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Sample records for 2mass extended source

  1. 2MASS Extended Source Catalog: Overview and Algorithms

    NASA Technical Reports Server (NTRS)

    Jarrett, T.; Chester, T.; Cutri, R.; Schneider, S.; Skrutskie, M.; Huchra, J.

    1999-01-01

    The 2 Micron All-Sky Survey (2MASS)will observe over one-million galaxies and extended Galactic sources covering the entire sky at wavelenghts between 1 and 2 m. Most of these galaxies, from 70 to 80%, will be newly catalogued objetcs.

  2. Extended variational approach to the SU(2) mass gap on the lattice

    SciTech Connect

    Akeyo, J.O. ); Jones, H.F.; Parker, C.S. )

    1995-02-01

    The linear [delta] expansion is applied to a calculation of the SU(2) mass gap on the lattice. Our results compare favorably with the strong-coupling expansion and are in good agreement with recent Monte Carlo estimates.

  3. XID II: STATISTICAL CROSS-ASSOCIATION OF ROSAT BRIGHT SOURCE CATALOG X-RAY SOURCES WITH 2MASS POINT SOURCE CATALOG NEAR-INFRARED SOURCES

    SciTech Connect

    Haakonsen, Christian Bernt; Rutledge, Robert E. E-mail: rutledge@physics.mcgill.ca

    2009-09-01

    The 18,806 ROSAT All Sky Survey Bright Source Catalog (RASS/BSC) X-ray sources are quantitatively cross-associated with near-infrared (NIR) sources from the Two Micron All Sky Survey Point Source Catalog (2MASS/PSC). An association catalog is presented, listing the most likely counterpart for each RASS/BSC source, the probability P {sub id} that the NIR source and X-ray source are uniquely associated, and the probability P {sub no-id} that none of the 2MASS/PSC sources are associated with the X-ray source. The catalog includes 3853 high quality (P {sub id}>0.98) X-ray-NIR matches, 2280 medium quality (0.98 {>=} P {sub id}>0.9) matches, and 4153 low quality (0.9 {>=} P {sub id}>0.5) matches. Of the high quality matches, 1418 are associations that are not listed in the SIMBAD database, and for which no high quality match with a USNO-A2 optical source was presented for the RASS/BSC source in previous work. The present work offers a significant number of new associations with RASS/BSC objects that will require optical/NIR spectroscopy for classification. For example, of the 6133 P {sub id}>0.9 2MASS/PSC counterparts presented in the association catalog, 2411 have no classification listed in the SIMBAD database. These 2MASS/PSC sources will likely include scientifically useful examples of known source classes of X-ray emitters (white dwarfs, coronally active stars, active galactic nuclei), but may also contain previously unknown source classes. It is determined that all coronally active stars in the RASS/BSC should have a counterpart in the 2MASS/PSC, and that the unique association of these RASS/BSC sources with their NIR counterparts thus is confusion limited.

  4. Extended source model for diffusive coupling.

    PubMed

    González-Ochoa, Héctor O; Flores-Moreno, Roberto; Reyes, Luz M; Femat, Ricardo

    2016-01-01

    Motivated by the prevailing approach to diffusion coupling phenomena which considers point-like diffusing sources, we derived an analogous expression for the concentration rate of change of diffusively coupled extended containers. The proposed equation, together with expressions based on solutions to the diffusion equation, is intended to be applied to the numerical solution of systems exclusively composed of ordinary differential equations, however is able to account for effects due the finite size of the coupled sources.

  5. Extended source model for diffusive coupling.

    PubMed

    González-Ochoa, Héctor O; Flores-Moreno, Roberto; Reyes, Luz M; Femat, Ricardo

    2016-01-01

    Motivated by the prevailing approach to diffusion coupling phenomena which considers point-like diffusing sources, we derived an analogous expression for the concentration rate of change of diffusively coupled extended containers. The proposed equation, together with expressions based on solutions to the diffusion equation, is intended to be applied to the numerical solution of systems exclusively composed of ordinary differential equations, however is able to account for effects due the finite size of the coupled sources. PMID:26802012

  6. Spectral Mapping Reconstruction of Extended Sources

    NASA Astrophysics Data System (ADS)

    Smith, J. D. T.; Armus, L.; Dale, D. A.; Roussel, H.; Sheth, K.; Buckalew, B. A.; Jarrett, T. H.; Helou, G.; Kennicutt, R. C., Jr.

    2007-10-01

    Three-dimensional spectroscopy of extended sources is typically performed with dedicated integral field spectrographs. We describe a method of reconstructing full spectral cubes, with two spatial and one spectral dimension, from rastered spectral mapping observations employing a single slit in a traditional slit spectrograph. When the background and image characteristics are stable, as is often achieved in space, the use of traditional long slits for integral field spectroscopy can substantially reduce instrument complexity over dedicated integral field designs, without loss of mapping efficiency-particularly compelling when a long-slit mode for single unresolved source follow-up is separately required. We detail a custom flux-conserving cube reconstruction algorithm, discuss issues of extended-source flux calibration, and describe CUBISM, a tool that implements these methods for spectral maps obtained with the Spitzer Space Telescope's Infrared Spectrograph.

  7. Extended Source/Galaxy All Sky 2

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This panoramic view encompasses the entire sky and reveals the distribution of galaxies beyond the Milky Way galaxy, which astronomers call extended sources, as observed by Two Micron All-Sky Survey. The image is assembled from a database of over 1.6 million galaxies listed in the survey's All-Sky Survey Extended Source Catalog,; more than half of the galaxies have never before been catalogued. The colors represent how the many galaxies appear at three distinct wavelengths of infrared light (blue at 1.2 microns, green at 1.6 microns, and red at 2.2 microns). Quite evident are the many galactic clusters and superclusters, as well as some streamers composing the large-scale structure of the nearby universe. The blue overlay represents the very close and bright stars from our own Milky Way galaxy. In this projection, the bluish Milky Way lies predominantly toward the upper middle and edges of the image.

  8. Extended Source/Galaxy All Sky 1

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This panoramic view of the entire sky reveals the distribution of galaxies beyond our Milky Way galaxy, which astronomers call extended sources, as observed by Two Micron All-Sky Survey. The image is constructed from a database of over 1.6 million galaxies listed in the survey's Extended Source Catalog; more than half of the galaxies have never before been catalogued. The image is a representation of the relative brightnesses of these million-plus galaxies, all observed at a wavelength of 2.2 microns.

    The brightest and nearest galaxies are represented in blue, and the faintest, most distant ones are in red. This color scheme gives insights into the three dimensional large-scale structure of the nearby universe with the brightest, closest clusters and superclusters showing up as the blue and bluish-white features. The dark band in this image shows the area of the sky where our Milky Way galaxy blocks our view of distant objects, which, in this projection, lies predominantly along the edges of the image.

  9. Positive deconvolution for superimposed extended source and point sources

    NASA Astrophysics Data System (ADS)

    Giovannelli, J.-F.; Coulais, A.

    2005-08-01

    The paper deals with the construction of images from visibilities acquired using aperture synthesis instruments: Fourier synthesis, deconvolution, and spectral interpolation/extrapolation. Its intended application is to specific situations in which the imaged object possesses two superimposed components: (i) an extended component together with (ii) a set of point sources. It is also specifically designed to the case of positive maps, and accounts for a known support. Its originality lies within joint estimation of the two components, coherently with data, properties of each component, positivity and possible support. We approach the subject as an inverse problem within a regularization framework: a regularized least-squares criterion is specifically proposed and the estimated maps are defined as its minimizer. We have investigated several options for the numerical minimization and we propose a new efficient algorithm based on augmented Lagrangian. Evaluation is carried out using simulated and real data (from radio interferometry) demonstrating the capability to accurately separate the two components.

  10. Numerical simulation and experimental verification of extended source interferometer

    NASA Astrophysics Data System (ADS)

    Hou, Yinlong; Li, Lin; Wang, Shanshan; Wang, Xiao; Zang, Haijun; Zhu, Qiudong

    2013-12-01

    Extended source interferometer, compared with the classical point source interferometer, can suppress coherent noise of environment and system, decrease dust scattering effects and reduce high-frequency error of reference surface. Numerical simulation and experimental verification of extended source interferometer are discussed in this paper. In order to provide guidance for the experiment, the modeling of the extended source interferometer is realized by using optical design software Zemax. Matlab codes are programmed to rectify the field parameters of the optical system automatically and get a series of interferometric data conveniently. The communication technique of DDE (Dynamic Data Exchange) was used to connect Zemax and Matlab. Then the visibility of interference fringes can be calculated through adding the collected interferometric data. Combined with the simulation, the experimental platform of the extended source interferometer was established, which consists of an extended source, interference cavity and image collection system. The decrease of high-frequency error of reference surface and coherent noise of the environment is verified. The relation between the spatial coherence and the size, shape, intensity distribution of the extended source is also verified through the analysis of the visibility of interference fringes. The simulation result is in line with the result given by real extended source interferometer. Simulation result shows that the model can simulate the actual optical interference of the extended source interferometer quite well. Therefore, the simulation platform can be used to guide the experiment of interferometer which is based on various extended sources.

  11. Detection of extended galactic sources with an underwater neutrino telescope

    SciTech Connect

    Leisos, A.; Tsirigotis, A. G.; Tzamarias, S. E.; Lenis, D.

    2014-11-18

    In this study we investigate the discovery capability of a Very Large Volume Neutrino Telescope to Galactic extended sources. We focus on the brightest HESS gamma rays sources which are considered also as very high energy neutrino emitters. We use the unbinned method taking into account both the spatial and the energy distribution of high energy neutrinos and we investigate parts of the Galactic plane where nearby potential neutrino emitters form neutrino source clusters. Neutrino source clusters as well as isolated neutrino sources are combined to estimate the observation period for 5 sigma discovery of neutrino signals from these objects.

  12. High-resolution extended source optical coherence tomography.

    PubMed

    Yu, Xiaojun; Liu, Xinyu; Chen, Si; Luo, Yuemei; Wang, Xianghong; Liu, Linbo

    2015-10-01

    High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a novel imaging system that achieves enhanced sensitivity without axial resolution degradation by the use of a spectrally encoded extended source (SEES) technique; it allows larger sample power without exceeding the maximum permissible exposure (MPE). In this study, we demonstrate a high-resolution extended source (HRES) OCT system, which is capable of providing a transverse resolution of 4.4 µm and an axial resolution of 2.1 µm in air with the SEES technique. We first theoretically show a sensitivity advantage of 6-dB of the HRES-OCT over that of its point source counterpart using numerical simulations, and then experimentally validate the applicability of the SEES technique to high-resolution OCT (HR-OCT) by comparing the HRES-OCT with an equivalent point-source system. In the HRES-OCT system, a dispersive prism was placed in the infinity space of the sample arm optics to spectrally extend the visual angle (angular subtense) of the light source to 10.3 mrad. This extended source allowed ~4 times larger MPE than its point source counterpart, which results in an enhancement of ~6 dB in sensitivity. Specifically, to solve the unbalanced dispersion between the sample and the reference arm optics, we proposed easy and efficient methods for system calibration and dispersion correction, respectively. With a maximum scanning speed reaching up to 60K A-lines/s, we further conducted imaging experiments with HRES-OCT using the human fingertip in vivo and the swine eye tissues ex vivo. Results demonstrate that the HRES-OCT is able to achieve significantly larger penetration depth than its conventional point source OCT counterpart.

  13. Brilliant high harmonic sources with extended cut-off

    SciTech Connect

    Seres, Josef; Spielmann, Christian; Seres, Enikoe

    2010-02-02

    The most challenging application of time resolved spectroscopy is to directly watch the structural and electronic dynamics. Here we present several ways for realizing laser driven x-ray sources, offering atomic spatial and temporal resolution. Our approaches are based on high harmonic generation and include quasi-phase matching in two successive gas jets, extending the cut-off by high harmonic generation in an ion channel, and amplification of HHG in a plasma based amplifier.

