These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

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

NASA Astrophysics Data System (ADS)

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

2012-03-01

2

Single and dual task tests of gait speed are equivalent in the prediction of falls in older people: a systematic review and meta-analysis.  

PubMed

Although simple assessments of gait speed have been shown to predict falls as well as hospitalisation, functional decline and mortality in older people, dual task gait speed paradigms have been increasingly evaluated with respect to fall prediction. Some studies have found that dual task walking paradigms can predict falls in older people. A systematic review and meta-analysis was conducted to determine whether dual task walking paradigms involving a secondary cognitive task have greater ability to predict falls than single walking tasks. The meta-analytic findings indicate single and dual task tests of gait speed are equivalent in the prediction of falls in older people and sub-group analyses revealed similar findings for studies that included only cognitively impaired participants, slow walkers or used secondary mental-tracking or verbal fluency tasks. PMID:24915643

Menant, Jasmine C; Schoene, Daniel; Sarofim, Mina; Lord, Stephen R

2014-07-01

3

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

4

Direct indication of lateral nonuniformities of MOS capacitors from the negative equivalent interface trap density based on charge-temperature technique  

NASA Astrophysics Data System (ADS)

The charge-temperature technique was used to investigate the oxide properties of silicon MOS capacitors fabricated on a wafer with an oxide thickness of 660 Å. The stretchout of high frequency C — V curve of the capacitor after a positive charge-temperature aging was proved to be due to the lateral nonuniformities of mobile charges and the increase of interface traps. The effect of lateral nonuniformitites was found to be successfully described by a model consisting of two parallelly connected nonuniform capacitors. The only parameter of importance is their area ratio, which can be easily determined by theoretical fitting. The appearance of a negative equivalent interface trap density was proposed as a new method to directly identify the existence of lateral nonuniformities.

Hwu, J. G.; Wang, W. S.

1986-05-01

5

The ABCs of computerized naming: Equivalency, reliability, and predictive validity of a computerized rapid automatized naming (RAN) task  

Microsoft Academic Search

Population-based studies indicate dual routes to disabled reading in adolescence and adulthood: slowed acquisition of single word reading and ADHD (particularly inattention) in early childhood. Impairments in rapid serial naming may be a factor common to both problems. The gold-standard measure of this ability, the Rapid Automatized Naming Task (RAN; [Denckla MB, Rudel R. Rapid automatized naming of pictured objects,

Ashley E. Howe; Karen M. Arnell; Raymond M. Klein; Marc F. Joanisse; Rosemary Tannock

2006-01-01

6

Search, Enumeration, and Aging: Eye Movement Requirements Cause Age-Equivalent Performance in Enumeration but Not in Search Tasks  

Microsoft Academic Search

Response time (RT) and fixation frequency were measured for young and older adults in search and enumeration tasks under high- and low-attentional competition conditions. There was an age-related decrement in search rates for single targets both for RT and fixation frequency, but there was no deficit in enumeration rates either with or without distractors even though serial enumeration rates were

Derrick G. Watson; Elizabeth A. Maylor; Lucy A. M. Bruce

2005-01-01

7

Facilitation of the equivalence--equivalence responding.  

PubMed

Equivalence-Equivalence responding, based on equivalence class formation, is a key concept of the functional-analytic model of analogical reasoning held by RFT theorists. Relational stimulus control is supposed to play an important role in this arbitrary relational response. Previous research showed that mere training of the prerequisites for equivalence class formation is not always enough for the derivation of equivalence-equivalence responding, even in adults. In the first experiment, with 12 adult participants, we designed a matching-to-sample training and testing procedure that, although it provided all necessary conditions, did not lead to Equivalence-Equivalence responding in most participants, so that the efficacy of a facilitation procedure could be assessed. In Experiment 2, with 32 valid participants, a matching-to-sample procedure based on non-arbitrary relations was introduced to assess its efficacy in enhancing stimulus control by the relational properties of sample and comparisons. Results showed a moderate effect: 40.6% of the participants passed the test after being exposed to a non-arbitrary relational matching task (but none without it). This research underlines the importance of non-arbitrary relational responses in the derivation of more complex repertoires. PMID:21774893

Pérez Fernández, Vicente Jesús; García García, Andrés; Gómez Bujedo, Jesús

2011-08-01

8

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

9

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

10

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

11

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

12

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

13

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

14

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

15

Trapping Coyotes  

E-print Network

, small bushes, animal carcasses, skeletons or other objects. Often there are scratch marks near a scent post which help identify it. Natural scent posts or ones created by a trapper are good loca- tions for trap sets. Trap Sets There are several types... covered with dirt or grass. Any remaining dirt can be scattered away from the holetomakeitappearthatananimalhasdugthe hole. Guided by the coyote sign present, the trap- per should carefully examine the area for good trapsites...

Texas Wildlife Services

2008-04-15

16

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. PMID:16878180

Neuman, Keir C.; Block, Steven M.

2006-01-01

17

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

18

EFFECT OF FILTER TEMPERATURE ON TRAPPING ZINC VAPOR  

Microsoft Academic Search

To address the 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

Korinko

2011-01-01

19

PATHOGEN EQUIVALENCY COMMITTEE UPDATE: PFRP EQUIVALENCY DETERMINATIONS  

EPA Science Inventory

This presentation will: Review the mandate of the Pathogen Equivalency Committee Review the PEC's current membership of 10 Discuss how a typical application is evaluated Note where information can be found List present deliberations/applications and describe t...

20

Equivalence of Syllogisms  

Microsoft Academic Search

We consider two categorical syllogisms, valid or invalid, to be equivalent if they can be transformed into each other by certain trans- formations, going back to Aristotle, that preserve validity. It is shown that two syllogisms are equivalent if and only if they have the same models. Counts are obtained for the number of syllogisms in each equivalence class. For

Fred Richman

2004-01-01

21

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

22

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

23

An Equivalent Gauge and the Equivalence Theorem  

E-print Network

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".

Andrea Wulzer

2013-09-24

24

Task switching  

Microsoft Academic Search

Everyday life requires frequent shifts between cognitive tasks. Research reviewed in this article probes the control processes that reconfigure mental resources for a change of task by requiring subjects to switch frequently among a small set of simple tasks. Subjects' responses are substantially slower and, usually, more error-prone immediately after a task switch. This ‘switch cost’ is reduced, but not

Stephen Monsell

2003-01-01

25

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

26

Equivalent Fractions Finder  

NSDL National Science Digital Library

This activity allows students to visually experiment with the relationship between the values of equivalent fractions and areas within a square or a circle. The activity provides the user with a fraction, its equivalent representation as a shaded portion of a square or circle, and a number line. Also displayed are two empty squares or circles. The user can add and color sections to the blank shapes to create a fraction equivalent to the computer generated fraction.

2007-12-12

27

Interaction of trapped ions with trapped atoms  

E-print Network

In this thesis, I present results from two Paul-trap based ion traps carried out in the Vuleti? laboratory: the Atom-Ion trap for collision studies between cold atoms and cold ions, and the Cavity-Array trap for studying ...

Grier, Andrew T. (Andrew Todd)

2011-01-01

28

Migraine equivalents in childhood.  

PubMed

Migraine equivalents are a group of periodic and paroxysmal neurologic diseases. Because headache is not a prominent symptom, the diagnosis might be challenging. The objective of the study was to evaluate the frequency and outcome of migraine equivalents. This was a retrospective study. We included benign paroxysmal torticollis of infancy, benign paroxysmal vertigo of infancy, abdominal migraine, cyclic vomiting, aura without migraine, and confusional migraine. We evaluated the frequency of events, treatment, and outcome. Out of 674 children with headache, 38 (5.6%) presented with migraine equivalents. Twenty-one were boys and the mean age was 6.1 years. Fifteen had abdominal migraine, 12 benign paroxysmal vertigo, 5 confusional migraine, 3 aura without migraine, 2 paroxysmal torticollis, and 1 cyclic vomiting. Prophylactic treatment was introduced in 23 patients; 4 lost follow-up and 19 had significant improvement. We conclude that the correct diagnosis of migraine equivalents enables an effective treatment with an excellent outcome. PMID:24092892

Teixeira, Karine C S; Montenegro, Maria Augusta; Guerreiro, Marilisa M

2014-10-01

29

Beyond Network Equivalence  

E-print Network

In earlier work, we described an equivalence result for network capacity. Roughly, that result is as follows. Given a network of noisy, memoryless, point-to-point channels, replace each channel by a noiseless, memoryless ...

Koetter, Ralf

30

Achieving cold antiprotons in a Penning trap  

SciTech Connect

The current state of proton/electron trapping sensitivity at Washington requires only small numbers (less than or equal to 100) of anti p be trapped in order to achieve high signal to noise ratios. We therefore investigated a anti p trapping scheme based on stopping foils which, in the simplest case, require no auxiliary decelerator/cooler past a LEAR (or equivalent) stage. Cooling of the trapped particles could be accomplished via the damping provided by an external resistor as in all of the other experiments. The rate of this cooling would be rather low, even in the most ideal case, and likely would be much lower when the electrostatic anharmonicity of such a trap is realistically considered. We thereby examined a possible alternate cooling scheme, electron cooling with a buffer gas of cold electrons, in order to improve the cooling rate. 18 references.

Kells, W.; Gabrielse, G.; Helmerson, K.

1984-08-01

31

Fractions--Equivalent  

NSDL National Science Digital Library

Students use this virtual manipulative to visualize and name equivalent fractions. The applet presents a shape divided into equal parts, with some parts shaded. Students change the number of divisions of the shape to visualize equivalent fractions, name the fractions, and check their answers. Instructions for using the applet and teaching ideas for parents/teachers are available through the links at the top of the page.

2000-01-01

32

Steam Trap Application  

E-print Network

The effective application of steam traps encompasses three primary areas which are the selection and sizing, the installation, and the monitoring of the steam trapping system. Proper application of steam traps will improve production rates, product...

Murphy, J. J.

1982-01-01

33

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

34

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.

35

The trapped region  

E-print Network

I will discuss some recent results on marginally outer trapped surfaces, apparent horizons, and the trapped region. A couple of applications of the results developed for marginally outer trapped surfaces to coalescence of black holes and to the characterization of the trapped region are given.

Lars Andersson

2009-01-17

36

Are All Psychotherapies Equivalent?  

Microsoft Academic Search

Despite clear demonstrations by process researchers of systematic differences in therapists' techniques, most reviews of psychotherapy outcome research show little or no differential effectiveness of different psychotherapies. This contradiction presents a dilemma to researchers and practitioners. Numerous possible solutions have been suggested. Some of these challenge the apparent equivalence of outcome, arguing that differential results could be revealed by more

William B. Stiles; David A. Shapiro; Robert Elliott

1986-01-01

37

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

38

The Interaction Equivalency Theorem  

ERIC Educational Resources Information Center

This paper examines the key issues regarding The Interaction Equivalency Theorem posited by Anderson (2003a), which consists of the three interaction elements found in formal education courses among teacher, student, and content. It first examines the core concepts of the theorem and argues that two theses of different dimensions can be…

Miyazoe, Terumi; Anderson, Terry

2010-01-01

39

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

40

POVERTY EQUIVALENT GROWTH RATE  

Microsoft Academic Search

This paper proposes a new type of growth rate, called the “poverty equivalent growth rate” (PEGR), which takes into account both the growth rate in mean income and how the benefits of growth are distributed between the poor and the non-poor. The proposed measure satisfies a basic requirement that the proportional reduction in poverty is a monotonically increasing function of

N anak K akwani; H yun H. S on

2008-01-01

41

Equivalence in radionuclide metrology  

Microsoft Academic Search

The harmonization of different National Measurement Systems depends on the ability to demonstrate Equivalence between them. The responsibility for establishing a procedure to achieve this lies with the International Committee of Weights and Measures (CIPM) and its associated Consultative Committees. In pursuit of these ends, a series of general recommendations and procedures have been developed by BIPM in order to

M. J. Woods; D. F. G. Reher; G. Ratel

2000-01-01

42

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

43

Free products, Orbit Equivalence and Measure Equivalence Rigidity  

E-print Network

Free products, Orbit Equivalence and Measure Equivalence Rigidity Aur´elien Alvarez and Damien Gaboriau February 18, 2009 Abstract We study the analogue in orbit equivalence of free product decomposition and free indecomposability for countable groups. We introduce the (orbit equivalence invariant

Paris-Sud XI, Université de

44

Multiple paths in complex tasks  

NASA Technical Reports Server (NTRS)

The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise.

Galanter, Eugene; Wiegand, Thomas; Mark, Gloria

1987-01-01

45

Steam Trap Users' Guide.  

National Technical Information Service (NTIS)

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 activ...

D. M. Sneed, J. C. King

1985-01-01

46

Learning Tasks  

ERIC Educational Resources Information Center

Government budget constraints had forced the Emergency Dispatch Center (EDC) at a military installation to work with less than the normal number of staff. A Program Proposal was developed previously that had determined that a learning gap existed in the researcher's work environment at a military installation. To counter this gap, Learning Tasks

Baskas, Richard S.

2012-01-01

47

HP Steam Trap Monitoring  

E-print Network

STEAM MONITORING HP Steam Trap Monitoring HP Steam Trap Monitoring ? 12-18 months payback! ? 3-5% permanent reduction in consumption ? LEED Pt.? Innovation in Operations EB O&M ? Saved clients over $1,000,000 Annual consumption... Steam Trap Monitoring ? Real-time monitoring for high-pressure critical traps (>15 PSIG) ? Average total system cost $25K - $50K ? Web-Based or Modbus/BMS Integration Basic Installation Wireless Signal Transmitter Receiver Repeater...

Pascone, S.

2011-01-01

48

Sorption vacuum trap  

NASA Technical Reports Server (NTRS)

Modified sorption trap for use in high vacuum systems contains provisions for online regeneration of sorbent material. Trap is so constructed that it has a number of encapsulated resistance heaters and a valving and pumping device for removing gases from heated sorbing material. Excessive downtime is eliminated with this trap.

Barrington, A. E.; Caruso, A. J.

1970-01-01

49

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.

50

Superconducting microfabricated ion traps  

E-print Network

We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

Shannon X. Wang; Yufei Ge; Jaroslaw Labaziewicz; Eric Dauler; Karl Berggren; Isaac L. Chuang

2010-10-28

51

Conformal equivalence of triangle meshes  

Microsoft Academic Search

We present a new algorithm for conformal mesh parameterization. It is based on a precise notion of discrete conformal equivalence for triangle meshes which mimics the notion of conformal equivalence for smooth surfaces. The problem of finding a flat mesh that is discretely conformally equivalent to a given mesh can be solved efficiently by minimizing a convex energy function, whose

Boris Springborn; Peter Schröder; Ulrich Pinkall

2008-01-01

52

Problems in modelling tasks and task views  

Microsoft Academic Search

We present the rudiments of a new theory of tasks and task views. The motivating idea is essentially as follows: in an environment in which several organizational agents cooperate to accomplish a common task, each of the agents need only know its own part of the task — this is the agent's task view. The underlying computer system may take

Murray S. Mazer

1988-01-01

53

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

54

Neutral atom traps.  

SciTech Connect

This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

Pack, Michael Vern

2008-12-01

55

Evaluating Steam Trap Performance  

E-print Network

The variables are listed below, algebraic symools. used along in the economic with their unit an~lysis and Variable No. Symbol Description 1 2 3 P T P RK HI price of trap, dollars price of repair kit, doll time required to install rs trap... The variables are listed below, algebraic symools. used along in the economic with their unit an~lysis and Variable No. Symbol Description 1 2 3 P T P RK HI price of trap, dollars price of repair kit, doll time required to install rs trap...

Fuller, N. Y.

56

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

57

Equivalent Turing Machine Models Many variations on TMs are equivalent.  

E-print Network

1 Equivalent Turing Machine Models Many variations on TMs are equivalent. 1. Stay option. Read. Off-line TM. Two tapes, one for input, and the other for working storage. 4. Multitape TMs. TM has a finite number of tapes. 5. Multidimensional TMs. Tape is two-dimensional like a matrix. Nondeterministic

Bylander, Tom

58

Buffer strips trap contaminants  

E-print Network

ater Buffer strips trap contaminants Three research and demonstration projects seek to determine ideal width for riparian buffer strips in Midwest. They trap sediment, nutrients and pesticides. That ma kes riparian buffer strips a valuable tool in preventing nonpo int sour ce pollution, according

Nebraska-Lincoln, University of

59

Steam Trap Monitor.  

National Technical Information Service (NTIS)

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...

M. J. Ryan

1987-01-01

60

Optical trapping of nanoparticles.  

PubMed

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping and manipulating small biological particles. Ashkin and co-workers first demonstrated optical tweezers using a single focused beam. The single beam trap can be described accurately using the perturbative gradient force formulation in the case of small Rayleigh regime particles. In the perturbative regime, the optical power required for trapping a particle scales as the inverse fourth power of the particle size. High optical powers can damage dielectric particles and cause heating. For instance, trapped latex spheres of 109 nm in diameter were destroyed by a 15 mW beam in 25 sec, which has serious implications for biological matter. A self-induced back-action (SIBA) optical trapping was proposed to trap 50 nm polystyrene spheres in the non-perturbative regime. In a non-perturbative regime, even a small particle with little permittivity contrast to the background can influence significantly the ambient electromagnetic field and induce a large optical force. As a particle enters an illuminated aperture, light transmission increases dramatically because of dielectric loading. If the particle attempts to leave the aperture, decreased transmission causes a change in momentum outwards from the hole and, by Newton's Third Law, results in a force on the particle inwards into the hole, trapping the particle. The light transmission can be monitored; hence, the trap can become a sensor. The SIBA trapping technique can be further improved by using a double-nanohole structure. The double-nanohole structure has been shown to give a strong local field enhancement. Between the two sharp tips of the double-nanohole, a small particle can cause a large change in optical transmission, thereby inducing a large optical force. As a result, smaller nanoparticles can be trapped, such as 12 nm silicate spheres and 3.4 nm hydrodynamic radius bovine serum albumin proteins. In this work, the experimental configuration used for nanoparticle trapping is outlined. First, we detail the assembly of the trapping setup which is based on a Thorlabs Optical Tweezer Kit. Next, we explain the nanofabrication procedure of the double-nanohole in a metal film, the fabrication of the microfluidic chamber and the sample preparation. Finally, we detail the data acquisition procedure and provide typical results for trapping 20 nm polystyrene nanospheres. PMID:23354173

Bergeron, Jarrah; Zehtabi-Oskuie, Ana; Ghaffari, Saeedeh; Pang, Yuanjie; Gordon, Reuven

2013-01-01

61

Visuospatial Tasks Affect Locomotor Control More than Nonspatial Tasks in Older People  

PubMed Central

Background Previous research has shown that visuospatial processing requiring working memory is particularly important for balance control during standing and stepping, and that limited spatial encoding contributes to increased interference in postural control dual tasks. However, visuospatial involvement during locomotion has not been directly determined. This study examined the effects of a visuospatial cognitive task versus a nonspatial cognitive task on gait speed, smoothness and variability in older people, while controlling for task difficulty. Methods Thirty-six people aged ?75 years performed three walking trials along a 20 m walkway under the following conditions: (i) an easy nonspatial task; (ii) a difficult nonspatial task; (iii) an easy visuospatial task; and (iv) a difficult visuospatial task. Gait parameters were computed from a tri-axial accelerometer attached to the sacrum. The cognitive task response times and percentage of correct answers during walking and seated trials were also computed. Results No significant differences in either cognitive task type error rates or response times were evident in the seated conditions, indicating equivalent task difficulty. In the walking trials, participants responded faster to the visuospatial tasks than the nonspatial tasks but at the cost of making significantly more cognitive task errors. Participants also walked slower, took shorter steps, had greater step time variability and less smooth pelvis accelerations when concurrently performing the visuospatial tasks compared with the nonspatial tasks and when performing the difficult compared with the easy cognitive tasks. Conclusions Compared with nonspatial cognitive tasks, visuospatial cognitive tasks led to a slower, more variable and less smooth gait pattern. These findings suggest that visuospatial processing might share common networks with locomotor control, further supporting the hypothesis that gait changes during dual task paradigms are not simply due to limited attentional resources but to competition for common networks for spatial information encoding. PMID:25285913

Menant, Jasmine C.; Sturnieks, Daina L.; Brodie, Matthew A. D.; Smith, Stuart T.; Lord, Stephen R.

2014-01-01

62

Equivalence to the Minimum Qualifications.  

ERIC Educational Resources Information Center

Assembly Bill (AB) 1725 provides for the hiring of faculty who do not meet the precise letter of the minimum qualifications, provided that the governing board of an institution determines that an applicant possesses qualifications that are at least equivalent. In order to make these determinations, each district must have and use an equivalency

California Community Colleges, Sacramento. Academic Senate.

63

Surface trap for ytterbium ions  

E-print Network

We conducted an experiment to load a shallow planar ion trap from a cold atom source of Ytterbium using photoionization. The surface trap consisted of a three-rod radio frequency Paul trap fabricated using standard printed ...

Campbell, Jonathan A. (Jonathan Alan)

2006-01-01

64

Visuospatial tasks suppress craving for cigarettes.  

PubMed

The Elaborated Intrusion (EI) theory of desire posits that visual imagery plays a key role in craving. We report a series of experiments testing this hypothesis in a drug addiction context. Experiment 1 showed that a mental visual imagery task with neutral content reduced cigarette craving in abstaining smokers, but that an equivalent auditory task did not. The effect of visual imagery was replicated in Experiment 2, which also showed comparable effects of non-imagery visual working memory interference. Experiment 3 showed that the benefit of visual over auditory interference was not dependent upon imagery being used to induce craving. Experiment 4 compared a visuomotor task, making shapes from modeling clay, with a verbal task (counting back from 100), and again showed a benefit of the visual over the non-visual task. We conclude that visual imagery supports craving for cigarettes. Competing imagery or visual working memory tasks may help tackle craving in smokers trying to quit. PMID:20189549

May, Jon; Andrade, Jackie; Panabokke, Nathalie; Kavanagh, David

2010-06-01

65

Trap-free manipulation in the Landau-Zener system  

E-print Network

The analysis of traps, i.e., locally but not globally optimal controls, for quantum control systems has attracted a great interest in recent years. The central problem that has been remained open is to demonstrate for a given system either existence or absence of traps. We prove the absence of traps and hence completely solve this problem for the important tasks of unconstrained manipulation of the transition probability and unitary gate generation in the Landau-Zener system---a system with a wide range of applications across physics, chemistry and biochemistry. This finding provides the first example of a controlled quantum system which is completely free of traps. We also discuss the impact of laboratory constraints due to decoherence, noise in the control pulse, and restrictions on the available controls which when being sufficiently severe can produce traps.

Alexander Pechen; Nikolay Il'in

2013-04-04

66

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

67

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

68

Trapping and Probing Antihydrogen  

SciTech Connect

Precision spectroscopy of antihydrogen is a promising path to sensitive tests of CPT symmetry. The most direct route to achieve this goal is to create and probe antihydrogen in a magnetic minimum trap. Antihydrogen has been synthesized and trapped for 1000s at CERN by the ALPHA Collaboration. Some of the challenges associated with achieving these milestones will be discussed, including mixing cryogenic positron and antiproton plasmas to synthesize antihydrogen with kinetic energy less than the trap potential of .5K. Recent experiments in which hyperfine transitions were resonantly induced with microwaves will be presented. The opportunity for gravitational measurements in traps based on detailed studies of antihydrogen dynamics will be described. The talk will conclude with a discussion future antihydrogen research that will use a new experimental apparatus, ALPHA-I.

Wurtele, Jonathan [UC Berkeley and LBNL

2013-03-27

69

Equivalence of hybrid dynamical models  

Microsoft Academic Search

Abstract: this report, please use the following reference instead:W.P.M.H. Heemels, B. De Schutter, and A. Bemporad, \\\\Equivalence of hybriddynamical models," Automatica, vol. 37, no. 7, pp. 1085-1091, July 2001

W. P. M. H. Heemels; Bart De Schutter; Alberto Bemporad

2001-01-01

70

50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.  

Code of Federal Regulations, 2011 CFR

...limits and trap tag requirements for vessels fishing with lobster traps. 697.19 Section...limits and trap tag requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish in any...

2011-10-01

71

50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.  

Code of Federal Regulations, 2010 CFR

...limits and trap tag requirements for vessels fishing with lobster traps. 697.19 Section...limits and trap tag requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish in any...

2010-10-01

72

50 CFR 697.19 - Trap limits and trap tag requirements for vessels fishing with lobster traps.  

Code of Federal Regulations, 2012 CFR

...limits and trap tag requirements for vessels fishing with lobster traps. 697.19 Section...limits and trap tag requirements for vessels fishing with lobster traps. (a) Trap limits for vessels fishing or authorized to fish in any...

2012-10-01

73

Transfer of a conditional ordering response through conditional equivalence classes.  

PubMed

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. PMID:16812554

Wulfert, E; Hayes, S C

1988-09-01

74

Sequential task predictability in task switching  

Microsoft Academic Search

Many studies of task switching have found that a prolonged preparation time reduces switch costs. An alternative manipulation\\u000a of task preparation is based on sequential task predictability, rather than preparation time. In Experiments 1 and 2 of the\\u000a present study, participants performed explicitly instructed task sequences (i.e., AABB) and were then transferred to a random\\u000a sequence. The observed benefit of

Iring Koch; Max Planck

2005-01-01

75

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

76

From equivalent weighting functions to equivalent contraction kernels  

NASA Astrophysics Data System (ADS)

Burt introduced 1983 'equivalent weighting function': 'Iterative pyramid generation is equivalent to convolving the image g0 with a set of 'equivalent weighting functions' hl' gl equals hl * g0 equals h * gl-1, l > 1. It allowed him to study the effects of iterated reduction using the single parameter hl without giving up the efficient iterative computation. A similar concept applies to graph pyramids built by dual graph contraction. This new algorithm reduces the number of vertices and of edges of a pair of dual image graphs while, at he same time, the topological relations among the 'surviving' components are preserved. Repeated application produces a stack of successively smaller graphs: a pari of dual irregular pyramids. The process is controlled by selected decimation parameters which consist of a subset of surviving vertices and associated contraction kernels. These pay a similar role for graph pyramids than the convolution kernels of Gaussian pyramids. Equivalent contraction kernels combine two or more contraction kernels int one single dual contraction. The basic concepts are elaborated and discussed. The new theory opens a large variety of possibilities to explore the domain of 'all' graph pyramids.

Kropatsch, Walter G.

1998-02-01

77

Equivalence principle for scalar forces.  

