Science.gov

Sample records for achieve high luminosity

  1. High-luminosity considerations

    SciTech Connect

    Platner, E.D.

    1982-01-01

    There appears to be some controversy over how high a luminosity one can use before a variety of detector limitations impose a practical limit. Factors leading to flux limitations for a variety of detector types are discussed, and practical considerations to extending those limits are reviewed. Also, a method of reducing the effects of pileup inherent in calorimeter use at L = 10/sup 33//cm/sup 2//sec is given.

  2. High luminosity muon collider design

    SciTech Connect

    Palmer, R.; Gallardo, J.

    1996-10-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of 4 TeV high luminosity {mu}{sup +}{mu}{sup {minus}} collider, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders.

  3. Results From the DAFNE High Luminosity Test

    SciTech Connect

    Milardi, C.; Alesini, D.; Biagini, M.E.; Boni, R.; Boscolo, M.; Bossi, F.; Buonomo, B.; Clozza, A.; Delle Monache, G.; Demma, T.; Di Pasquale, E.; Di Pirro, G.; Drago, A.; Gallo, A.; Ghigo, A.; Guiducci, S.; Ligi, C.; Marcellini, F.; Mazzitelli, G.; Murtas, F.; Pellegrino, L.; /Frascati /Novosibirsk, IYF /CERN /INFN, Cosenza /INFN, Rome /KEK, Tsukuba /Orsay, LAL /Rome U. /Pisa U. /INFN, Pisa /INFN, Rome3 /SLAC

    2012-04-11

    The DAPHNE collider, based on a new collision scheme including Large Piwinsky angle and Crab-Waist, has been successfully commissioned and is presently delivering luminosity to the SIDDHARTA detector. Large crossing angle and Crab-Waist scheme proved to be effective in: (1) Increasing luminosity, now a factor 2.7 higher than in the past; and (2) controlling transverse beam blow-up due to the beam-beam. Work is in progress to reach the ultimate design luminosity goal 5.0 {center_dot} 10{sup 32} cm{sup -2}s{sup -1}. The new collision scheme is the main design concept for a new project aimed at building a Super-B factory that is expected to achieve a luminosity of the order of 10{sup 36} cm{sup -2} s{sup -1} and it has been also taken into account to upgrade one of the LHC interaction regions.

  4. Tevatron Experimental Issues at High Luminosities

    SciTech Connect

    Kreps, Michal; CDF, for the; collaborations, D0

    2009-12-01

    In this paper we describe the detector components, triggers and analysis techniques for flavor physics at the Tevatron experiments CDF and D0. As Tevatron performs very well and runs at higher luminosities regularly we also touch issues related to it and efforts to improve detectors and triggers for such running.

  5. High luminosity electron-hadron collider eRHIC

    SciTech Connect

    Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

    2011-03-28

    We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

  6. High-field Magnet Development toward the High Luminosity LHC

    SciTech Connect

    Apollinari, Giorgio

    2014-07-01

    The upcoming Luminosity upgrade of the LHC (HL-LHC) will rely on the use of Accelerator Quality Nb3Sn Magnets which have been the focus of an intense R&D effort in the last decade. This contribution will describe the R&D and results of Nb3Sn Accelerator Quality High Field Magnets development efforts, with emphasis on the activities considered for the HL-LHC upgrades.

  7. Fast Frontend Electronics for high luminosity particle detectors

    NASA Astrophysics Data System (ADS)

    Cardinali, M.

    Future experiments of nuclear and particle physics are moving towards the high luminosity regime, in order to access suppressed processes like rare B decays or exotic charmonium resonances. In this scenario, high rate capability is a key requirement for electronics instrumentation, together with excellent timing resolution for precise event reconstruction. The development of dedicated FrontEnd Electronics (FEE) for detectors has become increasingly challenging. A current trend in R&D is towards multipurpose FEE which can be easily adapted to a great variety of detectors, without impairing the required high performance. We report on high-precision timing solutions which utilise high-bandwidth preamplifiers and fast discriminators providing Time-over-Threshold information, which can be used for charge measurements or walk corrections thus improving the obtainable timing resolution. The output signal are LVDS and can be directly fed into a multi-hit TDC readout. The performance of the electronics was investigated for single photon signals, typical for imaging Cherenkov detectors. The opposite condition of light signals arising from plastic scintillators, was also studied. High counting rates per channel of several MHz were achieved, and a timing resolution of better than 100 ps could be obtained in a test experiment using the full readout chain.

  8. Physics of a high-luminosity Tau-Charm Factory

    SciTech Connect

    King, M.E.

    1992-10-01

    This paper highlights the physics capabilities of a Tau-Charm Factory; i.e., high luminosity ({approximately}10{sup 33}cm{sup {minus}2}s{sup {minus}1}) e{sup +}e{sup {minus}} collider operating in the center-of-mass energy range of 3-5 GeV, with a high-precision, general-purpose detector. Recent developments in {tau} and charm physics are emphasized.

  9. OH megamasers in high-luminosity IRAS galaxies

    NASA Technical Reports Server (NTRS)

    Mirabel, I. F.; Sanders, D. B.

    1987-01-01

    OH megamaser emission and H I and CO profiles from the distant infrared galaxies IRAS 10173 + 0828, III Zw 035, and Zw 475.056 are reported. The OH isotropic luminosities at 1667 MHz are 463, 534, and 6.6 solar luminosities, respectively. Far-infrared pumping efficiencies of the OH greater than 1 percent are found in IRAS 10173 + 0828 and III Zw 035. These two galaxies show anomalously large 1667/1665 MHz emission line ratios. OH megamasers reside in the nuclei of superluminous far-infrared galaxies that have a high content of molecular gas, high efficiency of star formation, and in some instances, a striking deficiency of atomic hydrogen.

  10. Dynamic aperture studies for the LHC high luminosity lattice

    SciTech Connect

    Maria, R. de; Giovannozzi, M.; McIntosh, E.; Nosochkov, Y. M.; Cai, Y.; Wang, M. -H.

    2015-07-14

    Since quite some time, dynamic aperture studies have been undertaken with the aim of specifying the required field quality of the new magnets that will be installed in the LHC ring in the framework of the high-luminosity upgrade. In this paper the latest results concerning the specification work will be presented, taking into account both injection and collision energies and the field quality contribution from all the magnets in the newly designed interaction regions.

  11. IUE observations of blue halo high luminosity stars

    NASA Technical Reports Server (NTRS)

    Hack, M.; Franco, M. L.; Stalio, R.

    1981-01-01

    Two high luminosity population II blue stars of high galactic latitude, BD+33 deg 2642 and HD 137569 were observed at high resolution. The stellar spectra show the effect of mass loss in BD+33 deg 2642 and abnormally weak metallic lines in HD 137569. The interstellar lines in the direction of BD+33 deg 2642, which lies at a height z greater than or equal to 6.2 kpc from the galactic plane, are split into two components. No high ionization stages are found at the low velocity component; nor can they be detected in the higher velocity clouds because of mixing with the corresponding stellar/circumstellar lines.

  12. SLHC, the High-Luminosity Upgrade (public event)

    ScienceCinema

    None

    2016-07-12

    In the morning of June 23rd a public event is organised in CERN's Council Chamber with the aim of providing the particle physics community with up-to-date information about the strategy for the LHC luminosity upgrade and to describe the current status of preparation work. The presentations will provide an overview of the various accelerator sub-projects, the LHC physics prospects and the upgrade plans of ATLAS and CMS. This event is organised in the framework of the SLHC-PP project, which receives funding from the European Commission for the preparatory phase of the LHC High Luminosity Upgrade project. Informing the public is among the objectives of this EU-funded project. A simultaneous transmission of this meeting will be broadcast, available at the following address: http://webcast.cern.ch/

  13. Multichannel assault on natural supersymmetry at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Baer, Howard; Barger, Vernon; Savoy, Michael; Tata, Xerxes

    2016-08-01

    Recent clarifications of naturalness in supersymmetry robustly require the presence of four light Higgsinos with mass ˜100 - 300 GeV while gluinos and (top) squarks may lie in the multi-TeV range, possibly out of LHC reach. We project the high-luminosity (300 - 3000 fb-1 ) reach of LHC14 via gluino cascade decays and via same-sign diboson production. We compare these to the reach for neutralino pair production Z˜1Z˜2 followed by Z˜2→Z˜1ℓ+ℓ- decay to soft dileptons which recoil against a hard jet. It appears that 3000 fb-1 is just about enough integrated luminosity to probe naturalness with up to 3% fine-tuning at the 5 σ level, thus either discovering natural supersymmetry or else ruling it out.

  14. Designing the ATLAS trigger menu for high luminosities

    NASA Astrophysics Data System (ADS)

    Nakahama, Yu

    2012-12-01

    The LHC has a bunch-crossing rate of 20 MHz whereas the ATLAS detector has an average recording rate of about 400 Hz. To reduce the rate of events but still maintain a high efficiency for selecting interesting events needed by ATLAS physics analyses, a three-level trigger system is used in ATLAS. Events are selected based on the Trigger Menu, the definitions of the physics signatures the experiment triggers on. In the 2012 data taking since April, approximately 700 chains are used online. The menu must reflect not only the physics goals of the collaboration but also take into consideration the LHC luminosity and the strict DAQ limitations. An overview of the design, the validation and the performance of the trigger menu for the 2011 data-taking is given. During 2011, the menu had to evolve as the luminosity increase from below 2×1033 cm-2s-1 to almost 5×1033 cm-2s-1. Re-designing the menu for the up-coming high luminosity of around 1034 cm-2s-1 and large number of collision events that take place per each bunch crossing (pile-up) of around 35 interactions per bunch crossing at √s = 8 TeV is described. Initial performance in the 2012 data-taking is also reported.

  15. Disc outflows and high-luminosity true type 2 AGN

    NASA Astrophysics Data System (ADS)

    Elitzur, Moshe; Netzer, Hagai

    2016-06-01

    The absence of intrinsic broad-line emission has been reported in a number of active galactic nuclei (AGN), including some with high Eddington ratios. Such `true type 2 AGN' are inherent to the disc-wind scenario for the broad-line region: broad-line emission requires a minimal column density, implying a minimal outflow rate and thus a minimal accretion rate. Here we perform a detailed analysis of the consequences of mass conservation in the process of accretion through a central disc. The resulting constraints on luminosity are consistent with all the cases where claimed detections of true type 2 AGN pass stringent criteria, and predict that intrinsic broad-line emission can disappear at luminosities as high as ˜4 × 1046 erg s-1 and any Eddington ratio, though more detections can be expected at Eddington ratios below ˜1 per cent. Our results are applicable to every disc outflow model, whatever its details and whether clumpy or smooth, irrespective of the wind structure and its underlying dynamics. While other factors, such as changes in spectral energy distribution or covering factor, can affect the intensities of broad emission lines, within this scenario they can only produce true type 2 AGN of higher luminosity then those prescribed by mass conservation.

  16. Quality Factor for the Hadronic Calorimeter in High Luminosity Conditions

    NASA Astrophysics Data System (ADS)

    Seixas, J. M.; ATLAS Tile Calorimeter System

    2015-05-01

    The Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of ATLAS experiment of the Large Hadron Collider (LHC) and has about 10,000 eletronic channels. An Optimal Filter (OF) has been used to estimate the energy sampled by the calorimeter and applies a Quality Factor (QF) for signal acceptance. An approach using Matched Filter (MF) has also been pursued. In order to cope with the luminosity rising foreseen for LHC operation upgrade, different algorithms have been developed. Currently, the OF measurement for signal acceptance is implemented through a chi-square test. At a low luminosity scenario, such QF measurement has been used as a way to describe how the acquired signal is compatible to the pulse shape pattern. However, at high-luminosity conditions, due to pile up, this QF acceptance is no longer possible when OF is employed, and the QF becomes a measurement to indicate whether the reconstructed signal suffers or not from pile up. Methods are being developed in order to recover the superimposed information, and the QF may be used again as signal acceptance criterion. In this work, a new QF measurement is introduced. It is based on divergence statistics, which measures the similarity of probability density functions.

  17. Radiation environment and shielding for a high luminosity collider detector

    SciTech Connect

    Diwan, M.V.; Fisyak, Y.; Mokhov, N.V.

    1995-12-01

    Detectors now under design for use in the proposed high energy high luminosity colliders must deal with unprecedented radiation levels. We have performed a comprehensive study for the GEM detector at the SSC to determine the best way to shield critical detector components from excessive radiation, with special attention paid to the low energy neutrons and photons. We have used several detailed Monte-Carlo simulations to calculate the particle fluxes in the detector. We describe these methods and demonstrate that two orders of magnitude reduction in the neutron and photon fluxes can be obtained with appropriate shielding of critical forward regions such as the low beta quadrupoles and the forward calorimeter.

  18. Long term dynamics of the high luminosity Large Hadron Collider with crab cavities

    NASA Astrophysics Data System (ADS)

    Barranco García, J.; De Maria, R.; Grudiev, A.; Tomás García, R.; Appleby, R. B.; Brett, D. R.

    2016-10-01

    The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) aims to achieve an integrated luminosity of 200 - 300 fb-1 per year, including the contribution from the upgrade of the injector chain. For the HL-LHC the larger crossing angle together with a smaller beta function at the collision point would result in more than 70% luminosity loss due to the incomplete geometric overlap of colliding bunches. To recover head-on collisions at the high-luminosity particle-physics detectors ATLAS and CMS and benefit from the very low β* provided by the Achromatic Telescopic Squeezing (ATS) optics, a local crab cavity scheme provides transverse kicks to the proton bunches. The tight space constraints at the location of these cavities leads to designs which are axially non-symmetric, giving rise to high order multipoles components of the main deflecting mode and, since these kicks are harmonic in time, we expand them in a series of multipoles in a similar fashion as is done for static field magnets. In this work we calculate, for the first time, the higher order multipoles and their impact on beam dynamics for three different crab cavity prototypes. Different approaches to calculate the multipoles are presented. Furthermore, we perform the first calculation of their impact on the long term stability of the machine using the concept of dynamic aperture.

  19. The winds of high luminosity late-type bright stars

    NASA Technical Reports Server (NTRS)

    Stencel, Robert E.; Carpenter, K. G.

    1989-01-01

    The occurrence and characteristics of the Fe II line asymmetries were studied to determine the radial dependence of the wind velocity for each star. The dependence of the Fe II profiles on spectral type and luminosity class and thus the variation of the velocity fields with stellar type was also investigated. This allows the generality of the results reported for alpha Ori by Carpenter (1984b) to be judged. In addition, new atomic data was used along with observations of the C II (UV 0.01) multiplet to estimate N(sub e) in the stellar winds. Measures of relative Fe II fluxes can be used in a probability-of-escape model to determine the opacity and hydrogen column density versus height in the chromosphere of each star. Finally, analysis of the fluorescent Fe II lines (pumped by Ly alpha) near 2507 A will yield estimates of the intrinsic stellar Ly alpha flux that cannot be measured directly because of interstellar and circumstellar absorption. One important goal of the effort was to acquire high resolution spectra of the whole 2300 to 3200 A region of 13 luminous K and M stars as a data base that will be enormously valuable in planning observations with the Hubble Space Telescope High Resolution Spectrograph. It is also proposed to follow up the recent discovery of significant variations in the Fe II chromospheric emission line profiles from the M-giant Gamma Cru for the purpose of determining the underlying cause of the variations.

  20. Poor Results for High Achievers

    ERIC Educational Resources Information Center

    Bui, Sa; Imberman, Scott; Craig, Steven

    2012-01-01

    Three million students in the United States are classified as gifted, yet little is known about the effectiveness of traditional gifted and talented (G&T) programs. In theory, G&T programs might help high-achieving students because they group them with other high achievers and typically offer specially trained teachers and a more advanced…

  1. Detector Developments for the High Luminosity LHC Era (1/4)

    ScienceCinema

    None

    2016-07-12

    Calorimetry and Muon Spectrometers - Part I : In the first part of the lecture series, the motivation for a high luminosity upgrade of the LHC will be quickly reviewed together with the challenges for the LHC detectors. In particular, the plans and ongoing research for new calorimeter detectors will be explained. The main issues in the high-luminosity era are an improved radiation tolerance, natural ageing of detector components and challenging trigger and physics requirements. The new technological solutions for calorimetry at a high-luminosity LHC will be reviewed.

  2. Detector Developments for the High Luminosity LHC Era (1/4)

    SciTech Connect

    2010-09-22

    Calorimetry and Muon Spectrometers - Part I : In the first part of the lecture series, the motivation for a high luminosity upgrade of the LHC will be quickly reviewed together with the challenges for the LHC detectors. In particular, the plans and ongoing research for new calorimeter detectors will be explained. The main issues in the high-luminosity era are an improved radiation tolerance, natural ageing of detector components and challenging trigger and physics requirements. The new technological solutions for calorimetry at a high-luminosity LHC will be reviewed.

  3. A high-energy high-luminosity {mu}{sup +} {minus} {mu}{sup {minus}} collider

    SciTech Connect

    Neuffer, D.V.; Palmer, R.

    1994-06-01

    We present a candidate design for a high-energy high luminosity {mu}{sup +}-{mu} collider, with E{sub cm} = 4 TeV, L = 10{sup 34} cm{sup {minus}2}S{sup {minus}1}, using only existing technology. The design uses a rapid-cycling medium-energy proton synchrotron, which produces proton beam pulses which are focused onto two {pi}- producing targets, with two {pi}-decay transport lines producing {mu}{sup +}{prime}s and {mu}{sup {minus}}{prime}. The {mu}{prime}s are collected, rf-rotated, cooled and compressed into a recirculating linac for acceleration, and then transferred into a storage ring collider. The keys to high luminosity are maximal {mu} collection and cooling; innovations with these goals are included.

  4. Recent Progress on Design Studies of High-Luminosity Ring-Ring Electron-Ion Collider at CEBAF

    SciTech Connect

    Zhang, Y; Bruell, A; Chevtsov, P; Derbenev, Y S; Ent, R; Krafft, G A; Li, R; Merminga, L; Yunn, B C

    2009-05-01

    The conceptual design of a ring-ring electron-ion collider based on CEBAF has been continuously optimized to cover a wide center-of-mass energy region and to achieve high luminosity and polarization to support next generation nuclear science programs. Here, we summarize the recent design improvements and R&D progress on interaction region optics with chromatic aberration compensation, matching and tracking of electron polarization in the Figure-8 ring, beam-beam simulations and ion beam cooling studies.

  5. Overview of a high luminosity {mu}{sup +}{mu}{sup {minus}} collider

    SciTech Connect

    Palmer, R.B.; Gallardo, J.C.

    1997-03-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of a 4 TeV high luminosity {mu}{sup +}{mu}{sup {minus}} collider, and of a 0.5 TeV lower luminosity demonstration machine. The authors discuss the various systems in such muon colliders.

  6. Optical Variability of Two High-Luminosity Radio-Quiet Quasars, PDS 456 and PHL 1811

    NASA Astrophysics Data System (ADS)

    Gaskell, C. M.; Benker, A. J.; Campbell, J. S.; Crowley, K. A.; George, T. A.; Hedrick, C. H.; Hiller, M. E.; Klimek, E. S.; Leonard, J. P.; Peterson, B. W.; Sanders, K. M.

    2003-12-01

    PDS 456 and PHL 1811 are two of the highest luminosity low-redshift quasars. Both have optical luminosities comparable to 3C 273, but they have low radio luminosities. PDS 456 is a broad line object but PHL 1811 could be classified as a high-luminosity Narrow-Line Seyfert 1 (NLS1) object. We present the results of optical (V-band) continuum monitoring of PDS 456 and PHL 1811. We compare the variability properties of these two very different AGNs compared with the radio-loud AGN 3C 273, and we discuss the implications for the origin of the optical continuum variability in AGNs. This research has been supported in part by the Howard Hughes Foundation, Nebraska EPSCoR, the University of Nebraska Layman Fund, the University of Nebraska Undergraduate Creative Activities and Research Experiences, Pepsi-Cola, and the National Science Foundation through grant AST 03-07912.

  7. Extra-galactic high-energy transients: event rate density and luminosity function

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Zhang, Bing; Li, Zhuo

    2015-08-01

    Several types of extra-galactic high-energy transients have been discovered, which include high-luminosity and low-luminosity long-duration gamma-ray bursts (GRBs), short-duration GRBs, supernova shock breakouts (SBOs), and tidal disruption events (TDEs) without or with a relativistic jet. In this paper, we apply a unified method to systematically study the reshift-dependent event rate densities and luminosity functions of these extra-galactic high-energy transients. We consider star formation history as the tracer of the redshift distribution for long GRBs and SBOs. For short GRBs, we consider the compact star merger model to introduce several possible merger delay time distribution models. For TDEs, we consider the mass distribution of supermassive black holes as a function of redshift. We derive some empirical formulae for the redshift-dependent event rate density for different types of transients. Based on the observed events, we derive the local specific event rate density, ρ0,L ∝ dρ0/dL for each type of transient, which represents its luminosity function. All the transients are consistent with having a single power law luminosity function, except the high luminosity long GRBs (HL-lGRBs), whose luminosity function can be well described by a broken power law. The total event rate density for a particular transient depends on the luminosity threshold, and we obtain the following values in units of Gpc-3 yr-1: 2.82^{+0.41}_{-0.36} for HL-lGRBs above 4×1049 erg s-1 218^{+130}_{-86} for low luminosity long GRBs above 6×1046 erg s-1 3.18^{+0.88}_{-0.70}, 2.87^{+0.80}_{-0.64}, and 6.25^{+1.73}_{-1.38} above 5×1049 erg s-1 for short GRBs with three different merger delay models (Gaussian, log-normal, and power law); 2.0^{+2.6}_{-1.3}×104 above 9×1043 erg s-1 for SBOs, 3.0^{+1.0}_{-0.8}×105 for normal TDEs above 1042 erg s-1 and 6.2^{+8.2}_{-4.0} above 3×1047 erg s-1for TDE jets as discovered by Swift. Intriguingly, the global specific event rate densities

  8. Morphology of high-luminosity compact radio sources.

    PubMed Central

    Zensus, J A; Krichbaum, T P; Lobanov, A P

    1995-01-01

    High-dynamic range imaging and monitoring with very-long-baseline interferometry reveal a rich morphology of luminous flat-spectrum radio sources. One-sided core-jet structures abound, and superluminal motion is frequently measured. In a few cases, both distinct moving features and diffuse underlying jet emission can be detected. Superluminal motion seen in such sources is typically complex, on curved trajectories or ridge lines, and with variable component velocities, including stationary features. The curved trajectories seen can be modeled by helical motion within the underlying jet flow. The very-long-baseline interferometry properties of the superluminal features in the jet of 3C 345 and other similar sources can be explained by models invoking the emission from shocks, at least within the vicinity of the compact core. Inverse-Compton calculations, constrained by x-ray observations, yield realistic estimates for the physical conditions in the parsec-scale jet. There is evidence for a transition region in this source beyond which other factors (e.g., plasma interactions and nonsynchrotron radiation processes) may become prominent. Multifrequency and polarization imaging (especially at high frequencies) are emerging as critical tools in testing model predictions. PMID:11607595

  9. Morphology of high-luminosity compact radio sources.

    PubMed

    Zensus, J A; Krichbaum, T P; Lobanov, A P

    1995-12-01

    High-dynamic range imaging and monitoring with very-long-baseline interferometry reveal a rich morphology of luminous flat-spectrum radio sources. One-sided core-jet structures abound, and superluminal motion is frequently measured. In a few cases, both distinct moving features and diffuse underlying jet emission can be detected. Superluminal motion seen in such sources is typically complex, on curved trajectories or ridge lines, and with variable component velocities, including stationary features. The curved trajectories seen can be modeled by helical motion within the underlying jet flow. The very-long-baseline interferometry properties of the superluminal features in the jet of 3C 345 and other similar sources can be explained by models invoking the emission from shocks, at least within the vicinity of the compact core. Inverse-Compton calculations, constrained by x-ray observations, yield realistic estimates for the physical conditions in the parsec-scale jet. There is evidence for a transition region in this source beyond which other factors (e.g., plasma interactions and nonsynchrotron radiation processes) may become prominent. Multifrequency and polarization imaging (especially at high frequencies) are emerging as critical tools in testing model predictions.

  10. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    SciTech Connect

    Fartoukh, Stephane; Valishev, Alexander; Shatilov, Dmitry

    2015-06-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  11. Nb$_3$Sn High Field Magnets for the High Luminosity LHC Upgrade Project

    SciTech Connect

    Ambrosio, Giorgio

    2015-01-01

    The High Luminosity upgrade of the Large Hadron Collider at CERN requires a new generation of high field superconducting magnets. High field large aperture quadrupoles (MQXF) are needed for the low-beta triplets close to the ATLAS and CMS detectors, and high field two-in-one dipoles (11 T dipoles) are needed to make room for additional collimation. The MQXF quadrupoles, with a field gradient of 140 T/m in 150 mm aperture, have a peak coil field of 12.1 T at nominal current. The 11 T dipoles, with an aperture of 60 mm, have a peak coil field of 11.6 T at nominal current. Both magnets require Nb3Sn conductor and are the first applications of this superconductor to actual accelerator magnets.

  12. High luminosity {mu}{sup +} {mu}{sup {minus}} collider: Report of a feasibility study

    SciTech Connect

    Palmer, R.B.; Gallardo, J.C.; Tollestrup, A.; Sessler, A.

    1996-12-01

    Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity {mu}{sup +}{mu}{sup -} colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. We briefly mention the luminosity requirements of hadrons and lepton machines and their high-energy-physics advantages and disadvantages in reference to their effective center of mass energy. Finally, we present an R & D plan to determine whether such machines are practical.

  13. Mathematics Achievement in High- and Low-Achieving Secondary Schools

    ERIC Educational Resources Information Center

    Mohammadpour, Ebrahim; Shekarchizadeh, Ahmadreza

    2015-01-01

    This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the…

  14. Final Cooling For a High-luminosity High-Energy Lepton Collider

    SciTech Connect

    Neuffer, D.; Sayed, H.; Hart, T.; Summers, D.

    2015-05-01

    The final cooling system for a high-energy high-luminosity heavy lepton collider requires reduction of the transverse emittance εt by an order of magnitude to ~0.00003 m (rms, N), while allowing longitudinal emittance εL to increase to ~0.1m. In the present baseline approach, this is obtained by transverse cooling of low-energy muons within a sequence of high-field solenoids with low-frequency rf systems. Recent studies of such systems are presented. Since the final cooling steps are mostly emittance exchange, a variant form of that final system can be obtained by a round to flat transform in x-y, with transverse slicing of the enlarged flat transverse dimension followed by longitudinal recombination of the sliced bunchlets. Other variants are discussed. More explicit emittance exchange can greatly reduce the cost of a final cooling system.

  15. Cryogenic test of double quarter wave crab cavity for the LHC High luminosity upgrade

    SciTech Connect

    Xiao, B.; Alberty, L.; Belomestnykh, S.; Ben-Zvi, I.; Calaga, R.; Cullen, C.; Capatina, O.; Hammons, L.; Li, Z.; Marques, C.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Proof-of-Principle (PoP) Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. A vertical cryogenic test has been done at Brookhaven National Lab (BNL). The cavity achieved 4.5 MV deflecting voltage with a quality factor above 3×109. We report the test results of this design.

  16. A physical model for the evolving ultraviolet luminosity function of high redshift galaxies and their contribution to the cosmic reionization

    SciTech Connect

    Cai, Zhen-Yi; Lapi, Andrea; Bressan, Alessandro; De Zotti, Gianfranco; Danese, Luigi; Negrello, Mattia

    2014-04-10

    We present a physical model for the evolution of the ultraviolet (UV) luminosity function of high-redshift galaxies, taking into account in a self-consistent way their chemical evolution and the associated evolution of dust extinction. Dust extinction is found to increase fast with halo mass. A strong correlation between dust attenuation and halo/stellar mass for UV selected high-z galaxies is thus predicted. The model yields good fits of the UV and Lyman-α (Lyα) line luminosity functions at all redshifts at which they have been measured. The weak observed evolution of both luminosity functions between z = 2 and z = 6 is explained as the combined effect of the negative evolution of the halo mass function; of the increase with redshift of the star formation efficiency due to the faster gas cooling; and of dust extinction, differential with halo mass. The slope of the faint end of the UV luminosity function is found to steepen with increasing redshift, implying that low luminosity galaxies increasingly dominate the contribution to the UV background at higher and higher redshifts. The observed range of the UV luminosities at high z implies a minimum halo mass capable of hosting active star formation M {sub crit} ≲ 10{sup 9.8} M {sub ☉}, which is consistent with the constraints from hydrodynamical simulations. From fits of Lyα line luminosity functions, plus data on the luminosity dependence of extinction, and from the measured ratios of non-ionizing UV to Lyman-continuum flux density for samples of z ≅ 3 Lyman break galaxies and Lyα emitters, we derive a simple relationship between the escape fraction of ionizing photons and the star formation rate. It implies that the escape fraction is larger for low-mass galaxies, which are almost dust-free and have lower gas column densities. Galaxies already represented in the UV luminosity function (M {sub UV} ≲ –18) can keep the universe fully ionized up to z ≅ 6. This is consistent with (uncertain) data

  17. Extragalactic High-energy Transients: Event Rate Densities and Luminosity Functions

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Zhang, Bing; Li, Zhuo

    2015-10-01

    Several types of extragalactic high-energy transients have been discovered, which include high-luminosity and low-luminosity long-duration gamma-ray bursts (GRBs), short-duration GRBs, supernova shock breakouts (SBOs), and tidal disruption events (TDEs) without or with an associated relativistic jet. In this paper, we apply a unified method to systematically study the redshift-dependent event rate densities and the global luminosity functions (GLFs; ignoring redshift evolution) of these transients. We introduce some empirical formulae for the redshift-dependent event rate densities for different types of transients and derive the local specific event rate density, which also represents its GLF. Long GRBs (LGRBs) have a large enough sample to reveal features in the GLF, which is best charaterized as a triple power law (PL). All the other transients are consistent with having a single-power-law (SPL) LF. The total event rate density depends on the minimum luminosity, and we obtain the following values in units of Gpc‑3 yr‑1: {0.8}-0.1+0.1 for high-luminosity LGRBs above 1050 erg s‑1 {164}-65+98 for low-luminosity LGRBs above 5 × 1046 erg s‑1 {1.3}-0.3+0.4, {1.2}-0.3+0.4, and {3.3}-0.8+1.0 above 1050 erg s‑1 for short GRBs with three different merger delay models (Gaussian, lognormal, and PL); {1.9}-1.2+2.4× {10}4 above 1044 erg s‑1 for SBOs, {4.8}-2.1+3.2× {10}2 for normal TDEs above 1044 erg s‑1 and {0.03}-0.02+0.04 above 1048 erg s‑1 for TDE jets as discovered by Swift. Intriguingly, the GLFs of different kinds of transients, which cover over 12 orders of magnitude, are consistent with an SPL with an index of ‑1.6.

  18. Extragalactic High-energy Transients: Event Rate Densities and Luminosity Functions

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Zhang, Bing; Li, Zhuo

    2015-10-01

    Several types of extragalactic high-energy transients have been discovered, which include high-luminosity and low-luminosity long-duration gamma-ray bursts (GRBs), short-duration GRBs, supernova shock breakouts (SBOs), and tidal disruption events (TDEs) without or with an associated relativistic jet. In this paper, we apply a unified method to systematically study the redshift-dependent event rate densities and the global luminosity functions (GLFs; ignoring redshift evolution) of these transients. We introduce some empirical formulae for the redshift-dependent event rate densities for different types of transients and derive the local specific event rate density, which also represents its GLF. Long GRBs (LGRBs) have a large enough sample to reveal features in the GLF, which is best charaterized as a triple power law (PL). All the other transients are consistent with having a single-power-law (SPL) LF. The total event rate density depends on the minimum luminosity, and we obtain the following values in units of Gpc-3 yr-1: {0.8}-0.1+0.1 for high-luminosity LGRBs above 1050 erg s-1 {164}-65+98 for low-luminosity LGRBs above 5 × 1046 erg s-1 {1.3}-0.3+0.4, {1.2}-0.3+0.4, and {3.3}-0.8+1.0 above 1050 erg s-1 for short GRBs with three different merger delay models (Gaussian, lognormal, and PL); {1.9}-1.2+2.4× {10}4 above 1044 erg s-1 for SBOs, {4.8}-2.1+3.2× {10}2 for normal TDEs above 1044 erg s-1 and {0.03}-0.02+0.04 above 1048 erg s-1 for TDE jets as discovered by Swift. Intriguingly, the GLFs of different kinds of transients, which cover over 12 orders of magnitude, are consistent with an SPL with an index of -1.6.

  19. High-luminosity single carbon stars in stellar and galactic evolution

    NASA Technical Reports Server (NTRS)

    Jura, M.

    1991-01-01

    In the solar neighborhood, approximately half of all intermediate mass main sequence stars with initially between 1 solar mass and about 5 solar masses become carbon stars with luminosities near 10,000 lunar luminosities for typically less than 1 million years. These high luminosity carbon stars lose mass at rates nearly always in excess of 10 to the -7th solar mass/yr and sometimes in excess of 0.00001 solar mass/yr. Locally, close to half of the mass returned into the interstellar medium by intermediate mass stars before they become white dwarfs is during the carbon star phase. A much greater fraction of lower metallicity stars become carbon-rich before they evolve into planetary nebulae, than do higher-metallicity stars; therefore, carbon stars are much more important in the outer than in the inner Galaxy.

  20. Detector Developments for the High Luminosity LHC Era (3/4)

    ScienceCinema

    None

    2016-07-12

    Tracking Detectors - Part I. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  1. Detector Developments for the High Luminosity LHC Era (4/4)

    ScienceCinema

    None

    2016-07-12

    Tracking Detectors - Part II. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

  2. Populations of High-Luminosity Density-Bounded HII Regions in Spiral Galaxies? Evidence and Implications

    NASA Technical Reports Server (NTRS)

    Beckman, J. E.; Rozas, M.; Zurita, A.; Watson, R. A.; Knapen, J. H.

    2000-01-01

    In this paper we present evidence that the H II regions of high luminosity in disk galaxies may be density bounded, so that a significant fraction of the ionizing photons emitted by their exciting OB stars escape from the regions. The key piece of evidence is the presence, in the Ha luminosity functions (LFs) of the populations of H iI regions, of glitches, local sharp peaks at an apparently invariant luminosity, defined as the Stromgren luminosity Lstr), LH(sub alpha) = Lstr = 10(sup 38.6) (+/- 10(sup 0.1)) erg/ s (no other peaks are found in any of the LFs) accompanying a steepening of slope for LH(sub alpha) greater than Lstr This behavior is readily explicable via a physical model whose basic premises are: (a) the transition at LH(sub alpha) = Lstr marks a change from essentially ionization bounding at low luminosities to density bounding at higher values, (b) for this to occur the law relating stellar mass in massive star-forming clouds to the mass of the placental cloud must be such that the ionizing photon flux produced within the cloud is a function which rises more steeply than the mass of the cloud. Supporting evidence for the hypothesis of this transition is also presented: measurements of the central surface brightnesses of H II regions for LH(sub alpha) less than Lstr are proportional to L(sup 1/3, sub H(sub alpha)), expected for ionization bounding, but show a sharp trend to a steeper dependence for LH(sub alpha) greater than Lstr, and the observed relation between the internal turbulence velocity parameter, sigma, and the luminosity, L, at high luminosities, can be well explained if these regions are density bounded. If confirmed, the density-bounding hypothesis would have a number of interesting implications. It would imply that the density-bounded regions were the main sources of the photons which ionize the diffuse gas in disk galaxies. Our estimates, based on the hypothesis, indicate that these regions emit sufficient Lyman continuum not only to

  3. Radiative return capabilities of a high-energy, high-luminosity e+e- collider

    NASA Astrophysics Data System (ADS)

    Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; Wang, Lian-Tao

    2015-08-01

    An electron-positron collider operating at a center-of-mass energy ECM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at ECM=250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e+e- colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavy flavor spectroscopy are given.

  4. Beam performance and luminosity limitations in the high-energy storage ring (HESR)

    NASA Astrophysics Data System (ADS)

    Lehrach, A.; Boine-Frankenheim, O.; Hinterberger, F.; Maier, R.; Prasuhn, D.

    2006-06-01

    The high-energy storage ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an antiproton synchrotron storage ring in the momentum range 1.5-15 GeV/ c. An important feature of this new facility is the combination of phase space cooled beams and dense internal targets (e.g. pellet targets), which results in demanding beam parameter requirements for two operation modes: high luminosity mode with peak luminosities to 2×10 32 cm -2 s -1, and high-resolution mode with a momentum spread down to 10 -5. To reach these beam parameters one needs a very powerful phase space cooling, utilizing high-energy electron cooling and high-bandwidth stochastic cooling. The effects of beam-target scattering and intra-beam interaction are investigated in order to study beam equilibria and beam losses for the two different operation modes.

  5. Attaining high luminosity in linear e sup + e sup minus colliders

    SciTech Connect

    Palmer, R.B.

    1990-11-01

    The attainment of high luminosity in linear colliders is a complex problem because of the interdependence of the critical parameters. For instance, changing the number of particles per bunch affects the damping ring design and thus the emittance; it affects the wakefields in the linac and thus the momentum spread; the momentum spread affects the final focus design and thus the final {beta}*; but the emittance change also affects the final focus design; and all these come together to determine the luminosity, disruption and beamstrahlung at the intersection. Changing the bunch length, or almost any other parameter, has a similar chain reaction. Dealing with this problem by simple scaling laws is very difficult because one does not know which parameter is going to be critical, and thus which should be held constant. One can only maximize the luminosity by a process of search and iteration. The process can be facilitated with the aid of a computer program. Examples can then be optimized for maximum luminosity, and compared to the optimized solutions with different approaches. This paper discusses these approaches.

  6. Long Term Optical and Infrared Reverberation Mapping of High and Low Luminosity Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Gorjian, Varoujan; Barth, Aaron; Brandt, Niel; Dawson, Kyle; Green, Paul; Ho, Luis; Horne, Keith; Jiang, Linhua; Joner, Mike; Kenney, John; McGreer, Ian; Nordgren, Tyler; Schneider, Donald; Shen, Yue; Tao, Charling

    2016-08-01

    Previous Spitzer reverberation monitoring projects looking for UV/optical light absorbed and re-emitted in the IR by dust have been limited to very low luminosity active galactic nuclei (AGN) that could potentially show reverberation within a single cycle (~1 year). Cycle 11-12's two year baseline allowed for the reverberation mapping of 17 high luminosity quasars from the Sloan Digital Sky Survey Reverberation Mapping project. By combining ground based monitoring from Pan-STARRS, CFHT, and Steward Observatory telescopes with Spitzer data we have for the first time detected dust reverberation in quasars. We propose to continue this project to capitalize on the continuing optical motnoring from the ground and to increase the confidence in the detected lags. Additionally, the Call for Proposals asks for up to 1000 hours of observations in the Spitzer CVZ to accommodate battery charging needs. We propose to add to our quasar sample five lower luminosity Seyfert galaxies from the Pan-STARRS ground based optical survey that are in the Spitzer CVZ, which will increase the luminosity range of AGN we are studying and, combined with additional ground based observatories, provide for a continuous monitoring campaign lasting 2 years and thus provide the most detailed study of dust around AGN to date.

  7. High-energy high-luminosity electron-ion collider eRHIC

    SciTech Connect

    Litvinenko, V.N.; Ben-Zvi, I.; Hammons, L.; Hao, Y.; Webb, S.; et al

    2011-08-09

    In this paper, we describe a future electron-ion collider (EIC), based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. The replacement cost of the RHIC facility is about two billion US dollars, and the eRHIC will fully take advantage and utilize this investment. We plan adding a polarized 5-30 GeV electron beam to collide with variety of species in the existing RHIC accelerator complex, from polarized protons with a top energy of 325 GeV, to heavy fully-striped ions with energies up to 130 GeV/u. Brookhaven's innovative design, is based on one of the RHIC's hadron rings and a multi-pass energy-recovery linac (ERL). Using the ERL as the electron accelerator assures high luminosity in the 10{sup 33}-10{sup 34} cm{sup -2} sec{sup -1} range, and for the natural staging of eRHIC, with the ERL located inside the RHIC tunnel. The eRHIC will provide electron-hadron collisions in up to three interaction regions. We detail the eRHIC's performance in Section 2. Since first paper on eRHIC paper in 2000, its design underwent several iterations. Initially, the main eRHIC option (the so-called ring-ring, RR, design) was based on an electron ring, with the linac-ring (LR) option as a backup. In 2004, we published the detailed 'eRHIC 0th Order Design Report' including a cost-estimate for the RR design. After detailed studies, we found that an LR eRHIC has about a 10-fold higher luminosity than the RR. Since 2007, the LR, with its natural staging strategy and full transparency for polarized electrons, became the main choice for eRHIC. In 2009, we completed technical studies of the design and dynamics for MeRHIC with 3-pass 4 GeV ERL. We learned much from this evaluation, completed a bottom-up cost estimate for this $350M machine, but then shelved the design. In the same year, we turned again to considering the cost-effective, all-in-tunnel six-pass ERL for our design of the high-luminosity

  8. The New Transfer Line Collimation System for the LHC High Luminosity Era

    SciTech Connect

    Kain, Verena; Bracco, Chiara; Goddard, Brennan; Maciariello, Fausto; Meddahi, Malika; Mereghetti, Alessio; Steele, Genevieve; Velotti, Francesco; Gianfelice-Wendt, Eliana

    2014-07-01

    A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.

  9. The Physics Program of a High-Luminosity Asymmetric B Factory at SLAC

    SciTech Connect

    Eisner, A.; Mandelkern, M.; Morrison, R.; Witherell, M.; Burchat, P.; Kent, J.; Erbacher, R.; Vernon, W.; Eigen, G.; Hitlin, D.; Porter, F.; Weinstein, A.; Wisniewski, W.; Wagner, S.; Franzini, P.; Tuts, M.; Averill, D.; Snyder, A.; Goldhaber, G.; Oddone, P.; Roe, N.; Ronan, M.; Spahn, M.; MacFarlane, D.; Bartelt, J.; Bloom, E.; Bulos, F.; Cords, D.; Dib, C.; Dorfan, J.; Dunietz, I.; Gilman, F.; Godfrey, G.; Hyer, T.; Jensen, G.; Leith, D.; Marsiske, H.; Nir, Y.; Lee-Franzini, J.

    1989-10-01

    A high-luminosity asymmetric energy B Factory, proposed as an upgrade to the PEP storage ring at SLAC, provides the best opportunity to study CP violation as a means of testing the consistency of the Standard Model. If the phenomenon of CP violation is xplained by the Standard Model simply through the non-zero angles and phase of the Kobayashi-Maskawa matrix, then there are precise relations between the K-M parameters and the various measurable CP-violating asymmetries in B meson decay. Should these onsistency relations fail, the origin of CP violation must lie outside the Standard Model framework. Our measurements would then lead to the first experiment-driven extensions of the Standard Model. The B Factory will also carry out a varied, high-quality program of studies f other aspects of the physics of b quarks, as well as high-precision measurements in r and charm physics. We describe a detailed series of measurements to be carried out in the first few years at a peak luminosity of 3 x 10{sup 33} cm{sup -2}sec{sup -1}, the initial luminosity goal of the B Factory, as well as the program accessible to a larger data sample.

  10. Gas dynamics in high-luminosity polarized He-3 targets using diffusion and convection

    SciTech Connect

    Dolph, P.A. M; Averett, T; Kelleher, A; Mooney, K E; Nelyubin, V; Tobias, W A; Wojsekhowski, B; Cates, G D

    2011-12-01

    The dynamics of the movement of gas is discussed for two-chambered polarized He-3 target cells of the sort that have been used successfully for many electron scattering experiments. A detailed analysis is presented showing that diffusion is a limiting factor in target performance, particularly as these targets are run at increasingly high luminosities. Measurements are presented on a new prototype polarized He-3 target cell in which the movement of gas is due largely to convection instead of diffusion. NMR tagging techniques have been used to visualize the gas flow, showing velocities along a cylindrically-shaped target of between 5-80 cm/min. The new target design addresses one of the principle obstacles to running polarized He-3 targets at substantially higher luminosities while simultaneously providing new flexibility in target geometry.

  11. Status report of a high luminosity muon collider and future research and development plans

    SciTech Connect

    Palmer, R.B.; Tollestrup, A.; Sessler, A.

    1996-11-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity {mu}{sup +}{mu}{sup -} colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Finally, we present an R & D plan to determine whether such machines are practical, and, if they are, lead to the construction of a 0.5 TeV demonstration by 2010, and to a 4 TeV collider by the year 2020.

  12. Design of High Luminosity Ring-Ring Electron- Light Ion Collider at CEBAF

    SciTech Connect

    Slawomir Bogacz; Antje Bruell; Jean Delayen; Yaroslav Derbenev; Rolf Ent; Joseph Grames; Andrew Hutton; Geoffrey Krafft; Rui Li; Nikolitsa Merminga; Benard Poelker; Bogdan Wojtsekhowski; Byung Yunn; Yuhong Zhang; C Montag

    2007-06-25

    Experimental studies of fundamental structure of nucleons require an electron-ion collider of a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 with both beams polarized. A CEBAF-based collider of 9 GeV electrons/positrons and 225 GeV ions is envisioned to meet this science need and as a next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. A ring-ring scheme of this collider developed recently takes advantage of the existing polarized electron CW beam from the CEBAF and a green-field design of an ion complex with electron cooling. We present a conceptual design and report design studies of this high-luminosity collider.

  13. Mechanical Analysis of the 400 MHz RF-Dipole Crabbing Cavity Prototype for LHC High Luminosity Upgrade

    SciTech Connect

    De Silva, Subashini U.; Park, HyeKyoung; Delayen, Jean R.; Li, Z.

    2013-12-01

    The proposed LHC high luminosity upgrade requires two crabbing systems in increasing the peak luminosity, operating both vertically and horizontally at two interaction points of IP1 and IP5. The required system has tight dimensional constraints and needs to achieve higher operational gradients. A proof-of-principle 400 MHz crabbing cavity design has been successfully tested and has proven to be an ideal candidate for the crabbing system. The cylindrical proof-of-principle rf-dipole design has been adapted in to a square shaped design to further meet the dimensional requirements. The new rf-dipole design has been optimized in meeting the requirements in rf-properties, higher order mode damping, and multipole components. A crabbing system in a cryomodule is expected to be tested on the SPS beam line prior to the test at LHC. The new prototype is required to achieve the mechanical and thermal specifications of the SPS test followed by the test at LHC. This paper discusses the detailed mechanical and thermal analysis in minimizing Lorentz force detuning and sensitivity to liquid He pressure fluctuations.

  14. IS THE OBSERVED HIGH-FREQUENCY RADIO LUMINOSITY DISTRIBUTION OF QSOs BIMODAL?

    SciTech Connect

    Mahony, Elizabeth K.; Sadler, Elaine M.; Croom, Scott M.; Murphy, Tara; Ekers, Ronald D.; Feain, Ilana J.

    2012-07-20

    The distribution of QSO radio luminosities has long been debated in the literature. Some argue that it is a bimodal distribution, implying that there are two separate QSO populations (normally referred to as 'radio-loud' and 'radio-quiet'), while others claim it forms a more continuous distribution characteristic of a single population. We use deep observations at 20 GHz to investigate whether the distribution is bimodal at high radio frequencies. Carrying out this study at high radio frequencies has an advantage over previous studies as the radio emission comes predominantly from the core of the active galactic nucleus, and hence probes the most recent activity. Studies carried out at lower frequencies are dominated by the large-scale lobes where the emission is built up over longer timescales (10{sup 7}-10{sup 8} yr), thereby confusing the sample. Our sample comprises 874 X-ray-selected QSOs that were observed as part of the 6dF Galaxy Survey. Of these, 40% were detected down to a 3{sigma} detection limit of 0.2-0.5 mJy. No evidence of bimodality is seen in either the 20 GHz luminosity distribution or in the distribution of the R{sub 20} parameter: the ratio of the radio to optical luminosities traditionally used to classify objects as being either radio-loud or radio-quiet. Previous results have claimed that at low radio luminosities, star formation processes can dominate the radio emission observed in QSOs. We attempt to investigate these claims by stacking the undetected sources at 20 GHz and discuss the limitations in carrying out this analysis. However, if the radio emission was solely due to star formation processes, we calculate that this corresponds to star formation rates ranging from {approx}10 M{sub Sun} yr{sup -1} to {approx}2300 M{sub Sun} yr{sup -1}.

  15. L1Track: A fast Level 1 track trigger for the ATLAS high luminosity upgrade

    NASA Astrophysics Data System (ADS)

    Cerri, Alessandro

    2016-07-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware-based ATLAS trigger stage ("Level 1") will have to provide a higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and high accuracy tracking information in time for the decision taking process. In this context, the feasibility of potential approaches aimed at providing low-latency high-quality tracking at Level 1 is discussed.

  16. Energy deposition studies for the high-luminosity Large Hadron Collider inner triplet magnets

    NASA Astrophysics Data System (ADS)

    Mokhov, N. V.; Rakhno, I. L.; Tropin, I. S.; Cerutti, F.; Esposito, L. S.; Lechner, A.

    2015-05-01

    A detailed model of the high-luminosity LHC inner triplet region with new large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented tungsten inner absorbers was built and implemented into the fluka and mars15 codes. Detailed simulations have been performed coherently with the codes on the impact of particle debris from the 14-TeV center-of-mass pp-collisions on the short- and long-term stability of the inner triplet magnets. After optimizing the absorber configuration, the peak power density averaged over the magnet inner cable width is found to be safely below the quench limit at the luminosity of 5 ×1034 cm-2 s-1 . For the anticipated lifetime integrated luminosity of 3000 fb-1 , the peak dose calculated for the innermost magnet insulator ranges from 20 to 35 MGy, a figure close to the commonly accepted limit. Dynamic heat loads to the triplet magnet cold mass are calculated to evaluate the cryogenic capability. fluka and mars results on energy deposition are in very good agreement.