  14. Limit of concentration for cylindrical concentrators under extended light sources.

    PubMed

    Miñano, J C; Luque, A

    1983-08-15

    Cylindrical concentrators illuminated by an extended source with an arbitrary distribution of radiance are analyzed taking into account basic properties derived from the Fermat principle and not from the specific concentrator shape. The upper limit of concentration achievable with this type of concentrator is obtained and it is found to be lower than that of general (3-D) concentrators. Cylindrical compound parabolic concentrators are analyzed in the light of this theory, and it is shown that they achieve the highest optical concentration possible for a cylindrical concentrator. PMID:18196152

  15. Modeling threshold detection and search for point and extended sources

    NASA Astrophysics Data System (ADS)

    Friedman, Melvin

    2016-05-01

    This paper deals with three separate topics. 1)The Berek extended object threshold detection model is described, calibrated against a portion of Blackwell's 1946 naked eye threshold detection data for extended objects against an unstructured background, and then the remainder of Blackwell's data is used to verify and validate the model. A range equation is derived from Berek's model which allows threshold detection range to be predicted for extended to point objects against an un-cluttered background as a function of target size and adapting luminance levels. The range equation is then used to model threshold detection of stationary reflective and self-luminous targets against an uncluttered background. 2) There is uncertainty whether Travnikova's search data for point source detection against an un-cluttered background is described by Rayleigh or exponential distributions. A model which explains the Rayleigh distribution for barely perceptible objects and the exponential distribution for brighter objects is given. 3) A technique is presented which allows a specific observer's target acquisition capability to be characterized. Then a model is presented which describes how individual target acquisition probability grows when a specific observer or combination of specific observers search for targets. Applications for the three topics are discussed.

  16. Extending Marine Species Distribution Maps Using Non-Traditional Sources

    PubMed Central

    Moretzsohn, Fabio; Gibeaut, James

    2015-01-01

    Abstract Background Traditional sources of species occurrence data such as peer-reviewed journal articles and museum-curated collections are included in species databases after rigorous review by species experts and evaluators. The distribution maps created in this process are an important component of species survival evaluations, and are used to adapt, extend and sometimes contract polygons used in the distribution mapping process. New information During an IUCN Red List Gulf of Mexico Fishes Assessment Workshop held at The Harte Research Institute for Gulf of Mexico Studies, a session included an open discussion on the topic of including other sources of species occurrence data. During the last decade, advances in portable electronic devices and applications enable 'citizen scientists' to record images, location and data about species sightings, and submit that data to larger species databases. These applications typically generate point data. Attendees of the workshop expressed an interest in how that data could be incorporated into existing datasets, how best to ascertain the quality and value of that data, and what other alternate data sources are available. This paper addresses those issues, and provides recommendations to ensure quality data use. PMID:25941453

  17. Point-source CO2 emission estimation from airborne sampled CO2 mass density: a case study for an industrial plant in Biganos, Southern France.

    NASA Astrophysics Data System (ADS)

    Carotenuto, Federico; Gioli, Beniamino; Toscano, Piero; Zaldei, Alessandro; Miglietta, Franco

    2013-04-01

    One interesting aspect in the airborne sampling of ground emissions of all types (from CO2 to particulate matter) is the ability to understand the source from which these emissions originated and, therefore, obtain an estimation of that ground source's strength. Recently an aerial campaign has been conducted in order to sample emissions coming from a paper production plant in Biganos (France). The campaign made use of a Sky Arrow ERA (Environmental Research Aircraft) equipped with a mobile flux platform system. This latter system couples (among the various instrumentation) a turbulence probe (BAT) and a LICOR 7500 open-path infra-red gas analyzer that also enables the estimation of high-resolution fluxes of different scalars via the spatial-integrated eddy-covariance technique. Aircraft data showed a marked increase in CO2 mass density downwind the industrial area, while vertical profiles samplings showed that concentrations were changing with altitude. The estimation of the CO2 source was obtained using a simple mass balance approach, that is, by integrating the product of CO2 concentration and the mass flow rate through a cross-sectional area downwind of the point source. The results were compared with those obtained by means of a "forward-mode" Lagrangian dispersion model operated iteratively. CO2 source strength were varied at each iteration to obtain an optimal convergence between the modeled atmospheric concentrations and the concentration data observed by the aircraft. The procedure makes use of wind speed and atmospheric turbulence data which are directly measured by the BAT probe at different altitudes. The two methods provided comparable estimates of the CO2 source thus providing a substantial validation of the model-based iterative dispersion procedure. We consider that this data-model integration approach involving aircraft surveys and models may substantially enhance the estimation of point and area sources of any scalar, even in more complex

  18. ATLBS EXTENDED SOURCE SAMPLE: THE EVOLUTION IN RADIO SOURCE MORPHOLOGY WITH FLUX DENSITY

    SciTech Connect

    Saripalli, L.; Subrahmanyan, R.; Thorat, K.; Ekers, R. D.; Hunstead, R. W.; Johnston, H. M.; Sadler, E. M.

    2012-04-01

    Based on the Australia Telescope Low Brightness Survey (ATLBS) we present a sample of extended radio sources and derive morphological properties of faint radio sources. One hundred nineteen radio galaxies form the ATLBS Extended Source Sample (ATLBS-ESS) consisting of all sources exceeding 30'' in extent and integrated flux densities exceeding 1 mJy. We give structural details along with information on galaxy identifications and source classifications. The ATLBS-ESS, unlike samples with higher flux-density limits, has almost equal fractions of FR-I and FR-II radio galaxies, with a large fraction of the FR-I population exhibiting 3C31-type structures. Significant asymmetry in lobe extents appears to be a common occurrence in the ATLBS-ESS FR-I sources compared with FR-II sources. We present a sample of 22 FR-Is at z > 0.5 with good structural information. The detection of several giant radio sources, with size exceeding 0.7 Mpc, at z > 1 suggests that giant radio sources are not less common at high redshifts. The ESS also includes a sample of 28 restarted radio galaxies. The relative abundance of dying and restarting sources is indicative of a model where radio sources undergo episodic activity in which an active phase is followed by a brief dying phase that terminates with restarting of the central activity; in any massive elliptical a few such activity cycles wherein adjacent events blend may constitute the lifetime of a radio source and such bursts of blended activity cycles may be repeated over the age of the host. The ATLBS-ESS includes a 2 Mpc giant radio galaxy with the lowest surface brightness lobes known to date.

  19. An extended superhot solar flare X-ray source

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.; Ohki, K. I.; Tsuneta, S.

    1985-01-01

    A superhot hard X-ray source in a solar flare occulted by the solar limb was identified. Its hard X-ray image was found to show great horizontal extent but little vertical extent. An H alpha brightening at the same limb position about an hour later suggests a multi-component loop prominence system, so that it appears that a superhot source can evolve in the same manner as a normal solar soft X-ray source. The assignment of plausiable values to physical parameters in the source suggests (from the simplest form of classical thermal-conduction theory) that either new physics will be required to suppress conduction, or else that gradual energy release well after the impulsive phase of the flare must occur. In this respect too, the superhot source appears to resemble ordinary soft X-ray sources, except of course that its temperature is higher.

  20. An extended superhot solar flare X-ray source

    NASA Astrophysics Data System (ADS)

    Hudson, H. S.; Ohki, K. I.; Tsuneta, S.

    1985-08-01

    A superhot hard X-ray source in a solar flare occulted by the solar limb was identified. Its hard X-ray image was found to show great horizontal extent but little vertical extent. An H alpha brightening at the same limb position about an hour later suggests a multi-component loop prominence system, so that it appears that a superhot source can evolve in the same manner as a normal solar soft X-ray source. The assignment of plausiable values to physical parameters in the source suggests (from the simplest form of classical thermal-conduction theory) that either new physics will be required to suppress conduction, or else that gradual energy release well after the impulsive phase of the flare must occur. In this respect too, the superhot source appears to resemble ordinary soft X-ray sources, except of course that its temperature is higher.

  1. Source self-mixing in the detection of extended incoherent sources. [in optical heterodyne radiometry

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1975-01-01

    We consider the self-beating of incoherent light from an extended source at a wideband photomixer. The intermediate frequency mean squared current is found to be proportional to the product of the direct detected source power and the power within the IF bandpass about the optical frequency and within the heterodyne field of view. Thus the ratio of the heterodyne signal to self-beating power is proportional to the ratio of local oscillator power to direct detected power. This ratio is usually large for systems employing efficient local oscillators that generate shot-noise-limited operation. In less efficient systems, such as those employing tunable diode lasers, the effects of self-mixing may be significant.

  2. Direct design of aspherical lenses for extended non-Lambertian sources in two-dimensional geometry.

    PubMed

    Wu, Rengmao; Hua, Hong; Benítez, Pablo; Miñano, Juan C

    2015-07-01

    Illumination design for extended sources is very important for practical applications. The existing direct methods that are all developed for extended Lambertian sources are not applicable to extended non-Lambertian sources whose luminance is a function of position and direction. What we present in this Letter is to our knowledge the first direct method for extended non-Lambertian sources. In this method, the edge rays and the interior rays are both used, and the output intensity at a given direction is calculated to be the integral of the luminance function of all the outgoing rays at this direction. No cumbersome iterative illuminance compensation is needed. Two examples are presented to demonstrate the elegance of this method in prescribed intensity design for extended non-Lambertian sources in two-dimensional geometry. PMID:26125361

  3. Direct design of aspherical lenses for extended non-Lambertian sources in two-dimensional geometry.

    PubMed

    Wu, Rengmao; Hua, Hong; Benítez, Pablo; Miñano, Juan C

    2015-07-01

    Illumination design for extended sources is very important for practical applications. The existing direct methods that are all developed for extended Lambertian sources are not applicable to extended non-Lambertian sources whose luminance is a function of position and direction. What we present in this Letter is to our knowledge the first direct method for extended non-Lambertian sources. In this method, the edge rays and the interior rays are both used, and the output intensity at a given direction is calculated to be the integral of the luminance function of all the outgoing rays at this direction. No cumbersome iterative illuminance compensation is needed. Two examples are presented to demonstrate the elegance of this method in prescribed intensity design for extended non-Lambertian sources in two-dimensional geometry.

  4. Direct design of aspherical lenses for extended non-Lambertian sources in two-dimensional geometry

    PubMed Central

    Wu, Rengmao; Hua, Hong; Benítez, Pablo; Miñano, Juan C.

    2016-01-01

    Illumination design for extended sources is very important for practical applications. The existing direct methods that are all developed for extended Lambertian sources are not applicable to extended non-Lambertian sources whose luminance is a function of position and direction. What we present in this Letter is to our knowledge the first direct method for extended non-Lambertian sources. In this method, the edge rays and the interior rays are both used, and the output intensity at a given direction is calculated to be the integral of the luminance function of all the outgoing rays at this direction. No cumbersome iterative illuminance compensation is needed. Two examples are presented to demonstrate the elegance of this method in prescribed intensity design for extended non-Lambertian sources in two-dimensional geometry. PMID:26125361

  5. Extended radio source in the center of M31

    SciTech Connect

    Hjellming, R.M.; Smarr, L.L.

    1982-06-01

    Radio observations of the central 1/sup 0/ x 1/sup 0/ region of the Andromeda Nebula (M31), made with the 1 km configuration of the NRAO VLA, show that at 1465 MHz the central radio source is nearly spherical and 2 kpc (10') in diameter, with a brightness distribution roughly proportional to exp(-R/1.'1), where R is the angular distance from the radio maximum located 20'' from the nucleus at the position angle of 70/sup 0/. The broad structure of this object may be due to a bulge population of many weak supernova remnants or to a cosmic-ray electron-dominated galactic wind.

  6. Atomic hydrogen beam source: a convenient, extended cavity, microwave discharge design.

    PubMed

    Murphy, E J; Brophy, J H

    1979-05-01

    An extended cavity design of a microwave discharge source for production of intense beams of atomic, radical, and metastable species in vacuo is described. The extended cavity enables the discharge to be run at the beam source nozzle while the power connection and tuning elements remain conveniently outside the apparatus. This design minimizes wall recombination losses to produce intense atomic hydrogen beams with considerably less engineering than previous discharge sources.

