solutions to two cases: 1. The Twin Paradox, and 2. Does a static charge located in a gravitational field radiate? The solutions to these two cases are given first by using EP, and then by physical analysis of the system involved. The fact that the two methods yield the same solutions, may be considered as test cases for the validity of the EP.

Harpaz, Amos

2011-06-01

312

An Equivalent Circuit for Quantum Cascade Lasers  

NASA Astrophysics Data System (ADS)

A new simpler equivalent circuit model of a quantum cascade laser based on two level rate equations is presented. The model is valid for small and large signals. A realistic current voltage model based on experimental results is included in the circuit model. Incorporation of the current voltage characteristic makes the circuit model fully compatible with parasitics and drive electronics. The model is validated by comparison of simulated results with analytica results and large signal numerical results reported earlier.

Yong, Kelvin S. C.; Haldar, Manas K.; Webb, Jeffrey F.

2013-10-01

313

Quantum mechanics from an equivalence principle  

SciTech Connect

The authors show that requiring diffeomorphic equivalence for one-dimensional stationary states implies that the reduced action S{sub 0} satisfies the quantum Hamilton-Jacobi equation with the Planck constant playing the role of a covariantizing parameter. The construction shows the existence of a fundamental initial condition which is strictly related to the Moebius symmetry of the Legendre transform and to its involutive character. The universal nature of the initial condition implies the Schroedinger equation in any dimension.

Faraggi, A.E. [Univ. of Florida, Gainesville, FL (United States). Inst. for Fundamental Theory; Matone, M. [Univ. of Padova (Italy)

1997-05-15

314

Equivalent Circuit Modeling of Hysteresis Motors  

SciTech Connect

We performed a literature review and found that many equivalent circuit models of hysteresis motors in use today are incorrect. The model by Miyairi and Kataoka (1965) is the correct one. We extended the model by transforming it to quadrature coordinates, amenable to circuit or digital simulation. 'Hunting' is an oscillatory phenomenon often observed in hysteresis motors. While several works have attempted to model the phenomenon with some partial success, we present a new complete model that predicts hunting from first principles.

Nitao, J J; Scharlemann, E T; Kirkendall, B A

2009-08-31

315

Bipolar transistor equivalents in CMOS technology  

Microsoft Academic Search

A CMOS circuit element equivalent to a bipolar junction transistor (BJT) which provides symmetrical performances of npn\\/pnp and ideality factor programming is proposed. Simulation showed that the ?, and Early voltage are superior to those of a typical BJT below about 1.65 GHz in a 0.8 ?m CMOS technology and the fabricated prototype has 2.3×10-16 A of IS, 2.4 mA

Gyudong Kim; Min-Kyu Kim; Wonchan Kim; Abdesselam Bouzerdoum

1995-01-01

316

Enactment versus conceptual encoding: Equivalent item memory but different source memory  

PubMed Central

It has been suggested that performing a physical action (enactment) is an optimally effective encoding task, due to the incorporation of motoric information in the episodic memory trace, and later retrieval of that information. The current study contrasts old/new recognition of objects after enactment to a conceptual encoding task of cost estimation. Both encoding tasks yielded high accuracy, and robust differences in brain activity as compared to new objects, but no differences between encoding tasks. These results are not supportive of the idea that encoding by enactment leads to the spontaneous retrieval of motoric information. When participants were asked to discriminate between the two classes of studied objects during a source memory task, perform-encoded objects elicited higher accuracy and different brain activity than cost-encoded objects. The extent and nature of what was retrieved from memory thus depended on its utility for the assigned memory test: object information during the old/new recognition test, but additional information about the encoding task when necessary for a source memory test. Event-related potentials (ERPs) recorded during the two memory tests showed two orthogonal effects during an early (300-800 ms) time window: a differentiation between studied and unstudied objects, and a test-type (retrieval orientation) effect that was equivalent for old and new objects. Later brain activity (800-1300 ms) differentiated perform- from cost-encoded objects, but only during the source memory test, suggesting temporally distinct phases of retrieval.

Senkfor, Ava J.; Van Petten, Cyma; Kutas, Marta

2008-01-01

317

Gap Thinking in Fraction Pair Comparisons Is Not Whole Number Thinking: Is This What Early Equivalence Thinking Sounds Like?  

ERIC Educational Resources Information Center

Gap thinking has been categorised as one of several whole number strategies that interfere with early fraction understanding. This study showed that this claim is not supported by interview data of Grade 6 students' gap thinking explanations during a fraction pair comparison task. A correlation with equivalence performance was uncovered, leading…

Mitchell, Annie; Horne, Marj

2010-01-01

318

Whatever Gave You That Idea? False Memories Following Equivalence Training: A Behavioral Account of the Misinformation Effect  

PubMed Central

The misinformation effect is a term used in the cognitive psychological literature to describe both experimental and real-world instances in which misleading information is incorporated into an account of an historical event. In many real-world situations, it is not possible to identify a distinct source of misinformation, and it appears that the witness may have inferred a false memory by integrating information from a variety of sources. In a stimulus equivalence task, a small number of trained relations between some members of a class of arbitrary stimuli result in a large number of untrained, or emergent relations, between all members of the class. Misleading information was introduced into a simple memory task between a learning phase and a recognition test by means of a match-to-sample stimulus equivalence task that included both stimuli from the original learning task and novel stimuli. At the recognition test, participants given equivalence training were more likely to misidentify patterns than those who were not given such training. The misinformation effect was distinct from the effects of prior stimulus exposure, or partial stimulus control. In summary, stimulus equivalence processes may underlie some real-world manifestations of the misinformation effect.

Challies, Danna M; Hunt, Maree; Garry, Maryanne; Harper, David N

2011-01-01

319

Atomic Oxygen Task  

NASA Technical Reports Server (NTRS)

This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials & Processes (M&P) Laboratory is to provide the solutions to material problems facing present and future space missions. The objective of this work was to provide the necessary research for the design of specialized experimental test configurations and development of techniques for evaluating in-situ space environmental effects, including the effects of atomic oxygen and electromagnetic radiation on candidate materials. Specific tasks were performed to address materials issues concerning accelerated environmental testing as well as specifically addressing materials issues of particular concern for LDEF analysis and Space Station materials selection.

Hadaway, James B.

1997-01-01

320

50 CFR 31.16 - Trapping program.  

Code of Federal Regulations, 2013 CFR

...THE NATIONAL WILDLIFE REFUGE SYSTEM WILDLIFE SPECIES MANAGEMENT Terms and Conditions of Wildlife Reduction and Disposal § 31.16 ...as hereafter noted, persons trapping animals on wildlife refuge areas where trapping...

2013-10-01

321

Collisional activation with random noise in ion trap mass spectrometry  

SciTech Connect

Random noise applied to the end caps of a quadrupole ion trap is shown to be an effective means for the collisional activation of trapped ions independent of mass/charge ratio and number of ions. This technique is compared and contrasted with conventional single-frequency collisional activation for the molecular ion of N,N-dimethylaniline, protonated cocaine, the molecular anion of 2,4,6-trinitrotoluene, and doubly protonated neuromedin U-8. Collisional activation with noise tends to produce more extensive fragmentation than the conventional approach due to the fact that product ions are also kinetically excited in the noise experiment. The efficiency of the noise experiment in producing detectable product ions relative to the conventional approach ranges from being equivalent to being a factor of 3 less efficient. Furthermore, discrimination against low mass/charge product ions is apparent in the data from multiply charged biomolecules. Nevertheless, collisional activation with random noise provides a very simple means for overcoming problems associated with the dependence of single-frequency collisional activation on mass/charge ratio and the number of ions in the ion trap. 45 refs., 7 figs.

McLuckey, S.A.; Goeringer, D.E.; Glish, G.L. [Oak Ridge National Lab., TN (United States)

1992-07-01

322

Equivalent Structures on Sets: Equivalence Classes, Partitions and Fiber Structures of Functions  

ERIC Educational Resources Information Center

This study reports on how students can be led to make meaningful connections between such structures on a set as a partition, the set of equivalence classes determined by an equivalence relation and the fiber structure of a function on that set (i.e., the set of preimages of all sets {b} for b in the range of the function). In this paper, I first…

Hamdan, May

2006-01-01

323

Ghost Fishing by Blue Crab Traps  

Microsoft Academic Search

Ghost fishing by abandoned or lost traps for blue crab Callinectes sapidus was evaluated experimentally in the Timbalier Bay estuary, Louisiana. An average of 12.8 blue crabs per trap were captured by the initial baiting, and an additional 34.9 blue crabs later entered each subsequently unbaited trap; of the total captured, 25.8 died and 21.7 escaped per trap. The turnover

Vincent Guillory

1993-01-01

324

Guide to Orifice Plate Steam Traps  

SciTech Connect

This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are provided to highlight their capabilities and limitations. Finally, recommendations for using orifice plate steam traps are presented, and possible applications are identified.

Oland, C.B.

2001-01-11

325

An consideration on equivalent circuit of wireless power transmission  

Microsoft Academic Search

An equivalent circuit of wireless power transmission is discussed. We demonstrate that an input impedance of the wireless power transmission is expressed by a simple equivalent circuit. The equivalent circuit spells out how the resonant frequency is determined. The parameters in the equivalent circuit is found by using genetic algorithm so that the input impedance calculated by method of moment

Hiroshi Hirayama; Yuki Okuyama; Nobuyoshi Kikuma; Kunio Sakakibara

2010-01-01

326

Testing Equivalence in Communication Research: Theory and Application  

Microsoft Academic Search

Although equivalence testing is preferred when a researcher's goal is to support the null hypothesis (i.e., no substantial effect), equivalence tests are virtually unknown and unused in the communication field. This article provides the rationale for and theoretical background of equivalence testing and offers examples of equivalence tests for the independent and dependent groups t-test and tests of association using

René Weber; Lucy Popova

2012-01-01

327

Magnetic Model Trap Formation of Volyn  

Microsoft Academic Search

In the article technique of magnetic modelling trap formation of Volyn (north-west Ukraine) is considered. It is investigated magnetic properties of rock trap formation, anomalous magnetic field and connection of these parameters with a technique of maning model. The model of a magnetic field was made. The comparative analysis with others trap formations of the world was carried out. Introduction

M. V. Yusypiv

2004-01-01

328

Guide to Orifice Plate Steam Traps  

Microsoft Academic Search

This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and defines their unique functional and operational characteristics. The advantages and disadvantages associated with using orifice plate steam traps are

C. B. Oland

2001-01-01

329

Improvements on a Reliable Oak Seed Trap.  

National Technical Information Service (NTIS)

The need for seed trap longevity, capture of heavy seed, and protection from predation in several forest types for long-term studies of seed production prompted seed trap design improvements. Critical improvements were achieved by painting the trap with a...

C. N. Phillips M. K. Burke T. B. Hunnicutt

1995-01-01

330

A Review of Cuttlefish Basket Trap Fishery  

Microsoft Academic Search

While cuttlefish basket trap fishery is a traditional fishing activity with a long history, there has never been an article which comprehensively assesses this type of fishery. The present review compiles existing knowledge on cuttlefish trap fishery and the findings of interviews conducted with fishermen by the authors. It mainly covers such issues as the history of cuttlefish trap fishery,

Naohiko WATANUKI; Gunzo KAWAMURA

1999-01-01

331

Effectiveness comparison of multiple sticky-trap configurations for sampling Pseudacteon spp. phorid flies (Diptera: Phoridae).  

PubMed

A variety of traps have been developed for monitoring introduced populations of Pseudacteon spp. phorid flies (Diptera: Phoridae) across their established range in the United States. Such traps typically exploit common aspects of phorid fly biology and behavior, such as their attraction to live or dead red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), as well as the perching behavior of these parasitoids. However, populations of multiple species of phorid flies have been established in the United States to serve as biological control agents against S. invicta, and it is unclear if all trap designs are equally effective in sampling this variety of phorid species. This study investigated the effectiveness of six trap designs simultaneously during three sampling events in south-central Texas. Interactions between two species of phorid flies (Pseudacteon tricuspis Borgmeier and P. curvatus B.) and their hosts have been intensively studied at this location for over eight years. When analyzed independently, there were no significant differences in the mean number of P. curvatus or P. tricuspis phorids collected by any of the trap designs during any of the sampling events. However, when the total number of phorids collected were combined, significant trap performance differentials were observed during the October 2010 sampling event. Furthermore, there were significant differences among male flies during the September 2012 observation. Additionally, a trap component cost comparison is provided. The consistent and relatively equivalent performance of the phorid traps investigated in these trials suggests that all are appropriate for phorid surveillance, and cost and ease-of-use considerations may be the most important criteria when selecting a trap design. PMID:23905740

Puckett, R T; Calixto, A A; Reed, J J; McDonald, D L; Drees, B Bart; Gold, R E

2013-08-01

332

Influence of trap location on the efficiency of trapping in dendrimers and regular hyperbranched polymers  

NASA Astrophysics Data System (ADS)

The trapping process in polymer systems constitutes a fundamental mechanism for various other dynamical processes taking place in these systems. In this paper, we study the trapping problem in two representative polymer networks, Cayley trees and Vicsek fractals, which separately model dendrimers and regular hyperbranched polymers. Our goal is to explore the impact of trap location on the efficiency of trapping in these two important polymer systems, with the efficiency being measured by the average trapping time (ATT) that is the average of source-to-trap mean first-passage time over every staring point in the whole networks. For Cayley trees, we derive an exact analytic formula for the ATT to an arbitrary trap node, based on which we further obtain the explicit expression of ATT for the case that the trap is uniformly distributed. For Vicsek fractals, we provide the closed-form solution for ATT to a peripheral node farthest from the central node, as well as the numerical solutions for the case when the trap is placed on other nodes. Moreover, we derive the exact formula for the ATT corresponding to the trapping problem when the trap has a uniform distribution over all nodes. Our results show that the influence of trap location on the trapping efficiency is completely different for the two polymer networks. In Cayley trees, the leading scaling of ATT increases with the shortest distance between the trap and the central node, implying that trap's position has an essential impact on the trapping efficiency; while in Vicsek fractals, the effect of location of the trap is negligible, since the dominant behavior of ATT is identical, respective of the location where the trap is placed. We also present that for all cases of trapping problems being studied, the trapping process is more efficient in Cayley trees than in Vicsek fractals. We demonstrate that all differences related to trapping in the two polymer systems are rooted in their underlying topological structures.

Lin, Yuan; Zhang, Zhongzhi

2013-03-01

333

Scenario-Based Tasks  

NSDL National Science Digital Library

This page from The Experiential Learning Center provides a number of scenario-based tasks for use in the classroom or for professional development training. The materials are freely available for download and use and would be applicable to learners in a variety of subjects including software development, faculty professional development, office system applications/ICT, biology/bioinformatics, environmental studies, Python programming, engineering, network security/MIS, computational thinking and English writing. Instructor guides and other classroom instructional materials are provided. The project requests that educators let them know when these materials are used in order to track dissemination of the work and in order to inform the community about upcoming workshops and presentations.

2012-10-09

334

Trapping of radiation in plasmas  

SciTech Connect

The authors analyze the problem of radiation trapping (imprisonment) by the method of Holstein. The process is described by an integrodifferential equation which shows that the effective radiative decay rate of the system depends on the size and the shape of the active medium. Holstein obtains a global decay rate for a particular geometry by assuming that the radiating excited species evolves into a steady state spatial mode. The authors derive a new approximation for the trapped decay which has a space dependent decay rate and is easy to implement in a detailed computer simulation of a plasma confined within an arbitrary geometry. They analyze the line shapes that are relevant to a near-atmospheric-pressure mixture of He and Xe. This line-shape analysis can be utilized in either the Holstein formulae or the space-dependent decay approximation.

Riley, M.E.; Alford, W.J.

1995-06-01

335

Solute trapping in aluminum alloys  

SciTech Connect

The authors report the first measurements of solute trapping in metallic alloys. The nonequilibrium solute partition coefficient k was measured in several dilute aluminum alloys (Al-Cu, Al-Ge, Al-In, Al-Sn). Pulsed laser melting was used to bring about rapid plane-front solidification at velocities of 0.6--5.1 m/s. Time-resolved melt depths and solidification velocities were determined using the transient electrical conductance and optical reflectance techniques. The solute trapping model with the fewest free parameters that accounts for the measured velocity dependence of k is the Continuous Growth Model of Aziz and Kaplan. They have also identified an inverse correlation between the diffusive speed (the only free parameter in that model) and the equilibrium partition coefficient; this correlation might be used to estimate diffusive speeds for systems in which it has not been measured. A possible origin of such a correlation is discussed.