  17. The Abundance of Low-Luminosity Lyα Emitters at High Redshift

    NASA Astrophysics Data System (ADS)

    Santos, Michael R.; Ellis, Richard S.; Kneib, Jean-Paul; Richard, Johan; Kuijken, Konrad

    2004-05-01

    We derive the luminosity function of high-redshift Lyα-emitting sources from a deep, blind, spectroscopic survey that utilized strong-lensing magnification by intermediate-redshift clusters of galaxies. We observed carefully selected regions near nine clusters, consistent with magnification factors generally greater than 10 for the redshift range 4.5luminosity function to unprecedented limits of 1040 ergs s -1, corresponding to a star formation rate of 0.01 Msolar yr-1. Our cumulative z~=5 Lyα luminosity function is consistent with a power-law form n(>L)~L-1 over 1041-1042.5 ergs s-1. When combined with the results of other surveys, limited at higher luminosities, our results suggest evidence for the suppression of star formation in low-mass halos, as predicted in popular models of galaxy formation. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  18. Self Regulated Learning of High Achievers

    ERIC Educational Resources Information Center

    Rathod, Ami

    2010-01-01

    The study was conducted on high achievers of Senior Secondary school. Main objectives were to identify the self regulated learners among the high achievers, to find out dominant components and characteristics operative in self regulated learners and to compare self regulated learning of learners with respect to their subject (science and non…

  19. High luminosity operation of large solid angle scintillator arrays in Jefferson Lab Hall A

    SciTech Connect

    Ran Shneor

    2003-12-01

    This thesis describes selected aspects of high luminosity operation of large solid angle scintillator arrays in Hall A of the CEBAF (Central Electron Beam Accelerator Facility) at TJNAF (Thomas Jefferson National Accelerator Facility ). CEBAF is a high current, high duty factor electron accelerator with a maximum beam energy of about 6 GeV and a maximum current of 200 {micro}A. Operating large solid angle scintillator arrays in high luminosity environment presents several problems such as high singles rates, low signal to noise ratios and shielding requirements. To demonstrate the need for large solid angle and momentum acceptance detectors as a third arm in Hall A, we will give a brief overview of the physics motivating five approved experiments, which utilize scintillator arrays. We will then focus on the design and assembly of these scintillator arrays, with special focus on the two new detector packages built for the Short Range Correlation experiment E01-015. This thesis also contains the description and results of different tests and calibrations which where conducted for these arrays. We also present the description of a number of tests which were done in order to estimate the singles rates, data reconstruction, filtering techniques and shielding required for these counters.

  20. Detector Developments for the High Luminosity LHC Era (2/4)

    ScienceCinema

    None

    2016-07-12

    Calorimetry and Muon Spectromers - Part II: When upgrading the LHC to higher luminosities, the detector and trigger performance shall be preserved - if not improved - with respect to the nominal performance. The ongoing R&D; for new radiation tolerant front-end electronics for calorimeters with higher read-out bandwidth are summarized and new possibilities for the trigger systems are presented. Similar developments are foreseen for the muon spectrometers, where also radiation tolerance of the muon detectors and functioning at high background rates is important. The corresponding plans and research work for the calorimeter and muon detectors at a LHC with highest luminsity are presented.

  1. High Energy Neutrinos and Cosmic-Rays From Low-Luminosity Gamma-Ray Bursts?

    SciTech Connect

    Murase, Kohta; Ioka, Kunihito; Nagataki, Shigehiro; Nakamura, Takashi; /Kyoto U.

    2006-07-10

    The recently discovered gamma-ray burst (GRB) 060218/SN 2006aj is classified as an X-ray Flash with very long duration driven possibly by a neutron star. Since GRB 060218 is very near {approx} 140 Mpc and very dim, one-year observation by Swift suggests that the true rate of GRB 060218-like events might be very high so that such low luminosity GRBs (LL-GRBs) might form a different population of GRBs from the cosmological high luminosity GRBs (HL-GRBs). We found that the high energy neutrino background from such LL-GRBs could be comparable with or larger than that from HL-GRBs. If each neutrino event is detected by IceCube, later optical-infrared follow-up observations such as by Subaru could identify a Type Ibc supernova associated with LL-GRBs, even if gamma- and X-rays are not observed by Swift. This is in a sense a new window from neutrino astronomy, which might enable us to confirm the existence of LL-GRBs and to obtain information about their rate and origin. We also argue LL-GRBs as high energy gamma-ray and cosmic-ray sources.

  2. XMM-Newton observations of high-luminosity radio-quiet quasi-stellar objects

    NASA Astrophysics Data System (ADS)

    Page, K. L.; Reeves, J. N.; O'Brien, P. T.; Turner, M. J. L.; Worrall, D. M.

    2004-09-01

    XMM-Newton observations of five high-luminosity radio-quiet quasi-stellar objects (QSOs; Q 0144-3938, UM 269, PG 1634+706, SBS 0909+532 and PG 1247+267) are presented. Spectral energy distributions were calculated from the XMM-Newton European Photon Imaging Camera (EPIC) and Optical Monitor (OM) data, with bolometric luminosities estimated in the range from 7 × 1045 to 2 × 1048 erg s-1 for the sample, peaking in the ultraviolet. At least four of the QSOs show a similar soft excess, which can be well modelled by either one or two blackbody components, in addition to the hard X-ray power law. The temperatures of these blackbodies (~100-500 eV) are too high to be direct thermal emission from the accretion disc, so Comptonization is suggested. Two populations of Comptonizing electrons, with different temperatures, are needed to model the broad-band spectrum. The hotter of these produces what is seen as the hard X-ray power law, while the cooler (~0.25-0.5 keV) population models the spectral curvature at low energies. Only one of the QSOs shows evidence for an absorption component, while three of the five show neutral iron emission. Of these, PG 1247+267 seems to have a broad line (with an equivalent width of ~250 eV), with a strong, associated reflection component (R~ 2), measured out to 30 keV in the rest frame of the QSO. Finally, it is concluded that the X-ray continuum shape of active galactic nuclei remains essentially constant over a wide range of black hole mass and luminosity.

  3. Development of Edgeless Silicon Pixel Sensors on p-type substrate for the ATLAS High-Luminosity Upgrade

    NASA Astrophysics Data System (ADS)

    Calderini, G.; Bagolini, A.; Beccherle, R.; Bomben, M.; Boscardin, M.; Bosisio, L.; Chauveau, J.; Giacomini, G.; La Rosa, A.; Marchiori, G.; Zorzi, N.

    2016-09-01

    In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate to achieve a large area instrumented with pixel sensors, since it is radiation hard and cost effective. The presentation describes the performance of novel n-in-p edgeless planar pixel sensors produced by FBK-CMM, making use of the active trench for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, some feedback from preliminary results of the first beam test will be discussed.

  4. Matching into the Helical Bunch Coalescing Channel for a High Luminosity Muon Collider

    SciTech Connect

    Sy, Amy; Ankenbrandt, Charles; Derbenev, Yaroslav; Morozov, Vasiliy; Neuffer, David; Yonehara, Katsuya; Yoshikawa, Cary; Johnson, R. P.

    2015-09-01

    For high luminosity in a muon collider, muon bunches that have been cooled in the six-dimensional helical cooling channel (HCC) must be merged into a single bunch and further cooled in preparation for acceleration and transport to the collider ring. The helical bunch coalescing channel has been previously simulated and provides the most natural match from helical upstream and downstream subsystems. This work focuses on the matching from the exit of the multiple bunch HCC into the start of the helical bunch coalescing channel. The simulated helical matching section simultaneously matches the helical spatial period lambda in addition to providing the necessary acceleration for efficient bunch coalescing. Previous studies assumed that the acceleration of muon bunches from p=209.15 MeV/c to 286.816 MeV/c and matching of lambda from 0.5 m to 1.0 m could be accomplished with zero particle losses and zero emittance growth in the individual bunches. This study demonstrates nonzero values for both particle loss and emittance growth, and provides considerations for reducing these adverse effects to best preserve high luminosity.

  5. Prototyping of an HV-CMOS demonstrator for the High Luminosity-LHC upgrade

    NASA Astrophysics Data System (ADS)

    Vilella, E.; Benoit, M.; Casanova, R.; Casse, G.; Ferrere, D.; Iacobucci, G.; Peric, I.; Vossebeld, J.

    2016-01-01

    HV-CMOS sensors can offer important advantages in terms of material budget, granularity and cost for large area tracking systems in high energy physics experiments. This article presents the design and simulated results of an HV-CMOS pixel demonstrator for the High Luminosity-LHC. The pixel demonstrator has been designed in the 0.35 μm HV-CMOS process from ams AG and submitted for fabrication through an engineering run. To improve the response of the sensor, different wafers with moderate to high substrate resistivities are used to fabricate the design. The prototype consists of four large analog and standalone matrices with several pixel flavours, which are all compatible for readout with the FE-I4 ASIC. Details about the matrices and the pixel flavours are provided in this article.

  6. An Deficiency of High Redshift, High Luminosity X-ray Clusters: Evidence for a High Value for Omega.

    NASA Astrophysics Data System (ADS)

    Nichol, R. C.; Reichart, D.; Romer, A. Kathy; Collins, C. A.; Burke, D. J.; Holden, B. P.; Ulmer, M. P.

    1997-12-01

    There have been several recent analyses of clusters taken from the EMSS sample (Henry et al 1997) that have yielded yield low values (Omega_0<0.3) for the cosmic density (Donahue et al 1997, Carlberg et al 1997). By contrast, the results from a new analysis - which takes full account of the evolution in the luminosity temperature relationship - supports values of Omega_0 close to unity. We present our method and its application to two flux limited samples of high redshift clusters; the revised EMSS sample from Nichol et al (1997) and the SHARC South sample of Burke et al (1997). We go on to discuss possible systematic errors in our method and in the two cluster samples that might be mimicing a high value of Omega.

  7. Soft X-ray spectral observations of quasars and high X-ray luminosity Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Petre, R.; Mushotzky, R. F.; Krolik, J. H.; Holt, S. S.

    1983-01-01

    Results of the analysis of 28 Einstein SSS observations of 15 high X-ray luminosity (L(x) 10 to the 435 power erg/s) quasars and Seyfert type 1 nuclei are presented. The 0.75-4.5 keV spectra are in general well fit by a simple model consisting of a power law plus absorption by cold gas. The averager spectral index alpha is 0.66 + or - .36, consistent with alpha for the spectrum of these objects above 2 keV. In all but one case, no evidence was found for intrinsic absorption, with an upper limit of 2 x 10 to the 21st power/sq cm. Neither was evidence found for partial covering of the active nucleus by dense, cold matter (N(H) 10 to the 22nd power/sq cm; the average upper limit on the partial covering fraction is 0.5. There is no obvious correlation between spectral index and 0175-4.5 keV X-ray luminosity (which ranges from 3 x 10 to the 43rd to 47th powers erg/s or with other source properties. The lack of intrinsic X-ray absorption allows us to place constraints on the density and temperature of the broad-line emission region, and narrow line emission region, and the intergalactic medium.

  8. Analysis of the BRAN Forward High Luminosity Detectors at the LHC

    NASA Astrophysics Data System (ADS)

    Green, Brett; Ratti, Alessandro; Matis, Howard

    2013-10-01

    The Beam Rate of Neutrals detectors measure relative luminosity in the far forward regions of ATLAS and CMS at the LHC by detecting secondary showers from neutral particles using high-pressure ionization chambers. One detector is on each side, clockwise and counterclockwise, of ATLAS and CMS. Proton-proton, proton-lead, and lead-lead collisions have been measured. We have simulated the detector during all three collision types (pp, pPb, and PbPb) in the modeling program FLUKA. The detectors take measurements in both pulse height and counting modes for four separate quadrants. Pulse height mode measures changes in voltage caused by incoming particles, whereas counting mode measures the number of times a threshold was exceeded. We show that the detector can measure luminosity for all reaction types on both sides, a range extending over three orders of magnitude. We calculate crossing angle, and we quantify reaction asymmetry. We show that by comparing data with known and accepted values we may calibrate the detector. This research was supported by the Department of Energy's Workforce Development of Teachers and Scientists, Berkeley Lab, and Berkeley Lab's Center for Science and Engineering Education.

  9. Changes to the Transfer Line Collimation System for the High-Luminosity LHC Beams

    SciTech Connect

    Kain, V.; Aberle, O.; Bracco, C.; Fraser, M.; Galleazzi, F.; Gianfelice-Wendt, E.; Kosmicki, A.; Maciariello, F.; Meddahi, M.; Nuiry, F. X.; Steele, G.; Velotti, F.

    2015-06-01

    The current LHC transfer line collimation system will not be able to provide enough protection for the high brightness beams in the high-luminosity LHC era. The new collimation system will have to attenuate more and be more robust than its predecessor. The active jaw length of the new transfer line collimators will therefore be 2.1 m instead of currently 1.2 m. The transfer line optics will have to be adjusted for the new collimator locations and larger beta functions at the collimators for absorber robustness reasons. In this paper the new design of the transfer line collimation system will be presented with its implications on transfer line optics and powering, maintainability, protection of transfer line magnets in case of beam loss on a collimator and protection of the LHC aperture.

  10. A high-redshift IRAS galaxy with huge luminosity - Hidden quasar or protogalaxy?

    NASA Technical Reports Server (NTRS)

    Rowan-Robinson, M.; Broadhurst, T.; Oliver, S. J.; Taylor, A. N.; Lawrence, A.; Mcmahon, R. G.; Lonsdale, C. J.; Hacking, P. B.; Conrow, T.

    1991-01-01

    An emission line galaxy with the enormous far-IR luminosity of 3 x 10 to the 14th solar has been found at z = 2.286. The spectrum is very unusual, showing lines of high excitation but with very weak Lyman-alpha emission. A self-absorbed synchrotron model for the IR energy distribution cannot be ruled out, but a thermal origin seems more plausible. A radio-quiet quasar embedded in a very dusty galaxy could account for the IR emission, as might a starburst embedded in 1-10 billion solar masses of dust. The latter case demands so much dust that the object would probably be a massive galaxy in the process of formation. The presence of a large amount of dust in an object of such high redshift implies the generation of heavy elements at an early cosmological epoch.

  11. Exploring the Standard Model with the High Luminosity, Polarized Electron-Ion Collider

    SciTech Connect

    Milner, Richard G.

    2009-08-04

    The Standard Model is only a few decades old and has been successfully confirmed by experiment, particularly at the high energy frontier. This will continue with renewed vigor at the LHC. However, many important elements of the Standard Model remain poorly understood. In particular, the exploration of the strong interaction theory Quantum Chromodynamics is in its infancy. How does the spin-1/2 of the proton arise from the fundamental quark and gluon constituents? Can we understand the new QCD world of virtual quarks and gluons in the nucleon? Using precision measurements can we test the limits of the Standard Model and look for new physics? To address these and other important questions, physicists have developed a concept for a new type of accelerator, namely a high luminosity, polarized electron-ion collider. Here the scientific motivation is summarized and the accelerator concepts are outlined.

  12. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Quittnat, Milena; CMS Collaboration

    2015-02-01

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measured signal.

  13. Research and development for a free-running readout system for the ATLAS LAr Calorimeters at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Hils, Maximilian

    2016-07-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the Large Hadron Collider (LHC) at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2 s-1. The High Luminosity LHC (HL-LHC) programme is now developed for up to 5-7 times the design luminosity, with the goal of accumulating an integrated luminosity of 3000 fb-1. In the HL-LHC phase, the increased radiation levels and an improved ATLAS trigger system require a replacement of the Front-end (FE) and Back-end (BE) electronics of the LAr Calorimeters. Results from research and development of individual components and their radiation qualification as well as the overall system design will be presented.

  14. High Stakes Testing and Student Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    The effects of high stakes testing may be critical in the lives of public school students and may have many consequences for schools and teachers. There are no easy answers in measuring student achievement and in holding teachers accountable for learner progress. High stakes testing also involves responsibilities on the part of the principal who…

  15. Student Perceptions of High-Achieving Classmates

    ERIC Educational Resources Information Center

    Händel, Marion; Vialle, Wilma; Ziegler, Albert

    2013-01-01

    The reported study investigated students' perceptions of their high-performing classmates in terms of intelligence, social skills, and conscientiousness in different school subjects. The school subjects for study were examined with regard to cognitive, physical, and gender-specific issues. The results show that high academic achievements in…

  16. Upgraded Readout Electronics for the ATLAS Liquid Argon Calorimeters at the High Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Andeen, Timothy R.; ATLAS Liquid Argon Calorimeter Group

    2012-12-01

    The ATLAS liquid-argon calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sum analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up background expected during the high luminosity phases of the LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons or photons, at high background rejection rates. For the first upgrade phase in 2018, new Liquid Argon Trigger Digitizer Boards are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new, off-detector digital processing system. The digital processing system applies digital filtering and identifies significant energy depositions. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. The general concept of the upgraded liquid-argon calorimeter readout together with the various electronics components to be developed for such a complex system is presented. The research activities and architectural studies undertaken by the ATLAS Liquid Argon Calorimeter Group are described, particularly details of the on-going design of mixed-signal front-end electronics, of radiation tolerant optical-links, and of the high-speed off-detector digital processing system.

  17. Radiation damage considerations in a high luminosity collider: The interaction region

    SciTech Connect

    Lee, D.M.

    1992-01-01

    The interaction region in a high luminosity collider will be a source of radiation for all components in the vicinity and will place stringent requirements on their design. The major components in the vicinity and will place stingent requirements on their design. The major components in the vicinity of the interaction region are the physics detectors that surround the beam pipe and the focusing quadrupole magnets nearby. We will present the radiation levels in such a physics detector and the power in the forward direction that will be deposited in the forward calorimeters and quad magnets. The implications of the levels on a variety of detector components and electronics will be presented. The calculational techniques and limitation will be reviewed.

  18. Development of radiation hard semiconductor sensors for charged particle tracking at very high luminosities

    NASA Astrophysics Data System (ADS)

    Betancourt, Christopher; Fadeyev, Vitaliy; Sadrozinski, Hartmut F.; Wright, John

    2010-09-01

    The RD50 collaboration (sponsored by the European Organization for Nuclear Research CERN) has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1 MeV neutron equivalent (neq) cm-2. This is much larger than typical fluences in space, but is mainly limited to displacement and total dose damage, without the single-event effects typical for the space environment. RD50 investigates radiation hardening from many angles, including: Search for alternative semiconductor to replace silicon, improvement of the intrinsic tolerance of the substrate material (p- vs. n-type, initial doping concentration, oxygen concentration), optimization of the readout geometry (collection of holes or electrons, surface treatment), novel detector designs (3D, edge-less, interconnects).

  19. High Achievers: 23rd Annual Survey. Attitudes and Opinions from the Nation's High Achieving Teens.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Northbrook, IL.

    This report presents data from an annual survey of high school student leaders and high achievers. It is noted that of the nearly 700,000 high achievers featured in this edition, 5,000 students were sent the survey and 2,092 questionnaires were completed. Subjects were high school juniors and seniors selected for recognition by their principals or…

  20. High-Redshift QSOs in the SWIRE Survey and the z~3 QSO Luminosity Function

    NASA Astrophysics Data System (ADS)

    Siana, Brian; Polletta, Maria del Carmen; Smith, Harding E.; Lonsdale, Carol J.; Gonzalez-Solares, Eduardo; Farrah, Duncan; Babbedge, Tom S. R.; Rowan-Robinson, Michael; Surace, Jason; Shupe, David; Fang, Fan; Franceschini, Alberto; Oliver, Seb

    2008-03-01

    We use a simple optical/infrared (IR) photometric selection of high-redshift QSOs that identifies a Lyman break in the optical photometry and requires a red IR color to distinguish QSOs from common interlopers. The search yields 100 z ~ 3 (U-dropout) QSO candidates with 19 < r' < 22 over 11.7 deg2 in the ELAIS-N1 (EN1) and ELAIS-N2 (EN2) fields of the Spitzer Wide-area Infrared Extragalactic (SWIRE) Legacy Survey. The z ~ 3 selection is reliable, with spectroscopic follow-up of 10 candidates confirming that they are all QSOs at 2.83 < z < 3.44. We find that our z ~ 4 (g'-dropout) sample suffers from both unreliability and incompleteness but present seven previously unidentified QSOs at 3.50 < z < 3.89. Detailed simulations show our z ~ 3 completeness to be ~80%-90% from 3.0 < z < 3.5, significantly better than the ~30%-80% completeness of the SDSS at these redshifts. The resulting luminosity function extends 2 mag fainter than SDSS and has a faint-end slope of β = - 1.42 +/- 0.15, consistent with values measured at lower redshift. Therefore, we see no evidence for evolution of the faint-end slope of the QSO luminosity function. Including the SDSS QSO sample, we have now directly measured the space density of QSOs responsible for ~70% of the QSO UV luminosity density at z ~ 3. We derive a maximum rate of H I photoionization from QSOs at z ~ 3.2, Γ = 4.8 × 10-13 s-1, about half of the total rate inferred through studies of the Lyα forest. Therefore, star-forming galaxies and QSOs must contribute comparably to the photoionization of H I in the intergalactic medium at z ~ 3. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  1. Metallicity and far-infrared luminosity of high-redshift quasars

    NASA Astrophysics Data System (ADS)

    Simon, Leah E.; Hamann, Fred

    2010-09-01

    We present the results of an exploratory study of broad-line region (BLR) metallicity in 34 2.2 <= z <= 4.6 quasars with far-infrared (FIR) luminosities (LFIR) from 1013.4 to <=1012.1 Lsolar. Quasar samples sorted by LFIR might represent an evolutionary sequence if the star formation rates (SFRs) in quasar hosts generally diminish across quasar lifetimes. We use rest-frame ultraviolet spectra from the Sloan Digital Sky Survey to construct three composite spectra sorted by LFIR, corresponding to average SFRs of 4980, 2130 and <=340 Msolar yr-1 after correcting for a nominal quasar FIR contribution. The measured NV λ1240/CIV λ1550 and SiIV λ1397+OIV] λ1402/CIV λ1550 emission line ratios indicate supersolar BLR metallicities in all three composites, with no evidence for a trend with the star formation rate. The formal derived metallicities, Z ~ 5-9Zsolar, are similar to those derived for the BLRs of other quasars at similar redshifts and luminosities. These results suggest that the ongoing star formation in the host is not responsible for the metal enrichment of the BLR gas. Instead, the BLR gas must have been enriched before the visible quasar phase. These results for high quasar metallicities, regardless of LFIR, are consistent with evolution scenarios wherein visibly bright quasars appear after the main episode(s) of star formation and metal enrichment in the host galaxies. Finally, young quasars, those more closely associated with a recent merger or a blowout of gas and dust, may exhibit tracers of these events, such as redder continuum slopes and higher incidence of narrow absorption lines. With the caveat of small sample sizes, we find no relation between LFIR and the reddening or the incidence of absorption lines.

  2. Achieving High Performance Perovskite Solar Cells

    NASA Astrophysics Data System (ADS)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  3. Reliability achievement in high technology space systems

    NASA Technical Reports Server (NTRS)

    Lindstrom, D. L.

    1981-01-01

    The production of failure-free hardware is discussed. The elements required to achieve such hardware are: technical expertise to design, analyze, and fully understand the design; use of high reliability parts and materials control in the manufacturing process; and testing to understand the system and weed out defects. The durability of the Hughes family of satellites is highlighted.

  4. Luminosity monitor.

    SciTech Connect

    Underwood, D. G.

    1998-07-16

    Luminosity monitors are needed in each experiment doing spin physics at RHIC. They concentrate on the luminosity aspects here because, for example, with a 10{sup {minus}3} raw asymmetry in an experiment, an error of 10{sup {minus}4} in the luminosity is as significant as a 10% polarization error. Because luminosity is a property of how two beams overlap, the luminosity at an interaction region must be measured at that interaction region in order to be relevant to the experiment at that interaction region. The authors will have to do the physics and the luminosity measurements by using labels on the event sums according to the polarization labels on the colliding bunches. Most likely they will not have independent polarization measurement on each bunch, but only on all the filled bunches in a ring, or perhaps all the bunches that are actually used in an experiment. Most analyses can then be handled by using the nine combinations gotten from three kinds of bunches in each ring, +, {minus} and empty bunches. The empty bunches are needed to measure beam-gas background, (and some, like six in a row, are needed for the beam abort). Much of the difficulty comes from the fact that they must use a physics process to represent the luminosity. This process must have kinematic and geometric cuts both to reduce systematics such as beam-gas backgrounds, and to make it representative of the part of the interaction diamond from which the physics events come.

  5. Early predictors of high school mathematics achievement.

    PubMed

    Siegler, Robert S; Duncan, Greg J; Davis-Kean, Pamela E; Duckworth, Kathryn; Claessens, Amy; Engel, Mimi; Susperreguy, Maria Ines; Chen, Meichu

    2012-07-01

    Identifying the types of mathematics content knowledge that are most predictive of students' long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students' knowledge of algebra and overall mathematics achievement. Analyses of large, nationally representative, longitudinal data sets from the United States and the United Kingdom revealed that elementary school students' knowledge of fractions and of division uniquely predicts those students' knowledge of algebra and overall mathematics achievement in high school, 5 or 6 years later, even after statistically controlling for other types of mathematical knowledge, general intellectual ability, working memory, and family income and education. Implications of these findings for understanding and improving mathematics learning are discussed.

  6. VLT/FORS2 observations of four high-luminosity ULX candidates

    NASA Astrophysics Data System (ADS)

    Heida, M.; Jonker, P. G.; Torres, M. A. P.; Roberts, T. P.; Miniutti, G.; Fabian, A. C.; Ratti, E. M.

    2013-07-01

    We obtained Very Large Telescope/FOcal Reducer and low dispersion Spectrograph spectra of the optical counterparts of four high-luminosity (LX ≥ 1040 erg s-1) Ultraluminous X-ray sources (ULX) candidates from the catalogue of Walton et al. We first determined accurate positions for the X-ray sources from archival Chandra observations and identified counterparts in archival optical observations that are sufficiently bright for spectroscopy with an 8 m telescope. From the spectra we determine the redshifts to the optical counterparts and emission line ratios. One of the candidate ULXs, in the spiral galaxy ESO 306-003, appears to be a bona fide ULX in an H II region. The other three sources, near the elliptical galaxies NGC 533 and NGC 741 and in the ring galaxy AM 0644-741, turn out to be background active galactic nuclei (AGN) with redshifts of 1.85, 0.88 or 1.75 and 1.40, respectively. Our findings confirm the trend of a high probability of finding background AGN for systems with a ratio of log(FX/Fopt) in the range of -1-1.

  7. Design Study of the High Luminosity LHC Recombination Dipole (D2)

    SciTech Connect

    Sabbi, GianLuca; Wang, Xiaorong

    2014-05-26

    The interaction region design of the high-luminosity LHC requires replacing the recombination dipole magnets (D2) with new ones. The preliminary specifications include an aperture of 105 mm, with 186 mm separation between the twin-aperture axes, and an operating field in the range of 3.5 to 4.5 T. The main design challenge is to decouple the magnetic field in the two apertures and ensure good field quality. The approach adopted for the present D2 magnets, using the iron yoke as a shield between the two apertures, leads to large saturation effects. In this study, we propose an alternative approach where the iron yoke is designed primarily for low saturation, and the resulting large but current-independent cross-talk between the apertures is corrected with an asymmetric arrangement of the conductor blocks. A preliminary solution based on the LHC dipole cable is presented, and the expected harmonics for geometric, saturation and persistent current effects are provided. Finally, the feasibility of an operating field at the high end of the range considered is discussed, to minimize the D2 magnet length and facilitate the space allocation for other components.

  8. Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice

    SciTech Connect

    Nosochkov, Yuri; Cai, Y.; Jiao, Y.; Wang, M-H.; Fartoukh, S.; Giovannozzi, M.; Maria, R.de; McIntosh, E.

    2012-06-25

    It has been proposed to implement the so-called Achromatic Telescopic Squeezing (ATS) scheme in the LHC high luminosity (HL) lattice to reduce beta functions at the Interaction Points (IP) up to a factor of 8. As a result, the nominal 4.5 km peak beta functions reached in the Inner Triplets (IT) at collision will be increased by the same factor. This, therefore, justifies the installation of new, larger aperture, superconducting IT quadrupoles. The higher beta functions will enhance the effects of the triplet quadrupole field errors leading to smaller beam dynamic aperture (DA). To maintain the acceptable DA, the effects of the triplet field errors must be re-evaluated, thus specifying new tolerances. Such a study has been performed for the so-called '4444' collision option of the HL-LHC layout version SLHCV3.01, where the IP beta functions are reduced by a factor of 4 in both planes with respect to a pre-squeezed value of 60 cm at two collision points. The dynamic aperture calculations were performed using SixTrack. The impact on the triplet field quality is presented.

  9. A new high-gradient correction quadrupole for the Fermilab luminosity upgrade

    SciTech Connect

    Mantsch, P.; Carson, J.; Riddiford, A.; Lamm, M.J.

    1989-03-01

    Special superconducting correction quadrupoles are needed for the luminosity upgrade of the Fermilab Tevatron Collider. These correctors are part of the low-beta system for the interaction regions at B/phi/ and D/phi/. The requirements are high gradient and low current. A quadrupole has been designed that meets the operating gradient of 0.63 T/cm at 1086 A. The one-layer quadrupole is wound with a cable consisting of five individually insulated rectangular strands. The five strands are overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford style cable. Once the magnet is complete the five strands are connected in series. A prototype quadrupole has been assembled and tested. The magnet reached a plateau current of 1560 A corresponding to a gradient of 0.91 T/cm without training. The measured field harmonics are substantially better than required. 8 refs., 6 figs., 4 tabs.

  10. MAD Adaptive Optics Imaging of High-luminosity Quasars: A Pilot Project

    NASA Astrophysics Data System (ADS)

    Liuzzo, E.; Falomo, R.; Paiano, S.; Treves, A.; Uslenghi, M.; Arcidiacono, C.; Baruffolo, A.; Diolaiti, E.; Farinato, J.; Lombini, M.; Moretti, A.; Ragazzoni, R.; Brast, R.; Donaldson, R.; Kolb, J.; Marchetti, E.; Tordo, S.

    2016-08-01

    We present near-IR images of five luminous quasars at z ˜ 2 and one at z ˜ 4 obtained with an experimental adaptive optics (AO) instrument at the European Southern Observatory Very Large Telescope. The observations are part of a program aimed at demonstrating the capabilities of multi-conjugated adaptive optics imaging combined with the use of natural guide stars for high spatial resolution studies on large telescopes. The observations were mostly obtained under poor seeing conditions but in two cases. In spite of these nonoptimal conditions, the resulting images of point sources have cores of FWHM ˜ 0.2 arcsec. We are able to characterize the host galaxy properties for two sources and set stringent upper limits to the galaxy luminosity for the others. We also report on the expected capabilities for investigating the host galaxies of distant quasars with AO systems coupled with future Extremely Large Telescopes. Detailed simulations show that it will be possible to characterize compact (2-3 kpc) quasar host galaxies for quasi-stellar objects at z = 2 with nucleus K-magnitude spanning from 15 to 20 (corresponding to absolute magnitude -31 to -26) and host galaxies that are 4 mag fainter than their nuclei.

  11. Dark-ages reionization and galaxy formation simulation - IV. UV luminosity functions of high-redshift galaxies

    NASA Astrophysics Data System (ADS)

    Liu, Chuanwu; Mutch, Simon J.; Angel, P. W.; Duffy, Alan R.; Geil, Paul M.; Poole, Gregory B.; Mesinger, Andrei; Wyithe, J. Stuart B.

    2016-10-01

    In this paper, we present calculations of the UV luminosity function (LF) from the Dark-ages Reionization And Galaxy-formation Observables from Numerical Simulations project, which combines N-body, semi-analytic and seminumerical modelling designed to study galaxy formation during the Epoch of Reionization. Using galaxy formation physics including supernova feedback, the model naturally reproduces the UV LFs for high-redshift star-forming galaxies from z ˜ 5 through to z ˜ 10. We investigate the luminosity-star formation rate (SFR) relation, finding that variable SFR histories of galaxies result in a scatter around the median relation of 0.1-0.3 dex depending on UV luminosity. We find close agreement between the model and observationally derived SFR functions. We use our calculated luminosities to investigate the LF below current detection limits, and the ionizing photon budget for reionization. We predict that the slope of the UV LF remains steep below current detection limits and becomes flat at MUV ≳ -14. We find that 48 (17) per cent of the total UV flux at z ˜ 6 (10) has been detected above an observational limit of MUV ˜ -17, and that galaxies fainter than MUV ˜ -17 are the main source of ionizing photons for reionization. We investigate the luminosity-stellar mass relation, and find a correlation for galaxies with MUV < -14 that has the form M_{ast } ∝ 10^{-0.47M_UV}, in good agreement with observations, but which flattens for fainter galaxies. We determine the luminosity-halo mass relation to be M_vir ∝ 10^{-0.35M_UV}, finding that galaxies with MUV = -20 reside in host dark matter haloes of 1011.0±0.1 M⊙ at z ˜ 6, and that this mass decreases towards high redshift.

  12. Attitudes and Opinions from the Nation's High Achieving Teens. 18th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Educational Communications, Inc., Lake Forest, IL.

    This document contains factsheets and news releases which cite findings from a national survey of 1,985 high achieving high school students. Factsheets describe the Who's Who Among American High School Students recognition and service program for high school students and explain the Who's Who survey. A summary report of this eighteenth annual…

  13. Aperture synthesis mapping of molecular gas in high-luminosity IRAS galaxies

    NASA Technical Reports Server (NTRS)

    Sanders, D. B.; Soifer, B. T.; Scoville, N. Z.; Sargent, A. I.

    1988-01-01

    The Owens Valley millimeter-wave interferometer has been used for high-resolution mapping of the 2.6 mm CO emission from the high-luminosity infrared galaxies NGC 520 (Arp 157), NGC 7469 (Arp 298), and Arp 55. Assuming the same empirical relationship between CO brightness and molecular hydrogen surface mass density as has been found for giant molecular clouds in the Milky Way, it is found that the masses of H2 gas in these concentrations are 10 to the 9th - 10 to the 10th solar masses, typically one-third of the total molecular gas content of these galaxies. The interferometric sizes correspond to radii of 0.8 kpc (NGC 520), 1.4 kpc (NGC 7469), and less than 2.8 kpc (Arp 55). For the same regions the dynamical masses estimated from the CO line width and size of the emission region are only a factor of 3-5 higher. The mean molecular gas surface densities averaged over these regions are in the range 610-825 solar masses/sq pc, a factor of 10 brighter than those obtained for corresponding regions in the nucleus of the Milky Way. The high mass fractions obtained for the interstellar medium in the central regions of these three galaxies strongly suggest that large-scale gravitational instability in the gas may play an important role in the further concentration of the gas in the nucleus and in possibly precipitating a large-scale burst of star formation.

  14. A Compton-thick Wind in the High Luminosity Quasar, PDS 456

    NASA Technical Reports Server (NTRS)

    Reeves, J. N.; O'Brien, P. T.; Behar, E.; Miller, L.; Turner, T. J.; Braito, V.; Fabian, A. C.; Kaspi, S.; Mushotzky, R.; Ward, M.

    2009-01-01

    PDS 456 is a nearby (z=0.184), luminous (L(sub bol) approximately equal to 10(exp 47) ergs(exp -1) type I quasar. A deep 190 ks Suzaku observation in February 2007 revealed the complex, broad band X-ray spectrum of PDS 456. The Suzaku spectrum exhibits highly statistically significant absorption features near 9 keV in the quasar rest-frame. We show that the most plausible origin of the absorption is from blue-shifted resonance (1s-2p) transitions of hydrogen-like iron (at 6.97 keV in the rest frame). This indicates that a highly ionized outflow may be present moving at near relativistic velocities (0.26-0.31c). A possible hard X-ray excess is detected above 15 keV with HXD (at 99.8% confidence), which may arise from high column density gas (N(sub H) greater than 10(exp 24)cm(exp -2) partially covering the X-ray emission, or through strong Compton reflection. Here we propose that the iron K-shell absorption in PDS 456 is associated with a thick, possibly clumpy outflow, covering about 20% of 4(pi) steradian solid angle. The outflow is likely launched from the inner accretion disk, within 15-100 gravitational radii of the black hole. The kinetic power of the outflow may be similar to the bolometric luminosity of PDS 456. Such a powerful wind could have a significant effect on the co-evolution of the host galaxy and its supermassive black hole, through feedback.

  15. Concepts for ELIC - A High Luminosity CEBAF Based Electron-Light Ion Collider

    SciTech Connect

    Ya. Derbenev, A. Bogacz, G. Krafft, R. Li, L. Merminga, B. Yunn, Y. Zhang

    2006-09-01

    A CEBAF accelerator based electron-light ion collider (ELIC) of rest mass energy from 20 to 65 GeV and luminosity from 10^33 to 10^35 cm6-2s^-1 with both beams polarized is envisioned as a future upgrade to CEBAF. A two step upgrade scenario is under study: CEBAF accelerator-ring-ring scheme (CRR) as the first step, and a multi-turn ERL-ring as the second step, to attain a better electron emittance and maximum luminosity. In this paper we report results of our studies of the CRR version of ELIC.

  16. 21st Annual Survey of High Achievers: Attitudes and Opinions from the Nation's High Achieving Teens.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This survey was conducted by Who's Who Among American High School Students during the spring of 1990, to determine the attitudes of student leaders in U.S. high schools. A survey of high achievers sent to 5,000 students was completed and returned by approximately 2,000 students. All students were members of the junior or senior class during the…

  17. 22nd Annual Survey of High Achievers: Attitudes and Opinions from the Nation's High Achieving Teens.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Northbrook, IL.

    This study surveyed high school students (N=1,879) who were student leaders or high achievers in the spring of 1991 for the purpose of determining their attitudes. Students were members of the junior or senior high school class during the 1990-91 academic year and were selected for recognition by their principals or guidance counselors, other…

  18. The hard X-ray luminosity function of high-redshift (3 < z ≲ 5) active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Vito, F.; Gilli, R.; Vignali, C.; Comastri, A.; Brusa, M.; Cappelluti, N.; Iwasawa, K.

    2014-12-01

    We present the hard-band (2-10 keV) X-ray luminosity function (HXLF) of 0.5-2 keV band selected active galactic nuclei (AGN) at high redshift. We have assembled a sample of 141 AGN at 3 < z ≲ 5 from X-ray surveys of different size and depth, in order to sample different regions in the LX - z plane. The HXLF is fitted in the range log LX ˜ 43-45 with standard analytical evolutionary models through a maximum likelihood procedure. The evolution of the HXLF is well described by a pure density evolution, with the AGN space density declining by a factor of ˜10 from z = 3 to 5. A luminosity-dependent density evolution model, which, normally, best represents the HXLF evolution at lower redshift, is also consistent with the data, but a larger sample of low-luminosity (log LX < 44), high-redshift AGN is necessary to constrain this model. We also estimated the intrinsic fraction of AGN obscured by a column density log NH ≥ 23 to be 0.54 ± 0.05, with no strong dependence on luminosity. This fraction is higher than the value in the Local Universe, suggesting an evolution of the luminous (LX > 1044 erg s-1) obscured AGN fraction from z = 0 to z > 3.

  19. Light dark sector searches at low-energy high-luminosity e + e - colliders

    NASA Astrophysics Data System (ADS)

    Yin, Peng-Fei; Zhu, Shou-Hua

    2016-10-01

    Although the standard model (SM) is extremely successful, there are various motivations for considering the physics beyond the SM. For example, the SM includes neither dark energy nor dark matter, which has been confirmed through astrophysical observations. Examination of the dark sector, which contains new, light, weakly-coupled particles at the GeV scale or lower, is well motivated by both theory and dark-matter detection experiments. In this mini-review, we focus on one particular case in which these new particles can interact with SM particles through a kinematic mixing term between U(1) gauge bosons. The magnitude of the mixing can be parameterized by a parameter є. Following a brief overview of the relevant motivations and the constraints determined from numerous experiments, we focus on the light dark sector phenomenology at low-energy high-luminosity e + e - colliders. These colliders are ideal for probing the new light particles, because of their large production rates and capacity for precise resonance reconstruction. Depending on the details of a given model, the typical observed signatures may also contain multi lepton pairs, displaced vertices, and/or missing energy. Through the use of extremely large data samples from existing experiments, such as KLOE, CLEO, BABAR, Belle, and BESIII, the magnitude of the mixing can be parameterized by a parameter є < 10-4-10-3 constraint can be obtained. Obviously, future experiments with larger datasets will provide opportunities for the discovery of new particles in the dark sector, or for stricter upper limits on є. Once the light dark sector is confirmed, the particle physics landscape will be changed significantly.

  20. Attitudes and Opinions from the Nation's High Achieving Teens: 26th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    A national survey of 3,351 high achieving high school students (junior and senior level) was conducted. All students had A or B averages. Topics covered include lifestyles, political beliefs, violence and entertainment, education, cheating, school violence, sexual violence and date rape, peer pressure, popularity, suicide, drugs and alcohol,…

  1. Attitudes and Opinions from the Nation's High Achieving Teens. 24th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This survey represents information compiled by the largest national survey of adolescent leaders and high achievers. Of the 5,000 students selected demographically from "Who's Who Among American High School Students," 1,957 responded. All students surveyed had "A" or "B" averages, and 98% planned on attending college. Questions were asked about…

  2. Final Cooling for a High-Energy High-Luminosity Lepton Collider

    SciTech Connect

    Neuffer, David; Sayed, H.; Hart, T.; Summers, D.

    2015-12-03

    A high-energy muon collider scenario require a “final cooling” system that reduces transverse emittance by a factor of ~10 while allowing longitudinal emittance increase. The baseline approach has low-energy transverse cooling within high-field solenoids, with strong longitudinal heating. This approach and its recent simulation are discussed. Alternative approaches which more explicitly include emittance exchange are also presented. Round-to-flat beam transform, transverse slicing, and longitudinal bunch coalescence are possible components of an alternative approach. Wedge-based emittance exchange could provide much of the required transverse cooling with longitudinal heating. Li-lens and quadrupole focusing systems could also provide much of the required final cooling.

  3. Run II luminosity progress

    SciTech Connect

    Gollwitzer, K.; /Fermilab

    2007-06-01

    The Fermilab Tevatron Collider Run II program continues at the energy and luminosity frontier of high energy particle physics. To the collider experiments CDF and D0, over 3 fb{sup -1} of integrated luminosity has been delivered to each. Upgrades and improvements in the Antiproton Source of the production and collection of antiprotons have led to increased number of particles stored in the Recycler. Electron cooling and associated improvements have help make a brighter antiproton beam at collisions. Tevatron improvements to handle the increased number of particles and the beam lifetimes have resulted in an increase in luminosity.

  4. Jet identification and energy scale corrections in a high-luminosity environment at the LHC

    NASA Astrophysics Data System (ADS)

    Miller, David

    2009-05-01

    The LHC physics program will ultimately probe not only the highest energies ever produced in the laboratory but also the most numerous and frequent collisions between hadronic particles ever. These luminosities will produce hadronic jets from simultaneous proton-proton collisions in unprecedented numbers, presenting extreme challenges for jet identification, calibration and missing energy (ET) measurements. We present a unified jet energy scale program designed to account for these uncorrelated soft interactions using the advanced technique of associating calorimeter jets to reconstructed primary vertices using tracks. This approach suppresses the background contributions from these ``pile-up'' interactions and allows for jet-by-jet energy scale corrections for multiple interactions. This approach is shown to be vital for coping with the unparalleled luminosity of the LHC.

  5. High luminosity operation, beam-beam effects and their compensation in Tevatron

    SciTech Connect

    Shiltsev, V.; /Fermilab

    2008-06-01

    Over the past 2 years the Tevatron peak luminosity steadily progressed and reached the level of 3.15 {center_dot} 10{sup 32} cm{sup -2} s{sup -1} which exceeds the Run II Upgrade goal. We discuss the collider performance, illustrate limitations and understanding of beam-beam effects and present experimental results of compensation of the beam-beam effects by electron lenses--a technique of great interest for the LHC.

  6. PROBING HIGH-REDSHIFT GALAXY FORMATION AT THE HIGHEST LUMINOSITIES: NEW INSIGHTS FROM DEIMOS SPECTROSCOPY

    SciTech Connect

    Lee, Kyoung-Soo; Dey, Arjun; Cooper, Michael C.; Reddy, Naveen; Jannuzi, Buell T.

    2013-07-01

    We present Keck DEIMOS spectroscopic observations of the most UV-luminous star-forming galaxies at redshifts 3.2 < z < 4.6. Our sample, selected in the Booetes field of the NOAO Deep Wide-Field Survey, contains galaxies with luminosities of L* {approx}< L{sub UV} {approx}< 7 L* and is one of the largest samples to date of the most UV-luminous galaxies at these redshifts. Our spectroscopic data confirm 41 candidates as star-forming galaxies at 3.2 < z < 4.6 and validate the relatively clean selection of the photometric candidates with a contamination rate of 11%-28%. We find that the fraction of Ly{alpha} emitting galaxies increases with decreasing UV luminosity. None of the 12 galaxies with M{sub UV} < -22 (i.e., L{sub UV} > 3 L*) exhibit strong Ly{alpha} emission. We find strong evidence of large-scale outflows, transporting the neutral/ionized gas in the interstellar medium away from the galaxy. Galaxies exhibiting both interstellar absorption and Ly{alpha} emission lines show a significant offset between the two features, with a relative velocity of 200-1150 km s{sup -1}. We find tentative evidence that this measure of the outflow velocity increases with UV luminosity and/or stellar mass. The luminosity- and mass-dependent outflow strengths suggest that the efficiency of feedback and enrichment of the surrounding medium depend on these galaxy parameters. We also stack the individual spectra to construct composite spectra of the absorption-line-only and Ly{alpha}-emitting subsets of the UV luminous galaxies at z {approx_equal} 3.7. The composite spectra are very similar to those of lower-redshift and lower-luminosity Lyman break galaxy (LBG) samples, but with some subtle differences. Analyses of the composite spectra suggest that the UV luminous LBGs at z {approx_equal} 3.7 may have a higher covering fraction of absorbing gas, and may be older (or have had more prolonged star formation histories) than their lower-redshift and lower-luminosity counterparts. In

  7. Discovery of 1-5 Hz flaring at high luminosity in SAX J1808.4-3658

    SciTech Connect

    Bult, Peter; Van der Klis, Michiel

    2014-07-10

    We report the discovery of a 1-5 Hz X-ray flaring phenomenon observed at >30 mCrab near peak luminosity in the 2008 and 2011 outbursts of the accreting millisecond X-ray pulsar SAX J1808.4-3658 in observations with the Rossi X-ray Timing Explorer. In each of the two outbursts this high luminosity flaring is seen for ∼3 continuous days and switches on and off on a timescale of 1-2 hr. The flaring can be seen directly in the light curve, where it shows sharp spikes of emission at quasi-regular separation. In the power spectrum it produces a broad noise component, which peaks at 1-5 Hz. The total 0.05-10 Hz variability has a fractional rms amplitude of 20%-45%, well in excess of the 8%-12% rms broadband noise usually seen in power spectra of SAX J1808.4-3658. We perform a detailed timing analysis of the flaring and study its relation to the 401 Hz pulsations. We find that the pulse amplitude varies proportionally with source flux through all phases of the flaring, indicating that the flaring is likely due to mass density variations created at or outside the magnetospheric boundary. We suggest that this 1-5 Hz flaring is a high mass accretion rate version of the 0.5-2 Hz flaring which is known to occur at low luminosity (<13 mCrab), late in the tail of outbursts of SAX J1808.4-3658. We propose the dead-disk instability, previously suggested as the mechanism for the 0.5-2 Hz flaring, as a likely mechanism for the high luminosity flaring reported here.

  8. Support Structure Design of the $$\\hbox{Nb}_{3}\\hbox{Sn}$$ Quadrupole for the High Luminosity LHC

    DOE PAGES

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of themore » detailed 3D numerical analysis performed in preparation for the first short model test.« less

  9. High Involvement Mothers of High Achieving Children: Potential Theoretical Explanations

    ERIC Educational Resources Information Center

    Hunsaker, Scott L.

    2013-01-01

    In American society, parents who have high aspirations for the achievements of their children are often viewed by others in a negative light. Various pejoratives such as "pushy parent," "helicopter parent," "stage mother," and "soccer mom" are used in the common vernacular to describe these parents. Multiple…

  10. SuperB: A High-Luminosity Asymmetric e+e- Super Flavor Factory

    SciTech Connect

    Bona, M.; /et al.

    2007-05-18

    We discuss herein the exciting physics program that can be accomplished with a very large sample of heavy quark and heavy lepton decays produced in the very clean environment of an e{sup +}e{sup -} collider; a program complementary to that of an experiment such as LHCb at a hadronic machine. It then presents the conceptual design of a new type of e{sup +}e{sup -} collider that produces a nearly two-order-of-magnitude increase in luminosity over the current generation of asymmetric B Factories. The key idea is the use of low emittance beams produced in an accelerator lattice derived from the ILC Damping Ring Design, together with a new collision region, again with roots in the ILC final focus design, but with important new concepts developed in this design effort. Remarkably, SuperB produces this very large improvement in luminosity with circulating currents and wallplug power similar to those of the current B Factories. There is clear synergy with ILC R&D; design efforts have already influenced one another, and many aspects of the ILC Damping Rings and Final Focus would be operationally tested at SuperB. Finally, the design of an appropriate detector, based on an upgrade of BABAR as an example, is discussed in some detail. A preliminary cost estimate is presented, as is an example construction timeline.