  7. The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. III. The Reddest Extended Sources in WISE

    NASA Astrophysics Data System (ADS)

    Griffith, Roger L.; Wright, Jason T.; Maldonado, Jessica; Povich, Matthew S.; Sigurđsson, Steinn; Mullan, Brendan

    2015-04-01

    Nearby Type iii (galaxy-spanning) Kardashev supercivilizations would have high mid-infrared (MIR) luminosities. We have used the Wide-field Infrared Survey Explorer (WISE) to survey ∼ 1× {{10}5} galaxies for extreme MIR emission, 1 × 103 times more galaxies than the only previous such search. We have calibrated the WISE All-sky Catalog pipeline products to improve their photometry for extended sources. We present 563 extended sources with |b|≥slant 10 and red MIR colors, having visually vetted them to remove artifacts. No galaxies in our sample host an alien civilization reprocessing more than 85% of its starlight into the MIR, and only 50 galaxies, including Arp 220, have MIR luminosities consistent with \\gt 50% reprocessing. Ninety of these (likely) extragalactic sources have little literature presence; in most cases, they are likely barely resolved galaxies or pairs of galaxies undergoing large amounts of star formation. Five are new to science and deserve further study. The Be star 48 Librae sits within a MIR nebula, and we suggest that it may be creating dust. WISE, 2MASS, and Spitzer imagery shows that IRAS 04287+6444 is consistent with a previously unnoticed, heavily extinguished cluster of young stellar objects. We identify five “passive” (i.e., red) spiral galaxies with unusually high MIR and low NUV luminosity. We search a set of H i dark galaxies for MIR emission and find none. These 90 poorly understood sources and 5 anomalous passive spirals deserve follow-up via both SETI and conventional astrophysics.

  8. General Purpose Kernel Integration Shielding Code System-Point and Extended Gamma-Ray Sources.

    1981-06-11

    PELSHIE3 calculates dose rates from gamma-emitting sources with different source geometries and shielding configurations. Eight source geometries are provided and are called by means of geometry index numbers. Gamma-emission characteristics for 134 isotopes, attenuation coefficients for 57 elements or shielding materials and Berger build-up parameters for 17 shielding materials can be obtained from a direct access data library by specifying only the appropriate library numbers. A different option allows these data to be read frommore » cards. For extended sources, constant source strengths as well as exponential and Bessel function source strength distributions are allowed in most cases.« less

  9. Search for Spatially Extended Fermi-LAT Sources Using Two Years of Data

    SciTech Connect

    Lande, Joshua; Ackermann, Markus; Allafort, Alice; Ballet, Jean; Bechtol, Keith; Burnett, Toby; Cohen-Tanugi, Johann; Drlica-Wagner, Alex; Funk, Stefan; Giordano, Francesco; Grondin, Marie-Helene; Kerr, Matthew; Lemoine-Goumard, Marianne

    2012-07-13

    Spatial extension is an important characteristic for correctly associating {gamma}-ray-emitting sources with their counterparts at other wavelengths and for obtaining an unbiased model of their spectra. We present a new method for quantifying the spatial extension of sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi). We perform a series of Monte Carlo simulations to validate this tool and calculate the LAT threshold for detecting the spatial extension of sources. We then test all sources in the second Fermi -LAT catalog (2FGL) for extension. We report the detection of seven new spatially extended sources.

  10. Design methodology for micro-discrete planar optics with minimum illumination loss for an extended source.

    PubMed

    Shim, Jongmyeong; Park, Changsu; Lee, Jinhyung; Kang, Shinill

    2016-08-01

    Recently, studies have examined techniques for modeling the light distribution of light-emitting diodes (LEDs) for various applications owing to their low power consumption, longevity, and light weight. The energy mapping technique, a design method that matches the energy distributions of an LED light source and target area, has been the focus of active research because of its design efficiency and accuracy. However, these studies have not considered the effects of the emitting area of the LED source. Therefore, there are limitations to the design accuracy for small, high-power applications with a short distance between the light source and optical system. A design method for compensating for the light distribution of an extended source after the initial optics design based on a point source was proposed to overcome such limits, but its time-consuming process and limited design accuracy with multiple iterations raised the need for a new design method that considers an extended source in the initial design stage. This study proposed a method for designing discrete planar optics that controls the light distribution and minimizes the optical loss with an extended source and verified the proposed method experimentally. First, the extended source was modeled theoretically, and a design method for discrete planar optics with the optimum groove angle through energy mapping was proposed. To verify the design method, design for the discrete planar optics was achieved for applications in illumination for LED flash. In addition, discrete planar optics for LED illuminance were designed and fabricated to create a uniform illuminance distribution. Optical characterization of these structures showed that the design was optimal; i.e., we plotted the optical losses as a function of the groove angle, and found a clear minimum. Simulations and measurements showed that an efficient optical design was achieved for an extended source.

  11. Design methodology for micro-discrete planar optics with minimum illumination loss for an extended source.

    PubMed

    Shim, Jongmyeong; Park, Changsu; Lee, Jinhyung; Kang, Shinill

    2016-08-01

    Recently, studies have examined techniques for modeling the light distribution of light-emitting diodes (LEDs) for various applications owing to their low power consumption, longevity, and light weight. The energy mapping technique, a design method that matches the energy distributions of an LED light source and target area, has been the focus of active research because of its design efficiency and accuracy. However, these studies have not considered the effects of the emitting area of the LED source. Therefore, there are limitations to the design accuracy for small, high-power applications with a short distance between the light source and optical system. A design method for compensating for the light distribution of an extended source after the initial optics design based on a point source was proposed to overcome such limits, but its time-consuming process and limited design accuracy with multiple iterations raised the need for a new design method that considers an extended source in the initial design stage. This study proposed a method for designing discrete planar optics that controls the light distribution and minimizes the optical loss with an extended source and verified the proposed method experimentally. First, the extended source was modeled theoretically, and a design method for discrete planar optics with the optimum groove angle through energy mapping was proposed. To verify the design method, design for the discrete planar optics was achieved for applications in illumination for LED flash. In addition, discrete planar optics for LED illuminance were designed and fabricated to create a uniform illuminance distribution. Optical characterization of these structures showed that the design was optimal; i.e., we plotted the optical losses as a function of the groove angle, and found a clear minimum. Simulations and measurements showed that an efficient optical design was achieved for an extended source. PMID:27505823

  12. Freeform lens design using a complementary optimization method for uniform illumination with extended LED light sources

    NASA Astrophysics Data System (ADS)

    Wang, Te-Yuan; Chen, Jin-Jia; Huang, Kuang-Lung; Wang, Chuen-Ching

    2014-11-01

    We propose a complementary optimization method to design a freeform lens for uniform illumination with extended LED sources. With this method, a primary freeform lens is first constructed based on a source-target energy mapping approach; then a complementary illuminance on the target plane is introduced to optimize the primary freeform lens so that it can produce uniform illumination with an extended COB LED. The computer simulation results show that the illuminance uniformity of the optimized lens can be improved nearby 30% as compared with that of the primary lens; meanwhile, the optical efficiency achieves above 94%.

  13. Automated detection of extended sources in radio maps: progress from the SCORPIO survey

    NASA Astrophysics Data System (ADS)

    Riggi, S.; Ingallinera, A.; Leto, P.; Cavallaro, F.; Bufano, F.; Schillirò, F.; Trigilio, C.; Umana, G.; Buemi, C. S.; Norris, R. P.

    2016-08-01

    Automated source extraction and parametrization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper, we present a new algorithm, called CAESAR (Compact And Extended Source Automated Recognition), to detect and parametrize extended sources in radio interferometric maps. It is based on a pre-filtering stage, allowing image denoising, compact source suppression and enhancement of diffuse emission, followed by an adaptive superpixel clustering stage for final source segmentation. A parametrization stage provides source flux information and a wide range of morphology estimators for post-processing analysis. We developed CAESAR in a modular software library, also including different methods for local background estimation and image filtering, along with alternative algorithms for both compact and diffuse source extraction. The method was applied to real radio continuum data collected at the Australian Telescope Compact Array (ATCA) within the SCORPIO project, a pathfinder of the Evolutionary Map of the Universe (EMU) survey at the Australian Square Kilometre Array Pathfinder (ASKAP). The source reconstruction capabilities were studied over different test fields in the presence of compact sources, imaging artefacts and diffuse emission from the Galactic plane and compared with existing algorithms. When compared to a human-driven analysis, the designed algorithm was found capable of detecting known target sources and regions of diffuse emission, outperforming alternative approaches over the considered fields.

  14. THE 2MASS REDSHIFT SURVEY-DESCRIPTION AND DATA RELEASE

    SciTech Connect

    Huchra, John P.; Berlind, Perry; Calkins, Michael; Falco, Emilio; Mink, Jessica D.; Tokarz, Susan; Macri, Lucas M.; Masters, Karen L.; Jarrett, Thomas H.; Crook, Aidan C.; Cutri, Roc; Erdogdu, Pirin; Lahav, Ofer; George, Teddy; Hutcheson, Conrad M.; Mader, Jeff; Martimbeau, Nathalie; Schneider, Stephen; Skrutskie, Michael; Westover, Michael E-mail: karen.masters@port.ac.uk

    2012-04-01

    We present the results of the 2MASS Redshift Survey (2MRS), a ten-year project to map the full three-dimensional distribution of galaxies in the nearby universe. The Two Micron All Sky Survey (2MASS) was completed in 2003 and its final data products, including an extended source catalog (XSC), are available online. The 2MASS XSC contains nearly a million galaxies with K{sub s} {<=} 13.5 mag and is essentially complete and mostly unaffected by interstellar extinction and stellar confusion down to a galactic latitude of |b| = 5 Degree-Sign for bright galaxies. Near-infrared wavelengths are sensitive to the old stellar populations that dominate galaxy masses, making 2MASS an excellent starting point to study the distribution of matter in the nearby universe. We selected a sample of 44,599 2MASS galaxies with K{sub s} {<=} 11.75 mag and |b| {>=} 5 Degree-Sign ({>=}8 Degree-Sign toward the Galactic bulge) as the input catalog for our survey. We obtained spectroscopic observations for 11,000 galaxies and used previously obtained velocities for the remainder of the sample to generate a redshift catalog that is 97.6% complete to well-defined limits and covers 91% of the sky. This provides an unprecedented census of galaxy (baryonic mass) concentrations within 300 Mpc. Earlier versions of our survey have been used in a number of publications that have studied the bulk motion of the Local Group, mapped the density and peculiar velocity fields out to 50 h{sup -1} Mpc, detected galaxy groups, and estimated the values of several cosmological parameters. Additionally, we present morphological types for a nearly complete sub-sample of 20,860 galaxies with K{sub s} {<=} 11.25 mag and |b| {>=} 10 Degree-Sign .

  15. Extending the ICRF to Higher Radio Frequencies: Imaging and Source Structure

    NASA Technical Reports Server (NTRS)

    Boboltz, David A.; Fey, Alan L.; Charlot, Patrick; Fomalont, Edward B.; Lanyi, Gabor E.; Zhang, Li-Wei

    2004-01-01

    We present imaging results and source structure analysis of extragalactic radio sources observed using the Very Long Baseline Array (VLBA) at 24 GHz and 43 GHz as part of an ongoing NASA, USNO, NRAO and Bordeaux Observatory collaboration to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies. The K/Q-band image database now includes images of 108 sources at 43 GHz (Q-braid) and images of 230 sources at 24 GHz (K-band). Preliminary analysis of the observations taken to date shows that the sources are generally more compact as one goes from the ICRF frequency of 8.4 GHz to 24 GHz. This result is consistent with the standard theory of compact extragalactic radio sources and suggests that reference frames defined at these higher radio frequencies will be less susceptible to the effects of intrinsic source structure than those defined at lower frequencies.

  16. Source Similarity and Social Media Health Messages: Extending Construal Level Theory to Message Sources.

    PubMed

    Young, Rachel

    2015-09-01

    Social media users post messages about health goals and behaviors to online social networks. Compared with more traditional sources of health communication such as physicians or health journalists, peer sources are likely to be perceived as more socially close or similar, which influences how messages are processed. This experimental study uses construal level theory of psychological distance to predict how mediated health messages from peers influence health-related cognition and behavioral intention. Participants were exposed to source cues that identified peer sources as being either highly attitudinally and demographically similar to or different from participants. As predicted by construal level theory, participants who perceived sources of social media health messages as highly similar listed a greater proportion of beliefs about the feasibility of health behaviors and a greater proportion of negative beliefs, while participants who perceived sources as more dissimilar listed a greater proportion of positive beliefs about the health behaviors. Results of the study could be useful in determining how health messages from peers could encourage individuals to set realistic health goals. PMID:26348816

  17. Source Similarity and Social Media Health Messages: Extending Construal Level Theory to Message Sources.

    PubMed

    Young, Rachel

    2015-09-01

    Social media users post messages about health goals and behaviors to online social networks. Compared with more traditional sources of health communication such as physicians or health journalists, peer sources are likely to be perceived as more socially close or similar, which influences how messages are processed. This experimental study uses construal level theory of psychological distance to predict how mediated health messages from peers influence health-related cognition and behavioral intention. Participants were exposed to source cues that identified peer sources as being either highly attitudinally and demographically similar to or different from participants. As predicted by construal level theory, participants who perceived sources of social media health messages as highly similar listed a greater proportion of beliefs about the feasibility of health behaviors and a greater proportion of negative beliefs, while participants who perceived sources as more dissimilar listed a greater proportion of positive beliefs about the health behaviors. Results of the study could be useful in determining how health messages from peers could encourage individuals to set realistic health goals.