Smith, P.M.; Aziz, M.J. (Harvard Univ., Cambridge, MA (United States))

1994-10-01

336

Microscale ion trap mass spectrometer  

DOEpatents

An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

Ramsey, J. Michael (Knoxville, TN); Witten, William B. (Lancing, TN); Kornienko, Oleg (Lansdale, PA)

2002-01-01

337

Trapping and cooling of 174Yb+ ions in a microfabricated surface trap  

NASA Astrophysics Data System (ADS)

Trapped atomic ions are the leading candidate to act as individual quantum bits in a large quantum information processing system. Ion traps can be conformed to a two-dimensional surface, which provides a way to increase the number of ions while maintaining the ability to move individual ions in a two-dimensional grid. However, surface traps tend to suffer from shallow trap depths and higher motional heating rates. In this work, we report the design, fabrication, and testing of a simple gold-on-fused-silica ion trap optimized for a deep trapping potential and stable motional modes. The desirable trap characteristics include long lifetime, fully-compensated micromotion, and high secular trap frequencies that were measured using a trapped and cooled 174Yb+ ion. This trap design can be integrated with an optical cavity to enhance the ion-photon coupling.

Noek, Rachel; Kim, Taehyun; Mount, Emily; Baek, So-Young; Maunz, Peter; Kim, Jungsang

2013-08-01

338

Optical trapping in plant cells.  

PubMed

Optical tweezers allow noninvasive manipulation of subcellular compartments to study their physical interactions and attachments. By measuring (delay of) displacements, (semi-)quantitative force measurements within a living cell can be performed. In this chapter, we provide practical tips for setting up such experiments paying special attention to the technical considerations for integrating optical tweezers into a confocal microscope. Next, we describe some working protocols to trap intracellular structures in plant cells. PMID:24132436

Ketelaar, Tijs; de Ruijter, Norbert; Niehren, Stefan

2014-01-01

339

Trapper readies trap for lizard  

NASA Technical Reports Server (NTRS)

State-licensed animal trapper James Dean sets the open door of an animal trap on KSC. He hopes to catch a large monitor lizard spotted recently near S.R. 3, a route into the Center, by several area residents. The lizard is not a native of the area, and possibly a released pet. Dean is working with the cooperation of KSC and the Merritt Island National Wildlife Refuge.

2000-01-01

340

Lift enhancement by trapped vortex  

NASA Technical Reports Server (NTRS)

The viewgraphs and discussion of lift enhancement by trapped vortex are provided. Efforts are continuously being made to find simple ways to convert wings of aircraft from an efficient cruise configuration to one that develops the high lift needed during landing and takeoff. The high-lift configurations studied here consist of conventional airfoils with a trapped vortex over the upper surface. The vortex is trapped by one or two vertical fences that serve as barriers to the oncoming stream and as reflection planes for the vortex and the sink that form a separation bubble on top of the airfoil. Since the full three-dimensional unsteady flow problem over the wing of an aircraft is so complicated that it is hard to get an understanding of the principles that govern the vortex trapping process, the analysis is restricted here to the flow field illustrated in the first slide. It is assumed that the flow field between the two end plates approximates a streamwise strip of the flow over a wing. The flow between the endplates and about the airfoil consists of a spanwise vortex located between the suction orifices in the endplates. The spanwise fence or spoiler located near the nose of the airfoil serves to form a separated flow region and a shear layer. The vorticity in the shear layer is concentrated into the vortex by withdrawal of fluid at the suction orifices. As the strength of the vortex increases with time, it eventually dominates the flow in the separated region so that a shear or vertical layer is no longer shed from the tip of the fence. At that point, the vortex strength is fixed and its location is such that all of the velocity contributions at its center sum to zero thereby making it an equilibrium point for the vortex. The results of a theoretical analysis of such an idealized flow field are described.

Rossow, Vernon J.

1992-01-01

341

Ability and task constraint determinants of complex task performance  

Microsoft Academic Search

Previous research on basic information-processing tasks has suggested that there may be a dissociation between the underlying process determinants of task performance and associations with ability measures. This study investigates this dissociation in the context of a complex skill-learning task—an air traffic control simulation called TRACON. A battery of spatial, numerical, and perceptual speed ability tests were administered, along with

Phillip L. Ackerman; Anna T. Cianciolo

2002-01-01

342

Galilean equivalence for galactic dark matter.  

PubMed

Satellite galaxies are tidally disrupted as they orbit the Milky Way. If dark matter (DM) experiences a stronger self-attraction than baryons, stars will preferentially gain rather than lose energy during tidal disruption, leading to an enhancement in the trailing compared to the leading tidal stream. The Sgr dwarf galaxy is seen to have roughly equal streams, challenging models in which DM and baryons accelerate differently by more than 10%. Future observations and a better understanding of DM distribution should allow detection of equivalence violation at the percent level. PMID:17026024

Kesden, Michael; Kamionkowski, Marc

2006-09-29

343

Growing skull fractures and their craniofacial equivalents.  

PubMed

Growing skull fractures occur most commonly after head injury; however, their "craniofacial equivalents" may occur after neurosurgical or craniofacial operations in pediatric patients. Experience with five separate cases is reviewed, including one case that involved the anterior cranial base and presented with vertical dystopia and proptosis. Necessary contributing factors appear to include (1) cranial bone defect, (2) dural tear, and (3) expanding intracranial process (e.g., growth of the brain). Prompt recognition and the diagnosis of the problem are essential to prevent the development of progressive neurological complications. The pathophysiology and principles of surgical management of these complex problems are explored in detail. PMID:8601014

Havlik, R J; Sutton, L N; Bartlett, S P

1995-03-01

344

Dark matter and the equivalence principle  

NASA Technical Reports Server (NTRS)

If the dark matter in galaxies and clusters is nonbaryonic, it can interact with additional long-range fields that are invisible to experimental tests of the equivalence principle. The astrophysical and cosmological implications of a long-range force coupled only to the dark matter are discussed and rather tight constraints on its strength are found. If the force is repulsive (attractive), the masses of galaxy groups and clusters (and the mean density of the universe inferred from them) have been systematically underestimated (overestimated). Such an interaction also has unusual implications for the growth of large-scale structure.

Frieman, Joshua A.; Gradwohl, Ben-Ami

1991-01-01

345

Testing efficiency transfer codes for equivalence.  

PubMed

Four general Monte Carlo codes (GEANT3, PENELOPE, MCNP and EGS4) and five dedicated packages for efficiency determination in gamma-ray spectrometry (ANGLE, DETEFF, GESPECOR, ETNA and EFFTRAN) were checked for equivalence by applying them to the calculation of efficiency transfer (ET) factors for a set of well-defined sample parameters, detector parameters and energies typically encountered in environmental radioactivity measurements. The differences between the results of the different codes never exceeded a few percent and were lower than 2% in the majority of cases. PMID:19892558

Vidmar, T; Celik, N; Cornejo Díaz, N; Dlabac, A; Ewa, I O B; Carrazana González, J A; Hult, M; Jovanovi?, S; Lépy, M-C; Mihaljevi?, N; Sima, O; Tzika, F; Jurado Vargas, M; Vasilopoulou, T; Vidmar, G

2010-02-01

346

Equivalent beam modeling using numerical reduction techniques  

NASA Technical Reports Server (NTRS)

Numerical procedures that can accomplish model reductions for space trusses were developed. Three techniques are presented that can be implemented using current capabilities within NASTRAN. The proposed techniques accomplish their model reductions numerically through use of NASTRAN structural analyses and as such are termed numerical in contrast to the previously developed analytical techniques. Numerical procedures are developed that permit reductions of large truss models containing full modeling detail of the truss and its joints. Three techniques are presented that accomplish these model reductions with various levels of structural accuracy. These numerical techniques are designated as equivalent beam, truss element reduction, and post-assembly reduction methods. These techniques are discussed in detail.

Chapman, J. M.; Shaw, F. H.

1987-01-01

347

A collapsible trap for capturing ruffe  

USGS Publications Warehouse

A modified version of the Windermere trap was designed, constructed, and tested for its effectiveness in capturing ruffe Gymnocephalus cernuus. The inexpensive, lightweight, collapsible trap was easily deployed and retrieved from a small boat. Field tests conducted at the St. Louis River estuary in western Lake Superior in spring 1995 and 1996 indicated that the trap was effective in capturing ruffe. Proportions of the ruffe in trap and bottom trawl catches were similar in 1995 and 1996. This trap could be a useful tool in surveillance, monitoring, or control programs for ruffe or similar species, either to augment existing sampling programs or especially in situations where gillnetting or bottom trawling are not feasible.

Edwards, Andrew J.; Czypinski, Gary D.; Selgeby, James H.

1998-01-01

348

Electrodynamic trap for neutral polar particles  

SciTech Connect

A superposition of inhomogeneous static and rapidly oscillating electric fields is capable of trapping neutral particles with a permanent electric dipole moment. Detailed numerical simulations prove the validity and stability of our trapping scheme. Thin rods of barium titanate (BaTiO{sub 3}) are presented as an example for trapping on the macroscale. HC{sub 17}N, a polar molecule of astrophysical significance, is presented as an example for trapping on the microscale. For HC{sub 17}N and the parameters chosen, the depth of the trap is 40 mK.

Bluemel, R. [Department of Physics, Wesleyan University, Middletown, Connecticut 06459-0155 (United States)

2011-04-15

349

Optical trapping with photorefractive electric fields  

NASA Astrophysics Data System (ADS)

Trapping with evanescent fields has become an important tool in many research fields. Evanescent fields allow trapping of particles in close proximity to a surface. However, excitation of these waves may be cumbersome. Recently, trapping with photorefractive electric fields has been demonstrated using dielectric and metallic nano and microparticles. Excitation of these fields is straight forward and, in principle, can be excited with microwatt power level. In this work, we give a comparison of photorefractive and plasmonic trapping emphasizing its advantages and disadvantages. We show that single beam and holographic photorefractive photovoltaic trapping in LiNbO3 of microparticle in water is possible.

Torres-Hurtado, S. A.; Villegas-Vargas, B. M.; Korneev, N.; Ramirez-San-Juan, J. C.; Ramos-Garcia, R.

2012-10-01

350

Solar energy trapping with modulated silicon nanowire photonic crystals  

NASA Astrophysics Data System (ADS)

We demonstrate the efficacy of nanostructured thin film silicon solar cells to trap and absorb approximately 75% of all sunlight incident (400 nm-1200 nm) with an equivalent bulk thickness of only 1 micron of silicon. This is achieved by sculpting the collection zone into a three-dimensional, simple-cubic-symmetry, photonic crystal consisting of modulated silicon nanowires embedded in SiO2 and sitting on a quartz substrate with no metallic mirrors. A specific modulation of the radius of nanowires provides antireflection, strong light trapping, and back-reflection mechanisms in targeted spectral regions. This modulation is linear at the top of the nano-rods leading to nanocones at the solar cell to air boundary. These silicon nanocones are very good absorbers at short wavelengths and act as broadband coupler to a light-trapping region below at longer wavelengths. In the light trapping region the modulation is periodic to form a simple cubic photonic crystal exhibiting a broad spectrum of strong parallel interface refraction resonances. Here, light incident from most angles is deflected into slow group velocity modes with energy flow nearly parallel to the interface, long dwell times, and strong light intensity enhancement (up to 150 times the incident intensity) in specific regions. Finally, a stronger and chirped modulation of the nanowire underneath provides back-reflection by means of a one-dimensional depth-dependent photonic stop-gap. The possibility of absorbing light at energies below the electronic band gap of silicon is illustrated using a graded index SixGe1-x alloy in the bottom section of each nanowire. Each nanowire is amenable to a radial P-N junction for proximal charge carrier separation and efficient collection of photo-generated current.

Demésy, Guillaume; John, Sajeev

2012-10-01

351

AC electric trapping of neutral atoms  

NASA Astrophysics Data System (ADS)

We have demonstrated trapping of ultracold ground-state ^87Rb atoms in a macroscopic ac electric trap [1]. Trapping by ac electric fields has been previously achieved for polar molecules [2], as well as Sr atoms on a chip [3], and recently for Rb atoms in a three-phase electric trap [4]. Similar to trapping of ions in a Paul trap, three-dimensional confinement in an ac electric trap is obtained by switching between two saddle-point configurations of the electric field. For the first time, this dynamic confinement is directly visualized with absorption images taken at different phases of the ac switching cycle. Stable electric trapping is observed in a narrow range of switching frequencies around 60 Hz, in agreement with trajectory calculations. In a typical experiment, about 3 x 10^5 Rb atoms are trapped with lifetimes on the order of 9 s and trap depths of about 10 ?K. Additionally, we show that the atoms can be used to sensitively probe the electric fields in the trap by imaging the cloud while the fields are still on. References: 1. S. Schlunk et al., PRL 98, 223002 (2007) 2. H. L. Bethlem et al., PRA 74, 063403 (2006) 3. T. Kishimoto et al., PRL 96, 123001 (2006) 4. T. Rieger et al., PRL 99, 063001 (2007)

Marian, Adela; Schlunk, Sophie; Schoellkopf, Wieland; Meijer, Gerard

2008-05-01

352

Towards the unification of inference structures in medical diagnostic tasks.  

PubMed

The central purpose of artificial intelligence applied to medicine is to develop models for diagnosis and therapy planning at the knowledge level, in the Newell sense, and software environments to facilitate the reduction of these models to the symbol level. The usual methodology (KADS, Common-KADS, GAMES, HELIOS, Protégé, etc) has been to develop libraries of generic tasks and reusable problem-solving methods with explicit ontologies. The principal problem which clinicians have with these methodological developments concerns the diversity and complexity of new terms whose meaning is not sufficiently clear, precise, unambiguous and consensual for them to be accessible in the daily clinical environment. As a contribution to the solution of this problem, we develop in this article the conjecture that one inference structure is enough to describe the set of analysis tasks associated with medical diagnoses. To this end, we first propose a modification of the systematic diagnostic inference scheme to obtain an analysis generic task and then compare it with the monitoring and the heuristic classification task inference schemes using as comparison criteria the compatibility of domain roles (data structures), the similarity in the inferences, and the commonality in the set of assumptions which underlie the functionally equivalent models. The equivalences proposed are illustrated with several examples. Note that though our ongoing work aims to simplify the methodology and to increase the precision of the terms used, the proposal presented here should be viewed more in the nature of a conjecture. PMID:9550854

Mira, J; Rives, J; Delgado, A E; Martínez, R

1998-01-01

353

Evaluation of trapping-web designs  

USGS Publications Warehouse

The trapping web is a method for estimating the density and abundance of animal populations. A Monte Carlo simulation study is performed to explore performance of the trapping web for estimating animal density under a variety of web designs and animal behaviours. The trapping performs well when animals have home ranges, even if the home ranges are large relative to trap spacing. Webs should contain at least 90 traps. Trapping should continue for 5-7 occasions. Movement rates have little impact on density estimates when animals are confined to home ranges. Estimation is poor when animals do not have home ranges and movement rates are rapid. The trapping web is useful for estimating the density of animals that are hard to detect and occur at potentially low densities. ?? CSIRO 2005.

Lukacs, P. M.; Anderson, D. R.; Burnham, K. P.

2005-01-01

354

Temperature and trapping characterization of an acoustic trap with miniaturized integrated transducers--towards in-trap temperature regulation.  

PubMed

An acoustic trap with miniaturized integrated transducers (MITs) for applications in non-contact trapping of cells or particles in a microfluidic channel was characterized by measuring the temperature increase and trapping strength. The fluid temperature was measured by the fluorescent response of Rhodamine B in the microchannel. The trapping strength was measured by the area of a trapped particle cluster counter-balanced by the hydrodynamic force. One of the main objectives was to obtain quantitative values of the temperature in the fluidic channel to ensure safe handling of cells and proteins. Another objective was to evaluate the trapping-to-temperature efficiency for the trap as a function of drive frequency. Thirdly, trapping-to-temperature efficiency data enables identifying frequencies and voltage values to use for in-trap temperature regulation. It is envisioned that operation with only in-trap temperature regulation enables the realization of small, simple and fast temperature-controlled trap systems. The significance of potential gradients at the trap edges due to the finite size of the miniaturized transducers for the operation was emphasized and expressed analytically. The influence of the acoustic near field was evaluated in FEM-simulation and compared with a more ideal 1D standing wave. The working principle of the trap was examined by comparing measurements of impedance, temperature increase and trapping strength with impedance transfer calculations of fluid-reflector resonances and frequencies of high reflectance at the fluid-reflector boundary. The temperature increase was found to be moderate, 7°C for a high trapping strength, at a fluid flow of 0.5mms(-1) for the optimal driving frequency. A fast temperature response with a fall time of 8s and a rise time of 11s was observed. The results emphasize the importance of selecting the proper drive frequency for long term handling of cells, as opposed to the more pragmatic way of selecting the frequency of the highest acoustic output. Trapping was demonstrated in a large interval between 9 and 11.5MHz, while the main trapping peak displayed FWHM of 0.5MHz. A large bandwidth enables a more robust manufacturing and operation while allowing the trapping platform to be used in applications where the fluid wavelength varies due to external variations in fluid temperature, density and pressure. PMID:23497805

Johansson, Linda; Evander, Mikael; Lilliehorn, Tobias; Almqvist, Monica; Nilsson, Johan; Laurell, Thomas; Johansson, Stefan

2013-07-01

355

Cavity effect amplification in the recognition of dicarboxylic acids by initial ditopic H-bond formation followed by kinetic trapping  

SciTech Connect

Di[dihydroxotin(IV)] Troeger's base bis-porphyrin 1, a host molecule with two internal and two external guest interaction sites, binds {le} 1 equivalent of dicarboxylic acid quantitatively within the chiral cavity, a regioselectivity amplified by initial ditopic H-bond formation, followed by kinetic trapping.