PubMed

The equivalence of inertial and gravitational masses is a defining feature of general relativity. Here, we clarify the status of the equivalence principle for interactions mediated by a universally coupled scalar, motivated partly by recent attempts to modify gravity at cosmological distances. Although a universal scalar-matter coupling is not mandatory, once postulated, it is stable against classical and quantum renormalizations in the matter sector. The coupling strength itself is subject to renormalization, of course. The scalar equivalence principle is violated only for objects for which either the graviton self-interaction or the scalar self-interaction is important--the first applies to black holes, while the second type of violation is avoided if the scalar is Galilean symmetric. PMID:21231444

Hui, Lam; Nicolis, Alberto

2010-12-01

78

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

79

Doing without the Equivalence Principle  

E-print Network

In Einstein's general relativity, geometry replaces the concept of force in the description of the gravitation interaction. Such an approach rests on the universality of free-fall--the weak equivalence principle--and would break down without it. On the other hand, the teleparallel version of general relativity, a gauge theory for the translation group, describes the gravitational interaction by a force similar to the Lorentz force of electromagnetism, a non-universal interaction. It is shown that, similarly to the Maxwell's description of electromagnetism, the teleparallel gauge approach provides a consistent theory for gravitation even in the absence of the weak equivalence principle.

R. Aldrovandi; J. G. Pereira; K. H. Vu

2004-10-08

80

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

81

Microfabrication techniques for trapped ion quantum information processing  

NASA Astrophysics Data System (ADS)

Quantum-mechanical principles can be used to process information. In one approach, linear arrays of trapped, laser cooled ion qubits (two-level quantum systems) are confined in segmented multi-zone electrode structures. Strong Coulomb coupling between ions is the basis for quantum gates mediated by phonon exchange. Applications of Quantum Information Processing (QIP) include solution of problems believed to be intractable on classical computers. The ion trap approach to QIP requires trapping and control of numerous ions in electrode structures with many trapping zones. In support of trapped ion QIP, I investigated microfabrication of structures to trap, transport and couple large numbers of ions. Using 24Mg + I demonstrated loading and transport between zones in microtraps made of boron doped silicon. This thesis describes the fundamentals of ion trapping, the characteristics of silicon-based traps amenable to QIP work and apparatus to trap ions and characterize traps. Microfabrication instructions appropriate for nonexperts are included. A key characteristic of ion traps is the rate at which ion motional modes heat. In my traps upper bounds on heating were determined; however, heating due to externally injected noise could not be completely ruled out. Noise on the RF potential responsible for providing confinement was identified as one source of injected noise. Using the microfabrication technology developed for ion traps, I made a cantilevered micromechanical oscillator and with coworkers demonstrated a method to reduce the kinetic energy of its lowest order mechanical mode via its capacitive coupling to a driven RF resonant circuit. Cooling results from a RF capacitive force, which is phase shifted relative to the cantilever motion. The technique was demonstrated by cooling a 7 kHz fundamental mode from room temperature to 45 K. Ground state cooling of the mechanical modes of motion of harmonically trapped ions is routine; equivalent cooling of a macroscopic harmonic oscillator has not yet been demonstrated. Extension of this method to devices with higher motional frequencies in a cryogenic system, could enable ground state cooling and may prove simpler than related optical experiments. I also discuss an implementation of the semiclassical quantum Fourier transform (QFT) using three beryllium ion qubits. The QFT is a crucial step in a number of quantum algorithms including Shor's algorithm, a quantum approach to integer factorization which is exponentially faster than the fastest known classical factoring algorithm. This demonstration incorporated the key elements of a scalable ion-trap architecture for QIP.

Britton, Joe

82

Steam Trap Management  

E-print Network

problemA of water hammer and high back pressure. ? Exorbitantly hi~h percentage of cold trapA. ? External steam leaks within the steam trap stations, bypasA valves and/or strainer blowdown valvefl open, blowin~ steam. ! I ? Dirt nssociated... that falls to the "botto Une" on the PE,1. stat"ment. Up to a 500~ return on investment. ? Cash flo\\ol breRk even of fi months or ? Tmproved safety and housekeeping. ? With these henefits at stake,you mighl wonde morc' companies havcn' t i nsti tuted...

Murphy, J. J.; Hirtner, H. H.

83

The Reusable Astronomy Portal (TRAP)  

NASA Astrophysics Data System (ADS)

The Reusable Astronomy Portal (TRAP) aims to provide a common platform for rapidly deploying Astronomy Archives to the web. TRAP is currently under development for both the VAO Data Discovery Portal and the MAST Multi-Mission Portal (Figure 1). TRAP consists of 2 major software packages: the TRAP Client and the TRAP Server. The TRAP framework allows developers to deploy the Server, connect to data resources, then focus on building custom tools for the Client. TRAP is built upon proven industry technologies including the Ext/JS JavaScript Component Library, Mono.NET Web Services, and JSON message based APIs. The multi-layered architecture of TRAP decouples each layer: Client, Service and Data Access, enabling each to evolve independently over time. Although currently deployed to provide astronomy science data access, the TRAP architecture is flexible enough to thrive in any distributed data environment.

Donaldson, T.; Rogers, A.; Wallace, G.

2012-09-01

84

Charge trapping and detrapping in polymeric materials: Trapping parameters  

NASA Astrophysics Data System (ADS)

Space charge formation in polymeric materials can cause some serious concern for design engineers as the electric field may severely be distorted, leading to part of the material being overstressed. This may result in material degradation and possibly premature failure at the worst. It is therefore important to understand charge generation, trapping, and detrapping processes in the material. Trap depths and density of trapping states in materials are important as they are potentially related to microstructure of the material. Changes in these parameters may reflect the aging taken place in the material. In the present paper, characteristics of charge trapping and detrapping in low density polyethylene (LDPE) under dc electric field have been investigated using the pulsed electroacoustic (PEA) technique. A simple trapping and detrapping model based on two trapping levels has been used to qualitatively explain the observation. Numerical simulation based on the above model has been carried out to extract parameters related to trapping characteristics in the material. It has been found that the space charge decaying during the first few hundred seconds corresponding to the fast changing part of the slope was trapped with the shallow trap depth 0.88 eV, with trap density 1.47 × 1020 m-3 in the sample volume measured. At the same time, the space charge that decays at longer time corresponding to the slower part of the slope was trapped with the deep trap depth 1.01 eV, with its trap density 3.54 × 1018 m-3. The results also indicate that trap depths and density of both shallow and deep traps may be used as aging markers as changes in the material will certainly affect trapping characteristics in terms of trap depth and density.

Zhou, Tian-chun; Chen, George; Liao, Rui-jin; Xu, Zhiqiang

2011-08-01

85

Quantum computation and simulation with trapped ions using dissipation  

E-print Network

Quantum computation and simulation with trapped ions using dissipation Dissertation zur Erlangung and computer science. A quantum computer promises to solve certain problems more efficient than classical computers. But building such a quantum computer is a cumbersome task as the quantum system needs

Blatt, Rainer

86

Measurement of Trap Length for an Optical Trap  

NASA Technical Reports Server (NTRS)

The trap length along the beam axis for an optical trap formed with an upright, oil-immersion microscope was measured. The goals for this effort were twofold. It was deemed useful to understand the depth to which an optical trap can reach for purposes of developing a tool to assist in the fabrication of miniature devices. Additionally, it was desired to know whether the measured trap length favored one or the other of two competing theories to model an optical trap. The approach was to trap a microsphere of known size and mass and raise it from its initial trap position. The microsphere was then dropped by blocking the laser beam for a pre-determined amount of time. Dropping the microsphere in a free-fall mode from various heights relative to the coverslip provides an estimate of how the trapping length changes with depth in water in a sample chamber on a microscope slide. While it was not possible to measure the trap length with sufficient precision to support any particular theory of optical trap formation, it was possible to find regions where the presence of physical boundaries influenced optical traps, and determine that the trap length, for the apparatus studied, is between 6 and 7 m. These results allow more precise control using optical micromanipulation to assemble miniature devices by providing information about the distance over which an optical trap is effective.

Wrbanek, Susan Y.

2009-01-01

87

HWVP Iodine Trap Evaluation  

SciTech Connect

This report details our assessment of the chemistry of the planned Hanford Waste Vitrification Plant (HWVP) off-gas system and its impact on the applicability of known iodine removal and control methods. To predict the gaseous species in the off-gas system, we completed thermodynamic calculations to determine theoretical equilibrium concentrations of the various potential chemical species. In addition, we found that HWVP pilot-plant experiments were generally consistent with the known chemistry of the individual elements present in the off gas. Of the known trapping techniques for radioiodine, caustic scrubbing and silver-containing sorbents are, in our opinion, the most attractive methods to reduce the iodine concentration in the HWVP melter off gas (MOG) after it has passed through the high-efficiency particulate air (HEPA) filter. These two methods were selected because they (1) have demonstrated retention factors (RFs), ratio of amount in and amount out, of 10 to 1000, which would be sufficient to reduce the iodine concentration in the MOG to below regulatory limits; (2) are simple to apply; (3) are resistant to oxidizing gases such as NOx; (4) do not employ highly hazardous or highly corrosive agents; (5) require containment vessels constructed or common materials; (6) have received extensive laboratory development; (7) and the radioactive wastes produced should be easy to handle. On the basis of iodine trapping efficiency, simplicity of operation, and waste management, silver sorbents are superior to caustic scrubbing, and, or these sorbents, we prefer the silver zeolites. No method has been fully demonstrated, from laboratory-scale through pilot-plant testing, to be an effective iodine trap at the low iodine concentration (2 x 10-11 mol I/L) expected in the MOG of the HWVP in the presence of the other gaseous off gas components. In terms of compatibility of the trapping technology with the components in the MOG, there is some question about the resistance of the silver zeolite's aluminosilicate matrix to the fluoride component in the off gas. The caustic scrubber has no compatibility problems with the MOG off gas; however, the acidic components such as CO2 will increase the volume of waste produced and could affect the efficiency of the iodine trapping. To apply these gaseous iodine trapping technologies to the HWVP, further development work would be required. Neither method has been demonstrated at the very low iodine concentrations that exist in the off gas, which are 0.01% to 1% of the found in nuclear fuel dissolver off gases for which these technologies were developed. Furthermore, the large excess of other reactive and trappable gases in the HWVP off gas imposes a heavy load on the trapping medium, could impede iodine trapping, and could have deleterious effects on the trapping medium itself. For silver zeolites, other trappable gases such as chlorine, which are in gross excess of the iodine in the off gas, will compete for the active sites in the silver zeolite. In applying a silver zeolite to the HWVP, 99-9% of the silver would be used to trap chlorine with less than 0.1% of the silver employed in the zeolite bed used for iodine trapping. It is also difficult to predict what will happen when the aluminosilicate framework of the zeolite is exposed to the reactive gas, HF, which is also present in the off gas and is known to attack silicates. In the case of caustic scrubbing, because of the low iodine concentration in the off gas, essentially all of the caustic will be used for CO2 removal, a small fraction for chlorine and fluorine removal, and a trace amount for iodine removal. NO2, which should exist largely as NO, will not be removed.

Burger, Leland L.; Scheele, Randall D.

2004-09-24

88

TUFTS IN LONDON PSYCHOLOGY EQUIVALENCIES  

E-print Network

for Psychology majors PSYC2205: Brain & Behaviour PSY 025 (not for BioPsy majors) PSYC2206: Health and Clinical: Organisational Psychology PSY 196g PSYC3109: Psychology of Health PSY 196h PSYC3111: Human-Computer Interface PSYTUFTS IN LONDON PSYCHOLOGY EQUIVALENCIES Tufts in London Tufts Medford PSYC6001: Intro to Social

Patel, Aniruddh D.

89

Acquired Equivalence Changes Stimulus Representations  

ERIC Educational Resources Information Center

Acquired equivalence is a paradigm in which generalization is increased between two superficially dissimilar stimuli (or antecedents) that have previously been associated with similar outcomes (or consequents). Several possible mechanisms have been proposed, including changes in stimulus representations, either in the form of added associations or…

Meeter, M.; Shohamy, D.; Myers, C. E.

2009-01-01

90

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

91

Equivalent Linear Logistic Test Models.  

ERIC Educational Resources Information Center

Discusses the Linear Logistic Test Model (LLTM) and demonstrates that there are many equivalent ways to specify a model. Analyzed a real data set (300 responses to 5 analogies) using a Lagrange multiplier test for the specification of the model, and demonstrated that there may be many ways to change the specification of an LLTM and achieve the…

Bechger, Timo M.; Verstralen, Huub H. F. M.; Verhelst, Norma D.

2002-01-01

92

21 CFR 26.6 - Equivalence assessment.  

Code of Federal Regulations, 2011 CFR

...by the parties to assess equivalence are listed in appendix...programs for assessing the equivalence of the respective regulatory...inspections and for various product classes or processes. (c) The equivalence assessment shall...

2011-04-01

93

21 CFR 26.9 - Equivalence determination.  

Code of Federal Regulations, 2011 CFR

...Manufacturing Practices § 26.9 Equivalence determination. (a) Equivalence is established by...preapproval) or product classes or processes. (b) The...insufficient evidence of equivalence, lack of opportunity...

2011-04-01

94

Nuclear Physics with trapped  

E-print Network

Nuclear Physics with trapped atoms and ions #12;2/2/2013Dan Melconian #12;2/2/2013Dan Melconian Outline · Scope and applications of nuclear physics precision frontier compliments LHC properties and aquifers in the Sahara #12;2/2/2013Dan Melconian What is Nuclear Physics? · Began with the study

Boas, Harold P.

95

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

96

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

97

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. PMID:23126750

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

2012-01-01

98

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

99

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.

100

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

101

Protocols for evaluating equivalency of accelerometry-based activity monitors.  

PubMed

A wide array of accelerometer-based activity monitors has been developed to facilitate objective monitoring of physical activity behaviors, but it has proven difficult to equate outputs from different monitors. On the surface, commercially available monitors seem to be performing the same basic task-monitoring total body acceleration. However, differences in sensor properties and internal data processing have made it difficult to directly compare output from different monitors. In recent years, many new competing technologies have been released into the market, compounding the challenge of evaluating monitor equivalency and the relative strengths and limitations of different monitors. To advance physical activity assessment and improve our ability to compare results across studies using different monitors, it is important to conduct functional equivalency studies in a standardized and systematic way. This article summarizes issues associated with monitor equivalency and proposes methods for standardization and quality control in future research. PMID:22157773

Welk, Gregory J; McClain, James; Ainsworth, Barbara E

2012-01-01

102

Trapping cold molecular hydrogen.  

PubMed

Translationally cold H(2) molecules excited to non-penetrating |M(J)| = 3 Rydberg states of principal quantum number in the range 21-37 have been decelerated and trapped using time-dependent inhomogeneous electric fields. The |M(J)| = 3 Rydberg states were prepared from the X (1)?(+)(u)(v = 0, J = 0) ground state using a resonant three-photon excitation sequence via the B (1)?(+)(u)(v = 3, J = 1) and I (1)?(g) (v = 0, J = 2) intermediate states and circularly polarized laser radiation. The circular polarization of the vacuum ultraviolet radiation used for the B ? X transition was generated by resonance-enhanced four-wave mixing in xenon and the degree of circular polarization was determined to be 96%. To analyse the deceleration and trapping experiments, the Stark effect in Rydberg states of molecular hydrogen was calculated using a matrix diagonalization procedure similar to that presented by Yamakita et al., J. Chem. Phys., 2004, 121, 1419. Particular attention was given to the prediction of zero-field positions of low-l states and of avoided crossings between Rydberg-Stark states with different values of |M(J)|. The calculated Stark maps and probabilities for diabatic traversal of the avoided crossings were used as input to Monte-Carlo particle-trajectory simulations. These simulations provide a quantitatively satisfactory description of the experimental data and demonstrate that particle loss caused by adiabatic traversals of avoided crossings between adjacent |M(J)| = 3 Stark states of H(2) is small at principal quantum numbers beyond n = 25. The main source of trap losses was found to be from collisional processes. Predissociation following the absorption of blackbody radiation is estimated to be the second most important trap-loss mechanism at room temperature, and trap loss by spontaneous emission is negligible under our experimental conditions. PMID:21818497

Seiler, Ch; Hogan, S D; Merkt, F

2011-11-14

103

`Border traps' in MOS devices  

Microsoft Academic Search

The author recommends that the terminology for oxide charges developed in 1979 be updated to include near-interfacial oxide traps that communicate with the underlying Si and that these defects collectively be called border traps. Justification for this nomenclature is presented and defining features of border traps are discussed. Border traps play an important role in determining low-frequency (1\\/f) noise levels

Daniel M. Fleetwood

1992-01-01

104

The Elimination of Steam Traps  

E-print Network

Engineering 9 February 9, 1981 Trap manufacturers are very supportive toward maintenance. They provide literature and discus sions on how to set up a steam trap maintenance program. Handy index cards and metal tags are made available to help a facility... Engineering 9 February 9, 1981 Trap manufacturers are very supportive toward maintenance. They provide literature and discus sions on how to set up a steam trap maintenance program. Handy index cards and metal tags are made available to help a facility...

Dickman, F.

105

Everyday Peripheral Tasks vs. Digital Peripheral Tasks  

E-print Network

while being fully engaged in a conversation or stir the soup on the stove while reading the recipe@cip.ifi.lmu.de Figure 1. Everyday tasks - drinking tea, tying shoe laces and stirring the soup - carried out in the pe- riphery while focusing on another task - reading a book, talking to a colleague, checking the recipe. Work

106

Nondestructive evaluation of steam traps  

NASA Astrophysics Data System (ADS)

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.

Orlove, Gary L.

1999-03-01

107

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

108

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

109

Trapping ions with lasers  

E-print Network

This work theoretically addresses the trapping an ionized atom with a single valence electron by means of lasers, analyzing qualitatively and quantitatively the consequences of the net charge of the particle. In our model, the coupling between the ion and the electromagnetic field includes the charge monopole and the internal dipole, within a multipolar expansion of the interaction Hamiltonian. Specifically, we perform a Power-Zienau-Woolley transformation, taking into account the motion of the center of mass. The net charge produces a correction in the atomic dipole which is of order $m_e/M$ with $m_e$ the electron mass and $M$ the total mass of the ion. With respect to neutral atoms, there is also an extra coupling to the laser field which can be approximated by that of the monopole located at the position of the center of mass. These additional effects, however, are shown to be very small compared to the dominant dipolar trapping term.

Cecilia Cormick; Tobias Schaetz; Giovanna Morigi

2010-12-16

110

Trapping ions with lasers  

E-print Network

This work theoretically addresses the trapping an ionized atom with a single valence electron by means of lasers, analyzing qualitatively and quantitatively the consequences of the net charge of the particle. In our model, the coupling between the ion and the electromagnetic field includes the charge monopole and the internal dipole, within a multipolar expansion of the interaction Hamiltonian. Specifically, we perform a Power-Zienau-Woolley transformation, taking into account the motion of the center of mass. The net charge produces a correction in the atomic dipole which is of order $m_e/M$ with $m_e$ the electron mass and $M$ the total mass of the ion. With respect to neutral atoms, there is also an extra coupling to the laser field which can be approximated by that of the monopole located at the position of the center of mass. These additional effects, however, are shown to be very small compared to the dominant dipolar trapping term.

Cormick, Cecilia; Morigi, Giovanna

2010-01-01

111

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

112

Steam Dynamics - Traps And Coils  

NASA Astrophysics Data System (ADS)

Dynamic monitoring of steam trap and steam coil surface thermal patterns can indicate steam system malfunction. Condensate lines at atmospheric pressure showed a temperature fluctuation of several degrees due to a momentary pressure increase caused by a properly functioning steam trap cycling. A malfunctioning trap showed no such increase. This effect decreases with increased condensate line pressure. Steady state observation of the tempera-ture drop across steam traps could not reliably distinguish good traps from bad. Dynamic observation of steam coil surface temperatures showed a typical 10% to 15% loss of heating surface due to gas blockage. Purging by installing an air vent provides only temporary relief.

Madding, Robert P.; Seeber, Stephen A.

1985-03-01

113

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

114

Equivalent source magnetic dipoles revisited  

NASA Astrophysics Data System (ADS)

Equivalent point source inversion in the rectangular coordinate system has been widely used to reduce satellite magnetic data collected at different altitudes to a common elevation over small areas. This method is based on the expression of the magnetic anomaly caused by a magnetic dipole. Such an expression derived in a spherical coordinate system by von Frese et al. [1981] is found erroneous. We point out the errors in von Frese et al.'s [1981] formulas and present the correct expression for the magnetic field of a magnetic dipole in a spherical coordinate system.

Dyment, J.; Arkani-Hamed, J.

115

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

116

Trapping and separating polar molecules by a hexapole trap  

SciTech Connect

A technique to trap and separate particle of different dipole moment using a hexapole potential is presented. The operation is similar to the method of ion trap mass spectrometer in that the trajectory of a dipole can be described by Mathieu equation. The technique can also be generalized to trap particle of higher order moment by including higher multipole components in the design of the potential.

Pau, S. [Lucent Technologies, Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

2005-09-26

117

Coastally Trapped Wind Reversals  

NSDL National Science Digital Library

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.

Comet

2002-08-06

118

Traps for Rare Isotopes  

NASA Astrophysics Data System (ADS)

Ion traps are widely used in fundamental and applied research. Over the past decade they have also gained significance as tools in experimental nuclear physics. They are used for precision mass measurements, which are important for a better understanding of nuclear structure and the nuclear synthesis of the elements, as well as for precise tests of fundamental interactions. They offer the possibility of textbook-like decay studies, where the nucleus decays in free space. Furthermore, stored ions can be cooled and manipulated in many ways. This is the key to improving the quality of rare isotope beams and for tailoring the beam properties to the needs of the experiments.

Bollen, Georg

119

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

120

In-Trap Spectroscopy of Charge-Bred Radioactive Ions  

NASA Astrophysics Data System (ADS)

In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, In124 and Cs124) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (??) decay.

Lennarz, A.; Grossheim, A.; Leach, K. G.; Alanssari, M.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Crespo López-Urrutia, J. R.; Gallant, A. T.; Holl, M.; Kwiatkowski, A. A.; Lassen, J.; Macdonald, T. D.; Schultz, B. E.; Seeraji, S.; Simon, M. C.; Andreoiu, C.; Dilling, J.; Frekers, D.

2014-08-01

121

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

122

Nano trap for polar molecules  

NASA Astrophysics Data System (ADS)

A new ac/dc monopole trap for neutral polar particles, introduced and explored by Blümel (2011 Phys. Rev. A 83 045402 and 2011 Eur. Phys. J. D 64 85-101), is significantly advanced in several directions. (1) Previously shown to work only for polar classical particles and polar macro-molecules, the trap is shown to work for polar diatomic molecules. (2) A homogeneous electric field, optionally switched on for improved stability in the angular direction, leads to stable trapping in higher order stability regions of the Mathieu equation. (3) Based on the Floquet formalism, analytical and numerical calculations are presented that show that the trap is quantum mechanically stable. (4) Definition and derivation of a quantum pseudo-potential allow a qualitative understanding of the quantum trapping mechanism. (5) It is shown that the proposed ac/dc trap may be realized experimentally using currently available scanning tunnelling microscopy technology.

Blümel, R.

2012-07-01

123

7 CFR 1126.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1126.54 Section 1126.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1126.54 Equivalent price. See § 1000.54. Producer Price...

2010-01-01

124

7 CFR 1033.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1033.54 Section 1033.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1033.54 Equivalent price. See § 1000.54. Producer Price...

2010-01-01

125

7 CFR 1033.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1033.54 Section 1033.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1033.54 Equivalent price. See § 1000.54. Producer Price...

2011-01-01

126

7 CFR 1126.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1126.54 Section 1126.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1126.54 Equivalent price. See § 1000.54. Producer Price...

2011-01-01

127

7 CFR 1032.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1032.54 Section 1032.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1032.54 Equivalent price. See § 1000.54. Producer Price...

2011-01-01

128

7 CFR 1124.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1124.54 Section 1124.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1124.54 Equivalent price. See § 1000.54. Producer Price...

2010-01-01

129

7 CFR 1124.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1124.54 Section 1124.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1124.54 Equivalent price. See § 1000.54. Producer Price...

2011-01-01

130

7 CFR 1001.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1001.54 Section 1001.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1001.54 Equivalent price. See § 1000.54. Producer Price...

2011-01-01

131

7 CFR 1032.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1032.54 Section 1032.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1032.54 Equivalent price. See § 1000.54. Producer Price...

2010-01-01

132

7 CFR 1001.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1001.54 Section 1001.54 Agriculture...MARKETING AREA Order Regulating Handling Class Prices § 1001.54 Equivalent price. See § 1000.54. Producer Price...

2010-01-01

133

Computational equivalence between quantum Turing machines  

E-print Network

Computational equivalence between quantum Turing machines and quantum circuit families Christian by quantum circuit families . . . . . . . . . . . 18 3 Computational equivalence 19 3.1 Encoding with my master's study was to obtain a knowledge about the theoretical foundation of quantum computing

Møller, Jesper Michael

134

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

135

Uniform structures and the equivalence of diffeomorphisms  

Microsoft Academic Search

A new equivalence relation between diffeomorphisms of a compact manifold, viz.,d -equivalence, is defined on the basis of concepts in uniform topology. Thed-equivalence classes of the identity map, the Y-diffeomorphisms of infra-nullmanifolds, and the connection betweend-equivalence and topological entropy are studied. The proofs make use of an effective description of the uniform-homotopy type of the “nonautonomous suspensions over diffeomorphisms” described

A. G. Vainshtein; L. M. Lerman

1978-01-01

136

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

137

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

138

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

139

Classroom Activities for Introducing Equivalence Relations  

ERIC Educational Resources Information Center

Equivalence relations and partitions are two interconnected ideas that play important roles in advanced mathematics. While students encounter the informal notion of equivalence in many courses, the formal definition of an equivalence relation is typically introduced in a junior level transition-to-proof course. This paper reports the results of a…

Brandt, Jim

2013-01-01

140

Existential Types: Logical Relations and Operational Equivalence  

E-print Network

Existential Types: Logical Relations and Operational Equivalence Andrew M. Pitts Cambridge University Computer Laboratory Pembroke Street, Cambridge CB2 3QG, UK Abstract. Existential types have proved of an existential type are semantically equivalent. Of course, it depends what one means by `semantic equivalence

Pitts, Andrew

141

Silent Reading Rates in Grade Equivalents.  

ERIC Educational Resources Information Center

Converts silent reading rates into grade equivalent units. Finds that growth in reading rate is approximately constant each year in school for typical students. Presents grade equivalent data which provides reasonably valid, criterion-referenced grade equivalents that may be used to evaluate the status and progress of individuals or groups. (RS)

Carver, Ronald P.