  11. ELIC: A High Luminosity And Efficient Spin Manipulation Electron-Light Ion Collider Based At CEBAF

    SciTech Connect

    Lia Merminga; Yaroslav Derbenev

    2004-02-01

    Electron-light ion colliders with center of mass energy between 20 and 100 GeV, luminosity between 10{sup 33} and 10{sup 35} cm{sup -2} sec{sup -1}, and polarization of both beams at or above 80% have been proposed for the study of hadronic structure. The Electron-Light Ion Collider (ELIC) facility would require the upgrade of CEBAF to 5-7 GeV energy recovering linac and the realization of an ion storage ring complex, accelerating and storing light ions of up to 150 GeV. In this report several innovative features of electron and ion beam designs and their advantages in delivering the luminosity and spin are described. These features include: electron circulator ring to reduce electron polarized source and energy recovering linac requirements, twisted spin booster and collider ring; interaction points with low beta-star and crab-crossing using the short, cooled ion bunches. Accelerator physics and technology issues for both protons/ions and electrons are presented. The feasibility of an integrated fixed target program at 25 GeV and collider program with center of mass energy between 20 and 65 GeV is explored.

  12. High Ability Readers and the Achievement Gap

    ERIC Educational Resources Information Center

    Hunsaker, Scott L.; Parke, Cynthia J.; Bramble, Joan G.

    2004-01-01

    To close the achievement gap, the "No Child Left Behind" law calls for all students to make appropriate yearly progress. This presumably means that progress is being made by capable readers at the same time progress is being made by struggling readers. However, there appear to be unintended effects of "No Child Left Behind" that may impede the…

  13. Luminosity Optimization Feedback in the SLC

    SciTech Connect

    1999-03-01

    The luminosity optimization at the SLC has been limited by the precision with which one can measure the micron size beams at the Interaction Point. Ten independent tuning parameters must be adjusted. An automated application has been used to scan each parameter over a significant range and set the minimum beam size as measured with a beam-beam deflection scan. Measurement errors limited the accuracy of this procedure and degraded the resulting luminosity. A new luminosity optimization feedback system has been developed using novel dithering techniques to maximize the luminosity with respect to the 10 parameters, which are adjusted one at a time. Control devices are perturbed around nominal setpoints, while the averaged readout of a digitized luminosity monitor measurement is accumulated for each setting. Results are averaged over many pulses to achieve high precision and then fitted to determine the optimal setting. The dithering itself causes a small loss in luminosity, but the improved optimization is expected to significantly enhance the performance of the SLC. Commissioning results are reported.

  14. High-Achieving Students in the Era of NCLB

    ERIC Educational Resources Information Center

    Loveless, Tom; Parkas, Steve; Duffett, Ann

    2008-01-01

    This report contains two separate studies examining the status of high-achieving students in the No Child Left Behind (NCLB) era. Part I, An Analysis of NAEP Data, authored by Brookings Institution scholar Tom Loveless, examines achievement trends for high-achieving students (defined, like low-achieving students, by their performance on the…

  15. A proposed Drift Tubes-seeded muon track trigger for the CMS experiment at the High Luminosity-LHC

    NASA Astrophysics Data System (ADS)

    Pozzobon, N.; Lazzizzera, I.; Vanini, S.; Zotto, P.

    2016-07-01

    The LHC program at 13 and 14 TeV, after the observation of the candidate SM Higgs boson, will help clarify future subjects of study and shape the needed tools. Any upgrade of the LHC experiments for unprecedented luminosities, such as the High Luminosity-LHC ones, must then maintain the acceptance on electroweak processes that can lead to a detailed study of the properties of the candidate Higgs boson. The acceptance of the key lepton, photon and hadron triggers should be kept such that the overall physics acceptance, in particular for low-mass scale processes, can be the same as the one the experiments featured in 2012. In such a scenario, a new approach to early trigger implementation is needed. One of the major steps will be the inclusion of high-granularity tracking sub-detectors, such as the CMS Silicon Tracker, in taking the early trigger decision. This contribution can be crucial in several tasks, including the confirmation of triggers in other subsystems, and the improvement of the on-line momentum measurement resolution. A muon track-trigger for the CMS experiment at the High Luminosity-LHC is presented. A back-extrapolation of Drift Tubes trigger primitives is proposed to match tracks found at Level 1 with muon candidates. The main figures-of-merit are presented, featuring sharp thresholds and less contamination from lower momentum muons, and an expected rate reduction of a factor of 5-10 at typical thresholds with respect to the muon trigger configuration used in 2012.

  16. X-ray View of Four High-Luminosity Swift-BAT AGN: Unveiling Obscuration and Reflection with Suzaku

    NASA Technical Reports Server (NTRS)

    Fiorettil, V.; Angelini, L.; Mushotzky, R. F.; Koss, M.; Malaguti, G.

    2013-01-01

    Aims. A complete census of obscured Active Galactic Nuclei (AGN) is necessary to reveal the history of the super massive black hole (SMBH) growth and galaxy evolution in the Universe given the complex feedback processes and the fact that much of this growth occurs in an obscured phase. In this context, hard X-ray surveys and dedicated follow-up observations represent a unique tool for selecting highly absorbed AGN and for characterizing the obscuring matter surrounding the SMBH. Here we focus on the absorption and reflection occurring in highly luminous, quasar-like AGN, to study the relation between the geometry of the absorbing matter and the AGN nature (e.g. X-ray, optical, and radio properties), and to help to determine the column density dependency on the AGN luminosity. Methods. The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray BAT fluxes in excess of 10(exp -11) erg per square centimeter and an average redshift of 0.03. Among them, four of the most luminous BAT AGN (44.73 less than LogLBAT less than 45.31) were selected as targets of Suzaku follow-up observations: J2246.0+3941 (3C 452), J0407.4+0339 (3C 105), J0318.7+6828, and J0918.5+0425. The column density, scattered/reflected emission, the properties of the Fe K line, and a possible variability are fully analyzed. For the latter, the spectral properties from Chandra, XMM-Newton and Swift/XRT public observations were compared with the present Suzaku analysis, adding an original spectral analysis when non was available from the literature. Results. Of our sample, 3C 452 is the only certain Compton-thick AGN candidate because of i) the high absorption (N(sub H) approximately 4 × 10(exp 23) per square centimeter) and strong Compton reflection; ii) the lack of variability; iii) the "buried" nature, i.e. the low scattering fraction (less than 0.5%) and the extremely low relative [OIII] luminosity. In contrast 3C 105 is not reflection-dominated, despite the comparable column density

  17. Improving Student Achievement: A Study of High-Poverty Schools with Higher Student Achievement Outcomes

    ERIC Educational Resources Information Center

    Butz, Stephen D.

    2012-01-01

    This research examined the education system at high-poverty schools that had significantly higher student achievement levels as compared to similar schools with lower student achievement levels. A multischool qualitative case study was conducted of the educational systems where there was a significant difference in the scores achieved on the…

  18. High School Employment and Youths' Academic Achievement

    ERIC Educational Resources Information Center

    Rothstein, Donna S.

    2007-01-01

    This paper asks whether employment during high school impacts youths' grade point average. Unlike much of the prior literature, it allows for the endogeneity of the hours and dropout decisions, uses ASVAB test scores, and tests whether youth employment is dynamic. The results indicate that high school employment and its lag have small, negative…

  19. RHIC PLANS TOWARDS HIGHER LUMINOSITY

    SciTech Connect

    FEDOTOV,A.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide luminosity over a wide range of beam energies and species, including heavy ions, polarized protons, and tric beam collisions. In the first seven years of operation there has been a rapid increase in the achieved peak and average luminosity, substantially exceeding design values. Work is presently underway to achieve the Enhanced Design parameters. Planned major upgrades include the Electron Beam Ion Source (EBIS), RHIC-11, and construction of an electron-ion collider (eRHIC). We review the expected RHIC upgrade performance. Electron cooling and its impact on the luminosity both for heavy ions and protons are discussed in detail.

  20. Hadronic jet-vertex association in a high-luminosity environment at the LHC

    NASA Astrophysics Data System (ADS)

    Miller, David

    2008-04-01

    The LHC physics program will ultimately probe not only the highest energies ever produced in the laboratory but also the most numerous and frequent collisions between hadronic particles ever. These particle luminosities, much above the current Tevatron values, will produce hadronic jets from simultaneous uncorrelated proton-proton collisions in unprecedented numbers, thus introducing challenges for jet identification and association with the primary collision vertices, jet energy measurements and missing energy resolution. We continue work first introduced by the Tevatron experiments to combine tracking information with calorimeter jets in order to disentangle this jet background. Using an algorithm which assigns a jet-vertex association probability, jet selection is shown to be insensitive to the contributions from these ``pile-up'' collisions, which is essential for the many physics analyses dependent on event jet multiplicity. Furthermore, jet-by-jet multiple interaction energy corrections are now possible and improvements to the primary vertex identification from jet-vertex association are gained for several interesting physics processes.

  1. Achieving strategic surety for high consequence software

    SciTech Connect

    Pollock, G.M.

    1996-09-01

    A strategic surety roadmap for high consequence software systems under the High Integrity Software (HIS) Program at Sandia National Laboratories guides research in identifying methodologies to improve software surety. Selected research tracks within this roadmap are identified and described detailing current technology and outlining advancements to be pursued over the coming decade to reach HIS goals. The tracks discussed herein focus on Correctness by Design, and System Immunology{trademark}. Specific projects are discussed with greater detail given on projects involving Correct Specification via Visualization, Synthesis, & Analysis; Visualization of Abstract Objects; and Correct Implementation of Components.

  2. Early Predictors of High School Mathematics Achievement

    ERIC Educational Resources Information Center

    Siegler, Robert S.; Duncan, Greg J.; Davis-Kean, Pamela E.; Duckworth, Kathryn; Claessens, Amy; Engel, Mimi; Susperreguy, Maria Ines; Meichu, Chen

    2012-01-01

    Identifying the types of mathematics content knowledge that are most predictive of students' long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students' knowledge of algebra and overall mathematics…

  3. Norview High School: Leadership Fosters Achievment

    ERIC Educational Resources Information Center

    Principal Leadership, 2013

    2013-01-01

    Often little unsaid things demonstrate what is truly important in a school. When teachers have common planning time and all of the department chairs share a single space as they do at Norview High School in Norfolk, VA, the unmistakable message is that instructional collaboration and leadership are expected and valued. Norview, an urban,…

  4. Achieving High-Temperature Ferromagnetic Topological Insulator

    NASA Astrophysics Data System (ADS)

    Katmis, Ferhat

    Topological insulators (TIs) are insulating materials that display conducting surface states protected by time-reversal symmetry, wherein electron spins are locked to their momentum. This unique property opens new opportunities for creating next-generation electronic and spintronic devices, including TI-based quantum computation. Introducing ferromagnetic order into a TI system without compromising its distinctive quantum coherent features could lead to a realization of several predicted novel physical phenomena. In particular, achieving robust long-range magnetic order at the TI surface at specific locations without introducing spin scattering centers could open up new possibilities for devices. Here, we demonstrate topologically enhanced interface magnetism by coupling a ferromagnetic insulator (FMI) to a TI (Bi2Se3); this interfacial ferromagnetism persists up to room temperature, even though the FMI (EuS) is known to order ferromagnetically only at low temperatures (<17 K). The induced magnetism at the interface resulting from the large spin-orbit interaction and spin-momentum locking feature of the TI surface is found to greatly enhance the magnetic ordering (Curie) temperature of the TI/FMI bilayer system. Due to the short range nature of the ferromagnetic exchange interaction, the time-reversal symmetry is broken only near the surface of a TI, while leaving its bulk states unaffected. The topological magneto-electric response originating in such an engineered TI could allow for an efficient manipulation of the magnetization dynamics by an electric field, providing an energy efficient topological control mechanism for future spin-based technologies. Work supported by MIT MRSEC through the MRSEC Program of NSF under award number DMR-0819762, NSF Grant DMR-1207469, the ONR Grant N00014-13-1-0301, and the STC Center for Integrated Quantum Materials under NSF grant DMR-1231319.

  5. On the faint-end of the high-z galaxy luminosity function

    NASA Astrophysics Data System (ADS)

    Yue, Bin; Ferrara, Andrea; Xu, Yidong

    2016-08-01

    Recent measurements of the Luminosity Function (LF) of galaxies in the Epoch of Reionization (EoR, zlower.5ex buildrel> over ˜ 6) indicate a very steep increase of the number density of low-mass galaxies populating the LF faint-end. However, as star formation in low-mass halos can be easily depressed or even quenched by ionizing radiation, a turnover is expected at some faint UV magnitudes. Using a physically-motivated analytical model, we quantify reionization feedback effects on the LF faint-end shape. We find that if reionization feedback is neglected, the power-law Schechter parameterization characterizing the LF faint-end remains valid up to absolute UV magnitude ˜-9. If instead radiative feedback is strong enough that quenches star formation in halos with circular velocity smaller than 50 km s-1, the LF starts to drop at absolute UV magnitude ˜-15, i.e. slightly below the detection limits of current (unlensed) surveys at z ˜ 5. The LFs may rise again at higher absolute UV magnitude, where, as a result of interplay between reionization process and galaxy formation, most of the galaxy light is from relic stars formed before the EoR. We suggest that the galaxy number counts data, particularly in lensed fields, can put strong constraints on reionization feedback. In models with stronger reionization feedback, stars in galaxies with absolute UV magnitude higher than ˜-13 and smaller than ˜-8 are typically older. Hence, the stellar age - UV magnitude relation can be used as an alternative feedback probe.

  6. RHIC LUMINOSITY UPGRADE PROGRAM

    SciTech Connect

    Fischer, W.

    2010-05-23

    The Relativistic Heavy Ion Collider (RHIC) operates with either ions or polarized protons. After increasing the heavy ion luminosity by two orders of magnitude since its commissioning in 2000, the current luminosity upgrade program aims for an increase by another factor of 4 by means of 3D stochastic cooling and a new 56 MHz SRF system. An Electron Beam Ion Source is being commissioned that will allow the use of uranium beams. Electron cooling is considered for collider operation below the current injection energy. For the polarized proton operation both luminosity and polarization are important. In addition to ongoing improvements in the AGS injector, the construction of a new high-intensity polarized source has started. In RHIC a number of upgrades are under way to increase the intensity and polarization transmission to 250 GeV beam energy. Electron lenses will be installed to partially compensate the head-on beam-beam effect.

  7. Self-Concept and Achievement Motivation of High School Students

    ERIC Educational Resources Information Center

    Lawrence, A. S. Arul; Vimala, A.

    2013-01-01

    The present study "Self-concept and Achievement Motivation of High School Students" was investigated to find the relationship between Self-concept and Achievement Motivation of High School Students. Data for the study were collected using Self-concept Questionnaire developed by Raj Kumar Saraswath (1984) and Achievement Motive Test (ACMT)…

  8. Conceptual Design of the Cryogenic System for the High-luminosity Upgrade of the Large Hadron Collider (LHC)

    NASA Astrophysics Data System (ADS)

    Brodzinski, K.; Claudet, S.; Ferlin, G.; Tavian, L.; Wagner, U.; Van Weelderen, R.

    The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This paper will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

  9. High-luminosity primary vertex selection in top-quark studies using the Collider Detector at Fermilab

    SciTech Connect

    Buzatu, Adrian; /McGill U.

    2006-08-01

    Improving our ability to identify the top quark pair (t{bar t}) primary vertex (PV) on an event-by-event basis is essential for many analyses in the lepton-plus-jets channel performed by the Collider Detector at Fermilab (CDF) Collaboration. We compare the algorithm currently used by CDF (A1) with another algorithm (A2) using Monte Carlo simulation at high instantaneous luminosities. We confirm that A1 is more efficient than A2 at selecting the t{bar t} PV at all PV multiplicities, both with efficiencies larger than 99%. Event selection rejects events with a distance larger than 5 cm along the proton beam between the t{bar t} PV and the charged lepton. We find flat distributions for the signal over background significance of this cut for all cut values larger than 1 cm, for all PV multiplicities and for both algorithms. We conclude that any cut value larger than 1 cm is acceptable for both algorithms under the Tevatron's expected instantaneous luminosity improvements.

  10. High luminosity, slow ejecta and persistent carbon lines: SN 2009dc challenges thermonuclear explosion scenarios

    NASA Astrophysics Data System (ADS)

    Taubenberger, S.; Benetti, S.; Childress, M.; Pakmor, R.; Hachinger, S.; Mazzali, P. A.; Stanishev, V.; Elias-Rosa, N.; Agnoletto, I.; Bufano, F.; Ergon, M.; Harutyunyan, A.; Inserra, C.; Kankare, E.; Kromer, M.; Navasardyan, H.; Nicolas, J.; Pastorello, A.; Prosperi, E.; Salgado, F.; Sollerman, J.; Stritzinger, M.; Turatto, M.; Valenti, S.; Hillebrandt, W.

    2011-04-01

    Extended optical and near-IR observations reveal that SN 2009dc shares a number of similarities with normal Type Ia supernovae (SNe Ia), but is clearly overluminous, with a (pseudo-bolometric) peak luminosity of log (L) = 43.47 (erg s-1). Its light curves decline slowly over half a year after maximum light [Δm15(B)true= 0.71], and the early-time near-IR light curves show secondary maxima, although the minima between the first and the second peaks are not very pronounced. The bluer bands exhibit an enhanced fading after ˜200 d, which might be caused by dust formation or an unexpectedly early IR catastrophe. The spectra of SN 2009dc are dominated by intermediate-mass elements and unburned material at early times, and by iron-group elements at late phases. Strong C II lines are present until ˜2 weeks past maximum, which is unprecedented in thermonuclear SNe. The ejecta velocities are significantly lower than in normal and even subluminous SNe Ia. No signatures of interaction with a circumstellar medium (CSM) are found in the spectra. Assuming that the light curves are powered by radioactive decay, analytic modelling suggests that SN 2009dc produced ˜1.8 M⊙ of 56Ni assuming the smallest possible rise time of 22 d. Together with a derived total ejecta mass of ˜2.8 M⊙, this confirms that SN 2009dc is a member of the class of possible super-Chandrasekhar-mass SNe Ia similar to SNe 2003fg, 2006gz and 2007if. A study of the hosts of SN 2009dc and other superluminous SNe Ia reveals a tendency of these SNe to explode in low-mass galaxies. A low metallicity of the progenitor may therefore be an important prerequisite for producing superluminous SNe Ia. We discuss a number of possible explosion scenarios, ranging from super-Chandrasekhar-mass white-dwarf progenitors over dynamical white-dwarf mergers and Type I? SNe to a core-collapse origin of the explosion. None of the models seems capable of explaining all properties of SN 2009dc, so that the true nature of this SN

  11. Scientific Temper among Academically High and Low Achieving Adolescent Girls

    ERIC Educational Resources Information Center

    Kour, Sunmeet

    2015-01-01

    The present study was undertaken to compare the scientific temper of high and low achieving adolescent girl students. Random sampling technique was used to draw the sample from various high schools of District Srinagar. The sample for the present study consisted of 120 school going adolescent girls (60 high and 60 low achievers). Data was…

  12. Mitigation of effects of beam-induced energy deposition in the LHC high-luminosity interaction regions

    SciTech Connect

    Nikolai V. Mokhov et al.

    2003-05-28

    Beam-induced energy deposition in the LHC high luminosity interaction region components is one of the serious limits for the machine performance. The results of further optimization and comprehensive MARS14 calculations in the IP1 and IP5 inner and outer triplets are summarized for the updated lattice, calculation model, baseline pp-collision source term, and for realistic engineering constraints on the hardware design. It is shown that the optimized layout and absorbers would provide a sufficient reduction of peak power density and dynamic heat load in the superconducting components with an adequate safety margin. Accumulated dose and residual dose rates in and around the region components are also kept below the tolerable limits in the proposed design.

  13. Smart and Bored: Are We Failing Our High Achievers?

    ERIC Educational Resources Information Center

    Cleaver, Samantha

    2008-01-01

    Some high achievers are not as easy to engage. Sometimes motivating high achievers is "a matter of being more sensitive to what they are interested in," says Don Ambrose, a professor of education at Rider University in New Jersey. But too often classrooms are not set up for that kind of sensitivity. Research shows that schools are consistently…

  14. Perspectives of High-Achieving Women on Teaching

    ERIC Educational Resources Information Center

    Snodgrass, Helen

    2010-01-01

    High-achieving women are significantly less likely to enter the teaching profession than they were just 40 years ago. Why? While the social and economic reasons for this decline have been well documented in the literature, what is lacking is a discussion with high-achieving women, as they make their first career decisions, about their perceptions…

  15. Ion-induced x-ray studies with a high luminosity von Hamos crystal spectrometer

    SciTech Connect

    Vane, C.R.; Smith, M.; Raman, S.; Heard, J.; Walkiewicz, T.

    1986-01-01

    A high-resolution, high-efficiency, von Hamos geometry, Bragg crystal x-ray spectrometer has been developed and mounted on a beamline at the Holifield Heavy Ion Research Facility at the Oak Ridge National Laboratory. Measurements have been made of K and L x-rays emitted from a variety of targets and projectiles. Instrument performance characteristics are reported here along with spectra from fast projectile ions and very low intensity target emission - areas of measurement for which this spectrometer is especially suitable.

  16. GRB 120422A/SN 2012bz: Bridging the gap between low- and high-luminosity gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Schulze, S.; Malesani, D.; Cucchiara, A.; Tanvir, N. R.; Krühler, T.; de Ugarte Postigo, A.; Leloudas, G.; Lyman, J.; Bersier, D.; Wiersema, K.; Perley, D. A.; Schady, P.; Gorosabel, J.; Anderson, J. P.; Castro-Tirado, A. J.; Cenko, S. B.; De Cia, A.; Ellerbroek, L. E.; Fynbo, J. P. U.; Greiner, J.; Hjorth, J.; Kann, D. A.; Kaper, L.; Klose, S.; Levan, A. J.; Martín, S.; O'Brien, P. T.; Page, K. L.; Pignata, G.; Rapaport, S.; Sánchez-Ramírez, R.; Sollerman, J.; Smith, I. A.; Sparre, M.; Thöne, C. C.; Watson, D. J.; Xu, D.; Bauer, F. E.; Bayliss, M.; Björnsson, G.; Bremer, M.; Cano, Z.; Covino, S.; D'Elia, V.; Frail, D. A.; Geier, S.; Goldoni, P.; Hartoog, O. E.; Jakobsson, P.; Korhonen, H.; Lee, K. Y.; Milvang-Jensen, B.; Nardini, M.; Nicuesa Guelbenzu, A.; Oguri, M.; Pandey, S. B.; Petitpas, G.; Rossi, A.; Sandberg, A.; Schmidl, S.; Tagliaferri, G.; Tilanus, R. P. J.; Winters, J. M.; Wright, D.; Wuyts, E.

    2014-06-01

    Context. At low redshift, a handful of gamma-ray bursts (GRBs) have been discovered with luminosities that are substantially lower (Liso ≲ 1048.5 erg s-1) than the average of more distant ones (Liso ≳ 1049.5 erg s-1). It has been suggested that the properties of several low-luminosity (low-L) GRBs are due to shock break-out, as opposed to the emission from ultrarelativistic jets. This has led to much debate about how the populations are connected. Aims: The burst at redshift z = 0.283 from 2012 April 22 is one of the very few examples of intermediate-L GRBs with a γ-ray luminosity of Liso ~ 1049.6-49.9 erg s-1 that have been detected up to now. With the robust detection of its accompanying supernova SN 2012bz, it has the potential to answer important questions on the origin of low- and high-L GRBs and the GRB-SN connection. Methods: We carried out a spectroscopy campaign using medium- and low-resolution spectrographs with 6-10-m class telescopes, which covered a time span of 37.3 days, and a multi-wavelength imaging campaign, which ranged from radio to X-ray energies over a duration of ~270 days. Furthermore, we used a tuneable filter that is centred at Hα to map star-formation in the host and the surrounding galaxies. We used these data to extract and model the properties of different radiation components and fitted the spectral energy distribution to extract the properties of the host galaxy. Results: Modelling the light curve and spectral energy distribution from the radio to the X-rays revealed that the blast wave expanded with an initial Lorentz factor of Γ0 ~ 50, which is a low value in comparison to high-L GRBs, and that the afterglow had an exceptionally low peak luminosity density of ≲2 × 1030 erg s-1 Hz-1 in the sub-mm. Because of the weak afterglow component, we were able to recover the signature of a shock break-out in an event that was not a genuine low-L GRB for the first time. At 1.4 hr after the burst, the stellar envelope had a blackbody

  17. THE ELECTRON ION COLLIDER. A HIGH LUMINOSITY PROBE OF THE PARTONIC SUBSTRUCTURE OF NUCLEONS AND NUCLEI.

    SciTech Connect

    EDITED BY M.S. DAVIS

    2002-02-01

    By the end of this decade, the advancement of current and planned research into the fundamental structure of matter will require a new facility, the Electron Ion Collider (EIC). The EIC will collide high-energy beams of polarized electrons from polarized protons and neutrons, and unpolarized beams of electrons off atomic nuclei with unprecedented intensity. Research at the EIC will lead to a detailed understanding of the structure of the proton, neutron, and atomic nuclei as described by Quantum Chromo-Dynamics (QCD), the accepted theory of the strong interaction. The EIC will establish quantitative answers to important questions by delivering dramatically increased precision over existing and planned experiments and by providing completely new experimental capabilities. Indeed, the EIC will probe QCD in a manner not possible previously. This document presents the scientific case for the design, construction and operation of the EIC. While realization of the EIC requires a significant advance in the development of efficient means of producing powerful beams of energetic electrons, an important consideration for choosing the site of the EIC is the planned upgrade to the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The upgrade planned for RHIC will fully meet the requirements for the ion beam for the EIC, providing a distinct advantage in terms of cost, schedule and the final operation.

  18. Test-Taking Strategies of High and Low Mathematics Achievers

    ERIC Educational Resources Information Center

    Hong, Eunsook; Sas, Maggie; Sas, John C.

    2006-01-01

    The authors explored test-preparation and test-taking strategies that high school students used in algebra tests. From a pool of high school students (N = 156), 61 students participated in interviews, and of those interviewed, 26 represented those who were high achieving as well as highly interested in mathematics (n = 15) vs. those who were low…

  19. Effectiveness of High Schools in Australia: Holding Power and Achievement.

    ERIC Educational Resources Information Center

    Ainley, John; Sheret, Michael

    High schools in Australia are increasingly expected to be effective in holding students at school to year 12 as well as in promoting achievement. Analysis of quantitative data gathered as part of a longitudinal study of 22 New South Wales (Australia) schools shows that schools differ in their holding power as well as in the achievement levels of…

  20. Tracking and Detracking: High Achievers in Massachusetts Middle Schools

    ERIC Educational Resources Information Center

    Loveless, Tom

    2009-01-01

    This study examines tracking--the practice of grouping students into separate classes or courses based on their prior academic achievement--at the middle-school level, and the percentage of high-achieving students in tracked and untracked schools. It focuses on Massachusetts, a leader in "reforming" tracking, and the changes that have…

  1. Some Correlates of High School Foreign Language Achievement.

    ERIC Educational Resources Information Center

    Beanblossom, Gary F.

    This paper investigates the influences of traditional kinds of verbal and quantitative achievement and aptitude variables on high school foreign language achievement, as measured by Modern Language Association and University of Washington tests of language skills administered to entering college students. The report focuses on: (1) the sample and…

  2. Biculturalism and Academic Achievement of African American High School Students

    ERIC Educational Resources Information Center

    Rust, Jonathan P.; Jackson, Margo A.; Ponterotto, Joseph G.; Blumberg, Fran C.

    2011-01-01

    Biculturalism was examined as a factor that may positively affect the academic achievement of African American high school students, beyond cultural identity and self-esteem. Hierarchical regression analyses determined that cultural identity and academic self-esteem were important factors for academic achievement, but not biculturalism.…

  3. Mobility and Student Achievement in High Poverty Schools

    ERIC Educational Resources Information Center

    Dalton, Janet Denise

    2013-01-01

    Student mobility is an issue for high poverty schools in the shadow of increased rigor and accountability for student performance. Whereas mobility is not a sole cause for poor achievement, it is a contributing factor for students in poverty who are already considered to be at risk of low achievement. Student mobility creates a hardship for…

  4. Common envelope mechanisms: constraints from the X-ray luminosity function of high-mass X-ray binaries

    SciTech Connect

    Zuo, Zhao-Yu; Li, Xiang-Dong E-mail: lixd@nju.edu.cn

    2014-12-10

    We use the measured X-ray luminosity function (XLF) of high-mass X-ray binaries (HMXBs) in nearby star-forming galaxies to constrain the common envelope (CE) mechanisms, which play a key role in governing the binary evolution. We find that the XLF can be reproduced quite closely under both CE mechanisms usually adopted, i.e., the α{sub CE} formalism and the γ algorithm, with a reasonable range of parameters considered. Provided that the parameter combination is the same, the γ algorithm is likely to produce more HMXBs than the α{sub CE} formalism, by a factor of up to ∼10. In the framework of the α{sub CE} formalism, a high value of α{sub CE} is required to fit the observed XLF, though it does not significantly affect the global number of the HMXB populations. We present the detailed components of the HMXB populations under the γ algorithm and compare them with those in Zuo et al. and observations. We suggest the distinct observational properties, as well as period distributions of HMXBs, may provide further clues to discriminate between these two types of CE mechanisms.

  5. Probing TeV scale top-philic resonances with boosted top-tagging at the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Kim, Jeong Han; Kong, Kyoungchul; Lee, Seung J.; Mohlabeng, Gopolang

    2016-08-01

    We investigate the discovery potential of singly produced top-philic resonances at the high luminosity (HL) LHC in the four-top final state. Our analysis spans over the fully hadronic, semileptonic, and same-sign dilepton channels where we present concrete search strategies adequate to a boosted kinematic regime and high jet-multiplicity environments. We utilize the template overlap method with newly developed template observables for tagging boosted top quarks, a large-radius jet variable MJ , and customized b -tagging tactics for background discrimination. Our results show that the same-sign dilepton channel gives the best sensitivity among the considered channels, with an improvement of significance up to 10%-20% when combined with boosted top-tagging. Both the fully hadronic and semileptonic channels yield comparable discovery potential and contribute to further enhancements in the sensitivity by combining all channels. Finally, we show the sensitivity of a top-philic resonance at the LHC and HL-LHC by showing the 2 σ exclusion limit and 5 σ discovery reach, including a combination of all three channels.

  6. Attitudes and Opinions from the Nation's High Achieving Teens: 29th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This report presents the 1998 statistical findings of the annual survey to determine the attitudes of national high school student leaders. Questionnaires were completed by 3,123 high school juniors and seniors, all of whom were selected for recognition in "Who's Who among American High School Students." In addition to demographic information, the…

  7. MID-INFRARED DETERMINATION OF TOTAL INFRARED LUMINOSITY AND STAR FORMATION RATES OF LOCAL AND HIGH-REDSHIFT GALAXIES

    SciTech Connect

    Rujopakarn, W.; Rieke, G. H.; Weiner, B. J.; Perez-Gonzalez, P.; Rex, M.; Walth, G. L.; Kartaltepe, J. S.

    2013-04-10

    We demonstrate estimating the total infrared luminosity, L(TIR), and star formation rates (SFRs) of star-forming galaxies at redshift 0 < z < 2.8 from single-band 24 {mu}m observations, using local spectral energy distribution (SED) templates without introducing additional free parameters. Our method is based on characterizing the SEDs of galaxies as a function of their L(TIR) surface density, which is motivated by the indications that the majority of IR luminous star-forming galaxies at 1 < z < 3 have extended star-forming regions, in contrast to the strongly nuclear concentrated, merger-induced starbursts in local luminous and ultraluminous IR galaxies. We validate our procedure for estimating L(TIR) by comparing the resulting L(TIR) with those measured from far-IR observations, such as those from Herschel in the Extended Chandra Deep Field South (ECDFS) and Hubble Deep Field North (HDFN), as well as L(TIR) measured from stacked far-IR observations at redshift 0 < z < 2.8. Active galactic nuclei were excluded using X-ray and 3.6-8.0 {mu}m observations, which are generally available in deep cosmological survey fields. The Gaussian fits to the distribution of the discrepancies between the L(TIR) measurements from single-band 24 {mu}m and Herschel observations in the ECDFS and HDFN samples have {sigma} < 0.1 dex, with {approx}10% of objects disagreeing by more than 0.2 dex. Since the 24 {mu}m estimates are based on SEDs for extended galaxies, this agreement suggests that {approx}90% of IR galaxies at high z are indeed much more physically extended than local counterparts of similar L(TIR), consistent with recent independent studies of the fractions of galaxies forming stars in the main-sequence and starburst modes, respectively. Because we have not introduced empirical corrections to enhance these estimates, in principle, our method should be applicable to lower luminosity galaxies. This will enable use of the 21 {mu}m band of the Mid-Infrared Instrument on board

  8. The "Renaissance Child": High Achievement and Gender in Late Modernity

    ERIC Educational Resources Information Center

    Skelton, Christine; Francis, Becky

    2012-01-01

    This paper draws on the concept of the "Renaissance Child" to illustrate the ways in which gender influences the opportunities and possibilities of high-achieving pupils. Using data from a study of 12-13-year high-achieving boys and girls based in schools in England, the paper considers the ways in which a group of popular boys was able to show an…

  9. Attitudes and Opinions from the Nation's High Achieving Teens: 27th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This report details the 27th annual study to examine the attitudes of student leaders in U.S. high schools. Participating in the survey were 3,370 adolescents, primarily 16- and 17-year-olds, who had been featured in the 1996 edition of "Who's Who Among American High School Students." The report presents demographic information on the survey…

  10. Attitudes and Opinions from the Nation's High Achieving Teens: 28th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This report details the 28th annual study to examine the attitudes of student leaders in U.S. high schools. Participating in the survey were 3,210 adolescents, primarily 16- and 17-year-olds, who had been featured in the 1997 edition of "Who's Who Among American High School Students." The report presents demographic information on the survey…

  11. SPECTRAL ENERGY DISTRIBUTIONS OF LOW-LUMINOSITY RADIO GALAXIES AT z {approx}1-3: A HIGH-z VIEW OF THE HOST/AGN CONNECTION

    SciTech Connect

    Baldi, Ranieri D.; Chiaberge, Marco; Rodriguez-Zaurin, Javier; Deustua, Susana; Sparks, William B.; Capetti, Alessandro

    2013-01-01

    We study the spectral energy distributions, SEDs (from FUV to MIR bands), of the first sizeable sample of 34 low-luminosity radio galaxies at high redshifts, selected in the COSMOS field. To model the SEDs, we use two different template-fitting techniques: (1) the Hyperz code that only considers single stellar templates and (2) our own developed technique 2SPD that also includes the contribution from a young stellar population and dust emission. The resulting photometric redshifts range from z {approx} 0.7 to 3 and are in substantial agreement with measurements from earlier work, but significantly more accurate. The SED of most objects is consistent with a dominant contribution from an old stellar population with an age {approx}1-3 Multiplication-Sign 10{sup 9} years. The inferred total stellar mass range is {approx}10{sup 10}-10{sup 12} M {sub Sun }. Dust emission is needed to account for the 24 {mu}m emission in 15 objects. Estimates of the dust luminosity yield values in the range L {sub dust} {approx} 10{sup 43.5}-10{sup 45.5} erg s{sup -1}. The global dust temperature, crudely estimated for the sources with an MIR excess, is {approx}300-850 K. A UV excess is often observed with a luminosity in the range {approx}10{sup 42}-10{sup 44} erg s{sup -1} at 2000 A rest frame. Our results show that the hosts of these high-z low-luminosity radio sources are old massive galaxies, similar to the local FR Is. However, the UV and MIR excesses indicate the possible significant contribution from star formation and/or nuclear activity in such bands, not seen in low-z FR Is. Our sources display a wide variety of properties: from possible quasars at the highest luminosities to low-luminosity old galaxies.

  12. High-energy cosmic-ray nuclei from high- and low-luminosity gamma-ray bursts and implications for multimessenger astronomy

    SciTech Connect

    Murase, Kohta; Nagataki, Shigehiro; Ioka, Kunihito; Nakamura, Takashi

    2008-07-15

    Gamma-ray bursts (GRBs) are one of the candidates of ultrahigh-energy (> or approx. 10{sup 18.5} eV) cosmic-ray (UHECR) sources. We investigate high-energy cosmic-ray acceleration including heavy nuclei in GRBs by using Geant 4, and discuss its various implications, taking both high-luminosity (HL) and low-luminosity (LL) GRBs into account. This is because LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population. We show that not only protons, but also heavier nuclei can be accelerated up to ultrahigh energies in the internal, (external) reverse, and forward shock models. We also show that the condition for ultrahigh-energy heavy nuclei such as iron to survive is almost the same as that for {approx}TeV gamma rays to escape from the source and for high-energy neutrinos not to be much produced. The multimessenger astronomy by neutrino and GeV-TeV gamma-ray telescopes such as IceCube and KM3Net, GLAST and MAGIC will be important to see whether GRBs can be accelerators of ultrahigh-energy heavy nuclei. We also demonstrate expected spectra of high-energy neutrinos and gamma rays, and discuss their detectabilities. In addition, we discuss implications of the GRB-UHECR hypothesis. We point out, since the number densities of HL GRBs and LL GRBs are quite different, its determination by UHECR observations is also important.

  13. Attitudes and Opinions from the Nation's High Achieving Teens. 25th Annual Survey of High Achievers.

    ERIC Educational Resources Information Center

    Who's Who among American High School Students, Lake Forest, IL.

    This survey was conducted during the spring of 1994 for the purpose of determining the attitudes of student leaders in the nation's high schools. Eight thousand surveys were sent out to students, of which 3177 were returned. All students surveyed were members of the junior or senior class during the 1993-94 academic year. They were selected for…

  14. Student Achievement for Whom? High-Performing and Still "Playing the Game," the Meaning of School Achievement among High Achieving African American Students

    ERIC Educational Resources Information Center

    Wiggan, Greg

    2014-01-01

    The preponderance of the research on African American students has generally focused on issues of school failure and underperformance. While the literature on high achieving Black students is sparse, very little is known about these students' school experiences and the meanings that they assign to achievement. Using student-based inquiry…

  15. High School Employment and Academic Achievement: A Note for Educators

    ERIC Educational Resources Information Center

    Keister, Mary; Hall, Joshua

    2010-01-01

    Educators are often in a position to affect student decisions to work during the school term. This study reviews and summarizes the literature on the effect that employment during high school has on academic achievement. The available evidence suggests that part-time jobs for high school students are beneficial as long as the number of hours…

  16. Exploring High-Achieving Students' Images of Mathematicians

    ERIC Educational Resources Information Center

    Aguilar, Mario Sánchez; Rosas, Alejandro; Zavaleta, Juan Gabriel Molina; Romo-Vázquez, Avenilde

    2016-01-01

    The aim of this study is to describe the images that a group of high-achieving Mexican students hold of mathematicians. For this investigation, we used a research method based on the Draw-A-Scientist Test (DAST) with a sample of 63 Mexican high school students. The group of students' pictorial and written descriptions of mathematicians assisted us…

  17. Brain Hemisphericity and Mathematics Achievement of High School Students

    ERIC Educational Resources Information Center

    Fernandez, Sanny F.

    2011-01-01

    This study aimed to find out the brain hemisphericity and mathematics achievement of high school students. The respondents of the study were the 168 first year high school students of Colegio de San Jose, during school year 2010-2011 who were chosen through stratified random sampling. The descriptive and interview methods of research were used in…

  18. Higher order mode filter design for double quarter wave crab cavity for the LHC high luminosity upgrade

    SciTech Connect

    Xiao, B.; Belomestnykh, S.; Ben-Zvi, I.; Burt, G.; Calaga, R.; Capatina, O.; Hall, B.; Jones, T.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Double Quarter Wave Crab Cavity (DQWCC) was designed for the Large Hadron Collider (LHC) luminosity upgrade. A compact Higher Order Mode (HOM) filter with wide stop band at the deflecting mode is developed for this cavity. Multiphysics finite element simulation results are presented. The integration of this design to the cavity cryomodule is described.

  19. An Analysis of High School Mathematics Achievement and English Language Arts Achievement as Predictors of Science Achievement

    ERIC Educational Resources Information Center

    Edwards, Anthony C.

    2012-01-01

    Science assessments require students to read and comprehend questions and to solve mathematical problems. The purpose of this study is to determine whether the following variables can be used to predict science achievement: English language arts achievement, mathematics achievement, socioeconomic status (SES), limited English proficiency (LEP)…

  20. UPGRADING RHIC FOR HIGHER LUMINOSITY.

    SciTech Connect

    MACKAY,W.; BEN-ZVI,I.; BRENNAN,J.M.; HARRISON,M.; KEWISCH,J.; PEGGS,S.; ROSER,T.; TRBOJEVIC,D.; PARKHOMCHUK,V.

    2001-06-18

    While RHIC has only just started running for its heavy ion physics program, in the first run last summer, we achieved 10% of the design luminosity. In this paper we discuss plans for increasing the luminosity by a factor of 35 beyond the nominal design. A factor of 4 should be straightforward by doubling the number of bunches per ring and squeezing the {beta}* from 2 to 1 m at selected interaction points. An additional factor of 8 to 10 could be possible by using electron cooling to counteract intrabeam scattering and reduce emittances of the beams.

  1. Unidentified IRAS sources: Ultrahigh luminosity galaxies

    NASA Technical Reports Server (NTRS)

    Houck, J. R.; Schneider, D. P.; Danielson, G. E.; Beichman, C. A.; Lonsdale, C. J.; Neugebauer, G.; Soifer, B. T.

    1985-01-01

    Optical imaging and spectroscopy measurements were obtained for six of the high galactic latitude infrared sources reported by Houck, et al. (1984) from the IRAS survey to have no obvious optical counterparts on the POSS prints. All are identified with visually faint galaxies that have total luminosities in the range 5 x 10 to the 11th power stellar luminosity to 5 x 10 to the 12th power stellar luminosity. This luminosity emerges virtually entirely in the infrared. The origin of the luminosity, which is one to two orders of magnitude greater than that of normal galaxies, is not known at this time.

  2. LUMINOSITY OPTIMIZATION USING AUTOMATED IR STEERING AT RHIC.

    SciTech Connect

    DREES,A.D'OTTAVIO,T.

    2004-07-05

    The goal of the RHIC 2004 Au-Au run was to maximize the achieved integrated luminosity. One way is to increase beam currents and minimize beam transverse emittances. Another important ingredient is the minimization of time spent on activities postponing the declaration of ''physics conditions'', i.e. stable beam conditions allowing the experimental detectors to take data. Since collision rates are particularly high in the beginning of the store the integrated luminosity benefits considerably from any minute saved early in the store. In the RHIC run 2004 a new IR steering application uses luminosity monitor signals as a feedback for a fully automated steering procedure. This report gives an overview of the used procedure and summarizes the achieved results.

  3. Behind the High Achievement of East Asian Students.

    ERIC Educational Resources Information Center

    Leung, Frederick K. S.

    2002-01-01

    Studied reasons for the high achievement students from Hong Kong, Japan, South Korea, and Singapore on the Third International Mathematics and Science Study (TIMSS). Questionnaire data provided by students participating show that the superior results of these students may have come at the expense of other aspects of student development. Results…

  4. Progress Lags in High School, Especially for Advanced Achievers

    ERIC Educational Resources Information Center

    Education Digest: Essential Readings Condensed for Quick Review, 2012

    2012-01-01

    This report by the Center on Education Policy (CEP), an independent nonprofit organization, examines trends in the achievement of high school students on the state reading/English language arts (ELA) and mathematics tests used for accountability under the No Child Left Behind Act (NCLB). This study confirms that there is reason for concern about…

  5. Learning Environment, Motivation, and Achievement in High School Science.

    ERIC Educational Resources Information Center

    Nolen, Susan Bobbitt

    2003-01-01

    Examines the relationship between high school students' perceptions of their science learning environments and their motivation, learning strategies, and achievement. Discusses the focus of shared perceptions and instruction and indicates that shared perceptions focused on understanding and independent thinking positively predicted students'…

  6. High Achieving Girls in Mathematics: What's Wrong with Working Hard?

    ERIC Educational Resources Information Center

    Howe, Ann C.; Berenson, Sarah B.

    2003-01-01

    The participation of women in graduate studies and mathematics-related careers remains a social and economic problem in the United States. Part of a larger study to understand this lack of participation, here we present preliminary findings of girls who are high achievers in middle grades mathematics. This interpretive study documents girls'…

  7. Relationship between High School Leadership Team Practices and Student Achievement

    ERIC Educational Resources Information Center

    McInnis, Timothy M.

    2009-01-01

    This study investigated if a relationship existed between student achievement in 10th grade Missouri Assessment Program mathematics and 11th grade communication arts scores in 2007 and high school leadership team perceptions of the extent to which they demonstrated leadership practices. The secondary purpose was to compare perceptional…

  8. Improving Student Achievement in Today's High Schools: What Works.

    ERIC Educational Resources Information Center

    Shields, Marie S.

    This paper is based on a study of two high schools in Maine that achieved outstanding and consistent gains in English, math, and science over a 5-year period. Three strands of inquiry were used for the study: surveys, interviews, and observations. A multiple-perspective approach was used to integrate the information so as to evaluate the…

  9. Mercer Middle School Case Study: High Science and Math Achievement

    ERIC Educational Resources Information Center

    Washington State Board of Education, 2010

    2010-01-01

    To spotlight effective practices, the Washington State Board of Education (SBE) is highlighting schools that are closing achievement gaps and performing at high levels. In 2009, the SBE partnered with the Office of Superintendent of Public Instruction (OSPI) to create the Washington Accountability Index. The Index is a new way to measure schools'…

  10. Supplementary Education: The Hidden Curriculum of High Academic Achievement

    ERIC Educational Resources Information Center

    Gordon, Edmund W., Ed.; Bridglall, Beatrice L., Ed.; Meroe, Aundra Saa, Ed.

    2004-01-01

    In this book, the editors argue that while access to schools that enable and expect academic achievement is a necessary ingredient for the education of students, schools alone may not be sufficient to ensure universally high levels of academic development. Supplemental educational experiences may also be needed. The idea of supplementary education…

  11. Analysis of Three High-Achieving Young Adolescent Girls

    ERIC Educational Resources Information Center

    Lim, Jae Hoon; Chae, Jeong-Lim; Schinck-Mikel, Amelie G.; Watson, Jimmy

    2013-01-01

    This paper presents an in-depth cross-case analysis of three high-achieving young adolescent girls who had contrasting mathematics learning experiences during the first year of middle school. In particular, this study examines the foundation for their motivation, as well as the dominant mode of learning and academic engagement in relation to three…

  12. Test Score Decline Among High Achievers: Policy Implications.

    ERIC Educational Resources Information Center

    Goldman, Jerrold; Hsia, Jayjia

    Since 1967, the mean Scholastic Aptitude Test (SAT) score has declined. Likewise, the numbers of candidates receiving high SAT scores have been decreasing steadily. The same downward trend in student achievement can be seen among student groups from grade 4 through post graduate studies. In recent years, policy has been directed towards making…

  13. Student Achievement through the Development of Complete High School Culture

    ERIC Educational Resources Information Center

    Lamphere, Michael Frederick, Jr.

    2012-01-01

    This dissertation undertook an investigation of school culture and achievement in the high school setting. The national data set ELS:2002 was used as the pool of variables because it allows for a complete picture of school culture comprising students, parents, administrators, and teachers. The data were selected based on current literature and…

  14. The High Trust Classroom: Raising Achievement from the Inside Out

    ERIC Educational Resources Information Center

    Moore, Lonnie

    2009-01-01

    This book provides a roadmap to developing a high-trust classroom, a classroom: (1) With increased student achievement; (2) With few discipline problems; (3) Where students are intrinsically motivated; and (4) Where the teacher can confidently use creative lesson planning. The author presents a simple step by step approach to earning the trust of…

  15. Self-Esteem and Academic Achievement of High School Students

    ERIC Educational Resources Information Center

    Moradi Sheykhjan, Tohid; Jabari, Kamran; Rajeswari, K.

    2014-01-01

    The primary purpose of this study was to determine the influence of self-esteem on academic achievement among high school students in Miandoab City of Iran. The methodology of the research is descriptive and correlation that descriptive and inferential statistics were used to analyze the data. Statistical Society includes male and female high…

  16. Learning environment, motivation, and achievement in high school science

    NASA Astrophysics Data System (ADS)

    Bobbitt Nolen, Susan

    2003-04-01

    In a study of the relationship between high school students' perceptions of their science learning environments and their motivation, learning strategies, and achievement, 377 students in 22 introductory science classrooms completed surveys in the fall and spring of their ninth-grade year. Hierarchical linear regression was used to model the effects of variables at both the classroom and individual level simultaneously. High intraclass agreement (indicated by high parameter reliability) on all classroom environment measures indicated that students shared perceptions of the classroom learning environment. Controlling for other factors, shared perceptions that only the most able could succeed in science classrooms and that instruction was fast-paced and focused on correct answers negatively predicted science achievement, as measured on a districtwide curriculum-linked test. Shared perceptions that classrooms focused on understanding and independent thinking positively predicted students' self-reported satisfaction with learning. Implications of these results for both teaching and research into classroom environments are discussed.