Brotherhood, Peter R.; Wu, Richard A.-S.; Turner, Peter; Crossley, Maxwell J. (Sydney)

2008-04-02

356

Acoustic Bessel beam with combined optical trapping  

NASA Astrophysics Data System (ADS)

Whilst the main strength of optical trapping techniques is arguably its precision and dexterity, the complimentary technique of acoustic trapping offers massive scalability and potentially larger forces. Acoustic traps commonly use ultrasonic standing waves to trap particles within the nodes of a pressure field, often over distances upwards of a few cm. Here, an acoustic Bessel beam has been created using a piezoelectric cylinder whereby particles are trapped within the entire 14 mm-diameter of the transducer (1.5 cm2 trapping area). In optics, Bessel beams have the ability to trap particles over axial distances of several hundred microns. In this acoustic case, the Bessel function shape of the field is formed within the entire length of the cylinder (10 mm). Polymer spheres ranging from 1 ?m to 100 ?m in diameter are trapped simultaneously within the nodes of the standing wave field, in this case the concentric rings of a Bessel beam. The smaller particles within this field (< 5m) have also been trapped optically using a single beam optical tweezer, as the acoustic force scales such that it becomes comparable to that of the optical trap. This allows for a large range of particle sizes to be simultaneously trapped in a single device, and for large arrays (hundreds of mm2) to be formed acoustically within which particles can be individually optically trapped. This result demonstrates the complementarity of optical and acoustic trapping which makes it possible to trap large area arrays of particles whilst retaining the dexterity to manipulate individual particles.

Brodie, G. W. J.; Hughes, D. A.; Demore, C. E. M.; Spalding, G. C.; MacDonald, M. P.

2012-10-01

357

Task and work performance on Skylab missions 2, 3, and 4: Time and motion study: Experiment M151  

NASA Technical Reports Server (NTRS)

Human task performance was evaluated under weightlessness conditions during long duration space flight in order to study the characteristics of the adaptation function. Results show that despite pronounced variability in training schedules and in initial reaction to the Skylab environment, in-flight task performance was relatively equivalent among Skylab crews, and behavioral performance continued to improve from beginning to end of all missions.

Kubis, J. F.; Mclaughlin, E. J.; Jackson, J. M.; Rusnak, R.; Mcbride, G. H.; Saxon, S. V.

1977-01-01

358

Mass trapping of Prays nephelomima (Lepidoptera: Yponomeutidae) in citrus orchards: optimizing trap design and density.  

PubMed

The moth Prays nephelomima (Meirick) (Lepidoptera: Yponomeutidae) is a significant pest of citrus (Citrus spp.), and the recent identification of the female sex pheromone has enabled new direct control tactics to be considered. Six trap designs were compared for suitability in mass trapping, and Pherocon III delta traps were chosen to further evaluate mass trapping. A mass trapping field trial was carried out at five lemon, Citrus limon L., orchards to determine the effect of trap density on catch and rind spot damage on fruit. One plot (0.33-1.0 ha) of each of the five trap density treatments (3, 10, 30, 100, and 300 traps/ha) were operated at each orchard over 12 wk. Catch per trap was reduced as trap density increased and a mean of 12,000 and 16,000 males per ha were killed at the trap densities of 100 and 300 traps per ha, respectively. Increased trap density reduced the percentage of flowers infested with P. nephelomima larvae and reduced the number of moths emerging from flowers. The incidence of rindspot damage on fruit decreased from 45 to 16% as the density of traps increased from 3 to 100 traps per ha. Incidence (percentage of fruit with rindspot) and severity (number of rindspots per fruit) was similar at 100 and 300 traps per ha, indicating that the optimal trap density for reducing rindspot damage is likely to be between 30 and 100 traps per ha. Prospects for converting mass trapping to a lure and kill system are discussed. PMID:18767739

Jamieson, Lisa E; Suckling, David M; Ramankutty, Padmaja

2008-08-01

359

Hypercube matrix computation task  

NASA Technical Reports Server (NTRS)

A major objective of the Hypercube Matrix Computation effort at the Jet Propulsion Laboratory (JPL) is to investigate the applicability of a parallel computing architecture to the solution of large-scale electromagnetic scattering problems. Three scattering analysis codes are being implemented and assessed on a JPL/California Institute of Technology (Caltech) Mark 3 Hypercube. The codes, which utilize different underlying algorithms, give a means of evaluating the general applicability of this parallel architecture. The three analysis codes being implemented are a frequency domain method of moments code, a time domain finite difference code, and a frequency domain finite elements code. These analysis capabilities are being integrated into an electromagnetics interactive analysis workstation which can serve as a design tool for the construction of antennas and other radiating or scattering structures. The first two years of work on the Hypercube Matrix Computation effort is summarized. It includes both new developments and results as well as work previously reported in the Hypercube Matrix Computation Task: Final Report for 1986 to 1987 (JPL Publication 87-18).

Calalo, Ruel H.; Imbriale, William A.; Jacobi, Nathan; Liewer, Paulett C.; Lockhart, Thomas G.; Lyzenga, Gregory A.; Lyons, James R.; Manshadi, Farzin; Patterson, Jean E.

1988-01-01

360

Hypercube matrix computation task  

NASA Technical Reports Server (NTRS)

The Hypercube Matrix Computation (Year 1986-1987) task investigated the applicability of a parallel computing architecture to the solution of large scale electromagnetic scattering problems. Two existing electromagnetic scattering codes were selected for conversion to the Mark III Hypercube concurrent computing environment. They were selected so that the underlying numerical algorithms utilized would be different thereby providing a more thorough evaluation of the appropriateness of the parallel environment for these types of problems. The first code was a frequency domain method of moments solution, NEC-2, developed at Lawrence Livermore National Laboratory. The second code was a time domain finite difference solution of Maxwell's equations to solve for the scattered fields. Once the codes were implemented on the hypercube and verified to obtain correct solutions by comparing the results with those from sequential runs, several measures were used to evaluate the performance of the two codes. First, a comparison was provided of the problem size possible on the hypercube with 128 megabytes of memory for a 32-node configuration with that available in a typical sequential user environment of 4 to 8 megabytes. Then, the performance of the codes was anlyzed for the computational speedup attained by the parallel architecture.

Calalo, R.; Imbriale, W.; Liewer, P.; Lyons, J.; Manshadi, F.; Patterson, J.

1987-01-01

361

Task-dependent color discrimination  

NASA Technical Reports Server (NTRS)

When color video displays are used in time-critical applications (e.g., head-up displays, video control panels), the observer must discriminate among briefly presented targets seen within a complex spatial scene. Color-discrimination threshold are compared by using two tasks. In one task the observer makes color matches between two halves of a continuously displayed bipartite field. In a second task the observer detects a color target in a set of briefly presented objects. The data from both tasks are well summarized by ellipsoidal isosensitivity contours. The fitted ellipsoids differ both in their size, which indicates an absolute sensitivity difference, and orientation, which indicates a relative sensitivity difference.

Poirson, Allen B.; Wandell, Brian A.

1990-01-01

362

Machine Learning Task as a Diclique Extracting Task  

Microsoft Academic Search

As we know there exist several approaches and algorithms for data mining and machine learning task solution, for example, decision tree learning, artificial neural networks, Bayesian learning, instance-based learning, genetic algorithms, etc. They are effective and well-known and their base algorithms and main ideology are published. In this paper we present a new approach for machine learning (ML) task solution,

Rein Kuusik; Tarvo Treier; Grete Lind; Peeter Roosmann

2009-01-01

363

Primary Task Performance as Affected by Secondary Task Involvement.  

ERIC Educational Resources Information Center

This study proposed that performing a low-demand secondary task would improve a subject's control of attentional processes on a primary task of importance. Subjects were 60 public elementary school students 9, 10, or 11 years of age. Of these, 30 had been identified as learning disabled and 30 had been identified as non-learning-disabled. Each…

Williamson, Troy W.; Cochran, Samuel W.

364

Surface Color Perception and Equivalent Illumination Models  

PubMed Central

Vision provides information about the properties and identity of objects. The ease with which we make such judgments belies the difficulty of the information-processing task that accomplishes it. In the case of object color, retinal information about object reflectance is confounded with information about the illumination as well as about the object’s shape and pose. Because of these factors, there is no obvious rule that allows transformation of the retinal images of an object to a color representation that depends primarily on the object’s surface reflectance properties. Despite the difficulty of this task, however, under many circumstances object color appearance is remarkably stable across scenes in which the object is viewed. Here we review experiments and theory that aim to understand how the visual system stabilizes the color appearance of object surfaces. Our emphasis is on a class of models derived from explicit analysis of the computational problem of estimating the physical properties of illuminants and surfaces from the information available in the retinal image and experiments that test these models. We argue that this approach has considerable promise for allowing generalization from simplified laboratory experiments to richer scenes that more closely approximate natural viewing.

Brainard, David H.; Maloney, Laurence T.

2011-01-01

365

Measurement of LET distribution and dose equivalent on board the space shuttle STS-65  

NASA Technical Reports Server (NTRS)

Space radiation dosimetry measurements have been made on board the Space Shuttle STS-65 in the Second International Microgravity Laboratory (IML-2). In these measurements, three kinds of detectors were used; one is a newly developed active detector telescope called "Real-time Radiation Monitoring Device (RRMD)" utilizing silicon semi-conductor detectors and others are conventional detectors of thermoluminescence dosimeters (TLDs) and CR-39 plastic track detectors. Using the RRMD detector, the first attempt of real-time monitoring of space radiation has been achieved successfully for a continuous period of 251.3 h, giving the temporal variations of LET distribution, particle count rates, and rates of absorbed dose and dose equivalent. The RRMD results indicate that a clear enhancement of the number of trapped particles is seen at the South Atlantic Anomaly (SAA) without clear enhancement of dose equivalent, while some daily periodic enhancements of dose equivalent due to high LET particles are seen at the lower geomagnetic cutoff regions for galactic cosmic ray particles (GCRs). Therefore, the main contribution to dose equivalent is seen to be due to GCRs in this low altitude mission (300 km). Also, the dose equivalent rates obtained by TLDs and CR-39 ranged from 146.9 to 165.2 microSv/day and the average quality factors from 1.45 to 1.57 depending on the locations and directions of detectors inside the Space-lab at this highly protected orbit for space radiation with a small inclination (28.5 degrees) and a low altitude (300 km). The LET distributions obtained by two different detectors, RRMD and CR-39, are in good agreement in the region of 15-200 keV/mm and difference of these distributions in the regions of LET < 15 keV/mm and LET > 200 keV/mm can be explained by considering characteristics of CR-39 etched track formation especially for the low LET tracks.

Hayashi, T.; Doke, T.; Kikuchi, J.; Takeuchi, R.; Hasebe, N.; Ogura, K.; Nagaoka, S.; Kato, M.; Badhwar, G. D.

1996-01-01

366

Ion Trap in a Semiconductor Chip  

NASA Astrophysics Data System (ADS)

Current ion trap research is largely driven by the quest to build a quantum information processor, where quantum bits of information are stored in individual atomic ions and connected through a common interaction with their collective motion^1. Semiconductor processing techniques, particularly photolithography on integrated structures, allows the fabrication of ion traps which can host large numbers of qubits and shuttle ions between many separated trapping zones^2. Here we discuss the trapping of a single ion in an rf Paul trap fabricated on a monolithic GaAs heterostructure. Of particular note is that this trap is integrated on a chip and does not require any alignment or manual assembly. In addition to discussing the processing steps and electrical characteristics of the trap, we report measurements of heating of a single ion in the trap^3. Work supported by the Disruptive Technology Office under Army Research Office contract and the National Science Foundation ITR Program. 1. Cirac, J. I. & Zoller, P. Quantum computations with cold trapped ions. Phys Rev. Lett. 74, 4091-4094 (1995). 2. Kielpinski, D., Monroe, C., Wineland D. J. Architecture for a large scale ion trap quantum computer. Nature 417, 709-711 (2002). 3. D. Stick, W. K. Hensinger, S. Olmschenk, M. J. Madsen, K. Schwab, C. Monroe. Nature Phys. 2, 36-39 (2006).

Stick, Dan; Hensinger, Winfried; Olmschenk, Steven; Madsen, Martin; Schwab, Keith; Monroe, Chris

2006-05-01

367

A new neutron dose equivalent meter  

SciTech Connect

The design and performance of a new neutron dose equivalent meter or ``rem meter`` are described. Key design elements include a 6.38-inch diameter polyethylene moderator sphere loaded with Tungsten Carbide powder to 5% tungsten by weight, and a 2-mil thick cadmium foil located at a radius of 5 cm. A detailed response function for the new rem meter (dubbed the Model 652) was derived over the neutron energy range from thermal to 20 MeV using Monte Carlo transport techniques. Compared with the standard Eberline NRD rem mete, the new design is about 1.5 kg lighter, and is 28% more sensitive per unit dose of Cf-252. It is shown that for a large variety of standard and operational neutron spectra, the model 652 rem meter provides a response accuracy of {plus_minus}15%.

Olsher, R.H.; Hsu, Hsiao-Hua

1993-11-01

368

Equivalent source mapping of lunar magnetic field  

NASA Astrophysics Data System (ADS)

JAXA (Japan Aerospace Exploration Agency) shall launch the SELENE (SELenological and ENgineering Explorer) spacecraft this autumn. Amongst many instruments, it has a magnetometer (LMAG: Lunar MAGnetomter) which will measure the magnetic field on the orbit around the Moon. The nominal orbit of the SELENE is about 100km in altitudes for 1 year observation. Although the extended mission is still not determined, LMAG team is requesting a low altitude (less than 50km) observation, if the remaining fuel allows. We are preparing data processing software for the mission. Here, we report an objective scheme for mapping the lunar crustal magnetic field from the orbital measurement data of unequal altitudes. In this study, the magnetic field is restored by solving a linear inverse-problem determining the sources distributed on the lunar surface to satisfy the observational data, which is known as the equivalent source method. Our scheme has three features improving the method: First, the source calculation is performed simultaneously with detrending. Second, magnetic charges (magnetic monopoles) are used as the equivalent sources. It reduces the density of the sources for the same smoothness in produced field, comparing to the dipole sauces. Third, the number of sources is taken large enough to avoid the problem of configuration of the sources, instead the damped least square assuming the strength of each charge is similar to the next one, and the smoothness factor is determined by minimizing Akaike's Bayesian Information Criterion (ABIC). It guarantees the objectivity of the calculation, in other words, there is no adjustable parameter which may depend of the researcher dealing the data analyses. For testing the scheme, we apply this method to the Lunar Prospector magnetometer data, and provide magnetic field map in the region centered at several regions of strong crustal field including the Reiner Gamma anomaly. The stability of the method and the resolution of the anomaly map are found to be satisfactory.

Toyoshima, M.; Shibuya, H.

2007-12-01

369

Dielectrophoretic trapping without embedded electrodes  

NASA Astrophysics Data System (ADS)

We observe dielectrophoretic effects in mixed electrokinetic and dielectrophoretic flows in uniform arrays of posts. Above a threshold applied electric field, flowing filaments of concentrated and rarefied particles appear in the flow. Above a higher-threshold applied field, zones of highly concentrated, immobilized particles appear. At the lower and higher thresholds, dielectrophoresis apparently begins to dominate diffusion and advection/electrokinesis, respectively. The patterns of filaments and trapped zones depend dramatically on the angle of the array with respect to the mean applied electric field and the shape of the posts in the array.

Cummings, Eric B.; Singh, Anup K.

2000-08-01

370

Trapping leidenfrost drops with crenelations.  

PubMed

Drops placed on very hot solids levitate on a cushion of their own vapor, as discovered by Leidenfrost. This confers to these drops a remarkable mobility, which makes problematic their control and manipulation. Here we show how crenelated surfaces can be used to increase the friction of Leidenfrost drops by a factor on the order of 100, making them decelerate and be trapped on centimetric distances instead of the usual metric ones. We measure and characterize the friction force as a function of the design of the crenelations. PMID:22026676

Dupeux, Guillaume; Le Merrer, Marie; Clanet, Christophe; Quéré, David

2011-09-01

371

Cosmological apparent and trapping horizons  

NASA Astrophysics Data System (ADS)

The dynamics of particle, event, and apparent horizons in Friedmann-Lemaitre-Robertson-Walker space are discussed. The apparent horizon is trapping when the Ricci curvature is positive. This simple criterion coincides with the condition for the Kodama-Hayward apparent horizon temperature to be positive and also discriminates between the timelike and spacelike character of the apparent horizon. We discuss also the entropy of apparent cosmological horizons in extended theories of gravity and we use the generalized 2nd law to discard an exact solution of Brans-Dicke gravity as unphysical.