1989-01-01

142

Do tasks matter in task switching? Dissociating domain-general from context-specific brain activity.  

PubMed

Throughout the past decade, the task-switching paradigm has been used extensively as a tool to delineate the neural mechanisms underlying flexible and goal-directed action control. Yet, given a large number of experimental procedures, the task-switching literature has yielded considerable inconsistencies calling for a systematic evaluation of the impact of methodological parameters. In the present study, we examine a fundamental and implicit assumption that has guided previous research on task switching. Does switch-related brain activation (i.e., the contrast between preparatory activity on switch versus repetition trials) reflect abstract cognitive control processes that are independent of specific task demands, and thus equivalent across different types of tasks? To answer this question, we compared the data of two fMRI studies that examined updating of task goals and/or stimulus-response mappings under almost identical protocols, but using entirely different tasks. In line with an abstract control process view, our results show that the vast majority of switch-related brain activity is insensitive to the context in which it occurs. The only region that exhibited a reliable contextual modulation was the anterior cingulate cortex, indicating that its contribution to preparatory adjustments might be linked to specific task demands. PMID:24875143

Muhle-Karbe, Paul S; De Baene, Wouter; Brass, Marcel

2014-10-01

143

Task Set Formation: Switching to a Completely Novel Task Enhances Task Switching Costs  

E-print Network

Task Set Formation: Switching to a Completely Novel Task Enhances Task Switching Costs Michael W from general task switching. Further, it is unclear how high-level task set formation processes a unique task set formation process, and that it would be reflected in enhanced task switching costs

144

Computer Algebra Systems (CAS) as a Tool for Coaxing the Emergence of Reasoning about Equivalence of Algebraic Expressions  

ERIC Educational Resources Information Center

Equivalence of algebraic expressions is at the heart of transformational work in algebra. However, we know very little about students' understanding of equivalence. This study is part of a larger project that explores the use of CAS as a didactical tool for promoting both technical and conceptual growth in high school algebra with tasks specially…

Kieran, Carolyn; Saldanha, Luis

2005-01-01

145

Simple method to estimate MOS oxide-trap, interface-trap, and border-trap densities  

SciTech Connect

Recent work has shown that near-interfacial oxide traps that communicates with the underlaying Si (``border traps``) can play a significant role in determining MOS radiation response and long-term reliability. Thermally-stimulated-current 1/f noise, and frequency-dependent charge-pumping measurements have been used to estimate border-trap densities in MOS structures. These methods all require high-precision, low-noise measurements that are often difficult to perform and interpret. In this summary, we describe a new dual-transistor method to separate bulk-oxide-trap, interface-trap, and border-trap densities in irradiated MOS transistors that requires only standard threshold-voltage and high-frequency charge-pumping measurements.

Fleetwood, D.M.; Shaneyfelt, M.R.; Schwank, J.R.

1993-09-01

146

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

147

Cryogenic Ion Trapping Systems with Surface-Electrode Traps  

E-print Network

We present two simple cryogenic RF ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 hours. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The vibration amplitude of the closed cycled cryostat was found to be below 106 nm. We evaluated the systems by loading surface-electrode ion traps with $^{88}$Sr$^+$ ions using laser ablation, which is compatible with the cryogenic environment. Using Doppler cooling we observed small ion crystals in which optically resolved ions have a trapped lifetime over 2500 minutes.

P. B. Antohi; D. Schuster; G. M. Akselrod; J. Labaziewicz; Y. Ge; Z. Lin; W. S. Bakr; I. L. Chuang

2008-07-29

148

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

149

Persistence of motor-equivalent postural fluctuations during bipedal quiet standing.  

PubMed

Theoretical and empirical work indicates that the central nervous system is able to stabilize motor performance by selectively suppressing task-relevant variability (TRV), while allowing task-equivalent variability (TEV) to occur. During unperturbed bipedal standing, it has previously been observed that, for task variables such as the whole-body center of mass (CoM), TEV exceeds TRV in amplitude. However, selective control (and correction) of TRV should also lead to different temporal characteristics, with TEV exhibiting higher temporal persistence compared to TRV. The present study was specifically designed to test this prediction. Kinematics of prolonged quiet standing (5 minutes) was measured in fourteen healthy young participants, with eyes closed. Using the uncontrolled manifold analysis, postural variability in six sagittal joint angles was decomposed into TEV and TRV with respect to four task variables: (1) center of mass (CoM) position, (2) head position, (3) trunk orientation and (4) head orientation. Persistence of fluctuations within the two variability components was quantified by the time-lagged auto-correlation, with eight time lags between 1 and 128 seconds. The pattern of results differed between task variables. For three of the four task variables (CoM position, head position, trunk orientation), TEV significantly exceeded TRV over the entire 300 s-period.The autocorrelation analysis confirmed our main hypothesis for CoM position and head position: at intermediate and longer time delays, TEV exhibited higher persistence than TRV. Trunk orientation showed a similar trend, while head orientation did not show a systematic difference between TEV and TRV persistence. The combination of temporal and task-equivalent analyses in the present study allow a refined characterization of the dynamic control processes underlying the stabilization of upright standing. The results confirm the prediction, derived from computational motor control, that task-equivalent fluctuations for specific task variables show higher temporal persistence compared to task-relevant fluctuations. PMID:23110228

Verrel, Julius; Pradon, Didier; Vuillerme, Nicolas

2012-01-01

150

TaskBadges  

NSDL National Science Digital Library

This application is quite simple and is designed to keep life's tasks in order. Billed as "plain-text todo list kung fu," Task Badges adds the number of open tasks in your plain-text todo list to the file's icon so that it shows up in Finder and on the desktop. It's easy to use and it is compatible with Macs running Snow Leopard or Lion.

2012-09-07

151

Transport Task Force Leadership, Task 4  

SciTech Connect

The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport.

Callen, J.D.

1991-07-01

152

Spacetime near isolated and dynamical trapping horizons  

NASA Astrophysics Data System (ADS)

We study the near-horizon spacetime for isolated and dynamical trapping horizons (equivalently marginally outer trapped tubes). The metric is expanded relative to an ingoing Gaussian null coordinate and the terms of that expansion are explicitly calculated to second order. For the spacelike case, knowledge of the intrinsic and extrinsic geometry of the (dynamical) horizon is sufficient to determine the near-horizon spacetime, while for the null case (an isolated horizon) more information is needed. In both cases spacetime is allowed to be of arbitrary dimension and the formalism accommodates both general relativity as well as more general field equations. The formalism is demonstrated for two applications. First, spacetime is considered near an isolated horizon and the construction is both checked against the Kerr-Newman solution and compared to the well-known near-horizon limit for stationary extremal black hole spacetimes. Second, spacetime is examined in the vicinity of a slowly evolving horizon and it is demonstrated that there is always an event horizon candidate in this region. The geometry and other properties of this null surface match those of the slowly evolving horizon to leading order and in this approximation the candidate evolves in a locally determined way. This generalizes known results for Vaidya as well as certain spacetimes known from studies of the fluid-gravity correspondence.

Booth, Ivan

2013-01-01

153

Cryogenic silicon surface ion trap  

E-print Network

Trapped ions are pre-eminent candidates for building quantum information processors and quantum simulators. They have been used to demonstrate quantum gates and algorithms, quantum error correction, and basic quantum simulations. However, to realise the full potential of such systems and make scalable trapped-ion quantum computing a reality, there exist a number of practical problems which must be solved. These include tackling the observed high ion-heating rates and creating scalable trap structures which can be simply and reliably produced. Here, we report on cryogenically operated silicon ion traps which can be rapidly and easily fabricated using standard semiconductor technologies. Single $^{40}$Ca$^+$ ions have been trapped and used to characterize the trap operation. Long ion lifetimes were observed with the traps exhibiting heating rates as low as $\\dot{\\bar{n}}=$ 0.33 phonons/s at an ion-electrode distance of 230 $\\mu$m. These results open many new avenues to arrays of micro-fabricated ion traps.

Michael Niedermayr; Kirill Lakhmanskiy; Muir Kumph; Stefan Partel; Johannes Edlinger; Michael Brownnutt; Rainer Blatt

2014-03-20

154

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

155

Radiation trapping in coherent media  

E-print Network

We show that the effective decay rate of Zeeman coherence, generated in a Rb87 vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced transparency experiments with optically thick media.

A. B. Matsko; I. Novikova; M. O. Scully; G. R. Welch

2001-01-31

156

Quantum optics with trapped ions  

NASA Astrophysics Data System (ADS)

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

1999-03-01

157

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

158

Einstein's equivalence principle in cosmology  

NASA Astrophysics Data System (ADS)

We study physical consequences of the Einstein equivalence principle (EEP) for a Hubble observer in FLRW universe. We introduce the local inertial coordinates with the help of a special conformal transformation. The local inertial metric is Minkowski-flat and materialized by a congruence of time-like geodesics of static observers. The static observers are equipped with the ideal clocks measuring the proper time that is synchronized with the clocks of the Hubble observer. The local inertial metric is used for physical measurements of spacetime intervals with the ideal clocks and rulers. The special conformal transformation preserves null geodesics but does not keep invariant time-like geodesics. Moreover, it makes the rate of the local time coordinate dependent on velocity of the particle which makes impossible to rich the uniform parameterization of the world lines of static observers and light geodesics with a single parameter - they differ by the conformal factor of FLRW metric. It tells us that the metric on the light cone is not Minkowski-flat but depends on the scale factor of FLRW universe and it can be interpreted as a weak violation of EEP for photons. The importance of this violation for gravitational physics is that some of local experiments conducted with freely-propagating electromagnetic waves may be sensitive to the Hubble expansion. We show that the Hubble constant H can be measured within the solar system by means of high-precision spacecraft Doppler tracking as a blue shift of frequency of radio waves circulating in the Earth-spacecraft radio link. We also analyze the behavior of the standing wave in a microwave resonator and show that the standing wave is insensitive to the Hubble expansion.

Kopeikin, Sergei

159

Einstein's equivalence principle in cosmology  

E-print Network

We study physical consequences of the Einstein equivalence principle (EEP) for a Hubble observer in FLRW universe. We introduce the local inertial coordinates with the help of a special conformal transformation. The local inertial metric is Minkowski-flat and materialized by a congruence of time-like geodesics of static observers. The static observers are equipped with the ideal clocks measuring the proper time that is synchronized with the clocks of the Hubble observer. The local inertial metric is used for physical measurements of spacetime intervals with the ideal clocks and rulers. The special conformal transformation preserves null geodesics but does not keep invariant time-like geodesics. Moreover, it makes the rate of the local time coordinate dependent on velocity of the particle which makes impossible to rich the uniform parameterization of the world lines of static observers and light geodesics with a single parameter - they differ by the conformal factor of FLRW metric. It tells us that the metric on the light cone is not Minkowski-flat but depends on the scale factor of FLRW universe and it can be interpreted as a weak violation of EEP for photons. The importance of this violation for gravitational physics is that some of local experiments conducted with freely-propagating electromagnetic waves may be sensitive to the Hubble expansion. We show that the Hubble constant H can be measured within the solar system by means of high-precision spacecraft Doppler tracking as a blue shift of frequency of radio waves circulating in the Earth-spacecraft radio link. We also analyze the behavior of the standing wave in a microwave resonator and show that the standing wave is insensitive to the Hubble expansion.

Sergei M. Kopeikin

2013-11-19

160

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

161

NSI security task: Overview  

NASA Technical Reports Server (NTRS)

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 consulting; and working groups, conferences, and committees.

Tencati, Ron

1991-01-01

162

Debugging tasked Ada programs  

NASA Technical Reports Server (NTRS)

The applications for which Ada was developed require distributed implementations of the language and extensive use of tasking facilities. Debugging and testing technology as it applies to parallel features of languages currently falls short of needs. Thus, the development of embedded systems using Ada pose special challenges to the software engineer. Techniques for distributing Ada programs, support for simulating distributed target machines, testing facilities for tasked programs, and debugging support applicable to simulated and to real targets all need to be addressed. A technique is presented for debugging Ada programs that use tasking and it describes a debugger, called AdaTAD, to support the technique. The debugging technique is presented together with the use interface to AdaTAD. The component of AdaTAD that monitors and controls communication among tasks was designed in Ada and is presented through an example with a simple tasked program.

Fainter, R. G.; Lindquist, T. E.

1986-01-01

163

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

164

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

165

Reduce Steam Trap Failures at Chambers Works  

E-print Network

annualized in only 6 months! 10/20/2010 6Project Y Definitions and Standards Project Y Reduce steam trap failures by 70% Trap Failures from 14% to 4.2% Definitions ? Defect: % failed traps (rapid cycle, leaking, failed open, failed closed...) ? Opportunities = 6782 traps Considerations: ? Biggest Leaks fixed first ? Consider steam loss as secondary Y. ? Identify cold traps quickly in areas where tracing is critical ? Traps affecting Uptime fixed quickly ? Repeat Failures identified...

Kouba, C.

166

Brownian motion of a trapped microsphere ion  

NASA Astrophysics Data System (ADS)

We developed a finite difference simulation for a charged microsphere trapped in a Paul trap at atmospheric pressure undergoing Brownian motion. We demonstrate a theory that shows the variance of the motion of the particle increases both for weak traps and as the trap approaches its instability points. Measurements of the variance for a micron-sized dust particle in an ion trap confirm an increase in the variance as the trap is weakened.

Madsen, M. J.; Skowronski, A. D.

2014-10-01

167

ESD on CHMOS Devices - Equivalent Circuits, Physical Models and Failure Mechanisms  

Microsoft Academic Search

Using new techniques it is possible to construct an EOS\\/ESD equivalent circuit of a product. Location of energy dissipation during an EOS\\/ESD event is determined by a pulsed near infrared technique. Rules for predicting location of ESD dissipation are defined. N+-P-N+ structures and n-channel transistors suffer from a current lock-on effect, which is apparently caused by a runaway oxide trapping

N. Khurana; T. Maloney; W. Yeh

1985-01-01

168

Trap-mulching Argentine ants.  

PubMed

Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies. PMID:17066809

Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

2006-10-01

169

Particle trapping with an rf cavity  

SciTech Connect

It is in principle possible to trap charged particles in an rf cavity. In this note the authors calculate the trapping mechanism of the field pattern given by (1). The trapping occurs for either sign of the charge of the particles. The mode pattern (1) traps particles around the node point (0,0,0). Such a trapping mechanism is of course considered favorable for a particle trap. On the other hand, it may also happen that undesirable stray particles are trapped at nodes of an rf device, which then perturbs the normal operation of an accelerator. Such trappings are then undesirable and are to be avoided.

Chao, A.

1995-11-01

170

46 CFR 110.20-1 - Equivalents.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING GENERAL PROVISIONS Equivalents § 110.20-1...necessary, the Marine Safety Center may require engineering evaluations and tests to demonstrate the...

2012-10-01

171

46 CFR 110.20-1 - Equivalents.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING GENERAL PROVISIONS Equivalents § 110.20-1...necessary, the Marine Safety Center may require engineering evaluations and tests to demonstrate the...

2010-10-01

172

46 CFR 110.20-1 - Equivalents.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING GENERAL PROVISIONS Equivalents § 110.20-1...necessary, the Marine Safety Center may require engineering evaluations and tests to demonstrate the...

2013-10-01

173

46 CFR 110.20-1 - Equivalents.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING GENERAL PROVISIONS Equivalents § 110.20-1...necessary, the Marine Safety Center may require engineering evaluations and tests to demonstrate the...

2011-10-01

174

Nontarget Captures (luring Small Mammal Trapping with Snap Traps  

Microsoft Academic Search

There is little published information available on non-target captures during small mammal trapping. We used a variety of snap traps baited with a rolled oat-peanut butter mix to capture 2,054 individuals from 9 genera of small mammals in a study of small mammal and avian community structure in riparian areas and adjacent loblolly pine (Pinus taeda) plantations. We also captured

David G. Peitz; Philip A. Tappe; Ronald E. Thill; Roger W. Perry; M. Anthony Melchiors; T. Bentiy Wigley

2001-01-01

175

A New Atom Trap The Annular Shell Atom Trap (ASAT)  

E-print Network

In the course of exploring some aspects of atom guiding in a hollow, optical fiber, a small negative potential energy well was found just in front of the repulsive or guiding barrier. This results from the optical dipole and the van der Waals potentials. The ground state for atoms bound in this negative potential well was determined by numerically solving the Schrodinger eq. and it was found that this negative well could serve as an atom trap. This trap is referred to as the Annular Shell Atom Trap or ASAT because of the geometry of the trapped atoms which are located in the locus of points defining a very thin annular shell just in front of the guiding barrier. A unique feature of the ASAT is the compression of the atoms from the entire volume to the volume of the annular shell resulting in a very high density of atoms in this trap. This trap may have applications to very low temperatures using evaporative cooling and possibly the formation of BEC. Finally, a scheme is discussed for taking advantage of the d...

Pilloff, H S; Pilloff, Herschel S.; Horbatsch, Marko

2002-01-01

176

Articulating Syntactic and Numeric Perspectives on Equivalence: The Case of Rational Expressions  

ERIC Educational Resources Information Center

Our study concerns the conceptual mathematical knowledge that emerges during the resolution of tasks on the equivalence of polynomial and rational algebraic expressions, by using CAS and paper-and-pencil techniques. The theoretical framework we adopt is the Anthropological Theory of Didactics ("Chevallard" 19:221-266, 1999), in…

Solares, Armando; Kieran, Carolyn

2013-01-01

177

Auditory-Visual and Visual-Visual Equivalence Relations in Children  

ERIC Educational Resources Information Center

Previous research has suggested that persons with mental retardation evidence equivalence more readily after being trained on auditory-visual than on visual-visual match-to-sample tasks. The present study sought to determine if this discrepancy is also apparent in normally capable preschoolers and whether the derived class-consistent test…

Smeets, Paul M.; Barnes-Holmes, Dermot

2005-01-01

178

Revisiting Evidence for Modularity and Functional Equivalence across Verbal and Spatial Domains in Memory  

ERIC Educational Resources Information Center

The authors revisited evidence in favor of modularity and of functional equivalence between the processing of verbal and spatial information in short-term memory. This was done by investigating the patterns of intrusions, omissions, transpositions, and fill-ins in verbal and spatial serial recall and order reconstruction tasks under control,…

Guerard, Katherine; Tremblay, Sebastien

2008-01-01

179

The earth's trapped radiation belts  

NASA Technical Reports Server (NTRS)

The near-earth charged particle environment is discussed in terms of spacecraft design criteria. Models are presented of the trapped radiation belts and based on in-situ data obtained from spacecraft.

Noll, R. B.; Mcelroy, M. B.

1975-01-01

180

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

181

Data analysis tasks: BATSE  

NASA Technical Reports Server (NTRS)

Miscellaneous tasks related to the operation of, and analysis of data from, the Burst and Transient Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) were performed. The results are summarized and relevant references are included.

Paciesas, William S.

1993-01-01

182

Teaching Equivalence Relations Using Collaborative Activities  

ERIC Educational Resources Information Center

The notion of equivalence relation is a fundamental concept in mathematics and yet mathematics students often are not given formal exposure to it until midway through their college careers. Not only do they need to become adept at working with equivalence relations but they should also understand the wide applicability of this notion. In this…

Mills, Janet E.

2004-01-01

183

7 CFR 1000.54 - Equivalent price.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-01-01 true Equivalent price. 1000.54 Section 1000.54 Agriculture...PROVISIONS OF FEDERAL MILK MARKETING ORDERS Class Prices § 1000.54 Equivalent price. If for any reason a price or pricing...

2010-01-01

184

7 CFR 1000.54 - Equivalent price.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Equivalent price. 1000.54 Section 1000.54 Agriculture...PROVISIONS OF FEDERAL MILK MARKETING ORDERS Class Prices § 1000.54 Equivalent price. If for any reason a price or pricing...

2011-01-01

185

On behavioral equivalence of rational representations  

E-print Network

On behavioral equivalence of rational representations H. L. Trentelman Abstract This article deals with the equivalence of representations of behaviors of linear differential systems. In general, the behavior been working on the issue of representation of system behaviors. This has resulted in an article

Trentelman, Harry L.

186

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

187

Energy Conservation Project Evaluation by Investment Equivalents  

E-print Network

of capital which can be spent to save a unit of energy and still meet the criteria for profitability.' 'Investment Equivalents' can be calculated easily for any form of energy, at any location. The 'Investment Equivalent' can be used to screen energy saving...

Larson, R. J.

1984-01-01

188

Existential Types: Logical Relations and Operational Equivalence  

Microsoft Academic Search

. Existential types have proved useful for classifying variouskinds of information hiding in programming languages, such as occurs inabstract datatypes and objects. In this paper we address the question ofwhen two elements of an existential type are semantically equivalent. Ofcourse, it depends what one means by `semantic equivalence\\

Andrew M. Pitts

1998-01-01

189

PHARMACEUTICAL EQUIVALENCE OF GENERIC ESSENTIAL DRUGS  

Microsoft Academic Search

The use of multisource essential drugs widely contributes to the accessibility to health care for populations in difficulties in developing countries or in case of emergency aids. The issue of bioavailability questions the simplistic theories about drugs interchangeability. Bioequivalence studies must be carried out to ensure the therapeutic equivalence of two pharmaceutic equivalent drugs. However, by looking at drugs circulation

C. ABELLI; O. ANDRIOLLO; L. MACHURON; J. Y. VIDEAU; B. VENNAT; M. P. POUGET

2001-01-01

190

The Equivalence Principle: True or False?  

NSDL National Science Digital Library

This site discusses the equivalence principle, which states that an acceleration effect (inertia) and a gravitational one (attraction between two gravitational masses) are equivalent. The site demonstrates an experiment that demonstrates its validity. Galileo and Einstein's contributions to the principle are also discussed.

2010-08-30

191

Mania and Behavioral Equivalents: A Preliminary Study  

ERIC Educational Resources Information Center

Previous research has failed to address the possibility of behavioral equivalents in people with ID and mania. The relationship between a measure of mania and possible behavioral equivalents was assessed in 693 adults, most with severe or profound ID, living in a large residential setting. The mania subscale of the DASH-II proved to be a…

Sturmey, Peter; Laud, Rinita B.; Cooper, Christopher L.; Matson, Johnny L.; Fodstad, Jill C.

2010-01-01

192

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

193

Task context impacts visual object processing differentially across the cortex  

PubMed Central

Perception reflects an integration of “bottom-up” (sensory-driven) and “top-down” (internally generated) signals. Although models of visual processing often emphasize the central role of feed-forward hierarchical processing, less is known about the impact of top-down signals on complex visual representations. Here, we investigated whether and how the observer’s goals modulate object processing across the cortex. We examined responses elicited by a diverse set of objects under six distinct tasks, focusing on either physical (e.g., color) or conceptual properties (e.g., man-made). Critically, the same stimuli were presented in all tasks, allowing us to investigate how task impacts the neural representations of identical visual input. We found that task has an extensive and differential impact on object processing across the cortex. First, we found task-dependent representations in the ventral temporal and prefrontal cortex. In particular, although object identity could be decoded from the multivoxel response within task, there was a significant reduction in decoding across tasks. In contrast, the early visual cortex evidenced equivalent decoding within and across tasks, indicating task-independent representations. Second, task information was pervasive and present from the earliest stages of object processing. However, although the responses of the ventral temporal, prefrontal, and parietal cortex enabled decoding of both the type of task (physical/conceptual) and the specific task (e.g., color), the early visual cortex was not sensitive to type of task and could only be used to decode individual physical tasks. Thus, object processing is highly influenced by the behavioral goal of the observer, highlighting how top-down signals constrain and inform the formation of visual representations. PMID:24567402

Harel, Assaf; Kravitz, Dwight J.; Baker, Chris I.

2014-01-01

194

Equivalence in Ventilation and Indoor Air Quality  

SciTech Connect

We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

Sherman, Max; Walker, Iain; Logue, Jennifer

2011-08-01

195

Hypnosis, task-motivating instructions, and learning performance  

Microsoft Academic Search

40 Ss, including 30 who had been previously rated as suggestible and 10 as nonsuggestible, were pretested and then retested on equivalent forms of 3 learning tasks: digit symbol substitution, memory for words, and abstract reasoning. All Ss received the pretests in the same way. The 30 suggestible Ss were retested under 1 of the following 3 experimental treatments with

Paul D. Parker; Theodore X. Barber

1964-01-01

196

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

197

Quantum state manipulation of trapped atomic ions  

E-print Network

discussed in this paper. In figure 1, we show schematically a `linear' Paul trap. This trap is based computation; quantum optics; quantum state engineering; trapped atoms 1. Introduction Currently, a major theme oscillating electric fields. The operation of these traps is discussed in various reviews (for example, see

198

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

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

Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit  

ERIC Educational Resources Information Center

This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

201

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

202

TGFF: task graphs for free  

Microsoft Academic Search

We present a user-controllable, general-purpose,pseudorandom task graph generator called TaskGraphs For Free (TGFF). TGFF creates probleminstances for use in allocation and scheduling research.It has the ability to generate independenttasks as well as task sets which are composed of partiallyordered task graphs. A complete description ofa scheduling problem instance is created, includingattributes for processors, communication resources,tasks, and inter-task communication. The user...

Robert P. Dick; David L. Rhodes; Wayne Wolf

1998-01-01

203

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

204

Assessing Therapeutic Equivalence of Three Proportions Using Weighted Likelihood Ratio and Equivalence Cube  

Microsoft Academic Search

A current topic in clinical trials that is capturing the attention and the efforts of researchers is therapeutic equivalence (TE). The drugs are declared to be TE if the confidence intervals about their effectiveness lie within a pre-chosen equivalence range. In this article, we develop a methodology to determine if three treatments are equivalent with respect to their therapeutic effectiveness.

D. Carey; S. Bae; R. Shanmugam; A. A. Bartolucci; K. P. Singh

205

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

206

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

207

The Roles of Timing and Task Order during Task Switching  

Microsoft Academic Search

The neural bases of the different processes involved in task switching remain poorly identified. Whether distinct brain regions are involved according to the overall structure of the task sequence and the predictability of task timing during task switching is unknown. To address this question, we used functional magnetic resonance imaging and a 2 × 2 factorial design varying timing (fixed\\/random)

Jean-Claude Dreher; Etienne Koechlin; Syed Omar Ali; Jordan Grafman

2002-01-01

208

Reconstruction of dose equivalents to the public from the (60)Co Irradiator Facility at the Laboratory for Energy-Related Health Research.  

National Technical Information Service (NTIS)

Because of the uncertainties associated with the dose equivalents received by the public, the DOE has tasked Environmental Management Operations (EMO), as part of the LEHR Environmental Restoration project commissioned by DOE, to reconstruct the dose equi...