  17. Parent Involvement Practices of High-Achieving Elementary Science Students

    NASA Astrophysics Data System (ADS)

    Waller, Samara Susan

    This study addressed a prevalence of low achievement in science courses in an urban school district in Georgia. National leaders and educators have identified the improvement of science proficiency as critical to the future of American industry. The purpose of this study was to examine parent involvement in this school district and its contribution to the academic achievement of successful science students. Social capital theory guided this study by suggesting that students achieve best when investments are made into their academic and social development. A collective case study qualitative research design was used to interview 9 parent participants at 2 elementary schools whose children scored in the exceeds category on the Science CRCT. The research questions focused on what these parents did at home to support their children's academic achievement. Data were collected using a semi-structured interview protocol and analyzed through the categorical aggregation of transcribed interviews. Key findings revealed that the parents invested time and resources in 3 practices: communicating high expectations, supporting and developing key skills, and communicating with teachers. These findings contribute to social change at both the local and community level by creating a starting point for teachers, principals, and district leaders to reexamine the value of parent input in the educational process, and by providing data to support the revision of current parent involvement policies. Possibilities for further study building upon the findings of this study may focus on student perceptions of their parents' parenting as it relates to their science achievement.

  18. The Will to Achieve: A Phenomenological Study of the Experiences of African American High Achieving Students and Their Parents

    ERIC Educational Resources Information Center

    Spencer, Natalie Faye

    2012-01-01

    The purpose of this research study was to understand the experiences of high achieving African American students and their parents. The experiences of high achieving African American students and their parents have been missing from literature on the academic achievement of African American students. Much of the literature that has been published…

  19. Achieving High Performance on the i860 Microprocessor

    NASA Technical Reports Server (NTRS)

    Lee, King; Kutler, Paul (Technical Monitor)

    1998-01-01

    The i860 is a high performance microprocessor used in the Intel Touchstone project. This paper proposes a paradigm for programming the i860 that is modelled on the vector instructions of the Cray computers. Fortran callable assembler subroutines were written that mimic the concurrent vector instructions of the Cray. Cache takes the place of vector registers. Using this paradigm we have achieved twice the performance of compiled code on a traditional solve.

  20. B_c Meson Production Around the Z^0 Peak at a High Luminosity e^+ e^- Collider

    SciTech Connect

    Yang, Zhi; Wu, Xing-Gang; Chen, Gu; Liao, Qi-Li; Zhang, Jia-Wei; /Chongqing U.

    2012-05-22

    Considering the possibility to build an e{sup +}e{sup -} collider at the energies around the Z{sup 0}-boson resonance with a planned luminosity so high as L {proportional_to} 10{sup 34} {approx} 10{sup 36} cm{sup -2}s{sup -1} (super Z-factory), we make a detailed discussion on the (c{bar b})-quarkonium production through e{sup +}e{sup -} {yields} (c{bar b})[n] + b + {bar c} within the framework of non-relativistic QCD. Here [n] stands for the Fock-states |(c{sub b}){sub 1}[{sup 1}S{sub 0}]>, |(c{bar b})8[{sup 1}S{sub 0}]g>, |(c{bar b} ){sub 1}[{sup 3}S{sub 1}]>, |(c{bar b}){sub 8}[{sup 3}S{sub 1}]g>, |(c{bar b}){sub 1}[{sup 1}P{sub 1}]> and |(c{bar b}){sub 1}[{sup 3}P{sub J}]> (with J = (1, 2, 3)) respectively. To simplify the hard-scattering amplitude as much as possible and to derive analytic expressions for the purpose of future events simulation, we adopt the 'improved trace technology' to do our calculation, which deals with the hard scattering amplitude directly at the amplitude level other than the conventional way at the squared-amplitude level. Total cross-section uncertainties caused by the quark masses are predicted by taking m{sub c} = 1.50 {+-} 0.30 GeV and m{sub b} = 4.90 {+-} 0.40 GeV. If all higher (c{bar b})-quarkonium states decay to the ground state B{sub c} (|(c{bar b}){sub 1}[{sup 1}S{sub 0}]>) with 100% efficiency, we obtain {sigma}{sub e{sup +}+e{sup -}{yields}B{sub c}+b+{bar c}} = 5.190{sub -2.419}{sup +6.222} pb, which shows that about 10{sup 5} {approx} 10{sup 7} B{sub c} events per operation year can be accumulated in the super Z-factory. If taking the collider energy runs slightly off the Z{sup 0}-peak, i.e. {radical}S = (1.00 {+-} 0.05)m{sub Z}, the total cross-section shall be lowered by about one-order from its peak value. Such a super Z-factory shall provide another useful platform to study the properties of B{sub c} meson, or even the properties of its excited P-wave states, in addition to its production at the hadronic colliders

  1. Experiences of High-Achieving High School Students Who Have Taken Multiple Concurrent Advanced Placement Courses

    ERIC Educational Resources Information Center

    Milburn, Kristine M.

    2011-01-01

    Problem: An increasing number of high-achieving American high school students are enrolling in multiple Advanced Placement (AP) courses. As a result, high schools face a growing need to understand the impact of taking multiple AP courses concurrently on the social-emotional lives of high-achieving students. Procedures: This phenomenological…

  2. STELLAR VELOCITY DISPERSION MEASUREMENTS IN HIGH-LUMINOSITY QUASAR HOSTS AND IMPLICATIONS FOR THE AGN BLACK HOLE MASS SCALE

    SciTech Connect

    Grier, C. J.; Martini, P.; Peterson, B. M.; Pogge, R. W.; Zu, Y.; Watson, L. C.; Bentz, M. C.; Dasyra, K. M.; Dietrich, M.; Ferrarese, L.

    2013-08-20

    We present new stellar velocity dispersion measurements for four luminous quasars with the Near-Infrared Integral Field Spectrometer instrument and the ALTAIR laser guide star adaptive optics system on the Gemini North 8 m telescope. Stellar velocity dispersion measurements and measurements of the supermassive black hole (BH) masses in luminous quasars are necessary to investigate the coevolution of BHs and galaxies, trace the details of accretion, and probe the nature of feedback. We find that higher-luminosity quasars with higher-mass BHs are not offset with respect to the M{sub BH}-{sigma}{sub *} relation exhibited by lower-luminosity active galactic nuclei (AGNs) with lower-mass BHs, nor do we see correlations with galaxy morphology. As part of this analysis, we have recalculated the virial products for the entire sample of reverberation-mapped AGNs and used these data to redetermine the mean virial factor (f) that places the reverberation data on the quiescent M{sub BH}-{sigma}{sub *} relation. With our updated measurements and new additions to the AGN sample, we obtain (f) = 4.31 {+-} 1.05, which is slightly lower than, but consistent with, most previous determinations.

  3. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  4. Generating high temperature tolerant transgenic plants: Achievements and challenges.

    PubMed

    Grover, Anil; Mittal, Dheeraj; Negi, Manisha; Lavania, Dhruv

    2013-05-01

    Production of plants tolerant to high temperature stress is of immense significance in the light of global warming and climate change. Plant cells respond to high temperature stress by re-programming their genetic machinery for survival and reproduction. High temperature tolerance in transgenic plants has largely been achieved either by over-expressing heat shock protein genes or by altering levels of heat shock factors that regulate expression of heat shock and non-heat shock genes. Apart from heat shock factors, over-expression of other trans-acting factors like DREB2A, bZIP28 and WRKY proteins has proven useful in imparting high temperature tolerance. Besides these, elevating the genetic levels of proteins involved in osmotic adjustment, reactive oxygen species removal, saturation of membrane-associated lipids, photosynthetic reactions, production of polyamines and protein biosynthesis process have yielded positive results in equipping transgenic plants with high temperature tolerance. Cyclic nucleotide gated calcium channel proteins that regulate calcium influxes across the cell membrane have recently been shown to be the key players in induction of high temperature tolerance. The involvement of calmodulins and kinases in activation of heat shock factors has been implicated as an important event in governing high temperature tolerance. Unfilled gaps limiting the production of high temperature tolerant transgenic plants for field level cultivation are discussed.

  5. The CMS pixel luminosity telescope

    NASA Astrophysics Data System (ADS)

    Kornmayer, A.

    2016-07-01

    The Pixel Luminosity Telescope (PLT) is a new complement to the CMS detector for the LHC Run II data taking period. It consists of eight 3-layer telescopes based on silicon pixel detectors that are placed around the beam pipe on each end of CMS viewing the interaction point at small angle. A fast 3-fold coincidence of the pixel planes in each telescope will provide a bunch-by-bunch measurement of the luminosity. Particle tracking allows collision products to be distinguished from beam background, provides a self-alignment of the detectors, and a continuous in-time monitoring of the efficiency of each telescope plane. The PLT is an independent luminometer, essential to enhance the robustness on the measurement of the delivered luminosity and to reduce its systematic uncertainties. This will allow to determine production cross-sections, and hence couplings, with high precision and to set more stringent limits on new particle production.

  6. Unlocking Emergent Talent: Supporting High Achievement of Low-Income, High Ability Students

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula; Clarenbach, Jane

    2012-01-01

    This report takes a comprehensive look at achievement for low-income promising learners--past, present, and future. At its core, it challenges the nation to move beyond its near-singular focus of achieving minimum performance for all students, to identifying and developing the talent of all students who are capable of high achievement, including…

  7. Achieving high energy absorption capacity in cellular bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    Chen, S. H.; Chan, K. C.; Wu, F. F.; Xia, L.

    2015-05-01

    Cellular bulk metallic glasses (BMGs) have exhibited excellent energy-absorption performance by inheriting superior strength from the parent BMGs. However, how to achieve high energy absorption capacity in cellular BMGs is vital but mysterious. In this work, using step-by-step observations of the deformation evolution of a series of cellular BMGs, the underlying mechanisms for the remarkable energy absorption capacity have been investigated by studying two influencing key factors: the peak stress and the decay of the peak stress during the plastic-flow plateau stages. An analytical model of the peak stress has been proposed, and the predicted results agree well with the experimental data. The decay of the peak stress has been attributed to the geometry change of the macroscopic cells, the formation of shear bands in the middle of the struts, and the “work-softening” nature of BMGs. The influencing factors such as the effect of the strut thickness and the number of unit cells have also been investigated and discussed. Strategies for achieving higher energy absorption capacity in cellular BMGs have been proposed.

  8. Achieving high energy absorption capacity in cellular bulk metallic glasses

    PubMed Central

    Chen, S. H.; Chan, K. C.; Wu, F. F.; Xia, L.

    2015-01-01

    Cellular bulk metallic glasses (BMGs) have exhibited excellent energy-absorption performance by inheriting superior strength from the parent BMGs. However, how to achieve high energy absorption capacity in cellular BMGs is vital but mysterious. In this work, using step-by-step observations of the deformation evolution of a series of cellular BMGs, the underlying mechanisms for the remarkable energy absorption capacity have been investigated by studying two influencing key factors: the peak stress and the decay of the peak stress during the plastic-flow plateau stages. An analytical model of the peak stress has been proposed, and the predicted results agree well with the experimental data. The decay of the peak stress has been attributed to the geometry change of the macroscopic cells, the formation of shear bands in the middle of the struts, and the “work-softening” nature of BMGs. The influencing factors such as the effect of the strut thickness and the number of unit cells have also been investigated and discussed. Strategies for achieving higher energy absorption capacity in cellular BMGs have been proposed. PMID:25973781

  9. Achieving High Resolution Timer Events in Virtualized Environment

    PubMed Central

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs—Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  10. Achieving High Resolution Timer Events in Virtualized Environment.

    PubMed

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  11. Design considerations for achieving high vacuum integrity in fusion devices

    SciTech Connect

    Fuller, G.M.; Haines, J.R.

    1983-01-01

    Achieving high vacuum integrity in fusion devices requires close attention to both the overall system configuration and the design details of joints and seals. This paper describes the factors in selecting the system configuration, from a vacuum standpoint, for the Princeton Plasma Physics Laboratory (PPPL) DCT-8 Tokamak device. The DCT-8 (driven current tokamak) is the eighth design in a series of tokamak concepts defined to cover the magnetic confinement and development gap between the Tokamak Fusion Test Reactor (TFTR) and the Engineering Test Reactor (ETR). Leak detection concept development is considered a vital activity, as well as the definition of a configuration that minimizes the consequences of leaks. A major part of the vacuum boundaries of the magnet system and the plasma system is common. For the major penetrations, primary and secondary seals are provided with vacuum control over the region between seals. The intent is to instrument these cavities and provide automated recordings of these measurements for leak maintenance.

  12. Luminosity determination at HERA-B

    NASA Astrophysics Data System (ADS)

    Abt, I.; Adams, M.; Agari, M.; Albrecht, H.; Aleksandrov, A.; Amaral, V.; Amorim, A.; Aplin, S. J.; Aushev, V.; Bagaturia, Y.; Balagura, V.; Bargiotti, M.; Barsukova, O.; Bastos, J.; Batista, J.; Bauer, C.; Bauer, Th. S.; Belkov, A.; Belkov, Ar.; Belotelov, I.; Bertin, A.; Bobchenko, B.; Böcker, M.; Bogatyrev, A.; Bohm, G.; Bräuer, M.; Bruinsma, M.; Bruschi, M.; Buchholz, P.; Buran, T.; Carvalho, J.; Conde, P.; Cruse, C.; Dam, M.; Danielsen, K. M.; Danilov, M.; De Castro, S.; Deppe, H.; Dong, X.; Dreis, H. B.; Egorytchev, V.; Ehret, K.; Eisele, F.; Emeliyanov, D.; Essenov, S.; Fabbri, L.; Faccioli, P.; Feuerstack-Raible, M.; Flammer, J.; Fominykh, B.; Funcke, M.; Garrido, Ll.; Gellrich, A.; Giacobbe, B.; Gläß, J.; Goloubkov, D.; Golubkov, Y.; Golutvin, A.; Golutvin, I.; Gorbounov, I.; Gorišek, A.; Gouchtchine, O.; Goulart, D. C.; Gradl, S.; Gradl, W.; Grimaldi, F.; Groth-Jensen, J.; Guilitsky, Yu.; Hansen, J. D.; Hernández, J. M.; Hofmann, W.; Hohlmann, M.; Hott, T.; Hulsbergen, W.; Husemann, U.; Igonkina, O.; Ispiryan, M.; Jagla, T.; Jiang, C.; Kapitza, H.; Karabekyan, S.; Karpenko, N.; Keller, S.; Kessler, J.; Khasanov, F.; Kiryushin, Yu.; Kisel, I.; Klinkby, E.; Knöpfle, K. T.; Kolanoski, H.; Korpar, S.; Krauss, C.; Kreuzer, P.; Križan, P.; Krücker, D.; Kupper, S.; Kvaratskheliia, T.; Lanyov, A.; Lau, K.; Lewendel, B.; Lohse, T.; Lomonosov, B.; Männer, R.; Mankel, R.; Masciocchi, S.; Massa, I.; Matchikhilian, I.; Medin, G.; Medinnis, M.; Mevius, M.; Michetti, A.; Mikhailov, Yu.; Mizuk, R.; Muresan, R.; zur Nedden, M.; Negodaev, M.; Nörenberg, M.; Nowak, S.; Núñez Pardo de Vera, M. T.; Ouchrif, M.; Ould-Saada, F.; Padilla, C.; Peralta, D.; Pernack, R.; Pestotnik, R.; Petersen, B. AA.; Piccinini, M.; Pleier, M. A.; Poli, M.; Popov, V.; Pose, D.; Prystupa, S.; Pugatch, V.; Pylypchenko, Y.; Pyrlik, J.; Reeves, K.; Reßing, D.; Rick, H.; Riu, I.; Robmann, P.; Rostovtseva, I.; Rybnikov, V.; Sánchez, F.; Sbrizzi, A.; Schmelling, M.; Schmidt, B.; Schreiner, A.; Schröder, H.; Schwanke, U.; Schwartz, A. J.; Schwarz, A. S.; Schwenninger, B.; Schwingenheuer, B.; Sciacca, F.; Semprini-Cesari, N.; Shuvalov, S.; Silva, L.; Sözüer, L.; Solunin, S.; Somov, S.; Somov, A.; Spengler, J.; Spighi, R.; Spiridonov, A.; Stanovnik, A.; Starič, M.; Stegmann, C.; Subramania, H. S.; Symalla, M.; Tikhomirov, I.; Titov, M.; Tsakov, I.; Uwer, U.; van Eldik, C.; Vassiliev, Yu.; Villa, M.; Vitale, A.; Vukotic, I.; Wahlberg, H.; Walenta, A. H.; Walter, M.; Wang, J. J.; Wegener, D.; Werthenbach, U.; Wolters, H.; Wurth, R.; Wurz, A.; Xella-Hansen, S.; Zaitsev, Yu.; Zavertyaev, M.; Zeuner, T.; Zhelezov, A.; Zheng, Z.; Zimmermann, R.; Živko, T.; Zoccoli, A.

    2007-11-01

    A detailed description of an original method used to measure the luminosity accumulated by the HERA-B experiment for a data sample taken during the 2002-2003 HERA running period is reported. We show that, with this method, a total luminosity measurement can be achieved with a typical precision, including overall systematic uncertainties, at a level of 5% or better. We also report evidence for the detection of δ-rays generated in the target and comment on the possible use of such delta rays to measure luminosity.

  13. Achieving ultra-high temperatures with a resistive emitter array

    NASA Astrophysics Data System (ADS)

    Danielson, Tom; Franks, Greg; Holmes, Nicholas; LaVeigne, Joe; Matis, Greg; McHugh, Steve; Norton, Dennis; Vengel, Tony; Lannon, John; Goodwin, Scott

    2016-05-01

    The rapid development of very-large format infrared detector arrays has challenged the IR scene projector community to also develop larger-format infrared emitter arrays to support the testing of systems incorporating these detectors. In addition to larger formats, many scene projector users require much higher simulated temperatures than can be generated with current technology in order to fully evaluate the performance of their systems and associated processing algorithms. Under the Ultra High Temperature (UHT) development program, Santa Barbara Infrared Inc. (SBIR) is developing a new infrared scene projector architecture capable of producing both very large format (>1024 x 1024) resistive emitter arrays and improved emitter pixel technology capable of simulating very high apparent temperatures. During earlier phases of the program, SBIR demonstrated materials with MWIR apparent temperatures in excess of 1400 K. New emitter materials have subsequently been selected to produce pixels that achieve even higher apparent temperatures. Test results from pixels fabricated using the new material set will be presented and discussed. A 'scalable' Read In Integrated Circuit (RIIC) is also being developed under the same UHT program to drive the high temperature pixels. This RIIC will utilize through-silicon via (TSV) and Quilt Packaging (QP) technologies to allow seamless tiling of multiple chips to fabricate very large arrays, and thus overcome the yield limitations inherent in large-scale integrated circuits. Results of design verification testing of the completed RIIC will be presented and discussed.

  14. Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). I. Discovery of 15 Quasars and Bright Galaxies at 5.7 z > 6.9

    NASA Astrophysics Data System (ADS)

    Matsuoka, Yoshiki; Onoue, Masafusa; Kashikawa, Nobunari; Iwasawa, Kazushi; Strauss, Michael A.; Nagao, Tohru; Imanishi, Masatoshi; Niida, Mana; Toba, Yoshiki; Akiyama, Masayuki; Asami, Naoko; Bosch, James; Foucaud, Sébastien; Furusawa, Hisanori; Goto, Tomotsugu; Gunn, James E.; Harikane, Yuichi; Ikeda, Hiroyuki; Kawaguchi, Toshihiro; Kikuta, Satoshi; Komiyama, Yutaka; Lupton, Robert H.; Minezaki, Takeo; Miyazaki, Satoshi; Morokuma, Tomoki; Murayama, Hitoshi; Nishizawa, Atsushi J.; Ono, Yoshiaki; Ouchi, Masami; Price, Paul A.; Sameshima, Hiroaki; Silverman, John D.; Sugiyama, Naoshi; Tait, Philip J.; Takada, Masahiro; Takata, Tadafumi; Tanaka, Masayuki; Tang, Ji-Jia; Utsumi, Yousuke

    2016-09-01

    We report the discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9. This is the initial result from the Subaru High-z Exploration of Low-Luminosity Quasars project, which exploits the exquisite multiband imaging data produced by the Subaru Hyper Suprime-Cam (HSC) Strategic Program survey. The candidate selection is performed by combining several photometric approaches including a Bayesian probabilistic algorithm to reject stars and dwarfs. The spectroscopic identification was carried out with the Gran Telescopio Canarias and the Subaru Telescope for the first 80 deg2 of the survey footprint. The success rate of our photometric selection is quite high, approaching 100% at the brighter magnitudes (z AB < 23.5 mag). Our selection also recovered all the known high-z quasars on the HSC images. Among the 15 discovered objects, six are likely quasars, while the other six with interstellar absorption lines and in some cases narrow emission lines are likely bright Lyman-break galaxies. The remaining three objects have weak continua and very strong and narrow Lyα lines, which may be excited by ultraviolet light from both young stars and quasars. These results indicate that we are starting to see the steep rise of the luminosity function of z ≥ 6 galaxies, compared with that of quasars, at magnitudes fainter than M 1450 ˜ ‑22 mag or z AB ˜ 24 mag. Follow-up studies of the discovered objects as well as further survey observations are ongoing.

  15. Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). I. Discovery of 15 Quasars and Bright Galaxies at 5.7 < z < 6.9

    NASA Astrophysics Data System (ADS)

    Matsuoka, Yoshiki; Onoue, Masafusa; Kashikawa, Nobunari; Iwasawa, Kazushi; Strauss, Michael A.; Nagao, Tohru; Imanishi, Masatoshi; Niida, Mana; Toba, Yoshiki; Akiyama, Masayuki; Asami, Naoko; Bosch, James; Foucaud, Sébastien; Furusawa, Hisanori; Goto, Tomotsugu; Gunn, James E.; Harikane, Yuichi; Ikeda, Hiroyuki; Kawaguchi, Toshihiro; Kikuta, Satoshi; Komiyama, Yutaka; Lupton, Robert H.; Minezaki, Takeo; Miyazaki, Satoshi; Morokuma, Tomoki; Murayama, Hitoshi; Nishizawa, Atsushi J.; Ono, Yoshiaki; Ouchi, Masami; Price, Paul A.; Sameshima, Hiroaki; Silverman, John D.; Sugiyama, Naoshi; Tait, Philip J.; Takada, Masahiro; Takata, Tadafumi; Tanaka, Masayuki; Tang, Ji-Jia; Utsumi, Yousuke

    2016-09-01

    We report the discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9. This is the initial result from the Subaru High-z Exploration of Low-Luminosity Quasars project, which exploits the exquisite multiband imaging data produced by the Subaru Hyper Suprime-Cam (HSC) Strategic Program survey. The candidate selection is performed by combining several photometric approaches including a Bayesian probabilistic algorithm to reject stars and dwarfs. The spectroscopic identification was carried out with the Gran Telescopio Canarias and the Subaru Telescope for the first 80 deg2 of the survey footprint. The success rate of our photometric selection is quite high, approaching 100% at the brighter magnitudes (z AB < 23.5 mag). Our selection also recovered all the known high-z quasars on the HSC images. Among the 15 discovered objects, six are likely quasars, while the other six with interstellar absorption lines and in some cases narrow emission lines are likely bright Lyman-break galaxies. The remaining three objects have weak continua and very strong and narrow Lyα lines, which may be excited by ultraviolet light from both young stars and quasars. These results indicate that we are starting to see the steep rise of the luminosity function of z ≥ 6 galaxies, compared with that of quasars, at magnitudes fainter than M 1450 ˜ -22 mag or z AB ˜ 24 mag. Follow-up studies of the discovered objects as well as further survey observations are ongoing.

  16. The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor, Eruption and Aftermath of an Unusual Supergiant High-mass X-ray Binary

    NASA Astrophysics Data System (ADS)

    Villar, Victoria; Berger, Edo; Chornock, Ryan; Laskar, Tanmoy; Margutti, Raffaella; Brown, Peter J.

    2016-06-01

    We present high- and medium-resolution optical spectroscopy, optical/UV imaging and archival Chandra, Hubble and Spitzer observations of the intermediate luminosity optical transient (ILOT) SN 2010da, discovered in the nearby galaxy NGC 300 (d=1.86 Mpc). SN 2010da had a peak absolute magnitude of M ~ -10.4 mag, dimmer than other recent ILOTs and supernova impostors. We detect hydrogen Balmer, Paschen and Ca II emission lines in our high-resolution spectra, which indicate a dusty and complex circumstellar environment. Based on SN 2010da's light curve and multi-epoch SEDs, we conclude that the progenitor of SN 2010da is a ~10-12 Msol yellow supergiant possibly transitioning into a blue loop phase. Since the 2010 eruption, the star has brightened by a factor of ~5 and remains highly variable in the optical. SN 2010da is a unique ILOT which seems to stem from a different physical origin than red SN 2008S-like events and luminous blue variable outbursts. Furthermore, we detect SN 2010da in archival Swift observations as an ultraluminous X-ray source. We additionally attribute He II 4686 and coronal Fe emission in addition to a steady X-ray luminosity of ~10^{37} erg/s to the presence of a compact companion.

  17. Second-generation coil design of the Nb3Sn low-β quadrupole for the high luminosity LHC

    DOE PAGES

    Bermudez, S. Izquierdo; Ambrosio, G.; Ballarino, A.; Cavanna, E.; Bossert, R.; Cheng, D.; Dietderich, D.; Ferracin, P.; Ghosh, A.; Hagen, P.; et al

    2016-01-18

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with a finemore » tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this study, we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.« less

  18. Hiding from the Moonlight: Luminosity and Temperature Affect Activity of Asian Nocturnal Primates in a Highly Seasonal Forest

    PubMed Central

    Starr, Carly; Nekaris, K. A. I.; Leung, Luke

    2012-01-01

    The effect of moonlight and temperature on activity of slow lorises was previously little known and this knowledge might be useful for understanding many aspects of their behavioural ecology, and developing strategies to monitor and protect populations. In this study we aimed to determine if the activity of the pygmy loris (Nycticebus pygmaeus) is affected by ambient temperature and/or moonlight in a mixed deciduous forest. We radio-collared five females and five males in the Seima Protection Forest, Cambodia, in February to May, 2008 and January to March, 2009 and recorded their behaviour at 5 minutes intervals, totalling 2736 observations. We classified each observation as either inactive (sleeping or alert) or active behaviour (travel, feeding, grooming, or others). Moon luminosity (bright/dark) and ambient temperature were recorded for each observation. The response variable, activity, was binary (active or inactive), and a logit link function was used. Ambient temperature alone did not significantly affect mean activity. Although mean activity was significantly affected by moonlight, the interaction between moonlight and temperature was also significant: on bright nights, studied animals were increasingly more active with higher temperature; and on dark nights they were consistently active regardless of temperature. The most plausible explanation is that on bright cold nights the combined risk of being seen and attacked by predators and heat loss outweigh the benefit of active behaviours. PMID:22558461

  19. Hiding from the moonlight: luminosity and temperature affect activity of Asian nocturnal primates in a highly seasonal forest.

    PubMed

    Starr, Carly; Nekaris, K A I; Leung, Luke

    2012-01-01

    The effect of moonlight and temperature on activity of slow lorises was previously little known and this knowledge might be useful for understanding many aspects of their behavioural ecology, and developing strategies to monitor and protect populations. In this study we aimed to determine if the activity of the pygmy loris (Nycticebus pygmaeus) is affected by ambient temperature and/or moonlight in a mixed deciduous forest. We radio-collared five females and five males in the Seima Protection Forest, Cambodia, in February to May, 2008 and January to March, 2009 and recorded their behaviour at 5 minutes intervals, totalling 2736 observations. We classified each observation as either inactive (sleeping or alert) or active behaviour (travel, feeding, grooming, or others). Moon luminosity (bright/dark) and ambient temperature were recorded for each observation. The response variable, activity, was binary (active or inactive), and a logit link function was used. Ambient temperature alone did not significantly affect mean activity. Although mean activity was significantly affected by moonlight, the interaction between moonlight and temperature was also significant: on bright nights, studied animals were increasingly more active with higher temperature; and on dark nights they were consistently active regardless of temperature. The most plausible explanation is that on bright cold nights the combined risk of being seen and attacked by predators and heat loss outweigh the benefit of active behaviours.

  20. How to achieve high-level expression of microbial enzymes

    PubMed Central

    Liu, Long; Yang, Haiquan; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Du, Guocheng; Chen, Jian

    2013-01-01

    Microbial enzymes have been used in a large number of fields, such as chemical, agricultural and biopharmaceutical industries. The enzyme production rate and yield are the main factors to consider when choosing the appropriate expression system for the production of recombinant proteins. Recombinant enzymes have been expressed in bacteria (e.g., Escherichia coli, Bacillus and lactic acid bacteria), filamentous fungi (e.g., Aspergillus) and yeasts (e.g., Pichia pastoris). The favorable and very advantageous characteristics of these species have resulted in an increasing number of biotechnological applications. Bacterial hosts (e.g., E. coli) can be used to quickly and easily overexpress recombinant enzymes; however, bacterial systems cannot express very large proteins and proteins that require post-translational modifications. The main bacterial expression hosts, with the exception of lactic acid bacteria and filamentous fungi, can produce several toxins which are not compatible with the expression of recombinant enzymes in food and drugs. However, due to the multiplicity of the physiological impacts arising from high-level expression of genes encoding the enzymes and expression hosts, the goal of overproduction can hardly be achieved, and therefore, the yield of recombinant enzymes is limited. In this review, the recent strategies used for the high-level expression of microbial enzymes in the hosts mentioned above are summarized and the prospects are also discussed. We hope this review will contribute to the development of the enzyme-related research field. PMID:23686280

  1. High-Amplitude δ Scuti and SX Phoenicis Stars: The Effects of Chemical Composition on Pulsations and the Period-Luminosity Relation

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew; Basu, Sarbani; Demarque, Pierre

    2002-09-01

    We present a theoretical study of the radially pulsating δ Scuti and SX Phoenicis variables, concentrating on the blue straggler SX Phoenicis variables found in globular clusters. We have evolved a grid of stellar models with the metal abundance of the globular cluster M55, including models with alpha-enhanced metal abundances, and tested these models for radial pulsations observed in the high-amplitude δ Scuti and SX Phoenicis stars. Our grid includes models with globally enriched helium content to simulate the effects of stellar collisions and global mixing possible in blue stragglers. We find that global enrichment of helium strongly affects the temperature and luminosity of a given star, but the location of the instability strip blue edge and the slope of the period-luminosity (PL) relation are unchanged. This suggests that the PL relation is not affected by blue straggler formation if blue stragglers are fully mixed stellar mergers. Our blue edges and PL relations are in agreement with other theoretical determinations and also with the observational PL relation of M55, but they are not in agreement with the PL relation previously derived for high-amplitude δ Scuti stars in the field. Analysis of the double-mode variable, V41, suggests either that the star may not be pulsating in the first and second overtones as claimed or that normal stellar models may not be accurate models of blue straggler stars.

  2. The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor, Eruption, and Aftermath of a Peculiar Supergiant High-mass X-Ray Binary

    NASA Astrophysics Data System (ADS)

    Villar, V. A.; Berger, E.; Chornock, R.; Margutti, R.; Laskar, T.; Brown, P. J.; Blanchard, P. K.; Czekala, I.; Lunnan, R.; Reynolds, M. T.

    2016-10-01

    We present optical spectroscopy, ultraviolet-to-infrared imaging, and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 (d = 1.86 Mpc) spanning from ‑6 to +6 years relative to the time of outburst in 2010. Based on the light-curve and multi-epoch spectral energy distributions of SN 2010da, we conclude that the progenitor of SN 2010da is a ≈10–12 M ⊙ yellow supergiant possibly transitioning into a blue-loop phase. During outburst, SN 2010da had a peak absolute magnitude of M bol ≲ ‑10.4 mag, dimmer than other ILOTs and supernova impostors. We detect multi-component hydrogen Balmer, Paschen, and Ca ii emission lines in our high-resolution spectra, which indicate a dusty and complex circumstellar environment. Since the 2010 eruption, the star has brightened by a factor of ≈5 and remains highly variable in the optical. Furthermore, we detect SN 2010da in archival Swift and Chandra observations as an ultraluminous X-ray source (L X ≈ 6 × 1039 erg s‑1). We additionally attribute He ii 4686 Å and coronal Fe emission lines in addition to a steady X-ray luminosity of ≈1037 erg s‑1 to the presence of a compact companion.

  3. Comparison of the Level of Using Metacognitive Strategies during Study between High Achieving and Low Achieving Prospective Teachers

    ERIC Educational Resources Information Center

    Doganay, Ahmet; Demir, Ozden

    2011-01-01

    The main purpose of this study is to compare the level of using metacognitive strategies during study between high achieving and low achieving prospective classroom teachers. This study was designed as a mixed method study. Metacognitive Learning Strategies Scale developed by Namlu (2004) was used to measure the use of metacognitive strategies…

  4. Effects of Partner's Ability on the Achievement and Conceptual Organization of High-Achieving Fifth-Grade Students.

    ERIC Educational Resources Information Center

    Carter, Glenda; Jones, M. Gail; Rua, Melissa

    2003-01-01

    Investigates high-achieving fifth-grade students' achievement gains and conceptual reorganization on convection. Features an instructional sequence of three dyadic inquiry investigations related to convection currents as well as pre- and post-assessment consisting of a multiple-choice test, a card sorting task, construction of a concept map, and…

  5. Gender Differences in Attitudes toward Mathematics between Low-Achieving and High-Achieving Fifth Grade Elementary Students.

    ERIC Educational Resources Information Center

    Rathbone, A. Sue

    Possible gender differences in attitudes toward mathematics were studied between low-achieving and high-achieving fifth-grade students in selected elementary schools within a large, metropolitan area. The attitudes of pre-adolescent children at an intermediate grade level were assessed to determine the effects of rapidly emerging gender-related…

  6. STS atmospheric luminosities

    NASA Technical Reports Server (NTRS)

    Mende, S. B.

    1984-01-01

    During the STS-8 space shuttle mission special photographic and TV operations were carried out to record the properties of the spacecraft induced luminosities. One of these luminous phenomena is the quiescent vehicle glow which was photographed during the STS-8 mission with an image intensified photographic camera, with and without an objective grating. During the latter part of the mission the altitude of the shuttle was relatively low (120 n.m. = 222 km) and unprecedentedly high intensity of the glow was observed. The crew reported that the glow was easily visible to the naked eye. The proper orientation of the shuttle with respect to the velocity vector and the objective grating permitted the exposure of good objective spectrum of the glow in the visible region. From the results it is clear that the spectrum appears to be a continuum as observed by the image intensifier objective grating camera. Qualitative examination of the data shows that there is very tail little glow ion the wavelength range of 4300 to about 5000 angstroms. Above 5000 angstroms the glow becomes stronger towards the red and then it falls off towards higher wavelength and of the spectrum presumably because of the responsivity of the device.

  7. Achieving High Throughput for Data Transfer over ATM Networks

    NASA Technical Reports Server (NTRS)

    Johnson, Marjory J.; Townsend, Jeffrey N.

    1996-01-01

    File-transfer rates for ftp are often reported to be relatively slow, compared to the raw bandwidth available in emerging gigabit networks. While a major bottleneck is disk I/O, protocol issues impact performance as well. Ftp was developed and optimized for use over the TCP/IP protocol stack of the Internet. However, TCP has been shown to run inefficiently over ATM. In an effort to maximize network throughput, data-transfer protocols can be developed to run over UDP or directly over IP, rather than over TCP. If error-free transmission is required, techniques for achieving reliable transmission can be included as part of the transfer protocol. However, selected image-processing applications can tolerate a low level of errors in images that are transmitted over a network. In this paper we report on experimental work to develop a high-throughput protocol for unreliable data transfer over ATM networks. We attempt to maximize throughput by keeping the communications pipe full, but still keep packet loss under five percent. We use the Bay Area Gigabit Network Testbed as our experimental platform.

  8. The First Detection of [O IV] from an Ultraluminous X-ray Source with Spitzer. II. Evidence for High Luminosity in Holmberg II ULX

    NASA Technical Reports Server (NTRS)

    Berghea, C. T.; Dudik, R. P.; Weaver, K. A.; Kallman, T. R.

    2009-01-01

    This is the second of two papers examining Spitzer Infrared Spectrograph (IRS) observations of the ultraluminous X-ray source (ULX) in Holmberg II. Here we perform detailed photoionization modeling of they infrared lines. Our analysis suggests that the luminosity and morphology of the [O IV] 25.89 micron emission line is consistent with photoionization by the soft X-ray and far ultraviolet (FUV) radiation from the accretion disk of the binary system and inconsistent with narrow beaming. We show that the emission nebula is matter-bounded both in the line of sight direction and to the east, and probably radiation-bounded to the west. A bolometric luminosity in excess of 1040 erg per second would be needed to produce the measured [O IV] flux. We use modeling and previously published studies to conclude that shacks likely contribute very little, if at all, to the high excitation line fluxes observed in the Holmberg II ULX. Additionally, we find that the spectral type of the companion star has a surprisingly strong effect on they predicted strength of the [O IV] emission. This finding could explain the origin of [O IV] hi some starburst systems containing black hole binaries.

  9. The First Detection of [O IV] from an Ultraluminous X-ray Source with Spitzer. 2; Evidence for High Luminosity in Holmberg II ULX

    NASA Technical Reports Server (NTRS)

    Berghea, C. T.; Dudik, R. P.; Weaver, K. A.; Kallman, T. R.

    2009-01-01

    This is the second of two papers examining Spitzer Infrared Spectrograph (IRS) observations of the ultraluminous X-ray source (ULX) in Holmberg II. Here we perform detailed photoionization modeling of the infrared lines. Our analysis suggests that the luminosity and morphology of the [O IV] 25.89 micron emission line is consistent with photoionization by the soft X-ray and far ultraviolet (FUV) radiation from the accretion disk of the binary system and inconsistent with narrow beaming. We show that the emission nebula is matter-bounded both in the line of sight direction and to the east, and probably radiation-bounded to the west. A bolometric luminosity in excess of 10(exp 40) erg/s would be needed to produce the measured [O IV] flux. We use modeling and previously published studies to conclude that shocks likely contribute very little, if at all, to the high-excitation line fluxes observed in the Holmberg II ULX. Additionally, we find that the spectral type of the companion star has a surprisingly strong effect on the predicted strength of the [O IV] emission. This finding could explain the origin of [O IV] in some starburst systems containing black hole binaries.

  10. Student Perception of Academic Achievement Factors at High School

    ERIC Educational Resources Information Center

    Bahar, Mustafa

    2016-01-01

    Measuring the quality of the "product" is elemental in education, and most studies depend on observational data about student achievement factors, focusing overwhelmingly on quantitative data namely achievement scores, school data like attendance, facilities, expenditure class size, etc. But there is little evidence of learner…

  11. Learning Styles and High School Students' Chemistry Achievement

    ERIC Educational Resources Information Center

    Uzuntiryaki, Esen

    2007-01-01

    The aim of the present study was to investigate the effects of students' learning styles on their chemistry achievement, and whether matching between teaching and learning styles also affects students' chemistry achievement. Two hundred and sixty-five tenth-grade students enrolled in a chemistry course and seven chemistry teachers participated in…

  12. Does Recreational Computer Use Affect High School Achievement?

    ERIC Educational Resources Information Center

    Bowers, Alex J.; Berland, Matthew

    2013-01-01

    Historically, the relationship between student academic achievement and use of computers for fun and video gaming has been described from a multitude of perspectives, from positive, to negative, to neutral. However, recent research has indicated that computer use and video gaming may be positively associated with achievement, yet these studies…

  13. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    ERIC Educational Resources Information Center

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  14. Compensation of the long-range beam-beam interactions as a path towards new configurations for the high luminosity LHC

    NASA Astrophysics Data System (ADS)

    Fartoukh, Stéphane; Valishev, Alexander; Papaphilippou, Yannis; Shatilov, Dmitry

    2015-12-01

    Colliding bunch trains in a circular collider demands a certain crossing angle in order to separate the two beams transversely after the collision. The magnitude of this crossing angle is a complicated function of the bunch charge, the number of long-range beam-beam interactions, of β* and type of optics (flat or round), and possible compensation or additive effects between several low-β insertions in the ring depending on the orientation of the crossing plane at each interaction point. About 15 years ago, the use of current bearing wires was proposed at CERN in order to mitigate the long-range beam-beam effects [J. P. Koutchouk, CERN Report No. LHC-Project-Note 223, 2000], therefore offering the possibility to minimize the crossing angle with all the beneficial effects this might have: on the luminosity performance by reducing the need for crab-cavities or lowering their voltage, on the required aperture of the final focus magnets, on the strength of the orbit corrector involved in the crossing bumps, and finally on the heat load and radiation dose deposited in the final focus quadrupoles. In this paper, a semianalytical approach is developed for the compensation of the long-range beam-beam interactions with current wires. This reveals the possibility of achieving optimal correction through a careful adjustment of the aspect ratio of the β functions at the wire position. We consider the baseline luminosity upgrade plan of the Large Hadron Collider (HL-LHC project), and compare it to alternative scenarios, or so-called "configurations," where modifications are applied to optics, crossing angle, or orientation of the crossing plane in the two low-β insertions of the ring. For all these configurations, the beneficial impact of beam-beam compensation devices is then demonstrated on the tune footprint, the dynamical aperture, and/or the frequency map analysis of the nonlinear beam dynamics as the main figures of merit.

  15. Herschel-ATLAS Galaxy Counts and High-redshift Luminosity Functions: The Formation of Massive Early-type Galaxies

    NASA Astrophysics Data System (ADS)

    Lapi, A.; González-Nuevo, J.; Fan, L.; Bressan, A.; De Zotti, G.; Danese, L.; Negrello, M.; Dunne, L.; Eales, S.; Maddox, S.; Auld, R.; Baes, M.; Bonfield, D. G.; Buttiglione, S.; Cava, A.; Clements, D. L.; Cooray, A.; Dariush, A.; Dye, S.; Fritz, J.; Herranz, D.; Hopwood, R.; Ibar, E.; Ivison, R.; Jarvis, M. J.; Kaviraj, S.; López-Caniego, M.; Massardi, M.; Michałowski, M. J.; Pascale, E.; Pohlen, M.; Rigby, E.; Rodighiero, G.; Serjeant, S.; Smith, D. J. B.; Temi, P.; Wardlow, J.; van der Werf, P.

    2011-11-01

    Exploiting the Herschel Astrophysical Terahertz Large Area Survey Science Demonstration Phase survey data, we have determined the luminosity functions (LFs) at rest-frame wavelengths of 100 and 250 μm and at several redshifts z >~ 1, for bright submillimeter galaxies with star formation rates (SFRs) >~ 100 M ⊙ yr-1. We find that the evolution of the comoving LF is strong up to z ≈ 2.5, and slows down at higher redshifts. From the LFs and the information on halo masses inferred from clustering analysis, we derived an average relation between SFR and halo mass (and its scatter). We also infer that the timescale of the main episode of dust-enshrouded star formation in massive halos (M H >~ 3 × 1012 M ⊙) amounts to ~7 × 108 yr. Given the SFRs, which are in the range of 102-103 M ⊙ yr-1, this timescale implies final stellar masses of the order of 1011-1012 M ⊙. The corresponding stellar mass function matches the observed mass function of passively evolving galaxies at z >~ 1. The comparison of the statistics for submillimeter and UV-selected galaxies suggests that the dust-free, UV bright phase is >~ 102 times shorter than the submillimeter bright phase, implying that the dust must form soon after the onset of star formation. Using a single reference spectral energy distribution (SED; the one of the z ≈ 2.3 galaxy SMM J2135-0102), our simple physical model is able to reproduce not only the LFs at different redshifts >1 but also the counts at wavelengths ranging from 250 μm to ≈1 mm. Owing to the steepness of the counts and their relatively broad frequency range, this result suggests that the dispersion of submillimeter SEDs of z > 1 galaxies around the reference one is rather small. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  16. Achievement of Hispanic Students in American High Schools: Background Characteristics and Achievement. Contractor Report.

    ERIC Educational Resources Information Center

    Nielsen, Francois; Fernandez, Roberto M.

    Presenting data and analyses from the first wave of the study "High School and Beyond" (HS&B), a longitudinal study of United States high school sophomores and seniors, the report focuses on the composition of the Hispanic tenth and twelfth grade student population with respect to various characteristics; i.e., language use and proficiency, length…

  17. Preferences of High Achieving High School Students in Their Career Development

    ERIC Educational Resources Information Center

    Kim, Mihyeon

    2010-01-01

    The intent of this study was to identify the needs and preference of high-achieving high school students. In terms of career related programs in high school, students listed AP courses and mentoring as their preferred career-related programs. Also, students stated that career guidance by counselors, workshops or sessions, and tech prep were the…

  18. Threatened and Placed at Risk: High Achieving African American Males in Urban High Schools

    ERIC Educational Resources Information Center

    McGee, Ebony O.

    2013-01-01

    This study investigated the risk and protective factors of 11 high-achieving African American males attending 4 urban charter high schools in a Midwestern city to determine what factors account for their resilience and success in mathematics courses, and in high school more generally. This research was guided by a Phenomenological Variant of…

  19. Luminosity enhancements at SLAC

    SciTech Connect

    Coward, D.H.

    1984-04-01

    Several ideas are discussed that have been proposed to improve the luminosity at the SPEAR and PEP electron-positron storage rings and to insure good luminosity at the SLAC Linear Collider. There have been two proposals studied recently for SPEAR: a Microbeta insertion using Samarium Cobalt permanent magnets, and a Minibeta insertion using conventional quadrupole magnets. The notations Microbeta and minibeta used here are somewhat arbitrary since the front faces of the first quadrupole magnets for both insertions are at nearly the same distance from the interaction point.

  20. Luminosity measurements at hadron colliders

    SciTech Connect

    Papadimitriou, Vaia; /Fermilab

    2008-04-01

    In this paper we discuss luminosity measurements at Tevatron and HERA as well as plans for luminosity measurements at LHC. We discuss luminosity measurements using the luminosity detectors of the experiments as well as measurements by the machine. We address uncertainties of the measurements, challenges and lessons learned.

  1. The Effect of Music Participation on Mathematical Achievement and Overall Academic Achievement of High School Students

    ERIC Educational Resources Information Center

    Cox, H. A.; Stephens, L. J.

    2006-01-01

    A study was conducted on high school students, comparing those with some music credits to those with none. No statistically significant difference was found in their mean math grade point averages (GPA) or their mean cumulative GPAs. Students were then separated into two groups based on the number of music credits. Students who had earned at least…

  2. The search for low-luminosity high-mass X-ray binaries and the study of X-ray populations in the Galactic disk

    NASA Astrophysics Data System (ADS)

    Fornasini, Francesca; Tomsick, John; Bodaghee, Arash; Rahoui, Farid; Krivonos, Roman; Corral-Santana, Jesus; An, Hongjun; Bauer, Franz E.; Gotthelf, Eric V.; Stern, Daniel; NuSTAR Galactic Plane Survey Team

    2016-01-01

    High-mass X-ray binaries (HMXBs), which consist of a neutron star (NS) or black hole (BH) accreting material from a massive stellar companion, provide valuable insights into the evolution of massive stars and the merger rates of NS/NS, NS/BH, and BH/BH binaries whose gravitational wave signatures will soon be detectable by facilities such as Advanced-LIGO. INTEGRAL discoveries of new classes of lower-luminosity HMXBs, some highly obscured and some showing extreme transient activity, as well as the recent discovery of the very quiescent and only known Be-BH binary, have considerably changed our understanding of clumping in massive stellar winds and the relative importance of different binary evolutionary channels. In order to better characterize the low-luminosity HMXB population, we have performed a survey of a square degree region in the direction of the Norma spiral arm with Chandra and NuSTAR. These surveys, combined with optical and infrared spectroscopic follow-up of the counterparts of hard X-ray sources, have yielded three HMXB candidates to date. Future radial-velocity follow-up of these candidates, as well as other Be HMXB candidates from the NuSTAR serendipitous survey, will help determine whether these sources truly are HMXBs and, if so, constrain the mass of the compact object in these systems. If confirmed, these HMXB candidates could extend our measurement of the HMXB luminosity function by about two orders of magnitude and provide important constraints on massive binary evolutionary models. In addition, the colliding wind binaries and pulsar wind nebulae discovered in the Norma X-ray survey will help shed light on other aspects of massive stellar evolution and massive stellar remnants. Finally, these surveys provide the opportunity to compare the hard X-ray populations in the Galactic disk and the Galactic Center. While the dominant hard X-ray populations in both of these Galactic regions appear to be cataclysmic variables (CVs), those in the Norma

  3. Noise evaluation of silicon strip super-module with ABCN250 readout chips for the ATLAS detector upgrade at the High Luminosity LHC

    NASA Astrophysics Data System (ADS)

    Todome, K.; Jinnouchi, O.; Clark, A.; Barbier, G.; Cadoux, F.; Favre, Y.; Ferrere, D.; Gonzalez-Sevilla, S.; Iacobucci, G.; La Marra, D.; Perrin, E.; Weber, M.; Ikegami, Y.; Nakamura, K.; Takubo, Y.; Unno, Y.; Takashima, R.; Tojo, J.; Kono, T.; Hanagaki, K.; Hirose, M.; Homma, Y.; Sato, S.; Hara, K.; Sato, K.

    2016-09-01

    Toward High Luminosity LHC (HL-LHC), the whole ATLAS inner tracker will be replaced, including the semiconductor tracker (SCT) which is the silicon micro strip detector for tracking charged particles. In development of the SCT, integration of the detector is the important issue. One of the concepts of integration is the "super-module" in which individual modules are assembled to produce the SCT ladder. A super-module prototype has been developed to demonstrate its functionality. One of the concerns in integrating the super-modules is the electrical coupling between each module, because it may increase intrinsic noise of the system. To investigate the electrical performance of the prototype, the new Data Acquisition (DAQ) system has been developed by using SEABAS. The electric performance of the super-module prototype, especially the input noise and random noise hit rate, was investigated by using SEABAS system.