Faraoni, Valerio

2011-07-01

372

Stump appendicitis. A diagnostic trap.  

PubMed

Stump appendicitis is an underestimated condition and a diagnostic trap that few surgeons think about when faced against localized pain in the lower-right abdomen. Misdiagnosis and therefore delay of the appropriate treatment results in increased morbidity. We report the case of a patient who presented a 7-day history of right iliac fossa abdominal pain. She had undergone open appendectomy in childhood. Stump appendicitis was not diagnosed immediately despite imaging (CT and MRI) and exploratory laparoscopy. In conclusion, surgeons and gastroenterologists need a heightened awareness of the possibility of stump appendicitis. PMID:23414916

Lupinacci, Renato M; Bouchet-Doumenq, Cécile; Salepcioglu, Harika; Egels, Sophie; Menegaux, Fabrice; Trésallet, Christophe

2014-04-01

373

Cross-domain interference costs during concurrent verbal and spatial serial memory tasks are asymmetric.  

PubMed

Some evidence suggests that memory for serial order is domain-general. Evidence also points to asymmetries in interference between verbal and visual-spatial tasks. We confirm that concurrently remembering verbal and spatial serial lists provokes substantial interference compared with remembering a single list, but we further investigate the impact of this interference throughout the serial position curve, where asymmetries are indeed apparent. A concurrent verbal order memory task affects spatial memory performance throughout the serial positions of the list, but performing a spatial order task affects memory for the verbal serial list only for early list items; in the verbal task only, the final items are unaffected by a concurrent task. Adding suffixes eliminates this asymmetry, resulting in impairment throughout the list for both tasks. These results suggest that domain-general working memory resources may be supplemented with resources specific to the verbal domain, but perhaps not with equivalent spatial resources. PMID:22512308

Morey, Candice C; Mall, Jonathan T

2012-01-01

374

Equivalence between free quantum particles and those in harmonic potentials and its application to instantaneous changes  

NASA Astrophysics Data System (ADS)

In quantum physics the free particle and the harmonically trapped particle are arguably the most important systems a physicist needs to know about. It is little known that, mathematically, they are one and the same. This knowledge helps us to understand either from the viewpoint of the other. Here we show that all general time-dependent solutions of the free-particle Schrödinger equation can be mapped to solutions of the Schrödinger equation for harmonic potentials, both the trapping oscillator and the inverted "oscillator". This map is fully invertible and therefore induces an isomorphism between both types of system, they are equivalent. A composition of the map and its inverse allows us to map from one harmonic oscillator to another with a different spring constant and different center position. The map is independent of the state of the system, consisting only of a coordinate transformation and multiplication by a form factor, and can be chosen such that the state is identical in both systems at one point in time. This transition point in time can be chosen freely, the wave function of the particle evolving in time in one system before the transition point can therefore be linked up smoothly with the wave function for the other system and its future evolution after the transition point. Such a cut-and-paste procedure allows us to describe the instantaneous changes of the environment a particle finds itself in. Transitions from free to trapped systems, between harmonic traps of different spring constants or center positions, or, from harmonic binding to repulsive harmonic potentials are straightforwardly modelled. This includes some time-dependent harmonic potentials. The mappings introduced here are computationally more efficient than either state-projection or harmonic oscillator propagator techniques conventionally employed when describing instantaneous (non-adiabatic) changes of a quantum particle's environment.

Steuernagel, Ole

2014-06-01

375

Trap loss in a dual-species Rb-Ar* magneto-optical trap  

SciTech Connect

We have investigated trap loss in a dual-species magneto-optical trap (MOT) comprised of {sup 85}Rb and metastable {sup 40}Ar. We measure the trap loss rate coefficients for each species due to the presence of the other as a function of trap light intensity. We clearly identify both Penning ionization of Rb by Ar* and associative ionization to form the molecular ion RbAr{sup +} as two of the trap loss channels. We have also measured the trap loss rate coefficient for the Ar* MOT alone and observe production of Ar{sup +} and Ar{sub 2}{sup +} ions.

Busch, H. C.; Shaffer, M. K.; Ahmed, E. M.; Sukenik, C. I. [Department of Physics, Old Dominion University, Norfolk, Virginia 23529 (United States)

2006-02-15

376

Survey of manual handling tasks  

Microsoft Academic Search

The purpose of this study was to tabulate and summarize the characteristics of typical manual handling tasks (lifting, lowering, pushing, pulling and carrying) performed at 2442 industrial locations in the United States. Analyses of manual handling tasks during a 13yr period were collected and reviewed at the Liberty Mutual Research Center for Safety and Health. The components of each manual

Vincent M Ciriello; Stover H Snook

1999-01-01

377

Electricity Series. Duty Task List.  

ERIC Educational Resources Information Center

This task list is intended for use in planning and/or evaluating a competency-based course in electricity. The guide outlines the tasks entailed in 10 different duties typically required of employees in the following occupations: residential electrician apprentice, material handler/supply clerk, maintenance electrician apprentice,…

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

378

Printing Series. Duty Task List.  

ERIC Educational Resources Information Center

This document contains the occupational duty/task lists for 10 occupations in the printing series. Each occupation is divided into a number of duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide space for…

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

379

CHAPTER 43: COGNITIVE TASK ANALYSIS  

Microsoft Academic Search

This chapter presents an overview of the current state of Cognitive Task Analysis (CTA) in research and practice. CTA uses a variety of interview and observation strategies to capture a description of the explicit and implicit knowledge that experts use to perform complex tasks. The captured knowledge is most often transferred to training or the development of expert systems. The

Richard E. Clark; David F. Feldon; Kenneth A. Yates; Sean Early

380

Trapping cold atoms with ultrafast laser pulses  

NASA Astrophysics Data System (ADS)

The aim of this research is to pave the way for making a trap for cold neutral atoms based on the force generated by pulses of a mode-locked laser. As an onset towards such a trap we decided to use a far-off-resonance trap (FORT) loaded with cold rubidium atoms from a magneto-optical trap (MOT). Our FORT setup consists of a titanium-sapphire laser that can operate both in continuous wave mode and in mode-locked mode. Our MOT setup uses a magnetic field gradient, and two diode lasers whose frequency is locked very accurately to the atomic transition using polarisation spectroscopy. Since the measurements we do require very precise timing of the order of less than one millisecond between the various phases of the experiment, a time-sequencing program was developed. Using this sophisticated setup, several characteristics of FORTs made with continuous and pulsed lasers were analysed. For example, we have investigated the loading behaviour of the traps and found that under general circumstances there is no significant difference. However, under special conditions it is possible to load more atoms into a pulsed trap. The lifetime of the number of atoms in the trap shows no dependence on the power of the trap laser in the continuous case. For the pulsed trap, however, the increased scattering due to the high peak intensities of the pulses does limit the achievable lifetimes. Moreover, due to the presence of a large number of photoassociation lines, i.e. lines were loosely bound molecules are formed by the interaction of two atoms an a photon, the two-particle losses depend heavily on the wavelength of the trap laser. Furthermore we have done measurements of the temperature of the trapped atoms, which revealed that the temperature is a constant fraction of the trap depth. We also looked at the effects of parametric excitation of the atoms in the FORT. The anharmonicity of the trap formed by the titanium-sapphire laser results in interesting physics, including a change in the average temperature of the atoms, depending on the modulation frequency. We also investigated the trapping behaviour of the FORT at low pulse repetition rates by switching the laser intensity on and off on a kHz scale. We investigated the dependence of the number of atoms on the polarisation of the FORT laser light, both for continuous and pulsed traps. Atoms can be trapped at elliptical polarisations as well, although the number of trapped atoms is less. As the laser is detuned further to the red of the rubidium D line, this effect becomes less and less pronounced, as predicted by our model.

Karssen, L. C.

2008-10-01

381

49 CFR 396.23 - Equivalent to periodic inspection.  

Code of Federal Regulations, 2010 CFR

... false Equivalent to periodic inspection. 396.23 Section 396.23...MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE § 396.23 Equivalent to periodic inspection. (a) A motor carrier or...

2010-10-01

382

30 CFR 71.206 - Approved sampling devices; equivalent concentrations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Approved sampling devices; equivalent concentrations. 71...SURFACE WORK AREAS OF UNDERGROUND COAL MINES Sampling Procedures § 71.206 Approved sampling devices; equivalent concentrations....

2013-07-01

383

30 CFR 70.206 - Approved sampling devices; equivalent concentrations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Approved sampling devices; equivalent concentrations. 70...HEALTH STANDARDS-UNDERGROUND COAL MINES Sampling Procedures § 70.206 Approved sampling devices; equivalent...

2013-07-01

384

30 CFR 90.206 - Approved sampling devices; equivalent concentrations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Approved sampling devices; equivalent concentrations. 90...EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.206 Approved sampling devices; equivalent concentrations....

2013-07-01

385

Task Attention Facilitates Learning of Task-Irrelevant Stimuli  

PubMed Central

Attention plays a fundamental role in visual learning and memory. One highly established principle of visual attention is that the harder a central task is, the more attentional resources are used to perform the task and the smaller amount of attention is allocated to peripheral processing because of limited attention capacity. Here we show that this principle holds true in a dual-task setting but not in a paradigm of task-irrelevant perceptual learning. In Experiment 1, eight participants were asked to identify either bright or dim number targets at the screen center and to remember concurrently presented scene backgrounds. Their recognition performances for scenes paired with dim/hard targets were worse than those for scenes paired with bright/easy targets. In Experiment 2, eight participants were asked to identify either bright or dim letter targets at the screen center while a task-irrelevant coherent motion was concurrently presented in the background. After five days of training on letter identification, participants improved their motion sensitivity to the direction paired with hard/dim targets improved but not to the direction paired with easy/bright targets. Taken together, these results suggest that task-irrelevant stimuli are not subject to the attentional control mechanisms that task-relevant stimuli abide.

Huang, Tsung-Ren; Watanabe, Takeo

2012-01-01

386

All steam traps aren`t equal  

SciTech Connect

Steam traps are automatic valves that sense the difference between steam, air, condensate, and noncondensate gases such as CO{sub 2}. Their objective is to purge air, condensate, and other noncondensate gases and trap steam in the system where it belongs. A properly working trap should never let steam escape. Though the requirements for steam traps are simple, even the most experienced plant engineers and maintenance personnel have trouble in their selection and care. This fact is not surprising when a typical plant using a range of steam pressures can easily have in excess of 100 different steam traps to consider in terms of type, pressure rating, capacity, and manufacturer. There are five major types of steam traps in common use today: inverted bucket, float and thermostatic (F and T), thermodynamic, bimetallic, and thermostatic. Each is described.

Picut, R. [Watson McDaniel Co., Norristown, PA (United States)

1996-09-01

387

Tube length-assisted optimized aerosol trapping  

NASA Astrophysics Data System (ADS)

Trapping a single aerosol using optical tweezers could be of great importance for environmental sciences. Though a single nanoparticle as small as 10 nm is successfully trapped in aqueous media using optical tweezers, due to spherical aberration only large clusters of nanoparticles were stably trapped in air. In this paper we provide our theoretical and experimental results on optimized trapping of aerosols as small as 400 nm in radius by the introduction of an extra spherical aberration source in order to minimize the total spherical aberration of the system. Our method allows for trapping of high refractive index particles such as polystyrene beads in air. It also provides considerably large trappable depth range which endows in-depth trapping. Our theoretical and experimental results are in very good agreement.

Taheri, S. Mohammad-Reza; Sadeghi, Mohammad; Madadi, Ebrahim; S. Reihani, S. Nader

2014-10-01

388

The new ClusterTrap setup  

NASA Astrophysics Data System (ADS)

ClusterTrap has been designed to investigate properties of atomic clusters in the gas phase with particular emphasis on the dependence on the cluster size and charge state. The combination of cluster source, Penning trap and time-of-flight mass spectrometry allows a variety of experimental schemes including collision-induced dissociation, photo-dissociation, further ionization by electron impact, and electron attachment. Due to the storage capability of the trap extended-delay reaction experiments can be performed. Several recent modifications have resulted in an improved setup. In particular, an electrostatic quadrupole deflector allows the coupling of several sources or detectors to the Penning trap. Furthermore, a linear radio-frequency quadrupole trap has been added for accumulation and ion bunching and by switching the potential of a drift tube the kinetic energy of the cluster ions can be adjusted on their way towards or from the Penning trap. Recently, experiments on multiply negatively charged clusters have been resumed.

Martinez, F.; Marx, G.; Schweikhard, L.; Vass, A.; Ziegler, F.

2011-07-01

389

Trapping Rydberg Atoms in an Optical Lattice  

SciTech Connect

Rubidium Rydberg atoms are laser excited and subsequently trapped in a one-dimensional optical lattice (wavelength 1064 nm). Efficient trapping is achieved by a lattice inversion immediately after laser excitation using an electro-optic technique. The trapping efficiency is probed via analysis of the trap-induced shift of the two-photon microwave transition 50S{yields}51S. The inversion technique allows us to reach a trapping efficiency of 90%. The dependence of the efficiency on the timing of the lattice inversion and on the trap laser power is studied. The dwell time of 50D{sub 5/2} Rydberg atoms in the lattice is analyzed using lattice-induced photoionization.

Anderson, S. E.; Younge, K. C.; Raithel, G. [FOCUS Center, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-12-23

390

Orientation of Culex mosquitoes to carbon dioxide-baited traps: flight manoeuvres and trapping efficiency.  

PubMed

Females of Culex quinquefasciatus Say and Culex tarsalis Coquillet (Diptera: Culicidae) in the host-seeking stage were released and video recorded in three dimensions in a large field wind tunnel as they flew to four kinds of CO2-baited mosquito traps. The trapping efficiency (number of mosquitoes approaching compared to the number caught) was determined for each trap type. The Encephalitis Virus Surveillance (EVS), Mosquito Magnet Freedom (MMF) and Mosquito Magnet Liberty (MML) traps captured only 13-16% of approaching Cx. quinquefasciatus females, whereas the Mosquito Magnet-X (MMX) trap captured 58%. Similar results were obtained for Cx. tarsalis. Orientation behaviour and flight parameters of mosquitoes approaching the four traps were compared. Mosquitoes spent the most time orienting to the EVS trap. Flight speed decreased as mosquitoes entered the vicinity of each trap and a large portion of their time was spent within 30 cm downwind of the traps. Flights became highly tortuous downwind of the poorly performing traps and just upwind of the MMX trap. Differences between traps and possible explanations for the superior performance of the MMX trap are considered. PMID:16608486

Cooperband, M F; Cardé, R T

2006-03-01

391

Microwave Spectroscopy of Trapped Antihydrogen  

NASA Astrophysics Data System (ADS)

Theory predicts that, under CPTfootnotetextCharge conjugation, Parity inversion, and Time reversal. symmetry, the laws of physics make no distinction between matter and anti-matter. We have every reason to believe that equal amounts of both were produced in the early universe, following the Big Bang. However, our observable universe is overwhelmingly made up of matter. ALPHA is an international project located at CERN and involves ˜30 physicists from 15 different institutions. The primary goal of the collaboration is to investigate this gaping discrepancy between theoretical expectations and reality by precise comparison of matter and anti-matter, in particular hydrogen and antihydrogen. A critical milestone was reported in November 2010, the first-ever stable and reproducible magnetic confinement of neutral antihydrogen atoms. Shortly after, in June 2011, ALPHA announced the long-time (1000 s) trapping of antihydrogen, opening the door to precision spectroscopy. In March 2012, the first proof-of-principle spectroscopic measurement performed on trapped antihydrogen atoms using microwave radiationfootnotetextC. Amole, et al., (ALPHA collaboration), Nature 483, 439 (2012).. Detailed aspects of this measurement is presented in this talk.

Dehghani Ashkezari, Mohammad

2012-10-01

392

Extracellular DNA traps promote thrombosis  

PubMed Central

Neutrophil extracellular traps (NETs) are part of the innate immune response to infections. NETs are a meshwork of DNA fibers comprising histones and antimicrobial proteins. Microbes are immobilized in NETs and encounter a locally high and lethal concentration of effector proteins. Recent studies show that NETs are formed inside the vasculature in infections and noninfectious diseases. Here we report that NETs provide a heretofore unrecognized scaffold and stimulus for thrombus formation. NETs perfused with blood caused platelet adhesion, activation, and aggregation. DNase or the anticoagulant heparin dismantled the NET scaffold and prevented thrombus formation. Stimulation of platelets with purified histones was sufficient for aggregation. NETs recruited red blood cells, promoted fibrin deposition, and induced a red thrombus, such as that found in veins. Markers of extracellular DNA traps were detected in a thrombus and plasma of baboons subjected to deep vein thrombosis, an example of inflammation-enhanced thrombosis. Our observations indicate that NETs are a previously unrecognized link between inflammation and thrombosis and may further explain the epidemiological association of infection with thrombosis.