T. E. Chapman, R. I. Scherpelz

1991-01-01

209

Relating equivalence relations to equivalence relations: A relational framing model of complex human functioning  

PubMed Central

The current study aimed to develop a behavior-analytic model of analogical reasoning. In Experiments 1 and 2 subjects (adults and children) were trained and tested for the formation of four, three-member equivalence relations using a delayed matching-to-sample procedure. All subjects (Experiments 1 and 2) were exposed to tests that examined relations between equivalence and non-equivalence relations. For example, on an equivalence-equivalence relation test, the complex sample B1/C1 and the two complex comparisons B3/C3 and B3/C4 were used, and on a nonequivalence-nonequivalence relation test the complex sample B1/C2 was presented with the same two comparisons. All subjects consistently related equivalence relations to equivalence relations and nonequivalence relations to nonequivalence relations (e.g., picked B3/C3 in the presence of B1/C1 and picked B3/C4 in the presence of B1/C2). In Experiment 3, the equivalence responding, the equivalence-equivalence responding, and the nonequivalence-nonequivalence responding was successfully brought under contextual control. Finally, it was shown that the contextual cues could function successfully as comparisons, and the complex samples and comparisons could function successfully as contextual cues and samples, respectively. These data extend the equivalence paradigm and contribute to a behaviour-analytic interpretation of analogical reasoning and complex human functioning, in general. PMID:22477120

Barnes, Dermot; Hegarty, Neil; Smeets, Paul M.

1997-01-01

210

Control equivalent turbulence input model for the UH-60 helicopter  

NASA Astrophysics Data System (ADS)

Flight test data from a UH-60 Black Hawk helicopter hovering in the atmospheric turbulence downwind of a large cube-shaped hanger on a wind day were collected. An inverse modeling method was used to extract the control inputs that are required to replicate the portion of the aircraft response attributable to atmospheric disturbances from the flight-test data. Based on the extracted control inputs, a parametric Control Equivalent Turbulence Input (CETI) model comprised of white-noise driven filters that have a Dryden-type form and are scalable for varying levels of turbulence were developed. The outputs of the filters are disturbance time histories that sum with the pilot's inputs, to replicate the effects of atmospheric turbulence in calm atmospheric conditions. A ground-based piloted simulation study was conducted in the NASA/Ames Vertical Motion Simulator (VMS) comparing the empirically based CETI model with flight-test data and with a complex Simulation Of Rotor Blade Element Turbulence (SORBET) model. Two test pilots performed precision hover tasks with increasing levels of simulated turbulence from both the CETI and SORBET models. The results of the simulation study showed good pilot acceptance of the CETI model and provided a good level of validation of the more complex rotating frame turbulence model. An in-flight simulation study was conducted on the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) UH-60 helicopter using the CETI model. Two test pilots performed a precision hover task on calm days with simulated CETI turbulence. Aircraft response metrics showed good agreement between a hover task with CETI simulated turbulence and the same task in atmospheric turbulence. Both pilots commented that the RASCAL's response to CETI turbulence was similar to the response hovering downwind of the large cube-shaped hangar on a windy day. The CETI model developed in this dissertation simulates turbulence by generating equivalent disturbance inputs to the control system of the helicopter. This makes the CETI model suitable for use with any helicopter math model to study the effects of turbulence on handling qualities and for use in designing control systems to reject atmospheric turbulence.

Lusardi, Jeff

211

Snow water equivalent estimation using blackbox optimization  

E-print Network

Feb 23, 2011 ... Abstract: Accurate measurements of snow water equivalent (SWE) is an important factor in managing water .... Positioning objects in the space R3 would ... at each point of the grid, which is referred to as the error map.

Alarie et al.

2011-02-23

212

Distinguishing Provenance Equivalence of Earth Science Data  

NASA Technical Reports Server (NTRS)

Reproducibility of scientific research relies on accurate and precise citation of data and the provenance of that data. Earth science data are often the result of applying complex data transformation and analysis workflows to vast quantities of data. Provenance information of data processing is used for a variety of purposes, including understanding the process and auditing as well as reproducibility. Certain provenance information is essential for producing scientifically equivalent data. Capturing and representing that provenance information and assigning identifiers suitable for precisely distinguishing data granules and datasets is needed for accurate comparisons. This paper discusses scientific equivalence and essential provenance for scientific reproducibility. We use the example of an operational earth science data processing system to illustrate the application of the technique of cascading digital signatures or hash chains to precisely identify sets of granules and as provenance equivalence identifiers to distinguish data made in an an equivalent manner.

Tilmes, Curt; Yesha, Ye; Halem, M.

2010-01-01

213

21 CFR 26.9 - Equivalence determination.  

Code of Federal Regulations, 2013 CFR

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence...

2013-04-01

214

21 CFR 26.6 - Equivalence assessment.  

Code of Federal Regulations, 2012 CFR

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.6 Equivalence...

2012-04-01

215

21 CFR 26.6 - Equivalence assessment.  

Code of Federal Regulations, 2013 CFR

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.6 Equivalence...

2013-04-01

216

21 CFR 26.6 - Equivalence assessment.  

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.6 Equivalence...

2014-04-01

217

21 CFR 26.9 - Equivalence determination.  

Code of Federal Regulations, 2012 CFR

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence...

2012-04-01

218

21 CFR 26.9 - Equivalence determination.  

...HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE...THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence...

2014-04-01

219

33 CFR 67.01-30 - Equivalents.  

Code of Federal Regulations, 2010 CFR

...Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES General Requirements § 67.01-30 Equivalents. The use of alternate equipment,...

2010-07-01

220

21 CFR 26.9 - Equivalence determination.  

Code of Federal Regulations, 2010 CFR

...MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED STATES AND THE EUROPEAN COMMUNITY Specific Sector Provisions for Pharmaceutical Good Manufacturing Practices § 26.9 Equivalence...

2010-04-01

221

21 CFR 26.39 - Equivalence assessment.  

Code of Federal Regulations, 2010 CFR

...MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED STATES AND THE EUROPEAN COMMUNITY Specific Sector Provisions for Medical Devices § 26.39 Equivalence assessment. (a) In...

2010-04-01

222

Introducing Non-Unit Fractions and Equivalence  

NSDL National Science Digital Library

Students interpret fractions in which the denominator describes the number of equal parts and the numerator describes how many of those parts one has. They are also introduced to naming equivalent fractions by dividing a circle.

Wnet

2008-08-22

223

Statistically Equivalent Representative Volume Elements for Unidirectional  

E-print Network

Statistically Equivalent Representative Volume Elements for Unidirectional Composite undergoing initiation and propagation of damage in the form of interfacial debonding. The micro- structural HETEROGENEITIES SUCH as fibers and particles in composite materials make them susceptible to increased damage

Ghosh, Somnath

224

33 CFR 67.01-30 - Equivalents.  

Code of Federal Regulations, 2011 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES General Requirements § 67.01-30 Equivalents. The use of alternate equipment,...

2011-07-01

225

33 CFR 67.01-30 - Equivalents.  

Code of Federal Regulations, 2013 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES General Requirements § 67.01-30 Equivalents. The use of alternate equipment,...

2013-07-01

226

33 CFR 67.01-30 - Equivalents.  

Code of Federal Regulations, 2012 CFR

...Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES General Requirements § 67.01-30 Equivalents. The use of alternate equipment,...

2012-07-01

227

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.

228

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

229

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

230

Determination of effective trapping times for electrons and holes in irradiated silicon  

NASA Astrophysics Data System (ADS)

A set of standard and oxygenated silicon diodes with different resistivities (1 and 15 k? cm ) was irradiated with neutrons to fluences up to 2×10 14 cm-2, 1 MeV neutron NIEL equivalent. After beneficial annealing the signal response from the diodes was studied using transient current technique. Red laser (?=670 nm) illumination was used for creation of electrons and holes. Assuming exponential decrease of the drifting charge in time, the effective trapping probability of electrons and holes was deduced from the evolution of the induced current at voltages above the full depletion voltage. The effective trapping probabilities of holes were found to be larger than of electrons. The trapping probability is shown to scale linearly with fluence. No significant difference between effective trapping probabilities for different materials was measured.

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

2002-01-01

231

Equivalent outdoor temperature for district heating systems  

SciTech Connect

This paper focuses on the influence of various climatic variables on the mass flow in district heating systems. The aim is to establish an equation of what is called the equivalent outdoor temperature. Two possible ways of doing this are considered. In both cases, dynamic models are needed of the mass flow with climatic variables as external inputs. The resulting equation for the equivalent outdoor temperature, which may be nonlinear, shows the equivalent value of each climatic variable in degrees Celsius. Thus, the equivalent temperature can be considered a variable that contains the effect of various weather factors on the mass flow. Measurements from the daily operation of a heating company in Iceland are used in a case study. It is also shown how the uncertainty in the parameters of the equivalent temperature equation can be estimated. The results indicate that, based on the present data, a linear relation between the outdoor temperature, the wind speed, and the number of sunshine hours is adequate for describing the equivalent outdoor temperature.

Jonsson, G.R.; Jonsson, V.K. [Univ. of Iceland, Reykjavik (Iceland). Dept. of Mechanical Engineering

1995-08-01

232

Equivalence Relations, Contextual Control, and Naming  

PubMed Central

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 eight four-member classes were established under the contextual control of two colors. In the presence of one color, conditional relations were established between stimuli whose normative names rhymed. In the presence of the other color, conditional relations were established between stimuli whose normative names did not rhyme. Although, during Experiment 1, all participants demonstrated equivalence classes involving rhyming stimuli, none demonstrated the formation of nonrhyme equivalence classes. To investigate this finding, Experiment 2 evaluated whether participants would demonstrate both rhyme and nonrhyme equivalence classes given more extensive exposure to the experimental contingencies. All participants demonstrated contextually controlled rhyme and nonrhyme equivalence classes, although rhyme classes were demonstrated with greater facility than nonrhyme classes. Results indicate that visual stimuli are named, that verbal bases for stimulus classification can affect the emergence of contextually controlled equivalence classes, and that untrained contextually controlled conditional discriminations involving novel stimuli can emerge on the basis of participants' verbal behavior. PMID:17191757

Randell, Tom; Remington, Bob

2006-01-01

233

Results: Bodies Task Dependence  

E-print Network

of objects in space, such as mental rotation. Egocentric perspective transformations are imagined.) The Same-Different task was unaffected. Mental Spatial Transformations of Bodies and Objects Jeffrey M Systems for Mental Spatial Transformations Evidence is accumulating that multiple systems compute

Zacks, Jeffrey M.

234

Embodied Task Dynamics  

ERIC Educational Resources Information Center

Movement science faces the challenge of reconciling parallel sequences of discrete behavioral goals with observed fluid, context-sensitive motion. This challenge arises with a vengeance in the speech domain, in which gestural primitives play the role of discrete goals. The task dynamic framework has proved effective in modeling the manner in which…

Simko, Juraj; Cummins, Fred

2010-01-01

235

Biomedical applications engineering tasks  

NASA Technical Reports Server (NTRS)

The engineering tasks performed in response to needs articulated by clinicians are described. Initial contacts were made with these clinician-technology requestors by the Southwest Research Institute NASA Biomedical Applications Team. The basic purpose of the program was to effectively transfer aerospace technology into functional hardware to solve real biomedical problems.

Laenger, C. J., Sr.

1976-01-01

236

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

237

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

238

Impact of Static Graphics, Animated Graphics and Mental Imagery on a Complex Learning Task  

ERIC Educational Resources Information Center

The present study compared the impact of different categories of graphics used within a complex learning task. One hundred eighty five native English speaking undergraduates participated in a task that required learning 18 Chinese radicals and their English equivalent translations. A post-test only control group design compared performance…

Lai, Feng-Qi; Newby, Timothy J.

2012-01-01

239

The 1999–2000 task analysis of American nurse-midwifery\\/midwifery practice  

Microsoft Academic Search

A master list of tasks, which contained 200 task statements, 23 professional issues statements, and 177 clinical conditions, was divided into three equivalent survey forms and distributed to those certified nurse-midwives (CNMs) and certified midwives (CMs) certified by the ACNM Certification Council, Inc. during the 5-year period from 1995 to 1999. Specific efforts were made to encourage the participation of

Sachiko Oshio; Peter Johnson; Judith Fullerton

2002-01-01

240

A CAGE TRAP FOR LIVE-TRAPPING MOUNTAIN LIONS  

Microsoft Academic Search

The use of cage traps to capture mountain lions (Felix concolor) has the potential to become a valuable tool in the USDA-APHIS-ADC program. Because of California public sentiment, many of the traditional methods can no longer be used or are being severely restricted. Due to increasing requests for assistance, California ADC personnel have had to develop a method that will

James D. Shuler

1992-01-01

241

Task Analysis: A Proactive Paradigm.  

ERIC Educational Resources Information Center

A sequential and developmental curriculum design is conceptualized, based on task analysis. Task analysis is a detailed inquiry into actions undertaken in performing specific tasks or jobs. Baseline data form a database on which education and training programs are designed, produced, and evaluated. The following are sources of information for task

Cipriano, Robert E.

242

Skill Components of Task Analysis  

ERIC Educational Resources Information Center

Some task analysis methods break down a task into a hierarchy of subgoals. Although an important tool of many fields of study, learning to create such a hierarchy (redescription) is not trivial. To further the understanding of what makes task analysis a skill, the present research examined novices' problems with learning Hierarchical Task

Adams, Anne E.; Rogers, Wendy A.; Fisk, Arthur D.

2013-01-01

243

Task set switching in schizophrenia  

Microsoft Academic Search

The authors used a task-switching paradigm to investigate set shifting ability in schizophre- nia. This paradigm included 2 choice reaction time (RT) tasks: up--down and right-left. Switching tasks were associated with costs (i.e., longer RT in task-switch trials than in task-repetition trials); patients responded more slowly than controls and suffered greater switching costs, were as efficient as controls in engaging

Nachshon Meiran; Joseph Levine; Naama Meiran; Avishai Henik

2000-01-01

244

Rotational dynamics of optically trapped polymeric nanofibers  

E-print Network

The optical trapping of polymeric nanofibers and the characterization of the rotational dynamics are reported. A strategy to apply a torque to a polymer nanofiber, by tilting the trapped fibers using a symmetrical linear polarized Gaussian beam is demonstrated. Rotation frequencies up to 10 Hz are measured, depending on the trapping power, the fiber length and the tilt angle. A comparison of the experimental rotation frequencies in the different trapping configurations with calculations based on optical trapping and rotation of linear nanostructures through a T-Matrix formalism, accurately reproduce the measured data, providing a comprehensive description of the trapping and rotation dynamics.

Neves, Antonio Alvaro Ranha; Pagliara, Stefano; Saija, Rosalba; Borghese, Ferdinando; Denti, Paolo; Iati, Maria Antonia; Cingolani, Roberto; Marago, Onofrio M; Pisignano, Dario

2010-01-01

245

Surface-electrode point Paul trap  

SciTech Connect

We present a model as well as experimental results for a surface electrode radiofrequency Paul trap that has a circular electrode geometry well suited for trapping single ions and two-dimensional planar ion crystals. The trap design is compatible with microfabrication and offers a simple method by which the height of the trapped ions above the surface may be changed in situ. We demonstrate trapping of single {sup 88}Sr{sup +} ions over an ion height range of 200-1000 {mu}m for several hours under Doppler laser cooling and use these to characterize the trap, finding good agreement with our model.

Kim, Tony Hyun; Herskind, Peter F.; Chuang, Isaac L. [Center for Ultracold Atoms, Department of Physics, Massachusetts Institute of Technology 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Kim, Taehyun; Kim, Jungsang [Department of Electrical and Computer Engineering, Duke University Durham, North Carolina 27708 (United States)

2010-10-15

246

Optical trapping of coated microspheres.  

PubMed

In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm--the trapping laser wavelength in water--and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays. PMID:18772994

Bormuth, Volker; Jannasch, Anita; Ander, Marcel; van Kats, Carlos M; van Blaaderen, Alfons; Howard, Jonathon; Schäffer, Erik

2008-09-01

247

Flux Trapping in Superconducting Circuits  

Microsoft Academic Search

It is widely accepted that flux trapping is one of the most serious problems that could create an integration limit for superconductor integrated circuits. The ultimate goal of our project is to reduce the problem to a set of routine technical recommendations for SFQ circuit design. To achieve the goal, we review known theories and recommendations for the reduction of

Yuri Polyakov; Supradeep Narayana; Vasili K. Semenov

2007-01-01

248

Kinetics of charge trapping in dielectrics  

NASA Astrophysics Data System (ADS)

Transient electronic conduction in thermally grown SiO2 has been shown to be limited by space-charge evolution. The space charge originates from trapping of the injected species. It induces a field which affects the emission of charges at the injecting electrode. The trapping of charge has been analyzed on the basis of three, essentially different, mechanisms: (1) first order trapping, (2) first order trapping which takes into account that trapped charges repel injected charges, and (3) trapping which increases during injection due to the generation of states. It is shown that implementation of the three trapping mechanisms yields a current versus injected charge plot which is given in the asymptotes by simple logarithmic functions. Intersection of the asymptotes directly yields the value of the capture cross section. From the slopes of the asymptotes the surface density(ies) of the trap(s) can be calculated. The method can be used without, a priori, assuming either the injection mechanism or the trapping mechanism. From the relative position of the intersection points the applicable mechanism can be derived, however. For thermal SiO2 on Si we determined, by this method, values of trap densities and capture cross sections which are typical for water-related traps. Furthermore, we derived that trapping mechanism (2) fits our data best.

Wolters, D. R.; van der Schoot, J. J.

1985-07-01

249

Task switching in a hierarchical task structure: evidence for the fragility of the task repetition benefit  

NASA Technical Reports Server (NTRS)

This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms. In Experiments 2-5, adjacent task elements were grouped temporally and/or spatially (forming an ensemble) to create a hierarchical task organization. Results indicate that the effect of switching at the ensemble level dominated the effect of switching at the element level. Experiments 6 and 7, using an ensemble of 3 task elements, revealed that the element-level switch cost was virtually absent between ensembles but was large within an ensemble. The authors conclude that the element-level task repetition benefit is fragile and can be eliminated in a hierarchical task organization.

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

250

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

251

The task force process  

SciTech Connect

This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several {open_quotes}big picture{close_quotes} issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald.

Applegate, J.S. [Univ. of Cincinnati, OH (United States)

1995-01-31

252

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

253

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

254

Quantum mechanics and the equivalence principle  

E-print Network

A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. I conclude with some remarks about the strong equivalence principle in quantum mechanics.

P. C. W. Davies

2004-03-03

255

Accelerating classical charges and the equivalence principle  

E-print Network

We compare the behavior of a charged particle in a gravitational field and empty space. We resolve the apparent conflict between the Lorentz-Dirac equation and Larmor's formula of radiation by noting that the former describes an electron that is itself accelerated by an electromagnetic field. If instead, a hypothetical particle is considered that is accelerated by a non-electromagnetic force, Larmor's formula is found to be consistent with the accelerating particle's equation of motion. We consider the consequences concerning the equivalence principle and find that it is indeed violated if one demands that the same electromagnetic field be present in both the gravitational and accelerating cases; however, if one allows for the external electromagnetic fields to be different, the validity of the equivalence principle is restored. In either case, the basic idea behind the equivalence principle, which leads to a geometrized theory of gravity, remains unaffected.

Viktor T. Toth

2014-04-10

256

Fiber optic integration in planar ion traps  

E-print Network

Atomic ion traps are are excellent tools in atomic physics for studying single ions. Accurate measurement of the ion's electronic state in these ion traps is required by both atomic clocks and quantum computation. Quantum ...

George, Elizabeth Marie

2008-01-01

257

Inertial measurement via dynamics of trapped particles  

E-print Network

We describe theoretical and practical aspects of the particle trap as an inertial sensor. The insight motivating this approach is that a trapped particle acts like a mass on a spring, but the restoring forces are provided ...

Post, E. Rehmi, 1966-

2003-01-01

258

Surface-electrode point Paul trap  

E-print Network

We present a model as well as experimental results for a surface electrode radiofrequency Paul trap that has a circular electrode geometry well suited for trapping single ions and two-dimensional planar ion crystals. The ...

Chuang, Isaac L.

259

Biases in Drosophila melanogaster protein trap screens  

E-print Network

genome, the repertoire of genes that yield protein traps is still small. Results We analysed the collection of available protein trap lines in Drosophila melanogaster and identified potential biases that are likely to restrict genome coverage in protein...

Aleksic, Jelena; Lazic, Ranko; Muller, Ilka; Russell, Steven R; Adryan, Boris

2009-05-28

260

Capturing Energy Savings with Steam Traps  

E-print Network

This paper will discuss the energy savings potential of steam traps and present the energy, economic, and environmental reason why an active steam trap maintenance program is good for the company's bottom line. Several case studies will be discussed...

Bockwinkel, R. G.; French, S. A.

261

50 CFR 31.16 - Trapping program.  

Code of Federal Regulations, 2011 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...

2011-10-01

262

50 CFR 31.16 - Trapping program.  

Code of Federal Regulations, 2012 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...

2012-10-01

263

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

264

50 CFR 31.16 - Trapping program.  

Code of Federal Regulations, 2010 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...

2010-10-01

265

Electrophysiological correlates of stimulus equivalence processes.  

PubMed

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., wrist, corn). For pairs of both types, event-related cortical potentials were recorded during and immediately after the presentation of the second word. The obtained waveforms differentiated these two types of pairs. For the unrelated pairs, the waveforms were significantly more negative about 400 ms after the second word was presented, thus replicating the "N400" phenomenon of the cognitive neuroscience literature. In addition, there was a strong positive-tending wave form difference post-stimulus presentation (peaked at about 500 ms) that also differentiated the unrelated from related stimulus pairs. In Experiment 2, the procedures were extended to study arbitrary stimulus-stimulus relations established via matching-to-sample training. Participants were experimentally naïve adults. Sample stimuli (Set A) were trigrams, and comparison stimuli (Sets B, C, D, E, and F) were nonrepresentative forms. Behavioral tests evaluated potentially emergent equivalence relations (i.e., BD, DF, CE, etc.). All participants exhibited classes consistent with the arbitrary matching training. They were also exposed also to an event-related potential procedure like that used in Experiment 1. Some received the ERP procedure before equivalence tests and some after. Only those participants who received ERP procedures after equivalence tests exhibited robust N400 differentiation initially. The positivity observed in Experiment 1 was absent for all participants. These results support speculations that equivalence tests may provide contextual support for the formation of equivalence classes including those that emerge gradually during testing. PMID:20354602

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

2009-09-01

266

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

267

Collective coherent population trapping in a thermal field  

E-print Network

We analyzed the efficiency of coherent population trapping (CPT) in a superposition of the ground states of three-level atoms under the influence of the decoherence process induced by a broadband thermal field. We showed that in a single atom there is no perfect CPT when the atomic transitions are affected by the thermal field. The perfect CPT may occur when only one of the two atomic transitions is affected by the thermal field. In the case when both atomic transitions are affected by the thermal field, we demonstrated that regardless of the intensity of the thermal field the destructive effect on the CPT can be circumvented by the collective behavior of the atoms. An analytic expression was obtained for the populations of the upper atomic levels which can be considered as a measure of the level of thermal decoherence. The results show that the collective interaction between the atoms can significantly enhance the population trapping in that the population of the upper state decreases with increased number of atoms. The physical origin of this feature was explained by the semiclassical dressed atom model of the system. We introduced the concept of multiatom collective coherent population trapping by demonstrating the existence of collective (entangled) states whose storage capacity is larger than that of the equivalent states of independent atoms.

M. Macovei; Z. Ficek; C. H. Keitel

2006-06-01

268

A Collapsible Trap for Capturing Ruffe  

Microsoft Academic Search

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

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

1998-01-01

269

Microchip-Based Trapped-Atom Clocks  

E-print Network

This is a chapter of a recently published book entitled Atom Chips, edited by Jakob Reichel and Vladan Vuletic. The contents of this chapter include: Basic Principles; Atomic-Fountain versus Trapped-Atom Clocks; Optical-Transition Clocks versus Microwave Clocks; Clocks with Magnetically Trapped Atoms--Fundamental Limits and Experimental Demonstrations; Readout in Trapped-Atom Clocks; and Spin Squeezing.

Vladan Vuletic; Ian D. Leroux; Monika H. Schleier-Smith

2011-04-20

270

Optical trapping for undergraduates D. C. Appleyard  

E-print Network

Optical trapping for undergraduates D. C. Appleyard Department of Biological Engineering September 2006 The detailed design of a robust and inexpensive optical trap system is presented. The system experimental modules are described to cover basic concepts in optical trapping and biophysics at a level

Lang, Matthew

271

Catalytic traps for diesel particulate control  

Microsoft Academic Search

The first stages of the development of a catalytic trap for diesel particulate removal from vehicle exhaust gases are addressed, ranging from catalytic trap preparation (a ceramic foam is deposited with catalysts, suitable for soot combustion, based on mixtures of KCl and different vanadates) to catalytic trap testing in a specific pilot plant (an acetylene burner is used to produce

Guido Saracco; Claudio Badini; Vito Specchia

1999-01-01

272

The Canadian Penning Trap mass spectrometer  

Microsoft Academic Search

The Canadian Penning Trap (CPT) mass spectrometer located at the ATLAS facility of Argonne National Laboratory is an online Penning trap system used for mass measurements of high accuracy on short-lived isotopes. It uses a gas catcher as a novel way to transform radioactive ions efficiently from different sources into cooled beams which are injected into ion traps for further

J. C. Wang; G. Savard; K. S. Sharma; J. A. Clark; Z. Zhou; A. F. Levand; C. Boudreau; F. Buchinger; J. E. Crawford; J. P. Greene; S. Gulick; J. K. P. Lee; G. D. Sprouse; W. Trimble; J. Vaz; B. Z. Zabransky

2004-01-01

273

Learner Mining of Pre-Task and Task Input  

ERIC Educational Resources Information Center

The findings reported in this article suggest that learners inevitably "mine" wordings contained in pre-task and task materials when performing tasks, even when the teacher did not explicitly draw learner attention to these features. However, this was found to be true only with written materials, and learners did not appear to mine specific…

Boston, Jeremy Scott

2008-01-01

274

Task Performance & Eye Activity 1 Task Performance and Eye Activity  

E-print Network

. Conclusion: Eye behavior trends reported in this study may provide insight to human behavior correspondingTask Performance & Eye Activity 1 Task Performance and Eye Activity: Predicting Behavior Relating of California, San Diego, San Diego, CA Running Head: Task Performance & Eye Activity Abstract word count: 254

Makeig, Scott

275

Harrison's criterion, Witt equivalence and reciprocity equivalence N. Grenier-Boley  

E-print Network

Harrison's criterion, Witt equivalence and reciprocity equivalence N. Grenier-Boley February 5, 2006 Abstract. Harrison's criterion characterizes the isomorphy of the Witt rings of two fields- acterizations for the isomorphism of Witt groups of hermitian forms over certain algebras with involution

276

Harrison's criterion, Witt equivalence and reciprocity equivalence N. Grenier-Boley*  

E-print Network

Harrison's criterion, Witt equivalence and reciprocity equivalence's criterion characterizes the isomorphy of the Witt rings o* *f two fields in terms of properties for the isomorphism of Witt groups of hermitian forms over certai* *n algebras with involution. In the cases where

277

Harrison's criterion, Witt equivalence and reciprocity equivalence N. GrenierBoley #  

E-print Network

Harrison's criterion, Witt equivalence and reciprocity equivalence N. Grenier­Boley # February 5, 2006 Abstract. Harrison's criterion characterizes the isomorphy of the Witt rings of two fields­ acterizations for the isomorphism of Witt groups of hermitian forms over certain algebras with involution

278

State primary standards of equivalent dose and equivalent dose rate units of neutron radiation  

Microsoft Academic Search

In 1975, the Gosstandard of the USSR approved the primary standard of equivalent dose and equivalent dose rate units of neutron radiation created in the All-Union Scientific Research Institute of Metrology as primary State standards. In accordance with international recommendations and standards, the degree of radiation hazards to a chronically exposed human being is evaluated with the aid of the

A. P. Yanovskii; M. F. Yudin; L. A. Popruzhko; V. V. Frolov; Yu. D. Lysak

1976-01-01

279

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

280

Effect of trap type, trap color, trapping location, and pheromone dispenser on captures of male Palpita unionalis (Lepidoptera: Pyralidae).  