  18. History of Science and Conceptual Change: The Formation of Shadows by Extended Light Sources

    ERIC Educational Resources Information Center

    Dedes, Christos; Ravanis, Konstantinos

    2009-01-01

    This study investigates the effectiveness of a teaching conflict procedure whose purpose was the transformation of the representations of 12-16-year-old pupils in Greece concerning light emission and shadow formation by extended light sources. The changes observed during the children's effort to destabilize and reorganise their representations…

  19. Water-extended polyester neutron shield for a 252Cf neutron source.

    PubMed

    Vega-Carrillo, H R; Manzanares-Acuña, E; Hernández-Dávila, V M; Gallego, E; Lorente, A; Donaire, I

    2007-01-01

    A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester was carried out. During calculations, (252)Cf and shielding were modelled and the neutron spectra as well as the H(10) were calculated in four sites. The calculation was extended to include a water shielding, the source in vacuum and in air. Besides neutron shielding characteristics, the Kerma in air due to gammas emitted by (252)Cf and due to capture gamma rays in the shielding were included.

  20. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operationa)

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Alessi, J.; Faircloth, D.; Gerardin, A.; Kalvas, T.; Pereira, H.; Sgobba, S.

    2012-02-01

    Linac4 accelerator of Centre Européen de Recherches Nucléaires is under construction and a RF-driven H- ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H-, electrons, and Cs- ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  1. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation

    SciTech Connect

    Lettry J.; Alessi J.; Faircloth, D.; Gerardin, A.; Kalvas, T.; Pereira, H.; Sgobba, S.

    2012-02-23

    Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  2. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation.

    PubMed

    Lettry, J; Alessi, J; Faircloth, D; Gerardin, A; Kalvas, T; Pereira, H; Sgobba, S

    2012-02-01

    Linac4 accelerator of Centre Européen de Recherches Nucléaires is under construction and a RF-driven H(-) ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H(-), electrons, and Cs(-) ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  3. Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation

    SciTech Connect

    Lettry, J.; Gerardin, A.; Pereira, H.; Sgobba, S.; Alessi, J.; Faircloth, D.; Kalvas, T.

    2012-02-15

    Linac4 accelerator of Centre Europeen de Recherches Nucleaires is under construction and a RF-driven H{sup -} ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended operation periods. A metallurgical investigation of an ISIS ion source is presented. The origin of the deformation is twofold: Molybdenum sputtering by cesium ions digs few tenths of mm cavities while a growth of molybdenum is observed in the immediate vicinity. The molybdenum growth under hydrogen atmosphere is hard and loosely bound to the bulk. It is, therefore, likely to peel off and be transported within the plasma volume. The observation of the cathode, anode, and extraction electrodes of the magnetron source operated at BNL for two years are presented. A beam simulation of H{sup -}, electrons, and Cs{sup -} ions was performed with the IBSimu code package to qualitatively explain the observations. This paper describes the operation conditions of the ion sources and discusses the metallurgical analysis and beam simulation results.

  4. Waveform inversion of volcano-seismic signals for an extended source

    USGS Publications Warehouse

    Nakano, M.; Kumagai, H.; Chouet, B.; Dawson, P.

    2007-01-01

    We propose a method to investigate the dimensions and oscillation characteristics of the source of volcano-seismic signals based on waveform inversion for an extended source. An extended source is realized by a set of point sources distributed on a grid surrounding the centroid of the source in accordance with the source geometry and orientation. The source-time functions for all point sources are estimated simultaneously by waveform inversion carried out in the frequency domain. We apply a smoothing constraint to suppress short-scale noisy fluctuations of source-time functions between adjacent sources. The strength of the smoothing constraint we select is that which minimizes the Akaike Bayesian Information Criterion (ABIC). We perform a series of numerical tests to investigate the capability of our method to recover the dimensions of the source and reconstruct its oscillation characteristics. First, we use synthesized waveforms radiated by a kinematic source model that mimics the radiation from an oscillating crack. Our results demonstrate almost complete recovery of the input source dimensions and source-time function of each point source, but also point to a weaker resolution of the higher modes of crack oscillation. Second, we use synthetic waveforms generated by the acoustic resonance of a fluid-filled crack, and consider two sets of waveforms dominated by the modes with wavelengths 2L/3 and 2W/3, or L and 2L/5, where W and L are the crack width and length, respectively. Results from these tests indicate that the oscillating signature of the 2L/3 and 2W/3 modes are successfully reconstructed. The oscillating signature of the L mode is also well recovered, in contrast to results obtained for a point source for which the moment tensor description is inadequate. However, the oscillating signature of the 2L/5 mode is poorly recovered owing to weaker resolution of short-scale crack wall motions. The triggering excitations of the oscillating cracks are successfully

  5. Detection of Extended Thermal Infrared Emission around the Vega-like Source HD 141569.

    PubMed

    Fisher; Telesco; Piña; Knacke; Wyatt

    2000-04-01

    We report the detection of extended IR emission at 10.8 and 18.2 µm around the Vega-like source HD 141569. Mid-IR imaging with OSCIR on Keck II shows emission from dust extending out to 100 AU from the B9.5 Ve star. Our modeling of the dust places an upper limit of approximately 2 µm on the diameter of the mid-IR-emitting particles if they are Mie spheres of astronomical silicates. Comparison of our mid-IR images to the near-IR (1.1 µm) NICMOS images of HD 141569 (Weinberger et al. 1999) shows that the mid-IR emission originates at smaller distances from the star than the scattered near-IR light, as also previously observed for the archetype Vega-like source beta Pictoris. PMID:10715244

  6. Extending the search for neutrino point sources with IceCube above the horizon.

    PubMed

    Abbasi, R; Abdou, Y; Abu-Zayyad, T; Adams, J; Aguilar, J A; Ahlers, M; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Bazo Alba, J L; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K-H; Benabderrahmane, M L; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bissok, M; Blaufuss, E; Boersma, D J; Bohm, C; Botner, O; Bradley, L; Braun, J; Breder, D; Carson, M; Castermans, T; Chirkin, D; Christy, B; Clem, J; Cohen, S; Cowen, D F; D'Agostino, M V; Danninger, M; Day, C T; De Clercq, C; Demirörs, L; Depaepe, O; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dreyer, J; Dumm, J P; Duvoort, M R; Edwards, W R; Ehrlich, R; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Feusels, T; Filimonov, K; Finley, C; Foerster, M M; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Ganugapati, R; Gerhardt, L; Gladstone, L; Goldschmidt, A; Goodman, J A; Gozzini, R; Grant, D; Griesel, T; Gross, A; Grullon, S; Gunasingha, R M; Gurtner, M; Ha, C; Hallgren, A; Halzen, F; Han, K; Hanson, K; Hasegawa, Y; Helbing, K; Herquet, P; Hickford, S; Hill, G C; Hoffman, K D; Homeier, A; Hoshina, K; Hubert, D; Huelsnitz, W; Hülss, J-P; Hulth, P O; Hultqvist, K; Hussain, S; Imlay, R L; Inaba, M; Ishihara, A; Jacobsen, J; Japaridze, G S; Johansson, H; Joseph, J M; Kampert, K-H; Kappes, A; Karg, T; Karle, A; Kelley, J L; Kemming, N; Kenny, P; Kiryluk, J; Kislat, F; Klein, S R; Knops, S; Kohnen, G; Kolanoski, H; Köpke, L; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Krings, T; Kroll, G; Kuehn, K; Kuwabara, T; Labare, M; Lafebre, S; Laihem, K; Landsman, H; Lauer, R; Lehmann, R; Lennarz, D; Lundberg, J; Lünemann, J; Madsen, J; Majumdar, P; Maruyama, R; Mase, K; Matis, H S; McParland, C P; Meagher, K; Merck, M; Mészáros, P; Meures, T; Middell, E; Milke, N; Miyamoto, H; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Niessen, P; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; Ono, M; Panknin, S; Patton, S; Paul, L; Pérez de los Heros, C; Petrovic, J; Piegsa, A; Pieloth, D; Pohl, A C; Porrata, R; Potthoff, N; Price, P B; Prikockis, M; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Rizzo, A; Rodrigues, J P; Roth, P; Rothmaier, F; Rott, C; Roucelle, C; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H-G; Sarkar, S; Schatto, K; Schlenstedt, S; Schmidt, T; Schneider, D; Schukraft, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Slipak, A; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stephens, G; Stezelberger, T; Stokstad, R G; Stoufer, M C; Stoyanov, S; Strahler, E A; Straszheim, T; Sullivan, G W; Swillens, Q; Taboada, I; Tamburro, A; Tarasova, O; Tepe, A; Ter-Antonyan, S; Terranova, C; Tilav, S; Toale, P A; Tooker, J; Tosi, D; Turcan, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; van Santen, J; Voigt, B; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Wiedemann, A; Wikström, G; Williams, D R; Wischnewski, R; Wissing, H; Woschnagg, K; Xu, C; Xu, X W; Yodh, G; Yoshida, S

    2009-11-27

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies. PMID:20366087

  7. Extending the search for neutrino point sources with IceCube above the horizon

    SciTech Connect

    IceCube Collaboration; Abbasi, R.

    2009-11-20

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This approach improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

  8. Optical design method of freeform lens for a high-power extended LED source

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Du, Naifeng; Wu, Yuefeng; Huang, Huamao

    2012-10-01

    In view of limitation for LED optical design method as ideal point source, a new uniform illumination optical design method of freeform lens for a high-power LED is present in the paper.By establishing an energy corresponding relationship between the extended LED source and the point illumination of the receiving surface, a freeform lens optical model achieving uniform illumination in target plane is obtained.The optical simulation results of uniform light intensity curve of the model are compared with the one designed by an approximate point source method. The results show that the new method can effectively overcome the shortages from the point source design.It is more accurately to control the correspondence relationship of light energy and the outgoing direction of light.The illumination uniformity of the freeform lens is greater than 75% and also meets the design requirements.

  9. From laboratory results to models: Polyoxymethylene as a parent of formaldehyde extended source in comet Halley

    NASA Astrophysics Data System (ADS)

    Cottin, H.; Benilan, Y.; Fray, N.; Gazeau, M.; Raulin, F.

    Measurements performed by the NMS mass spectrometer on board Giotto show that the formaldehyde density profile, as a function of the distance to the nucleus of comet Halley, cannot be explained only by a direct release of formaldehyde from the nucleus. Understanding this observation requires an additional source of formaldehyde, which is most commonly called "extended source". Such a phenomenon is also detected in comets Hyakutake and Hale-Bopp. Presence of Polyoxymethylene (POM-polymer of formaldehyde) has often been debated to interpret H2 CO extended source but until very recently important quantitative data were missing to allow an appropriate analysis of this hypothesis. Formaldehyde production rate from POM on solid grains is a function of several unknown parameters: the matrix in which POM is imbedded, the geometry of the grains, the chemical structure of the polymer, its photodegradation rate and its temperature. We have obtained experimental data concerning the photo and thermal degradation of POM and modelled the contribution of potential solid POM on dust particles to the gaseous phase. First results were presented in (Cottin et al., 2001) for a single size population of grains, and temperature as a free parameter. We have now extended our model to a more realistic grain population, based on actual measurements in Halley coma, for which velocity and temperature of each grain are a function of its size and composition. We have calculated the best fits to Giotto measurements and derived the amount of POM required to account H2 CO observation. The results show that the presence of a few percent in mass of solid POM on grains can provide a realistic explanation to the formaldehyde extended source observed in several comets. Even if the model still needs to be improved, for example to include different grains geometry, it can already be used to test other molecules like Hexamethylenetetramine (HMT) or poly-HCN against known extended sources such as CN, C2 or

  10. An extended soft X-ray source in Delphinus - H2027+19

    NASA Technical Reports Server (NTRS)

    Stern, R. A.; Walker, A. B. C.; Charles, P. A.; Nugent, J. J.; Garmire, G. P.