Fuchs, Tobias A.; Brill, Alexander; Duerschmied, Daniel; Schatzberg, Daphne; Monestier, Marc; Myers, Daniel D.; Wrobleski, Shirley K.; Wakefield, Thomas W.; Hartwig, John H.; Wagner, Denisa D.

2010-01-01

393

Economic and Politico-Economic Equivalence of Fiscal Policies  

Microsoft Academic Search

We extend “economic equivalence” results, like the Ricardian equivalence proposition, to the political sphere where policy is chosen sequentially. We derive conditions under which a policy regime (summarizing admissible policy choices in every period) and a state are “politico-economically equivalent” to another such pair, in the sense that both pairs give rise to the same equilibrium allocation. We apply the

Mart ´ õn Gonzalez-Eiras; Martin Gonzalez-Eiras

2012-01-01

394

The Assessment of Effective Dose Equivalent Using Personnel Dosimeters  

Microsoft Academic Search

From January 1994, U.S. nuclear plants must develop a technically rigorous approach for determining the effective dose equivalent for their work forces. This dissertation explains concepts associated with effective dose equivalent and describes how to assess effective dose equivalent by using conventional personnel dosimetry measurements. A Monte Carlo computer code, MCNP, was used to calculate photon transport through a model

Xie Xu

1994-01-01

395

Immuno–spin trapping of DNA radicals  

Microsoft Academic Search

The detection of DNA radicals by immuno–spin trapping (IST) is based on the trapping of radicals with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), forming stable nitrone adducts that are then detected using an anti-DMPO serum. DNA radicals are very reactive species, and because they are paramagnetic they have previously been detected only by electron spin resonance (ESR) with or without spin trapping, which

Sandra E Gomez Mejiba; Ronald P Mason; Dario C Ramirez

2006-01-01

396

Outer trapped surfaces are dense near MOTSs  

NASA Astrophysics Data System (ADS)

We show that any vacuum initial data set containing a marginally outer trapped surface S and satisfying a ‘no KIDs’ condition can be perturbed near S so that S becomes strictly outer trapped in the new vacuum initial data set. This, together with the results in Eichmair et al (2012), gives a precise sense in which generic initial data containing marginally outer trapped surfaces lead to geodesically incomplete spacetimes.

Chru?ciel, Piotr T.; Galloway, Gregory J.

2014-02-01

397

Novel designs for Penning ion traps  

Microsoft Academic Search

We present a number of alternative designs for Penning ion traps suitable for\\u000aquantum information processing (QIP) applications with atomic ions. The first\\u000atrap design is a simple array of long straight wires which allows easy optical\\u000aaccess. A prototype of this trap has been built to trap Ca+ and a simple\\u000aelectronic detection scheme has been employed to demonstrate

J. R. Castrejon-Pita; H. Ohadi; D. R. Crick; D. F. A. Winters; D. M. Segal; R. C. Thompson

2006-01-01

398

Inductive dressed ring traps for ultracold atoms  

NASA Astrophysics Data System (ADS)

We present two novel dressed inductive ring trap geometries, ideal for atom interferometry or studies of superfluidity and well-suited to utilization in atom chip architectures. The design permits ring radii currently only accessible via near-diffraction-limited optical traps, whilst retaining the ultra-smooth magnetic potential afforded by inductive traps. One geometry offers simple parallel implementation of multiple rings, whereas the other geometry permits axial beam-splitting of the torus suitable for whole-ring atom interferometry.

Vangeleyn, Matthieu; Garraway, Barry M.; Perrin, Hélène; Arnold, Aidan S.

2014-04-01

399

A critical review of sedimentation trap technique  

Microsoft Academic Search

The published literature on the use of sediment traps has been reviewed and used to validate the conclusions of a theoretical\\u000a analysis of the physical factors affecting the trapping of particles. Both practical and theoretical considerations lead us\\u000a to recommed that the ‘best’ sediment trap for use in limnology is a simple cylinder with a diameter of from 5 to

J. Bloesch; N. M. Burns

1980-01-01

400

Verbal self-reports of emergent relations in a stimulus equivalence procedure.  

PubMed Central

During a preliminary training phase, college students were taught to categorize each of their responses accurately in a conditional discrimination task as either correct or incorrect. Next, in the absence of self-reports, subjects acquired conditional discriminations (involving novel stimuli) prerequisite to the formation of two four-member equivalence classes. The self-report procedure was reinstated during probe sessions that tested for untrained relations indicative of equivalence class formation. Interspersed trials involving trained relations provided a positive control, and trials with no class-consistent comparison provided a negative control. Eight of 10 subjects demonstrated equivalence class formation; all accurately reported their performance on trained relations and on trials with no class-consistent comparison. Subjects also reported their performance on most untrained (emergent) relations accurately, but in several instances self-reports indicated failure or uncertainty despite nearly perfect emergent-relations performance. These inconsistencies add to a growing body of literature that suggests there are differences between individual types of emergent relations. We suggest that the present procedure may be helpful in understanding these differences and other equivalence-related effects.

Lane, S D; Critchfield, T S

1996-01-01

401

Learning an L1-regularized Gaussian Bayesian network in the equivalence class space.  

PubMed

Learning the structure of a graphical model from data is a common task in a wide range of practical applications. In this paper, we focus on Gaussian Bayesian networks, i.e., on continuous data and directed acyclic graphs with a joint probability density of all variables given by a Gaussian. We propose to work in an equivalence class search space, specifically using the k-greedy equivalence search algorithm. This, combined with regularization techniques to guide the structure search, can learn sparse networks close to the one that generated the data. We provide results on some synthetic networks and on modeling the gene network of the two biological pathways regulating the biosynthesis of isoprenoids for the Arabidopsis thaliana plant. PMID:20083459

Vidaurre, Diego; Bielza, Concha; Larrañaga, Pedro

2010-10-01

402

Tests of the weak equivalence principle  

NASA Astrophysics Data System (ADS)

The Einstein equivalence principle is the foundation for general relativity and all metric theories of gravity. Of its three tenets—the equality of acceleration of test bodies, or weak equivalence principle; the validity of Lorentz invariance in local freely falling frames; and the position invariance of local physical laws—the weak equivalence principle has played the most important role historically, and continues to be a focus of intense theoretical and experimental investigation. From the probably apocryphal 16th century demonstrations by Galileo at Pisa's leaning tower to the sensitive torsion-balance measurements of today (both pictured on the cover of this issue), this principle, dubbed WEP, has been crucial to the development of gravitation theory. The universality of the rate of acceleration of all types of matter in a gravitational field can be taken as evidence that gravitation is fundamentally determined by the geometry, or metric, of spacetime. Newton began his magnum opus 'The Principia' with a discussion of WEP and his experiments to verify it, while Einstein took WEP for granted in his construction of general relativity, never once referring to the epochal experiments by Baron Eötvös. The classic 1964 experiment of Roll, Krotkov and Dicke ushered in the modern era of high-precision tests, and the search for a 'fifth force' during the late 1980s (instigated, ironically, by purported anomalies in Eötvös's old data) caused the enterprise to pivot from pure tests of the foundation of GR to searches for new physics beyond the standard model of the non-gravitational interactions. Today, the next generation of experimental tests of WEP are being prepared for launch or are being developed, with the goal of reaching unprecedented levels of sensitivity, in search of signatures of interactions inspired by string theory, extra dimensions and other concepts from the world of high-energy physics. At the same time observations continue using lunar laser ranging and binary pulsar timing to test a stronger version of WEP, in order to verify whether gravitational mass/energy itself falls with the same acceleration as normal matter. This focus issue brings together a set of invited papers to explore the many aspects of testing WEP. An introductory article laying out the theoretical context is followed by articles on current laboratory experiments. Four articles describe the latest results from lunar laser ranging and binary pulsar timing, while two articles discuss progress toward testing the free fall of antihydrogen. The final four articles address future experiments to be carried out in space on orbiting or sub-orbital platforms. We hope that readers will take away from these articles both the centrality of this principle to gravitational physics and the rich and wide-ranging experimental activity that is being carried out to test it. C C Speake and C M WillGuest Editors

Speake, C. C.; Will, C. M.

2012-09-01

403

Non-destructive ion trap mass spectrometer and method  

DOEpatents

The invention relates to an ion trap mass spectrometer of the type having an ion trapping volume defined by spaced end caps and a ring electrode. The ion trap includes a small sensing electrode which senses characteristic motion of ions trapped in said trapping volume and provides an image current. Ions are excited into characteristic motion by application of an excitation pulse to the trapped ions. The invention also relates to a method of operating such an ion trap.

Frankevich, Vladimir E. (West Lafayette, IN); Soni, Manish H. (West Lafayette, IN); Nappi, Mario (West Lafayette, IN); Santini, Robert E. (West Lafayette, IN); Amy, Jonathan W. (West Lafayette, IN); Cooks, Robert G. (West Lafayette, IN)

1997-01-01

404

Laser induced fluorescence of trapped molecular ions  

SciTech Connect

An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references.

Grieman, F.J.

1979-10-01

405

Drug trapping and delivery for Alzheimer's diagnosis.  

PubMed

In this investigation, a new design based on a PANDA ring resonator as an optical trapping tool for tangle protein, molecular motor storage, and delivery is proposed. The optical vortices are generated and the trapping mechanism is controlled in the same way as the conventional optical tweezers. The trapping force is produced by a combination of the gradient field and scattering photons. The required molecular volume is trapped and moved dynamically within the molecular network. The tangle protein and molecular motor can be transported and delivered to the required destinations for Alzheimer's diagnosis by molecular buffer and bus network. PMID:22384850

Jalil, M A; Kamoldilok, Surachart; Saktioto, T; Ong, C T; Yupapin, Preecha P

2012-10-01

406

Generalized Dicke nonequilibrium dynamics in trapped ions.  

PubMed

We explore trapped ions as a setting to investigate nonequilibrium phases in a generalized Dicke model of dissipative spins coupled to phonon modes. We find a rich dynamical phase diagram including superradiantlike regimes, dynamical phase coexistence, and phonon-lasing behavior. A particular advantage of trapped ions is that these phases and transitions among them can be probed in situ through fluorescence. We demonstrate that the main physical insights are captured by a minimal model and consider an experimental realization with Ca+ ions trapped in a linear Paul trap with a dressing scheme to create effective two-level systems with a tunable dissipation rate. PMID:24484012

Genway, Sam; Li, Weibin; Ates, Cenap; Lanyon, Benjamin P; Lesanovsky, Igor

2014-01-17

407

Monolithic symmetric ion trap for quantum simulation  

NASA Astrophysics Data System (ADS)

We describe the novel design of a monolithic two-level ion trap that combines the flexibility and scalability of VLSI silicon microfabrication with the superior trapping characteristics of multi-level traps. Electrostatic simulations demonstrate that the trap has a deep trapping potential (1 eV for Yb+ ion) and radially symmetric RF confinement field. The trap has an angled through-chip slot which allows backside ion loading and through laser access while avoiding surface light scattering and dielectric charging. The geometrical trap features and dimensions are optimized for investigating ion chains with equal ion spacing. Control potentials have been derived to produce linear equally-spaced ion chains of up to 50 ions that can be used to perform simulations of quantum magnets. The potentials are optimized to give ion separations of 5 to 10 microns, micromotion compensation, and constant motional mode axes and frequencies along the chain. The trap is in fabrication at Georgia Tech using techniques similar to those developed for the planar ion traps.

Shaikh, Fayaz; Slusher, Richart

2011-06-01

408

s-wave pseudopotential for anisotropic traps  

SciTech Connect

Starting from two identical, interacting particles in an isotropic harmonic trap, we employ first-order perturbation theory to derive the effective s-wave pseudopotential operator for a weakly anisotropic trap. It is shown that such a confinement gives rise to a correction of the s-wave scattering length which is proportional to the square of the ratio of the bare scattering length and the oscillator length. The trap pseudopotential depends on the quantum number of the trapped state, and the effect of a weak anisotropy is dominated by its nearest neighbors. Some implications for experiments with cold bosons in tightly confining potentials are discussed briefly.

Pade, Jochen; Block, Martin; Holthaus, Martin [Institut fuer Physik, Carl von Ossietzky Universitaet, D-26111 Oldenburg (Germany)

2003-12-01

409

Generalized Dicke Nonequilibrium Dynamics in Trapped Ions  

NASA Astrophysics Data System (ADS)

We explore trapped ions as a setting to investigate nonequilibrium phases in a generalized Dicke model of dissipative spins coupled to phonon modes. We find a rich dynamical phase diagram including superradiantlike regimes, dynamical phase coexistence, and phonon-lasing behavior. A particular advantage of trapped ions is that these phases and transitions among them can be probed in situ through fluorescence. We demonstrate that the main physical insights are captured by a minimal model and consider an experimental realization with Ca+ ions trapped in a linear Paul trap with a dressing scheme to create effective two-level systems with a tunable dissipation rate.

Genway, Sam; Li, Weibin; Ates, Cenap; Lanyon, Benjamin P.; Lesanovsky, Igor

2014-01-01

410

"Tack" ion trap for efficient photon collection.  

NASA Astrophysics Data System (ADS)

Trapped, laser-cooled atoms and ions produce intense fluorescence of the order 10^7 -- 10^8 photons per second. Detection of this fluorescence enables the efficient measurement of the quantum state of qubit based on the trapped atoms. Thus, it is desirable to collect a large fraction of the (isotropically emitted) photons to make the detection faster and more reliable. Additionally, efficient fluorescence collection can improve the speed and fidelity of remote ion entanglement and quantum gates. Refractive and reflective optics, as well as optical cavities, and, recently, bare multimode optical fibers have all been used to collect the trapped ion fluorescence with up to 10% efficiency. Here we show a novel ion trap design that incorporates a high numerical aperture metallic spherical mirror as the integral part of the trap itself (the RF electrode) which enables up to 35% solid angle collection of trapped ion fluorescence. The movable central needle-shaped electrode of this "tack" trap allows precise placement of the ion at the focus of the spherical mirror. We also study the properties of the images formed by the spherical mirror and comment on possible methods for aberration correction. Owning to the simplicity of its design, this trap structure can be adapted for mircofabrication and integration into more complex trap architectures.

Chou, Chen-Kuan; Shu, Gang; Kurz, Nathan; Noel, Thomas; Wright, John; Blinov, Boris

2011-03-01

411

Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint  

SciTech Connect

Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

2011-04-01

412

Dynamic trapping and two-dimensional transport of swimming microorganisms using a rotating magnetic microrobot.  

PubMed

Manipulation of microorganisms with intrinsic motility is a challenging yet important task for many biological and biomedical applications. Currently, such a task has only been accomplished using optical tweezers, while at the risk of averse heating and photodamage of the biological samples. Here, we proposed a new micro-robotic approach for fluidic trapping and two-dimensional transportation of motile microorganisms near a solid surface in fluids. We demonstrated selective trapping and transportation of individual freely swimming multi-flagellated bacteria over a distance of 30 ?m (7.5 body length of the carrier) on a surface, using the rotational flows locally induced by a rotating magnetic microparticle. Only a weak uniform magnetic field (<3 mT) was applied to actuate the microparticle. The microparticle can translate on a glass substrate by rotating at a speed of up to 100 ?m s(-1), while providing a fluidic force of a few to tens of pico-Newtons. PMID:24663401

Ye, Zhou; Sitti, Metin

2014-07-01

413

Materials processing in space programs tasks. [NASA research tasks  

NASA Technical Reports Server (NTRS)

Active research tasks as of the end of fiscal year 1981 of the materials processing in space program, NASA Office of Space and Terrestrial Applications are summarized to provide an overview of the program scope for managers and scientists in industry, university, and government communities. The program, its history, strategy, and overall goal are described the organizational structures and people involved are identified and a list of recent publications is given for each research task. Four categories: Crystal Growth; Solidification of Metals, Alloys, and Composites; Fluids, Transports, and Chemical Processes, and Ultrahigh Vacuum and Containerless Processing Technologies are used to group the tasks. Some tasks are placed in more than one category to insure complete coverage of each category.

Pentecost, E.

1981-01-01

414

Interfaces and traps in pentacene field-effect transistor  

NASA Astrophysics Data System (ADS)

The equivalent circuit parameters for a pentacene organic field-effect transistor are determined from low frequency impedance measurements in the dark as well as under light illumination. The source-drain channel impedance parameters are obtained from Bode plot analysis and the deviations at low frequency are mainly due to the contact impedance. The charge accumulation at organic semiconductor-metal interface and dielectric-semiconductor interface is monitored from the response to light as an additional parameter to find out the contributions arising from photovoltaic and photoconductive effects. The shift in threshold voltage is due to the accumulation of photogenerated carriers under source-drain electrodes and at dielectric-semiconductor interface, and also this dominates the carrier transport. The charge carrier trapping at various interfaces and in the semiconductor is estimated from the dc and ac impedance measurements under illumination.