PubMed

Field studies were conducted to evaluate the influence of trap design, trapping location, type of pheromone dispenser, and trap color on the capture of Palpita unionalis (Hübner) males, in olive groves. The experiments were carried out in two regions, Alexandria (northern Greece) and Oropos (central Greece), where olives are cultivated. In both regions, the majority of the males (> 70% of the total) were caught from late autumn to early winter, whereas < 1% was caught during July and August. Among the trap types used, the Funnel was significantly more attractive than Delta, Pherocon 1C, and Pherocon II traps. More males were caught in traps placed at the periphery of the groves than those placed in the center. Among the four colored traps tested, white traps were the most effective. However, a significant difference in trap catches was found between white and brown traps. Traps baited with red rubber septa captured more males than those baited with the white one. The use of these parameters in monitoring and managing P. unionalis is discussed. PMID:15154451

Athanassiou, Christos G; Kavallieratos, Nickolas G; Mazomenos, Basilios E

2004-04-01

281

Chameleonic equivalence postulate and wave function collapse  

E-print Network

A chameleonic solution to the cosmological constant problem and the non-equivalence of different conformal frames at the quantum level have been recently suggested [Phys. Rev. D82 (2010) 044006]. In this article we further discuss the theoretical grounds of that model and we are led to a chameleonic equivalence postulate (CEP). Whenever a theory satisfies our CEP (and some other additional conditions), a density-dependence of the mass of matter fields is naturally present. Let us summarize the main results of this paper. 1) The CEP can be considered the microscopic counterpart of the Einstein's Equivalence Principle and, hence, a chameleonic description of quantum gravity is obtained: in our model, (quantum) gravitation is equivalent to a conformal anomaly. 2) To illustrate one of the possible applications of the CEP, we point out a connection between chameleon fields and quantum-mechanical wave function collapse. The collapse is induced by the chameleonic nature of the theory. We discuss the collapse for a Stern-Gerlach experiment and for a diffraction experiment with electrons. More research efforts are necessary to verify whether these ideas are compatible with phenomenological constraints.

Andrea Zanzi

2014-04-03

282

Functional Equivalence and Spatial Path Memory  

Microsoft Academic Search

Loomis, Klatzky, Avraamides, Lippa & Golledge (2007) suggest that, when it comes to spatial information, verbal description and perceptual experience are nearly functionally equivalent with respect to the cognitive representations they produce. We tested this idea for the case of spatial memory for complex paths. Paths consisted entirely of unit-length segments followed by 90-degree turns, thus assuring that a path

Don R. Lyon; Glenn M. Gunzelmann

2011-01-01

283

Containment and equivalence for an XPath fragment  

Microsoft Academic Search

XPath is a simple language for navigating an XML document and selecting a set of element nodes. XPath expressions are used to query XML data, describe key constraints, express transformations, and reference elements in remote documents. This paper studies the containment and equivalence problems for a fragment of the XPath query language, with applications in all these contexts.In particular, we

Gerome Miklau; Dan Suciu

2002-01-01

284

Biomonitoring Equivalents for DDT\\/DDE  

Microsoft Academic Search

Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite in a biological medium (blood, urine, or other medium) that is consistent with an existing health-based exposure guideline such as a reference dose (RfD) or tolerable daily intake (TDI). BE values can be used as a screening tool for the evaluation of

Christopher R. Kirman; Lesa L. Aylward; Sean M. Hays; Kannan Krishnan; Andy Nong

2011-01-01

285

Using SAT for combinational equivalence checking  

Microsoft Academic Search

This paper addresses the problem of combinational equivalence checking (CEC) which forms one of the key componentsof the current verification methodology for dig- ital systems. A number of recently proposed BDD based approaches have met with considerable success in this area. However, the growing gap between the capability of current solvers and the complexity of verification instances neces- sitates the

Evguenii I. Goldberg; Mukul R. Prasad; Robert K. Brayton

2001-01-01

286

Using SAT for combinational equivalence checking  

Microsoft Academic Search

This paper addresses the problem of combinational equivalence checking (CEC) which forms one of the key components of the current verification methodology for digital systems. A number of recently proposed BDD based approaches have met with considerable success in this area. However, the growing gap between the capability of current solvers and the complexity of verification instances necessitates the exploration

Evgueni I. Goldberg; Mukul R. Prasad; Robert K. Brayton

2001-01-01

287

Classification and equivalence in estimation theory  

NASA Technical Reports Server (NTRS)

A method is proposed for classifying estimation problems based on the Lie algebra generated by the operators which appear in the conditional density equation. A natural class of automorphisms of this algebra is examined and a systematic method of generating equivalent problems is developed. Finally, a new class of nonlinear filtering problems with essentially nonlinear filtering equations are presented.

Brockett, R. W.

1979-01-01

288

Equivalent Representations in the Learning of Algebra.  

ERIC Educational Resources Information Center

Discusses how students fail to recognize the underlying equivalence when the same set of points is represented by a graph or an equation or a table. Presents activities in which more than one form of representations of the same information are included. (ASK)

Van Dyke, Frances; Craine, Timothy V.

1997-01-01

289

Static modules and equivalences Robert Wisbauer  

E-print Network

Static modules and equivalences Robert Wisbauer Mathematical Institute of the University 40225 D by the functor HomR (P; ). In R-Mod these are the P -static (= P -solvable) modules. In this context properties [20] and Alperin [3] we call these modules P -static. Other names in the literature are re exive (see

Wisbauer, Robert

290

Static modules and equivalences Robert Wisbauer  

E-print Network

Static modules and equivalences Robert Wisbauer Mathematical Institute of the University 40225 D by the functor HomR(P, -). In R-Mod these are the P-static (= P-solvable) modules. In this context properties" under P S HomR(P, -). Following Nauman [20] and Alperin [3] we call these modules P-static. Other names

Wisbauer, Robert

291

Structural and behavioral equivalence of simulation models  

Microsoft Academic Search

It M sometimes desu-able to know when two different discrete-event simulation models are, in some sense, interchangeable; that is, whether or not the two models always have the same output when run under identical experimental conditions. This notion of behavioral equivalence, while conceptually simple, is difficult to define in a manner that is both useful and testable. It is difficult

Enver Yücesan; Lee Schruben

1992-01-01

292

Competitive intelligence: construct exploration, validation and equivalence  

Microsoft Academic Search

Purpose – Little empirical research has been conducted on competitive intelligence (CI). This paper aims to contribute to the quantitative strand of the CI literature by exploring and validating the theoretical constructs of the CI process. Design\\/methodology\\/approach – Data from 601 questionnaires filled out by South African and Flemish exporters were subjected to exploratory factor analysis and construct equivalence analysis

Andrea Saayman; Jaco Pienaar; Patrick de Pelsmacker; Wilma Viviers; Ludo Cuyvers; Marie-Luce Muller; Marc Jegers

2008-01-01

293

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

294

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

295

Equivalent Circuit Modeling of Hysteresis Motors  

Microsoft Academic Search

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

J J Nitao; E T Scharlemann; B A Kirkendall

2009-01-01

296

Guthrie's Problem: New Equivalences and Rapid Reductions  

Microsoft Academic Search

In 1977, Appel and Haken proved that every planar graph is four vertex colourable which finally proved Guthrie's conjecture of circa 1852 that four colours are always sufficient. Their proof is very long and the implicit algorithm for four colouring is rather impractical. This paper provides a new characterisation of the four-colour problem by showing that it is equivalent (by

Artur Czumaj; Alan Gibbons

1996-01-01

297

STRONG SHIFT EQUIVALENCE OF C-CORRESPONDENCES  

E-print Network

STRONG SHIFT EQUIVALENCE OF C-CORRESPONDENCES PAUL S. MUHLY, DAVID PASK, AND MARK TOMFORDE Abstract papers, [23] by R. Williams and [4] by J. Cuntz and W. Krieger. To understand why, suppose A and B] Williams proved that the shift dynamical systems Date: March 20, 2007. 2000 Mathematics Subject

Pask, David

298

Mechanical Equivalent of Heat Virtual Lab  

NSDL National Science Digital Library

This virtual lab simulates the lab in which students repeatedly drop metal shot through a cardboard tube, but without the inaccuracies that often plague the traditional lab. Students first verify the principle of the mechanical equivalence of heat, then use it to calculate the specific heat of different metals. A printable lab guide is included.

2014-04-03

299

Canonical equivalence between massive spin 1 theories  

E-print Network

The model of Cremmer-Scherck and Proca are considered in dimensions greater than 3+1. It is obtained that the Proca model correspond to a gauged fixed version of the Cremmer-Scherck one, and we show their canonical equivalence.

Pio J. Arias; Jean C. Perez-Mosquera

2004-10-20

300

Research Article The Equivalence of Learning  

E-print Network

reasoning associated with the evaluation of science- fair posters. We found not only that many more childrenResearch Article The Equivalence of Learning Paths in Early Science Instruction Effects of Direct children basic procedures for early scientific investigations. A widely accepted claim in the science

Klahr, David

301

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

302

Spin trapping artifacts in DMSO  

SciTech Connect

Spin-trapping experiments in alkaline aqueous dimethyl sulfoxide (DMSO) solution using sodium 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) yielded a strong signal of the sulfur trioxide anion radical adduct. This radical adduct is identical to that obtained by the oxidation of sulfite with horseradish peroxidase/hydrogen peroxide and subsequent spin trapping with DBNBS. This radical adduct is very stable, and satellite peaks of the natural abundance /sup 13/C and /sup 33/S could be obtained. Apparently, under alkaline conditions DMSO decomposes in air to form the sulfur trioxide anion radical. A comparison with a recent publication shows that this DMSO-derived radical adduct has been misassigned as a uniquely stable spin adduct of superoxide.

Stolze, K.; Mason, R.P.

1987-03-30

303

Topological constraints on magnetostatic traps  

SciTech Connect

We theoretically investigate properties of magnetostatic traps for cold atoms that are subject to externally applied uniform fields. We show that Ioffe-Pritchard traps and other stationary points of B are confined to a two-dimensional curved surface, or manifold M, defined by det({partial_derivative}B{sub i}/{partial_derivative}x{sub j})=0. We describe how stationary points can be moved over the manifold by applying external uniform fields. The manifold also plays an important role in the behavior of points of zero field. Field zeroes occur in two distinct types, in separate regions of space divided by the manifold. Pairs of zeroes of opposite type can be created or annihilated on the manifold. Finally, we give examples of the manifold for cases of practical interest.

Gerritsma, R.; Spreeuw, R. J. C. [Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)

2006-10-15

304

Cosmic balls of trapped neutrinos.  

NASA Astrophysics Data System (ADS)

Fermions trapped inside a closed domain wall may cool to degeneracy and form a long-lived structure. In the context of spontaneous left-right symmetry breaking, it is shown that trapped right-handed neutrinos cool due to annihilations to electron-positron pairs if the initial temperature is less than 0.21 me. The surface tension of the wall must be less than (1.93 TeV)3. The lifetime of the neutrino-ball (NB) is determined by neutrino annihilation to three photons and may be comparable to the age of the universe. These NBs are in the 104 - 107 solar mass range and radiate ?-rays in the few hundred keV range at a rate of 1040 - 1043ergs/sec.

Holdom, B.

305

Cosmic balls of trapped neutrinos  

NASA Astrophysics Data System (ADS)

Fermions trapped inside a closed domain wall may cool to degeneracy and form a long-lived structure. In the context of spontaneous left-right-symmetry breaking, we show that trapped right-handed neutrinos cool due to annihilations to electron-positron pairs if the initial temperature is less than 0.21me. The surface tension of the wall must be less than (1.93 TeV)3. The lifetime of the neutrino ball (NB) is determined by neutrino annihilation to three photons and may be comparable to the age of the Universe. These NB's are in the 104-107 solar mass range and radiate ? rays in the few hundred keV range at a rate of 1040-1044 erg/sec range. NB's die in a 1056-1059 erg electron-positron burst.

Holdom, Bob

1987-08-01

306

49 CFR 538.8 - Gallon Equivalents for Gaseous Fuels.  

Code of Federal Regulations, 2010 CFR

...false Gallon Equivalents for Gaseous Fuels. 538.8 Section 538.8 Transportation...TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.8 Gallon Equivalents for Gaseous Fuels. The gallon equivalent of...

2010-10-01

307

EXISTENTIALLY EQUIVALENT CYCLIC ULTRAMETRIC SPACES AND CYCLICALLY VALUED GROUPS.  

E-print Network

EXISTENTIALLY EQUIVALENT CYCLIC ULTRAMETRIC SPACES AND CYCLICALLY VALUED GROUPS. G. LELOUP Abstract we characterize existentially equivalence between cyclically ultrametric spaces, as well as existentially equivalence between generalized ultrametric spaces. We also describe classes of existentially

308

22 CFR 1421.18 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2013 CFR

...Regular and substantially equivalent employment. 1421.18...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2013-04-01

309

5 CFR 2421.17 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2013 CFR

...Regular and substantially equivalent employment. 2421.17...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2013-01-01

310

5 CFR 2421.17 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2012 CFR

...Regular and substantially equivalent employment. 2421.17...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2012-01-01

311

5 CFR 2421.17 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2010 CFR

...Regular and substantially equivalent employment. 2421.17...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2010-01-01

312

22 CFR 1421.18 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2011 CFR

...Regular and substantially equivalent employment. 1421.18...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2011-04-01

313

5 CFR 2421.17 - Regular and substantially equivalent employment.  

...Regular and substantially equivalent employment. 2421.17...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2014-01-01

314

22 CFR 1421.18 - Regular and substantially equivalent employment.  

...Regular and substantially equivalent employment. 1421.18...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2014-04-01

315

5 CFR 2421.17 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2011 CFR

...Regular and substantially equivalent employment. 2421.17...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2011-01-01

316

22 CFR 1421.18 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2010 CFR

...Regular and substantially equivalent employment. 1421.18...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2010-04-01

317

22 CFR 1421.18 - Regular and substantially equivalent employment.  

Code of Federal Regulations, 2012 CFR

...Regular and substantially equivalent employment. 1421.18...Regular and substantially equivalent employment. Regular and substantially equivalent employment means employment...the same amount of work, rate of pay, hours,...

2012-04-01

318

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

319

Cooling Techniques for Trapped Ions  

E-print Network

This book chapter gives an introduction to, and an overview of, methods for cooling trapped ions. The main addressees are researchers entering the field. It is not intended as a comprehensive survey and historical account of the extensive literature on this topic. We present the physical ideas behind several cooling schemes, outline their mathematical description, and point to relevant literature useful for a more in-depth study of this topic.

Segal, Daniel M

2014-01-01

320

Cooling Techniques for Trapped Ions  

E-print Network

This book chapter gives an introduction to, and an overview of, methods for cooling trapped ions. The main addressees are researchers entering the field. It is not intended as a comprehensive survey and historical account of the extensive literature on this topic. We present the physical ideas behind several cooling schemes, outline their mathematical description, and point to relevant literature useful for a more in-depth study of this topic.

Daniel M. Segal; Christof Wunderlich

2014-09-24

321

Extending dark optical trapping geometries  

E-print Network

New counter-propagating geometries are presented for localising ultracold atoms in the dark regions created by the interference of Laguerre-Gaussian laser beams. In particular dark helices, an 'optical revolver,' axial lattices of rings and axial lattices of ring lattices of rings are considered and a realistic scheme for achieving phase-stability is explored. The dark nature of these traps will enable their use as versatile tools for low-decoherence atom interferometry with zero differential light shifts.

Arnold, Aidan S

2012-01-01

322

Extending dark optical trapping geometries.  

PubMed

New counterpropagating geometries are presented for localizing ultracold atoms in the dark regions created by the interference of Laguerre-Gaussian laser beams. In particular dark helices, an "optical revolver," axial lattices of rings, and axial lattices of ring lattices of rings are considered and a realistic scheme for achieving phase stability is explored. The dark nature of these traps will enable their use as versatile tools for low-decoherence atom interferometry with zero differential light shifts. PMID:22743436

Arnold, Aidan S

2012-07-01

323

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

324

Stem Cell Task Force  

NSDL National Science Digital Library

This Web site from the National Institutes of Health (NIH) provides an overview of the activities of an NIH task force established to move the stem cell research agenda forward. The section titled Scientific Research may be of particular interest to researchers in this area. It provides links to the Web sites of stem cell-related research at a number of NIH institutes, as well as an extensive information index, a FAQs page about stem cell research, information on funding opportunities, and much more.

325

Component Processes in Task Switching  

Microsoft Academic Search

Participants switched between two randomly ordered, two-choice reaction-time (RT) tasks, where an instructional cue preceded the target stimulus and indicated which task to execute. Task-switching cost dissipated passively while the participants waited for the instructional cue in order to know which task to execute (during the Response–Cue Interval). Switching cost was sharply reduced, but not abolished, when the participants actively

Nachshon Meiran; Ziv Chorev; Ayelet Sapir

2000-01-01

326

Dynamic modeling of trapped particles  

SciTech Connect

Understanding the dynamics of trapped particles is not simple, because storms are different and not too many satellites are orbiting at the same time with detectors aboard. In the past, general considerations have been made about radial diffusion, sources, and losses but at present, due to the increasing power of computers, new codes can help understand what is really happening to particles during storm periods in the trapped region. Physical considerations about four different codes are presented here. The applications of full trajectory codes, codes using Guiding Center Approximation, three-dimensional diffusion codes, and four-dimensional diffusive-convective codes are given. In the near future, with some of these codes, it seems that a step will be passed in the modeling and comprehension of the physical phenomena occurring during such periods. The authors then will be able to identify the different kinds of storms and their implications on trapped particles, and maybe make some predictions on the fluxes encountered by the satellites in the internal magnetosphere region.

Boscher, D.; Bourdarie, S. [CERT-ONERA, Toulouse (France). Space Technology Dept.] [CERT-ONERA, Toulouse (France). Space Technology Dept.; Beutier, T. [CESR, Toulouse (France)] [CESR, Toulouse (France)

1996-04-01

327

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

328

Simple analytic potentials for linear ion traps  

NASA Technical Reports Server (NTRS)

A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potenital and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency.

Janik, G. R.; Prestage, J. D.; Maleki, L.

1989-01-01

329

Word Fluency: A Task Analysis.  

ERIC Educational Resources Information Center

It is suggested that models of human problem solving are useful in the analysis of word fluency (WF) test performance. In problem-solving terms, WF tasks would require the subject to define and clarify the conditions of the task (task acquisition), select and employ appropriate strategies, and monitor one's performance. In modern neuropsychology,…

Laine, Matti

330

Reverse-Engineering Communication Tasks  

ERIC Educational Resources Information Center

This article introduces an approach to planning sequences of communication tasks that require learners to become personally involved in their learning. By drawing on their own ideas and experiences, as a product of earlier tasks in a given sequence, learners generate the content and resource material on which subsequent tasks operate. The article…

Lamber, Craig

2004-01-01

331

Task-Based Information Searching.  

ERIC Educational Resources Information Center

Reviews studies on the relationship between task performance and information searching by end-users, focusing on information searching in electronic environments and information retrieval systems. Topics include task analysis; task characteristics; search goals; modeling information searching; modeling search goals; information seeking behavior;…

Vakkari, Pertti

2003-01-01

332

Task-oriented rehabilitation robotics.  

PubMed

Task-oriented training is emerging as the dominant and most effective approach to motor rehabilitation of upper extremity function after stroke. Here, the authors propose that the task-oriented training framework provides an evidence-based blueprint for the design of task-oriented robots for the rehabilitation of upper extremity function in the form of three design principles: skill acquisition of functional tasks, active participation training, and individualized adaptive training. The previous robotic systems that incorporate elements of task-oriented trainings are then reviewed. Finally, the authors critically analyze their own attempt to design and test the feasibility of a TOR robot, ADAPT (Adaptive and Automatic Presentation of Tasks), which incorporates the three design principles. Because of its task-oriented training-based design, ADAPT departs from most other current rehabilitation robotic systems: it presents realistic functional tasks in which the task goal is constantly adapted, so that the individual actively performs doable but challenging tasks without physical assistance. To maximize efficacy for a large clinical population, the authors propose that future task-oriented robots need to incorporate yet-to-be developed adaptive task presentation algorithms that emphasize acquisition of fine motor coordination skills while minimizing compensatory movements. PMID:23080042

Schweighofer, Nicolas; Choi, Younggeun; Winstein, Carolee; Gordon, James

2012-11-01

333

Designing Probabilistic Tasks for Kindergartners  

ERIC Educational Resources Information Center

Recent research suggests that children could be engaged in probability tasks at an early age and task characteristics seem to play an important role in the way children perceive an activity. To this direction in the present article we investigate the role of some basic characteristics of probabilistic tasks in their design and implementation. In…

Skoumpourdi, Chrysanthi; Kafoussi, Sonia; Tatsis, Konstantinos

2009-01-01

334

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

335

Principles of Communicative Task Design.  

ERIC Educational Resources Information Center

The use of the learning task as a basic planning and instructional tool for communicative second language instruction is discussed, and considerations and procedures for designing such tasks are outlined. A task is defined as a piece of classroom work that involves learners in comprehending, manipulating, producing, or interacting in the target…

Nunan, David

336

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

337

Ion traps fabricated in a CMOS foundry  

E-print Network

We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This is the first demonstration of scalable quantum computing hardware, in any modality, utilizing a commercial CMOS process, and it opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.

Mehta, K K; Bruzewicz, C D; Chuang, I L; Ram, R J; Sage, J M; Chiaverini, J

2014-01-01

338

The Gloss Trap DAVID STRINGER  

E-print Network

of a machine that did just that, the spraying would still involve a 3D aggregate of psychologically tool, cases continually surface in which syntactic generalizations are made on the basis of assumed the supposedly equivalent combination, this may be held to be a syntactic difference between the two languages

Indiana University

339

Breast composition and radiographic breast equivalence.  

PubMed

The composition of the female breast is an elusive variable in screen-film mammography that has a vital role in determining both the radiographic image quality and breast radiation dose. Despite the large volume of research in mammography only two studies known to the author define the chemical composition of the two major breast constituents, fibrous glandular tissue and adipose tissue. Unfortunately there is not complete agreement between these two studies. Upon this basis, a variety of breast phantom materials have been suggested and developed. This paper examines the radiographic equivalence of some of these materials dealing notably with formulations given by Hammerstein et al and ICRU Report 44, as well as BR12, water, and lucite. Radiographic equivalence was calculated using a computer simulation of mammographic spectra (after the example of Birch and Marshall and Tucker et al, and fitted to available FDA data) applied to attenuation data of phantom materials, in turn based on elemental linear attenuation coefficient data. A software algorithm was written that iteratively calculates the thickness of a nominated material required to match the attenuation of another material of particular thickness. The equivalence of 2-8 cm of lucite to various phantom materials was calculated for molybdenum target, molybdenum filter (Mo/Mo) x-ray beams from 25 to 35 kVp and for Mo/Rh and Rh/Rh beams from 27 to 35 kVp. It was found that for Mo/Mo beams the equivalent thickness of breast phantom material for certain thicknesses of lucite was largely independent of x-ray beam energy with the range of thickness equivalences being less than 3% at 8 cm of lucite and less than 0.5% at 2 cm of lucite. The RMI 156 breast phantom was found to be equivalent to 42 mm of Hammerstein et al. 50% glandular/50% adipose phantom material for Mo/Mo beams at 27 kVp, increasing to 43 mm for the range of Rh/Rh beams. While some questions remain on the accuracy of the present composition of breast constituents, it is clear that various breast compositions can be successfully simulated by using an appropriate thickness of lucite material. The use of lucite breast phantoms is then seen as an effective and reliable way of evaluating mammographic image quality and for calculating breast dose for varying required breast compositions. PMID:9141308

McLean, D

1997-03-01

340

Performance of low pressure tissue equivalent chambers and a new method for parameterizing the dose equivalent  

SciTech Connect

The performance of spherical tissue equivalent chambers with equivalent diameters between 0.5 and 2..mu.. was tested experimentally using monoenergetic and polyenergetic neutron sources in the energy region of 10 keV to 14.5 MeV. Theoretical calculations were performed in order to obtain a simple algorithm for deriving the dose equivalent from the measured data. The algorithm relates the number of recoil particles to the dose equivalent, rather than having a one-to-one correspondence between the lineal energy and the linear energy transfer of the recoil particles. The calculations took into account neutron interactions with hydrogen atoms in the chamber wall as well as in the gas, and also the finite energy resolution determined by both the detector and the electronic system. Qualitatively, the calculations well dscribe the experimental results. The algorithm that was developed determines the neutron dose equivalent, from the data of the 0.5..mu.. chamber, to better than +-20% over the energy range of 30 keV to 14.5 MeV. The same algorithm also determines the dose equivalent from the data of the 2..mu.. chamber to better than +-20% over the energy of 70 keV to 14.5 MeV. The efficiency of the chambers is low and has an average value of 330 counts per mrem, or equivalently about 0.2 c/s per mrem/h. This efficiency enables the measurement of dose equivalent rates only above 100 mrem/h for an integration period of 3 seconds. However, integrated dose equivalents can be mesured as low as 0.1 mrem.