    1980-01-01

    A new extended soft X-ray source has been observed with the HEAO 1 A-2 experiment. The source, H2027+19, emits primarily in the 0.16-0.4 keV band with a total flux in this band of 2 x 10 to the -11th erg/sq cm s. It is found that both simple continuum and coronal plasma models provide good fits to the observed pulse-height spectrum. The most likely physical models are either that the source is an old supernova remnant or that it is a region of enhanced soft X-ray emission surrounding an H I cloud imbedded in a coronal plasma, as suggested by Hayakawa et al. (1979) for the Lupus Loop.

  11. Gravitational lensing of extended high-redshift sources by dark matter haloes

    NASA Astrophysics Data System (ADS)

    Perrotta, F.; Baccigalupi, C.; Bartelmann, M.; De Zotti, G.; Granato, G. L.

    2002-01-01

    High-redshift galaxies and quasi-stellar objects (QSOs) are most likely to be strongly lensed by intervening haloes between the source and the observer. In addition, a large fraction of lensed sources is expected to be seen in the submillimetre region, as a result of the enhanced magnification bias on the steep intrinsic number counts. We extend in three directions Blain's earlier study of this effect. First, we use a modification of the Press-Schechter mass function and detailed lens models to compute the magnification probability distribution. We compare the magnification cross-sections of populations of singular isothermal spheres and Navarro, Frenk & White (NFW) haloes and find that they are very similar, in contrast to the image-splitting statistics which were recently investigated in other studies. The distinction between the two types of density profile is therefore irrelevant for our purposes. Secondly, we discuss quantitatively the maximum magnification, μmax, that can be achieved for extended sources (galaxies) with realistic luminosity profiles, taking into account the possible ellipticity of the lensing potential. We find that μmax plausibly falls into the range 10-30 for sources of 1-10h-1kpc effective radius at redshifts within 1-4. Thirdly, we apply our model for the lensing magnification to a class of sources following the luminosity evolution typical for a unified scheme of QSO formation. As a result of the peculiar steepness of their intrinsic number counts, we find that the lensed source counts at a fiducial wave length of 850μm can exceed the unlensed counts by several orders of magnitude at flux densities >~100mJy, even with a conservative choice of the maximum magnification.

  12. Comparison of two programs in calculating electron output factors at extended source-surface distances.

    PubMed

    Hu, Yunfei; Lambert, Jonathan Andrew; Wang, Yang

    2016-01-01

    Monitor units (MUs) calculated by radiotherapy treatment planning systems need to be verified independently. At extended source-surface distances (SSDs), different output factors (OFs) can be given by different independent MU checking packages due to the calculation methods used and assumptions made within them. The accuracy of two software packages - RadCalc(®) (LifeLine Software Inc., Austin, USA) and eDatabook (Y. Wang, Radiation Oncology Institute, Sydney, AUS) - was determined by comparing the calculated OFs directly to measured OFs for a series of standard electron cutouts on an Elekta Synergy linear accelerator at standard and extended SSDs (100 cm and above). For the majority of the measurements made, eDatabook provided OFs closer to the measured value than RadCalc; however, in two cases, eDatabook was unable to provide a factor. RadCalc failed to calculate the OFs accurately at extended SSDs as its calculation is based on the assumption that the established effective-SSD curve can accurately predict the data where there are no measurements available. The accuracy of eDatabook is due to its use of a linear interpolation to determine the OF at an extended SSD when there are no measurement data available. PMID:27051172

  13. Stationary states of extended nonlinear Schrödinger equation with a source

    NASA Astrophysics Data System (ADS)

    Borich, M. A.; Smagin, V. V.; Tankeev, A. P.

    2007-02-01

    Structure of nonlinear stationary states of the extended nonlinear Schrödinger equation (ENSE) with a source has been analyzed with allowance for both third-order and nonlinearity dispersion. A new class of particular solutions (solitary waves) of the ENSe has been obtained. The scenario of the destruction of these states under the effect of an external perturbation has been investigated analytically and numerically. The results obtained can be used to interpret experimental data on the weakly nonlinear dynamics of the magnetostatic envelope in heterophase ferromagnet-insulator-metal, metal-insulator-ferromagnet-insulator-metal, and other similar structures and upon the simulation of nonlinear processes in optical systems.

  14. Observation of soft X-rays from extended sources. [such as Perseus star cluster

    NASA Technical Reports Server (NTRS)

    Catura, R. C.; Acton, L. W.

    1974-01-01

    Efforts were directed toward surveying several supernova remnants for the emission of soft X-rays. Rather than attempt to detect such faint X-ray emission, the program was redirected to observe the spectrum and angular structure of the extended X-ray source in the Perseus cluster of galaxies and the super-nova remnant Puppis A. An attempt was made to detect X-ray line emission from Puppis A with a Bragg crystal spectrometer. Observations provide evidence for the presence of X-ray line emission in the spectrum of Puppis A near .65 keV.

  15. Direct design of aspherical lenses for extended non-Lambertian sources in three-dimensional rotational geometry.

    PubMed

    Wu, Rengmao; Hua, Hong

    2016-01-25

    Illumination design used to redistribute the spatial energy distribution of light source is a key technique in lighting applications. However, there is still no effective illumination design method for extended sources, especially for extended non-Lambertian sources. What we present here is to our knowledge the first direct method for extended non-Lambertian sources in three-dimensional (3D) rotational geometry. In this method, both meridional rays and skew rays of the extended source are taken into account to tailor the lens profile in the meridional plane. A set of edge rays and interior rays emitted from the extended source which will take a given direction after the refraction of the aspherical lens are found by the Snell's law, and the output intensity at this direction is then calculated to be the integral of the luminance function of the outgoing rays at this direction. This direct method is effective for both extended non-Lambertian sources and extended Lambertian sources in 3D rotational symmetry, and can directly find a solution to the prescribed design problem without cumbersome iterative illuminance compensation. Two examples are presented to demonstrate the effectiveness of the proposed method in terms of performance and capacity for tackling complex designs. PMID:26832484

  16. Direct design of aspherical lenses for extended non-Lambertian sources in three-dimensional rotational geometry.

    PubMed

    Wu, Rengmao; Hua, Hong

    2016-01-25

    Illumination design used to redistribute the spatial energy distribution of light source is a key technique in lighting applications. However, there is still no effective illumination design method for extended sources, especially for extended non-Lambertian sources. What we present here is to our knowledge the first direct method for extended non-Lambertian sources in three-dimensional (3D) rotational geometry. In this method, both meridional rays and skew rays of the extended source are taken into account to tailor the lens profile in the meridional plane. A set of edge rays and interior rays emitted from the extended source which will take a given direction after the refraction of the aspherical lens are found by the Snell's law, and the output intensity at this direction is then calculated to be the integral of the luminance function of the outgoing rays at this direction. This direct method is effective for both extended non-Lambertian sources and extended Lambertian sources in 3D rotational symmetry, and can directly find a solution to the prescribed design problem without cumbersome iterative illuminance compensation. Two examples are presented to demonstrate the effectiveness of the proposed method in terms of performance and capacity for tackling complex designs.

  17. Spectral reconstruction of extended VHE γ-ray sources with the template background

    NASA Astrophysics Data System (ADS)

    Fernandes, Milton V.; Horns, Dieter; Raue, Martin

    2012-12-01

    Ground-based imaging air Cherenkov telescopes typically observe a solid angle of a few degrees in diameter. In many instances, the angular extent of γ-ray sources is comparable to the size of the field of view. For these objects, dedicated observations of source-free regions are required to estimate the background. The additional observation time and the non-simultaneous background estimate motivates alternative approaches to carry out imaging spectroscopy. In this contribution, we extend the so-called "template" background method that has been widely in use to generate sky maps to a general method to carry out imaging spectroscopy without the need of additional background observations. The method described in this contribution can be used for any imaging Cherenkov telescope data. Here, it is tested with published data taken with the H.E.S.S. array of Cherenkov telescopes and compared with the results of the standard analysis.

  18. Characteristics of large three-dimensional heaps of particles produced by ballistic deposition from extended sources

    NASA Astrophysics Data System (ADS)

    Topic, Nikola; Gallas, Jason A. C.; Pöschel, Thorsten

    2013-11-01

    This paper reports a detailed numerical investigation of the geometrical and structural properties of three-dimensional heaps of particles. Our goal is the characterization of very large heaps produced by ballistic deposition from extended circular dropping areas. First, we provide an in-depth study of the formation of monodisperse heaps of particles. We find very large heaps to contain three new geometrical characteristics: they may display two external angles of repose, one internal angle of repose, and four distinct packing fraction (density) regions. Such features are found to be directly connected with the size of the dropping zone. We derive a differential equation describing the boundary of an unexpected triangular packing fraction zone formed under the dropping area. We investigate the impact that noise during the deposition has on the final heap structure. In addition, we perform two complementary experiments designed to test the robustness of the novel features found. The first experiment considers changes due to polydispersity. The second checks what happens when letting the extended dropping zone to become a point-like source of particles, the more common type of source.

  19. SEDS: The Spitzer Extended Deep Survey. Survey Design, Photometry, and Deep IRAC Source Counts

    NASA Technical Reports Server (NTRS)

    Ashby, M. L. N.; Willner, S. P.; Fazio, G. G.; Huang, J.-S.; Arendt, A.; Barmby, P.; Barro, G; Bell, E. F.; Bouwens, R.; Cattaneo, A.; Croton, D.; Dave, R.; Dunlop, J. S.; Egami, E.; Faber, S.; Finlator, K.; Grogin, N. A.; Guhathakurta, P.; Hernquist, L.; Hora, J. L.; Illingworth, G.; Kashlinsky, A; Koekmoer, A. M.; Koo, D. C.; Moseley, H.

    2013-01-01

    The Spitzer Extended Deep Survey (SEDS) is a very deep infrared survey within five well-known extragalactic science fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the Hubble Deep Field North, and the Extended Groth Strip. SEDS covers a total area of 1.46 deg(exp 2) to a depth of 26 AB mag (3sigma) in both of the warm Infrared Array Camera (IRAC) bands at 3.6 and 4.5 micron. Because of its uniform depth of coverage in so many widely-separated fields, SEDS is subject to roughly 25% smaller errors due to cosmic variance than a single-field survey of the same size. SEDS was designed to detect and characterize galaxies from intermediate to high redshifts (z = 2-7) with a built-in means of assessing the impact of cosmic variance on the individual fields. Because the full SEDS depth was accumulated in at least three separate visits to each field, typically with six-month intervals between visits, SEDS also furnishes an opportunity to assess the infrared variability of faint objects. This paper describes the SEDS survey design, processing, and publicly-available data products. Deep IRAC counts for the more than 300,000 galaxies detected by SEDS are consistent with models based on known galaxy populations. Discrete IRAC sources contribute 5.6 +/- 1.0 and 4.4 +/- 0.8 nW / square m/sr at 3.6 and 4.5 micron to the diffuse cosmic infrared background (CIB). IRAC sources cannot contribute more than half of the total CIB flux estimated from DIRBE data. Barring an unexpected error in the DIRBE flux estimates, half the CIB flux must therefore come from a diffuse component.

  20. Extended soft x-ray source in Delphinus: H2027+19

    SciTech Connect

    Stern, R.A.; Charles, P.A.; Walker, B.C.; Nugent, J.J.; Garmire, G.P.

    1980-06-01

    We report the detection of an extended (approx.3/sup 0/) source of soft X-ray emission. H2027+19, observed with the HEAO 1 A-2 experiment. The object emits primarily in the 0.16--0.4 keV band, with a total flux in this band of approx.2 x 10/sup -11/ ergs cm/sup -2/ S/sup -1/. Although our data can be formally modeled with two discrete sources, a detailed analysis suggests that this alternative is not likely to be the case. We fine that both simple continuum and coronal plasma models provide good fits to the observed pulse-height spectrum. The source parameters are restricted to 10/sup 5.8/ source is an old supernova remnant or that it is a region of enhanced soft X-ray emission surrounding an H I cloud imbedded in a cornal plasma, as suggested by Hayakawa et al. for the Lupus Loop.