Sangeeth, C. S. Suchand; Stadler, P.; Schaur, S.; Sariciftci, N. S.; Menon, Reghu

2010-12-01

415

IGDS/TRAP Interface Program (ITIP). Software User Manual (SUM). [network flow diagrams for coal gasification studies  

NASA Technical Reports Server (NTRS)

This specification establishes the requirements, concepts, and preliminary design for a set of software known as the IGDS/TRAP Interface Program (ITIP). This software provides the capability to develop at an Interactive Graphics Design System (IGDS) design station process flow diagrams for use by the NASA Coal Gasification Task Team. In addition, ITIP will use the Data Management and Retrieval System (DMRS) to maintain a data base from which a properly formatted input file to the Time-Line and Resources Analysis Program (TRAP) can be extracted. This set of software will reside on the PDP-11/70 and will become the primary interface between the Coal Gasification Task Team and IGDS, DMRS, and TRAP. The user manual for the computer program is presented.

Jefferys, S.; Johnson, W.; Lewis, R.; Rich, R.

1981-01-01

416

Equivalence classes generated by sequence training.  

PubMed Central

In Experiment 1, 3, adult females were taught with verbal instructions and contingencies to select, in sequence, three arbitrary visual stimuli from an array of five stimuli. After four different sequences were taught, match-to-sample tests assessed emergent conditional relations among all stimuli that had been selected in the same order in the sequences. Subjects' performances indicated development of four stimulus classes, three based on ordinal position and one based on nonselection. Next, match-to-sample training established conditional relations between each of four novel figures and one member of each of the ordinal stimulus classes. Tests confirmed that the classes were equivalence classes, each expanded by one new member. In subsequent sequence tests, the new stimuli were selected in a sequence that was consistent with ordinal class membership. Experiment 2 replicated Experiment 1 with 2 different adult females, but the verbal instructions were omitted. Results were similar to Experiment 1, except that extensive review and retesting were required before expansion of the ordinal classes with the novel figures was observed.

Sigurdardottir, Z G; Green, G; Saunders, R R

1990-01-01

417

Concentration dependence of equivalent conductivity of polyelectrolyte.  

PubMed

Equivalent conductivity of aqueous solutions of alternating copolymer of iso-butyl vinyl ether and maleic acid, [poly(iso BVE-co-MA)] was studied, especially its polymer-concentration dependence. Various species of counterions such as quaternary ammoniumions (NMe4+, NEt4+, NPr4+, NBu4+) and divalent ions (Ca2+, Sr2+, Ba2+) were employed besides alkali metal ions. The applicability of Manning's conductivity theory was examined for the case of univalent counterions at various degrees of neutralization (beta). A major discrepancy against the theory was observed at beta = 1.0, while a comparatively good agreement was found at beta around 0.5. This suggests that the rod-like polyion model, which is the basis of the theory, is applicable near beta = 0.5, where polyions are most expanded. The low conductivities in the case of quaternary ammonium counterions suggested the ion-binding due to hydrophobic interaction with alkyl side chains. Molecular weight dependence was not appreciably observed near beta = 0.5 similarly to usual polyelectrolytes, but it appeared slightly at beta = 1.0. PMID:16997188

Miyamoto, S

1979-01-01

418

Enuresis: a functional equivalent of a fetish.  

PubMed

The split in the ego between consciousness and unconsciousness which sometimes eventuates in fetishism can also be clinically manifested in sleep disturbances, depersonalization, dejà vu and a variety of alterations in the sense of reality. It is suggested that this same split comprises the central dynamic mechanism in enuresis. The sleep disturbance which accompanies enuresis involves a confusion between waking and sleeping, sometimes taking the form of a dream that one is awake. Three patients(adult males) revealed in the course of their analyses that they suffered from childhood enuresis accompanied by a sleep disturbance. Milder forms of sleep disturbances persisted into adult life. In these analyses, certain perceptual distortions, difficulties in the sense of reality, and between fantasy and reality, confusions between waking and sleeping, could all be linked to the functional split between consciousness and unconsciousness and eventually to disavowal of the female genitals. The enuresis represented a functional equivalent of the fetish (and it may be that the urinary stream itself actually served as a fetish). Psychological test data from nine enuretic boys were examined as well. This material clearly demonstrated that these boys wished to deny the differences between males and females, that they suffered from sleep disturbances and that they confused reality and fantasy, sleeping and waking. The combined data suggest the existence of a functional split in the ego used in the service of defence, the product of a regressive fixation and a reinstatement of an archaic mode of thought. PMID:7440069

Calef, V; Weinshel, E M; Renik, O; Mayer, E L

1980-01-01

419

Dynamic equivalence between atomic and colloidal liquids  

NASA Astrophysics Data System (ADS)

We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient DS in a colloidal liquid, in the sense that the dynamic properties of the former, at times much longer than the mean free time, and properly scaled with DS, will be indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio DL/DS of the long-time to the short-time self-diffusion coefficients must then be the same for both an atomic and a colloidal system characterized by the same inter-particle interactions. This naturally extends to atomic fluids a well-known dynamic criterion for freezing of colloidal liquids (Löwen H. et al., Phys. Rev. Lett., 70 (1993) 1557). We corroborate these predictions by comparing molecular and Brownian dynamics simulations on the hard-sphere system and on other soft-sphere model systems, representative of the “hard-sphere”dynamic universality class.

López-Flores, Leticia; Mendoza-Méndez, Patricia; Sánchez-Díaz, Luis E.; Yeomans-Reyna, Laura L.; Vizcarra-Rendón, Alejandro; Pérez-Ángel, Gabriel; Chávez-Páez, Martín; Medina-Noyola, Magdaleno

2012-08-01

420

Exploiting Task-Level Parallelism Using pTask  

Microsoft Academic Search

This paper presents pTask— a system that allows users to automatically exploit dynamic task-level parallelism in sequential array-based C programs. The system employs compiler analysis to extract data usage information from the program, then uses this information at run-time to dynamically exploit concurrency and to enforce data-dependences. Experimental results using a prototype of the system show scaling performance and low

Tarek S. Abdelrahman; Sum Huynh

1996-01-01

421

Dose rate, dose-equivalent rate, and quality factor in SLS-1  

NASA Technical Reports Server (NTRS)

A tissue-equivalent proportional counter (TEPC) sensitive to the lineal energy range of 0.26-300 keV micrometer-1 was flown on STS-40 (39 degrees x 278 km x 296 km) inside the Spacelab. This instrument was previously flown on STS-31 but was modified to provide a finer resolution at lower lineal energies to better map the South Atlantic Anomaly (SAA) protons. The instrument was turned on 6 June 1991, and operated for 7470 min (124.5 h). The flight duration was characterized by a very large number of X-ray solar flares and enhanced magnetic field fluctuations; however, no significant dose from the solar particles was measured at the location of this instrument. The flight data can be separated into trapped and galactic cosmic radiation parts. The dose rate, dose-equivalent rate and quality factor for trapped radiation were 4.21 +/- 0.03 mrad day-1, 7.72 +/- 0.05 mrem day-1, and 1.83 +/- 0.1, respectively. The dose rate, dose-equivalent rate, and quality factor for galactic cosmic radiation were 5.34 +/- 0.03 mrad day-1, 14.63 +/- 0.06 mrem day-1, and 2.74 +/- 0.1, respectively. The overall quality factor for the flight was 2.38. The dose from the GCR is higher than from SAA protons because of the high inclination and low altitude of this flight. The AP8MAX model of the trapped radiation gives a dose rate of 2.43 mrad day-1 and a quality factor of 1.77. The CREME solar maximum model of galactic cosmic radiation gives a dose rate of 2.54 mrad day-1 and a quality factor of 2.91. Thus the AP8MAX model underestimates the dose by a factor of 1.8 whereas the CREME model leads to an underestimation of the dose by a factor of 2. A comparison of the LET spectra using the AP8MAX model and galactic cosmic radiation transport codes shows only a qualitative agreement.

Badhwar, G. D.; Braby, L. A.; Cucinotta, F. A.; Atwell, W.

1992-01-01

422

A restricted proof that the weak equivalence principle implies the Einstein equivalence principle  

NASA Technical Reports Server (NTRS)

Schiff has conjectured that the weak equivalence principle (WEP) implies the Einstein equivalence principle (EEP). A proof is presented of Schiff's conjecture, restricted to: (1) test bodies made of electromagnetically interacting point particles, that fall from rest in a static, spherically symmetric gravitational field; (2) theories of gravity within a certain broad class - a class that includes almost all complete relativistic theories that have been found in the literature, but with each theory truncated to contain only point particles plus electromagnetic and gravitational fields. The proof shows that every nonmentric theory in the class (every theory that violates EEP) must violate WEP. A formula is derived for the magnitude of the violation. It is shown that WEP is a powerful theoretical and experimental tool for constraining the manner in which gravity couples to electromagnetism in gravitation theories.

Lightman, A. P.; Lee, D. L.

1973-01-01

423

An analytic model of neutron ambient dose equivalent and equivalent dose for proton radiotherapy  

NASA Astrophysics Data System (ADS)

Stray neutrons generated in passively scattered proton therapy are of concern because they increase the risk that a patient will develop a second cancer. Several investigations characterized stray neutrons in proton therapy using experimental measurements and Monte Carlo simulations, but capabilities of analytical methods to predict neutron exposures are less well developed. The goal of this study was to develop a new analytical model to calculate neutron ambient dose equivalent in air and equivalent dose in phantom based on Monte Carlo modeling of a passively scattered proton therapy unit. The accuracy of the new analytical model is superior to a previous analytical model and comparable to the accuracy of typical Monte Carlo simulations and measurements. Predictions from the new analytical model agreed reasonably well with corresponding values predicted by a Monte Carlo code using an anthropomorphic phantom.

Zhang, Rui; Pérez-Andújar, Angélica; Fontenot, Jonas D.; Taddei, Phillip J.; Newhauser, Wayne D.

2010-12-01

424

A horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap.  

PubMed

Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- and cattle-keepers: reduced meat/milk production in cattle farms, horses cannot be ridden, decreased quality of hides due to biting scars. We show here that male and female tabanids can be caught by a novel, weather-proof liquid-filled black tray laid on the ground, because the strongly and horizontally polarized light reflected from the black liquid surface attracts water-seeking polarotactic tabanids. We performed field experiments to reveal the ideal elevation of the liquid trap and to compare the tabanid-capturing efficiency of three different traps: (1) the classic canopy trap, (2) the new polarization liquid trap, and (3) the combination of the two traps. In field tests, we showed that the combined trap captures 2.4-8.2 times more tabanids than the canopy trap alone. The reason for the larger efficiency of the combined trap is that it captures simultaneously the host-seeking female and the water-seeking male and female tabanids. We suggest supplementing the traditional canopy trap with the new liquid trap in order to enhance the tabanid-capturing efficiency. PMID:23806664

Egri, Á; Blahó, M; Száz, D; Kriska, G; Majer, J; Herczeg, T; Gyurkovszky, M; Farkas, R; Horváth, G

2013-12-01

425

Effects of a Foot Placement Constraint on Use of Motor Equivalence during Human Hopping  

PubMed Central

Humans can robustly locomote over complex terrains even while simultaneously attending to other tasks such as accurate foot placement on the ground. We investigated whether subjects would exploit motor redundancy across the joints of the leg to stabilize overall limb kinematics when presented with a hopping task that constrained foot placement position. Subjects hopped in place on one leg (2.2 Hz) while having to place their foot into one of three target sizes upon landing (0.250, 0.063, 0.010 m2). As takeoff and landing angles are critical to this task performance, we hypothesized smaller target sizes would increase the need to stabilize (i.e., make more consistent) the leg orientation through motor equivalent combinations of segment angles. As it was not critical to the targeting task, we hypothesized no changes for leg length stabilization across target size. With smaller target sizes, we saw total segment angle variance increase due to greater signal-dependent noise associated with an increased activation of leg extensor muscles (medial and lateral gastrocnemius, vastus medialis, vastus lateralis and rectus femoris). At smaller target sizes, more segment angle variance was aligned to kinematic deviations with the goal of maintaining leg orientation trajectory. We also observed a decrease in the variance structure for stabilizing leg length at the smallest target conditions. This trade-off effect is explained by the nearly orthogonal relationship between the two goal-equivalent manifolds for leg length vs. leg orientation stabilization. Our results suggest humans increasingly rely on kinematic redundancy in their legs to achieve robust, consistent locomotion when faced with novel conditions that constrain performance requirements. These principles may generalize to other human locomotor gaits and provide important insights into the control of the legs during human walking and running.

Auyang, Arick G.; Chang, Young-Hui

2013-01-01

426

Approaching the Trap-Free Limit in Organic Single-Crystal Field-Effect Transistors  

NASA Astrophysics Data System (ADS)

We present measurements of rubrene single-crystal field-effect transistors with textbooklike transfer characteristics, as one would expect for intrinsically trap-free semiconductor devices. Particularly, the high purity of the crystals and the defect-free interface to the gate dielectric are reflected in an unprecedentedly low subthreshold swing of 65 mV/decade, remarkably close to the fundamental limit of 58.5 mV/decade. From these measurements, we quantify the residual density of traps by a detailed analysis of the subthreshold regime, including a full numerical simulation. An exceedingly low trap density of Dbulk=1×1013 cm-3 eV-1 at an energy of approximately 0.62 eV is found. This result corresponds to one trap per eV in 108 rubrene molecules. The equivalent density of traps located at the interface (Dit=3×109 cm-2 eV-1) is as low as in the best crystalline Si/Si field-effect transistors. These results highlight the benefit of having van der Waals bonded semiconducting crystals without electronically active states due to broken bonds at the surface.

Blülle, Balthasar; Häusermann, Roger; Batlogg, Bertram

2014-04-01

427

The default mode network integrity in patients with Parkinson's disease is levodopa equivalent dose-dependent.  

PubMed

Disturbances in the default mode network (DMN) have been described in many neurological and psychiatric disorders including Parkinson's disease (PD). The DMN is characterized by basal activity that increases during rest or passive visual fixation and decreases ("deactivates") during cognitive tasks. The network is believed to be involved in cognitive processes. We examined the DMN in PD patients on dopaminergic medication with normal cognitive performance compared to age- and gender-matched healthy controls (HC) using fMRI and three methodological procedures: independent component analysis of resting-state data, analysis of deactivation during a complex visual scene-encoding task, and seed-based functional connectivity analysis. In the PD group, we also studied the effect of dopaminergic medication on the DMN integrity. We did not find any difference between the PD and HC groups in the DMN, but using the daily levodopa equivalent dose as a covariate, we observed an enhanced functional connectivity of the DMN in the posterior cingulate cortex and decreased activation in the left parahippocampal gyrus during the cognitive task. We conclude that dopaminergic therapy has a specific effect on both the DMN integrity and task-related brain activations in cognitively unimpaired PD patients, and these effects seem to be dose-dependent. PMID:22002597

Krajcovicova, L; Mikl, M; Marecek, R; Rektorova, Irena

2012-04-01

428

Mental Health Task Force Report.  

National Technical Information Service (NTIS)

Recommendations of a task force charged with examining conditions of mental health operatios in western Massachusetts are contained in this report. The greatest needs in the region were found to be crisis intervention, childrens' services, community-parti...

D. A. Allen

1974-01-01

429

Sample Items and Performance Tasks  

NSDL National Science Digital Library

This webpage contains sample items and performance tasks from the Smarter Balanced assessment system in mathematics as well as English LA/Literacy. They are intended to help teachers, administrators, and policymakers implementing the Common Core State Standards (CCSS) prepare for next-generation assessments and plan the required shifts in instruction. Sample items and tasks can be viewed by grade band (grades 3-5, 6-8, and high school) or content focus. They showcase the variety of item types, including technology-enhanced items and performance tasks, that will be included in the assessment system. A drop-down tab provides information on each item, including grade level, CCSS alignment, and a scoring rubric for performance tasks.

2012-01-01

430

Critique of the equivalent air altitude model.  