Eisen, Y.; Vasilik, D.G.; Brake, R.J.; Erkkila, B.H.; Littlejohn, G.J.

1986-09-01

341

Task Interpretation and Task Effectiveness: A Vygotskian Analysis of a French L2 Classroom Task.  

ERIC Educational Resources Information Center

This paper focuses on second language (L2) learning through task-based interaction as well as the compatibility of the theories of task-based learning and Vygotsky's sociocultural theory. Language tasks encourage L2 learning by using language as a tool to accomplish a goal. This study analyzes the interaction of first-semester French students…

Myers, Lindsy L.

2000-01-01

342

Whatever gave you that idea? False memories following equivalence training: a behavioral account of the misinformation effect.  

PubMed

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. PMID:22084495

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

2011-11-01

343

The Problem Is Not Learning: Facilitated Acquisition of Stimulus Equivalence Classes among Low-Achieving College Students  

ERIC Educational Resources Information Center

The present study examines whether facilitated acquisition occurs in contexts when 1 stimulus in a class is emotionally evocative and the other stimuli are arbitrary or neutral. Undergraduates with high and low grade-point averages (GPA) completed a matching-to-sample task that resulted in the formation of 3 stimulus equivalence classes. Each…

Adcock, Amanda C.; Merwin, Rhonda M.; Wilson, Kelly G.; Drake, Chad E.; Tucker, Christina I.; Elliott, Camden

2010-01-01

344

Radiation dose equivalent to stowaways in vehicles.  

PubMed

The U.S. Bureau of Customs and Border Protection has deployed a large number of non-intrusive inspection (NII) systems at land border crossings and seaports throughout the United States to inspect cars, trucks, and sea containers. These NII systems use x rays and gamma rays for the detection of contraband. Unfortunately, undocumented aliens infrequently stow away in these same conveyances to illegally enter the United States. It is extremely important that the radiation dose equivalent imparted to these stowaways be within acceptable limits. This paper discusses the issues involved and describes a protocol the U.S. Bureau of Customs and Border Protection has used in a study to measure and document these levels. The results of this study show that the radiation dose equivalent to the stowaways from the deployed NII systems is negligibly small and does not pose a health hazard. PMID:15083143

Khan, Siraj M; Nicholas, Paul E; Terpilak, Michael S

2004-05-01

345

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

346

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

347

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

348

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

349

Einstein's Apple: His First Principle of Equivalence  

E-print Network

After a historical discussion of Einstein's 1907 principle of equivalence, a homogeneous gravitational field in Minkowski spacetime is constructed. It is pointed out that the reference frames in gravitational theory can be understood as spaces with a flat connection and torsion defined through teleparallelism. This kind of torsion was introduced by Einstein in 1928. The concept of torsion is discussed through simple examples and some historical observations.

Engelbert L. Schucking; Eugene J. Surowitz

2007-03-29

350

Kinetic Energy and the Equivalence Principle  

E-print Network

According to the general theory of relativity, kinetic energy contributes to gravitational mass. Surprisingly, the observational evidence for this prediction does not seem to be discussed in the literature. I reanalyze existing experimental data to test the equivalence principle for the kinetic energy of atomic electrons, and show that fairly strong limits on possible violations can be obtained. I discuss the relationship of this result to the occasional claim that ``light falls with twice the acceleration of ordinary matter.''

S. Carlip

1999-09-03

351

Symmetric states: local unitary equivalence via stabilizers  

E-print Network

We classify local unitary equivalence classes of symmetric states via a classification of their local unitary stabilizer subgroups. For states whose local unitary stabilizer groups have a positive number of continuous degrees of freedom, the classification is exhaustive. We show that local unitary stabilizer groups with no continuous degrees of freedom are isomorphic to finite subgroups of the rotation group SO(3), and give examples of states with discrete stabilizers.

Curt D. Cenci; David W. Lyons; Laura M. Snyder; Scott N. Walck

2010-07-22

352

Linear induction motor - Equivalent-circuit model  

Microsoft Academic Search

An equivalent-circuit model of a linear induction motor is developed, using the rotary-motor model as a basis. The rotary-motor model is modified to account for the so-called 'end effect' and is used to predict output thrust, vertical forces and couples. These predictions are checked against test results of a practical motor used on a prototype transit vehicle.

J. Duncan

1983-01-01

353

Task directed sensing  

NASA Technical Reports Server (NTRS)

High-level robot control research must confront the limitations imposed by real sensors if robots are to be controlled effectively in the real world. In particular, sensor limitations make it impossible to maintain a complete, detailed world model of the situation surrounding the robot. To address the problems involved in planning with the resulting incomplete and uncertain world models, traditional robot control architectures must be altered significantly. Task-directed sensing and control is suggested as a way of coping with world model limitations by focusing sensing and analysis resources on only those parts of the world relevant to the robot's active goals. The RAP adaptive execution system is used as an example of a control architecture designed to deploy sensing resources in this way to accomplish both action and knowledge goals.

Firby, R. James

1990-01-01

354

Financial Action Task Force  

NSDL National Science Digital Library

Created in 1989, the Financial Action Task Force (FATF) is an inter-governmental body whose purpose is "the development and promotion of national and international policies to combat money laundering and terrorist financing." Users who are new to the site can get started quickly by looking over the "Quick Links" section on the right-hand side of the homepage. Here they will find a handbook that details how the FATF creates its profiles, information on the methodology, and primary recommendations for creating a coherent set of counter-measures against money laundering. Also, the site includes a "Publications" area, which contains short summaries of reports, along with annual reports dating from 1990 and newsletters from 2007. Finally, the site also contains a listing of recent news items and upcoming events and conferences sponsored by the FATF.

355

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

356

AMU NEXRAD Exploitation Task  

NASA Technical Reports Server (NTRS)

This report documents the results of the Applied Meteorology Unit's NEXRAD Exploitation Task. The objectives of this task are to determine what radar signatures are present prior to and at the time of convection initiation, and to determine radar signatures which will help distinguish whether the ensuing convection will become severe. Radar data from the WSR-88D radar located at NWS Melbourne (WSR-88D/KMLB) were collected between June and September 1995, and 16 convective case studies were analyzed for which the radar was operating during the entire period of interest. All WSR-88D/KMLB products were scrutinized for their utility in detecting convection initiation and severe storm signatures. Through process of elimination, it was found that the 0.5 deg reflectivity product with the lowest reflectivity values displayed is the best product to monitor for convection initiation signatures. Seven meteorological features associated with the initiation of deep convection were identified: the Merritt Island and Indian River convergence zones, interlake convergence, horizontal convective rolls, the sea breeze, storm outflow boundaries, and fires. Their reflectivity values ranged from -5 to 20 dBZ. Of the three severe weather phenomena (winds greater than or equal to 50 kts, tornado, 3/4 inch hail), high wind events due to microbursts were most common in the data set. It was found that the values and trends of composite reflectivity, vertically integrated liquid, and core aspect ratio were key indicators of the potential of a cell to produce a microburst. The data were not analyzed for the other two severe weather phenomena because they rarely occurred during the data collection period. This report also includes suggestions for new WSR-88D products, summaries of ongoing research aimed at creating new products, and explicit recommended procedures for detecting convection initiation and severe storm signatures in the radar data using the currently available technology.

Lambert, Winifred C.; Wheeler, Mark M.

1997-01-01

357

TNT equivalency of M10 propellant  

NASA Technical Reports Server (NTRS)

Peak, side-on blast overpressure and scaled, positive impulse have been measured for M10 single-perforated propellant, web size 0.018 inches, using configurations that simulate the handling of bulk material during processing and shipment. Quantities of 11.34, 22.7, 45.4, and 65.8 kg were tested in orthorhombic shipping containers and fiberboard boxes. High explosive equivalency values for each test series were obtained as a function of scaled distance by comparison to known pressure, arrival time and impulse characteristics for hemispherical TNT surface bursts. The equivalencies were found to depend significantly on scaled distance, with higher values of 150-100 percent (pressure) and 350-125 percent (positive impulse) for the extremes within the range from 1.19 to 3.57 m/cube root of kg. Equivalencies as low as 60-140 percent (pressure) and 30-75 percent (positive impulse) were obtained in the range of 7.14 to 15.8 m/cube root of kg. Within experimental error, both peak pressure and positive impulse scaled as a function of charge weight for all quantities tested in the orthorhombic configuration.

Mcintyre, F. L.; Price, P.

1978-01-01

358

Dioxin equivalency: Challenge to dose extrapolation  

SciTech Connect

Extensive research has shown that all biological effects of dioxin-like agents are mediated via a single biochemical target, the Ah receptor (AhR), and that the relative biologic potencies of such agents in any given system, coupled with their exposure levels, may be described in terms of toxic equivalents (TEQ). It has also shown that the TEQ sources include not only chlorinated species such as the dioxins (PCDDs), PCDFs, and coplanar PCBs, but also non-chlorinated substances such as the PAHs of wood smoke, the AhR agonists of cooked meat, and the indolocarbazol (ICZ) derived from cruciferous vegetables. Humans have probably had elevated exposures to these non-chlorinated TEQ sources ever since the discoveries of fire, cooking, and the culinary use of Brassica spp. Recent assays of CYP1A2 induction show that these ``natural`` or ``traditional`` AhR agonists are contributing 50--100 times as much to average human TEQ exposures as do the chlorinated xenobiotics. Currently, the safe doses of the xenobiotic TEQ sources are estimated from their NOAELs and large extrapolation factors, derived from arbitrary mathematical models, whereas the NOAELs themselves are regarded as the safe doses for the TEQs of traditional dietary components. Available scientific data can neither support nor refute either approach to assessing the health risk of an individual chemical substance. However, if two substances be toxicologically equivalent, then their TEQ-adjusted health risks must also be equivalent, and the same dose extrapolation procedure should be used for both.

Brown, J.F. Jr.; Silkworth, J.B. [GE Corporate Research and Development, Schenectady, NY (United States)

1995-12-31

359

Determining sample size when assessing mean equivalence.  

PubMed

Abstract Background. When we want to assess whether two analytical methods are equivalent, we could test if the difference between the mean results is within the specification limits of 0 ± an acceptance criterion. Testing the null hypothesis of zero difference is less interesting, and so is the sample size estimation based on testing that hypothesis. Power function curves for equivalence testing experiments are not widely available. In this paper we present power function curves to help decide on the number of measurements when testing equivalence between the means of two analytical methods. Methods. Computer simulation was used to calculate the probability that the 90% confidence interval for the difference between the means of two analytical methods would exceed the specification limits of 0 ± 1, 0 ± 2 or 0 ± 3 analytical standard deviations (SDa), respectively. Results. The probability of getting a nonequivalence alarm increases with increasing difference between the means when the difference is well within the specification limits. The probability increases with decreasing sample size and with smaller acceptance criteria. We may need at least 40-50 measurements with each analytical method when the specification limits are 0 ± 1 SDa, and 10-15 and 5-10 when the specification limits are 0 ± 2 and 0 ± 3 SDa, respectively. Conclusions. The power function curves provide information of the probability of false alarm, so that we can decide on the sample size under less uncertainty. PMID:25228313

Asberg, Arne; Solem, Kristine B; Mikkelsen, Gustav

2014-11-01

360

Orientifold Planar Equivalence: The Chiral Condensate  

E-print Network

The recently introduced orientifold planar equivalence is a promising tool for solving non-perturbative problems in QCD. One of the predictions of orientifold planar equivalence is that the chiral condensates of a theory with $N_f$ flavours of Dirac fermions in the symmetric (or antisymmetric) representation and $N_f$ flavours of Majorana fermions in the adjoint representation have the same large $N$ value for any value of the mass of the (degenerate) fermions. Assuming the invariance of the theory under charge conjugation, we prove this statement on the lattice for staggered quenched condensates in SU($N$) Yang-Mills in the large $N$ limit. Then, we compute numerically those quenched condensates for $N$ up to 8. After separating the even from the odd corrections in $1/N$, we are able to show that our data support the equivalence; however, unlike other quenched observables, subleading terms in $1/N$ are needed for describing the data for the symmetric and antisymmetric representation at $N$=3. Possible lessons for the unquenched case are discussed.

Adi Armoni; Biagio Lucini; Agostino Patella; Claudio Pica

2008-09-29

361

War and the demographic trap.  

PubMed

Advice is offered on alleviating environmental damage and the suffering of women and children from the effects of war. It is postured that the demographic trap, which was described by King and Elliott, is responsible for environmental stress and many wars. The surface cause may be identified as ideology, politics, or ethnicity, but as in the case of Bosnia, the "ethnic cleansing" makes farmland available to sustain expanding Serbian or Croatian populations. If the land is environmentally damaged by war, then there is little hope of sustainable development. Conflicts in many countries have driven people to urban areas or periurban slums because of displacement and the failure of subsistence economics. Mortality from wars has reached more than a 100 million since the early 1990s. A comparable number have died indirectly from famine and disease associated with the disruption of agriculture and infrastructure from wars. Since 1945, 66-75% of mortality victims have been civilians, of whom 15 million have been women and children. In 1993, there were at least 30 conflicts ongoing throughout the world. Not all of these conflicts are as "ferocious" as the Bosnian conflict, but these "so called low intensity wars" nonetheless disrupt and kill. The manifestations of the demographic trap can be alleviated through interventions that focus on multisectoral aid and conflict resolution. There must be a cooperative effort on the part of health workers, agricultural scientists, mediators, and development personnel. Unfortunately, the amount of development assistance from Europe and America has been reduced in recent years. The recession has affected the provision of international aid. African nations, in particular, have been affected, yet these countries remain the neediest in the world. It would appear that aid agencies have given up hope that the demographic trap can be closed. Population growth must be limited, as the only hope for relieving environmental stress, ecological collapse, and demographic entrapment. The challenge of reducing population must be recognized, and has been recognized by the Union of Concerned Scientists. PMID:8102662

Last, J M

1993-08-28

362

Portable Pbars, traps that travel  

SciTech Connect

The advent of antiproton research utilizing relatively small scale storage devices for very large numbers of these particles opens the possibility of transporting these devices to a research site removed from the accelerator center that produced the antiprotons. Such a portable source of antiprotons could open many new areas of research and make antiprotons available to a new research community. At present antiprotons are available at energies down to 1 MeV. From a portable source these particles can be made available at energies ranging from several tens of kilovolts down to a few millielectron volts. These low energies are in the domain of interest to the atomic and condensed matter physicist. In addition such a source can be used as an injector for an accelerator which could increase the energy domain even further. Moreover, the availability of such a source at a university will open research with antiprotons to a broader range of students than possible at a centralized research facility. This report focuses on the use of ion traps, in particular cylindrical traps, for the antiproton storage device. These devices store the charged antiprotons in a combination of electric and magnet fields. At high enough density and low enough temperature the charged cloud will be susceptible to plasma instabilities. Present day ion trap work is just starting to explore this domain. Our assessment of feasibility is based on what could be done with present day technology and what future technology could achieve. We conclude our report with a radiation safety study that shows that about 10/sup 11/ antiprotons can be transported safely, however the federal guidelines for this transport must be reviewed in detail. More antiprotons than this will require special transportation arrangements. 28 refs., 8 figs.

Howe, S.D.; Hynes, M.V.; Picklesimer, A.

1987-10-01

363

Unconscious task set priming with phonological and semantic tasks.  

PubMed

Whether unconscious stimuli can modulate the preparation of a cognitive task is still controversial. Using a backward masking paradigm, we investigated whether the modulation could be observed even if the prime was made unconscious in 100% of the trials. In two behavioral experiments, subjects were instructed to initiate a phonological or semantic task on an upcoming word, following an explicit instruction and an unconscious prime. When the SOA between prime and instruction was sufficiently long (84 ms), primes congruent with the task set instruction led to speedier responses than incongruent primes. In the other condition (36 ms), no task set priming was observed. Repetition priming had the opposite tendency, suggesting the observed task set facilitation cannot be ascribed solely to perceptual repetition priming. Our results therefore confirm that unconscious information can modulate cognitive control for currently active task sets, providing sufficient time is available before the conscious decision. PMID:23558083

Weibel, Sébastien; Giersch, Anne; Dehaene, Stanislas; Huron, Caroline

2013-06-01

364

Superalgebras for the Penning Trap  

E-print Network

The hamiltonian describing a single fermion in a Penning trap is shown to be supersymmetric in certain cases. The supersymmetries of interest occur when the ratio of the cyclotron frequency to the axial frequency is 3/2 and the particle has anomalous magnetic moment 4/3 or 2/3. At these supersymmetric points, the spectrum shows uniformly spaced crossed levels. The associated superalgebras are su(2|1) and su(1|1). The phase space for this problem has an osp(2|6) structure and contains all the degeneracy superalgebras.

Neil Russell

2001-05-14

365

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

366

Highly scaled charge-trapping layer of ZrON nonvolatile memory device with good retention  

NASA Astrophysics Data System (ADS)

We have fabricated the TaN-[SiO2-LaAlO3]-ZrON-[LaAlO3-SiO2]-Si charge-trapping flash device with highly scaled 3.6 nm equivalent-Si3N4-thickness. This device shows large 4.9 V initial memory window, and good retention of 3.4 V ten-year extrapolated retention window at 85 °C, under very fast 100 ?s and low ±16 V program/erase. These excellent results were achieved using deep traps formed in ZrON trapping layer by As+ implantation that was significantly better than those of control device without ion implantation.

Tsai, C. Y.; Lee, T. H.; Cheng, C. H.; Chin, Albert; Wang, Hong

2010-11-01

367

Trapping radioactive ^{82}Rb in an optical dipole trap and evidence of spontaneous spin polarization  

E-print Network

Optical trapping of selected species of radioactive atoms has great potential in precision measurements for testing fundamental physics such as EDM, PNC and parity violating beta-decay asymmetry correlation coefficients. We report trapping of 10^4 radioactive ^{82}Rb atoms (t_{1/2}=75 s) with a trap lifetime of ~55 seconds in an optical dipole trap. Transfer efficiency from the magneto-optical trap was ~14%. We further report the evidence of spontaneous spin polarization of the atoms in optical dipole trap loading. This advancement is an important step towards a new generation of precision J-beta correlations measurements with polarized ^{82}Rb atoms.

D. Feldbaum; H. Wang; J. Weinstein; D. Vieira; X. Zhao

2007-08-28

368

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

369

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

370

Hydrogen-Trapping Mechanisms in Nanostructured Steels  

NASA Astrophysics Data System (ADS)

Nanoprecipitation-hardened martensitic bearing steels (100Cr6) and carbide-free nanobainitic steels (superbainite) are examined. The nature of the hydrogen traps present in both is determined via the melt extraction and thermal desorption analysis techniques. It is demonstrated that 100Cr6 can admit large amounts of hydrogen, which is loosely bound to dislocations around room temperature; however, with the precipitation of fine coherent vanadium carbide traps, hydrogen can be immobilized. In the case of carbide-free nanostructured bainite, retained austenite/bainite interfaces act as hydrogen traps, while concomitantly retained austenite limits hydrogen absorption. In nanostructured steels where active hydrogen traps are present, it is shown that the total hydrogen absorbed is proportional to the trapped hydrogen, indicating that melt extraction may be employed to quantify trapping capacity.

Szost, B. A.; Vegter, R. H.; Rivera-Díaz-del-Castillo, Pedro E. J.

2013-10-01

371

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

372

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

373

Steam Trap Maintenance as a Profit Center  

E-print Network

with the challenge of upgrading their trap maintenance program: ? "Our maintenance people just fix the traps as they go bad. You can't get any better than this." ? "Operating this plant at a profit is job one. Steam trap maintenance is pretty far down... management directive to the right person with the words, "Do it." JUMP START Steam traps are always going bad and are always being repaired or replaced. This is a fact of life. The key is to keep the time lag between failure and corrective maintenance...

Bouchillon, J. L.

374

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

375

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

376

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

377

Gravitational leptogenesis, C, CP and strong equivalence  

E-print Network

The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

McDonald, J I

2014-01-01

378

The transfer of contextual control over equivalence classes through equivalence classes: a possible model of social stereotyping.  

PubMed Central

In Experiment 1, subjects acquired conditional equivalence classes controlled by three male and three female names as contextual stimuli. When equivalence relations were tested using new names not used in training (three male and three female), contextual control remained intact. Thus, generalized control of the composition of conditional equivalence classes by characteristically gender-identified names was shown. A basic analysis of this finding was tested in Experiment 2. Contextual equivalence classes were established using as contextual stimuli nonrepresentational visual figures that were members of additional pretrained three-member equivalence classes. When other stimuli in the pretrained equivalence classes were used as contextual stimuli, the conditional equivalence classes remained intact. Control subjects showed that this effect depended on the equivalence relations established in pretraining. The results show that contextual control over equivalence classes can transfer through equivalence classes. The implications of this phenomenon for social stereotyping are discussed. PMID:1774542

Kohlenberg, B S; Hayes, S C; Hayes, L J

1991-01-01

379

Dielectric Breakdown and Charge Trapping of Ultrathin ZrHfO/SiON High-k Gate Stacks  

NASA Astrophysics Data System (ADS)

One- and two-step breakdown phenomena were observed on the zirconium-doped hafnium oxide (ZrHfO) high-k dielectric films with equivalent oxide thicknesses 1.8 and 2.5 nm, respectively. The difference in the breakdown sequence was attributed to the bulk high-k layer thickness and interface layer structure. The trap generation and charge trapping in the high-k stack was investigated using a new stress-relax method through analyzing the relaxation current change. The results showed that new traps were only created under the high bias condition and the density could be comparable to or even larger than that of the preexisted traps.

Wan, Rui; Yan, Jiong; Kuo, Yue; Lu, Jiang

2008-03-01

380

TaskArchitect: taking the work out of task analysis  

Microsoft Academic Search

This paper takes a pragmatic approach to the design of a task analysis support tool. Instead of proposing a new approach to analysis, it looks at the common requirements for providing support to a wide range of task analysis practitioners, each applying their own style of analysis. The paper describes the range of activities undertaken when practicing what is commonly

Jon Stuart; Richard Penn

2004-01-01

381

Caffeine improves anticipatory processes in task switching  

Microsoft Academic Search

We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e.g. AB) compared to task-repeat trials (e.g. BB); mixing costs refer to longer RTs in task-repeat

Zoë Tieges; Jan Snel; Albert Kok; Jasper G. Wijnen; Monicque M. Lorist; K. Richard Ridderinkhof

2006-01-01

382

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

383

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

384

Muscle activation and time to task failure differ with load type and contraction intensity for a human hand muscle  

Microsoft Academic Search

Time to failure for sustained isometric contractions of the elbow flexors is briefer when maintaining a constant elbow angle\\u000a while supporting an inertial load (position task) compared with exerting an equivalent torque against a rigid restraint (force\\u000a task). Our primary purpose was to determine whether the effects of load type on time to task failure exist when motor unit\\u000a recruitment

Katrina S. Maluf; Minoru Shinohara; Jennifer L. Stephenson; Roger M. Enoka

2005-01-01

385

Time to task failure and muscle activation vary with load type for a submaximal fatiguing contraction with the lower leg  

Microsoft Academic Search

ABSTRACT The purpose was to compare the time to failure and muscle activation patterns for a sustained isometric submaximal,contraction with the dorsiflexor muscles when the foot was restrained to a force transducer (force task) compared,with supporting an equivalent inertial load and unrestrained (position task). Fifteen men and women,(mean ± SD; 21.1 ± 1.4 years) performed the force and position tasks

Sandra K. Hunter; Tejin Yoon; Joseph Farinella; Erin E. Griffith; Alexander V. Ng

2008-01-01

386

Bosonic Molecules in Rotating Traps  

SciTech Connect

We present a variational many-body wave function for repelling bosons in rotating traps, focusing on rotational frequencies that do not lead to restriction to the lowest Landau level. This wave function incorporates correlations beyond the Gross-Pitaevskii (GP) mean-field approximation, and it describes rotating boson molecules (RBMs) made of localized bosons that form polygonal-ring-like crystalline patterns in their intrinsic frame of reference. The RBMs exhibit characteristic periodic dependencies of the ground-state angular momenta on the number of bosons in the polygonal rings. For small numbers of neutral bosons, the RBM ground-state energies are found to be always lower than those of the corresponding GP solutions, in particular, in the regime of GP vortex formation.

Romanovsky, Igor; Yannouleas, Constantine; Baksmaty, Leslie O.; Landman, Uzi [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States)

2006-09-01

387

Trapping of propelled colloidal particles  

E-print Network

A trapping mechanism for propelled colloidal particles based on an inhomogeneous drive is presented and studied analytically as well as by computer simulations. In experiments this method can be realized using photophoretic Janus particles driven by a light source, which shines through a shading mask and leads to an accumulation of the particles in the shaded part. In an overdamped scenario for colloidal particles, valid for self-propelled particles like microswimmers, the shading causes an inhomogeneous diffusion constant which results in accumulation. For propelled colloidal particles with a finite mass inertia causes a finite penetration depth of particles impinging from the illuminated part of the system into the shaded part, which increases accumulation.

Martin P. Magiera; Lothar Brendel

2014-07-03

388

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

389

Task Modelling in Collective Robotics  

Microsoft Academic Search

Does coherent collective behaviour require an explicit mechanism of cooperation? In this paper, we demonstrate that a certain class of cooperative tasks, namely coordinated box manipulation, are possible without explicit communication or cooperation mechanisms. The approach relies on subtask decomposition and sensor preprocessing. A framework is proposed for modelling multi-robot tasks which are described as a series of steps with

C. Ronald Kube

1997-01-01

390

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.