  1. Localization of extended brain sources from EEG/MEG: the ExSo-MUSIC approach.

    PubMed

    Birot, Gwénaël; Albera, Laurent; Wendling, Fabrice; Merlet, Isabelle

    2011-05-01

    We propose a new MUSIC-like method, called 2q-ExSo-MUSIC (q ≥ 1). This method is an extension of the 2q-MUSIC (q ≥ 1) approach for solving the EEG/MEG inverse problem, when spatially-extended neocortical sources ("ExSo") are considered. It introduces a novel ExSo-MUSIC principle. The novelty is two-fold: i) the parameterization of the spatial source distribution that leads to an appropriate metric in the context of distributed brain sources and ii) the introduction of an original, efficient and low-cost way of optimizing this metric. In 2q-ExSo-MUSIC, the possible use of higher order statistics (q ≥ 2) offers a better robustness with respect to Gaussian noise of unknown spatial coherence and modeling errors. As a result we reduced the penalizing effects of both the background cerebral activity that can be seen as a Gaussian and spatially correlated noise, and the modeling errors induced by the non-exact resolution of the forward problem. Computer results on simulated EEG signals obtained with physiologically-relevant models of both the sources and the volume conductor show a highly increased performance of our 2q-ExSo-MUSIC method as compared to the classical 2q-MUSIC algorithms.

  2. The G-HAT Search for Advanced Extraterrestrial Civilizations: The Reddest Extended WISE Sources

    NASA Astrophysics Data System (ADS)

    Maldonado, Jessica; Povich, Matthew S.; Wright, Jason; Griffith, Roger; Sigurdsson, Steinn; Mullan, Brendan L.

    2015-01-01

    Freeman Dyson (1960) theorized how to identify possible signatures of advanced extra-terrestrial civilizations by their waste heat, an inevitable byproduct of a civilization using a significant fraction of the luminosity from their host star. If a civilizations could tap the starlight throughout their host galaxy their waste heat would be easily detectable by recent infrared surveys. The Glimpsing Heat from Alien Technologies (G-HAT) pilot project aims to place limits on the existence of extraterrestrial civilizations at pan-galactic scales. We present results from the G-HAT cleaned catalog of 563 extremely red, extended high Galactic latitude (|b| ≥ 10) sources from the WISE All-Sky Catalog. Our catalog includes sources new to the scientific literature along with well-studied objects (e.g. starburst galaxies, AGN, and planetary nebulae) that exemplify extreme WISE colors. Objects of particular interest include a supergiant Be star (48 Librae) surrounded by a resolved, mid-infrared nebula, possibly indicating dust in the stellar wind ejecta, and a curious cluster of seven extremely red WISE sources (associated with IRAS 04287+6444) that have no optical counterparts.

  3. Confidence range estimate of extended source imagery acquisition algorithms via computer simulations. [in optical communication systems

    NASA Technical Reports Server (NTRS)

    Chen, CHIEN-C.; Hui, Elliot; Okamoto, Garret

    1992-01-01

    Spatial acquisition using the sun-lit Earth as a beacon source provides several advantages over active beacon-based systems for deep-space optical communication systems. However, since the angular extend of the Earth image is large compared to the laser beam divergence, the acquisition subsystem must be capable of resolving the image to derive the proper pointing orientation. The algorithms used must be capable of deducing the receiver location given the blurring introduced by the imaging optics and the large Earth albedo fluctuation. Furthermore, because of the complexity of modelling the Earth and the tracking algorithms, an accurate estimate of the algorithm accuracy can only be made via simulation using realistic Earth images. An image simulator was constructed for this purpose, and the results of the simulation runs are reported.

  4. X-ray imaging crystal spectrometer for extended X-ray sources

    DOEpatents

    Bitter, Manfred L.; Fraenkel, Ben; Gorman, James L.; Hill, Kenneth W.; Roquemore, A. Lane; Stodiek, Wolfgang; von Goeler, Schweickhard E.

    2001-01-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

  5. X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources

    SciTech Connect

    Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

    1999-05-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

  6. ON THE EVOLUTION OF THE CORES OF RADIO SOURCES AND THEIR EXTENDED RADIO EMISSION

    SciTech Connect

    Yuan Zunli; Wang Jiancheng

    2012-01-10

    The work in this paper aims at determining the evolution and possible co-evolution of radio-loud active galactic nuclei (AGNs) and their cores via their radio luminosity functions (i.e., total and core RLFs, respectively). Using a large combined sample of 1063 radio-loud AGNs selected at low radio frequency, we investigate the RLF at 408 MHz of steep-spectrum radio sources. Our results support a luminosity-dependent evolution. Using core flux density data of the complete sample 3CRR, we investigate the core RLF at 5.0 GHz. Based on the combined sample with incomplete core flux data, we also estimate the core RLF using a modified factor of completeness. Both results are consistent and show that the comoving number density of radio cores displays a persistent decline with redshift, implying a negative density evolution. We find that the core RLF is obviously different from the total RLF at the 408 MHz band which is mainly contributed by extended lobes, implying that the cores and extended lobes could not be co-evolving at radio emission.

  7. On the Evolution of the Cores of Radio Sources and Their Extended Radio Emission

    NASA Astrophysics Data System (ADS)

    Yuan, Zunli; Wang, Jiancheng

    2012-01-01

    The work in this paper aims at determining the evolution and possible co-evolution of radio-loud active galactic nuclei (AGNs) and their cores via their radio luminosity functions (i.e., total and core RLFs, respectively). Using a large combined sample of 1063 radio-loud AGNs selected at low radio frequency, we investigate the RLF at 408 MHz of steep-spectrum radio sources. Our results support a luminosity-dependent evolution. Using core flux density data of the complete sample 3CRR, we investigate the core RLF at 5.0 GHz. Based on the combined sample with incomplete core flux data, we also estimate the core RLF using a modified factor of completeness. Both results are consistent and show that the comoving number density of radio cores displays a persistent decline with redshift, implying a negative density evolution. We find that the core RLF is obviously different from the total RLF at the 408 MHz band which is mainly contributed by extended lobes, implying that the cores and extended lobes could not be co-evolving at radio emission.

  8. Crawling The Web for Libre: Selecting, Integrating, Extending and Releasing Open Source Software

    NASA Astrophysics Data System (ADS)

    Truslove, I.; Duerr, R. E.; Wilcox, H.; Savoie, M.; Lopez, L.; Brandt, M.

    2012-12-01

    Libre is a project developed by the National Snow and Ice Data Center (NSIDC). Libre is devoted to liberating science data from its traditional constraints of publication, location, and findability. Libre embraces and builds on the notion of making knowledge freely available, and both Creative Commons licensed content and Open Source Software are crucial building blocks for, as well as required deliverable outcomes of the project. One important aspect of the Libre project is to discover cryospheric data published on the internet without prior knowledge of the location or even existence of that data. Inspired by well-known search engines and their underlying web crawling technologies, Libre has explored tools and technologies required to build a search engine tailored to allow users to easily discover geospatial data related to the polar regions. After careful consideration, the Libre team decided to base its web crawling work on the Apache Nutch project (http://nutch.apache.org). Nutch is "an open source web-search software project" written in Java, with good documentation, a significant user base, and an active development community. Nutch was installed and configured to search for the types of data of interest, and the team created plugins to customize the default Nutch behavior to better find and categorize these data feeds. This presentation recounts the Libre team's experiences selecting, using, and extending Nutch, and working with the Nutch user and developer community. We will outline the technical and organizational challenges faced in order to release the project's software as Open Source, and detail the steps actually taken. We distill these experiences into a set of heuristics and recommendations for using, contributing to, and releasing Open Source Software.

  9. Extended culture of macrophages from different sources and maturation results in a common M2 phenotype.

    PubMed

    Chamberlain, Lisa M; Holt-Casper, Dolly; Gonzalez-Juarrero, Mercedes; Grainger, David W

    2015-09-01

    Inflammatory responses to biomaterials heavily influence the environment surrounding implanted devices, often producing foreign-body reactions. The macrophage is a key immunomodulatory cell type consistently associated with implanted biomaterials and routinely used in short-term in vitro cell studies of biomaterials aiming to reproduce host responses. Inconsistencies within these studies, including differently sourced cells, different durations of culture, and assessment of different activation markers, lead to many conflicting results in vitro that confound consistency and conclusions. We hypothesize that different experimentally popular monocyte-macrophage cell types have intrinsic in vitro culture-specific differences that yield conflicting results. Recent studies demonstrate changes in cultured macrophage cytokine expression over time, leading to the hypothesis that changes in macrophage phenotype also occur in response to extended culture. Here, macrophage cells of different transformed and primary-derived origins were cultured for 21 days on model polymer biomaterials. Cell type-based differences in morphology and cytokine/chemokine expression as well as changes in cell surface biomarkers associated with differentiation stage, activation state, and adhesion were compared. Results reflect consistent macrophage development toward an M2 phenotype via up-regulation of the macrophage mannose receptor for all cell types following 21-day extended culture. Significantly, implanted biomaterials experiencing the foreign-body response and encapsulation in vivo often elicit a shift toward an analogous M2 macrophage phenotype. In vitro "default" of macrophage cultures, regardless of lineage, to this M2 state in the presence of biomaterials at long culture periods is not recognized, but has important implications to in vitro modeling of in vivo host response.

  10. EXTENDED CULTURE OF MACROPHAGES FROM DIFFERENT SOURCES AND MATURATION RESULTS IN A COMMON M2 PHENOTYPE

    PubMed Central

    Chamberlain, Lisa M.; Holt-Casper, Dolly; Gonzalez-Juarrero, Mercedes; Grainger, David W.

    2015-01-01

    Inflammatory responses to biomaterials heavily influence the environment surrounding implanted devices, often producing foreign body reactions. The macrophage is a key immunomodulatory cell type consistently associated with implanted biomaterials and routinely employed in short term in vitro cell studies of biomaterials aiming to reproduce host responses. Inconsistencies within these studies, including differently sourced cells, different durations of culture, and assessment of different activation markers, lead to many conflicting results in vitro that confound consistency and conclusions. We hypothesize that different experimentally popular monocyte-macrophage cell types have intrinsic in vitro culture-specific differences that yield conflicting results. Recent studies demonstrate changes in cultured macrophage cytokine expression over time, leading to the hypothesis that changes in macrophage phenotype also occur in response to extended culture. Here, macrophage cells of different transformed and primary-derived origins were cultured for 21 days on model polymer biomaterials. Cell type-based differences in morphology and cytokine/chemokine expression as well as changes in cell surface biomarkers associated with differentiation stage, activation state, and adhesion were compared. Results reflect consistent macrophage development towards an M2 phenotype via up-regulation of the macrophage mannose receptor for all cell types following 21-day extended culture. Significantly, implanted biomaterials experiencing the foreign body response and encapsulation in vivo often elicit a shift towards an analogous M2 macrophage phenotype. In vitro “default” of macrophage cultures, regardless of lineage, to this M2 state in the presence of biomaterials at long culture periods is not recognized but has important implications to in vitro modeling of in vivo host response. PMID:25684281

  11. Extended-Boussinesq thermal-chemical convection with moving heat sources and variable viscosity

    NASA Astrophysics Data System (ADS)

    Hansen, U.; Yuen, D. A.

    2000-03-01

    We have studied with an aspect-ratio four box the thermal-chemical convective evolution with strongly temperature- and depth-dependent viscosity and moving heat sources within the extended-Boussinesq framework, in which both adiabatic and viscous heating are included and a depth-dependent thermal expansivity is assumed in the equation of state. Our focus is to show how this type of mantle evolution with an averaged Ra of 0(10 6) may develop with a linear chemical stratification and a uniformly hot mantle as an initial condition. The effects of extended-Boussinesq and depth-dependent thermal expansivity are to prevent the effective destruction of the chemical heterogeneities. Our results show that this initial condition would, after the age of the Earth, lead to a 'lava lamp' mode consisting of a thick chemically stratified and intensely internally heated layer with a thickness of around a quarter of the whole mantle thickness. However, in this isolated internally convecting layer, exceedingly high temperatures greater than 4500 K would be reached in the deep mantle. Plumes can be launched from the top of this thick denser layer. This 'lava lamp' stage would give way to the formation of denser hill-like structures at the core-mantle boundary. Then upwellings with deep lower mantle origins can be induced by the interaction of the downwellings with the D″ layer. Our simulations show the possibility for some long-range mass transfer interaction between these widely separated chemical hills promoted by the fast horizontal flow induced by the sinking currents along the low-viscosity zone due to temperature-dependent rheology at the core-mantle boundary.

  12. Flux-Calibrated Emission-Line Imaging of Extended Sources Using GTC/OSIRIS Tunable Filters

    NASA Astrophysics Data System (ADS)

    Mayya, Y. D.; Rosa González, D.; Vega, O.; Méndez-Abreu, J.; Terlevich, R.; Terlevich, E.; Bertone, E.; Rodríguez-Merino, L. H.; Muñoz-Tuñón, C.; Rodríguez-Espinosa, J. M.; Sánchez Almeida, J.; Aguerri, J. A. L.