PubMed

The adverse effects of hypoxic hypoxia include acute mountain sickness (AMS), high altitude pulmonary edema, and high altitude cerebral edema. It has long been assumed that those manifestations are directly related to reduction in the inspired partial pressure of oxygen (P(I)O2). This assumption underlies the equivalent air altitude (EAA) model, which holds that combinations of barometric pressure (P(B)) and inspired fraction of O2 (F(I)O2) that produce the same P(I)O2 will result in identical physiological responses. However, a growing body of evidence seems to indicate that different combinations of P(B) and P(I)O2 may produce different responses to the same P(I)O2. To investigate this question with respect to AMS, we conducted a search of the literature using the terms hypobaric hypoxia, normobaric hypoxia, and hypobaric normoxia. The results suggest that the EAA model provides only an approximate description of isohypoxia, and that P(B) has an independent effect on hypoxia and AMS. A historical report from 1956 and 15 reports from 1983 to 2005 compare the same hypoxic P(I)O2 at different P(B) with respect to the development of hypoxia and AMS. These data provide evidence for an independent effect of P(B) on hypoxia and AMS, and thereby invalidate EAA as an ideal model of isohypoxia. Refinement of the EAA model is needed, in particular for applications to high altitude where supplemental O2 is inadequate to prevent hypoxic hypoxia. Adjustment through probabilistic statistical modeling to match the current limited experimental observations is one approach to a better isohypoxic model. PMID:18856188

Conkin, Johnny; Wessel, James H

2008-10-01

431

Novel light traps for studying ultracold atoms and molecules  

Microsoft Academic Search

We will begin with a brief review of the physics of cooling and trapping of atoms and molecules. We will then specialize the discussion to include two experiments in which unusual traps have been realized. In the first experiment, a pulsed optical dipole force trap, loaded from a magneto-optical trap (MOT) is used to confine atomic rubidium (Rb). The trap

Charles I. Sukenik

2005-01-01

432

Testing Tasks Management in Testing Cloud Environment  

Microsoft Academic Search

In testing Cloud environment testing tasks requested by different tenants have many uncertainties. The arriving time, deadline and the number of tasks are unknown in advance. Especially, the relationships between testing tasks and testing environments are very complex. How to efficiently manage these tasks is really a challenging problem. This paper studies the special features of testing tasks and presents

Lian Yu; Xiaohu Li; Zhongjie Li

2011-01-01

433

Extended Task Analysis Procedure (ETAP). User's Manual.  

National Technical Information Service (NTIS)

Extended Task Analysis Procedure (ETAP) is a 12 step process designed to analyze tasks that are primarily procedural in nature and tasks that are usually called 'Soft Skill' Tasks. This report is designed to assist the analyst to do an Extended Task Analy...

C. M. Reigeluth R. K. Branson R. Begland R. Tarr M. D. Merrill

1980-01-01

434

Compression of Antiproton Clouds for Antihydrogen Trapping  

SciTech Connect

Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.

Andresen, G. B.; Bowe, P. D.; Hangst, J. S. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Bertsche, W.; Butler, E.; Charlton, M.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der [Department of Physics, Swansea University, Swansea SA2 8PP (United Kingdom); Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S. [Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300 (United States); Cesar, C. L.; Lambo, R.; Silveira, D. M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972 (Brazil); Fujiwara, M. C.; Gill, D. R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada)] (and others)

2008-05-23

435

Collisions of trapped molecules with slow beams  

SciTech Connect

We present a theoretical study of molecular-trap loss induced by collisions with slow atomic beams based on an explicit analysis of collision kinematics in the laboratory frame and a rigorous quantum description of atom-molecule scattering in external fields. The theory is applied to elucidate the effects of nonuniform magnetic and optical trapping fields on low-temperature collisions of OH (J=3/2,M{sub J}=3/2,f) molecules with {sup 4}He atoms. Our calculations quantify the extent to which both elastic and inelastic cross sections are suppressed by external trapping fields, clarify the role of small-angle scattering in trap loss, and may benefit future experiments on collisional cooling of molecules in electromagnetic traps. The calculated cross sections for trap loss in {sup 4}He + OH collisions are consistent with recent experimental observations at low beam energies [B. C. Sawyer et al., Phys. Rev. Lett. 101, 203203 (2008)], demonstrating the importance of including the effects of nonuniform trapping fields in theoretical simulations of cold collision experiments with trapped molecules and slow atomic beams.

Tscherbul, T. V.; Dalgarno, A. [Harvard-MIT Center for Ultracold Atoms, Cambridge, Massachusetts 02138 (United States); Institute for Theoretical Atomic, Molecular, and Optical Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States); Pavlovic, Z. [Institute for Theoretical Atomic, Molecular, and Optical Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States); Sadeghpour, H. R. [Institute for Theoretical Atomic, Molecular, and Optical Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States); Cote, R. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

2010-08-15

436

Aluminum-Nitrogen Isoelectronic Trap in Silicon.  

National Technical Information Service (NTIS)

The A,B,C luminescence system from silicon is believed to originate with the radiative decay of an exciton bound to an isoelectronic trap. It was shown previously by Sauer, Weber, and Zulehner that nitrogen is one of the trap constituents. We present expe...

R. A. Modavis D. G. Hall

1990-01-01

437

An Experimental Analysis of Social Traps  

ERIC Educational Resources Information Center

Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. Alaboratory analog was devised to simulate conditions that produce social traps. The intent was to cause an immediate positive…

Brechner, Kevin C.

1977-01-01

438

Enhanced light collection from trapped ions  

Microsoft Academic Search

We present progress towards an ion trapping system capable of enhanced light collection based on nearby reflective optics [1--3]. This may not only boost the fidelity and speed of trapped ion qubit measurement, but may also greatly improve probabilistic entangling schemes relying on the collection and interference of single photons [4]. Two proposed schemes will be realized by placing a

J. D. Sterk; T. A. Manning; L. Luo; P. Maunz; S. Olmschenk; D. Hayes; D. Matsukevich; C. Monroe

2009-01-01

439

Experimental apparatus to test air trap valves  

Microsoft Academic Search

It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the

Y. de F. Lemos De Lucca; G. A. de Aquino; J. G. D. Filho

2010-01-01

440

Want to Know about Steam Traps.  

National Technical Information Service (NTIS)

Steam traps are a small but very important component in any steam distribution system. They represent a significant source of wasted energy when not properly used and maintained. Surveys have shown that on Navy shore facilities 30 to 35 percent of traps a...

M. Rocha

1997-01-01

441

Review of Orifice Plate Steam Traps.  

National Technical Information Service (NTIS)

This guide was prepared to serve as a foundation for making informed decisions about when orifice plate steam traps should be considered for use in new or existing steam systems. It presents background information about different types of steam traps and ...

C. B. Oland

2001-01-01

442

Applying steam traps to minimize energy losses  

Microsoft Academic Search

Different types of steam traps are considered which operate by sensing the difference between steam (a gas) and condensate (a liquid). The three basic physical properties of steam traps are introduced, and the operation of various types described. Using data for water flow and steam flow calculations for steam loss in 4 examples are made. A table showing the cost

Hilmer

1981-01-01

443

Charge trapping in interface doped MNOS structures  

NASA Astrophysics Data System (ADS)

Evaporated tungsten interface dopant, oxide-nitride interface and nitride bulk traps in MNOS structures were examined using charge centroid and thermally stimulated current (TSC) techniques. Trapping in dopant traps occurred at low injected charge levels. Above a 'saturation' level trapping occured in the nitride, and the charge centroid penetrated into the nitride. TSC measurements were made on MNS, MNOS, and interface doped MNOS devices. Analysis of TSC spectra yielded trap depths for the interface dopant and oxide-nitride interface of 1.71 - 1.86 and 0.70 - 1.34 eV respectively, and charge densities up to 6 x 10 to the 12th power/sq cm and 3x10 to the 13th power/sq cm respectively. A model of MNOS charging and discharging was developed. Electron charging is by Fowler-Nordheim (F-N) injection from the silicon into the oxide conduction band, trapping at the oxide-nitride interface and Poole-Frenkel (P-F) conduction in the nitride. Discharging occurs by: (1) F-N injection of holes from the silicon into the oxide valence band and recombination with trapped electrons at the oxide-nitride interface and the nitride, and (2) redistribution of trapped electrons toward the silicon via P-F conduction and F-N injection from the nitride into the silicon. Calculated write/erase and charge centroid characteristics were compared with measured data.

Sutton, W. G.

1981-07-01

444

Trapped radiation belts of Saturn - First look  

Microsoft Academic Search

Data on the magnetosphere of Saturn obtained with the trapped radiation detector package on board the Pioneer 11 spacecraft is reported. Radiation belt profiles determined by the trapped radiation detectors on Pioneer 10 and 11 indicate that Saturn's magnetosphere is intermediate in size between those of the earth and Jupiter, with particle intensities similar to those of the earth. The

W. Fillius; W. H. Ip; C. E. McIlwain

1980-01-01

445

Calibration of sound forces in acoustic traps  

Microsoft Academic Search

A two-dimensional or transverse acoustic trapping and its capability to noninvasively manipulate micrometersized particles with focused sound beams were experimentally demonstrated in our previous work. To apply this technique, as in optical tweezers, for studying mechanical properties of and interactions among biological particles such as cells, the trapping forces must be calibrated against known forces, i.e., viscous drag forces exerted

Jungwoo Lee; Changyang Lee; K. K. Shung

2010-01-01

446

Foam Prevention in Purge and Trap Analysis.  

National Technical Information Service (NTIS)

Volatile organics are often separated from water samples by bubbling an inert gas through the water and collecting the organics on a sorbent trap, a technique known as purge and trap. Unfortunately, during the analysis of many water samples, foam can clim...

M. D. Erickson M. K. Alsup P. A. Hyldburg

1981-01-01

447

Optical Peristaltic Pumping with Optical Traps.  

National Technical Information Service (NTIS)

A method of use for holographic optical traps or gradients in which repetitive cycling of a small number of appropriately designed arrays of traps are used for general and very complex manipulations of particles and volumes of matter. Material transport r...

D. G. Grier S. H. Behrens

2005-01-01

448

Adjustable multiple sub-Doppler traps in an asymmetric magneto-optical trap  

SciTech Connect

We have realized adjustable multiple sub-Doppler traps (SDT's) in a six-beam magneto-optical trap (MOT) under asymmetric trap conditions. In the simplest case, one obtains an array of three SDT's, one usual trap at the origin and two additional traps symmetrically but oppositely located at equal and controllable distances from the origin, in good agreement with theoretical calculations. The easily adjustable array of SDT's readily available in the asymmetric MOT may open the possibility of novel atom optics or quantum optics experiments such as atom interferometer or quantum information.

Heo, Myoung-sun; Kim, Kihwan; Lee, Ki-Hwan; Yum, Dahyun; Shin, Soyoung; Kim, Yonghee; Jhe, Wonho [Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea (Korea, Republic of); Noh, Heung-Ryoul [Department of Physics and Institute of Opto-Electronic Science and Technology, Chonnam National University, Gwangju 500-757, Korea (Korea, Republic of)

2007-02-15

449

Mapping two-dimension trapping potential of nanoparticles in an optical trap  

NASA Astrophysics Data System (ADS)

Combining confocal microscopy and optical tweezers, we map out the spatial distribution of the particle concentrations of quantum dots, fluorescent HIV pseudo virus particles and polystyrene nanospheres in an optical trap. By analyzing the Boltzmann distribution of local particle concentrations, we obtain the two-dimension single particle trapping potential profile at the center of the optical trap in the direction perpendicular to the beam propagation. We compare the trapping potential energies of pseudo HIV vesicles and same-sized polystyrene spheres. We also compare the trapping potential energy of polystyrene spheres of a focused Gaussian beam and two modes of cylindrical vector beams.

Fu, Jinxin; Hu, Yi; Zhou, Liangcheng; Lim, Min Yao; Goleb, Melissa; Zhan, Qiwen; Ou-Yang, H. Daniel

2013-06-01

450

Micro-fabricated stylus ion trap  

NASA Astrophysics Data System (ADS)

An electroformed, three-dimensional stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of proximate surfaces. The trap was microfabricated with the UV-LIGA technique to reduce the distance of the ion from the surface of interest. We detail the fabrication process used to produce a 150 ?m tall stylus trap with feature sizes of 40 ?m. We confined single, laser-cooled, 25Mg+ ions with lifetimes greater than 2 h above the stylus trap in an ultra-high-vacuum environment. After cooling a motional mode of the ion at 4 MHz close to its ground state ( = 0.34 +/- 0.07), the heating rate of the trap was measured with Raman sideband spectroscopy to be 387 +/- 15 quanta/s at an ion height of 62 ?m above the stylus electrodes.

Arrington, Christian L.; McKay, Kyle S.; Baca, Ehren D.; Coleman, Jonathan J.; Colombe, Yves; Finnegan, Patrick; Hite, Dustin A.; Hollowell, Andrew E.; Jördens, Robert; Jost, John D.; Leibfried, Dietrich; Rowen, Adam M.; Warring, Ulrich; Weides, Martin; Wilson, Andrew C.; Wineland, David J.; Pappas, David P.

2013-08-01

451

Magneto-optical trap for thulium atoms  

SciTech Connect

Thulium atoms are trapped in a magneto-optical trap using a strong transition at 410 nm with a small branching ratio. We trap up to 7x10{sup 4} atoms at a temperature of 0.8(2) mK after deceleration in a 40-cm-long Zeeman slower. Optical leaks from the cooling cycle influence the lifetime of atoms in the magneto-optical trap which varies between 0.3 and 1.5 s in our experiments. The lower limit for the leaking rate from the upper cooling level is measured to be 22(6) s{sup -1}. The repumping laser transferring the atomic population out of the F=3 hyperfine ground-state sublevel gives a 30% increase for the lifetime and the number of atoms in the trap.

Sukachev, D.; Sokolov, A.; Chebakov, K.; Akimov, A.; Kanorsky, S.; Kolachevsky, N.; Sorokin, V. [P.N. Lebedev Physical Institute, Leninsky Prospekt 53, 119991 Moscow (Russian Federation)

2010-07-15

452

A dynamical model for the Utricularia trap.  

PubMed

We propose a model that captures the dynamics of a carnivorous plant, Utricularia inflata. This plant possesses tiny traps for capturing small aquatic animals. Glands pump water out of the trap, yielding a negative pressure difference between the plant and its surroundings. The trap door is set into a meta-stable state and opens quickly as an extra pressure is generated by the displacement of a potential prey. As the door opens, the pressure difference sucks the animal into the trap. We write an ODE model that captures all the physics at play. We show that the dynamics of the plant is quite similar to neuronal dynamics and we analyse the effect of a white noise on the dynamics of the trap. PMID:22859569

Llorens, Coraline; Argentina, Médéric; Bouret, Yann; Marmottant, Philippe; Vincent, Olivier

2012-11-01

453

A dynamical model for the Utricularia trap  

PubMed Central

We propose a model that captures the dynamics of a carnivorous plant, Utricularia inflata. This plant possesses tiny traps for capturing small aquatic animals. Glands pump water out of the trap, yielding a negative pressure difference between the plant and its surroundings. The trap door is set into a meta-stable state and opens quickly as an extra pressure is generated by the displacement of a potential prey. As the door opens, the pressure difference sucks the animal into the trap. We write an ODE model that captures all the physics at play. We show that the dynamics of the plant is quite similar to neuronal dynamics and we analyse the effect of a white noise on the dynamics of the trap.

Llorens, Coraline; Argentina, Mederic; Bouret, Yann; Marmottant, Philippe; Vincent, Olivier

2012-01-01

454

Trapping atoms using nanoscale quantum vacuum forces  

PubMed Central

Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here we theoretically show that it is possible to tailor the vacuum forces themselves to provide strong trapping potentials. Our proposed trapping scheme takes advantage of the attractive ground-state potential and adiabatic dressing with an excited state whose potential is engineered to be resonantly enhanced and repulsive. This procedure yields a strong metastable trap, with the fraction of excited-state population scaling inversely with the quality factor of the resonance of the dielectric structure. We analyse realistic limitations to the trap lifetime and discuss possible applications that might emerge from the large trap depths and nanoscale confinement.

Chang, D. E.; Sinha, K.; Taylor, J. M.; Kimble, H. J.

2014-01-01

455

Trapping in dendrimers and regular hyperbranched polymers  

NASA Astrophysics Data System (ADS)

Dendrimers and regular hyperbranched polymers are two classic families of macromolecules, which can be modeled by Cayley trees and Vicsek fractals, respectively. In this paper, we study the trapping problem in Cayley trees and Vicsek fractals with different underlying geometries, focusing on a particular case with a perfect trap located at the central node. For both networks, we derive the exact analytic formulas in terms of the network size for the average trapping time (ATT)--the average of node-to-trap mean first-passage time over the whole networks. The obtained closed-form solutions show that for both Cayley trees and Vicsek fractals, the ATT display quite different scalings with various system sizes, which implies that the underlying structure plays a key role on the efficiency of trapping in polymer networks. Moreover, the dissimilar scalings of ATT may allow to differentiate readily between dendrimers and hyperbranched polymers.

Wu, Bin; Lin, Yuan; Zhang, Zhongzhi; Chen, Guanrong

2012-07-01

456

GAMMASPHERE: Correction technique for detector charge trapping  

SciTech Connect

GAMMASPHERE uses 110 very large germanium detectors. Such detectors exhibit charge trapping effects on energy resolution initially due to a native electron trap that is present in virtually all germanium. Furthermore, radiation damage is a serious problem in GAMMASPHERE experiments, producing hole traps that degrade resolution and eventually require annealing to restore the original performance. The technique discussed here uses the current pulse shape from a detector to develop a parameter related to the radius of the largest interaction in the ``track`` of a gamma ray in the detector. Since the charge trapping loss in a signal can be related to the distance carriers travel, the ``radius`` parameter can be used by software to apply a trap correction to the signal.