  4. "Brains before "Beauty"?" High Achieving Girls, School and Gender Identities

    ERIC Educational Resources Information Center

    Skelton, Christine; Francis, Becky; Read, Barbara

    2010-01-01

    In recent years educational policy on gender and achievement has concentrated on boys' underachievement, frequently comparing it with the academic success of girls. This has encouraged a perception of girls as the "winners" of the educational stakes and assumes that they no longer experience the kinds of gender inequalities identified in earlier…

  5. High-Achieving Middle Schools for Latino Students in Poverty

    ERIC Educational Resources Information Center

    Jesse, Dan; Davis, Alan; Pokorny, Nancy

    2004-01-01

    This study was conducted to examine the characteristics of middle schools in which Latino students from low-income families made substantial achievement gains. Nine schools in Texas were selected where Latino students had shown strong gains in the Texas Assessment of Academic Skills. Data from onsite interviews, focus groups, and documents were…

  6. Dominant Achievement Goals across Tracks in High School

    ERIC Educational Resources Information Center

    Scheltinga, Peter A. M.; Kuyper, Hans; Timmermans, Anneke C.; van der Werf, Greetje P. C.

    2016-01-01

    The dominant achievement goals (DAGs) of 7,008 students in the third grade of Dutch secondary education (US grade 9) were investigated, based on Elliot & McGregors' 2 × 2 framework (2001), in relation to track-level and motivational variables. We found the mastery-approach goal and the performance-approach goal, generally considered adaptive,…

  7. Success Despite Socioeconomics: A Case Study of a High-Achieving, High-Poverty School

    ERIC Educational Resources Information Center

    Tilley, Thomas Brent; Smith, Samuel J.; Claxton, Russell L.

    2012-01-01

    This case study of a high-achieving, high-poverty school describes the school's leadership, culture, and programs that contributed to its success. Data were collected from two surveys (the School Culture Survey and the Vanderbilt Assessment of Leadership in Education), observations at the school site, and interviews with school personnel. The…

  8. Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults

    ERIC Educational Resources Information Center

    Miller, Angie L.; Lambert, Amber D.; Speirs Neumeister, Kristie L.

    2012-01-01

    The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and…

  9. NLC Luminosity as a Function of Beam Parameters

    SciTech Connect

    Nosochkov, Yuri

    2002-06-06

    Realistic calculation of NLC luminosity has been performed using particle tracking in DIMAD and beam-beam simulations in GUINEA-PIG code for various values of beam emittance, energy and beta functions at the Interaction Point (IP). Results of the simulations are compared with analytic luminosity calculations. The optimum range of IP beta functions for high luminosity was identified.

  10. The Galactic Census of High- and Medium-mass Protostars. II. Luminosities and Evolutionary States of a Complete Sample of Dense Gas Clumps

    NASA Astrophysics Data System (ADS)

    Ma, Bo; Tan, Jonathan C.; Barnes, Peter J.

    2013-12-01

    The Census of High- and Medium-mass Protostars (CHaMP) is the first large-scale (280° < l < 300°, -4° < b < 2°), unbiased, subparsec resolution survey of Galactic molecular clumps and their embedded stars. Barnes et al. presented the source catalog of ~300 clumps based on HCO+(1-0) emission, used to estimate masses M. Here we use archival midinfrared-to-millimeter continuum data to construct spectral energy distributions. Fitting two-temperature gray-body models, we derive bolometric luminosities, L. We find that the clumps have 10 <~ L/L ⊙ <~ 106.5 and 0.1 <~ L/M/[L ⊙/M ⊙] <~ 103, consistent with a clump population spanning a range of instantaneous star-formation efficiencies from 0 to ~50%. We thus expect L/M to be a useful, strongly varying indicator of clump evolution during the star cluster formation process. We find correlations of the ratio of warm-to-cold component fluxes and of cold component temperature with L/M. We also find a near-linear relation between L/M and Spitzer-IRAC specific intensity (surface brightness); thus, this relation may also be useful as a star-formation efficiency indicator. The lower bound of the clump L/M distribution suggests that the star-formation efficiency per free-fall time is epsilonff < 0.2. We do not find strong correlations of L/M with mass surface density, velocity dispersion, or virial parameter. We find a linear relation between L and L_HCO^+(1{--0)}, although with large scatter for any given individual clump. Fitting together with extragalactic systems, the linear relation still holds, extending over 10 orders of magnitude in luminosity. The complete nature of the CHaMP survey over a several kiloparsec-scale region allows us to derive a measurement at an intermediate scale, bridging those of individual clumps and whole galaxies.

  11. A physical scenario for the high and low X-ray luminosity states in the transitional pulsar PSR J1023+0038

    NASA Astrophysics Data System (ADS)

    Campana, S.; Coti Zelati, F.; Papitto, A.; Rea, N.; Torres, D. F.; Baglio, M. C.; D'Avanzo, P.

    2016-10-01

    The binary system PSR J1023+0038 (J1023) hosts a neutron star and a low-mass companion. J1023 is the best studied transitional pulsar, alternating a faint eclipsing millisecond radio pulsar state to a brighter X-ray active state. At variance with other low-mass X-ray binaries, this active state reaches luminosities of only ~1034 erg s-1, showing strong, fast variability. In the active state, J1023 displays: i) a high state (LX ~ 7 × 1033 erg s-1, 0.3-80 keV) occurring ~80% of the time and during which X-ray pulsations at the neutron star spin period are detected (pulsed fraction ~ 8%); ii) a low state (LX ~ 1033 erg s-1) during which pulsations are not detected (≲ 3%); and iii) a flaring state during which sporadic flares occur in excess of ~ 1034 erg s-1, with no pulsation too. The transition between the high and the low states is very rapid, on a ~10 s timescale. Here we propose a plausible physical interpretation of the high and low states based on the (fast) transition among the propeller state and the radio pulsar state. We modelled the XMM-Newton spectra of the high, low and radio pulsar states, and found a good agreement with this physical picture.

  12. The MICE luminosity monitor

    NASA Astrophysics Data System (ADS)

    Dobbs, A.; Forrest, D.; Soler, F. J. P.

    2013-02-01

    The MICE experiment will provide the first measurement of ionisation cooling, a technique suitable for reducing the transverse emittance of a tertiary muon beam in a future neutrino factory accelerator facility. MICE is presently in the final stages of commissioning its beam line. The MICE luminosity monitor has proved an invaluable tool throughout this process, providing independent measurements of particle rate from the MICE target, normalisation for beam line detectors and verification of simulation codes.

  13. Relationship between High School Mathematical Achievement and Quantitative GPA

    ERIC Educational Resources Information Center

    Brown, Jennifer L.; Halpin, Glennelle; Halpin, Gerald

    2015-01-01

    The demand for STEM graduates has increased, but the number of incoming freshmen who declare a STEM major has remained stagnant. High school courses, such as calculus, can open or close the gate for students interested in careers in STEM. The purpose of this study was to determine if high school mathematics preparation was a significant…

  14. Relationships among Stress, Coping, and Mental Health in High-Achieving High School Students

    ERIC Educational Resources Information Center

    Suldo, Shannon M.; Shaunessy, Elizabeth; Hardesty, Robin

    2008-01-01

    This study investigates the relationships among stress, coping, and mental health in 139 students participating in an International Baccalaureate (IB) high school diploma program. Mental health was assessed using both positive indicators (life satisfaction, academic achievement, academic self-efficacy) and negative indicators (psychopathology) of…

  15. The Information Search Process of High-, Middle-, and Low-Achieving High School Seniors.

    ERIC Educational Resources Information Center

    Kuhlthau, Carol C.

    1989-01-01

    Presents a model of the information search process as a complex series of stages involving thoughts and feelings as well as actions. A study that sought to verify the model using high school seniors from three different achievement levels is described, and the implications for library instruction are discussed. (five references) (CLB)

  16. The Strengths of High-Achieving Black High School Students in a Racially Diverse Setting

    ERIC Educational Resources Information Center

    Marsh, Kris; Chaney, Cassandra; Jones, Derrick

    2012-01-01

    Robert Hill (1972) identified strengths of Black families: strong kinship bonds, strong work orientation, adaptability of family roles, high achievement orientation, and religious orientation. Some suggest these strengths sustain the physical, emotional, social, and spiritual needs of Blacks. This study used narratives and survey data from a…

  17. Examining Organizational Practices That Predict Persistence among High-Achieving Black Males in High School

    ERIC Educational Resources Information Center

    Anderson, Kenneth Alonzo

    2016-01-01

    Background/Context: This article summarizes an increasing trend of antideficit Black male research in mathematics and highlights opportunities to add to the research. A review of the literature shows that antideficit researchers often examine relationships between individual traits and persistence of high-achieving Black males in mathematics.…

  18. Japanese High School Entrance Examinations and Scholastic Achievement.

    ERIC Educational Resources Information Center

    Togashi, Yutaka

    1985-01-01

    The Japanese high school entrance examinations were examined in detail for social studies, mathematics, and science test items. Most items measured knowledge and comprehension rather than synthesis, analysis, or scientific thinking. Implications for middle school instruction were discussed. (GDC)

  19. Practically Perfect in Every Way: Can Reframing Perfectionism for High-Achieving Undergraduates Impact Academic Resilience?

    ERIC Educational Resources Information Center

    Dickinson, Mary J.; Dickinson, David A. G.

    2015-01-01

    This study focuses on a pan-disciplinary scheme that targeted high-achieving undergraduate students. Earlier research from the scheme argued that high achievers have discernibly different learning and personal development support needs. One of the most frequent self-reported challenges within this high-achieving group is perfectionism. This…

  20. Effect of primordial non-Gaussianities on the far-UV luminosity function of high-redshift galaxies: implications for cosmic reionization

    NASA Astrophysics Data System (ADS)

    Chevallard, Jacopo; Silk, Joseph; Nishimichi, Takahiro; Habouzit, Melanie; Mamon, Gary A.; Peirani, Sébastien

    2015-01-01

    Understanding how the intergalactic medium (IGM) was reionized at z ≳ 6 is one of the big challenges of current high-redshift astronomy. It requires modelling the collapse of the first astrophysical objects (Pop III stars, first galaxies) and their interaction with the IGM, while at the same time pushing current observational facilities to their limits. The observational and theoretical progress of the last few years have led to the emergence of a coherent picture in which the budget of hydrogen-ionizing photons is dominated by low-mass star-forming galaxies, with little contribution from Pop III stars and quasars. The reionization history of the Universe therefore critically depends on the number density of low-mass galaxies at high redshift. In this work, we explore how changes in the cosmological model, and in particular in the statistical properties of initial density fluctuations, affect the formation of early galaxies. Following Habouzit et al. (2014), we run five different N-body simulations with Gaussian and (scale-dependent) non-Gaussian initial conditions, all consistent with Planck constraints. By appealing to a phenomenological galaxy formation model and to a population synthesis code, we compute the far-UV galaxy luminosity function down to MFUV = -14 at redshift 7 ≤ z ≤ 15. We find that models with strong primordial non-Gaussianities on ≲ Mpc scales show a far-UV luminosity function significantly enhanced (up to a factor of 3 at z = 14) in low-mass galaxies. We adopt a reionization model calibrated from state-of-the-art hydrodynamical simulations and show that such scale-dependent non-Gaussianities leave a clear imprint on the Universe reionization history and electron Thomson scattering optical depth τe. Although current uncertainties in the physics of reionization and on the determination of τe still dominate the signatures of non-Gaussianities, our results suggest that τe could ultimately be used to constrain the statistical properties

  1. The First Detection of [O IV] from an Ultraluminous X-ray Source with Spitzer: Evidence of High Unbeamed Luminosity in Holmberg II ULX

    NASA Technical Reports Server (NTRS)

    Berghea, C. T.; Dudik, R. P.; Weaver, K. A.; Kallman, T. R.

    2008-01-01

    We present the first Spitzer Infrared Spectrograph (IRS) observations of the [O IV] 25.89 micron emission line detected from the ultraluminous X-ray source (ULX) in Holmberg II. This line is a well established signature of high excitation, usually associated with AGN. Its detection suggests that the ULX has a strong impact on the surrounding gas. A Spitzer high resolution spectral map shows that the [O IV] is coincident with the X-ray position of the Holmberg II ULX. We find that the luminosity and the morphology of the line emission is consistent with photoionization by the soft X-ray and far ultraviolet (FUV) radiation from the accretion disk of the binary system and inconsistent with narrow beaming. We show that the emission nebula is radiation bounded both in the line of sight direction and to the west, and probably matter bounded to the east. Evidence for a massive black hole (BH) in this ULX is mounting. Detailed photoionization models favor an intermediate mass black hole of at least 85 Solar Mass as the ionization source for the [OIV] emission. We find that the spectral type of the companion star strongly affects the expected strength of the [O IV] emission. This finding could explain the origin of [O IV] in some starburst galaxies containing black hole binaries.

  2. Achieving high-value cardiac imaging: challenges and opportunities.

    PubMed

    Wiener, David H

    2014-01-01

    Cardiac imaging is under intense scrutiny as a contributor to health care costs, with multiple initiatives under way to reduce and eliminate inappropriate testing. Appropriate use criteria are valuable guides to selecting imaging studies but until recently have focused on the test rather than the patient. Patient-centered means are needed to define the true value of imaging for patients in specific clinical situations. This article provides a definition of high-value cardiac imaging. A paradigm to judge the efficacy of echocardiography in the absence of randomized controlled trials is presented. Candidate clinical scenarios are proposed in which echocardiography constitutes high-value imaging, as well as stratagems to increase the likelihood that high-value cardiac imaging takes place in those circumstances.

  3. Achieving high CRI from warm to super white

    NASA Astrophysics Data System (ADS)

    Bailey, Edward; Tormey, Ellen S.

    2007-09-01

    Light sources which produce a high color rendering index (CRI) have many applications in the lighting industry today. High color rendering accents the rich color which abounds in nature, interior design, theatrical costumes and props, clothing and fabric, jewelry, and machine vision applications. Multi-wavelength LED sources can pump phosphors at multiple stokes shift emission regimes and when combined with selected direct emission sources can allow for greater flexibility in the production of warm-white and cool white light of specialty interest. Unique solutions to R8 and R14 CRI >95 at 2850K, 4750K, 5250K, and 6750K presented.

  4. Community Schools Seek to Improve High School Achievement, College Readiness

    ERIC Educational Resources Information Center

    Gilroy, Marilyn

    2011-01-01

    The Coalition for Community Schools, an alliance of more than 150 national, state, and local organizations, is bringing public schools in partnership with community resources to improve student success. While that might seem like an abstract idea, it has very concrete goals, such as boosting high school graduation rates and college readiness.…

  5. High-Achieving Schools Put Equity Front and Center

    ERIC Educational Resources Information Center

    Gleason, Sonia Caus; Gerzon, Nancy

    2014-01-01

    How does professional learning look and feel in high-poverty schools where every student makes at least one year's worth of progress every year? How do schools and leaders put all the varied components of professional learning together so that they support all students learning every day? What professional learning grounds and sustains…

  6. Organizational Citizenship of Faculty and Achievement of High School Students

    ERIC Educational Resources Information Center

    DiPaola, Michael F.; Hoy, Wayne K.

    2005-01-01

    All successful organizations, including successful high schools, have employees who go beyond their formal job responsibilities and freely give of their time and energy to succeed. Organ was the first to use the phrase "organizational citizenship behavior" (OCB) to denote organizationally beneficial behavior of workers that was not prescribed but…

  7. Academic Dishonesty among Gifted and High-Achieving Students

    ERIC Educational Resources Information Center

    Geddes, Kimberly A.

    2011-01-01

    Gifted high school students are essentially absent in the research concerning academic integrity; however, over the past few years, educators of gifted students have noticed an increase in the occurrences of academic dishonesty among students in gifted classrooms (Abilock, 2009). This research may be analyzed to provide some insight into the…

  8. Vocational Interests of Intellectually Gifted and Highly Achieving Young Adults

    ERIC Educational Resources Information Center

    Vock, Miriam; Koller, Olaf; Nagy, Gabriel

    2013-01-01

    Background: Vocational interests play a central role in the vocational decision-making process and are decisive for the later job satisfaction and vocational success. Based on Ackerman's (1996) notion of "trait complexes," specific interest profiles of gifted high-school graduates can be expected. Aims: Vocational interests of gifted and highly…

  9. Common Core and America's High-Achieving Students

    ERIC Educational Resources Information Center

    Plucker, Jonathan A.

    2015-01-01

    While the merit and politics of the Common Core State Standards (CCSS) have been much debated and discussed, one topic has been virtually ignored: What do the standards portend for America's high-ability students? This brief addresses that question and provides guidance for CCSS-implementing districts and schools as they seek to help these…

  10. The Relationship between Highly Qualified Teachers and Student Academic Achievement

    ERIC Educational Resources Information Center

    Macken, Sherry Lou

    2013-01-01

    This study examined the relationship between the percentage of highly qualified teachers and standardized measures of student proficiency in the core academic subjects of mathematics, reading, science, social studies, and writing. Signed into law in January of 2002 by President George W. Bush, the No Child Left Behind (NCLB) Act requires teachers…

  11. More High-Achieving Students Are Choosing Community Colleges First

    ERIC Educational Resources Information Center

    Pluviose, David

    2008-01-01

    Certainly, "Tonight Show" host Jay Leno has nurtured the perception that community colleges are a punishment for underperforming high school students by joking that community colleges aren't "real colleges." This article shows that this perception belies the reality that contemporary community colleges serve students seeking trade skills but also…

  12. Park View High School: A World of Achievement

    ERIC Educational Resources Information Center

    Principal Leadership, 2010

    2010-01-01

    Entering the lobby of Park View High School in Sterling, VA, is like entering another world. The diversity in the student body is reflected in flags from 63 of the 80 countries that are represented in the student population, and in a special project for Hispanic Heritage Month, which covers the walls of an entire hallway. The school walls,…

  13. Testing Theories of Learning: Effects on High School Achievement.

    ERIC Educational Resources Information Center

    Keith, Timothy Z.; Cool, Valerie A.

    Theories of school learning consistently point to variables such as ability, time (e.g., homework), quality of instruction, motivation, and academic coursework as important influences on learning. In this study, path analysis was used to test the direct and indirect effects of these variables on high school learning, with learning measured by both…

  14. Gender, Student Motivation and Academic Achievement in a Midsized Wisconsin High School

    ERIC Educational Resources Information Center

    Lutzke, Steven Ronald

    2013-01-01

    This mixed-methods study investigated relationships among gender, academic motivation and achievement in a mid-sized Wisconsin high school. A questionnaire was developed that focused on perceived ability, achievement motives and achievement goals. Interviews with teachers focused on relationships among academic motivation and gender achievement.…

  15. Impact of learning orientation on African American children's attitudes toward high-achieving peers.

    PubMed

    Marryshow, Derrick; Hurley, Eric A; Allen, Brenda A; Tyler, Kenneth M; Boykin, A Wade

    2005-01-01

    This study examined Ogbu's widely accepted thesis that African American students reject high academic achievement because they perceive its limited utility in a world where their upward mobility is constrained by racial discrimination. Boykin's psychosocial integrity model contends that Black students value high achievement but that discrepancies between their formative cultural experiences and those imposed in school lead them to reject the modes of achievement available in classrooms. Ninety Black children completed a measure of attitudes toward students who achieve via mainstream or African American cultural values. Participants rejected the mainstream achievers and embraced the African American cultural achievers. Moreover, they expected their teachers to embrace the mainstream achievers and reject those who achieved through high-verve behavior. Results suggest that Boykin's thesis is a needed refinement to Ogbu's ideas. They indicate that Black children may reject not high achievement but some of the mainstream cultural values and behaviors on which success in mainstream classrooms is made contingent.

  16. Principals’ Perception of Influence on Factors Affecting Student Achievement in Low- and High-Achieving Urban High Schools

    ERIC Educational Resources Information Center

    Bloom, Collette M.; Owens, Emiel W.

    2013-01-01

    The purpose of the study was to compare and contrast influences principals have on staffing, curriculum issues, and discipline policies in high- and low-performing urban high schools. The data for the present study were drawn from the first year follow up of the Educational Longitudinal Survey of 2002-2004 (ELS: 02), administered by the National…

  17. Achievement of a 920-MHz High Resolution NMR

    NASA Astrophysics Data System (ADS)

    Hashi, Kenjiro; Shimizu, Tadashi; Goto, Atsushi; Kiyoshi, Tsukasa; Matsumoto, Shinji; Wada, Hitoshi; Fujito, Teruaki; Hasegawa, Ken-ichi; Yoshikawa, Masatoshi; Miki, Takashi; Ito, Satoshi; Hamada, Mamoru; Hayashi, Seiji

    2002-06-01

    We have developed a 920-MHz NMR system and performed the proton NMR measurement of H 2O and ethylbenzene using the superconducting magnet operating at 21.6 T (920 MHz for proton), which is the highest field produced by a superconducting NMR magnet in the persistent mode. From the NMR measurements, it is verified that both homogeneity and stability of the magnet have a specification sufficient for a high resolution NMR.

  18. Telescoping Solar Array Concept for Achieving High Packaging Efficiency

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

    2015-01-01

    Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

  19. Efforts toward achieving an unmanned, high-altitude LTA platform

    SciTech Connect

    Onda, Masahiko; Ford, M.L.

    1996-10-01

    The modern demands for an unmanned aerospace platform, capable of long-duration stationkeeping at high-altitudes, are well-known. Satellites, balloons, and aircraft have traditionally served in the role of platform, facilitating tasks ranging from telecommunications to deep-space astronomy. However, limitations on the performance and flexibility of these systems, as well as the intrinsically high-cost of satellite construction, operation, and repair, warrants development of a supplemental technology for the platform. Much has been written in the literature on the possible advantages of a lighter-than-air (LTA) platform, if such an LTA could be constructed. Potential applications include remote sensing, environmental monitoring, mobile communications, space and polar observations, cargo delivery, military reconnaissance, and others. At present, conventional LTA`s are not capable of serving in the manner specified. Within this context, a research program known as HALROP (High Altitude Long Range Observational Platform) is currently underway. The goal is to create a stratospheric platform, possibly in the form of a next generation LTA vehicle. The authors present a qualitative review of their efforts, focusing on milestones in the HALROP Program. 12 refs., 6 figs., 2 tabs.

  20. Achieving High Reliability Operations Through Multi-Program Integration

    SciTech Connect

    Holly M. Ashley; Ronald K. Farris; Robert E. Richards

    2009-04-01

    Over the last 20 years the Idaho National Laboratory (INL) has adopted a number of operations and safety-related programs which has each periodically taken its turn in the limelight. As new programs have come along there has been natural competition for resources, focus and commitment. In the last few years, the INL has made real progress in integrating all these programs and are starting to realize important synergies. Contributing to this integration are both collaborative individuals and an emerging shared vision and goal of the INL fully maturing in its high reliability operations. This goal is so powerful because the concept of high reliability operations (and the resulting organizations) is a masterful amalgam and orchestrator of the best of all the participating programs (i.e. conduct of operations, behavior based safety, human performance, voluntary protection, quality assurance, and integrated safety management). This paper is a brief recounting of the lessons learned, thus far, at the INL in bringing previously competing programs into harmony under the goal (umbrella) of seeking to perform regularly as a high reliability organization. In addition to a brief diagram-illustrated historical review, the authors will share the INL’s primary successes (things already effectively stopped or started) and the gaps yet to be bridged.

  1. Advancing Minority High Achievement: National Trends and Promising Programs and Practices. A Report Prepared for the National Task Force on Minority High Achievement, the College Board.

    ERIC Educational Resources Information Center

    Borman, Geoffrey D.; Stringfield, Sam; Rachuba, Laura

    This report documents recent national progress in advancing the achievements of elementary-aged minority children, the potential for replicable whole-school reform designs to contribute to this advancement, and the individual, classroom, and school characteristics that distinguish those minority students who attain high levels of achievement. The…

  2. SDSS J013127.34–032100.1: A NEWLY DISCOVERED RADIO-LOUD QUASAR AT z = 5.18 WITH EXTREMELY HIGH LUMINOSITY

    SciTech Connect

    Yi, Wei-Min; Bai, Jin-Ming; Zhang, Ju-jia; Wang, Fang; Wang, Jian-Guo; Fan, Yu-Feng; Chang, Liang; Wang, Chuan-Jun; Lun, Bao-Li; Wang, Feige; Wu, Xue-Bing; Yang, Jinyi; Ho, Luis C.; Zuo, Wenwen; Yang, Qian; Ai, Yanli; Fan, Xiaohui; Brandt, William N.; Kim, Minjin; Wang, Ran; and others

    2014-11-10

    Very few of the z > 5 quasars discovered to date have been radio-loud, with radio-to-optical flux ratios (radio-loudness parameters) higher than 10. Here we report the discovery of an optically luminous radio-loud quasar, SDSS J013127.34–032100.1 (J0131–0321 in short), at z = 5.18 ± 0.01 using the Lijiang 2.4 m and Magellan telescopes. J0131–0321 has a spectral energy distribution consistent with that of radio-loud quasars. With an i-band magnitude of 18.47 and a radio flux density of 33 mJy, its radio-loudness parameter is ∼100. The optical and near-infrared spectra taken by Magellan enable us to estimate its bolometric luminosity to be L {sub bol} ∼ 1.1 × 10{sup 48} erg s{sup –1}, approximately 4.5 times greater than that of the most distant quasar known to date. The black hole mass of J0131–0321 is estimated to be 2.7 × 10{sup 9} M {sub ☉}, with an uncertainty up to 0.4 dex. Detailed physical properties of this high-redshift, radio-loud, potentially super-Eddington quasar can be probed in the future with more dedicated and intensive follow-up observations using multi-wavelength facilities.

  3. SDSS J013127.34-032100.1: A Newly Discovered Radio-loud Quasar at z = 5.18 with Extremely High Luminosity

    NASA Astrophysics Data System (ADS)

    Yi, Wei-Min; Wang, Feige; Wu, Xue-Bing; Yang, Jinyi; Bai, Jin-Ming; Fan, Xiaohui; Brandt, William N.; Ho, Luis C.; Zuo, Wenwen; Kim, Minjin; Wang, Ran; Yang, Qian; Zhang, Ju-jia; Wang, Fang; Wang, Jian-Guo; Ai, Yanli; Fan, Yu-Feng; Chang, Liang; Wang, Chuan-Jun; Lun, Bao-Li; Xin, Yu-Xin

    2014-11-01

    Very few of the z > 5 quasars discovered to date have been radio-loud, with radio-to-optical flux ratios (radio-loudness parameters) higher than 10. Here we report the discovery of an optically luminous radio-loud quasar, SDSS J013127.34-032100.1 (J0131-0321 in short), at z = 5.18 ± 0.01 using the Lijiang 2.4 m and Magellan telescopes. J0131-0321 has a spectral energy distribution consistent with that of radio-loud quasars. With an i-band magnitude of 18.47 and a radio flux density of 33 mJy, its radio-loudness parameter is ~100. The optical and near-infrared spectra taken by Magellan enable us to estimate its bolometric luminosity to be L bol ~ 1.1 × 1048 erg s-1, approximately 4.5 times greater than that of the most distant quasar known to date. The black hole mass of J0131-0321 is estimated to be 2.7 × 109 M ⊙, with an uncertainty up to 0.4 dex. Detailed physical properties of this high-redshift, radio-loud, potentially super-Eddington quasar can be probed in the future with more dedicated and intensive follow-up observations using multi-wavelength facilities.

  4. Mechanical qualification of the support structure for MQXF, the Nb3Sn low-β quadrupole for the high luminosity LHC

    DOE PAGES

    Juchno, M.; Ambrosio, G.; Anerella, M.; Bajas, H.; Bajko, M.; Bourcey, N.; Cheng, D. W.; Felice, H.; Ferracin, P.; Grosclaude, P.; et al

    2016-01-26

    Within the scope of the High Luminosity LHC project, the collaboration between CERN and U.S. LARP is developing new low-β quadrupoles using the Nb3Sn superconducting technology for the upgrade of the LHC interaction regions. The magnet support structure of the first short model was designed and two units were fabricated and tested at CERN and at LBNL. The structure provides the preload to the collars-coils subassembly by an arrangement of outer aluminum shells pre-tensioned with water-pressurized bladders. For the mechanical qualification of the structure and the assembly procedure, superconducting coils were replaced with solid aluminum “dummy coils”, the structure wasmore » preloaded at room temperature, and then cooled-down to 77 K. Mechanical behavior of the magnet structure was monitored with the use of strain gauges installed on the aluminum shells, the dummy coils and the axial preload system. As a result, this paper reports on the outcome of the assembly and the cool-down tests with dummy coils, which were performed at CERN and at LBNL, and presents the strain gauge measurements compared to the 3D finite element model predictions.« less

  5. SMA observations on faint submillimeter galaxies with S {sub 850} < 2 mJy: Ultra dusty low-luminosity galaxies at high redshift

    SciTech Connect

    Chen, Chian-Chou; Cowie, Lennox L.; Barger, Amy J.; Williams, Jonathan P.; Wang, Wei-Hao

    2014-07-01

    We obtained Submillimeter Array (SMA) observations of eight faint (intrinsic 850 μm fluxes < 2 mJy) submillimeter galaxies (SMGs) discovered in SCUBA images of the massive lensing cluster fields A370, A2390, and A1689 and detected five. In total, we obtain five SMA detections, all of which have de-lensed fluxes <1 mJy with estimated total infrared luminosities 10{sup 10}-10{sup 12} L {sub ☉}, comparable to luminous infrared galaxies and normal star-forming galaxies. Based on the latest number counts, these galaxies contribute ∼70% of the 850 μm extragalactic background light and represent the dominant star-forming galaxy population in the dusty universe. However, only 40{sub −16}{sup +30}% of our faint SMGs would be detected in deep optical or near-infrared surveys, which suggests many of these sources are at high redshifts (z ≳ 3) or extremely dusty, and they are not included in current star formation history estimates.

  6. Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    NASA Astrophysics Data System (ADS)

    Sugano, Michinaka; Ballarino, Amalia; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2016-02-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young’s modulus of MgB2 filaments in wires with a practical level of critical current. The Young’s moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young’s modulus of the few-micron-thick Nb-Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young’s moduli of the in situ and ex situ MgB2 wires were in the range of 76-97 GPa and no distinct difference depending on the fabrication process was found.

  7. The Relationship between Parental Involvement and Student Achievement in a Rural Florida High School

    ERIC Educational Resources Information Center

    Jackson, Willie A.

    2011-01-01

    Parental involvement is viewed as critical to the development of effective schools and student achievement. The relationship between parental involvement and achievement test scores at a rural high school in Florida was not known. This high school has not met the state standards as determined by the Florida Comprehensive Achievement Test (FCAT)…

  8. High Achievement in Mathematics Education in India: A Report from Mumbai

    ERIC Educational Resources Information Center

    Raman, Manya

    2010-01-01

    This paper reports a study aimed at characterizing the conditions that lead to high achievement in mathematics in India. The study involved eight schools in the greater Mumbai region. The main result of the study is that the notion of high achievement itself is problematic, as reflected in the reports about mathematics achievement within and…

  9. An improved method of constructing binned luminosity functions

    NASA Astrophysics Data System (ADS)

    Page, M. J.; Carrera, F. J.

    2000-01-01

    We show that binned differential luminosity functions constructed using the 1/Va method have a significant systematic error for objects close to the flux limit(s) of their parent sample. This is particularly noticeable when luminosity functions are produced for a number of different redshift ranges as is common in the study of AGN or galaxy evolution. We present a simple method of constructing a binned luminosity function which overcomes this problem and has a number of other advantages over the traditional 1/Va method. We also describe a practical method for comparing binned and model luminosity functions, by calculating the expectation values of the binned luminosity function from the model. Binned luminosity functions produced by the two methods are compared for simulated data and for the Large Bright QSO Survey (LBQS). It is shown that the 1/Va method produces a very misleading picture of evolution in the LBQS. The binned luminosity function of the LBQS is then compared with a model two-power-law luminosity function undergoing pure luminosity evolution from Boyle et al. The comparison is made using a model luminosity function averaged over each redshift shell, and using the expectation values for the binned luminosity function calculated from the model. The luminosity function averaged in each redshift shell gives a misleading impression that the model over predicts the number of QSOs at low luminosity even for 1.0< z<1.5, when model and data are consistent. The expectation values show that there are significant differences between model and data: the model overpredicts the number of low luminosity sources at both low and high redshift. The luminosity function does not appear to steepen relative to the model as redshift increases.

  10. Predicting delay in reading achievement in a highly transparent language.

    PubMed

    Holopainen, L; Ahonen, T; Lyytinen, H

    2001-01-01

    A random sample of 91 preschool children was assessed prior to receiving formal reading instruction. Verbal and nonverbal measures were used as predictors for the time of instruction required to accurately decode pseudowords in the highly orthographically regular Finnish language. After 2 years, participants were divided into four groups depending on the duration of instruction they had required to reach 90 % accuracy in their reading of pseudowords. Participants were classified as precocious decoders (PD), who could read at school entry; early decoders (ED), who learned to read within the first 4 months of Grade 1; ordinary decoders (OD), who learned to read within 9 months; and late decoders (LD), who failed to reach the criterion after 18 months of reading instruction at Grade 2. Phonological awareness played a significant role only in differentiating PD from ED and OD. However, phonological awareness failed to predict the delayed learning process of LD. LD differed from all other groups in visual analogical reasoning in an analysis not containing phonological awareness measures. Letter knowledge and visual analogical reasoning explained above 90% of the PD-LD difference. Preschool composite (objects, colors, and digits) naming speed measures best predicted reading fluency at the end of Grade 2. The supportive role of orthographic knowledge in phonological awareness, the role of visual analogical reasoning, and the inability of phonological measures to discriminate late decoders are discussed.

  11. Achieving High-Frequency Optical Control of Synaptic Transmission

    PubMed Central

    Jackman, Skyler L.; Beneduce, Brandon M.; Drew, Iain R.

    2014-01-01

    The optogenetic tool channelrhodopsin-2 (ChR2) is widely used to excite neurons to study neural circuits. Previous optogenetic studies of synapses suggest that light-evoked synaptic responses often exhibit artificial synaptic depression, which has been attributed to either the inability of ChR2 to reliably fire presynaptic axons or to ChR2 elevating the probability of release by depolarizing presynaptic boutons. Here, we compare light-evoked and electrically evoked synaptic responses for high-frequency stimulation at three synapses in the mouse brain. At synapses from Purkinje cells to deep cerebellar nuclei neurons (PC→DCN), light- and electrically evoked synaptic currents were remarkably similar for ChR2 expressed transgenically or with adeno-associated virus (AAV) expression vectors. For hippocampal CA3→CA1 synapses, AAV expression vectors of serotype 1, 5, and 8 led to light-evoked synaptic currents that depressed much more than electrically evoked currents, even though ChR2 could fire axons reliably at up to 50 Hz. The disparity between optical and electrical stimulation was eliminated when ChR2 was expressed transgenically or with AAV9. For cerebellar granule cell to stellate cell (grc→SC) synapses, AAV1 also led to artificial synaptic depression and AAV9 provided superior performance. Artificial synaptic depression also occurred when stimulating over presynaptic boutons, rather than axons, at CA3→CA1 synapses, but not at PC→DCN synapses. These findings indicate that ChR2 expression methods and light stimulation techniques influence synaptic responses in a neuron-specific manner. They also identify pitfalls associated with using ChR2 to study synapses and suggest an approach that allows optogenetics to be applied in a manner that helps to avoid potential complications. PMID:24872574

  12. The high-mass end of the red sequence at z ˜ 0.55 from SDSS-III/BOSS: completeness, bimodality and luminosity function

    NASA Astrophysics Data System (ADS)

    Montero-Dorta, Antonio D.; Bolton, Adam S.; Brownstein, Joel R.; Swanson, Molly; Dawson, Kyle; Prada, Francisco; Eisenstein, Daniel; Maraston, Claudia; Thomas, Daniel; Comparat, Johan; Chuang, Chia-Hsun; McBride, Cameron K.; Favole, Ginevra; Guo, Hong; Rodríguez-Torres, Sergio; Schneider, Donald P.

    2016-09-01

    We have developed an analytical method based on forward-modelling techniques to characterize the high-mass end of the red sequence (RS) galaxy population at redshift z ˜ 0.55, from the DR10 BOSS (Baryon Oscillation Spectroscopic Survey) CMASS spectroscopic sample, which comprises ˜600 000 galaxies. The method, which follows an unbinned maximum likelihood approach, allows the deconvolution of the intrinsic CMASS colour-colour-magnitude distributions from photometric errors and selection effects. This procedure requires modelling the covariance matrix for the i-band magnitude, g - r colour and r - i colour using Stripe 82 multi-epoch data. Our results indicate that the error-deconvolved intrinsic RS distribution is consistent, within the photometric uncertainties, with a single point (<0.05 mag) in the colour-colour plane at fixed magnitude, for a narrow redshift slice. We have computed the high-mass end (0.55Mi ≲ -22) of the 0.55i-band RS luminosity function (RS LF) in several redshift slices within the redshift range 0.52 < z < 0.63. In this narrow redshift range, the evolution of the RS LF is consistent, within the uncertainties in the modelling, with a passively evolving model with Φ* = (7.248 ± 0.204) × 10- 4 Mpc-3 mag-1, fading at a rate of 1.5 ± 0.4 mag per unit redshift. We report RS completeness as a function of magnitude and redshift in the CMASS sample, which will facilitate a variety of galaxy-evolution and clustering studies using BOSS. Our forward-modelling method lays the foundations for future studies using other dark-energy surveys like the Extended Baryon Oscillation Spectroscopic Survey or the Dark Energy Spectroscopic Instrument, which are affected by the same type of photometric blurring/selection effects.

  13. The Chinese High School Student's Stress in the School and Academic Achievement

    ERIC Educational Resources Information Center

    Liu, Yangyang; Lu, Zuhong

    2011-01-01

    In a sample of 466 Chinese high school students, we examined the relationships between Chinese high school students' stress in the school and their academic achievements. Regression mixture modelling identified two different classes of the effects of Chinese high school students' stress on their academic achievements. One class contained 87% of…

  14. The Effects of Magnet Schools on Neighborhood High Schools: An Examination of Achievement among Entering Freshmen

    ERIC Educational Resources Information Center

    Neild, Ruth Curran

    2004-01-01

    Magnet schools have been criticized for intensifying the concentration of disadvantaged, low-achieving students at neighborhood high schools. This article investigates the impact of academically selective magnet high schools on the average achievement of ninth graders enrolling in neighborhood high schools in a large urban school district. The…

  15. Beyond Academic Reputation: Factors that Influence the College of First Choice for High Achieving Students

    ERIC Educational Resources Information Center

    Schoenherr, Holly J.

    2009-01-01

    Studies that have investigated college choice factors for high-achieving students repeatedly cite academic reputation as one of the top indicators of choice but have not indicated why some high-achieving students choose to attend universities with a less prestigious reputation than the more highly prestigious options available to them. The purpose…

  16. Preferred Homework Style and Homework Environment in High- versus Low-Achieving Chinese Students.

    ERIC Educational Resources Information Center

    Hong, Eunsook; Lee, Kit-hung

    This study compared preferred homework styles of Chinese students who were characterized by: (1) high versus low self-perceived homework achievement and attitude; (2) high versus low teacher-rated homework completion and quality; (3) high versus low academic achievement in mathematics. Gender differences in homework styles were also examined.…

  17. THE STRUCTURE AND SPECTRAL FEATURES OF A THIN DISK AND EVAPORATION-FED CORONA IN HIGH-LUMINOSITY ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Liu, J. Y.; Mineshige, S. E-mail: bfliu@nao.cas.cn

    2012-08-01

    We investigate the accretion process in high-luminosity active galactic nuclei (HLAGNs) in the scenario of the disk evaporation model. Based on this model, the thin disk can extend down to the innermost stable circular orbit (ISCO) at accretion rates higher than 0.02 M-dot{sub Edd} while the corona is weak since part of the coronal gas is cooled by strong inverse Compton scattering of the disk photons. This implies that the corona cannot produce as strong X-ray radiation as observed in HLAGNs with large Eddington ratio. In addition to the viscous heating, other heating to the corona is necessary to interpret HLAGN. In this paper, we assume that a part of accretion energy released in the disk is transported into the corona, heating up the electrons, and is thereby radiated away. For the first time, we compute the corona structure with additional heating, fully taking into account the mass supply to the corona, and find that the corona could indeed survive at higher accretion rates and that its radiation power increases. The spectra composed of bremsstrahlung and Compton radiation are also calculated. Our calculations show that the Compton-dominated spectrum becomes harder with the increase of energy fraction (f) liberating in the corona, and the photon index for hard X-ray (2-10 keV) is 2.2 < {Gamma} < 2.7. We discuss possible heating mechanisms for the corona. Combining the energy fraction transported to the corona with the accretion rate by magnetic heating, we find that the hard X-ray spectrum becomes steeper at a larger accretion rate and the bolometric correction factor (L{sub bol}/L{sub 2-10keV}) increases with increasing accretion rate for f < 8/35, which is roughly consistent with the observational results.

  18. A COMPREHENSIVE STUDY OF THE MOTIVATIONAL FACTORS UNDERLYING ACHIEVEMENT OF ELEVENTH-GRADE HIGH SCHOOL STUDENTS.

    ERIC Educational Resources Information Center

    FARQUHAR, WILLIAM W.

    ACHIEVEMENT MOTIVATION WAS STUDIED BETWEEN OVER- AND UNDER-ACHIEVING STUDENTS IN THE ELEVENTH-GRADE TO DEVELOP AN OBJECTIVE MEASURE OF MOTIVATION FOR USE IN PREDICTING ACADEMIC SUCCESS OR FAILURE. APPROXIMATELY 800 STUDENTS IN PUBLIC HIGH SCHOOLS WERE SELECTED FOR VALIDATION AND CROSS-VALIDATION SAMPLES. THEY WERE DIVIDED BY SEX AND ACHIEVEMENT.…

  19. Does High School Facility Quality Affect Student Achievement? A Two-Level Hierarchical Linear Model

    ERIC Educational Resources Information Center

    Bowers, Alex J.; Urick, Angela

    2011-01-01

    The purpose of this study is to isolate the independent effects of high school facility quality on student achievement using a large, nationally representative U.S. database of student achievement and school facility quality. Prior research on linking school facility quality to student achievement has been mixed. Studies that relate overall…

  20. The Effects of Web-Based/Non-Web-Based Problem-Solving Instruction and High/Low Achievement on Students' Problem-Solving Ability and Biology Achievement

    ERIC Educational Resources Information Center

    Yu, Wen-Feng; She, Hsiao-Ching; Lee, Yu-Mei

    2010-01-01

    This study investigates the effects of two factors: the mode of problem-solving instruction (i.e. Web-based versus non-Web-based) and the level of academic achievement (i.e. high achievers versus low achievers) on students' problem-solving ability and biology achievement. A quasi-experimental design was used, in which the experimental group…

  1. An Analysis of Java Programming Behaviors, Affect, Perceptions, and Syntax Errors among Low-Achieving, Average, and High-Achieving Novice Programmers

    ERIC Educational Resources Information Center

    Rodrigo, Ma. Mercedes T.; Andallaza, Thor Collin S.; Castro, Francisco Enrique Vicente G.; Armenta, Marc Lester V.; Dy, Thomas T.; Jadud, Matthew C.

    2013-01-01

    In this article we quantitatively and qualitatively analyze a sample of novice programmer compilation log data, exploring whether (or how) low-achieving, average, and high-achieving students vary in their grasp of these introductory concepts. High-achieving students self-reported having the easiest time learning the introductory programming…

  2. International Note: Between-Domain Relations of Chinese High School Students' Academic Achievements

    ERIC Educational Resources Information Center

    Yangyang, Liu

    2012-01-01

    The present study examined the between-domain relations of Chinese high school students' academic achievements. In a sample of 1870 Chinese 10th grade students, the results indicated that Chinese high school students' academic achievements were correlated across nine subjects. In line with the previous Western findings, the findings suggested that…

  3. The Effect of the Time Management Art on Academic Achievement among High School Students in Jordan

    ERIC Educational Resources Information Center

    Al-Zoubi, Maysoon

    2016-01-01

    This study aimed at recognizing the effect of the Time Management Art on academic achievement among high school students in the Hashemite Kingdom of Jordan. The researcher employed the descriptive-analytic research to achieve the purpose of the study where he chose a sample of (2000) high school female and male students as respondents to the…

  4. High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; McCoach, D. Betsy

    2015-01-01

    Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

  5. A Longitudinal Investigation of Project-Based Instruction and Student Achievement in High School Social Studies

    ERIC Educational Resources Information Center

    Summers, Emily J.; Dickinson, Gail

    2012-01-01

    This longitudinal study focused on how project-based instruction (PBI) influenced secondary social studies students' academic achievement and promoted College and Career Readiness (CCR). We explored and compared student achievement in a PBI high school versus a traditional instruction high school within the same rural school district. While…

  6. The Meaning High-Achieving African-American Males in an Urban High School Ascribe to Mathematics

    ERIC Educational Resources Information Center

    Thompson, LaTasha; Davis, Julius

    2013-01-01

    Many researchers, educators, administrators, policymakers and members of the general public doubt the prevalence of high-achieving African-American males in urban high schools capable of excelling in mathematics. As part of a larger study, the current study explored the educational experiences of four high-achieving African-American males…

  7. Achieving high strength and high ductility in magnesium alloy using hard-plate rolling (HPR) process.

    PubMed

    Wang, Hui-Yuan; Yu, Zhao-Peng; Zhang, Lei; Liu, Chun-Guo; Zha, Min; Wang, Cheng; Jiang, Qi-Chuan

    2015-01-01

    Magnesium alloys are highly desirable for a wide range of lightweight structural components. However, rolling Mg alloys can be difficult due to their poor plasticity, and the strong texture yielded from rolling often results in poor plate forming ability, which limits their further engineering applications. Here we report a new hard-plate rolling (HPR) route which achieves a large reduction during a single rolling pass. The Mg-9Al-1Zn (AZ91) plates processed by HPR consist of coarse grains of 30-60 μm, exhibiting a typical basal texture, fine grains of 1-5 μm and ultrafine (sub) grains of 200-500 nm, both of the latter two having a weakened texture. More importantly, the HPR was efficient in gaining a simultaneous high strength and uniform ductility, i.e., ~371 MPa and ~23%, respectively. The superior properties should be mainly attributed to the cooperation effect of the multimodal grain structure and weakened texture, where the former facilitates a strong work hardening while the latter promotes the basal slip. The HPR methodology is facile and effective, and can avoid plate cracking that is prone to occur during conventional rolling processes. This strategy is applicable to hard-to-deform materials like Mg alloys, and thus has a promising prospect for industrial application. PMID:26603776

  8. Lipid target achievement among patients with very high and high cardiovascular risk in a lipid clinic.

    PubMed

    Barkas, Fotios; Liberopoulos, Evangelos N; Kostapanos, Michael S; Liamis, George; Tziallas, Dimitrios; Elisaf, Moses

    2015-04-01

    This was a retrospective study that assessed achievement of lipid-lowering treatment targets in the setting of a University Hospital Lipid Clinic. Low-density lipoprotein cholesterol (LDL-C) goal attainment according to National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III) and European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) guidelines was recorded in 1000 consecutive adult patients followed for ≥3 years (mean 8 years). The LDL-C targets according to the NCEP ATP III were attained by 66% and 86% of patients with "very high" (n = 477) and "high" (n = 408) cardiovascular risk, respectively. Fewer patients were within LDL-C goals according to the ESC/EAS guidelines: 25% and 42%. Overall, 92% of the patients were on statins: 67% were on statin monotherapy, while 33% were on combinations with ezetimibe (25%), ω-3 fatty acids (5%), fibrates (4%), or colesevelam (2%). Even in a specialist lipid clinic, a large proportion of patients are not at goal according to the recent ESC/EAS guidelines. PMID:24830420

  9. Achieving high strength and high ductility in magnesium alloy using hard-plate rolling (HPR) process.

    PubMed

    Wang, Hui-Yuan; Yu, Zhao-Peng; Zhang, Lei; Liu, Chun-Guo; Zha, Min; Wang, Cheng; Jiang, Qi-Chuan

    2015-11-25

    Magnesium alloys are highly desirable for a wide range of lightweight structural components. However, rolling Mg alloys can be difficult due to their poor plasticity, and the strong texture yielded from rolling often results in poor plate forming ability, which limits their further engineering applications. Here we report a new hard-plate rolling (HPR) route which achieves a large reduction during a single rolling pass. The Mg-9Al-1Zn (AZ91) plates processed by HPR consist of coarse grains of 30-60 μm, exhibiting a typical basal texture, fine grains of 1-5 μm and ultrafine (sub) grains of 200-500 nm, both of the latter two having a weakened texture. More importantly, the HPR was efficient in gaining a simultaneous high strength and uniform ductility, i.e., ~371 MPa and ~23%, respectively. The superior properties should be mainly attributed to the cooperation effect of the multimodal grain structure and weakened texture, where the former facilitates a strong work hardening while the latter promotes the basal slip. The HPR methodology is facile and effective, and can avoid plate cracking that is prone to occur during conventional rolling processes. This strategy is applicable to hard-to-deform materials like Mg alloys, and thus has a promising prospect for industrial application.