    2012-08-01

    We investigate the utility of the tunable filters (TFs) for obtaining flux-calibrated emission-line maps of extended objects such as galactic nebulae and nearby galaxies using the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) at the 10.4-m Gran Telescopio Canarias (GTC). Despite the relatively large field of view (FoV) of OSIRIS (8' × 8'), the change in wavelength across the field (~80 Å) and the long tail of the TF spectral response function are hindrances for obtaining accurate flux-calibrated emission-line maps of extended sources. The purpose of this article is to demonstrate that emission-line maps useful for diagnostics of nebulae can be generated over the entire FoV of OSIRIS if we make use of theoretically well-understood characteristics of TFs. We have successfully generated the flux-calibrated images of the nearby large late-type spiral galaxy M101 in the emission lines of Hα, [N II]λ6583, [S II]λ6716 and [S II]λ6731. We find that the present uncertainty in setting the central wavelength of TFs (~1 Å) is the biggest source of error in the emission-line fluxes. By comparing the Hα fluxes of H II regions in our images with the fluxes derived from Hα images obtained using narrow-band filters, we estimate an error of ~11% in our fluxes. The flux-calibration of the images was carried out by fitting the Sloan Digital Sky Survey (SDSS) griz magnitudes of in-frame stars with the stellar spectra from the SDSS spectral database. This method resulted in an accuracy of 3% in flux-calibration of any narrow-band image, which is as good as, if not better than, what has been feasible using the observations of spectrophotometric standard stars. Thus time-consuming calibration images need not be taken. A user-friendly script under the IRAF environment was developed and is available on request. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the

  13. Two-dimensional extended fluid model for a dc glow discharge with nonlocal ionization source term

    NASA Astrophysics Data System (ADS)

    Rafatov, Ismail; Bogdanov, Eugeny; Kudryavtsev, Anatoliy

    2013-09-01

    Numerical techniques applied to the gas discharge plasma modelling are generally grouped into fluid and kinetic (particle) methods, and their combinations which lead to the hybrid models. Hybrid models usually employ Monte Carlo method to simulate fast electron dynamics, while slow plasma species are described as fluids. However, since fast electrons contribution to these models is limited to deriving the ionization rate distribution, their effect can be expressed by the analytical approximation of the ionization source function, and then integrating it into the fluid model. In the context of this approach, we incorporated effect of fast electrons into the ``extended fluid model'' of glow discharge, using two spatial dimensions. Slow electrons, ions and excited neutral species are described by the fluid plasma equations. Slow electron transport (diffusion and mobility) coefficients as well as electron induced reaction rates are determined from the solutions of the electron Boltzmann equation. The self-consistent electric field is calculated using the Poisson equation. We carried out test calculations for the discharge in argon gas. Comparison with the experimental data as well as with the hybrid model results exhibits good applicability of the proposed model. The work was supported by the joint research grant from the Scientific and Technical Research Council of Turkey (TUBITAK) 212T164 and Russian Foundation for Basic Research (RFBR).

  14. An extended source for CN jets in Comet P/Halley

    NASA Technical Reports Server (NTRS)

    Klavetter, James Jay; A'Hearn, Michael F.

    1994-01-01

    We examined radial intensity profiles of CN jets in comparison with the diffuse, isotropic component of the CN coma of Comet P/Halley. All images were bias-subtracted, flat-fielded, and continuum-subtracted. We calculated the diffuse profiles by finding the azimuthal mean of the coma least contaminated by jets yielding profiles similar to those of vectorial and Haser models of simple photodissociation. We found the jet profiles by calculating a mean around a Gaussian-fitted center in r-theta space. There is an unmistakable difference between the profiles of the CN jets and the profiles of the diffuse CN. Spatial derivatives of these profiles, corrected for geometrical expansion, show that the diffuse component is consistent with a simple photodissociation process, but the jet component is not. The peak production of the jet profile occurs 6000 km from the nucleus at a heliocentric distance of 1.4 AU. Modeling of both components of the coma indicate results that are consistent with the diffuse CN photochemically produced, but the CN jets need an additional extended source. We found that about one-half of the CN in the coma of Comet P/Halley originated from the jets, the rest from the diffuse component. These features, along with the width of the jet being approximately constant, are consistent with a CHON grain origin for the jets.

  15. Simulations of three-dimensional radiometric imaging of extended sources in a security screening portal

    NASA Astrophysics Data System (ADS)

    Salmon, Neil A.; Bowring, Nick

    2015-10-01

    This paper investigates by simulation the use of the three-dimensional aperture synthesis imaging technique to image three-dimensional extended sources. Software was written to access the three-dimensional information from computer graphics models in the formats of *.dxf and *.3ds and use these to generate synthetic cross-correlations, as if they would have been generated by an aperture synthesis antenna/receiver array measuring the radiometric emission from the three-dimensional object. A three-dimensional (near-field) aperture synthesis imaging algorithm generates [1] a voxel image of the three-dimensional object. Images created from a sphere indicate faithful reproduction about a single phase centre when the radius of the sphere is less than the Fresnel scale. However, for larger spheres, definition in the threedimensional imagery suffers and a phenomenon, referred to in this paper as Fresnel noise, appears in the image. Images of objects larger than the Fresnel scale can be created by having multiple smaller images, each having a size approximately of the Fresnel scale and centred on separate phase centres. Using the software to generate threedimensional imagery of a person, to demonstrate capabilities for portal security screening, indicates the technique works to first order. Improvements are needed in the software to improve the spatial sampling of the radiometric fields from the three-dimensional objects and implement a volumetric image mosaicking technique to remove the Fresnel noise.

  16. Complementary optimization method of freeform lens design for uniform illumination with extended light-emitting diode sources

    NASA Astrophysics Data System (ADS)

    Wang, Te-Yuan; Chen, Jin-Jia; Huang, Kuang-Lung; Wang, Chuen-Ching

    2015-09-01

    A freeform lens design method based on energy mapping and complementary optimization approaches is proposed to achieve uniform illumination with extended light-emitting diode (LED) sources. This method is primarily derived from a simple source-a target energy mapping approach, while a complementary illuminance on the target plane is introduced to optimize the primary axisymmetric lens so that the profile of the lens can be reformed to produce uniform illumination when applying an extended LED source. By using this optimization method, the illuminance uniformity and optical efficiency of the lens can be improved, respectively, from 0.56 to 0.85 and from 92.4% to 94.3% for an LED light source with chip diameter of 8.9 mm, while the aspect ratio of the lens clear aperture to the source diameter is only 3.8.

  17. General-Purpose Heat Source development: Extended series test program large fragment tests

    SciTech Connect

    Cull, T.A.

    1989-08-01

    General-Purpose Heat Source radioisotope thermoelectric generators (GPHS-RTGs) will provide electric power for the NASA Galileo and European Space Agency Ulysses missions. Each GPHS-RTG comprises two major components: GPHS modules, which provide thermal energy, and a thermoelectric converter, which converts the thermal energy into electric power. Each of the 18 GPHS modules in a GPHS-RTG contains four /sup 238/PuO/sub 2/-fueled capsules. LANL conducted a series of safety verification tests on the GPHS-RTG before the scheduled May 1986 launch of the Galileo spacecraft to assess the ability of the GPHS modules to contain the plutonia in potential accident environments. As a result of the Challenger 51-L accident in January 1986, NASA postponed the launch of Galileo; the launch vehicle was reconfigured and the spacecraft trajectory was modified. These actions prompted NASA to reevaluate potential mission accidents, and an extended series safety test program was initiated. The program included a series of large fragment tests that simulated the collision of solid rocket booster (SRB) fragments, generated in an SRB motor case rupture or resulting from a range safety officer SRB destruct action, with the GPHS-RTG. The tests indicated that fueled clads, inside a converter, will not breach or release fuel after a square (142 cm on a side) SRB fragment impacts flat-on at velocities up to 212 m/s, and that only the leading fueled capsules breach and release fuel after the square SRB fragment impacts the modules, inside the converter, edge-on at 95 m/s. 8 refs., 32 figs., 7 tabs.

  18. Extended X-Ray Jet in Nearby Galaxy Reveals Energy Source

    NASA Astrophysics Data System (ADS)

    1999-10-01

    gorgeous in the detail it reveals," she said. Dr. Allyn Tennnant of NASA's Marshall Space Flight Center agreed. "It's incredible, being able to see all that structure in the jet," he said. "We have one fine X-ray telescope." Indeed at a distance of eleven million light years from Earth, Centaurus A has long been a favorite target of astronomers because it is the nearest example of a class of galaxies called active galaxies. Active galaxies are noted for their explosive activity, which is presumed to be due to a supermassive black hole in their center. The energy output due to the huge central black hole can in many cases affect the appearance of the entire galaxy. The Chandra X-ray image of Cen A, made with the High Resolution Camera, shows a bright source in the nucleus of the galaxy at the location of the suspected supermassive black hole. The bright jet extending out from the nucleus to the upper left is due to explosive activity around the black hole which ejects matter at high speeds from the vicinity of the black hole. A "counter jet" extending to the lower right can also be seen. This jet is probably pointing away from us, which accounts for its faint appearance. One of the most intriguing features of supermassive black holes is that they do not suck up all the matter that falls within their sphere of influence. Some of the matter falls inexorably toward the black hole, and some explodes away from the black hole in high-energy jets that move at near the speed of light. The presence of bright X-ray jets in the Chandra image means that electric fields are continually accelerating electrons to extremely high energies over enormous distances. Exactly how this happens is a major puzzle that Chandra may help to solve. To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov Dr. Stephen Murray of the Harvard-Smithsonian Center for Astrophysics is the principal investigator for the High Resolution Camera. NASA

  19. Teaching Image Formation by Extended Light Sources: The Use of a Model Derived from the History of Science

    ERIC Educational Resources Information Center

    Dedes, Christos; Ravanis, Konstantinos

    2009-01-01

    This research, carried out in Greece on pupils aged 12-16, focuses on the transformation of their representations concerning light emission and image formation by extended light sources. The instructive process was carried out in two stages, each one having a different, distinct target set. During the first stage, the appropriate conflict…

  20. Experimental Study of The Degradation of Polymers. Application To The Origin of Extended Sources In Cometary Atmospheres.

    NASA Astrophysics Data System (ADS)

    Fray, N.; Cottin, H.; Gazeau, M. C.; Minard, R. D.; Raulin, F.; Benilan, Y.

    Some molecules or radicals observed in cometary atmospheres present so-called Sex- & cedil;tended sourcesT. It means that their distribution in comae cannot be explained by a direct sublimation from the nucleus, but rather by a production in the coma. The origin of those extended sources is still an unsolved question. Some large organic molecules, like HCN polymers or polyoxymethylene [formaldehyde polymers: (-CH2-O-)n], are sometime evoked as possible parents for the extended sources of CN and H2CO re- spectively. These polymers in solid state on cometary grains could release volatiles through thermal and photolytic degradation. We have developed an experimental pro- gram in order to study the chemical reactions of degradration of solid polymers by UV irradiation and heating. The production of resulting small gaseous molecules is studied through MS, GC and IR analyses and provide identification of the degradation products and the determination of the photodegradation quantum yields or the ther- modegradation kinetics. Those fundamental data are then included into a model of the outer coma in order to interpret observations. We will present our latest results on the degradation of HCN polymers and polyoxymethylene. They show that the degradation of organic polymers is a possible source of molecules and radicals which present an extended source.

  1. Detection of a new extended soft X-ray source H1538-32 - A possible old supernova remnant

    NASA Technical Reports Server (NTRS)

    Riegler, G. R.; Agrawal, P. C.; Gull, S. F.

    1980-01-01

    The discovery in the Lupus region of a new, extended soft X-ray source, H1538-32, is reported, having a distance of approximately 340 pc, and a luminosity of 1 to 2 x 10 to the 34th ergs/sec. The observed energy spectrum of the source is well fitted either by a thermal bremsstrahlung spectrum with Gaunt factor but without line emission, or by a coronal plasma model which includes the X-ray emission lines of various elements and the continuum as outlined by Raymond and Smith (1977). On the basis of the extended nature of the source and its thermal spectrum, it is suggested that H1538-32 may be an old supernova remnant.