Goulding, F.S.; Landis, D.A.

1993-11-01

457

Ion Trap Networking:. Cold, Fast, and Small  

NASA Astrophysics Data System (ADS)

A large-scale ion trap quantum computer will require low-noise entanglement schemes and methods for networking ions between different regions. We report work on both fronts, with the entanglement of two trapped cadmium ions following a phase-insensitive Molmer-Sorensen quantum gate, the entanglement between a single ion and a single photon, and the development of advanced ion traps at the micrometer scale, including the first ion trap integrated on a semiconductor chip. We additionally report progress on the interaction of ultrafast resonant laser pulses with cold trapped ions. This includes fast Rabi oscillations on optical S-P transitions and broadband laser cooling, where the pulse laser bandwidth is much larger than the atomic linewidth. With these fast laser pulses, we also have developed a new method for precision measurement of excited state lifetimes.

Moehring, D. L.; Acton, M.; Blinov, B. B.; Brickman, K.-A.; Deslauriers, L.; Haljan, P. C.; Hensinger, W. K.; Hucul, D.; Kohn, R. N.; Lee, P. J.; Madsen, M. J.; Maunz, P.; Olmschenk, S.; Stick, D.; Yeo, M.; Monroe, C.; Rabchuk, J. A.

2005-12-01

458

Quality of reporting of clinical non-inferiority and equivalence randomised trials - update and extension  

PubMed Central

Background Non-inferiority and equivalence trials require tailored methodology and therefore adequate conduct and reporting is an ambitious task. The aim of our review was to assess whether the criteria recommended by the CONSORT extension were followed. Methods We searched the Medline database and the Cochrane Central Register for reports of randomised non-inferiority and equivalence trials published in English language. We excluded reports on bioequivalence studies, reports targeting on other than the main results of a trial, and articles of which the full-text version was not available. In total, we identified 209 reports (167 non-inferiority, 42 equivalence trials) and assessed the reporting and methodological quality using abstracted items of the CONSORT extension. Results Half of the articles did not report on the method of randomisation and only a third of the trials were reported to use blinding. The non-inferiority or equivalence margin was defined in most reports (94%), but was justified only for a quarter of the trials. Sample size calculation was reported for a proportion of 90%, but the margin was taken into account in only 78% of the trials reported. Both intention-to-treat and per-protocol analysis were presented in less than half of the reports. When reporting the results, a confidence interval was given for 85% trials. A proportion of 21% of the reports presented a conclusion that was wrong or incomprehensible. Overall, we found a substantial lack of quality in reporting and conduct. The need to improve also applied to aspects generally recommended for randomised trials. The quality was partly better in high-impact journals as compared to others. Conclusions There are still important deficiencies in the reporting on the methodological approach as well as on results and interpretation even in high-impact journals. It seems to take more than guidelines to improve conduct and reporting of non-inferiority and equivalence trials.

2012-01-01

459

Measurement of the trapping efficiency of an elliptical optical trap with rigid and elastic objects.  

PubMed

Optical tweezers and their various modifications offer a sophisticated way to perform noncontact cell manipulation. In this paper, we quantify forces existing in an elliptical trap formed by two cylindrical lenses and compare the results with a point optical trap case. The trapping efficiency of point and elliptical traps was analyzed by measuring the Q values of both traps. Polystyrene microspheres and red blood cells (RBCs) were used as samples. Stretching of the RBC was taken into account in the Q value measurements. Although the Q value of a point optical trap is larger than that of an elliptical trap when measured for a single RBC, we can manipulate the orientation of an RBC in a point trap with the elliptical trap and can also trap several RBCs simultaneously in the elliptical trap far from the cuvette surfaces by using a long-working-distance water immersion objective. This opens new possibilities for studying light-matter interactions at the cellular level. PMID:22885584

Kauppila, Antti; Kinnunen, Matti; Karmenyan, Artashes; Myllylä, Risto

2012-08-10

460

The habitats exploited and the species trapped in a Caribbean island trap fishery  

USGS Publications Warehouse

We visually observed fish traps in situ to identify the habitats exploited by the U.S. Virgin Islands fishery and to document species composition and abundance in traps by habitat. Fishers set more traps in algal plains than in any other habitat around St. John. Coral reefs, traditionally targeted by fishers, accounted for only 16% of traps. Traps in algal plain contained the highest number of fishes per trap and the greatest numbers of preferred food species. Traps on coral reefs contained the most species, 41 of the 59 taxa observed in the study. Acanthurus coeruleus was the most abundant species and Acanthuridae the most abundant family observed in traps. Piscivore numbers were low and few serranids were observed. Traps in algal plain contained the most fishes as a result of: ecological changes such as shifts in habitat use, mobility of species and degradation of nearshore habitat (fishery independent); and, catchability of fishes and long-term heavy fishing pressure (fishery dependent). The low number of serranids per trap, dominance of the piscivore guild by a small benthic predator, Epinephelus guttatus, and dominance of trap contents overall by a small, fast-growing species of a lower trophic guild, Acanthurus coeruleus, all point to years of intense fishing pressure.

Garrison, V. H.; Rogers, C. S.; Beets, J.; Friedlander, A. M.

2004-01-01

461

How Cross-Language Similarity and Task Demands Affect Cognate Recognition  

ERIC Educational Resources Information Center

This study examines how the cross-linguistic similarity of translation equivalents affects bilingual word recognition. Performing one of three tasks, Dutch-English bilinguals processed cognates with varying degrees of form overlap between their English and Dutch counterparts (e.g., "lamp-lamp" vs. "flood-vloed" vs. "song-lied"). In lexical…

Dijkstra, Ton; Miwa, Koji; Brummelhuis, Bianca; Sappelli, Maya; Baayen, Harald

2010-01-01

462

Cigarette Smoking and Abstinence: Comparative Effects Upon Cognitive Task Performance and Mood State over 24 Hours  

Microsoft Academic Search

Twenty regular smokers were assessed over 24-h of normal cigarette smoking, and an equivalent period of abstinence. In both conditions, a non-deprived baseline was followed by performance tests 2, 6 and 24 h later, while subjective feelings were assessed every 2 h. Compared to normal smoking, abstinence led to reduced heart rate, worse task performance, feelings of depression, stress, irritability,

A. C. PARROTT; N. J. GARNHAM; K. WESNES; C. PINCOCK

1996-01-01

463

Application of Task Theory to Task Analysis: Evaluation of Validity and Reliability using Sample Tasks.  

National Technical Information Service (NTIS)

The research to date has provided a first evaluation of the validity and reliability of a task analysis performed and an instructional procedure for training individuals to perform the analysis. Specifically, problems performed on desk and pocket calculat...

M. H. Companion W. H. Teichner

1977-01-01

464

Bluelight-induced, flavin-mediated transport of redox equivalents across artificial bilayer membranes  

SciTech Connect

This paper continues studies of physico-chemical properties of vesicle-bound flavins. Based on previous results, an advanced model system was designed in order to study the mechanisms underlying bluelight-induced redox transport across artificial membranes. The lumen of single-shelled vesicles was charged with cytochrome c, and amphiphilic flavin (AF1 3, AF1 10) was bound to the membrane. Upon bluelight irradiation redox equivalents are translocated from exogeneous 1e-(EDTA)-and 2e-(BH3CN-) donors across the membrane finally reducing the trapped cytochrome c both under aerobic and anaerobic conditions. The mechanisms involved are explored and evidence for the involvement of various redox states of oxygen, dihydroflavin and flavosemiquinone is presented.

Schmidt, W.

1984-01-01

465

Polishing a Data Task: Seeking Better Assessment.  

ERIC Educational Resources Information Center

Shares a teacher's stages of selecting and revising a performance-assessment task focusing on data handling. Discusses selection and revision criteria, examining student work, reflecting on the task, and revising the final task. (MKR)

Zawojewski, Judith S.

1996-01-01

466

78 FR 27969 - Meeting of the Community Preventive Services Task Force (Task Force)  

Federal Register 2010, 2011, 2012, 2013

...Prevention Meeting of the Community Preventive Services Task Force (Task Force...the next meeting of the Community Preventive Services Task Force (Task Force...to Community Preventive Services (Community Guide). DATES: The...

2013-05-13

467

78 FR 59939 - Meeting of the Community Preventive Services Task Force (Task Force)  

Federal Register 2010, 2011, 2012, 2013

...Prevention Meeting of the Community Preventive Services Task Force (Task...next meeting of the Community Preventive Services Task Force (Task...Andrea Baeder, The Community Guide Branch, Division...Analysis, and Library Services (proposed),...

2013-09-30

468

78 FR 63208 - UPDATE-Meeting of the Community Preventive Services Task Force (Task Force)  

Federal Register 2010, 2011, 2012, 2013

...UPDATE--Meeting of the Community Preventive Services Task Force (Task Force...update to the meeting of the Community Preventive Services Task Force (Task Force...to Community Preventive Services (Community Guide). DATES: The...

2013-10-23

469

77 FR 56845 - Meeting of the Community Preventive Services Task Force (Task Force)  

Federal Register 2010, 2011, 2012, 2013

...Prevention Meeting of the Community Preventive Services Task Force (Task Force...the next meeting of the Community Preventive Services Task Force (Task Force...to Community Preventive Services (Community Guide). DATES: The...

2012-09-14

470

32 CFR 643.117 - Hunting, trapping, and fishing.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 2010-07-01 true Hunting, trapping, and fishing. 643.117 Section 643.117 National...Additional Authority of Commanders § 643.117 Hunting, trapping, and fishing. Applications to hunt, trap, and...

2010-07-01

471

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Hunting, fishing, and trapping. 423.32 Section...Conduct § 423.32 Hunting, fishing, and trapping. (a) You may...restrictions pertaining to hunting, fishing, and trapping established by an...

2010-10-01

472

32 CFR 643.117 - Hunting, trapping, and fishing.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Hunting, trapping, and fishing. 643.117 Section 643.117 National...Additional Authority of Commanders § 643.117 Hunting, trapping, and fishing. Applications to hunt, trap, and...

2009-07-01

473

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Hunting, fishing, and trapping. 423.32 Section...Conduct § 423.32 Hunting, fishing, and trapping. (a) You may...restrictions pertaining to hunting, fishing, and trapping established by an...

2009-10-01

474

Response of a tissue equivalent proportional counter to neutrons  

NASA Technical Reports Server (NTRS)

The absorbed dose as a function of lineal energy was measured at the CERN-EC Reference-field Facility (CERF) using a 512-channel tissue equivalent proportional counter (TEPC), and neutron dose equivalent response evaluated. Although there are some differences, the measured dose equivalent is in agreement with that measured by the 16-channel HANDI tissue equivalent counter. Comparison of TEPC measurements with those made by a silicon solid-state detector for low linear energy transfer particles produced by the same beam, is presented. The measurements show that about 4% of dose equivalent is delivered by particles heavier than protons generated in the conducting tissue equivalent plastic. c2002 Elsevier Science Ltd. All rights reserved.

Badhwar, G. D.; Robbins, D. E.; Gibbons, F.; Braby, L. A.

2002-01-01

475

Continuous three-dimensional radiation dosimetry in tissue-equivalent phantoms using electron paramagnetic resonance in L-. cap alpha. -alanine  

SciTech Connect

A new tissue-equivalent phantom material has been developed which also acts as a dosimeter. The new phantom material has a similar elemental composition to that of soft tissue and has a density 1.1 g/cm/sup 3/. The phantom has an agar-gel base, and contains crystallized L-..cap alpha..-alanine which traps radiation-induced free radicals. Samples from the phantom were analyzed by an electron paramagnetic resonance (EPR) spectrometer and the intensity of the EPR signal was related to the absorbed dose. When calibrated, the phantom material acts as a dosimeter, with applications in radiation therapy.

Wielopolski, L.; Maryanski, M.; Ciesielski, B.; Forman, A.; Reinstein, L.E.; Meek, A.G.

1987-07-01

476

On the limitations of the concept of space frequency equivalence  

NASA Technical Reports Server (NTRS)

A narrow-band correlation interferometer using directive (large) antennas is equivalent to a wideband correlation interferometer employing isotropic (small) antennas. This concept of space frequency equivalence, due to Kock and Stone, is reexamined and is shown to hold exactly only for the mean or expected values of the correlation interferometer outputs. If their variances are considered, the equivalence disappears, with the variance fo the wideband system always equal to or greater than that of the narrow-band system.

Macphie, R. H.

1979-01-01

477

Scalable scheduling of tasks in heterogeneous systems  

US Patent & Trademark Office Database

Illustrative embodiments provide a computer implemented method, a data processing system and a computer program product for scalable scheduling of tasks in heterogeneous systems is provided. According to one embodiment, the computer implemented method comprises fetching a set of tasks to form a received input, estimating run times of tasks, calculating average estimated completion times of tasks, producing a set of ordered tasks from the received input to form a task list, identifying a machine to be assigned, and assigning an identified task from the task list to an identified machine.

2013-04-30

478

Task-Irrelevant Perceptual Expertise  

PubMed Central

Perceptual learning (PL) and perceptual expertise (PE) are two fields of visual training studies that investigate how practice improves visual performance. However, previous research suggests that PL can be acquired in a task-irrelevant manner while PE cannot, and that PL is highly specific to the training objects and conditions while PE generalizes. These differences are difficult to interpret since PL and PE studies tend to differ on multiple dimensions. We designed a training study with novel objects to compare PL and PE while varying only the training task, such that the training objects, visual field, training duration and the type of learning assessment were kept constant. Manipulations of the training task sufficed to produce the standard effects obtained in PE and PL. In contrast to prior studies, we demonstrated that some degree of PE can be acquired in a task-irrelevant manner, similar to PL. Task-irrelevant PE resulted in similar shape matching ability compared to the directly trained PE. In addition, learning in both PE and PL generalizes to different untrained conditions, which does not support the idea that PE generalizes while PL is specific. Degrees of generalization can be explained by considering the psychological space of the stimuli used for training and the test of transfer.

Wong, Yetta K.; Folstein, Jonathan R.; Gauthier, Isabel

2012-01-01

479

Fluorescent prey traps in carnivorous plants.  

PubMed

Carnivorous plants acquire most of their nutrients by capturing ants, insects and other arthropods through their leaf-evolved biological traps. So far, the best-known attractants in carnivorous prey traps are nectar, colour and olfactory cues. Here, fresh prey traps of 14 Nepenthes, five Sarracenia, five Drosera, two Pinguicula species/hybrids, Dionaea muscipula and Utricularia stellaris were scanned at UV 366 nm. Fluorescence emissions of major isolates of fresh Nepenthes khasiana pitcher peristomes were recorded at an excitation wavelength of 366 nm. N. khasiana field pitcher peristomes were masked by its slippery zone extract, and prey capture rates were compared with control pitchers. We found the existence of distinct blue fluorescence emissions at the capture spots of Nepenthes, Sarracenia and Dionaea prey traps at UV 366 nm. These alluring blue emissions gradually developed with the growth of the prey traps and diminished towards their death. On excitation at 366 nm, N. khasiana peristome 3:1 CHCl3–MeOH extract and its two major blue bands showed strong fluorescence emissions at 430–480 nm. Masking of blue emissions on peristomes drastically reduced prey capture in N. khasiana pitchers. We propose these molecular emissions as a critical factor attracting arthropods and other visitors to these carnivorous traps. Drosera, Pinguicula and Utricularia prey traps showed only red chlorophyll emissions at 366 nm. PMID:23696970

Kurup, R; Johnson, A J; Sankar, S; Hussain, A A; Sathish Kumar, C; Sabulal, B

2013-05-01

480

Antihydrogen trapping assisted by sympathetically cooled positrons  

NASA Astrophysics Data System (ADS)

Antihydrogen, the bound state of an antiproton and a positron, is of interest for use in precision tests of nature's fundamental symmetries. Antihydrogen formed by carefully merging cold plasmas of positrons and antiprotons has recently been trapped in magnetic traps. The efficiency of trapping is strongly dependent on the temperature of the nascent antihydrogen, which, to be trapped, must have a kinetic energy less than the trap depth of \\sim 0.5\\;{{K}}\\;{{k}_{B}}. In the conditions in the ALPHA experiment, the antihydrogen temperature seems dominated by the temperature of the positron plasma used for the synthesis. Cold positrons are therefore of paramount interest in that experiment. In this paper, we propose an alternative route to make ultra-cold positrons for enhanced antihydrogen trapping. We investigate theoretically how to extend previously successful sympathetic cooling of positrons by laser-cooled positive ions to be used for antihydrogen trapping. Using simulations, we investigate the effectiveness of such cooling in conditions similar to those in ALPHA, and discuss how the formation process and the nascent antihydrogen may be influenced by the presence of positive ions. We argue that this technique is a viable alternative to methods such as evaporative and adiabatic cooling, and may overcome limitations faced by these. Ultra-cold positrons, once available, may also be of interest for a range of other applications.

Madsen, N.; Robicheaux, F.; Jonsell, S.

2014-06-01