  10. Achieving high strength and high ductility in magnesium alloy using hard-plate rolling (HPR) process

    PubMed Central

    Wang, Hui–Yuan; Yu, Zhao–Peng; Zhang, Lei; Liu, Chun–Guo; Zha, Min; Wang, Cheng; Jiang, Qi–Chuan

    2015-01-01

    Magnesium alloys are highly desirable for a wide range of lightweight structural components. However, rolling Mg alloys can be difficult due to their poor plasticity, and the strong texture yielded from rolling often results in poor plate forming ability, which limits their further engineering applications. Here we report a new hard-plate rolling (HPR) route which achieves a large reduction during a single rolling pass. The Mg-9Al-1Zn (AZ91) plates processed by HPR consist of coarse grains of 30–60 μm, exhibiting a typical basal texture, fine grains of 1–5 μm and ultrafine (sub) grains of 200–500 nm, both of the latter two having a weakened texture. More importantly, the HPR was efficient in gaining a simultaneous high strength and uniform ductility, i.e., ~371 MPa and ~23%, respectively. The superior properties should be mainly attributed to the cooperation effect of the multimodal grain structure and weakened texture, where the former facilitates a strong work hardening while the latter promotes the basal slip. The HPR methodology is facile and effective, and can avoid plate cracking that is prone to occur during conventional rolling processes. This strategy is applicable to hard-to-deform materials like Mg alloys, and thus has a promising prospect for industrial application. PMID:26603776

  11. Luminosity class of neutron reflectometers

    NASA Astrophysics Data System (ADS)

    Pleshanov, N. K.

    2016-10-01

    The formulas that relate neutron fluxes at reflectometers with differing q-resolutions are derived. The reference luminosity is defined as a maximum flux for measurements with a standard resolution. The methods of assessing the reference luminosity of neutron reflectometers are presented for monochromatic and white beams, which are collimated with either double diaphragm or small angle Soller systems. The values of the reference luminosity for unified parameters define luminosity class of reflectometers. The luminosity class characterizes (each operation mode of) the instrument by one number and can be used to classify operating reflectometers and optimize designed reflectometers. As an example the luminosity class of the neutron reflectometer NR-4M (reactor WWR-M, Gatchina) is found for four operation modes: 2.1 (monochromatic non-polarized beam), 1.9 (monochromatic polarized beam), 1.5 (white non-polarized beam), 1.1 (white polarized beam); it is shown that optimization of measurements may increase the flux at the sample up to two orders of magnitude with monochromatic beams and up to one order of magnitude with white beams. A fan beam reflectometry scheme with monochromatic neutrons is suggested, and the expected increase in luminosity is evaluated. A tuned-phase chopper with a variable TOF resolution is recommended for reflectometry with white beams.

  12. Decreased latent inhibition is associated with increased creative achievement in high-functioning individuals.

    PubMed

    Carson, Shelley H; Peterson, Jordan B; Higgins, Daniel M

    2003-09-01

    Reductions in latent inhibition (LI), the capacity to screen from conscious awareness stimuli previously experienced as irrelevant, have been generally associated with the tendency towards psychosis. However, "failure" to screen out previously irrelevant stimuli might also hypothetically contribute to original thinking, particularly in combination with high IQ. Meta-analysis of two studies, conducted on youthful high-IQ samples. demonstrated that high lifetime creative achievers had significantly lower LI scores than low creative achievers (r(effect size) = .31, p = .0003, one-tailed). Eminent creative achievers (participants under 21 years who reported unusually high scores in a single domain of creative achievement) were 7 times more likely to have low rather than high LI scores, chi2 (1, N = 25) = 10.69, phi = .47. p = .003.

  13. Understanding and Reversing Underachievement, Low Achievement, and Achievement Gaps among High-Ability African American Males in Urban School Contexts

    ERIC Educational Resources Information Center

    Ford, Donna Y.; Moore, James L., III

    2013-01-01

    This article focuses on the achievement gap, with attention devoted to underachievement and low achievement among African American males in urban school contexts. More specifically, the article explains problems and issues facing or confronting these Black male students in urban education settings. A central part of this discussion is grounded in…

  14. Support Structure Design of the $\\hbox{Nb}_{3}\\hbox{Sn}$ Quadrupole for the High Luminosity LHC

    SciTech Connect

    Juchno, M.; Ambrosio, G.; Anerella, M.; Cheng, D.; Felice, H.; Ferracin, P.; Perez, J. C.; Prin, H.; Schmalzle, J.

    2014-10-31

    New low-β quadrupole magnets are being developed within the scope of the High Luminosity LHC (HL-LHC) project in collaboration with the US LARP program. The aim of the HLLHC project is to study and implement machine upgrades necessary for increasing the luminosity of the LHC. The new quadrupoles, which are based on the Nb₃Sn superconducting technology, will be installed in the LHC Interaction Regions and will have to generate a gradient of 140 T/m in a coil aperture of 150 mm. In this paper, we describe the design of the short model magnet support structure and discuss results of the detailed 3D numerical analysis performed in preparation for the first short model test.

  15. Instructional, Transformational, and Managerial Leadership and Student Achievement: High School Principals Make a Difference

    ERIC Educational Resources Information Center

    Valentine, Jerry W.; Prater, Mike

    2011-01-01

    This statewide study examined the relationships between principal managerial, instructional, and transformational leadership and student achievement in public high schools. Differences in student achievement were found when schools were grouped according to principal leadership factors. Principal leadership behaviors promoting instructional and…

  16. Low and High Mathematics Achievement in Japanese, Chinese, and American Elementary-School Children.

    ERIC Educational Resources Information Center

    Uttal, David H.; And Others

    1988-01-01

    First and fifth grade students who scored high or low on a mathematics test were tested for intellectual ability and reading achievement. Students and their mothers were interviewed. Results indicated that factors associated with levels of achievement in mathematics operate in a similar fashion across three cultures that differ greatly in their…

  17. Accelerated Mathematics and High-Ability Students' Math Achievement in Grades Three and Four

    ERIC Educational Resources Information Center

    Stanley, Ashley M.

    2011-01-01

    The purpose of this study was to explore the relationship between the use of a computer-managed integrated learning system entitled Accelerated Math (AM) as a supplement to traditional mathematics instruction on achievement as measured by TerraNova achievement tests of third and fourth grade high-ability students. Gender, socioeconomic status, and…

  18. A Quantitative Comparison of Pennsylvania High School Student Achievement by Middle States Association's Accreditation Status

    ERIC Educational Resources Information Center

    Johnson, Christopher A.

    2012-01-01

    As public school accountability for student achievement has continued to increase, prior to and as a result of the No Child Left Behind Act of 2001, schools have sought ways of bringing new instructional services to their students to raise their levels of achievement. Some Pennsylvania public high schools have attempted to improve student…

  19. Achievement Motivation in High School: Contrasting Theoretical Models in the Classroom.

    ERIC Educational Resources Information Center

    Garcia-Celay, I. Montero; Tapia, J. Alonso

    1992-01-01

    Three models of achievement motivation in the classroom are contrasted. Results with 155 high school students suggest that the model of C. S. Dweck and E. S. Elliott offers a better explanation of the relationships among achievement motivation, attributions, emotional reactions, expectancies, and performance than do the other models. (SLD)

  20. The Effects of Cooperative Learning on Student Achievement and Motivation in a High School Geometry Class.

    ERIC Educational Resources Information Center

    Nichols, Joe D.; Hall, Neff

    In this study, the effects of a form of cooperative group instruction (Student Teams Achievement Divisions) on student motivation and achievement in a high school geometry class were examined. Ninety (mostly 10th-grade) students were randomly assigned to either a control group receiving traditional instruction or one of two treatment groups…

  1. Early Reading Skills and Academic Achievement Trajectories of Students Facing Poverty, Homelessness, and High Residential Mobility

    ERIC Educational Resources Information Center

    Herbers, Janette E.; Cutuli, J. J.; Supkoff, Laura M.; Heistad, David; Chan, Chi-Keung; Hinz, Elizabeth; Masten, Ann S.

    2012-01-01

    This investigation tested the importance of early academic achievement for later achievement trajectories among 18,011 students grouped by level of socioeconomic risk. Students considered to be at highest risk were those who experienced homelessness or high residential mobility (HHM). HHM students were compared with students eligible for free…

  2. Intergenerational Closure and Academic Achievement in High School: A New Evaluation of Coleman's Conjecture

    ERIC Educational Resources Information Center

    Morgan, Stephen L.; Todd, Jennifer J.

    2009-01-01

    This article reexamines the conjecture of James S. Coleman that intergenerational social closure promotes student achievement in high schools, analyzing the best national data on academic achievement and social networks: the 2002 and 2004 waves of the Education Longitudinal Study. The results show that within the Catholic school sector, schools…

  3. Unforgiving Confucian Culture: A Breeding Ground for High Academic Achievement, Test Anxiety and Self-Doubt?

    ERIC Educational Resources Information Center

    Stankov, Lazar

    2010-01-01

    This paper reviews findings from several studies that contribute to our understanding of cross-cultural differences in academic achievement, anxiety and self-doubt. The focus is on comparisons between Confucian Asian and European regions. Recent studies indicate that high academic achievement of students from Confucian Asian countries is…

  4. Gender and High School Chemistry: Student Perceptions on Achievement in a Selective Setting

    ERIC Educational Resources Information Center

    Cousins, Andrew; Mills, Martin

    2015-01-01

    This paper reports on research undertaken in a middle-class Australian school. The focus of the research was on the relationship between gender and students' engagement with high school chemistry. Achievement data from many OECD [Organisation for Economic Co-operation and Development] countries suggest that middle-class girls are achieving equally…

  5. Parental Involvement, Homework, and TV Time: Direct and Indirect Effects on High School Achievement.

    ERIC Educational Resources Information Center

    Keith, Timothy Z.; And Others

    1986-01-01

    A set of High School and Beyond data was used to study the effect of three variables on academic achievement. Homework had a positive effect, TV a negative, and parental involvement no direct effect on seniors' achievement scores, but influenced the amount of time students spent on homework. (Author/JAZ)

  6. A Survey of Luminous High-redshift Quasars with SDSS and WISE. II. the Bright End of the Quasar Luminosity Function at z ≈ 5

    NASA Astrophysics Data System (ADS)

    Yang, Jinyi; Wang, Feige; Wu, Xue-Bing; Fan, Xiaohui; McGreer, Ian D.; Bian, Fuyan; Yi, Weimin; Yang, Qian; Ai, Yanli; Dong, Xiaoyi; Zuo, Wenwen; Green, Richard; Jiang, Linhua; Wang, Shu; Wang, Ran; Yue, Minghao

    2016-09-01

    This is the second paper in a series on a new luminous z ˜ 5 quasar survey using optical and near-infrared colors. Here we present a new determination of the bright end of the quasar luminosity function (QLF) at z ˜ 5. Combining our 45 new quasars with previously known quasars that satisfy our selections, we construct the largest uniform luminous z ˜ 5 quasar sample to date, with 99 quasars in the range of 4.7 ≤ z < 5.4 and -29 < M 1450 ≤ -26.8, within the Sloan Digital Sky Survey (SDSS) footprint. We use a modified 1/V a method including flux limit correction to derive a binned QLF, and we model the parametric QLF using maximum likelihood estimation. With the faint-end slope of the QLF fixed as α = -2.03 from previous deeper samples, the best fit of our QLF gives a flatter bright end slope β = -3.58 ± 0.24 and a fainter break magnitude {M}1450* = -26.98 ± 0.23 than previous studies at similar redshift. Combined with previous work at lower and higher redshifts, our result is consistent with a luminosity evolution and density evolution model. Using the best-fit QLF, the contribution of quasars to the ionizing background at z ˜ 5 is found to be 18%-45% with a clumping factor C of 2-5. Our sample suggests an evolution of radio loud fraction with optical luminosity but no obvious evolution with redshift.

  7. Ion bunch length effects on the beam-beam interaction and its compensation in a high-luminosity ring-ring electron-ion collider

    SciTech Connect

    Montag C.; Oeftiger, A.; Fischer, W.

    2012-05-20

    One of the luminosity limits in a ring-ring electron-ion collider is the beam-beam effect on the electrons. In the limit of short ion bunches, simulation studies have shown that this limit can be significantly increased by head-on beam-beam compensation with an electron lens. However, with an ion bunch length comparable to the beta-function at the IP in conjunction with a large beam-beam parameter, the electrons perform a sizeable fraction of a betatron oscillation period inside the long ion bunches. We present recent simulation results on the compensation of this beam-beam interaction with multiple electron lenses.

  8. Impacts of comprehensive reading instruction on diverse outcomes of low- and high-achieving readers.

    PubMed

    Guthrie, John T; McRae, Angela; Coddington, Cassandra S; Lutz Klauda, Susan; Wigfield, Allan; Barbosa, Pedro

    2009-01-01

    Low-achieving readers in Grade 5 often lack comprehension strategies, domain knowledge, word recognition skills, fluency, and motivation to read. Students with such multiple reading needs seem likely to benefit from instruction that supports each of these reading processes. The authors tested this expectation experimentally by comparing the effects of Concept-Oriented Reading Instruction (CORI) with traditional instruction (TI) on several outcomes in a 12-week intervention for low achievers and high achievers. Low achievers in the CORI group were afforded explicit instruction, leveled texts, and motivation support. Compared with TI students, CORI students scored higher on posttest measures of word recognition speed, reading comprehension on the Gates-MacGinitie Reading Test, and ecological knowledge. CORI was equally effective for lower achievers and higher achievers. Explicitly supporting multiple aspects of reading simultaneously appeared to benefit diverse learners on a range of reading outcomes.

  9. Understanding the Elements of Operational Reliability: A Key for Achieving High Reliability

    NASA Technical Reports Server (NTRS)

    Safie, Fayssal M.

    2010-01-01

    This viewgraph presentation reviews operational reliability and its role in achieving high reliability through design and process reliability. The topics include: 1) Reliability Engineering Major Areas and interfaces; 2) Design Reliability; 3) Process Reliability; and 4) Reliability Applications.

  10. Luminosity function for galaxy clusters

    NASA Astrophysics Data System (ADS)

    Bajan, K.; Biernacka, M.; Flin, P.; Godłowski, W.; Panko, E.; Popiela, J.

    2016-10-01

    We constructed and studied the luminosity function of 6188 galaxyclusters. This was performed by counting brightness of galaxiesbelonging to clusters in the PF catalogue, taking galaxy data fromMRSS. Our result shows that the investigated structures arecharacterized by a luminosity function different from that ofoptical galaxies and radiogalaxies (Machalski & Godłowski2000). The implications of this result for theoriesof galaxy formation are briefly discussed.

  11. Do Peers Influence Achievement in High School Economics? Evidence from Georgia's Economics End of Course Test

    ERIC Educational Resources Information Center

    Clark, Christopher; Scafidi, Benjamin; Swinton, John R.

    2011-01-01

    The authors provide the first estimates of the impact of peers on achievement in high school economics. The estimates are obtained by analyzing three years of data on all high school students who take Georgia's required economics course and its accompanying high-stakes End of Course Test (Georgia Department of Education). They use an instrumental…

  12. A Study of Professional Learning Communities and Science Achievement in Large High Schools

    ERIC Educational Resources Information Center

    Kincannon, Susan D.

    2010-01-01

    The purpose of this study was to compare the science achievement and high school completion rates of students in a large high school implementing professional learning community concepts and practices with two large high schools not participating in professional learning community concepts and practices. The primary methodology employed was a…

  13. The Outward Bound Bridging Course for Low-Achieving High School Males: Effect on Academic Achievement and Multidimensional Self-Concepts.

    ERIC Educational Resources Information Center

    Marsh, Herbert W.; Richards, Garry

    The Outward Bound Bridging Course is a 6-week residential program designed to improve academic achievement and self-concepts in low-achieving high school males. During 1980-1984, five courses were conducted for 66 Australian high school males. Most of them were ninth grade students, chosen on the basis of poor academic performance, an apparent…

  14. A Comparison of Emotional-Motivational (A-R-D Theory) Personality Characteristics in Learning Disabled, Normal Achieving, and High Achieving Children.

    ERIC Educational Resources Information Center

    Hufano, Linda D.

    The study examined emotional-motivational personality characteristics of 15 learning disabled, 15 normal achieving, and 15 high achieving students (grades 3-5). The study tested the hypothesis derived from the A-R-D (attitude-reinforcer-discriminative) theory of motivation that learning disabled (LD) children differ from normal and high achieving…

  15. Social Goals, Social Status, and Problem Behavior among Low-Achieving and High-Achieving Adolescents from Rural Schools

    ERIC Educational Resources Information Center

    Ludden, Alison Bryant

    2012-01-01

    The current research examines how social goals and perceptions of what is needed for social status at school relate to school misbehavior and substance use among rural adolescents (N = 683). Results indicate that social goals and perceptions of social status have differential links to problem behaviors depending upon adolescents' achievement.…

  16. Evaluation of English Achievement Test: A Comparison between High and Low Achievers amongst Selected Elementary School Students of Pakistan

    ERIC Educational Resources Information Center

    Haider, Zubair; Latif, Farah; Akhtar, Samina; Mushtaq, Maria

    2012-01-01

    Validity, reliability and item analysis are critical to the process of evaluating the quality of an educational measurement. The present study evaluates the quality of an assessment constructed to measure elementary school student's achievement in English. In this study, the survey model of descriptive research was used as a research method.…

  17. A complete X-ray sample of the high latitude sky from HEAO-1 A-2: log N lo S and luminosity functions

    NASA Technical Reports Server (NTRS)

    Piccinotti, G.; Mushotzky, R. F.; Boldt, E. A.; Holt, S. S.; Marshall, F. E.; Serlemitsos, P. J.; Shafer, R. A.

    1981-01-01

    An experiment was performed in which a complete X-ray survey of the 8.2 steradians of the sky at galactic latitudes where the absolute value of b is 20 deg down to a limiting sensitivity of 3.1 x ten to the minus 11th power ergs/sq cm sec in the 2-10 keV band. Of the 85 detected sources 17 were identified with galactic objects, 61 were identified with extragalactic objects, and 7 remain unidentified. The log N - log S relation for the non-galactic objects is well fit by the Euclidean relationship. The X-ray spectra of these objects were used to construct log N - log S in physical units. The complete sample of identified sources was used to construct X-ray luminosity functions, using the absolute maximum likelihood method, for clusters galaxies and active galactic nuclei.

  18. Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. V. A New Size-Luminosity Scaling Relation for the Broad-line Region

    NASA Astrophysics Data System (ADS)

    Du, Pu; Lu, Kai-Xing; Zhang, Zhi-Xiang; Huang, Ying-Ke; Wang, Kai; Hu, Chen; Qiu, Jie; Li, Yan-Rong; Fan, Xu-Liang; Fang, Xiang-Er; Bai, Jin-Ming; Bian, Wei-Hao; Yuan, Ye-Fei; Ho, Luis C.; Wang, Jian-Min; SEAMBH Collaboration

    2016-07-01

    This paper reports results of the third-year campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs) between 2014 and 2015. Ten new targets were selected from the quasar sample of the Sloan Digital Sky Survey (SDSS), which have generally been more luminous than the SEAMBH candidates in the last two years. Hβ lags ({τ }{{H}β }) in five of the 10 quasars have been successfully measured in this monitoring season. We find that the lags are generally shorter, by large factors, than those of objects with same optical luminosity, in light of the well-known R H β-L 5100 relation. The five quasars have dimensionless accretion rates of \\dot{{M}\\quad }=10-103. Combining these with measurements of the previous SEAMBHs, we find that the reduction of Hβ lags depends tightly on accretion rates, {τ }{{H}β }/{τ }R-L\\propto {\\dot{{M}}}-0.42, where {τ }R-L is the Hβ lag from the normal R H β-L 5100 relation. Fitting 63 mapped AGNs, we present a new scaling relation for the broad-line region: {R}{{H}β }={α }1{{\\ell }}44{β 1} {min} [1,{(\\dot{{M}}/{\\dot{{M}}}c)}-{γ 1}], where {{\\ell }}44={L}5100/{10}44 {erg} {{{s}}}-1 is the 5100 Å continuum luminosity, and the coefficients are {α }1={29.6}-2.8+2.7 lt-day, {β }1={0.56}-0.03+0.03, {γ }1={0.52}-0.16+0.33, and {\\dot{{M}}}c={11.19}-6.22+2.29. This relation is applicable to AGNs over a wide range of accretion rates, from 10-3 to 103. Implications of this new relation are briefly discussed.

  19. Emotional Intelligence as a Predictor of Leadership of Kuwaiti High and Low Achieving 11th Graders

    ERIC Educational Resources Information Center

    Alnabhan, Mousa

    2010-01-01

    The current study examined the association between emotional intelligence (EI) and the Leadership components (L) of high school students in the state of Kuwait. The possibility of predicting each leadership component via emotional intelligence components was investigated for high and low achievers. A sample of 11th grade students from Kuwaiti…

  20. What Works Clearinghouse Quick Review: "Expanding College Opportunities for High-Achieving, Low Income Students"

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2013

    2013-01-01

    This study examined the effects of providing low-income, high-achieving high school seniors with college application guidance and information about the costs of college. The "application guidance" included information about deadlines and requirements for college applications at nearby institutions, at the state's flagship institution, and at in-…

  1. The Effects of Modeling Instruction on High School Physics Academic Achievement

    ERIC Educational Resources Information Center

    Wright, Tiffanie L.

    2012-01-01

    The purpose of this study was to explore whether Modeling Instruction, compared to traditional lecturing, is an effective instructional method to promote academic achievement in selected high school physics classes at a rural middle Tennessee high school. This study used an "ex post facto," quasi-experimental research methodology. The…

  2. Effects of an Elementary Dual Language Immersion School Program on Junior High Achievement

    ERIC Educational Resources Information Center

    Cobb, Brian; Vega, Diego; Kronauge, Cindy

    2006-01-01

    The purpose of this study was to analyze the effects of a two-way immersion elementary school program on academic achievement at the end of the elementary school and the end of the first year of junior high school. Longitudinal high stakes test data in reading, writing, and mathematics were collected on native English speakers and native Spanish…

  3. The Relationship between Self-Efficacy and Achievement in At-Risk High School Students

    ERIC Educational Resources Information Center

    Gold, Jarrett Graham

    2010-01-01

    The focus of this quantitative survey study was the examination of the relationship between self-efficacy and academic achievement in 164 at-risk high school students. The study used Bandura's self-efficacy as the theoretical framework. The research questions involved understanding the levels of self-efficacy in at-risk high school students and…

  4. Small Classes in the Early Grades, Academic Achievement, and Graduating From High School

    ERIC Educational Resources Information Center

    Finn, Jeremy D.; Gerber, Susan B.; Boyd-Zaharias, Jayne

    2005-01-01

    This investigation addressed 3 questions about the long-term effects of early school experiences: (a) Is participation in small classes in the early grades (K-3) related to high school graduation? (b) Is academic achievement in K-3 related to high school graduation? (c) If class size is related to graduation, is the relationship explained by the…

  5. Mathematics Achievement with Digital Game-Based Learning in High School Algebra 1 Classes

    ERIC Educational Resources Information Center

    Ferguson, Terri Lynn Kurley

    2014-01-01

    This study examined the impact of digital game-based learning (DGBL) on mathematics achievement in a rural high school setting in North Carolina. A causal comparative research design was used in this study to collect data to determine the effectiveness of DGBL in high school Algebra 1 classes. Data were collected from the North Carolina…

  6. Towards Promoting Biliteracy and Academic Achievement: Educational Programs for High School Latino English Language Learners

    ERIC Educational Resources Information Center

    Ochoa, Alberto M.; Cadiero-Kaplan, Karen

    2004-01-01

    The Latino student presently faces many obstacles to achieve educational equity and excellence at the high school level. This article examines academic programming for Latino middle and high school English language learners (ELLs) and provides recommendations for addressing programming that promotes biliteracy policy and programming as a valued…

  7. A Case Study of 21st Century Skills in High Achieving Elementary Schools in Pennsylvania

    ERIC Educational Resources Information Center

    Egnor, Gregory P.

    2013-01-01

    This study examines if practices that advocate for 21st century skills are in conflict with the mandates of NCLB. Interviews with influential school leaders of high achieving elementary schools focused on collecting data about 21st century skills. This study was designed to (a) Determine if 21st century skills are addressed in high achieving…

  8. Achieve Scholarship Spending on Expanding Access to Rigorous High School Courses

    ERIC Educational Resources Information Center

    Minnesota Office of Higher Education, 2009

    2009-01-01

    The 2007 Legislature enacted the Achieve Scholarship program, which provides a $1,200 scholarship to high school graduates who took rigorous courses in high school and met certain income and other eligibility criteria. In deliberations about this new program, concerns were expressed that certain rigorous courses like Advanced Placement,…

  9. Study-Orientation of High and Low Academic Achievers at Secondary Level in Pakistan

    ERIC Educational Resources Information Center

    Sarwar, Muhammad; Bashir, Muhammad; Khan, Muhammad Naemullah; Khan, Muhammad Saeed

    2009-01-01

    The study orientation of low and high academic achievers was compared, measured through a self-developed study orientation scale (SOS) primarily based on 47 items comparing study habits and attitude. Students' marks obtained in the 10th grade Examination determined the measure of academic performance. The analysis revealed that the high achievers…

  10. Does Homogeneous Ability Grouping for High School Honors English Instruction Benefit the High Achiever?

    ERIC Educational Resources Information Center

    Hostetter, Douglas Paul

    2013-01-01

    Public schools are examining their policies and instructional practices to address the achievement gap exposed by the reporting requirements of NCLB (Wenglinski, 2004). As accountability measures and stakes rise, there is a call for an improved use of scientific evidence to inform educational policymaking (Wiseman, 2010). In terms of the…

  11. Patterns of Self-Regulation: Patterns of Self-Regulatory Strategy Use among Low-Achieving and High-Achieving University Students

    ERIC Educational Resources Information Center

    Ruban, Lilia; Reis, Sally M.

    2006-01-01

    The present mixed-methods study attempts to provide insights into the nature, idiosyncrasies, and inter- and intra-individual patterns of academic self-regulatory strategy use among two different populations of university students. Low-achieving (n = 49) and high-achieving students (n = 131) described their self-regulatory strategy use in their…

  12. Factors That Influence School Board Actions to Support Student Achievement: A Multi-Case Study of High-Achieving Rural School Districts

    ERIC Educational Resources Information Center

    Timm, Colleen A.

    2012-01-01

    The purpose of this study is to examine the factors that influence the actions taken by school boards that advance student achievement in high-achieving rural public school districts. Much of what is discussed in the literature on school improvement efforts is centered on the work carried out by school personnel at the school level. What is…

  13. High frequency wide-band transformer uses coax to achieve high turn ratio and flat response

    NASA Technical Reports Server (NTRS)

    De Parry, T.

    1966-01-01

    Center-tap push-pull transformer with toroidal core helically wound with a single coaxial cable creates a high frequency wideband transformer. This transformer has a high-turn ratio, a high coupling coefficient, and a flat broadband response.

  14. Effects of a Collaborative Science Intervention on High Achieving Students' Learning Anxiety and Attitudes toward Science

    NASA Astrophysics Data System (ADS)

    Hong, Zuway-R.

    2010-10-01

    This study investigated the effects of a collaborative science intervention on high achieving students' learning anxiety and attitudes toward science. Thirty-seven eighth-grade high achieving students (16 boys and 21 girls) were selected as an experimental group who joined a 20-week collaborative science intervention, which integrated and utilized an innovative teaching strategy. Fifty-eight eighth-grade high achieving students were selected as the comparison group. The Secondary School Student Questionnaire was conducted to measure all participants' learning anxiety and attitudes toward science. In addition, 12 target students from the experimental group (i.e., six active and six passive students) were recruited for weekly classroom observations and follow-up interviews during the intervention. Both quantitative and qualitative findings revealed that experimental group students experienced significant impact as seen through increased attitudes and decreased anxiety of learning science. Implications for practice and research are provided.

  15. School factors affecting postsecondary career pursuits of high-achieving girls in mathematics and science

    NASA Astrophysics Data System (ADS)

    Yoo, Hyunsil

    This study examined the influences of secondary school experiences of high-achieving girls in math and science on their postsecondary career pursuits in science fields. Specifically, using the National Education Longitudinal Study of 1988 (NELS:88), the study investigated how science class experiences in high school affect science career persistence of high-achieving girls over and above personal and family factors. Selecting the top 10% on the 8 th grade math and science achievement tests from two panel samples of 1988--1994 and 1988--2000, this study examined which science instructional experiences (i.e., lecture-oriented, experiment-oriented, and student-oriented) best predicted college major choices and postsecondary degree attainments in the fields of science after controlling for personal and family factors. A two-stage test was employed for the analysis of each panel sample. The first test examined the dichotomous career pursuits between science careers and non-science careers and the second test examined the dichotomous pursuits within science careers: "hard" science and "soft" science. Logistic regression procedures were used with consideration of panel weights and design effects. This study identified that experiment-oriented and student-oriented instructional practices seem to positively affect science career pursuits of high-achieving females, while lecture-oriented instruction negatively affected their science career pursuits, and that the longitudinal effects of the two positive instructional contributors to science career pursuits appear to be differential between major choice and degree attainment. This study also found that the influences of instructional practices seem to be slight for general females, while those for high-achieving females were highly considerable, regardless of whether negative or positive. Another result of the study found that only student-oriented instruction seemed to have positive effects for high-achieving males. In

  16. Diamond Pixel Luminosity Telescopes

    SciTech Connect

    Halyo, Valerie

    2014-12-23

    In this document, Halyo summaries her key contributions to CMS at the LHC and provide an explanation of their importance and her role in each project. At the end Halyo describes her recent research interest that includes GPU/MIC Acceleration of the High Level Trigger (HLT) to Extend the Physics Research at the LHC. A descriptionof her work the recent promising results that she accomplished and the deliverable are also elaborated. These contribution were only possible thanks to DOE support of junior faculty research and their clear goal to promote research and innovations. Princeton University i

  17. Evolutionary variations of solar luminosity

    NASA Technical Reports Server (NTRS)

    Endal, A. S.

    1981-01-01

    Theoretical arguments for a 30% increase in the solar luminosity over the past 4.7 billion years are reviewed. A scaling argument shows that this increase can be predicted without detailed numerical calculations. The magnitude of the increase is independent of nuclear reaction rates, as long as conversion of hydrogen to helium provides the basic energy source of the Sun. The effect of the solar luminosity increase on the terrestrial climate is briefly considered. It appears unlikely that an enhanced greenhouse effect, due to reduced gases (NH3, CH4), can account for the long-term paleoclimatic trends.

  18. Four luminosity indicators for gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Schaefer, B.

    Recently, two luminosity indicators involving gamma-ray data alone have been discovered. The first is the spectral lag, which is roughly the time between peaks in the light curve as viewed with ~30 and ~200 keV photons, such that high luminosity events have short lags and low luminosities are indicated by lags as long as 1 second or more. The second luminosity indicator is the variability, which is a quantitative measure of how 'spiky' the burst light curve is, with spiky bursts having high luminosity while smooth bursts have low luminosity. These two indicators were originally proposed with either 6 or 7 bursts with redshifts. The validity of both indicators is proven by the existence of a lag/variability relation exactly as predicted for a sample of 112 BATSE bursts as well as by 3 additional bursts which also fall onto the claimed relations. Now, two new luminosity indicators have been identified. The third is the minimum risetime for pulses in a burst light curve, where fast rises indicate high luminosities and slow rises are for low luminosity events. The fourth indicator is the number of distinct peaks in the burst light curve, although this only sets a limit where the luminosity must be greater than roughly 1050 erg/s times the square of the number of peaks (for more than one peak). This talk will also present simple and general explanations for all four luminosity indicators. The lag/luminosity relation is a simple and forced result from the empirical Liang-Kargatis relation which simply implies that radiative cooling is dominating. The fastest rise in a light curve is related to the bulk Lorentz factor (Gamma) simply due to the geometrical rise time for a region subtending an angle of 1/Gamma (given that the minimal radius for which the optical depth of the jet material is of order unity is empirically a near constant). The luminosity of the burst is also a power law of Gamma, which scales as Gamma^N for 3luminosity

  19. "It's a Way of Life for Us": High Mobility and High Achievement in Department of Defense Schools.

    ERIC Educational Resources Information Center

    Smrekar, Claire E.; Owens, Debra E.

    2003-01-01

    Examines the academic performance of students in U.S. Department of Defense Education Activity (DoDEA) schools, which have high student mobility. Some observers contend that these students' high achievement is a function of their middle class family and community characteristics. Asserts that DoDEA schools simultaneously "do the right things" and…

  20. The white dwarf luminosity function

    NASA Astrophysics Data System (ADS)

    García-Berro, Enrique; Oswalt, Terry D.

    2016-06-01

    White dwarfs are the final remnants of low- and intermediate-mass stars. Their evolution is essentially a cooling process that lasts for ∼ 10 Gyr. Their observed properties provide information about the history of the Galaxy, its dark matter content and a host of other interesting astrophysical problems. Examples of these include an independent determination of the past history of the local star formation rate, identification of the objects responsible for the reported microlensing events, constraints on the rate of change of the gravitational constant, and upper limits to the mass of weakly interacting massive particles. To carry on these tasks the essential observational tools are the luminosity and mass functions of white dwarfs, whereas the theoretical tools are the evolutionary sequences of white dwarf progenitors, and the corresponding white dwarf cooling sequences. In particular, the observed white dwarf luminosity function is the key manifestation of the white dwarf cooling theory, although other relevant ingredients are needed to compare theory and observations. In this review we summarize the recent attempts to empirically determine the white dwarf luminosity function for the different Galactic populations. We also discuss the biases that may affect its interpretation. Finally, we elaborate on the theoretical ingredients needed to model the white dwarf luminosity function, paying special attention to the remaining uncertainties, and we comment on some applications of the white dwarf cooling theory. Astrophysical problems for which white dwarf stars may provide useful leverage in the near future are also discussed.

  1. Spatial Experiences of High Academic Achievers: Insights from a Developmental Perspective

    ERIC Educational Resources Information Center

    Weckbacher, Lisa Marie; Okamoto, Yukari

    2012-01-01

    The study explored the relationship between types of spatial experiences and spatial abilities among 13- to 14-year-old high academic achievers. Each participant completed two spatial tasks and a survey assessing favored spatial activities across five categories (computers, toys, sports, music, and art) and three developmental periods (early…

  2. High-Stakes Testing and Student Achievement: Updated Analyses with NAEP Data

    ERIC Educational Resources Information Center

    Nichols, Sharon L.; Glass, Gene V.; Berliner, David C.

    2012-01-01

    The present research is a follow-up study of earlier published analyses that looked at the relationship between high-stakes testing pressure and student achievement in 25 states. Using the previously derived Accountability Pressure Index (APR) as a measure of state-level policy pressure for performance on standardized tests, a series of…

  3. Performance-Approach Goal Effects on Achievement under Low versus High Challenge Conditions

    ERIC Educational Resources Information Center

    Senko, Corwin; Durik, Amanda M.; Patel, Lily; Lovejoy, Chelsea M.; Valentiner, David

    2013-01-01

    Two studies examined the effects of university students' achievement goals on performance under low versus high challenge conditions. The first was a laboratory experiment in which participants were assigned goals to pursue on a novel mathematics task alleged to be simple or complex to use. The second was a survey study in which students set goals…

  4. Impact of Physical Environment on Academic Achievement of High School Youth.

    ERIC Educational Resources Information Center

    Burkhalter, Bettye B.

    1983-01-01

    To study the relationship of the physical environment to high school students' academic achievement, 60 students participated in an experiential career exploration program at the Alabama Space and Rocket Center while 108 students participated in a traditional careers program. Tests indicated the former group improved more in career choice…

  5. Universal Factors of Student Achievement in High-Performing Eastern and Western Countries

    ERIC Educational Resources Information Center

    Lee, Jihyun

    2014-01-01

    This study investigates whether a common set of student attitudes and behavioral tendencies can account for academic achievement across different, especially high-performing, countries via analysis of the PISA 2009 international data set. The 13 countries examined are 5 of the top-performing Eastern countries/systems, namely Shanghai China, South…

  6. The Federal Transformation Intervention Model in Persistently Lowest Achieving High Schools: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Le Patner, Michelle B.

    2012-01-01

    This study examined the American Recovery and Reinvestment Act federal mandate of the Transformation Intervention Model (TIM) outlined by the School Improvement Grant, which was designed to turn around persistently lowest achieving schools. The study was conducted in four high schools in a large Southern California urban district that selected the…

  7. Excellence in English in Middle and High School: How Teachers' Professional Lives Support Student Achievement.

    ERIC Educational Resources Information Center

    Langer, Judith A.

    The Center on English Learning and Achievement (CELA) has been studying the characteristics of successful English programs in middle and high schools. This report discusses the findings of the first two years of their 5-year Excellence in English study and focuses on the educational practices that support student literacy as well as the…

  8. Social Media Use, Loneliness, and Academic Achievement: A Correlational Study with Urban High School Students

    ERIC Educational Resources Information Center

    Neto, Roque; Golz, Nancy; Polega, Meaghan

    2015-01-01

    This study explored the association between social media use, loneliness, and academic achievement in high school students and identified the demographic characteristics associated with these three elements. This study also aimed to identify the percentage of variance in loneliness accounted for by social media use and GPA. Participants were 345…

  9. Emotional Intelligence and Academic Achievement of High School Students in Kanyakumari District

    ERIC Educational Resources Information Center

    Lawrence, A. S. Arul; Deepa, T.

    2013-01-01

    The objective of the study is to find the significant relationship between emotional intelligence and academic achievement of high school students with reference to the background variables. Survey method was employed. Two tools are used in this study namely self-made Trait Emotional Intelligence Questionnaire Short Form (TEIQue SF) and the…

  10. Conflicts and Communication between High-Achieving Chinese American Adolescents and Their Parents

    ERIC Educational Resources Information Center

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent…

  11. Comparing Computer Game and Traditional Lecture Using Experience Ratings from High and Low Achieving Students

    ERIC Educational Resources Information Center

    Grimley, Michael; Green, Richard; Nilsen, Trond; Thompson, David

    2012-01-01

    Computer games are purported to be effective instructional tools that enhance motivation and improve engagement. The aim of this study was to investigate how tertiary student experiences change when instruction was computer game based compared to lecture based, and whether experiences differed between high and low achieving students. Participants…

  12. New Counter-School Cultures: Female Students' Drug Use at a High-Achieving Secondary School

    ERIC Educational Resources Information Center

    Fletcher, Adam; Bonell, Chris; Rhodes, Tim

    2009-01-01

    We draw on case-study research at a high-achieving secondary school in London to illustrate how school experiences may influence drug use and reproduce inequalities in reconstructed ways in late modernity. Qualitative data were collected through semi-structured interviews with students and teachers, and observations. We focus in particular on the…

  13. How High-Achieving African American Undergraduate Men Negotiate Cultural Challenges at a Predominantly White Institution

    ERIC Educational Resources Information Center

    Bradley, Elva Elaine

    2010-01-01

    In this study I examine the manner in which high-achieving African American undergraduate men negotiate cultural challenges in a predominantly White institution (PWI). Cultural theory underpins the conceptual framework of this case study. Basing the study in cultural theory provided a lens through which to view the lived experiences of the twenty…

  14. Examining the Relationships between Math Achievement and the Resiliency of High School Seniors

    ERIC Educational Resources Information Center

    Chadwick, Mona

    2009-01-01

    The purpose of this research is to explore the relationship between math achievement and student resiliency among high school seniors. Seniors from nine school districts in southeast Texas participated by answering a short demographic survey and the "Healthy Kids Resiliency Assessment" (Constantine & Benard, 2001). A total of 457 surveys were…

  15. An Exploratory Study Contrasting High- and Low-Achieving Students' Percent Word Problem Solving

    ERIC Educational Resources Information Center

    Jitendra, Asha K.; Star, Jon R.

    2012-01-01

    This study evaluated whether schema-based instruction (SBI), a promising method for teaching students to represent and solve mathematical word problems, impacted the learning of percent word problems. Of particular interest was the extent that SBI improved high- and low-achieving students' learning and to a lesser degree on the indirect effect of…

  16. High School Success: An Effective Intervention for Achievement and Dropout Prevention

    ERIC Educational Resources Information Center

    Lowder, Christopher Michael

    2012-01-01

    The purpose of this mixed-design study was to use quantitative and qualitative research to explore the effects of High School Success (a course for at-risk ninth graders) and its effectiveness on student achievement, attendance, and dropout prevention. The research questions address whether there is a significant difference between at-risk ninth…

  17. Obesity, High-Calorie Food Intake, and Academic Achievement Trends among U.S. School Children

    ERIC Educational Resources Information Center

    Li, Jian; O'Connell, Ann A.

    2012-01-01

    The authors investigated children's self-reported high-calorie food intake in Grade 5 and its relationship to trends in obesity status and academic achievement over the first 6 years of school. They used 3-level hierarchical linear models in the large-scale database (the Early Childhood Longitudinal Study--Kindergarten Cohort). Findings indicated…

  18. The Effects of Alcohol Use on Academic Achievement in High School

    ERIC Educational Resources Information Center

    Balsa, Ana I.; Giuliano, Laura M.; French, Michael T.

    2011-01-01

    This paper examines the effects of alcohol use on high school students' quality of learning. We estimate fixed-effects models using data from the National Longitudinal Study of Adolescent Health. Our primary measure of academic achievement is the student's grade point average (GPA) abstracted from official school transcripts. We find that…

  19. Confronting the Universal Disbelief that Poor Children Can Achieve at High Levels

    ERIC Educational Resources Information Center

    Kelleher, Paul

    2006-01-01

    In her first year as superintendent of the Atlanta Public Schools, Beverly Hall encountered what she describes as the nearly universal disbelief that poor children of color can achieve high levels of learning. This chapter recounts how she confronted this and other obstacles and challenges as the new leader of the Atlanta Public Schools. Hall is…

  20. Faculty Perceptions of High-Achieving Male Collegians: A Critical Race Theory Analysis

    ERIC Educational Resources Information Center

    Comeaux, Eddie

    2013-01-01

    Critical race theory was employed as an interpretive framework to explore faculty perceptions of the academic accomplishments of high-achieving Black and White male collegians. Using photo elicitation methodology, faculty participants responded to a randomly assigned photograph of and vignette about either a Black or White male student. While most…

  1. A Study of the Impact of Block Scheduling on Student Academic Achievement in Public High Schools

    ERIC Educational Resources Information Center

    Norton, Mary Kay

    2010-01-01

    The number of public high schools implementing a semester 4 x 4 block scheduling design within the state of South Carolina has tripled since 2005. However, minimal local research has been conducted regarding the impact of block scheduling on student academic achievement. The purpose of this study was to determine if significant differences exist…

  2. Antecedent and Concurrent Psychosocial Skills That Support High Levels of Achievement within Talent Domains

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula; Subotnik, Rena F.; Worrell, Frank C.

    2015-01-01

    Motivation and emotional regulation are important for the sustained focused study and practice required for high levels of achievement and creative productivity in adulthood. Using the talent development model proposed by the authors as a framework, the authors discuss several important psychosocial skills based on the psychological research…

  3. The Relationship between Student Attendance and Academic Achievement in a Selected South Dakota High School

    ERIC Educational Resources Information Center

    Johnke, Jennifer

    2013-01-01

    There is limited research available on the relationship between student attendance and academic achievement in secondary school. This quantitative, non-experimental study, conducted within a South Dakota high school of students in grades 9-12 during the years 2006-2012, examined the relationship between student attendance and academic achievement…

  4. Ugandan Immigrant Students' Perceptions of Barriers to Academic Achievement in American High Schools

    ERIC Educational Resources Information Center

    Ssekannyo, Denis

    2010-01-01

    In a world that is now a global village, enterprising individuals, especially from Third World countries, who make it to greener pastures do not leave their children behind. But with a long list of barriers to academic achievement associated with immigrant and minority students in American high schools, an understanding of the experiences and…

  5. Narrowing the Academic Achievement Gap among High School Latino Students through Parental Involvement

    ERIC Educational Resources Information Center

    Parry, Douglas L.

    2010-01-01

    The low academic achievement among Latino students in many inner city high schools leads to higher failure, dropout, and absenteeism rates, as well as lower standardized test scores and graduation rates. The purpose of this study was to explore whether Latino parental attitudes toward and perceptions, level of, and form of involvement may be…

  6. Being Labeled "Nerd": Factors that Influence the Social Acceptance of High-Achieving Students

    ERIC Educational Resources Information Center

    Rentzsch, Katrin; Schutz, Astrid; Schroder-Abe, Michela

    2011-01-01

    The present investigation addresses the question of whether certain factors can protect high-achieving students at risk for being labeled a nerd against devaluation. In 2 studies, 125 and 317 students from Grade 8 evaluated vignettes describing average students and students who were called "nerds." Results indicate that being modest about good…

  7. Students' High School Organizational Leadership Opportunities and Their Influences on Academic Achievement and Civic Participation

    ERIC Educational Resources Information Center

    Elemen, Jennifer E.

    2015-01-01

    The purpose of this quantitative study was to analyze high school leadership praxis for its inclusion of students in organizational leadership dialogue and decision-making and the influences of these factors on student achievement and civic participation. Survey questionnaire data were provided by 215 full-time enrolled undergraduate students from…

  8. High-Stakes Testing and Student Achievement: Does Accountability Pressure Increase Student Learning?

    ERIC Educational Resources Information Center

    Nichols, Sharon L.; Glass, Gene V.; Berliner, David C.

    2006-01-01

    This study examined the relationship between high-stakes testing pressure and student achievement across 25 states. Standardized portfolios were created for each study state. Each portfolio contained a range of documents that told the "story" of accountability implementation and impact in that state. Using the "law of comparative judgments," over…

  9. Further Evidence of an Engagement-Achievement Paradox among U.S. High School Students

    ERIC Educational Resources Information Center

    Shernoff, David J.; Schmidt, Jennifer A.

    2008-01-01

    Achievement, engagement, and students' quality of experience were compared by racial and ethnic group in a sample of students (N = 586) drawn from 13 high schools with diverse ethnic and socioeconomic student populations. Using the Experience Sampling Method (ESM), 3,529 samples of classroom experiences were analyzed along with self-reported…

  10. Ego Identity, Cognitive Ability, and Academic Achievement: Variances, Relationships, and Gender Differences Among High School Sophomores.

    ERIC Educational Resources Information Center

    Wrabel, Thomas J.

    This study examined the contributions of cognitive quantitative ability, cognitive verbal ability, normed test achievement and grade point average to the ego identity of 202 high school sophomores. The instrumentation used in this study was as follows: (1) Rasmussen Ego Identity Scale: Revised Short Form; (2) The 3-R's Abilities and Achievement…

  11. Integrating Economic and Social Policy: Good Practices from High-Achieving Countries. Innocenti Working Papers.

    ERIC Educational Resources Information Center

    Mehrotra, Santosh

    This paper examines the successes of 10 "high achievers," countries with social indicators far higher than might be expected, given their national wealth, pulling together the lessons learned for social policy in the developing world. The 10 countries identified are Costa Rica, Cuba, Barbados, Botswana, Zimbabwe, Mauritius, Kerala, Sri Lanka,…

  12. The Relationship between Student Achievement and Charter High Schools in Washington, DC

    ERIC Educational Resources Information Center

    Pardo, Alexandra

    2013-01-01

    This study was designed to determine if differences in student achievement existed between traditional public and charter high schools in the District of Columbia. The study examined student outcomes on the standardized state test in reading and math from 2006 to 2010 utilizing descriptive statistics, crosstab analysis, chi-square tests…

  13. Experiencing More Mathematics Anxiety than Expected? Contrasting Trait and State Anxiety in High Achieving Students

    ERIC Educational Resources Information Center

    Roos, A.-L.; Bieg, M.; Goetz, T.; Frenzel, A. C.; Taxer, J.; Zeidner, M.

    2015-01-01

    This study examined mathematics anxiety among high and low achieving students (N = 237, grades 9 and 10) by contrasting trait (habitual) and state (momentary) assessments of anxiety. Previous studies have found that trait anxiety measures are typically rated higher than state measures. Furthermore, the academic self-concept has been identified to…

  14. Actively Closing the Gap? Social Class, Organized Activities, and Academic Achievement in High School

    ERIC Educational Resources Information Center

    Morris, David S.

    2015-01-01

    Participation in Organized Activities (OA) is associated with positive behavioral and developmental outcomes in children. However, less is known about how particular aspects of participation affect the academic achievement of high school students from different social class positions. Using the Education Longitudinal Study of 2002, this study…

  15. The College-Choice Process of High Achieving Freshmen: A Comparative Case Study

    ERIC Educational Resources Information Center

    Dale, Amanda

    2010-01-01

    The purpose of this study was to examine the college-choice process of high achieving students. Employing current literature and previous research, it combined current models of college choice and the influential factors identified throughout the literature while utilizing the concept of bounded rationality to create a conceptual framework to…

  16. Communication Satisfaction, Organizational Citizenship Behavior and the Relationship to Student Achievement in High Schools

    ERIC Educational Resources Information Center

    Blanchard, Gayle A.

    2012-01-01

    This study used a correlational design that allowed the researcher to examine the relationship among communication satisfaction, organizational citizenship behaviors (OCB) and student achievement. High school teachers were surveyed from a convenience sample of 12 school districts in Arizona. Established instruments were used to survey…

  17. One-to-One Computing and Student Achievement in Ohio High Schools

    ERIC Educational Resources Information Center

    Williams, Nancy L.; Larwin, Karen H.