391

TASK: Anarchy in the Artroom  

ERIC Educational Resources Information Center

Most teenagers do not really like to be told what to do. For that matter, most adults don't either. This article discusses contemporary artist Oliver Herring's TASK, which is an opportunity for participants to bend or define the rules on their own terms. It is about choice, and, for many, it is a dream come true. TASK is controlled chaos that can…

Schubert, Cynthia; Van Patten, Kelda

2012-01-01

392

Task Switching: A PDP Model  

Microsoft Academic Search

When subjects switch between a pair of stimulus–response tasks, reaction time is slower on trial N if a different task was performed on trial N ? 1. We present a parallel distributed processing (PDP) model that simulates this effect when subjects switch between word reading and color naming in response to Stroop stimuli. Reaction time on “switch trials” can be

Sam J. Gilbert; Tim Shallice

2002-01-01

393

Task Switching: A PDP Model  

ERIC Educational Resources Information Center

When subjects switch between a pair of stimulus-response tasks, reaction time is slower on trial N if a different task was performed on trial N--1. We present a parallel distributed processing (PDP) model that simulates this effect when subjects switch between word reading and color naming in response to Stroop stimuli. Reaction time on "switch…

Gilbert, Sam J.; Shallice, Tim

2002-01-01

394

Ecosystem Task Force Meeting Minutes  

E-print Network

Ecosystem Task Force Meeting Minutes Date: April 28, 2011 Title of Meeting: Monthly Meeting. A focus on planning helps ground the Task Force because of the complexity of ecosystems. UNH-862-0785 sustainability.info@unh.edu http://www.sustainableunh.unh.edu/ #12;3.1. Ecosystem work has no defined parameters

New Hampshire, University of

395

Decision paths in complex tasks  

NASA Technical Reports Server (NTRS)

Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

Galanter, Eugene

1991-01-01

396

Task partitioning in insect societies  

Microsoft Academic Search

Summary: Task partitioning is the name given to the phenomenon in which a piece of work is divided among two or more workers, such as the partitioning of the collection of a load of forage between a forager and a storer or transporter. This study 1) reviews empirical data concerning the occurrence of task partitioning in insect societies with the

F. L. W. Ratnieks; C. Anderson

1999-01-01

397

Service Excellence Task Force Report.  

ERIC Educational Resources Information Center

A task force was appointed to measure user satisfaction with library services, establish a university libraries' service excellence philosophy and policy, bring the service excellence concept to the attention of every library employee, and recommend approaches for recognizing outstanding staff service. The members of the task force--two library…

State Univ. of New York, Buffalo. Univ. Libraries.

398

Local unitary versus local Clifford equivalence of stabilizer states  

E-print Network

We study the relation between local unitary (LU) equivalence and local Clifford (LC) equivalence of stabilizer states. We introduce a large subclass of stabilizer states, such that every two LU equivalent states in this class are necessarily LC equivalent. Together with earlier results, this shows that LC, LU and SLOCC equivalence are the same notions for this class of stabilizer states. Moreover, recognizing whether two given stabilizer states in the present subclass are locally equivalent only requires a polynomial number of operations in the number of qubits.

M. Van den Nest; J. Dehaene; B. De Moor

2004-11-16

399

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. PMID:22563424

Huang, Tsung-Ren; Watanabe, Takeo

2012-01-01

400

Cryptography, Quantum Computation and Trapped Ions  

E-print Network

The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

Richard J. Hughes

1997-12-23

401

Oxford ion-trap quantum computing project.  

PubMed

We describe recent progress in the development of an ion-trap quantum information processor. We discuss the choice of ion species and describe recent experiments on read-out for a ground-state qubit and photoionization trap loading. PMID:12869316

Lucas, D M; Donald, C J S; Home, J P; McDonnell, M J; Ramos, A; Stacey, D N; Stacey, J-P; Steane, A M; Webster, S C

2003-07-15

402

Black holes as trapping horizons Eric Gourgoulhon  

E-print Network

Black holes as trapping horizons Eric Gourgoulhon Laboratoire Univers et Th´eories (LUTH) CNRS://www.luth.obspm.fr/~luthier/gourgoulhon/ Centrum Astronomiczne im. M. Kopernika Warsaw, Poland 17 November 2008 Eric Gourgoulhon (LUTH) Black holes as trapping horizons CAMK, Warsaw, 17 Nov. 2008 1 / 36 #12;Plan 1 Local approaches to black holes 2 Viscous

Gourgoulhon, Eric

403

Microscopic flow measurements with optically trapped microprobes  

Microsoft Academic Search

The use of optical tweezers to measure micrometer-resolution velocity fields in f luid f low is demonstrated as an extension of a scanning confocal viscosity microscope. This demonstration is achieved by detection of the motion of an optically trapped microsphere in an oscillating laser trap. The technique is validated by comparison with an independent video-based measurement and applied to obtain

Boaz A. Nemet; Mark Cronin-Golomb

2002-01-01

404

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

405

Ion stochastic trapping and drift turbulence evolution.  

PubMed

Test modes on turbulent magnetized plasmas are studied taking into account the stochastic ion trapping or eddying that characterizes the E×B drift in the background turbulence. It is shown that ion trapping provides an important physical mechanism for the complex nonlinear processes in drift turbulence evolution: generation of large-scale correlations and of zonal flow modes. PMID:23767641

Vlad, Madalina

2013-05-01

406

Cryptography, quantum computation and trapped ions  

SciTech Connect

The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

Hughes, Richard J.

1998-03-01

407

Virus population extinction via ecological traps  

Microsoft Academic Search

Populations are at risk of extinction when unsuitable or when sink habitat exceeds a threshold frequency in the environment. Sinks that present cues associated with high- quality habitats, termed ecological traps, have especially detrimental effects on net population growth at metapopulation scales. Ecological traps for viruses arise naturally, or can be engineered, via the expression of viral-binding sites on cells

John J. Dennehy; Nicholas A. Friedenberg; Yul W. Yang; Paul E. Turner

2007-01-01

408

Curvature estimates for stable marginally trapped surfaces  

E-print Network

We derive integral and sup-estimates for the curvature of stably marginally outer trapped surfaces in a sliced space-time. The estimates bound the shear of a marginally outer trapped surface in terms of the intrinsic and extrinsic curvature of a slice containing the surface. These estimates are well adapted to situations of physical insterest, such as dynamical horizons.

Lars Andersson; Jan Metzger

2005-12-19

409

A NEW TRAPPING TECHNIQUE FOR BURROWING OWLS  

Microsoft Academic Search

A technique to trap ground dwelling owls, using monofilament nooses and wood- en dowel rods, was developed. Setting noose rods does not require modification or disturbance to the burrow and the trap can easily be customized to fit different physical configurations of a burrow or mound. Using this technique permitted capture of 100% of Burrowing Owls (Athene cunicularia) during the

NOOSE ROD; CLARK S. WINCHELL; JOHN W. TUftMAN

410

Ion Trap in a Semiconductor Chip  

E-print Network

The electromagnetic manipulation of isolated atoms has led to many advances in physics, from laser cooling and Bose-Einstein condensation of cold gases to the precise quantum control of individual atomic ion. Work on miniaturizing electromagnetic traps to the micrometer scale promises even higher levels of control and reliability. Compared with 'chip traps' for confining neutral atoms, ion traps with similar dimensions and power dissipation offer much higher confinement forces and allow unparalleled control at the single-atom level. Moreover, ion microtraps are of great interest in the development of miniature mass spectrometer arrays, compact atomic clocks, and most notably, large scale quantum information processors. Here we report the operation of a micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor micro-electromechanical systems (MEMS) technology. We confine, laser cool, and measure heating of a single 111Cd+ ion in an integrated radiofrequency trap etched from a doped gallium arsenide (GaAs) heterostructure.

D. Stick; W. K. Hensinger; S. Olmschenk; M. J. Madsen; K. Schwab; C. Monroe

2006-01-09

411

New vanadium trap proven in commercial trials  

SciTech Connect

A vanadium trap technology called RV4+ has demonstrated in a variety of commercial fluid catalytic cracking (FCC) units its ability to reduce vanadium on equilibrium catalyst by more than 20%. Reducing vanadium loading increases microactivity and zeolite surface area retention, confirming that RV4+ protects zeolites from vanadium deactivation. Sulfur competition had prevented some previous traps from working commercially, but was not a factor with the new trap. The technology can save refiners millions of dollars per year in catalyst costs, or allow them to process feeds containing higher vanadium concentrations. The paper discusses vanadium traps, deactivation mechanism, history of traps, vanadium mobility, intraparticle mobility, interparticle mobility, measuring performance, commercial results, sulfur competition, and economic value.

Dougan, T.J. (Grace Davison, Baltimore, MD (United States)); Alkemade, U.; Lakhanpal, B. (Grace Davison, Worms (Germany)); Boock, L.T. (Grace Davison, Columbia, MD (United States))

1994-09-26

412

Trapping atoms using nanoscale quantum vacuum forces.  

PubMed

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. PMID:25008119

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

2014-01-01

413

Magnetic trapping of cold bromine atoms.  

PubMed

Magnetic trapping of bromine atoms at temperatures in the millikelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br2 molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are lost only by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential. PMID:24484005

Rennick, C J; Lam, J; Doherty, W G; Softley, T P

2014-01-17

414

Magnetic Trapping of Cold Bromine Atoms  

E-print Network

Magnetic trapping of bromine atoms at temperatures in the milliKelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br$_2$ molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are only lost by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential...

Rennick, C J; Doherty, W G; Softley, T P

2014-01-01

415

Micro-fabricated stylus ion trap.  

PubMed

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, (25)Mg(+) 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. PMID:24007096

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

416

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. PMID:22859569

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

2012-01-01

417

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. PMID:25008119

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

2014-01-01

418

Standard Model tests with trapped radioactive atoms  

E-print Network

We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating electric dipole moments can be improved.

J. A. Behr; G. Gwinner

2008-10-22

419

Trap characterization of silicon nitride thin films by a modified trap spectroscopy technique  

NASA Astrophysics Data System (ADS)

Energy levels of traps in silicon nitride are determined using a modified trap spectroscopy method, based on filling of traps using electrical stress followed by optical detrapping, in a metal-silicon nitride-silicon structure. Indium tin oxide with 84% transmittance is used as transparent electrode. Photon energy dependent shift in the flat band voltage is used to estimate type and energetic position of the traps. Here, we report detection of two prominent hole trap levels at 0.5 and 1.1 eV above the valance band edge. The study suggests that phonons hardly participate in the detrapping process of holes in Si3N4.

Midya, Kousik; Dhar, Subhabrata; Kottantharayil, Anil

2013-10-01

420

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

421

The solar test of the equivalence principle  

E-print Network

The Earth, Mars, Sun, Jupiter system allows for a sensitive test of the strong equivalence principle (SEP) which is qualitatively different from that provided by Lunar Laser Ranging. Using analytic and numerical methods we demonstrate that Earth-Mars ranging can provide a useful estimate of the SEP parameter \\eta. Two estimates of the predicted accuracy are derived and quoted, one based on conventional covariance analysis, and another (called ``modified worst case'' analysis) which assumes that systematic errors dominate the experiment. If future Mars missions provide ranging measurements with an accuracy of \\sigma meters, after ten years of ranging the expected accuracy for the SEP parameter \\eta will be of order (1-12)\\times 10^{-4}\\sigma. These ranging measurements will also provide the most accurate determination of the mass of Jupiter, independent of the SEP effect test.

Anderson, J D; Nordtvedt, K; Turyshev, S G; Anderson, John D; Gross, Mark; Nordtvedt, Kenneth L; Turyshev, Slava G

1995-01-01

422

Multiband signal reconstruction for random equivalent sampling.  

PubMed

The random equivalent sampling (RES) is a sampling approach that can be applied to capture high speed repetitive signals with a sampling rate that is much lower than the Nyquist rate. However, the uneven random distribution of the time interval between the excitation pulse and the signal degrades the signal reconstruction performance. For sparse multiband signal sampling, the compressed sensing (CS) based signal reconstruction algorithm can tease out the band supports with overwhelming probability and reduce the impact of uneven random distribution in RES. In this paper, the mathematical model of RES behavior is constructed in the frequency domain. Based on the constructed mathematical model, the band supports of signal can be determined. Experimental results demonstrate that, for a signal with unknown sparse multiband, the proposed CS-based signal reconstruction algorithm is feasible, and the CS reconstruction algorithm outperforms the traditional RES signal reconstruction method. PMID:25362458

Zhao, Y J; Liu, C J

2014-10-01

423

Equivalence of the Einstein and Jordan frames  

NASA Astrophysics Data System (ADS)

No experiment can measure an absolute scale: every dimensionful quantity has to be compared to some fixed unit scale in order to be measured, and thus only dimensionless quantities are really physical. The Einstein and Jordan frames are related by a conformal transformation of the metric, which amounts to rescaling all length scales. Since the absolute scale cannot be measured, both frames describe the same physics and are equivalent. In this article we make this explicit by rewriting the action in terms of dimensionless variables, which are invariant under a conformal transformation. For definitiveness, we concentrate on the action of Higgs inflation, but the results can easily be generalized. In addition, we show that the action for f (R ) gravity, which includes Starobinsky inflation, can be written in a frame-independent form.

Postma, Marieke; Volponi, Marco

2014-11-01

424

Equivalent formulations of “the equation of life”  

NASA Astrophysics Data System (ADS)

Motivated by progress in theoretical biology a recent proposal on a general and quantitative dynamical framework for nonequilibrium processes and dynamics of complex systems is briefly reviewed. It is nothing but the evolutionary process discovered by Charles Darwin and Alfred Wallace. Such general and structured dynamics may be tentatively named “the equation of life”. Three equivalent formulations are discussed, and it is also pointed out that such a quantitative dynamical framework leads naturally to the powerful Boltzmann-Gibbs distribution and the second law in physics. In this way, the equation of life provides a logically consistent foundation for thermodynamics. This view clarifies a particular outstanding problem and further suggests a unifying principle for physics and biology.

Ao, Ping

2014-07-01

425

Noise-equivalent sensitivity of photoacoustics  

PubMed Central

Abstract. The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.7×10?19??mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacoustics. The ultimate sensitivity of photoacoustics is fundamentally limited by thermal noise, which can present in the acoustic detection system as well as in the medium itself. Under the optimized conditions described herein and using commercially available detectors, photoacoustic microscopy can detect as few as 100s of oxygenated hemoglobin molecules. Realizable improvements to the detector may enable single molecule detection of select molecules. PMID:24026425

Winkler, Amy M.; Maslov, Konstantin; Wang, Lihong V.

2013-01-01

426

Gene Trapping Using Gal4 in Zebrafish  

PubMed Central

Large clutch size and external development of optically transparent embryos make zebrafish an exceptional vertebrate model system for in vivo insertional mutagenesis using fluorescent reporters to tag expression of mutated genes. Several laboratories have constructed and tested enhancer- and gene-trap vectors in zebrafish, using fluorescent proteins, Gal4- and lexA- based transcriptional activators as reporters 1-7. These vectors had two potential drawbacks: suboptimal stringency (e.g. lack of ability to differentiate between enhancer- and gene-trap events) and low mutagenicity (e.g. integrations into genes rarely produced null alleles). Gene Breaking Transposon (GBTs) were developed to address these drawbacks 8-10. We have modified one of the first GBT vectors, GBT-R15, for use with Gal4-VP16 as the primary gene trap reporter and added UAS:eGFP as the secondary reporter for direct detection of gene trap events. Application of Gal4-VP16 as the primary gene trap reporter provides two main advantages. First, it increases sensitivity for genes expressed at low expression levels. Second, it enables researchers to use gene trap lines as Gal4 drivers to direct expression of other transgenes in very specific tissues. This is especially pertinent for genes with non-essential or redundant functions, where gene trap integration may not result in overt phenotypes. The disadvantage of using Gal4-VP16 as the primary gene trap reporter is that genes coding for proteins with N-terminal signal sequences are not amenable to trapping, as the resulting Gal4-VP16 fusion proteins are unlikely to be able to enter the nucleus and activate transcription. Importantly, the use of Gal4-VP16 does not pre-select for nuclear proteins: we recovered gene trap mutations in genes encoding proteins which function in the nucleus, the cytoplasm and the plasma membrane. PMID:24121167

Balciuniene, Jorune; Balciunas, Darius

2013-01-01

427

Loading of multiple micro-optical traps  

NASA Astrophysics Data System (ADS)

Pioneering work has been done in the use of far off-resonant laser fields to create potentials to trap and manipulate neutral atoms in the last few decades. More recently multiple traps with variable separation between them have become useful for various experiments ranging from quantum information research to cold collisions and atom interferometry. We present a new method of generating a linear array of far off resonant-traps (FORTs) making use of the intensity pattern associated with the spherical aberration of a focused CO2 laser beam [ 1 ]. The spherical aberration is introduced by the lenses in the path of the laser beam. Atoms are trapped at the local maxima of the intensity pattern. We show that the separation of these micro-traps can be varied over a range of about one millimeter. The variation of the separation of these micro-traps is achieved by changing the amount of spherical aberration which is made possible by changing the CO2 laser beam size on the lenses. We could load about 2 x10^5 - 1 x10^6 atoms in these micro-traps at 70 ?K. Since the spacial extent of the magneto optical trap (MOT) (from where the FORT is loaded) is limited, 2 - 3 micro-traps are realized at a time. However by changing the relative position of the MOT with respect to FORT up to 10 micro-traps are observed.[ 1 ] P Ahmadi, V Ramareddy and G S Summy, New. J. Phys. 7, 4 (2005).

Ramareddy, Vijayashankar

2005-05-01

428

Physica A 357 (2005) 427435 Thermodynamic equivalence of certain ideal  

E-print Network

that the equivalence for systems with a constant DOS is a special case of a more general equivalence between wavelength, allowing for the possibility of different T, V, and N. K.R. Patton et al. / Physica A 357 (2005

Geller, Michael R.

429

14 CFR 21.461 - Equivalent safety provisions.  

Code of Federal Regulations, 2010 CFR

...PRODUCTS AND PARTS Designated Alteration Station Authorization Procedures § 21.461 Equivalent safety provisions. The DAS shall obtain the Administrator's concurrence on the application of all equivalent safety provisions applied under §...

2010-01-01

430

30 CFR 71.206 - Approved sampling devices; equivalent concentrations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Approved sampling devices; equivalent concentrations. 71...SURFACE WORK AREAS OF UNDERGROUND COAL MINES Sampling Procedures § 71.206 Approved sampling devices; equivalent concentrations....

2010-07-01

431

30 CFR 90.206 - Approved sampling devices; equivalent concentrations.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Approved sampling devices; equivalent concentrations. 90...EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.206 Approved sampling devices; equivalent concentrations....

2010-07-01

432

Elementary equivalence of Chevalley groups over local rings  

SciTech Connect

It is proved that (elementary) Chevalley groups over local rings with invertible 2 are elementarily equivalent if and only if their types and weight lattices coincide and the initial rings are elementarily equivalent. Bibliography: 25 titles.

Bunina, Elena I [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

2010-05-11

433

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Hunting, fishing, and trapping. 423.32...WATERBODIES Rules of Conduct § 423.32 Hunting, fishing, and trapping. (a...additional restrictions pertaining to hunting, fishing, and trapping established...

2011-10-01

434

36 CFR 331.3 - Hunting and trapping.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Hunting and trapping. 331.3 Section 331...AREA, KENTUCKY AND INDIANA § 331.3 Hunting and trapping. Unless authorized in writing by the District Engineer: (a) The hunting, trapping, catching,...

2012-07-01

435

36 CFR 331.3 - Hunting and trapping.  

...2014-07-01 2014-07-01 false Hunting and trapping. 331.3 Section 331...AREA, KENTUCKY AND INDIANA § 331.3 Hunting and trapping. Unless authorized in writing by the District Engineer: (a) The hunting, trapping, catching,...

2014-07-01

436

36 CFR 331.3 - Hunting and trapping.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2012-07-01 true Hunting and trapping. 331.3 Section 331...AREA, KENTUCKY AND INDIANA § 331.3 Hunting and trapping. Unless authorized in writing by the District Engineer: (a) The hunting, trapping, catching,...

2013-07-01

437

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Hunting, fishing, and trapping. 423.32...WATERBODIES Rules of Conduct § 423.32 Hunting, fishing, and trapping. (a...additional restrictions pertaining to hunting, fishing, and trapping established...

2010-10-01

438

43 CFR 423.32 - Hunting, fishing, and trapping.  

...2014-10-01 2014-10-01 false Hunting, fishing, and trapping. 423.32...WATERBODIES Rules of Conduct § 423.32 Hunting, fishing, and trapping. (a...additional restrictions pertaining to hunting, fishing, and trapping established...

2014-10-01

439

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2011-10-01 true Hunting, fishing, and trapping. 423.32...WATERBODIES Rules of Conduct § 423.32 Hunting, fishing, and trapping. (a...additional restrictions pertaining to hunting, fishing, and trapping established...

2012-10-01

440

36 CFR 331.3 - Hunting and trapping.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Hunting and trapping. 331.3 Section 331...AREA, KENTUCKY AND INDIANA § 331.3 Hunting and trapping. Unless authorized in writing by the District Engineer: (a) The hunting, trapping, catching,...

2011-07-01

441

36 CFR 331.3 - Hunting and trapping.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hunting and trapping. 331.3 Section 331...AREA, KENTUCKY AND INDIANA § 331.3 Hunting and trapping. Unless authorized in writing by the District Engineer: (a) The hunting, trapping, catching,...

2010-07-01

442

43 CFR 423.32 - Hunting, fishing, and trapping.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Hunting, fishing, and trapping. 423.32...WATERBODIES Rules of Conduct § 423.32 Hunting, fishing, and trapping. (a...additional restrictions pertaining to hunting, fishing, and trapping established...

2013-10-01

443

LETTER TO THE EDITOR: Trapped surfaces and symmetries  

NASA Astrophysics Data System (ADS)

We prove that strictly stationary spacetimes cannot contain closed trapped or marginally trapped surfaces. The result is purely geometric and holds in arbitrary dimension. Other results concerning the interplay between (generalized) symmetries and trapped submanifolds are also presented.

Mars, Marc; Senovilla, JosA~© M. M.

2003-12-01

444

Effects of a meaningful, a discriminative, and a meaningless stimulus on equivalence class formation.  

PubMed

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A-E stimuli were abstract shapes and the C stimuli became S(D)s prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated "partial" class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes. PMID:22389524

Fields, Lanny; Arntzen, Erik; Nartey, Richard K; Eilifsen, Christoffer

2012-03-01

445

Effects of a Meaningful, a Discriminative, and a Meaningless Stimulus on Equivalence Class Formation  

PubMed Central

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A–E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A–E stimuli were abstract shapes and the C stimuli became SDs prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated “partial” class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes. PMID:22389524

Fields, Lanny; Arntzen, Erik; Nartey, Richard K; Eilifsen, Christoffer

2012-01-01

446

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. PMID:8851537

Lane, S D; Critchfield, T S

1996-01-01

447

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

448

Equivalent inclusion method for steady state heat conduction in composites  

Microsoft Academic Search

The equivalent inclusion method is proposed to solve the steady state heat conduction problems in composites. This method is analogous to Eshelby's equivalent inclusion method in elasticity. Thus, the solution procedure by this method is very simple, involving only algebraic operations. The equivalent inclusion method developed here is also applicable to the case of high concentrations of ellipsoidal inhomogeneities. As

H Hiroshi; M. Taya

1986-01-01

449

1 equivalence structures Douglas Cenzer, Department of Mathematics  

E-print Network

0 1 and 0 1 equivalence structures Douglas Cenzer, Department of Mathematics University of Florida computability theoretic properties of 0 1 and 0 1 equiv- alence structures and how they differ from computable equivalence structures or equivalence structures that belong to the Ershov differ- ence hierarchy. Our

Cenzer, Douglas

450

Understanding Phase Shifting Equivalent Keys and Exhaustive Search  

E-print Network

Understanding Phase Shifting Equivalent Keys and Exhaustive Search C^ome Berbain1, Aline Gouget2 the concept of phase shift- ing equivalent keys in stream ciphers, and exploit this concept in order to mount attacks on some specific ciphers. The idea behind phase shifting equivalent keys is that, for many ciphers

451

Understanding Phase Shifting Equivalent Keys and Exhaustive Search  

E-print Network

Understanding Phase Shifting Equivalent Keys and Exhaustive Search Câ??ome Berbain 1 , Aline Gouget 2 the concept of phase shift­ ing equivalent keys in stream ciphers, and exploit this concept in order to mount attacks on some specific ciphers. The idea behind phase shifting equivalent keys is that, for many ciphers

452

Position-Numeral Equivalences and Delayed Position Recognition Span.  

ERIC Educational Resources Information Center

The role of equivalence class formation in delayed position recognition span performance was examined with three mentally retarded adults. Matching-to-sample training established equivalence classes. In subsequent span tests, subject-produced numeral names led to dramatic increases in span scores. The equivalences provided precursors of verbal…

Mackay, Harry A.; Ratti, Carla A.

1990-01-01

453

Local Equivalence of Rank-Two Quantum Mixed States  

E-print Network

We investigate the equivalence of quantum mixed states under local unitary transformations. For a class of rank-two mixed states, a sufficient and necessary condition of local equivalence is obtained by giving a complete set of invariants under local unitary transformations, such that two states in this class are locally equivalent if and only if all these invariants have equal values for them.

Sergio Albeverio; Shao-Ming Fei; Debashish Goswami

2007-11-08

454

On the Origins of the Task Mixing Cost in the Cuing Task-Switching Paradigm  

Microsoft Academic Search

Poorer performance in conditions involving task repetition within blocks of mixed tasks relative to task repetition within blocks of single task is called mixing cost (MC). In 2 experiments exploring 2 hypotheses regarding the origins of MC, participants either switched between cued shape and color tasks, or they performed them as single tasks. Experiment 1 supported the hypothesis that mixed-tasks

Orit Rubin; Nachshon Meiran

2005-01-01

455

Resolving Task Rule Incongruence during Task Switching by Competitor Rule Suppression  

ERIC Educational Resources Information Center

Task switching requires maintaining readiness to execute any task of a given set of tasks. However, when tasks switch, the readiness to execute the now-irrelevant task generates interference, as seen in the task rule incongruence effect. Overcoming such interference requires fine-tuned inhibition that impairs task readiness only minimally. In an…

Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard

2010-01-01

456

Task-switching and long-term priming: Role of episodic stimulus-task bindings in task-shift costsq  

Microsoft Academic Search

When subjects switch between two tasks, performance is slower after a task switch than af- ter a task repetition. We report five experiments showing that a large part of these ''task-shift- costs'' cannot be attributed to a control operation, needed to configure the cognitive system for the upcoming task (e.g., Rogers & Monsell, 1995). In all experiments subjects switched be-

Florian Waszak; Bernhard Hommel; Alan Allportc

2003-01-01

457

A method for trapping breeding adult American Oystercatchers  

USGS Publications Warehouse

We present an efficient and effective method for trapping adult, breeding American Oystercatchers (Haematopus palliatus) that minimizes disturbance to nesting birds and the risk of trapping injuries. We used a remote controlled mechanical decoy to lure territorial adults to a leg-hold noose-mat trap. We trapped 25 birds over two seasons and were successful on 54% of our trapping attempts in 2003. We only trapped birds before the breeding season or between nesting attempts to reduce nest-site disturbance.

McGowan, C.P.; Simons, T.R.

2005-01-01

458

Responses of wild muskrats ( Ondatra zibethicus L.) to scented traps  

Microsoft Academic Search

Free-ranging muskrats were trapped in scented and blank traps in New York State at local ponds during all seasons and at a wildlife refuge in spring and early summer. In a total of 4839 trap-nights, 65 muskrats were caught. Trapping success was 1.34%. The overall responses to differently scented traps differed significantly. Adults preferentially entered blank and food-baited traps, whereas

JAN VAN DEN BERK; D. Müller-Schwarze

1984-01-01

459

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

460

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

461

Electrostatic trapping of ultracold polar molecules  

NASA Astrophysics Data System (ADS)

This thesis describes the progress made in the production, spectroscopic characterization, and confinement of ultracold, polar NaCs molecules. A two-species MOT for the simultaneous cooling and trapping of sodium and cesium atoms is utilized for the creation of ultracold NaCs molecules via photoassociation. The molecules are detected via resonance-enhanced multi-photon ionization and subsequent ion detection with a channel electron multiplier. Spectra are obtained by scanning the frequencies of the photoassociating laser and the photoionizing laser. The resulting discovery that deeply bound, strongly polar molecules are created via one-step photoassociation has lead to efforts to confine the molecules via electric field trapping. The design of an electric field trap for polar molecules that can be superposed onto a magneto-optical trap is presented. This 'Thin WIre electro-Static Trap' (TWIST) has been built and successfully implemented. First experiments beyond the demonstration of successful trapping of NaCs molecules have been conducted, showing the effects of dissociative photoionization and inelastic collisions of electrically trapped NaCs molecules with cesium atoms confined by a MOT. An outline of a possible pathway to a quantum degenerate dipolar gas, exploiting the properties of the TWIST, is given at the end of this thesis.

Kleinert, Jan

462

Neutrino trapping in braneworld extremely compact stars  

NASA Astrophysics Data System (ADS)

Extremely Compact Stars (ECS) contain trapped null geodesics. When such objects enter the evolution period admitting geodetical motion of neutrinos, certain part of neutrinos produced in their interior will be trapped influencing their neutrino luminosity and thermal evolution. We study neutrino trapping in the braneworld ECS, assuming uniform distribution of neutrino emissivity and massless neutrinos. We give the efficiency of the neutrino trapping effects in the framework of the simple model of the internal spacetime with uniform distribution of energy density, and external spacetime described by the Reissner-Nordström geometry characterized by the braneworld "tidal" parameter b. For b < 0 the external spacetime is of the black-hole type, while for b > 0 the external spacetime can be of both black-hole and naked-singularity type. Then the ECS surface radius R can be located also above the unstable (outer) photon circular orbit. Such basically new types of the spacetimes strongly alter the trapping phenomena as compared to the standard case of b = 0. It is shown that the neutrino trapping effects are slightly lowered by the presence of physically more plausible case of b < 0, as compared to the standard internal Schwarzschild spacetime, while they can be magnified by positive tidal charges if b < 1 and lowered for b > 1. However, potential astrophysical relevance of the trapping phenomena is strongly enhanced for negative tidal charges enabling a significant enlargement of the ECS surface radius to values coherent with recent observations.

Stuchlík, Zden?k; Hladík, Jan; Urbanec, Martin

2011-11-01

463

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

464

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

PubMed

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. PMID:11537535

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

1992-07-01

465

Nonlinear Spectroscopy of Trapped Ions  

E-print Network

Nonlinear spectroscopy employs a series of laser pulses to interrogate dynamics in large interacting many-body systems, and has become a highly successful method for experiments in chemical physics. Current quantum optical experiments approach system sizes and levels of complexity which require the development of efficient techniques to assess spectral and dynamical features with scalable experimental overhead. However, established methods from optical spectroscopy of macroscopic ensembles cannot be applied straightforwardly to few-atom systems. Based on the ideas proposed in [M. Gessner et al. New J. Phys. 16 092001 (2014)], we develop a diagrammatic approach to construct nonlinear measurement protocols for controlled quantum systems and discuss experimental implementations with trapped ion technology in detail. These methods in combination with distinct features of ultra-cold matter systems allow us to monitor and analyze excitation dynamics in both the electronic and vibrational degrees of freedom. They are independent of system size, and can therefore reliably probe systems where, e.g., quantum state tomography becomes prohibitively expensive. We propose signals that can probe steady state currents, detect the influence of anharmonicities on phonon transport, and identify signatures of chaotic dynamics near a quantum phase transition in an Ising-type spin chain.

Frank Schlawin; Manuel Gessner; Shaul Mukamel; Andreas Buchleitner

2014-10-07

466

Optical Trapping at Gigapascal Pressures  

NASA Astrophysics Data System (ADS)

Diamond anvil cells allow the behavior of materials to be studied at pressures up to hundreds of gigapascals in a small and convenient instrument. However, physical access to the sample is impossible once it is pressurized. We show that optical tweezers can be used to hold and manipulate particles in such a cell, confining micron-sized transparent beads in the focus of a laser beam. Here, we use a modified optical tweezers geometry, allowing us to trap through an objective lens with a higher working distance, overcoming the constraints imposed by the limited angular acceptance of the anvil cell. We demonstrate the effectiveness of the technique by measuring water’s viscosity at pressures of up to 1.3 GPa. In contrast to previous viscosity measurements in anvil cells, our technique measures absolute viscosity and does not require scaling to the accepted value at atmospheric pressure. This method could also measure the frequency dependence of viscosity as well as being sensitive to anisotropy in the medium’s viscosity.

Bowman, Richard W.; Gibson, Graham M.; Padgett, Miles J.; Saglimbeni, Filippo; Di Leonardo, Roberto

2013-03-01

467

Atom trap loss, elastic collisions, and technology  

NASA Astrophysics Data System (ADS)

The study of collisions and scattering has been one of the most productive approaches for modern physics, illuminating the fundamental structure of crystals, surfaces, atoms, and sub-atomic particles. In the field of cold atoms, this is no less true: studies of cold atom collisions were essential to the production of quantum degenerate matter, the formation of cold molecules, and so on. Over the past few years it has been my delight to investigate elastic collisions between cold atoms trapped in either a magneto-optical trap (MOT) or a magnetic trap with hot, background gas in the vacuum environment through the measurement of the loss of atoms from the trap. Motivated by the goal of creating cold atom-based technology, we are deciphering what the trapped atoms are communicating about their environment through the observed loss rate. These measurements have the advantages of being straightforward to implement and they provide information about the underlying, fundamental inter-atomic processes. In this talk I will present some of our recent work, including the observation of the trap depth dependence on loss rate for argon-rubidium collisions. The data follow the computed loss rate curve based on the long-range Van der Waals interaction between the two species. The implications of these findings are exciting: trap depths can be determined from the trap loss measurement under controlled background density conditions; observation of trap loss rate in comparison to models for elastic, inelastic, and chemical processes can lead to improved understanding and characterization of these fundamental interactions; finally the marriage of cold atoms with collision modeling offers the promise of creating a novel pressure sensor and pressure standard for the high and ultra-high vacuum regime.

Booth, James

2012-10-01

468

Individual Differences in Vigilance Tasks  

E-print Network

, Yardley, & Gresty, 2003; Liao & Drury, 2000); administering caffeine (Tharion et al., 1997); and even of these approaches are relevant to DHS vigilance tasks. Specific to DHS-relevant training, Uenking (2000) used

McShea, Daniel W.

469

Interacting Tasks Part I. Preliminaries  

E-print Network

-Worker Chapter 17. Interacting Tasks Chapter 18. MPI Part IV. GPU Acceleration Part V. Big Data #12;17­2 BIG main program. public void main (String[] args) { // Parse command line arguments. if (args.length != 8

Kaminsky, Alan

470

Response Devices and Cognitive Tasks.  

National Technical Information Service (NTIS)

The aims of the research are to study the effects of response mode, response complexity, instructions and practice on basic cognitive tasks, and to use the information obtained to develop more elaborate models of cognitive functioning which take these fac...

D. K. Detterman

1991-01-01

471

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

472

Security tasks are highly interdependent.  

E-print Network

that monitor Internet - Security consultant - Community of practice - Content providers End-Users -ExperienceMotivation Security tasks are highly interdependent. To improve security tools, we need to understand how security practitioners collaborate in their organizations. Security practitioners in context

473

Equivalent Circuit Analysis of Super-Planckian Emission into Far Field  

E-print Network

Using our recently developed equivalent circuit model of radiative heat transfer we analyze the far-field thermal emission from bodies of constrained dimensions. We prove that the power radiated by a hypothetical metamaterial emitter which is conjugate matched with all the harmonics of the emitted field at a given wavelength can be infinitely higher than the power emitted by an ideal black body of the same radius. However, for optically large bodies, fulfilling the conjugate match conditions for higher-order harmonics is not a trivial task, which effectively limits the far-field radiated power by the well-known Planck law.

Maslovski, Stanislav I

2014-01-01

474

Comparison of octenol- and BG Lure-baited biogents sentinel traps and an encephalitis virus surveillance trap in Portland, OR.  

PubMed

Two types of mosquito trap were tested near Smith Lake in Portland, Multnomah County, OR: 2 Biogents Sentinel (BGS) traps baited with carbon dioxide (CO2) and an octenol sachet or a BG Lure, and an encephalitis virus surveillance (EVS) trap with CO2 but without an odor sachet. After 6 trap-nights, the 2 BGS traps caught significantly more mosquitoes than the EVS trap. More Culex tarsalis and an overall greater number of species were caught in the BGS traps. A BGS trap and an EVS trap, both baited with CO2 alone, were compared to investigate whether the difference was due to the attractants or the difference in trap type. The BGS trap caught more mosquitoes but the difference was not significant. The BGS trap, when baited with CO2 and other lures, can be an effective mosquito sampling tool, but further research is needed to understand the importance of the attractants. PMID:18939691

Irish, Seth R; Chandre, Fabrice; N'Guessan, Raphael

2008-09-01

475

Maximize Student Time On Task  

NSDL National Science Digital Library

Student time on task is the most influential factor in student achievement. To maximize time on task, teachers need to make decisions about the systems they install in their classroom well before any students enter the room. Beginning the school year by explicitly teaching process skills and having classroom operating systems that reinforce process skills are two strategies that lay the foundation for logical thinking throughout the year, which are discussed in this article.

Peters, Erin

2004-09-01

476

Microparticle trapping in an ultrasonic Bessel beam  

PubMed Central

This paper describes an acoustic trap consisting of a multi-foci Fresnel lens on 127??m thick lead zirconate titanate sheet. The multi-foci Fresnel lens was designed to have similar working mechanism to an Axicon lens and generates an acoustic Bessel beam, and has negative axial radiation force capable of trapping one or more microparticle(s). The fabricated acoustic tweezers trapped lipid particles ranging in diameter from 50 to 200??m and microspheres ranging in diameter from 70 to 90??m at a distance of 2 to 5?mm from the tweezers without any contact between the transducer and microparticles. PMID:22247566

Choe, Youngki; Kim, Jonathan W.; Shung, K. Kirk; Kim, Eun Sok

2011-01-01

477

The Non-Trapping Degree of Scattering  

E-print Network

We consider classical potential scattering. If no orbit is trapped at energy E, the Hamiltonian dynamics defines an integer-valued topological degree. This can be calculated explicitly and be used for symbolic dynamics of multi-obstacle scattering. If the potential is bounded, then in the non-trapping case the boundary of Hill's Region is empty or homeomorphic to a sphere. We consider classical potential scattering. If at energy E no orbit is trapped, the Hamiltonian dynamics defines an integer-valued topological degree deg(E) scattering. This comprises a large number of earlier results, obtained by different authors on multi-obstacle scattering.

Andreas Knauf; Markus Krapf

2007-06-21

478

Robust Digital Holography For Ultracold Atom Trapping  

PubMed Central

We have formulated and experimentally demonstrated an improved algorithm for design of arbitrary two-dimensional holographic traps for ultracold atoms. Our method builds on the best previously available algorithm, MRAF, and improves on it in two ways. First, it allows for creation of holographic atom traps with a well defined background potential. Second, we experimentally show that for creating trapping potentials free of fringing artifacts it is important to go beyond the Fourier approximation in modelling light propagation. To this end, we incorporate full Helmholtz propagation into our calculations. PMID:23056913

Gaunt, Alexander L.; Hadzibabic, Zoran

2012-01-01

479

Holographic optical trapping of aerosol droplets.  

PubMed

We demonstrate the use of holographic optical tweezers for trapping particles in air, specifically aerosol droplets. We show the trapping and manipulation of arrays of liquid aerosols as well as the controlled coagulation of two or more droplets. We discuss the ability of spatial light modulators to manipulate airborne droplets in real time as well as highlight the difficulties associated with loading and trapping particles in such an environment. We conclude with a discussion of some of the applications of such a technique. PMID:19516567

Burnham, D R; McGloin, D

2006-05-01

480

Holographic optical trapping of aerosol droplets.  

PubMed

We demonstrate the use of holographic optical tweezers for trapping particles in air, specifically aerosol droplets. We show the trapping and manipulation of arrays of liquid aerosols as well as the controlled coagulation of two or more droplets. We discuss the ability of spatial light modulators to manipulate airborne droplets in real time as well as highlight the difficulties associated with loading and trapping particles in such an environment. We conclude with a discussion of some of the applications of such a technique. PMID:19516568

Burnham, D R; McGloin, D

2006-05-01

481

Local existence of dynamical and trapping horizons  

E-print Network

Given a spacelike foliation of a spacetime and a marginally outer trapped surface S on some initial leaf, we prove that under a suitable stability condition S is contained in a ``horizon'', i.e. a smooth 3-surface foliated by marginally outer trapped slices which lie in the leaves of the given foliation. We also show that under rather weak energy conditions this horizon must be either achronal or spacelike everywhere. Furthermore, we discuss the relation between ``bounding'' and ``stability'' properties of marginally outer trapped surfaces.

Lars Andersson; Marc Mars; Walter Simon

2005-06-02

482

Symmetry dependence of holograms for optical trapping.  

PubMed

No iterative algorithm is necessary to calculate holograms for most holographic optical trapping patterns. Instead, holograms may be produced by a simple extension of the prisms-and-lenses method. This formulaic approach yields the same diffraction efficiency as iterative algorithms for any asymmetric or symmetric but nonperiodic pattern of points while requiring less calculation time. A slight spatial disordering of periodic patterns significantly reduces intensity variations between the different traps without extra calculation costs. Eliminating laborious hologram calculations should greatly facilitate interactive holographic trapping. PMID:16127918

Curtis, Jennifer E; Schmitz, Christian H J; Spatz, Joachim P

2005-08-15

483

How to Set a Pitfall Trap  

NSDL National Science Digital Library

In this Biodiversity Counts activity, students learn how to create and set up a pitfall trap to catch soil dwellers. The online activity page includes easy-to-follow directions for building a trap with recycled plastic containers, stones, wood/cardboard, and a bait of the students' choosing. Students let the trap sit either for a few hours or overnight to see what they have caught. To expand their investigation, students are challenged to experiment with different baits to see if they can attract different arthropods.

484

Voluntary Task Switching: Chasing the Elusive Homunculus  

ERIC Educational Resources Information Center

In the voluntary task switching procedure, subjects choose the task to perform on a series of bivalent stimuli, requiring top-down control of task switching. Experiments 1-3 contrasted voluntary task switching and explicit task cuing. Choice behavior showed small, inconsistent effects of external stimulus characteristics, supporting the assumption…

Arrington, Catherine M.; Logan, Gordon D.

2005-01-01

485

Decentralized Allocation of Tasks with Delayed Commencement  

Microsoft Academic Search

In this paper we propose an approach for flexible and decentralized task allocation based on a negotia- tion protocol and applicable in case of delayed commencement of tasks. Delayed task commencement arises when an agent has to make some eort in order to start the task, e.g. a robot first has to move towards the starting position of its task

Nelis Boucke; Danny Weyns; Tom Holvoet; Koenraad Mertens

2004-01-01

486

Dynamic equivalence between atomic and colloidal liquids  

E-print Network

We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient D_S 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 D_S, will indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio D_L/ D_S 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[Phys. Rev. Lett. 70, 1557 (1993)]. We corroborate these predictions by comparing molecular and Brownian dynamics simulations on (soft- and hard-sphere) model systems, representative of what we may refer to as the "hard-sphere" dynamic universality class.

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

2011-06-13

487

The Equivalence of Time and Gravitational Field  

NASA Astrophysics Data System (ADS)

The relationship between energy, time and space is still not solved in an appropriate manner. According to Newton's concept of time and space, both have to be taken as absolute. If we follow Leibniz and his arguments, space and time are relative. Since Einstein's theory of relativity we know at least that energy, time and space are deeply related. Albert Einstein originally predicted that time is nothing absolute but something relative, time changes and can change. Especially, time and gravitational field are related somehow even in detail if we still don’t know how. According to the gravitational time dilation, the lower the gravitational potential, the more slowly time passes and vice versa. Somehow, it appears to be that the behaviour of time is directly linked to the behaviour of the gravitational field. The aim of this publication is to work out the interior logic between time and gravitational field and to make the proof that time is equivalent to the gravitational field and vice versa.

Baruk?i?a, Ilija

488

Challenging a culture of racial equivalence.  

PubMed

We live at a time when our understandings and conceptualizations of 'racism' are often highly imprecise, broad, and used to describe a wide range of racialized phenomena. In this article, I raise some important questions about how the term racism is used and understood in contemporary British society by drawing on some recent cases of alleged racism in football and politics, many of which have been played out via new media technologies. A broader understanding of racism, through the use of the term 'racialization', has been helpful in articulating a more nuanced and complex understanding of racial incidents, especially of people's (often ambivalent) beliefs and behaviours. However, the growing emphasis upon 'racialization' has led to a conceptualization of racism which increasingly involves multiple perpetrators, victims, and practices without enough consideration of how and why particular interactions and practices constitute racism as such. The trend toward a growing culture of racial equivalence is worrying, as it denudes the idea of racism of its historical basis, severity and power. These frequent and commonplace assertions of racism in the public sphere paradoxically end up trivializing and homogenizing quite different forms of racialized interactions. I conclude that we need to retain the term 'racism', but we need to differentiate more clearly between 'racism' (as an historical and structured system of domination) from the broader notion of 'racialization'. PMID:24697716

Song, Miri

2014-03-01

489

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

490

Guidelines for the derivation of Biomonitoring Equivalents: Report from the Biomonitoring Equivalents Expert Workshop  

Microsoft Academic Search

Biomonitoring Equivalents (BEs) are defined as the concentration of a chemical (or metabolite) in a biological medium (blood, urine, human milk, etc.) consistent with defined exposure guidance values or toxicity criteria including reference doses and reference concentrations (RfD and RfCs), minimal risk levels (MRLs), or tolerable daily intakes (TDIs) [Hays, S.M., Becker, R.A., Leung, H.W., Aylward, L.L., Pyatt, D.W., 2007.

Sean M. Hays; Lesa L. Aylward; Judy S. LaKind; Michael J. Bartels; Hugh A. Barton; Peter J. Boogaard; Conrad Brunk; Stephen DiZio; Michael Dourson; Daniel A. Goldstein; John Lipscomb; Michael E. Kilpatrick; Daniel Krewski; Kannan Krishnan; Monica Nordberg; Miles Okino; Yu-Mei Tan; Claude Viau; Janice W. Yager

2008-01-01

491

Spatial density oscillations in trapped dipolar condensates  

SciTech Connect

We investigated the ground-state wave function and the free expansion of a trapped dipolar condensate. We find that dipolar interaction may induce both biconcave and dumbbell density profiles in the pancake- and cigar-shaped traps, respectively. In the parameter plane of the interaction strengths, the oscillating density profile in a harmonically trapped dipolar condensate occurs only when the interaction parameters fall into certain isolated areas. The relation between the positions of these areas and the trap geometry is explored. When a box potential is used to confine the condensate, spatial density oscillation becomes a generic feature. By studying the free expansion of the condensate with an oscillating density profile, we show that the spatial density oscillation is detectable from the time-of-flight image.

Lu, H.-Y.; Zhang, J.-N.; Qiu, R.-Z.; Yi, S. [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Lu, H.; Pu, H. [Department of Physics and Astronomy, and Rice Quantum Institute, Rice University, Houston, Texas 77251 (United States)

2010-08-15

492

Acoustofluidics 20: applications in acoustic trapping.  

PubMed

This part of the Acoustofluidics tutorial series reviews applications in acoustic trapping of micron-sized particles and cells in microfluidic systems. Acoustic trapping enables non-invasive and non-contact immobilisation of cells and particles in microfluidic systems. Acoustic trapping has been used for reducing the time needed to create 3D cell clusters, enhance particle-based bioassays and facilitated interaction studies of both cells and particles. An area that is increasingly interesting is the use of acoustic trapping for enriching low concentration samples and the washing or fractioning of cell populations prior to sensitive detection methods (MALDI-MS, PCR etc.) The main focus of the review is systems where particles can be retained against a flow while applications in which particles are positioned in a stationary fluid will be addressed in part 21 of the Acoustofluidics tutorial series (M. Wiklund, S. Radel and J. J. Hawkes, Lab Chip, 2012, 12, ). PMID:23047553

Evander, Mikael; Nilsson, Johan

2012-11-21

493

Exploration and Trapping of Mortal Random Walkers  

E-print Network

Exploration and trapping properties of random walkers that may evanesce at any time as they walk have seen very little treatment in the literature, and yet a finite lifetime is a frequent occurrence, and its effects on a number of random walk properties may be profound. For instance, whereas the average number of distinct sites visited by an immortal walker grows with time without bound, that of a mortal walker may, depending on dimensionality and rate of evanescence, remain finite or keep growing with the passage of time. This number can in turn be used to calculate other classic quantities such as the survival probability of a target surrounded by diffusing traps. If the traps are immortal, the survival probability will vanish with increasing time. However, if the traps are evanescent, the target may be spared a certain death. We analytically calculate a number of basic and broadly used quantities for evanescent random walkers.

S. B. Yuste; E. Abad; Katja Lindenberg

2013-04-28

494

Scaling the ion trap quantum processor.  

PubMed

Trapped atomic ions are standards for quantum information processing, serving as quantum memories, hosts of quantum gates in quantum computers and simulators, and nodes of quantum communication networks. Quantum bits based on trapped ions enjoy a rare combination of attributes: They have exquisite coherence properties, they can be prepared and measured with nearly 100% efficiency, and they are readily entangled with each other through the Coulomb interaction or remote photonic interconnects. The outstanding challenge is the scaling of trapped ions to hundreds or thousands of qubits and beyond, at which scale quantum processors can outperform their classical counterparts in certain applications. We review the latest progress and prospects in that effort, with the promise of advanced architectures and new technologies, such as microfabricated ion traps and integrated photonics. PMID:23471398

Monroe, C; Kim, J

2013-03-01

495

Metallic nano-particles for trapping light  

PubMed Central

We study metallic nano-particles for light trapping by investigating the optical absorption efficiency of the hydrogenated amorphous silicon thin film with and without metallic nano-particles on its top. The size and shape of these nano-particles are investigated as to their roles of light trapping: scattering light to the absorption medium and converting light to surface plasmons. The optical absorption enhancement in the red light region (e.g., 650nm) due to the light trapping of the metallic nano-particles is observed when a layer of metallic nano-particle array has certain structures. The investigation of the light with incident angles shows the importance of the coupling efficiency of light to surface plasmons in the metallic nano-particle light trapping. PACS 73.20.Mf, 42.25.s, 88.40.hj PMID:23391493

2013-01-01

496

Focused plasmonic trapping of metallic particles  

PubMed Central

Scattering forces in focused light beams push away metallic particles. Thus, trapping metallic particles with conventional optical tweezers, especially those of Mie particle size, is difficult. Here we investigate a mechanism by which metallic particles are attracted and trapped by plasmonic tweezers when surface plasmons are excited and focused by a radially polarized beam in a high-numerical-aperture microscopic configuration. This contrasts the repulsion exerted in optical tweezers with the same configuration. We believe that different types of forces exerted on particles are responsible for this contrary trapping behaviour. Further, trapping with plasmonic tweezers is found not to be due to a gradient force balancing an opposing scattering force but results from the sum of both gradient and scattering forces acting in the same direction established by the strong coupling between the metallic particle and the highly focused plasmonic field. Theoretical analysis and simulations yield good agreement with experimental results. PMID:24305554

Min, Changjun; Shen, Zhe; Shen, Junfeng; Zhang, Yuquan; Fang, Hui; Yuan, Guanghui; Du, Luping; Zhu, Siwei; Lei, Ting; Yuan, Xiaocong

2013-01-01

497

Effects of Starfish on Geomagnetically Trapped Protons.  

National Technical Information Service (NTIS)

Measurements of geomagnetically-trapped, 55 MeV protons made before and after the detonation of the STARFISH nuclear device revealed that at low altitudes the flux increased considerably after the STARFISH burst. Theoretical analyses presented in this rep...

J. B. Cladis, G. T. Davidson, W. E. Francis, R. K. Jaggi, G. H. Nakano

1969-01-01

498

Rainbow Trapping in Hyperbolic Metamaterial Waveguide  

PubMed Central

The recent reported trapped “rainbow” storage of light using metamaterials and plasmonic graded surface gratings has generated considerable interest for on-chip slow light. The potential for controlling the velocity of broadband light in guided photonic structures opens up tremendous opportunities to manipulate light for optical modulation, switching, communication and light-matter interactions. However, previously reported designs for rainbow trapping are generally constrained by inherent difficulties resulting in the limited experimental realization of this intriguing effect. Here we propose a hyperbolic metamaterial structure to realize a highly efficient rainbow trapping effect, which, importantly, is not limited by those severe theoretical constraints required in previously reported insulator-negative-index-insulator, insulator-metal-insulator and metal-insulator-metal waveguide tapers, and therefore representing a significant promise to realize the rainbow trapping structure practically. PMID:23409240

Hu, Haifeng; Ji, Dengxin; Zeng, Xie; Liu, Kai; Gan, Qiaoqiang

2013-01-01

499

Are Your Steam Traps Leaking Money?  

ERIC Educational Resources Information Center

Contends that small defects in steam heating systems often go unnoticed, while efficiency drops. Presents guidelines for detecting steam loss through trap orifices and determining how much they are costing. (Author/MLF)

American School and University, 1974

1974-01-01

500

Transparent ion trap with integrated photodetector  

E-print Network

Fluorescence collection sets the efficiency of state detection and the rate of entanglement generation between remote trapped ion qubits. Despite efforts to improve light collection using various optical elements, solid ...

Wang, Shannon X.