    2016-01-01

    This study explores the impact of one-to-one computing on student achievement in Ohio high schools as measured by performance on the Ohio Graduation Test (OGT). The sample included 24 treatment schools that were individually paired with a similar control school. An interrupted time series methodology was deployed to examine OGT data over a period…

  18. Turkish High School Students' Biology Achievement in Relation to Academic Self-Regulation

    ERIC Educational Resources Information Center

    Yumusak, Necmettin; Sungur, Semra; Cakiroglu, Jale

    2007-01-01

    This study aimed at investigating the contribution of motivational beliefs, cognitive, and metacognitive strategy use to Turkish high school students' achievement in biology. In order to investigate the specified purpose of the study, 519 tenth-grade students were administered the Motivated Strategies for Learning Questionnaire (Pintrich, Smith,…

  19. Moving beyond Time and Choice: Challenge, Motivation and Achievement during Independent Reading in High School

    ERIC Educational Resources Information Center

    Perks, Kevin

    2010-01-01

    In response to concerns about poor engagement and achievement in reading, some high schools have implemented independent reading programs to give students time to read self-selected texts during school. Some schools are also adopting the Lexile framework as a tool for matching readers with challenging texts in order to improve reading motivation…

  20. The Impact of Reading Success Academy on High School Reading Achievement

    ERIC Educational Resources Information Center

    Burlison, Kelly; Chave, Josh

    2014-01-01

    The study explores the effectiveness of the Reading Success Academy on the reading achievement of the selected group of ninth-grade students in a comprehensive high school. We examine in what ways the Reading Success Academy may improve the reading proficiency rates and amount of reading growth of ninth-grade students. The results indicate that…

  1. Effect of Textbook Readability on Student Achievement in High School Chemistry.

    ERIC Educational Resources Information Center

    Rapp, D. Neil

    2001-01-01

    Notes the readability level of many high school chemistry textbooks is far above students' reading levels. Conducts two separate studies, making every effort to keep the two classes as similar as possible in all aspects except text. Finds strong evidence that changing the chemistry textbook resulted in an increase in student achievement. Suggests…

  2. Organizational Practices of High-Achieving Rural School Districts in California's San Joaquin Valley

    ERIC Educational Resources Information Center

    Doerksen, Amanda López; Wise, Donald

    2016-01-01

    For over 25 years, researchers have identified "best practices" used by high-achieving school districts. However, little research exists regarding rural school systems, making it difficult to determine whether the best practices identified are relevant within this context. This study filled a void in research by focusing on the…

  3. Cognitive Abilities and Motivational Processes in High School Students' Situational Engagement and Achievement in Science.

    ERIC Educational Resources Information Center

    Lau, Shun; Roeser, Robert W.

    2002-01-01

    Building on R. Snow's two pathways to achievement outcomes (1989), examined how cognitive and motivational factors associated with the performance and commitment pathways respectively contributed to prediction of outcomes in science for 491 high school students. Results are consistent with Snow's conjecture that factors related to both pathways…

  4. Balancing Dreams and Realities: The College Choice Process for High-Achieving Latinas

    ERIC Educational Resources Information Center

    Hernández, Ebelia

    2015-01-01

    This study's narratives of 17 high-achieving Latinas revealed how their college choice was a constant balancing of individual and family expectations, being "close, but far enough away," and "getting your money's worth." With the use of critical race theory, further analysis revealed the influence of "familismo" on…

  5. Measuring the Outliers: An Introduction to Out-of-Level Testing with High-Achieving Students

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; Warne, Russell T.

    2015-01-01

    Out-of-level testing is an underused strategy for addressing the needs of students who score in the extremes, and when used wisely, it could provide educators with a much more accurate picture of what students know. Out-of-level testing has been shown to be an effective assessment strategy with high-achieving students; however, out-of-level…

  6. The Relationship between Illinois School District Superintendent Longevity and High School Student Achievement

    ERIC Educational Resources Information Center

    Libka, Robert J.

    2012-01-01

    Frequent changes in school district superintendents may be having a detrimental impact on student achievement. Rapid changes in leadership today parallel the present (NCLB) era of high stakes state assessments. The goal of the study was to provide correlation research that would have a positive effect on school district management, superintendent…

  7. Teachers and Student Achievement in the Chicago Public High Schools. WP 2002-28. Revised

    ERIC Educational Resources Information Center

    Aaronson, Daniel; Barrow, Lisa; Sander, William

    2003-01-01

    Using unique administrative data on Chicago public high school students and their teachers, we are able to estimate the importance of teachers on student mathematical achievement. We find that teachers are educationally and statistically important. To be sure, sampling variation and other measurement issues can strongly influence estimates of…

  8. School Board-Superintendent Relations in Support of High Student Achievement. The Informed Educator Series.

    ERIC Educational Resources Information Center

    Porch, Stephanie; Protheroe, Nancy

    The context of school district governance is changing and becoming more complex. The individual roles of school board members and superintendents, and the relationship between school board members and superintendents are becoming increasingly important in light of the recent mandates for high student achievement. This brief looks at issues…

  9. The Transition Experiences of High-Achieving, Low-Income Undergraduates in an Elite College Environment

    ERIC Educational Resources Information Center

    McLoughlin, Paul J., II

    2012-01-01

    This hermeneutic phenomenological study describes the lived experiences of high-achieving, low-income undergraduates and their transition into a college environment historically reserved for wealthy students. The results of this study indicate that these students are flourishing in full need-based financial aid programs as a result of their own…

  10. What Attracts High-Achieving Socioeconomically Disadvantaged Students to the Physical Sciences and Engineering?

    ERIC Educational Resources Information Center

    Conrad, Sarah; Canetto, Silvia Sara; MacPhee, David; Farro, Samantha

    2009-01-01

    Socioeconomically disadvantaged (SED) students are less likely to major in physical sciences or engineering. To guide recruitment and retention of a diversity of talent, this study examined what attracts high-achieving SED students to these fields. Participants were 50 undergraduates majoring in physical sciences or engineering enrolled in the…

  11. Raising Reading Achievement in Middle and High Schools: Five Simple-to-Follow Strategies. Second Edition

    ERIC Educational Resources Information Center

    McEwan, Elaine K.

    2006-01-01

    In response to the No Child Left Behind Act (NCLB), raising literacy levels in secondary schools has taken on a new urgency. Recognized literacy author, Elaine K. McEwan, focuses her revised second edition on enhancing the "five big ideas" for raising reading achievement with seven cognitive strategies of highly effective readers and more than…

  12. School Factors Related to Reading Achievement in Rural Schools with and without High Poverty

    ERIC Educational Resources Information Center

    Miller, Seth W.

    2013-01-01

    This quantitative study identified how rural schools differ on five school-level factors related to student achievement according to their performance on Grade 3 reading. Through use of a MANOVA test, it was shown that principals of high-poverty rural schools that made AYP in Grade 3 reading reported significantly higher levels of guaranteed and…

  13. Brain Structure and Resting-State Functional Connectivity in University Professors with High Academic Achievement

    ERIC Educational Resources Information Center

    Li, Weiwei; Yang, Wenjing; Li, Wenfu; Li, Yadan; Wei, Dongtao; Li, Huimin; Qiu, Jiang; Zhang, Qinglin

    2015-01-01

    Creative persons play an important role in technical innovation and social progress. There is little research on the neural correlates with researchers with high academic achievement. We used a combined structural (regional gray matter volume, rGMV) and functional (resting-state functional connectivity analysis, rsFC) approach to examine the…

  14. Consequences of the Confucian Culture: High Achievement but Negative Psychological Attributes?

    ERIC Educational Resources Information Center

    Ho, Irene T.; Hau, Kit-Tai

    2010-01-01

    In "Unforgiving Confucian culture: A breeding ground for high academic achievement, test anxiety and self-doubt?" Stankov (in press) provides three reasons for caution against over-glorifying the academic excellence of Confucian Asian learners, namely that it may lead to a reluctance to change their rote learning approach which is not conducive to…

  15. Academic Identity Status, Goal Orientation, and Academic Achievement among High School Students

    ERIC Educational Resources Information Center

    Hejazi, Elaheh; Lavasani, Masoud Gholamali; Amani, Habib; Was, Christopher A.

    2012-01-01

    The aim of the present study was to determine the relationship between academic identity status, goal orientations and academic achievement. 301 first year high school students completed the Academic Identity Measure and Goal Orientation Questionnaire. The average of 10 exam scores in the final semester was used as an index of academic…

  16. Test Results of the Luminosity Monitors for the LHC

    SciTech Connect

    Beche, J.F.; Byrd, J. M.; Doolittle, L.; Manfredi, P. F.; Matis, H. S.; Monroy, M.; Ratti, A.; Stezelberger, T.; Stiller, J.; Turner, W.; Yaver, H.; Drees, A.; Bravin, E.

    2009-05-04

    The Luminosity Monitor for the LHC has been built at LBNL and will be operational in the LHC during the upcoming run. The device, a gas ionization chamber, is installed in the high luminosity regions (those dedicated to the ATLAS and CMS experiments) and capable to resolve bunch-by-bunch luminosity as well as survive extreme levels of radiation. During the experimental R&D phase of its design, a prototype of this detector has been tested extensively at the ALS, in RHIC as well as in the SPS. Results of these experiments are presented here.

  17. Course Syllabi: High Expectations...High Achievement. Social Studies (and) History.

    ERIC Educational Resources Information Center

    Murray State Univ., KY.

    The document describes social studies and history courses offered in the junior high and senior high schools of Henry County, Tennessee. The syllabi were developed as part of a Teacher's Corps Demonstration Project. The overall objectives of the syllabi are to inform students and parents of the minimum competencies expected in social studies and…

  18. High Expectations--High Achievement on Literacy: "What Shall We Do in This Hangman's Hour?"

    ERIC Educational Resources Information Center

    Linnakyla, Pirjo

    Finland is a country of great expectations on literacy and literacy education. High expectations and demands have, however, a darker side. High expectations of society, parents, and teachers may have an effect on the students' self-esteem. The economic recession in the early 1990s strongly accelerated the change in literacy demands and…

  19. The Information Search Process of High, Middle, and Low Achieving High School Seniors.

    ERIC Educational Resources Information Center

    Kuhlthau, Carol C.

    Traditionally, library instruction has been based on the sources in the library and not on the process of seeking information. A new approach to library skills may be needed to enable students to become effective information users. This study investigated the information search process of 140 high school seniors in six high schools. Subjects were…

  20. Cultivating a Growth Mindset in Students at a High-Achieving High School

    ERIC Educational Resources Information Center

    Fegley, Alan D.

    2010-01-01

    The purpose of this EPP is to develop a plan for changing the mindset of a large number of Haddonfield Memorial High School (HMHS) students from a fixed mindset to a growth mindset. HMHS is by most conventional measures a high performing school. Typically 100% of the students graduate with 96% of the students attending two or four year colleges…

  1. No More 1s: High Expectations Can Lead to High Achievement

    ERIC Educational Resources Information Center

    Cervone, Laureen; DiMartino, Lisa; Kerr, Kris

    2010-01-01

    The school district in Middletown, New York, in the state's Orange County, today serves close to 7,000 students in four elementary schools, two middle schools, and one high school. The district is classified by the state in the highest of three Need-to-Resource-Capacity groups, an urban or suburban school district with high student needs in…

  2. XMM-NEWTON OBSERVATIONS REVEAL VERY HIGH X-RAY LUMINOSITY FROM THE CARBON-RICH WOLF-RAYET STAR WR 48a

    SciTech Connect

    Zhekov, Svetozar A.; Gagne, Marc; Skinner, Stephen L. E-mail: mgagne@wcupa.edu

    2011-01-20

    We present XMM-Newton observations of the dusty Wolf-Rayet (W-R) star WR 48a. This is the first detection of this object in X-rays. The XMM-Newton EPIC spectra are heavily absorbed and the presence of numerous strong emission lines indicates a thermal origin of the WR 48a X-ray emission, with dominant temperature components at kT{sub cool} {approx} 1 keV and kT{sub hot} {approx} 3 keV, the hotter component dominating the observed flux. No significant X-ray variability was detected on timescales {<=}1 day. Although the distance to WR 48a is uncertain, if it is physically associated with Open clusters Danks 1 and 2 at d {approx}4 kpc, then the resultant X-ray luminosity L{sub X}{approx} 10{sup 35} erg s{sup -1} makes it the most X-ray luminous W-R star in the Galaxy detected so far, after the black hole candidate Cyg X-3. We assume the following scenarios as the most likely explanation for the X-ray properties of WR 48a: (1) colliding stellar winds in a wide WR+O binary system, or in a hierarchical triple system with non-degenerate stellar components and (2) accretion shocks from the WR 48a wind onto a close companion (possibly a neutron star). More specific information about WR 48a and its wind properties will be needed to distinguish between the above possibilities.

  3. Reduction of beta* and increase of luminosity at RHIC

    SciTech Connect

    Pilat,F.; Bai, M.; Bruno, D.; Cameron, P.; Della Penna, A.; Drees, A.; Litvinenko, V.; Luo, Y.; Malitsky, N.; Marr, G.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.

    2009-05-04

    The reduction of {beta}* beyond the 1m design value at RHIC has been consistently achieved over the last 6 years of RHIC operations, resulting in an increase of luminosity for different running modes and species. During the recent 2007-08 deuteron-gold run the reduction to 0.70 from the design 1m achieved a 30% increase in delivered luminosity. The key ingredients allowing the reduction have been the capability of efficiently developing ramps with tune and coupling feedback, orbit corrections on the ramp, and collimation, to minimize beam losses in the final focus triplets, the main aperture limitations for the collision optics. We will describe the operational strategy used to reduce the {beta}*, at first squeezing the beam at store, to test feasibility, followed by the operationally preferred option of squeezing the beam during acceleration, and the resulting luminosity increase. We will conclude with future plans for the beta squeeze.

  4. Achieving highly dispersed nanofibres at high loading in carbon nanofibre-metal composites

    NASA Astrophysics Data System (ADS)

    Kang, Jianli; Nash, Philip; Li, Jiajun; Shi, Chunsheng; Zhao, Naiqin

    2009-06-01

    In order to tap into the advantages of the properties of carbon nanotubes (CNTs) or carbon nanofibres (CNFs) in composites, the high dispersion of CNTs (or CNFs) and strong interfacial bonding are the key issues which are still challenging. In the current work, a novel approach, consisting of in situ synthesis of CNFs within the Cu powders and mixing Cu ions with the in situ CNF(Ni/Y)-Cu composite powders in a solvent, was developed to highly disperse CNFs in a Cu matrix. The composite, produced by vacuum hot pressing, shows extremely high strength, 3.6 times more than that of the matrix material alone. It is worth mentioning that this method can disperse CNFs at high loading in a metal matrix, inferring good potential for applications, such as electronic packaging materials.

  5. Modeling stability of growth between mathematics and science achievement during middle and high school.

    PubMed

    Ma, Xin; Ma, Lingling

    2004-04-01

    In this study, the authors introduced a multivariate multilevel model to estimate the consistency among students and schools in the rates of growth between mathematics and science achievement during the entire middle and high school years with data from the Longitudinal Study of American Youth (LSAY). There was no evident consistency in the rates of growth between mathematics and science achievement among students, and this inconsistency was not much influenced by student characteristics and school characteristics. However, there was evident consistency in the average rates of growth between mathematics and science achievement among schools, and this consistency was influenced by student characteristics and school characteristics. Major school-level variables associated with parental involvement did not show any significant impacts on consistency among either students or schools. Results call for educational policies that promote collaboration between mathematics and science departments or teachers.

  6. Relationship of constructivist learning environment to student attitudes and achievement in high school mathematics and science

    NASA Astrophysics Data System (ADS)

    Dethlefs, Theresa Marie

    This study investigated the relationship of constructivist learning environment and standards-based teaching practices to student achievement and attitudes (self-efficacy, intrinsic value, and learning strategies) in Algebra and Biology. Further, these relationships were examined as a function of student gender and prior achievement. A purposive sample of 804 high school students enrolled in Biology I, Algebra I, or Advanced Algebra was selected for inclusion in this study. Although the dimensions of constructivist learning environment that contributed to predicting student achievement and attitudes varied by content area and criterion, the results of the present study generally provide strong support for a positive relationship between constructivist learning environment and student attitudes, but little support for a direct relationship to student achievement. Teacher reports of overall constructivist learning environment were not correlated with achievement or attitudes. Observer reports of constructivist learning environment were correlated with student intrinsic value and learning strategies. Student reports of constructivist learning environment were correlated with all three attitude measures. Multiple regression findings showed that neither overall constructivist learning environment nor standards-based teaching practices predicted achievement in any of the content areas. Overall constructivist learning environment and standards-based teaching practices were significant positive predictors of student intrinsic value and learning strategies in all three content areas, after controlling for student and classroom demographic variables. Overall constructivist learning environment and standards-based teaching practices were also significant positive predictors of self-efficacy in Algebra 1. In addition, standards-based teaching practices was a significant positive predictor of student self-efficacy in Biology. No specific dimensions of constructivist learning

  7. The role of chronotype, gender, test anxiety, and conscientiousness in academic achievement of high school students.

    PubMed

    Rahafar, Arash; Maghsudloo, Mahdis; Farhangnia, Sajedeh; Vollmer, Christian; Randler, Christoph

    2016-01-01

    Previous findings have demonstrated that chronotype (morningness/intermediate/eveningness) is correlated with cognitive functions, that is, people show higher mental performance when they do a test at their preferred time of day. Empirical studies found a relationship between morningness and higher learning achievement at school and university. However, only a few of them controlled for other moderating and mediating variables. In this study, we included chronotype, gender, conscientiousness and test anxiety in a structural equation model (SEM) with grade point average (GPA) as academic achievement outcome. Participants were 158 high school students and results revealed that boys and girls differed in GPA and test anxiety significantly, with girls reporting better grades and higher test anxiety. Moreover, there was a positive correlation between conscientiousness and GPA (r = 0.17) and morningness (r = 0.29), respectively, and a negative correlation between conscientiousness and test anxiety (r = -0.22). The SEM demonstrated that gender was the strongest predictor of academic achievement. Lower test anxiety predicted higher GPA in girls but not in boys. Additionally, chronotype as moderator revealed a significant association between gender and GPA for evening types and intermediate types, while intermediate types showed a significant relationship between test anxiety and GPA. Our results suggest that gender is an essential predictor of academic achievement even stronger than low or absent test anxiety. Future studies are needed to explore how gender and chronotype act together in a longitudinal panel design and how chronotype is mediated by conscientiousness in the prediction of academic achievement.

  8. High fat diet promotes achievement of peak bone mass in young rats

    SciTech Connect

    Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T.; Mittal, Monika; Chattopadhyay, Naibedya; Wani, Mohan R.; Bhat, Manoj Kumar

    2014-12-05

    Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

  9. Achievement Motivation of the High School Students: A Case Study among Different Communities of Goalpara District of Assam

    ERIC Educational Resources Information Center

    Sarangi, C.

    2015-01-01

    Achievement motivation is a consistent striving force of an individual to achieve success to a certain standard of excellence in competing situation. In this study an attempt was made to study the effect of achievement motivation on the academic achievement of the high school students of tribal and non tribal communities in relation to their sex…

  10. A clumpy stellar wind and luminosity-dependent cyclotron line revealed by the first Suzaku observation of the high-mass X-ray binary 4U 1538–522

    SciTech Connect

    Hemphill, Paul B.; Rothschild, Richard E.; Markowitz, Alex; Fürst, Felix; Pottschmidt, Katja; Wilms, Jörn

    2014-09-01

    We present results from the first Suzaku observation of the high-mass X-ray binary 4U 1538–522. The broadband spectral coverage of Suzaku allows for a detailed spectral analysis, characterizing the cyclotron resonance scattering feature at 23.0 ± 0.4 keV and the iron Kα line at 6.426 ± 0.008 keV, as well as placing limits on the strengths of the iron Kβ line and the iron K edge. We track the evolution of the spectral parameters both in time and in luminosity, notably finding a significant positive correlation between cyclotron line energy and luminosity. A dip and spike in the light curve is shown to be associated with an order-of-magnitude increase in column density along the line of sight, as well as significant variation in the underlying continuum, implying the accretion of a overdense region of a clumpy stellar wind. We also present a phase-resolved analysis, with most spectral parameters of interest showing significant variation with phase. Notably, both the cyclotron line energy and the iron Kα line intensity vary significantly with phase, with the iron line intensity significantly out of phase with the pulse profile. We discuss the implications of these findings in the context of recent work in the areas of accretion column physics and cyclotron resonance scattering feature formation.

  11. How One Historically Underperforming Rural and Highly Diverse High School Achieved a Successful Turnaround

    ERIC Educational Resources Information Center

    Maxwell, Gerri M.; Huggins, Kristin S.; Scheurich, James J.

    2010-01-01

    "Central High School," a rural school composed largely of students of color from low income homes, experienced a quick, remarkable turnaround of student academic success, measured by State and Federal accountability standards. This turnaround began with an external restructuring grant initiative that required a state-approved external consultant.…

  12. A general strategy to achieve ultra-high gene transfection efficiency using lipid-nanoparticle composites.

    PubMed

    Vankayala, Raviraj; Chiang, Chi-Shiun; Chao, Jui-I; Yuan, Chiun-Jye; Lin, Shyr-Yeu; Hwang, Kuo Chu

    2014-09-01

    Gene therapy provides a new hope for previously "incurable" diseases. Low gene transfection efficiency, however, is the bottle-neck to the success of gene therapy. It is very challenging to develop non-viral nanocarriers to achieve ultra-high gene transfection efficiencies. Herein, we report a novel design of "tight binding-but-detachable" lipid-nanoparticle composite to achieve ultrahigh gene transfection efficiencies of 60∼82%, approaching the best value (∼90%) obtained using viral vectors. We show that Fe@CNPs nanoparticles coated with LP-2000 lipid molecules can be used as gene carriers to achieve ultra-high (60-80%) gene transfection efficiencies in HeLa, U-87MG, and TRAMP-C1 cells. In contrast, Fe@CNPs having surface-covalently bound N,N,N-trimethyl-N-2-methacryloxyethyl ammonium chloride (TMAEA) oligomers can only achieve low (23-28%) gene transfection efficiencies. Similarly ultrahigh gene transfection/expression was also observed in zebrafish model using lipid-coated Fe@CNPs as gene carriers. Evidences for tight binding and detachability of DNA from lipid-nanoparticle nanocarriers will be presented. PMID:24973297

  13. A general strategy to achieve ultra-high gene transfection efficiency using lipid-nanoparticle composites.

    PubMed

    Vankayala, Raviraj; Chiang, Chi-Shiun; Chao, Jui-I; Yuan, Chiun-Jye; Lin, Shyr-Yeu; Hwang, Kuo Chu

    2014-09-01

    Gene therapy provides a new hope for previously "incurable" diseases. Low gene transfection efficiency, however, is the bottle-neck to the success of gene therapy. It is very challenging to develop non-viral nanocarriers to achieve ultra-high gene transfection efficiencies. Herein, we report a novel design of "tight binding-but-detachable" lipid-nanoparticle composite to achieve ultrahigh gene transfection efficiencies of 60∼82%, approaching the best value (∼90%) obtained using viral vectors. We show that Fe@CNPs nanoparticles coated with LP-2000 lipid molecules can be used as gene carriers to achieve ultra-high (60-80%) gene transfection efficiencies in HeLa, U-87MG, and TRAMP-C1 cells. In contrast, Fe@CNPs having surface-covalently bound N,N,N-trimethyl-N-2-methacryloxyethyl ammonium chloride (TMAEA) oligomers can only achieve low (23-28%) gene transfection efficiencies. Similarly ultrahigh gene transfection/expression was also observed in zebrafish model using lipid-coated Fe@CNPs as gene carriers. Evidences for tight binding and detachability of DNA from lipid-nanoparticle nanocarriers will be presented.

  14. Pin-Hole Luminosity Monitor with Feedback

    NASA Astrophysics Data System (ADS)

    Norem, James H.; Spencer, James E.

    Previously, the generalized luminosity { L} was defined and calculated for all incident channels based on an NLC e+e- design. Alternatives were then considered to improve the differing beam-beam effects in the e-e-, eγ and γγ channels. Regardless of the channel, there was a large flux of outgoing, high energy photons that were produced from the beam-beam interaction e.g. beamstrahlung that needs to be disposed of and whose flux depended on { L}. One approach to this problem is to consider it a resource and attempt to take advantage of it by disposing of these straight-ahead photons in more useful ways than simply dumping them. While there are many options for monitoring the luminosity, any method that allows feedback and optimization in real time and in a non-intercepting and non-interfering way during normal data taking is extremely important - especially if it provides other capabilities such as high resolution tuning of spot sizes and can be used for all incident channels without essential modifications to their setup. Our "pin-hole" camera appears to be such a device if it can be made to work with high energy photons in ways that are compatible with the many other constraints and demands on space around the interaction region. The basis for using this method is that it has, in principle, the inherent resolution and bandwidth to monitor the very small spot sizes and their stabilities that are required for very high, integrated luminosity. While there are many possible, simultaneous uses of these outgoing photon beams, we limit our discussion to a single, blind, proof-of-principle experiment that was done on the FFTB line at SLAC to certify the concept of a camera obscura for high energy photons.

  15. Does the obscured AGN fraction really depend on luminosity?

    NASA Astrophysics Data System (ADS)

    Sazonov, S.; Churazov, E.; Krivonos, R.

    2015-12-01

    We use a sample of 151 local non-blazar active galactic nuclei (AGN) selected from the INTEGRAL all-sky hard X-ray survey to investigate if the observed declining trend of the fraction of obscured (i.e. showing X-ray absorption) AGN with increasing luminosity is mostly an intrinsic or selection effect. Using a torus-obscuration model, we demonstrate that in addition to negative bias, due to absorption in the torus, in finding obscured AGN in hard X-ray flux-limited surveys, there is also positive bias in finding unobscured AGN, due to Compton reflection in the torus. These biases can be even stronger taking into account plausible intrinsic collimation of hard X-ray emission along the axis of the obscuring torus. Given the AGN luminosity function, which steepens at high luminosities, these observational biases lead to a decreasing observed fraction of obscured AGN with increasing luminosity even if this fraction has no intrinsic luminosity dependence. We find that if the central hard X-ray source in AGN is isotropic, the intrinsic (i.e. corrected for biases) obscured AGN fraction still shows a declining trend with luminosity, although the intrinsic obscured fraction is significantly larger than the observed one: the actual fraction is larger than ˜85 per cent at L ≲ 1042.5 erg s-1 (17-60 keV), and decreases to ≲60 per cent at L ≳ 1044 erg s-1. In terms of the half-opening angle θ of an obscuring torus, this implies that θ ≲ 30° in lower luminosity AGN, and θ ≳ 45° in higher luminosity ones. If, however, the emission from the central supermassive black hole is collimated as dL/dΩ ∝ cos α, the intrinsic dependence of the obscured AGN fraction is consistent with a luminosity-independent torus half-opening angle θ ˜ 30°.

  16. Luminosities for Final Flash Stars

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth; Joyce, Richard; Lebzelter, Thomas

    2010-08-01

    A brief yet common evolutionary process is a post-AGB final episode of helium shell burning. This occurs after a low mass star has ejected a planetary nebula and has started on the white dwarf track. Seven stars are now classified with varying degrees of certainty as one of these ``final flash'' objects. Two of these have actually been observed to eject a shell of gas first as a pseudo-photosphere and then as a thick dust envelope. The dust envelopes are expanding at ~100 km s^-1. We propose AO imaging of the circumstellar shells to measure changes from images recorded a decade or more ago. From these changes we will determine geometric parallaxes and hence luminosities. The luminosity will be compared to stellar evolution models. In an additional challenge to models we will calibrate the He I emission line flux and through this the mass loss rate from the fast stellar wind.

  17. Luminosity monitor for the venus detector at TRISTAN

    NASA Astrophysics Data System (ADS)

    Saito, Hitoshi; Chiba, Masami; Fukui, Toru; Hirose, Tachishige; Shirakura, Hatsuo; Watanabe, Takashi; Takasaki, Fumihiko

    1988-07-01

    We constructed a luminosity monitor of the lead-scintillator sandwich type for the VENUS detector at the e+e- collider TRISTAN. Photomultiplier tubes with transmissive mesh dynodes could be operated fairly well in a high magnetic field and hence the readout optics system was considerably simplified. We present the performance of the luminosity monitor for e+e- collisions at √s = 50 and 52 GeV.

  18. Solar response to luminosity variations

    NASA Astrophysics Data System (ADS)

    Arendt, S.

    1990-08-01

    The connection between solar luminosity and magnetic fields is now well-established. Magnetic fields under the guise of sunspots and faculae enhance or suppress heat transfer through the solar surface, leading to changes in the total solar luminosity. This raises the question of the effect that such surface heat transfer perturbations have on the internal structure of the sun. The problem has been considered previously by Foukal and Spruit. Here, researchers generalize the calculation of Spruit, removing the assumption of a constant heat diffusivity coefficient by treating the full mixing length heat transfer expression. Further, they treat the surface conditions in a simpler manner, and show that the previous conclusions of Foukal and Spruit are unaffected by these modifications. The model shows that following the application of a step function emissivity change: a fraction 1 - D0 of the luminosity change relaxes away after approx. 50 days. This corresponds to the thermal diffusion time across the convection zone, adjusting to a value in correspondence with the surface change. In other words, the whole convection zone feels the perturbation on this timescale. The remaining fraction relaxes away on a timescale of 10 to the 5th power years, corresponding to the convective layer radiating away enough energy so that it can adjust to its new adiabat. These are the same results arrived at by Spruit and Foukal. For variations of sigma on timescales of 10 to 200 years, then, the only important relaxation is the 50 day one. If the amplitude of this relaxation is small, the luminosity follows the sigma variation.

  19. Solar Response to Luminosity Variations

    NASA Technical Reports Server (NTRS)

    Arendt, S.

    1990-01-01

    The connection between solar luminosity and magnetic fields is now well-established. Magnetic fields under the guise of sunspots and faculae enhance or suppress heat transfer through the solar surface, leading to changes in the total solar luminosity. This raises the question of the effect that such surface heat transfer perturbations have on the internal structure of the sun. The problem has been considered previously by Foukal and Spruit. Here, researchers generalize the calculation of Spruit, removing the assumption of a constant heat diffusivity coefficient by treating the full mixing length heat transfer expression. Further, they treat the surface conditions in a simpler manner, and show that the previous conclusions of Foukal and Spruit are unaffected by these modifications. The model shows that following the application of a step function emissivity change: a fraction 1 - D(sub 0) of the luminosity change relaxes away after approx. 50 days. This corresponds to the thermal diffusion time across the convection zone, adjusting to a value in correspondence with the surface change. In other words, the whole convection zone feels the perturbation on this timescale. The remaining fraction relaxes away on a timescale of 10 to the 5th power years, corresponding to the convective layer radiating away enough energy so that it can adjust to its new adiabat. These are the same results arrived at by Spruit and Foukal. For variations of sigma on timescales of 10 to 200 years, then, the only important relaxation is the 50 day one. If the amplitude of this relaxation is small, the luminosity follows the sigma variation.

  20. Solvent additive to achieve highly ordered nanostructural semicrystalline DPP copolymers: toward a high charge carrier mobility.

    PubMed

    An, Tae Kyu; Kang, Il; Yun, Hui-jun; Cha, Hyojung; Hwang, Jihun; Park, Seonuk; Kim, Jiye; Kim, Yu Jin; Chung, Dae Sung; Kwon, Soon-Ki; Kim, Yun-Hi; Park, Chan Eon

    2013-12-23

    A facile spin-coating method in which a small percentage of the solvent additive, 1-chloronaphthalene (CN), is found to increase the drying time during film deposition, is reported. The field-effect mobility of a PDPPDBTE film cast from a chloroform-CN mixed solution is 0.46 cm(2) V(-1) s(-1). The addition of CN to the chloroform solution facilitates the formation of highly crystalline polymer structures. PMID:24115273

  1. The luminosity function of quasars

    NASA Technical Reports Server (NTRS)

    Pei, Yichuan C.

    1995-01-01

    We propose a new evolutionary model for the optical luminosity function of quasars. Our analytical model is derived from fits to the empirical luminosity function estimated by Hartwick and Schade and Warren, Hewett, and Osmer on the basis of more than 1200 quasars over the range of redshifts 0 approximately less than z approximately less than 4.5. We find that the evolution of quasars over this entire redshift range can be well fitted by a Gaussian distribution, while the shape of the luminosity function can be well fitted by either a double power law or an exponential L(exp 1/4) law. The predicted number counts of quasars, as a function of either apparent magnitude or redshift, are fully consistent with the observed ones. Our model indicates that the evolution of quasars reaches its maximum at z approximately = 2.8 and declines at higher redshifts. An extrapolation of the evolution to z approximately greater than 4.5 implies that quasars may have started their cosmic fireworks at z(sub f) approximately = 5.2-5.5. Forthcoming surveys of quasars at these redshifts will be critical to constrain the epoch of quasar formation. All the results we derived are based on observed quasars and are therefore subject to the bias of obscuration by dust in damped Ly alpha systems. Future surveys of these absorption systems at z approximately greater than 3 will also be important if the formation epoch of quasars is to be known unambiguously.

  2. Challenges to achievement of metal sustainability in our high-tech society

    SciTech Connect

    Izatt, Reed M.; Izatt, Steven R.; Bruening, Ronald L.; Izatt, Neil; Moyer, Bruce A

    2014-01-01

    Achievement of sustainability in metal life cycles from mining of virgin ore to consumer and industrial devices to end-of-life products requires greatly increased recycling and improved processing of metals. Electronic and other high-tech products containing precious, toxic, and specialty metals usually have short lifetimes and low recycling rates. Products containing these metals generally are incinerated, discarded as waste in landfills, or dismantled in informal recycling using crude and environmentally irresponsible procedures. Low metal recycling rates coupled with increasing demand for products containing them necessitate increased mining with attendant environmental, health, energy, water, and carbon-footprint consequences. In this tutorial review, challenges to achieving metal sustainability in present high-tech society are presented; health, environmental, and economic incentives for various stakeholders to improve metal sustainability are discussed; a case for technical improvements in separations technology, especially employing molecular recognition, is given; and global consequences of continuing on the present path are examined.

  3. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.

    PubMed

    Krapohl, Eva; Rimfeld, Kaili; Shakeshaft, Nicholas G; Trzaskowski, Maciej; McMillan, Andrew; Pingault, Jean-Baptiste; Asbury, Kathryn; Harlaar, Nicole; Kovas, Yulia; Dale, Philip S; Plomin, Robert

    2014-10-21

    Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35-58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.

  4. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence

    PubMed Central

    Krapohl, Eva; Rimfeld, Kaili; Shakeshaft, Nicholas G.; Trzaskowski, Maciej; McMillan, Andrew; Pingault, Jean-Baptiste; Asbury, Kathryn; Harlaar, Nicole; Kovas, Yulia; Dale, Philip S.; Plomin, Robert

    2014-01-01

    Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35–58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. PMID:25288728

  5. High-fidelity simulation: Assessment of student nurses' team achievements of clinical judgment.

    PubMed

    Hallin, Karin; Bäckström, Britt; Häggström, Marie; Kristiansen, Lisbeth

    2016-07-01

    Nursing educators have the challenge of preparing nursing students to handle complex patient care situations in real life, but much remains unknown about the ability to make clinical judgments. In this study, high-fidelity simulation (HFS) was used at a Swedish university to find answers about pre-licensure nursing students' success in clinical judgment in terms of team ability and relationships with theoretical achievements, and personal and scenario circumstances. The matrix Lasater Clinical Judgment Rubric (LCJR) was used to analyze and score the students' ability in teams to notice, interpret and respond to complex care situations. Overall, the results showed the student teams in their first meeting with HFS in a complex care situation achieved low clinical judgment points; most teams were in the stages of Beginning and Developing. For attaining high team achievements the majority of the students in the team should theoretically be "high performance". Being observers and having HFS experience before nursing education was significant too. However, age, health care experience, and assistant nurse degrees were of secondary importance. Further research at universities regionally, nationally, and internationally is needed. PMID:27428686

  6. Nutrition and education. III. Educational achievement and food habits of Chilean elementary and high school graduates.

    PubMed

    Ivanovic, D; Vásquez, M; Aguayo, M; Ballester, D; Marambio, M; Zacarías, I

    1992-03-01

    The objective of this study was to correlate the educational achievement (EA) of Chilean elementary and high-school graduates with their food habits. For this purpose, a random sample of 550 schoolers from the Metropolitan Area of Santiago, Chile, graduating from elementary and high school (1:1) of both sexes (1:1), from public and private schools and from high, medium and low socioeconomic status (SES) (1:1:1), was selected. Food habits were determined through a specially designed questionnaire and defined as the frequency of consumption of the food groups, expressed as days per week. The EA was established through the Achievement Evaluation Program (AEP) and Academic Aptitude Test (AAT) in elementary-and high-school graduates-, respectively. Results revealed that EA was found significantly and positively correlated with the frequency of consumption of dairy products, meat products and eggs, in both elementary and high school graduates. A significant and inverse correlation between EA and the frequency of vegetables and fruits consumption was observed in both educational levels, and with miscellaneous products, only in elementary school graduates. Food habits explained 24.4% and 16.6% of the EA variance, in elementary and high school graduates, respectively. The frequency of consumption of dairy products was the independent variable with the greatest explanatory power in EA variance (approximately above 70% of the explained variance). These results are important to consider for educational planning focused on the School Feeding Program.

  7. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    NASA Astrophysics Data System (ADS)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  8. Dry Blending to Achieve Isotopic Dilution of Highly Enriched Uranium Oxide Materials

    SciTech Connect

    Henry, Roger Neil; Chipman, Nathan Alan; Rajamani, R. K.

    2001-04-01

    The end of the cold war produced large amounts of excess fissile materials in the United States and Russia. The Department of Energy has initiated numerous activities to focus on identifying material management strategies for disposition of these excess materials. To date, many of these planning strategies have included isotopic dilution of highly enriched uranium as a means of reducing the proliferation and safety risks. Isotopic dilution by dry blending highly enriched uranium with natural and/or depleted uranium has been identified as one non-aqueous method to achieve these risk (proliferation and criticality safety) reductions. This paper reviews the technology of dry blending as applied to free flowing oxide materials.

  9. Progress toward achieving high power and high efficiency semipolar LEDs and their characterization

    NASA Astrophysics Data System (ADS)

    Zhong, Hong

    Performance of current commercially available wurtzite nitride based light-emitting diodes (LEDs), grown along the polar (0001) c-plane orientation, is limited by the presence of polarization-related electric fields inside multi-quantum wells (MQWs). The discontinuities in both spontaneous and piezoelectric polarization at the heterointerfaces result in internal electric fields in the quantum wells. These electric fields cause carrier separation [quantum confined Stark effect (QCSE)] and reduce the radiative recombination rate within the quantum wells. One approach to reduce and possibly eliminate the polarization-related effects is to grow III-nitride devices on crystal planes that are inclined with respect to the c-axis, i.e., on semipolar planes. In this dissertation, metalorganic chemical vapor deposition (MOCVD) has been employed for the homoepitaxial growth of GaN based LEDs on semipolar orientations. As a consequence of growing on high-quality bulk GaN substrates, the LEDs have significantly reduced threading dislocation and stacking fault densities, resulting in remarkable improvements in EQE and output power. High efficiency semipolar (1011) violet-blue and blue LEDs have been demonstrated without any intentional effort to enhance the light extraction from those devices. Optimizations of epitaxial structures have led to increased output power and external quantum efficiency. A silicone encapsulated single quantum well blue LED with peak wavelength of 444 nm with output power of 24.3 mW, external quantum efficiency of 43% and luminous efficacy of 75 lm/W (with phosphorescent coating) at 20 mA has been demonstrated. Polarization fields in strained (1011) and (112¯2) InGaN quantum wells have been experimentally determined through bias-dependent optical studies. Our results show that the polarization field flips its direction in semipolar InGaN quantum wells with large inclination angles (i.e. around 60°). This suggests that there exists a polarization

  10. Heterogeneity in High Math Achievement across Schools: Evidence from the American Mathematics Competitions. NBER Working Paper No. 18277

    ERIC Educational Resources Information Center

    Ellison, Glenn; Swanson, Ashley

    2012-01-01

    This paper explores differences in the frequency with which students from different schools reach high levels of math achievement. Data from the American Mathematics Competitions is used to produce counts of high-scoring students from more than two thousand public, coeducational, non-magnet, non-charter U.S. high schools. High-achieving students…

  11. Acculturation, Social Support and Academic Achievement of Mexican and Mexican American High School Students: An Exploratory Study.

    ERIC Educational Resources Information Center

    Lopez, Eric J.; Ehly, Stewart; Garcia-Vasquez, Enedina

    2002-01-01

    Concern about the high dropout rate among Mexican American high school students promoted a study to investigate how acculturation and social support influence academic achievement. Students who were highly integrated and strongly bicultural tended to have higher academic achievement. Females tended to have high GPAs; males were slightly more…

  12. High performances CNTFETs achieved using CNT networks for selective gas sensing

    NASA Astrophysics Data System (ADS)

    Gorintin, Louis; Bondavalli, Paolo; Legagneux, Pierre; Pribat, Didier

    2009-08-01

    Our study deals with the utilization of carbon nanotubes networks based transistors with different metal electrodes for highly selective gas sensing. Indeed, carbon nanotubes networks can be used as semi conducting materials to achieve good performances transistors. These devices are extremely sensitive to the change of the Schottky barrier heights between Single Wall Carbon Nanotubes (SWCNTs) and drain/source metal electrodes: the gas adsorption creates an interfacial dipole that modifies the metal work function and so the bending and the height of the Schottky barrier at the contacts. Moreover each gas interacts specifically with each metal identifying a sort of electronic fingerprinting. Using airbrush technique for deposition, we have been able to achieve uniform random networks of carbon nanotubes suitable for large area applications and mass production such as fabrication of CNT based gas sensors. These networks enable us to achieve transistors with on/off ratio of more than 5 orders of magnitude. To reach these characteristics, the density of the CNT network has been adjusted in order to reach the percolation threshold only for semi-conducting nanotubes. These optimized devices have allowed us to tune the sensitivity (improving it) of our sensors for highly selective detection of DiMethyl-Methyl-Phosphonate (DMMP, a sarin stimulant), and even volatile drug precursors using Pd, Au and Mo electrodes.

  13. Strategies to achieve high-solids enzymatic hydrolysis of dilute-acid pretreated corn stover.

    PubMed

    Geng, Wenhui; Jin, Yongcan; Jameel, Hasan; Park, Sunkyu

    2015-01-01

    Three strategies were presented to achieve high solids loading while maximizing carbohydrate conversion, which are fed-batch, splitting/thickening, and clarifier processes. Enzymatic hydrolysis was performed at water insoluble solids (WIS) of 15% using washed dilute-acid pretreated corn stover. The carbohydrate concentration increased from 31.8 to 99.3g/L when the insoluble solids content increased from 5% to 15% WIS, while the final carbohydrate conversion was decreased from 78.4% to 73.2%. For the fed-batch process, a carbohydrate conversion efficiency of 76.8% was achieved when solid was split into 60:20:20 ratio, with all enzymes added first. For the splitting/thickening process, a carbohydrate conversion of 76.5% was realized when the filtrate was recycled to simulate a steady-state process. Lastly, the clarifier process was evaluated and the highest carbohydrate conversion of 81.4% was achieved. All of these results suggests the possibility of enzymatic hydrolysis at high solids to make the overall conversion cost-competitive.

  14. Academic achievement in the high school years: the changing role of school engagement.

    PubMed

    Chase, Paul A; Hilliard, Lacey J; Geldhof, G John; Warren, Daniel J A; Lerner, Richard M

    2014-06-01

    School engagement is an important theoretical and practical cornerstone to the promotion of academic accomplishments. This article used a tripartite-behavioral, emotional, and cognitive-model of school engagement to assess the relationship between school engagement and academic success among high school students, and to determine whether a reciprocal relationship exists between these constructs. Data were derived from 710 youth (69% female) who took part in Waves 6 through 8 (Grades 10 through 12) of the 4-H study of positive youth development. Longitudinal confirmatory factor analyses confirmed the invariance of the tripartite model of school engagement. Results of a structural equation model showed that the components of school engagement and academic achievement were mutually predictive and that these predictions varied from grade to grade. Future possibilities for evaluating the relationship between school engagement and academic achievement, as well as the implications for educational policy and practice, are discussed.

  15. The effects of modeling instruction on high school physics academic achievement

    NASA Astrophysics Data System (ADS)

    Wright, Tiffanie L.

    The purpose of this study was to explore whether Modeling Instruction, compared to traditional lecturing, is an effective instructional method to promote academic achievement in selected high school physics classes at a rural middle Tennessee high school. This study used an ex post facto , quasi-experimental research methodology. The independent variables in this study were the instructional methods of teaching. The treatment variable was Modeling Instruction and the control variable was traditional lecture instruction. The Treatment Group consisted of participants in Physical World Concepts who received Modeling Instruction. The Control Group consisted of participants in Physical Science who received traditional lecture instruction. The dependent variable was gains scores on the Force Concepts Inventory (FCI). The participants for this study were 133 students each in both the Treatment and Control Groups (n = 266), who attended a public, high school in rural middle Tennessee. The participants were administered the Force Concepts Inventory (FCI) prior to being taught the mechanics of physics. The FCI data were entered into the computer-based Statistical Package for the Social Science (SPSS). Two independent samples t-tests were conducted to answer the research questions. There was a statistically significant difference between the treatment and control groups concerning the instructional method. Modeling Instructional methods were found to be effective in increasing the academic achievement of students in high school physics. There was no statistically significant difference between FCI gains scores for gender. Gender was found to have no effect on the academic achievement of students in high school physics classes. However, even though there was not a statistically significant difference, female students' gains scores were higher than male students' gains scores when Modeling Instructional methods of teaching were used. Based on these findings, it is recommended

  16. The GRB luminosity function: prediction of the internal shock model and comparison to observations

    SciTech Connect

    Zitouni, H.; Daigne, F.; Mochkovitch, R.

    2008-05-22

    We compute the expected GRB luminosity function in the internal shock model. We find that if the population of GRB central engines produces all kind of relativistic outflows, from very smooth to highly variable, the luminosity function has to branchs: at low luminosity, the distribution is dominated by low efficiency GRBs and is close to a power law of slope -0.5, whereas at high luminosity, the luminosity function follows the distribution of injected kinetic power. Using Monte Carlo simulations and several observational constrains (BATSE logN-logP diagram, peak energy distribution of bright BATSE bursts, fraction of XRFs in the HETE2 sample), we show that it is currently impossible to distinguish between a single power law or a broken power law luminosity function. However, when the second case is considered, the low-luminosity slope is found to be -0.6{+-}0.2, which is compatible with the prediction of the internal shock model.

  17. Nutrition and education. II. Educational achievement and nutrient intake of Chilean elementary and high school graduates.

    PubMed

    Ivanovic, D; Vásquez, M; Marambio, M; Ballester, D; Zacarías, I; Aguayo, M

    1991-12-01

    The interrelationships between educational achievement (EA) and nutrient intake were investigated in 550 Chilean adolescent schoolers graduating from elementary and high school. The random sample included schoolers from both educational levels (1:1), from public and private schools (1:1), and from high, medium, and low socioeconomic status (SES) (1:1:1). Standard procedures for 24-hour dietary recall interviews were used to collect data, and adequacy of intake was assessed by the FAO/WHO Pattern. EA was measured by means of the Achievement Evaluation Program (AEP) and Academic Aptitude Test (AAT) in elementary and high school, respectively. In elementary school graduates, results showed a significant and positive correlation between EA (AEP) and energy, protein, riboflavin, ascorbic acid, calcium and vitamin A intake (Multiple r = 0.456 p less than 0.01; r2 = 0.208). The School Feeding Program beneficiaries who belonged to the low SES presented the lowest EA (AEP) together with a deficient nutrient intake, especially for energy, riboflavin, niacin, vitamin A and calcium, at the same time that they registered the lowest values for those anthropometric parameters, indicators of past nutrition, that is to say height-for-age, weight-for-age, head circumference-for-age and a higher upper-to-lower segment ratio, as compared with non-beneficiaries from the same SES and with those from the higher strata. In high-school graduates, EA (AAT) was found to be significantly and positively correlated with protein, calcium, riboflavin and iron intake (Multiple r = 0.438 p less than 0.001; r2 = 0.192). Nevertheless, these interrelationship are strongly related to SES and sex. Results showed that educational achievement (EA) is significantly and positively associated with nutrient intake, this fact being important for educational planning related to the School Feeding Program. PMID:1841532

  18. Sprite Luminosity and Radio Noise

    NASA Astrophysics Data System (ADS)

    Fullekrug, M.; Evans, A.; Mezentsev, A.; van der Velde, O.; Soula, S.

    2013-12-01

    Sprites are composed of individual streamer discharges (e.g., Pasko, 2010) which split into streamer tips (McHarg et al., 2010) with diameters 50-100 m at 60-80 km height (Kanmae et al., 2012). The sprite luminosity coincides in time and space with extremely low frequency electromagnetic radiation <3 kHz in excellent agreement with theory (Cummer and Fullekrug, 2001). This theory is based on current flowing in the body of sprites at 70-80 km height associated with large streamer densities (Pasko et al., 1998). A more detailed study shows specifically that the exponential growth and splitting of streamers at 70-80 km height results in an electron multiplication associated with the acceleration of electrons to a few eV. The accelerated electrons radiate a small amount of electromagnetic energy and the incoherent superposition of many streamers causes the observed electromagnetic radiation (Qin et al., 2012). It has been predicted that this newly recognized physical mechanism might also result in low frequency ( 30-300 kHz) electromagnetic radiation emanating from sprite streamers near 40 km height in the stratosphere, albeit with very small magnetic fields 10^{-17}-10^{-12} T from a single streamer (Qin et al., 2012). The presence of this predicted radiation was promptly confirmed by low frequency radio noise measurements during dancing sprites with a very sensitive radio receiver (Fullekrug et al., 2013). Specifically, it was found that the sprite luminosity coincides with sudden enhancements of the radio noise. These initial observations are extended here with a more detailed analysis to study the spatial coherence of the radio noise recorded with a novel network of sensitive radio receivers deployed during field work in the summer 2013. This network of radio receivers is used to study the relationship between the radio noise and the sprite luminosity observed with video cameras. The sprite luminosity is inferred from video recordings by use of sophisticated image

  19. Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

    NASA Astrophysics Data System (ADS)

    Belen-Ferrer, Bellasanta

    2009-12-01

    This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

  20. CLIC Crab Cavity Design Optimisation for Maximum Luminosity

    SciTech Connect

    Dexter, A.C.; Burt, G.; Ambattu, P.K.; Dolgashev, V.; Jones, R.; /Manchester U.

    2012-04-25

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  1. Luminosity function and jet structure of Gamma-Ray Burst

    NASA Astrophysics Data System (ADS)

    Pescalli, A.; Ghirlanda, G.; Salafia, O. S.; Ghisellini, G.; Nappo, F.; Salvaterra, R.

    2015-02-01

    The structure of gamma-ray burst (GRB) jets impacts on their prompt and afterglow emission properties. The jet of GRBs could be uniform, with constant energy per unit solid angle within the jet aperture, or it could be structured, namely with energy and velocity that depend on the angular distance from the axis of the jet. We try to get some insight about the still unknown structure of GRBs by studying their luminosity function. We show that low (1046-48 erg s-1) and high (i.e. with L ≥ 1050 erg s-1) luminosity GRBs can be described by a unique luminosity function, which is also consistent with current lower limits in the intermediate luminosity range (1048-50 erg s-1). We derive analytical expressions for the luminosity function of GRBs in uniform and structured jet models and compare them with the data. Uniform jets can reproduce the entire luminosity function with reasonable values of the free parameters. A structured jet can also fit adequately the current data, provided that the energy within the jet is relatively strongly structured, i.e. E ∝ θ-k with k ≥ 4. The classical E ∝ θ-2 structured jet model is excluded by the current data.

  2. Achieving High Performance in AC-Field Driven Organic Light Sources

    PubMed Central

    Xu, Junwei; Carroll, David L.; Smith, Gregory M.; Dun, Chaochao; Cui, Yue

    2016-01-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m2 with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today’s OLEDs in performance. PMID:27063414

  3. Achieving High Performance in AC-Field Driven Organic Light Sources.

    PubMed

    Xu, Junwei; Carroll, David L; Smith, Gregory M; Dun, Chaochao; Cui, Yue

    2016-04-11

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m(2) with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today's OLEDs in performance.

  4. A strategy for achieving high reliability for reusable launch vehicles (RLVs)

    NASA Astrophysics Data System (ADS)

    Sholtis, Joseph A.

    2002-01-01

    Expendable launch vehicles (ELVs) have been used since the early 1960s to put numerous payloads, including humans, into space. Yet, in spite of their widespread use since that time, ELV reliability has not improved much. Why has this been the case? And, more importantly, what might be done to substantially improve the reliability of future reusable launch vehicles (RLVs) to levels needed for commercial viability, i.e., approaching that of the U.S. commercial airline industry? This paper attempts to answer these questions-by reviewing the history of launch vehicles, identifying factors important to their reliability and safety, and in doing so, offering a potential strategy for achieving high RLV reliability. The conclusion reached is that there is every reason to believe that high reliability (~0.99999 per mission) is achievable for future RLVs, if key features to enhance their inherent robustness, forgiveness, and recoverability are considered and integrated into RLV design and operation at the outset. It is hoped that this paper will serve as a catalyst for further discussions intended to ensure that high reliability is realized for RLVs. .

  5. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    NASA Astrophysics Data System (ADS)

    Yang, Ding-Xin; Gu, Feng-Shou; Feng, Guo-Jin; Yang, Yong-Min; Ball, Andrew

    2015-11-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. Project supported by the National Natural Science Foundation of China (Grant No. 51379526).

  6. Race and Academic Achievement in Racially Diverse High Schools: Opportunity and Stratification

    PubMed Central

    MULLER, CHANDRA; RIEGLE-CRUMB, CATHERINE; SCHILLER, KATHRYN S.; WILKINSON, LINDSEY; FRANK, KENNETH A.

    2010-01-01

    Background/Context Brown v Board of Education fundamentally changed our nation's schools, yet we know surprisingly little about how and whether they provide equality of educational opportunity. Although substantial evidence suggests that African American and Latino students who attend these schools face fewer learning opportunities than their White counterparts, until now, it has been impossible to examine this using a representative sample because of lack of data. Purpose/Objective/Research Question/Focus of Study This study uses newly available data to investigate whether racially diverse high schools offer equality of educational opportunity to students from different racial and ethnic groups. This is examined by measuring the relative representation of minority students in advanced math classes at the beginning of high school and estimating whether and how this opportunity structure limits the level of achievement attained by African American and Latino students by the end of high school. Setting This study uses data from the Adolescent Health and Academic Achievement Study (AHAA) and its partner study, the National Longitudinal Study of Adolescent Health (Add Health), a stratified, nationally representative study of students in U.S. high schools first surveyed in 1994–1995. Population/Participants/Subjects Two samples of racially diverse high schools were used in the analysis: one with African Americans, Whites, and Asians (26 schools with 3,149 students), and the other with Latinos, Whites, and Asians (22 schools with 2,775 students). Research Design Quantitative analyses first assess how high schools vary in the extent to which minority students are underrepresented in advanced sophomore math classes. Hierarchical multilevel modeling is then used to estimate whether racial-ethnic differences in representation in advanced math have an impact on African American and Latino students’ achievement by the end of high school, relative to the Whites and Asians

  7. Race and Academic Achievement in Racially Diverse High Schools: Opportunity and Stratification.

    PubMed

    Muller, Chandra; Riegle-Crumb, Catherine; Schiller, Kathryn S; Wilkinson, Lindsey; Frank, Kenneth A

    2010-04-01

    BACKGROUND/CONTEXT: Brown v Board of Education fundamentally changed our nation's schools, yet we know surprisingly little about how and whether they provide equality of educational opportunity. Although substantial evidence suggests that African American and Latino students who attend these schools face fewer learning opportunities than their White counterparts, until now, it has been impossible to examine this using a representative sample because of lack of data. PURPOSE/OBJECTIVE/RESEARCH QUESTION/FOCUS OF STUDY: This study uses newly available data to investigate whether racially diverse high schools offer equality of educational opportunity to students from different racial and ethnic groups. This is examined by measuring the relative representation of minority students in advanced math classes at the beginning of high school and estimating whether and how this opportunity structure limits the level of achievement attained by African American and Latino students by the end of high school. SETTING: This study uses data from the Adolescent Health and Academic Achievement Study (AHAA) and its partner study, the National Longitudinal Study of Adolescent Health (Add Health), a stratified, nationally representative study of students in U.S. high schools first surveyed in 1994-1995. POPULATION/PARTICIPANTS/SUBJECTS: Two samples of racially diverse high schools were used in the analysis: one with African Americans, Whites, and Asians (26 schools with 3,149 students), and the other with Latinos, Whites, and Asians (22 schools with 2,775 students). RESEARCH DESIGN: Quantitative analyses first assess how high schools vary in the extent to which minority students are underrepresented in advanced sophomore math classes. Hierarchical multilevel modeling is then used to estimate whether racial-ethnic differences in representation in advanced math have an impact on African American and Latino students' achievement by the end of high school, relative to the Whites and Asians

  8. Cognitive abilities and motivational processes in high school students' science achievement and engagement

    NASA Astrophysics Data System (ADS)

    Lau, Shun

    The dissertation presents two analytic approaches, a variable-centered and person-centered approach, to investigating holistic patterns of the cognitive, motivational, and affective correlates of science achievement and engagement in a sample of 491 10th and 11th grade high-school students. Building on Snow's (1989) idea of two pathways to achievement outcomes, Study 1 adopted a variable-centered approach to examining how cognitive and motivational factors associated with the performance and commitment pathways, respectively, contributed to the prediction of achievement outcomes in science. Results of hierarchical regression analyses showed that (a) students' cognitive abilities were the strongest predictors of their performance in science as measured by standardized test scores; (b) motivational processes enhanced the predictive validity for science test scores and grades beyond the variance accounted for by ability and demography; (c) motivational processes were the strongest predictors of students' commitment to science in the form of situational engagement and anticipated choices of science-related college majors and careers; and (d) competence beliefs served as a point of contact between the performance and commitment pathways. These results are consistent with Snow's (1989) conjecture that both performance and commitment pathway-related factors are necessary for understanding the full range of person-level inputs to achievement outcomes. Study 2 adopted a person-centered approach to examining holistic organizations of psychological factors within individuals and their relations to science achievement and engagement. Four types of students characterized by unique configurations of cognitive, motivational, and affective attributes were identified in both the male and female subsamples using inverse factor analysis. Type membership was found to distinguish students in various indicators of science achievement and engagement. Two of the four types were also found

  9. High School Principal Instructional Leadership Behavior in High and Low Need and High and Low Achievement Schools

    ERIC Educational Resources Information Center

    Fulton, Theodore T.

    2009-01-01

    The purpose of this study was to investigate teacher perceptions of the ten specific principal instructional leadership behaviors of Hallinger's Principal Instructional Management Rating Scale as they relate to school need, school achievement, years of experience as a teacher, and years working with the current principal. This quantitative…

  10. Number Sense-Based Strategies Used by High-Achieving Sixth Grade Students Who Experienced Reform Textbooks

    ERIC Educational Resources Information Center

    Alsawaie, Othman N.

    2012-01-01

    The purpose of this study was to explore strategies used by high-achieving 6th grade students in the United Arab Emirates (UAE) to solve basic arithmetic problems involving number sense. The sample for the study consisted of 15 high-achieving boys and 15 high-achieving girls in grade 6 from 2 schools in the Emirate of Abu Dhabi, UAE. Data for the…

  11. Achieving high mass-throughput of therapeutic proteins through parvovirus retentive filters.

    PubMed

    Bolton, Glen R; Basha, Jonida; Lacasse, Daniel P

    2010-01-01

    Parvovirus retentive filters that assure removal of viruses and virus-like particles during the production of therapeutic proteins significantly contribute to total manufacturing costs. Operational approaches that can increase throughput and reduce filtration area would result in a significant cost savings. A combination of methods was used to achieve high throughputs of an antibody or therapeutic protein solution through three parvovirus retentive filters. These methods included evaluation of diatomaceous earth or size-based prefilters, the addition of additives, and the optimization of protein concentration, temperature, buffer composition, and solution pH. An optimum temperature of 35°C was found for maximizing throughput through the Virosart CPV and Viresolve Pro filters. Mass-throughput values of 7.3, 26.4, and 76.2 kg/m(2) were achieved through the Asahi Planova 20N, Virosart CPV, and Viresolve Pro filters, respectively, in 4 h of processing. Mass-throughput values of 73, 137, and 192 kg/m(2) were achieved through a Millipore Viresolve Pro filter in 4.0, 8.8, and 22.1 h of processing, respectively, during a single experiment. However, large-scale parvovirus filtration operations are typically controlled to limit volumetric throughput to below the level achieved during small-scale virus spiking experiments. The virus spike may cause significant filter plugging, limiting throughput. Therefore newer parvovirus filter spiking strategies should be adopted that may lead to more representative viral clearance data and higher utilization of large-scale filter capacity.

  12. The Relation of High-Achieving Adolescents' Social Perceptions and Motivation to Teachers' Nominations for Advanced Programs

    ERIC Educational Resources Information Center

    Barber, Carolyn; Torney-Purta, Judith

    2008-01-01

    The discrepancies between test-based and teacher-based criteria of high achievement are well-documented for students of all ages. This study seeks to determine whether certain high school students who score high on tests of academic achievement are more likely than others to be nominated for advanced academic programs by their teachers. Using…

  13. High Intensive Processes and Extreme States of Matter: Achievements and Problems

    SciTech Connect

    Simonenko, V. A.

    2006-08-03

    The paper briefly presents some main highlights of High Energy Density Physics (HEDP) achievements starting from its origin in the 1940s to the current time. A decisive role of high explosives (HE) is emphasized in studying high intensive processes and high energy density states of matter. Mechanisms of detonation and kinetics of energy release still remain acute in the HE studying. Research and scientific applications of nuclear explosions opened a new stage in HEDP development. They provided a million-fold increase of energy density if compared to that of high explosives. High intensive heat waves and strong shock waves were studied and used to measure dense plasma opacities and matter properties under extreme conditions. This data remains important for the development of theoretical models of matter. Powerful pulsed facilities (lasers, electric explosion installations, and charged particle accelerators) were constructed to extend opportunities for the HEDP research. One of their main goals is to study inertial confinement fusion. HEDP technologies and results are very useful in space and astrophysical research, and on the contrary, astrophysical studies enrich HEDP with new models, problems and solutions.

  14. The Pentagon-S process: A systematic approach for achieving high confidence in high-consequence products

    SciTech Connect

    D`Antonio, P.E.; Covan, J.M.; Ekman, M.E.

    1997-10-01

    Sandia National Laboratories has developed a systematic approach for achieving high confidence in major products requiring high reliability for use in high-consequence applications. A high-consequence application is one in which product failure could result in significant loss of life, damage to major systems or to the environment, financial loss, or political repercussions. The application of this process has proven to be of significant benefit in the early identification, verification, and correction of potential product design and manufacturing process failure modes. Early identification and correction of these failures modes and the corresponding controls placed on safety-critical features, ensures product adherence to safety-critical design requirements, and enhances product quality, reliability, and the cost effectiveness of delivered products. Safety-critical features include design features such as materials and dimensions, as well as manufacturing features such as assembly processes, inspections, and testing.

  15. Effectiveness of Problem Solving Method In Dynamics And Academic Achievement of High School Students

    NASA Astrophysics Data System (ADS)

    Ahmadi, F.; Hamidi, F.; Mohammadzadeh, A.; Ahmadi, M. K. A.

    2010-07-01

    The present research as a per and post tests design with control group investigates the effectiveness of problem solving method as independent variable on academic achievement of students in the second grade of high school in the physics topic of dynamics. The sample consists of four random groups as experimental and control groups which were chosen from the students of the second grade of high school. Each sample consists of 25 participants. The experimental groups were taught in problem solving method without any changing in method for control groups. Data was analyzed using Mixed Analysis Of Variance (MANOVA). Result showed a significant difference between two methods of learning (P<0.05). Further the evaluation of their attitude about problem solving method has been showed that a significant percentage of participants in experimental group were interested to continue that method in other physical topics.

  16. Where Are the Academically Successful Puerto Rican Students? Five Success Factors of High Achieving Puerto Rican High School Students. JSRI Working Paper No. 61

    ERIC Educational Resources Information Center

    Antrop-Gonzalez, Rene; Velez, William; Garrett, Tomas

    2003-01-01

    High achieving Puerto Rican high school students are largely missing not only from urban high schools, but also from the educational research. The purpose of this article, then, is to describe the five success factors that ten low-income urban high school students from this ethnic group attributed to their high academic achievement. These success…

  17. High school students' perceptions of EFL teacher control orientations and their English academic achievement.

    PubMed

    Kiany, Gholam Reza; Shayestefar, Parvaneh

    2011-09-01

    BACKGROUND. Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between strong, shared, or loose teacher control during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. AIM. The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). SAMPLE. The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. METHOD. To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok et al. (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. RESULTS AND CONCLUSION. Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students

  18. High school students' perceptions of EFL teacher control orientations and their English academic achievement.

    PubMed

    Kiany, Gholam Reza; Shayestefar, Parvaneh

    2011-09-01

    BACKGROUND. Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between strong, shared, or loose teacher control during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. AIM. The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). SAMPLE. The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. METHOD. To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok et al. (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. RESULTS AND CONCLUSION. Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students

  19. Tuning charge balance in PHOLEDs with ambipolar host materials to achieve high efficiency

    SciTech Connect

    Padmaperuma, Asanga B.; Koech, Phillip K.; Cosimbescu, Lelia; Polikarpov, Evgueni; Swensen, James S.; Chopra, Neetu; So, Franky; Sapochak, Linda S.; Gaspar, Daniel J.

    2009-08-27

    The efficiency and stability of blue organic light emitting devices (OLEDs) continue to be a primary roadblock to developing organic solid state white lighting. For OLEDs to meet the high power conversion efficiency goal, they will require both close to 100% internal quantum efficiency and low operating voltage in a white light emitting device.1 It is generally accepted that such high quantum efficiency, can only be achieved with the use of organometallic phosphor doped OLEDs. Blue OLEDs are particularly important for solid state lighting. The simplest (and therefore likely the lowest cost) method of generating white light is to down convert part of the emission from a blue light source with a system of external phosphors.2 A second method of generating white light requires the superposition of the light from red, green and blue OLEDs in the correct ratio. Either of these two methods (and indeed any method of generating white light with a high color rendering index) critically depends on a high efficiency blue light component.3 A simple OLED generally consists of a hole-injecting anode, a preferentially hole transporting organic layer (HTL), an emissive layer that contains the recombination zone and ideally transports both holes and electrons, a preferentially electron-transporting layer (ETL) and an electron-injecting cathode. Color in state-of-the-art OLEDs is generated by an organometallic phosphor incorporated by co-sublimation into the emissive layer (EML).4 New materials functioning as hosts, emitters, charge transporting, and charge blocking layers have been developed along with device architectures leading to electrophosphorescent based OLEDs with high quantum efficiencies near the theoretical limit. However, the layers added to the device architecture to enable high quantum efficiencies lead to higher operating voltages and correspondingly lower power efficiencies. Achievement of target luminance power efficiencies will require new strategies for lowering

  20. Science literacy in high school students: A comparison of achievement in two curriculum approaches

    NASA Astrophysics Data System (ADS)

    McAlister, Diane C.

    2009-12-01

    Academic achievement as measured by the Florida Comprehensive Assessment Test (FCAT) in science for 367 students in two science curriculum options, integrated science and the traditional subject-specific courses, in one central Florida high school were compared. A multivariate analysis of covariance (MANCOVA) of science curriculum choice was analyzed for three variables, total FCAT score, earth science subscore, and scientific thinking subscore. Covariate of academic ability as defined by grade point average (GPA) and academic focus as defined by post secondary plans were considered for use. Analysis of statistically significant results was completed through analysis of covariance (ANCOVA). While statistically significant results were found in favor of the traditional curriculum group, additional statistical analysis of the curriculum groups for differences in socioeconomic status (SES), gender, and instructional level led to a logistic regression to explore the ability of these variables, GPA, and total FCAT score to predict curriculum group membership. GPA, level of instruction and FCAT score were found to be statistically significant predictors. Final conclusions to the study indicated a significant difference in scientific literacy for the two groups in favor of the traditional curriculum. However, logistic regression results indicated that due to significant differences in SES, gender, GPA, and level of instruction for the groups, the differences in academic achievement were probably due to factors other than curriculum design. Limitations of the study and suggestions for further research were presented.

  1. A Comparison of Strategic Development for Multiplication Problem Solving in Low-, Average-, and High-Achieving Students

    ERIC Educational Resources Information Center

    Zhang, Dake; Ding, Yi; Barrett, Dave E.; Xin, Yan Ping; Liu, Ru-de

    2014-01-01

    The present study investigated the differences of strategy use between low-, average-, and high-achieving students when solving different multiplication problems. Nineteen high-, 48 average-, and 17 low-achieving students participated in this study. All participants were asked to complete three different multiplication tests and to explain how…

  2. Robust and Fragile Mathematical Identities: A Framework for Exploring Racialized Experiences and High Achievement among Black College Students

    ERIC Educational Resources Information Center

    McGee, Ebony O.

    2015-01-01

    I introduce the construct of fragile and robust identities for the purpose of exploring the experiences that influenced the mathematical and racial identities of high-achieving Black college students in mathematics and engineering. These students maintained high levels of academic achievement in these fields while enduring marginalization,…

  3. What Can Teacher Education Programs Do to Prepare Teachers to Teach High-Achieving Culturally Diverse Male Students?

    ERIC Educational Resources Information Center

    Milner, H. Richard; Tenore, F. Blake; Laughter, Judson

    2008-01-01

    In this article, the authors discuss what teacher education programs can do to prepare teachers to teach high-achieving culturally diverse male students. They suggest that special attention needs to be directed at the educational experiences of high-achieving Black male students. They also believe that diverse male learners, and especially high…

  4. Is Early Ability Grouping Good for High-Achieving Students' Psychosocial Development? Effects of the Transition into Academically Selective Schools

    ERIC Educational Resources Information Center

    Becker, Michael; Neumann, Marko; Tetzner, Julia; Böse, Susanne; Knoppick, Henrike; Maaz, Kai; Baumert, Jürgen; Lehmann, Rainer

    2014-01-01

    The present study investigates school context effects on psychosocial characteristics (academic self-concept, peer relations, school satisfaction, and school anxiety) of high-achieving and gifted students. Students who did or did not make an early transition from elementary to secondary schools for high-achieving and gifted students in 5th grade…

  5. Speculations on a relativistic strong focusing self-collider with very high luminosity (≥10 40 cm -2s -1): Macroproduction of antinuclei and other micro cross section events and formation of ambiplasma

    NASA Astrophysics Data System (ADS)

    Maglich, Bogdan C.

    1988-08-01

    The luminosity of the weak focusing self-collider (ESCOL) is intrinsically 10 8-10 10 times greater than that of conventional colliding beams, due to the product of the solid angle factor, ˜10 6, and the neutralization factor, ˜10 2 -10 4. We extrapolate to 10-GeV protons the parameters of a recent low energy experiment demonstrating that a 1-MeV deuteron beam, stored in ESCOL as migma, can be neutralized bo oscillating electrons and operate an order of magnitude above the space charge limit without instabilities. With the number density achieved in ESCOL, n = 3.2 × 10 9 ions cm -3, such a relativistic strong focusing self-collider (XYDER) would have a luminosity L ˜ 10 38 cm -2 s -1 for 10-GeV-on-10-GeV protons (equivalent to 250 GeV beam-on-target). At the diamagnetic "limit" density, which for 10 tesla is n = 10 12 ions cm -3, l ˜ 10 43 cm -2 s -1; this would produce 4 × 10 16 antiprotons/s (2 gram of overlinep/year). Other particles, rare nuclei, and rare effects produced with micro- (10 -16), nano- (10 -9 b), and picoscopic (10 -12 b) cross sections will be macro-produced in XYDER. A newly proposed annular magnet would provide a large volume of stored, V = 10 9 cm 3, as well as automatic ejection along the +z and -z axes of the overlinep's and other particles whose momentum is lower than that of the primary proton migma. Antiprotons, being produced with low rapidity, will have energies below 1 GeV in COM, and thus are suitable for beaming, extraction, cooling, abd slowing down to be either stored for space propulsion or used as a source for acceleration. If the magnetic field strength is adjusted for the antiprotons to be confined, an unusual plasma will be formed, consisting of the protons, antiprotons, electrons, and positrons (from pion-muon-electron decays), and similar to Alfvèns "ambiplasman". Its plasmic beta will be unity already at low densities (˜10 11 cm -3 where ωpi/ ωci ≤ 1); the ion-to-electron "temperature" ratio will never achieve

  6. Conflicts and communication between high-achieving Chinese American adolescents and their parents.

    PubMed

    Qin, Desiree Baolian; Chang, Tzu-Fen; Han, Eun-Jin; Chee, Grace

    2012-01-01

    Drawing on in-depth interview data collected on 18 high-achieving Chinese American students, the authors examine domains of acculturation-based conflicts, parent and child internal conflicts, and conflict resolution in their families. Their analyses show that well-established negative communication patterns in educational expectations, divergent attitudes toward other races and country of origin, and cultural and language barriers contributed to parent-child conflicts. Their findings also illustrate important internal conflicts both adolescents and parents had along the cultural tightrope of autonomy and relatedness. Finally, the vertical in-group conflict resolution style that was evidenced in youths' accounts raises questions about cultural differences in constructive versus destructive conflict resolution styles.

  7. Achieving behavioral control with millisecond resolution in a high-level programming environment.

    PubMed

    Asaad, Wael F; Eskandar, Emad N

    2008-08-30

    The creation of psychophysical tasks for the behavioral neurosciences has generally relied upon low-level software running on a limited range of hardware. Despite the availability of software that allows the coding of behavioral tasks in high-level programming environments, many researchers are still reluctant to trust the temporal accuracy and resolution of programs running in such environments, especially when they run atop non-real-time operating systems. Thus, the creation of behavioral paradigms has been slowed by the intricacy of the coding required and their dissemination across labs has been hampered by the various types of hardware needed. However, we demonstrate here that, when proper measures are taken to handle the various sources of temporal error, accuracy can be achieved at the 1 ms time-scale that is relevant for the alignment of behavioral and neural events.

  8. Strategies for achieving high-level expression of genes in Escherichia coli.

    PubMed Central

    Makrides, S C

    1996-01-01

    Progress in our understanding of several biological processes promises to broaden the usefulness of Escherichia coli as a tool for gene expression. There is an expanding choice of tightly regulated prokaryotic promoters suitable for achieving high-level gene expression. New host strains facilitate the formation of disulfide bonds in the reducing environment of the cytoplasm and offer higher protein yields by minimizing proteolytic degradation. Insights into the process of protein translocation across the bacterial membranes may eventually make it possible to achieve robust secretion of specific proteins into the culture medium. Studies involving molecular chaperones have shown that in specific cases, chaperones can be very effective for improved protein folding, solubility, and membrane transport. Negative results derived from such studies are also instructive in formulating different strategies. The remarkable increase in the availability of fusion partners offers a wide range of tools for improved protein folding, solubility, protection from proteases, yield, and secretion into the culture medium, as well as for detection and purification of recombinant proteins. Codon usage is known to present a potential impediment to high-level gene expression in E. coli. Although we still do not understand all the rules governing this phenomenon, it is apparent that "rare" codons, depending on their frequency and context, can have an adverse effect on protein levels. Usually, this problem can be alleviated by modification of the relevant codons or by coexpression of the cognate tRNA genes. Finally, the elucidation of specific determinants of protein degradation, a plethora of protease-deficient host strains, and methods to stabilize proteins afford new strategies to minimize proteolytic susceptibility of recombinant proteins in E. coli. PMID:8840785

  9. Measuring the Radius of a Neutron Star; Origin of High X-Ray Luminosities in Optically Passive Galaxies; Resolving the Source of X-Rays in IC 1613"

    NASA Technical Reports Server (NTRS)

    Helfand, David J.

    1998-01-01

    This recently expired grant has supported the work of the PI, his students, and his collaborators on a variety of ROSAT projects over the past three years. Annual reports have summarized much of the work accomplished; here we provide a brief review of the work resulting from this effort, and a summary of the personnel who have benefited from its support. A high resolution ROSAT HRI X-ray image of the Local Group dwarf IC1613 revealed that the principal source of X-ray emission in this direction arises in a background cluster of galaxies, as first suggested by Eskridge (1995). In addition, however, we found a bright X-ray source coincident with the only known supernova remnant in this galaxy, S # 8. Extensive ground-based follow-up observations in the radio and optical regimes were conducted. We confirmed the nonthermal radio spectral index of the source and measured its extent to be approx. 3 sec at 20 cm. Imaging spectrophotometric observations taken with the multi-pupil spectrograph of the Special Astrophysical Observatory in the FSU allowed us to determine the density and velocity distribution of the gas in the remnant. The simultaneous presence of luminous X-ray and optical emission suggests a relatively young remnant in which the outward-moving shock has recently encountered dense material. Many of this object's properties are similar to those of the brightest optical remnant in the Large Magellanic Cloud, N49. Another potential source of X-rays in this galaxy which featured prominently in our original proposal, an Oxygen Wolf-Rayet star with a large surrounding wind-blown bubble, was not detected.

  10. Achieving Highly Efficient, Selective, and Stable CO2 Reduction on Nitrogen-Doped Carbon Nanotubes.

    PubMed

    Wu, Jingjie; Yadav, Ram Manohar; Liu, Mingjie; Sharma, Pranav P; Tiwary, Chandra Sekhar; Ma, Lulu; Zou, Xiaolong; Zhou, Xiao-Dong; Yakobson, Boris I; Lou, Jun; Ajayan, Pulickel M

    2015-05-26

    The challenge in the electrosynthesis of fuels from CO2 is to achieve durable and active performance with cost-effective catalysts. Here, we report that carbon nanotubes (CNTs), doped with nitrogen to form resident electron-rich defects, can act as highly efficient and, more importantly, stable catalysts for the conversion of CO2 to CO. The unprecedented overpotential (-0.18 V) and selectivity (80%) observed on nitrogen-doped CNTs (NCNTs) are attributed to their unique features to facilitate the reaction, including (i) high electrical conductivity, (ii) preferable catalytic sites (pyridinic N defects), and (iii) low free energy for CO2 activation and high barrier for hydrogen evolution. Indeed, DFT calculations show a low free energy barrier for the potential-limiting step to form key intermediate COOH as well as strong binding energy of adsorbed COOH and weak binding energy for the adsorbed CO. The highest selective site toward CO production is pyridinic N, and the NCNT-based electrodes exhibit no degradation over 10 h of continuous operation, suggesting the structural stability of the electrode.

  11. On the Radio and Optical Luminosity Evolution of Quasars

    SciTech Connect

    Singal, J.; Petrosian, V.; Lawrence, A.; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.

    2011-05-20

    We calculate simultaneously the radio and optical luminosity evolutions of quasars, and the distribution in radio loudness R defined as the ratio of radio and optical luminosities, using a flux limited data set containing 636 quasars with radio and optical fluxes from White et al. We first note that when dealing with multivariate data it is imperative to first determine the true correlations among the variables, not those introduced by the observational selection effects, before obtaining the individual distributions of the variables. We use the methods developed by Efron and Petrosian which are designed to obtain unbiased correlations, distributions, and evolution with redshift from a data set truncated due to observational biases. It is found that as expected the population of quasars exhibits strong positive correlation between the radio and optical luminosities and that this correlation deviates from a simple linear relation in a way indicating that more luminous quasars are more radio loud. We also find that there is a strong luminosity evolution with redshift in both wavebands, with significantly higher radio than optical evolution. We conclude that the luminosity evolution obtained by arbitrarily separating the sources into radio loud (R > 10) and radio quiet (R < 10) populations introduces significant biases that skew the result considerably. We also construct the local radio and optical luminosity functions and the density evolution. Finally, we consider the distribution of the radio loudness parameter R obtained from careful treatment of the selection effects and luminosity evolutions with that obtained from the raw data without such considerations. We find a significant difference between the two distributions and no clear sign of bi-modality in the true distribution. Our results indicate therefore, somewhat surprisingly, that there is no critical switch in the efficiency of the production of disk outflows/jets between very radio quiet and very radio

  12. Superintendent Leadership and Student Achievement in Suburban High Schools: A Sequential Explanatory Mixed Methods Analysis

    ERIC Educational Resources Information Center

    Kellner, Steven Reese

    2012-01-01

    This research study explored the critical nature of the connection between student achievement and superintendent leadership. A great deal of scholarship has addressed either student achievement or leadership and previous evidence has suggested the impact of both parental education and racioethnicity on student achievement, but few studies have…

  13. The Effects of School Bonding on High School Seniors' Academic Achievement

    ERIC Educational Resources Information Center

    Bryan, Julia; Moore-Thomas, Cheryl; Gaenzle, Stacey; Kim, Jungnam; Lin, Chia-Huei; Na, Goeun

    2012-01-01

    The authors examine the effects of school bonding on academic achievement (measured by math achievement scores) in a sample of 12th graders from the Educational Longitudinal Study of 2002 (Ingels, Pratt, Rogers, Siegel, & Stutts, 2005). Components of school bonding have proximal and distal effects on academic achievement. Attachment to school and…

  14. Why Try? Factors that Differentiate Underachieving Gifted Students from High Achieving Gifted Students.

    ERIC Educational Resources Information Center

    McCoach, D. Betsy; Siegle, Del

    This report discusses the outcomes of a study that investigated the relationship between student scores on the five sub-scales of the School Attitude Assessment Survey-Revised (SAAS-R) and the academic achievement of known groups of gifted achievers and gifted underachievers. The study examined whether gifted achievers and gifted underachievers…

  15. Achieving a high-reliability organization through implementation of the ARCC model for systemwide sustainability of evidence-based practice.

    PubMed

    Melnyk, Bernadette Mazurek

    2012-01-01

    High-reliability health care organizations are those that provide care that is safe and one that minimizes errors while achieving exceptional performance in quality and safety. This article presents major concepts and characteristics of a patient safety culture and a high-reliability health care organization and explains how building a culture of evidence-based practice can assist organizations in achieving high reliability. The ARCC (Advancing Research and Clinical practice through close Collaboration) model for systemwide implementation and sustainability of evidence-based practice is highlighted as a key strategy in achieving high reliability in health care organizations.

  16. Achieving High-Energy-High-Power Density in a Flexible Quasi-Solid-State Sodium Ion Capacitor.

    PubMed

    Li, Hongsen; Peng, Lele; Zhu, Yue; Zhang, Xiaogang; Yu, Guihua

    2016-09-14

    Simultaneous integration of high-energy output with high-power delivery is a major challenge for electrochemical energy storage systems, limiting dual fine attributes on a device. We introduce a quasi-solid-state sodium ion capacitor (NIC) based on a battery type urchin-like Na2Ti3O7 anode and a capacitor type peanut shell derived carbon cathode, using a sodium ion conducting gel polymer as electrolyte, achieving high-energy-high-power characteristics in solid state. Energy densities can reach 111.2 Wh kg(-1) at power density of 800 W kg(-1), and 33.2 Wh kg(-1) at power density of 11200 W kg(-1), which are among the best reported state-of-the-art NICs. The designed device also exhibits long-term cycling stability over 3000 cycles with capacity retention ∼86%. Furthermore, we demonstrate the assembly of a highly flexible quasi-solid-state NIC and it shows no obvious capacity loss under different bending conditions. PMID:27500429

  17. Achieving High-Energy-High-Power Density in a Flexible Quasi-Solid-State Sodium Ion Capacitor.

    PubMed

    Li, Hongsen; Peng, Lele; Zhu, Yue; Zhang, Xiaogang; Yu, Guihua

    2016-09-14

    Simultaneous integration of high-energy output with high-power delivery is a major challenge for electrochemical energy storage systems, limiting dual fine attributes on a device. We introduce a quasi-solid-state sodium ion capacitor (NIC) based on a battery type urchin-like Na2Ti3O7 anode and a capacitor type peanut shell derived carbon cathode, using a sodium ion conducting gel polymer as electrolyte, achieving high-energy-high-power characteristics in solid state. Energy densities can reach 111.2 Wh kg(-1) at power density of 800 W kg(-1), and 33.2 Wh kg(-1) at power density of 11200 W kg(-1), which are among the best reported state-of-the-art NICs. The designed device also exhibits long-term cycling stability over 3000 cycles with capacity retention ∼86%. Furthermore, we demonstrate the assembly of a highly flexible quasi-solid-state NIC and it shows no obvious capacity loss under different bending conditions.

  18. Achievement of high nuclear spin polarization using lanthanides as low-temperature NMR relaxation agents.

    PubMed

    Peat, David T; Horsewill, Anthony J; Köckenberger, Walter; Perez Linde, Angel J; Gadian, David G; Owers-Bradley, John R

    2013-05-28

    Many approaches are now available for achieving high levels of nuclear spin polarization. One of these methods is based on the notion that as the temperature is reduced, the equilibrium nuclear polarization will increase, according to the Boltzmann distribution. The main problem with this approach is the length of time it may take to approach thermal equilibrium at low temperatures, since nuclear relaxation times (characterized by the spin-lattice relaxation time T1) can become very long. Here, we show, by means of relaxation time measurements of frozen solutions, that selected lanthanide ions, in the form of their chelates with DTPA, can act as effective relaxation agents at low temperatures. Differential effects are seen with the different lanthanides that were tested, holmium and dysprosium showing highest relaxivity, while gadolinium is ineffective at temperatures of 20 K and below. These observations are consistent with the known electron-spin relaxation time characteristics of these lanthanides. The maximum relaxivity occurs at around 10 K for Ho-DTPA and 20 K for Dy-DTPA. Moreover, these two agents show only modest relaxivity at room temperature, and can thus be regarded as relaxation switches. We conclude that these agents can speed up solid state NMR experiments by reducing the T1 values of the relevant nuclei, and hence increasing the rate at which data can be acquired. They could also be of value in the context of a simple low-cost method of achieving several-hundred-fold improvements in polarization for experiments in which samples are pre-polarized at low temperatures, then rewarmed and dissolved immediately prior to analysis.

  19. Implications of the Observed Ultraluminous X-Ray Source Luminosity Function

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.; Tennant, Allyn; Soria, Roberto; Yukita, Mihoko

    2012-01-01

    We present the X-ray luminosity function (XLF) of ultraluminous X-ray (ULX) sources with 0.3-10.0 keV luminosities in excess of 10(sup 39) erg/s in a complete sample of nearby galaxies. The XLF shows a break or cut-off at high luminosities that deviates from its pure power law distribution at lower luminosities. The cut-off is at roughly the Eddington luminosity for a 90-140 solar mass accretor. We examine the effects on the observed XLF of sample biases, of small-number statistics (at the high luminosity end) and of measurement uncertainties. We consider the physical implications of the shape and normalization of the XLF. The XLF is also compared and contrasted to results of other recent surveys.

  20. Autonomous Information Fading and Provision to Achieve High Response Time in Distributed Information Systems

    NASA Astrophysics Data System (ADS)

    Lu, Xiaodong; Arfaoui, Helene; Mori, Kinji

    In highly dynamic electronic commerce environment, the need for adaptability and rapid response time to information service systems has become increasingly important. In order to cope with the continuously changing conditions of service provision and utilization, Faded Information Field (FIF) has been proposed. FIF is a distributed information service system architecture, sustained by push/pull mobile agents to bring high-assurance of services through a recursive demand-oriented provision of the most popular information closer to the users to make a tradeoff between the cost of information service allocation and access. In this paper, based on the analysis of the relationship that exists among the users distribution, information provision and access time, we propose the technology for FIF design to resolve the competing requirements of users and providers to improve users' access time. In addition, to achieve dynamic load balancing with changing users preference, the autonomous information reallocation technology is proposed. We proved the effectiveness of the proposed technology through the simulation and comparison with the conventional system.

  1. The influence of momentary classroom goal structures on student engagement and achievement in high school science

    NASA Astrophysics Data System (ADS)

    Zaleski, Diana Janet

    Teachers' instructional practices fundamentally shape students' classroom experiences. However, it is still unclear what patterns of instructional practice are related to specific classroom goal structures, and how momentary changes in classroom goal structures affect students' momentary cognitive engagement in high school science. This study examined the relationship between classroom goal structures in high school science and two different learning outcomes: (1) students' cognitive engagement in science and (2) students' science course grades. To achieve this aim, classroom goal structures were examined as both a variable feature of the classroom that shifts from activity to activity (i.e., momentary classroom goal structure), and as a single global characteristic describing the dominant goal structure of a classroom over time (i.e., global classroom goal structure). Students' momentary cognitive engagement significantly increased when instructional moments were mastery or performance goal structured compared to moments that had no identifiable goal structure. However, no relationships were found between global classroom goal structure and cognitive engagement or science course grades.

  2. Design strategies for achieving high triplet energy electron transporting host materials for blue electrophosphorescence

    SciTech Connect

    Sapochak, Linda S.; Padmaperuma, Asanga B.; Vecchi, Paul A.; Qiao, Hong; Burrows, Paul E.

    2006-12-01

    High efficiency small molecule organic light emitting devices (OLEDs) based on light emission from an electrophosphorescent dopant dispersed in an organic host matrix are well known. Achieving blue phosphorescent OLEDs is particularly challenging because the host triplet energy should ideally be > 2.8 eV to prevent back-transfer of energy from the dopant to the host matrix resulting in loss of efficiency. A design strategy for developing new host materials with high triplet energies by using phosphine oxide (P=O) moieties as points of saturation in order to build sublimable, electron transporting host materials starting from small, wide bandgap molecular building blocks (i.e., biphenyl, phenyl, naphthalene, octafluorobiphenyl, and N-ethylcarbazole) is described. Electrophosphorescent OLEDs using the organic phosphine oxide compounds as host materials for the sky blue organometallic phosphor, iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2’) picolinate (FIrpic) give maximum external quantum efficiencies of ~ 8% and maximum luminance power efficiencies up to 25 lm/W.

  3. Achieving Energy Savings with Highly-Controlled Lighting in an Open-Plan Office

    SciTech Connect

    Rubinstein, Francis; Enscoe, Abby

    2010-04-19

    An installation in a Federal building tested the effectiveness of a highly-controlled, workstation-specific lighting retrofit. The study took place in an open-office area with 86 cubicles and low levels of daylight. Each cubicle was illuminated by a direct/indirectpendant luminaire with three 32 watt lamps, two dimmable DALI ballasts, and an occupancy sensor. A centralized control system programmed all three lamps to turn on and off according to occupancy on a workstation-by-workstation basis. Field measurements taken over the course of several monthsdemonstrated 40% lighting energy savings compared to a baseline without advanced controls that conforms to GSA's current retrofit standard. A photometric analysis found that the installation provided higher desktop light levels than the baseline, while an occupant survey found that occupants in general preferred the lighting system to thebaseline.Simple payback is fairly high; projects that can achieve lower installation costs and/or higher energy savings and those in which greenhouse gas reduction and occupant satisfaction are significant priorities provide the ideal setting for workstation-specific lighting retrofits.

  4. Tracking with wire chambers at high luminosities

    SciTech Connect

    Hanson, G.G. Stanford Linear Accelerator Center, Menlo Park, CA )

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs.

  5. Do Low Luminosity Stars Matter?

    NASA Astrophysics Data System (ADS)

    Ruiz, María Teresa

    2010-11-01

    Historically, low luminosity stars have attracted very little attention, in part because they are difficult to see except with large telescopes, however, by neglecting to study them we are leaving out the vast majority of stars in the Universe. Low mass stars evolve very slowly, it takes them trillions of years to burn their hydrogen, after which, they just turn into a He white dwarf, without ever going through the red giant phase. This lack of observable evolution partly explains the lack of interest in them. The search for the “missing mass” in the galactic plane turned things around and during the 60s and 70s the search for large M/L objects placed M-dwarfs and cool WDs among objects of astrophysical interest. New fields of astronomical research, like BDs and exoplanets appeared as spin-offs from efforts to find the “missing mass”. The search for halo white dwarfs, believed to be responsible for the observed microlensing events, is pursued by several groups. The progress in these last few years has been tremendous, here I present highlights some of the great successes in the field and point to some of the still unsolved issues.

  6. Longitudinal Outcomes of Start Time Delay on Sleep, Behavior, and Achievement in High School

    PubMed Central

    Thacher, Pamela V.; Onyper, Serge V.

    2016-01-01

    Study Objectives: To establish whether sleep, health, mood, behavior, and academics improved after a 45-minute delay in high school start time, and whether changes persisted longitudinally. Methods: We collected data from school records and student self-report across a number of domains at baseline (May 2012) and at two follow-up time points (November 2012 and May 2013), at a public high school in upstate New York. Students enrolled during academic years (AY) 2011–2012 and 2012–2013 completed the Pittsburgh Sleep Quality Index; the DASS-21; the “Owl-Lark” Scale; the Daytime Sleepiness Index; and a brief self-report of health. Reports from school records regarding attendance, tardiness, disciplinary violations, and academic performance were collected for AY 2010–2011 through 2013–2014. Results: Students delayed but did not extend their sleep period; we found lasting improvements in tardiness and disciplinary violations after the start-time delay, but no changes to other variables. At the first follow-up, students reported 20 minutes longer sleep, driven by later rise times and stable bed times. At the second follow-up, students maintained later rise times but delayed bedtimes, returning total sleep to baseline levels. A delay in rise time, paralleling the delay in the start time that occurred, resulted in less tardiness and decreased disciplinary incidents, but larger improvements to sleep patterns may be necessary to affect health, attendance, sleepiness, and academic performance. Conclusions: Later start times improved tardiness and disciplinary issues at this school district. A delay in start time may be a necessary but not sufficient means to increase sleep time and may depend on preexisting individual differences. Commentary: A commentary on this article appears in this issue on page 267. Citation: Thacher PV, Onyper SV. Longitudinal outcomes of start time delay on sleep, behavior, and achievement in high school. SLEEP 2016;39(2):271–281. PMID

  7. A Study Comparing the Academic Achievement of African American Male Students Enrolled in Two Types of Nontraditional High Schools

    ERIC Educational Resources Information Center

    Rutledge, Anthony B.

    2010-01-01

    This study examined the relationship of the achievement of African American male students enrolled in an early college high school to those enrolled in a performing arts high school. The Georgia High School Graduation Test (GHSGT) scores of the 11th-grade African American male students from an early college high school were compared to the GHSGT…

  8. A study of the temperatures achievable by expansion of high pressure gas

    NASA Astrophysics Data System (ADS)

    Mohan, S. R.; Stollery, J. L.

    1980-08-01

    An experimental investigation of the achievement of cryogenic temperatures by the adiabatic isentropic expansion of a gas is presented. The test apparatus is a light piston tunnel, and the working gas nitrogen. It was determined that cryogenic temperatures were achieved by a polytropic process with an exponent of between 1.3 and 1.4. To achieve a temperature of 120 K from an initial temperature of 300 K, a pressure ratio of 35 will typically be required.

  9. Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

    PubMed

    Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

    2016-02-01

    A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively.

  10. Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

    PubMed

    Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

    2016-02-01

    A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively. PMID:26820247

  11. The Relationship between Professional Learning Community Implementation and Academic Achievement and Graduation Rates in Georgia High Schools

    ERIC Educational Resources Information Center

    Hardinger, Regina Gail

    2013-01-01

    Many educational administrators in Georgia continue to struggle with low student academic achievement and low high school graduation rates. DuFour's professional learning community (PLC) theory suggests a positive relationship between levels of PLC implementation and academic achievement and between levels of PLC implementation and graduation…

  12. The Relationship between Professional Learning Communities, Personal Teacher Efficacy, and Student Achievement at the High School Level

    ERIC Educational Resources Information Center

    Brooks, Sherri L.

    2013-01-01

    The purpose of this correlational study was to determine if there was a relationship between professional learning community (PLC), personal teacher efficacy (PTE), and student achievement. The study examined teacher perception of PLC implementation and PET as it related to student achievement at the high school level on the Virginia End-of Course…

  13. Performance Assessment of High and Low Income Families through "Online RAW Achievement Battery Test" of Primary Grade Students

    ERIC Educational Resources Information Center

    Ahmed, Tamim; Hanif, Maria

    2016-01-01

    This study is intended to investigate student's achievement capability among two families i.e. Low and High income families and designed for primary level learners. A Reading, Arithmetic and Writing (RAW) Achievement test that was developed as a part of another research study (Tamim Ahmed Khan, 2015) was adopted for this study. Both English medium…

  14. Extrinsic Motivation for Large-Scale Assessments: A Case Study of a Student Achievement Program at One Urban High School

    ERIC Educational Resources Information Center

    Emmett, Joshua; McGee, Dean

    2013-01-01

    The purpose of this case study was to discover the critical attributes of a student achievement program, known as "Think Gold," implemented at one urban comprehensive high school as part of the improvement process. Student achievement on state assessments improved during the period under study. The study draws upon perspectives on motivation as a…

  15. (Re)Defining the Narrative: High-Achieving Nontraditional Black Male Undergraduates at a Historically Black College and University

    ERIC Educational Resources Information Center

    Goings, Ramon B.

    2016-01-01

    Using Harper's anti-deficit achievement framework as a theoretical guide, the purpose of this phenomenological study was to investigate the academic and social experiences of four nontraditional, high-achieving, Black male undergraduates attending one historically Black university. Findings show that the participants were intrinsically motivated…

  16. A Multi-Institutional Study of the Relationship between High School Mathematics Achievement and Performance in Introductory College Statistics

    ERIC Educational Resources Information Center

    Dupuis, Danielle N.; Medhanie, Amanuel; Harwell, Michael; LeBeau, Brandon; Monson, Debra; Post, Thomas R.

    2012-01-01

    In this study we examined the effects of prior mathematics achievement and completion of a commercially developed, National Science Foundation-funded, or University of Chicago School Mathematics Project high school mathematics curriculum on achievement in students' first college statistics course. Specifically, we examined the relationship between…

  17. American High School Students from Different Ethnic Backgrounds: The Role of Parents and the Classroom in Achievement Motivation

    ERIC Educational Resources Information Center

    Kim, Jung-In

    2015-01-01

    The purpose of this study was to investigate the relationships between ethnically diverse US high school students' (N = 331) perceptions of their parents' or classroom's motivating factors and their achievement motivation in their math class, connecting achievement goal orientation and self-determination theories. Two hypothesized path models were…

  18. Academic Achievement Trajectories of Homeless and Highly Mobile Students: Resilience in the Context of Chronic and Acute Risk

    ERIC Educational Resources Information Center

    Cutuli, J. J.; Desjardins, Christopher David; Herbers, Janette E.; Long, Jeffrey D.; Heistad, David; Chan, Chi-Keung; Hinz, Elizabeth; Masten, Ann S.

    2013-01-01

    Analyses examined academic achievement data across third through eighth grades ("N" = 26,474), comparing students identified as homeless or highly mobile (HHM) with other students in the federal free meal program (FM), reduced price meals (RM), or neither (General). Achievement was lower as a function of rising risk status (General greater than RM…

  19. The Impact of Principal Perception on Student Academic Climate and Achievement in High School: How Does It Measure Up?

    ERIC Educational Resources Information Center

    Urick, Angela; Bowers, Alex J.

    2014-01-01

    The purpose of this study is to examine the independent direct effects of student and principal perceptions of academic climate on student achievement in high school. To date, few studies have considered the influence of principal perceptions of academic climate on student achievement. In the present study, we test a set of two-level hierarchical…

  20. An Emerging Professional Identity: Influences on the Achievement of High-Ability First-Generation College Females

    ERIC Educational Resources Information Center

    Speirs Neumeister, Kristie L.; Rinker, Julie

    2006-01-01

    Using a qualitative interview design, this study examined factors contributing to the academic achievement of gifted first-generation college females. Findings indicated an emerging professional identity as the primary influence on achievement. The participants' high ability served as a passport to accessing coursework, extracurricular…