  2. Production version of the extended NASA-Langley vortex lattice FORTRAN computer program. Volume 2: Source code

    NASA Technical Reports Server (NTRS)

    Herbert, H. E.; Lamar, J. E.

    1982-01-01

    The source code for the latest production version, MARK IV, of the NASA-Langley Vortex Lattice Computer Program is presented. All viable subcritical aerodynamic features of previous versions were retained. This version extends the previously documented program capabilities to four planforms, 400 panels, and enables the user to obtain vortex-flow aerodynamics on cambered planforms, flowfield properties off the configuration in attached flow, and planform longitudinal load distributions.

  3. Extending the path for efficient extreme ultraviolet sources for advanced nanolithography

    SciTech Connect

    Sizyuk, Tatyana; Hassanein, Ahmed

    2015-09-15

    Developing efficient light sources for extreme ultraviolet (EUV) lithography is one of the most important problems of high volume manufacturing (HVM) of the next generation computer chips. Critical components of this technology are continued to face challenges in the demanding performance for HVM. Current investigations of EUV and beyond EUV (BEUV) community are focused on the dual-pulse laser produced plasma (LPP) using droplets of mass-limited targets. Two main objectives as well as challenges in the optimization of these light sources are related to enhancement of the conversion efficiency (CE) of the source and increase components lifetime of the collector optical system. These require significant experimental and computer simulation efforts. These requirements call for fine detail analysis of various plasma physics processes involved in laser target interactions and their effects on source optimization. We continued to enhance our comprehensive HEIGHTS simulation package and upgrade our CMUXE laboratories to study and optimize the efficiency of LPP sources. Integrated modeling and experimental research were done to both benchmark simulation results and to make projections and realistic predictions of the development path for powerful EUVL devices for HVM requirements. We continued the detail analysis of dual-pulse laser systems using various laser wavelengths and delay times between the two pulses. We showed that the efficiency of EUV sources can be improved utilizing the higher harmonics of Nd:YAG laser for the prepulse and the first harmonics for the main pulse, while still having lower efficiency than the combination involving CO{sub 2} laser in the range of parameters studied in this case. The differences in optimization process as well as in the source characteristics for two combinations of laser wavelengths were analyzed based on details of atomic and hydrodynamics processes during the evolving plasma plumes.

  4. Analysis of XMM-Newton Data from Extended Sources and the Diffuse X-Ray Background

    NASA Technical Reports Server (NTRS)

    Snowden, Steven

    2011-01-01

    Reduction of X-ray data from extended objects and the diffuse background is a complicated process that requires attention to the details of the instrumental response as well as an understanding of the multiple background components. We present methods and software that we have developed to reduce data from XMM-Newton EPIC imaging observations for both the MOS and PN instruments. The software has now been included in the Science Analysis System (SAS) package available through the XMM-Newton Science Operations Center (SOC).

  5. Development and characterization of a high-reliability, extended-lifetime H- ion source

    NASA Astrophysics Data System (ADS)

    Becerra, Gabriel; Barrows, Preston; Sherman, Joseph

    2015-11-01

    Phoenix Nuclear Labs (PNL) has designed and constructed a long-lifetime, negative hydrogen (H-) ion source, in partnership with Fermilab for an ion beam injector servicing future Intensity Frontier particle accelerators. The specifications for the low-energy beam transport (LEBT) section are 5-10 mA of continuous H- ion current at 30 keV with <0.2 π-mm-mrad emittance. Existing ion sources at Fermilab rely on plasma-facing electrodes, limiting their lifetime to a few hundred hours, while requiring relatively high gas loads on downstream components. PNL's design features an electron cyclotron resonance (ECR) microwave plasma driver which has been extensively developed in positive ion source systems, having demonstrated 1000+ hours of operation and >99% continuous uptime at PNL. Positive ions and hyperthermal neutrals drift toward a low-work-function surface, where a fraction is converted into H- hydrogen ions, which are subsequently extracted into a low-energy beam using electrostatic lenses. A magnetic filter preferentially removes high-energy electrons emitted by the source plasma, in order to mitigate H- ion destruction via electron-impact detachment. The design of the source subsystems and preliminary diagnostic results will be presented.

  6. OpenMx: An Open Source Extended Structural Equation Modeling Framework

    ERIC Educational Resources Information Center

    Boker, Steven; Neale, Michael; Maes, Hermine; Wilde, Michael; Spiegel, Michael; Brick, Timothy; Spies, Jeffrey; Estabrook, Ryne; Kenny, Sarah; Bates, Timothy; Mehta, Paras; Fox, John

    2011-01-01

    OpenMx is free, full-featured, open source, structural equation modeling (SEM) software. OpenMx runs within the "R" statistical programming environment on Windows, Mac OS-X, and Linux computers. The rationale for developing OpenMx is discussed along with the philosophy behind the user interface. The OpenMx data structures are introduced--these…

  7. Atmospheric pressure ion lens extends the stable operational region of an electrospray ion source for capillary electrophoresis-mass spectrometry.

    PubMed

    Zhao, Shuai Sherry; Zhong, Xuefei; Chen, David D Y

    2012-04-01

    An atmospheric ion lens incorporated into an electrospray ion source for capillary electrophoresis-mass spectrometry (CE-MS) is found to extend the stable operational regions for both flow rates and electrospray ionization (ESI) voltages. The stable operating conditions for the ESI source with and without the ion lens were characterized. The results showed that the stable operation region was widest when the voltage difference between the sprayer and the ion lens ranges from 2.6 to 2.8 kV, and under these condition, the CE-MS interface can be adapted to a broader range of electroosmotic and modifier flow rates. Modeling of the electric field in the electrospray ion source with the ion lens suggests that the extension of the stable region is attributed to the flatter equipotential surfaces around the sprayer tip and higher electric field strengths in the rest of the interface region. PMID:22589113

  8. Fast and robust technique for design of axisymmetric TIR optics in case of an extended light source

    NASA Astrophysics Data System (ADS)

    Moiseev, Mikhail A.; Doskolovich, Leonid L.; Borisova, Kseniya V.; Byzov, Egor V.

    2013-08-01

    We propose a new optimization method for computation of axisymmetric total internal reflection (TIR) optics for light-emitting diodes (LEDs). The method is designed for the general case of an extended light source, and is based on the analytical computation of an initial TIR profile for a point light source and its subsequent optimization. The distinctive feature of the proposed method is low computation time, which is a result of using in the optimization process of the adapted ray-tracing technique, based on the representation of optical surfaces by a set of truncated cones. The TIR optical element, generating a uniformly illuminated circular area with an angular size of 60°, is computed for the Lambert light source with a size of 1 × 1 mm2. The results of simulations prove the high performance of the proposed technique.

  9. ANALYTICAL COMPUTATION OF THE LYOT CORONAGRAPH RESPONSE TO AN EXTENDED SOURCE

    SciTech Connect

    Ferrari, Andre; Aime, Claude

    2010-01-01

    This paper gives analytical expressions of the intensity in a Lyot coronagraph when the object is a resolved uniform disk. Intensities are given inside the Lyot stop and in the final plane. The derivation relies on the decomposition of the impinging waves on Zernike functions which allows the computation of the expansion of the intensities on infinite series. The expression in the final plane assumes that the sizes of the Lyot stop and the pupil are the same. An analysis of the truncation error is provided. These expressions are validated by computer simulations which makes it possible to recover known results such as the so-called diffraction ring observed by solar astronomers inside the Lyot stop. These analytical results and simulations bring deeper insight into the understanding of a Lyot coronagraph, for example, the fact that although the geometrical image of the source is behind the mask, a ghost image of the source can still be observed in the final plane.

  10. THE EXTENDED He IIλ4686-EMITTING REGION IN IZw 18 UNVEILED: CLUES FOR PECULIAR IONIZING SOURCES

    SciTech Connect

    Kehrig, C.; Vílchez, J. M.; Pérez-Montero, E.; Iglesias-Páramo, J.; Bayo, F. M.; Kunth, D.; Durret, F.

    2015-03-10

    New integral field spectroscopy has been obtained for IZw 18, the nearby lowest-metallicity galaxy considered to be our best local analog of systems forming at high redshift (z). Here we report the spatially resolved spectral map of the nebular He ii λ4686 emission in IZw 18, from which we derived for the first time its total He ii-ionizing flux. Nebular He ii emission implies the existence of a hard radiation field. He ii-emitters are observed to be more frequent among high-z galaxies than for local objects. Therefore, investigating the He ii-ionizing source(s) in IZw 18 may reveal the ionization processes at high z. He ii emission in star-forming galaxies has been suggested to be mainly associated with Wolf–Rayet stars (WRs), but WRs cannot satisfactorily explain the He ii-ionization at all times, particularly at the lowest metallicities. Shocks from supernova remnants, or X-ray binaries, have been proposed as additional potential sources of He ii-ionizing photons. Our data indicate that conventional He ii-ionizing sources (WRs, shocks, X-ray binaries) are not sufficient to explain the observed nebular He iiλ4686 emission in IZw 18. We find that the He ii-ionizing radiation expected from models for either low-metallicity super-massive O stars or rotating metal-free stars could account for the He ii-ionization budget measured, while only the latter models could explain the highest values of He iiλ4686/Hβ observed. The presence of such peculiar stars in IZw 18 is suggestive and further investigation in this regard is needed. This letter highlights that some of the clues of the early universe can be found here in our cosmic backyard.

  11. Extended Source Gamma-Ray Emission from WIMP Annihilation in the Sagittarius Dwarf Elliptical Galaxy (SULI paper)

    SciTech Connect

    Vasu-Devan, Vidya; /Columbia U. /SLAC

    2006-01-04

    The proximity of the dark matter dominated Sagittarius Dwarf Elliptical Galaxy (position (l,b) = 5.6{sup o}, -14{sup o}) allows it to act as an ideal laboratory for the exploration of extended gamma-ray emission from Weakly Interacting Massive Particle (WIMP) annihilation processes in a dark matter-dominated system. Since the matter in our universe is predominantly dark, exploring such processes as WIMP annihilation will lead to a better understanding of cosmology. In order to study this gamma-ray emission, a model for the diffuse background gamma-radiation in the dwarf galaxy's region is extracted from the Energetic Gamma Ray Experiment Telescope (EGRET) data. After validating this model and comparing it to the EGRET diffuse model, the background model is added to effective bleeding-contamination from external point sources and multiple models for the signal-above-background emission. Various models of this emission are tested: (a) no source located in region, (b) unidentified point source 3EG J1847-3219 from the Third EGRET Catalog responsible for the emission and (c) extended emission resulting from WIMP annihilation responsible for the signal above background. These models are created through the employment of Monte Carlo simulation methods, utilizing the response functions of the EGRET instrument to simulate the point spread function, energy dispersion and effects of variable effective area depending on angle of incidence. Energy spectra for point sources are generated from the best predictions of spectral indices listed in the Third EGRET Catalog and the spectrum for the extended dark matter source is generated from Pythia high energy annihilation simulations. Hypothesis testing is conducted to assess the goodness-of-fit of these models to the data taken by EGRET. Additionally, we hope to expand our analysis by employing the response functions of the imminent Gamma Ray Large Area Space Telescope (GLAST) to our models. This extension should highlight the

  12. High flux, narrow bandwidth compton light sources via extended laser-electron interactions

    DOEpatents

    Barty, V P

    2015-01-13

    New configurations of lasers and electron beams efficiently and robustly produce high flux beams of bright, tunable, polarized quasi-monoenergetic x-rays and gamma-rays via laser-Compton scattering. Specifically, the use of long-duration, pulsed lasers and closely-spaced, low-charge and low emittance bunches of electron beams increase the spectral flux of the Compton-scattered x-rays and gamma rays, increase efficiency of the laser-electron interaction and significantly reduce the overall complexity of Compton based light sources.

  13. A Suborbital Payload for Soft X-ray Spectroscopy of Extended Sources

    NASA Astrophysics Data System (ADS)

    Oakley, Phillip Henry Howard

    This thesis details the intent, design and results of an X-ray suborbital rocket payload whose scientific target was the Cygnus Loop Supernova Remnant. The payload consists of wire grid collimators, off-plane gratings arrays and gaseous electron multiplier (GEM) detectors. The system was designed for measurements in the 17-107 Å bandpass with a resolution up to ∼ 60 (λ=Δλ). This instrument was christened the Extended X-ray Off-plane Spectrometer (EXOS) and was launched on a Terrier-Black Brant rocket on November 13th, 2009 from White Sands Missile Range and obtained 340 seconds of useable scientific data. The emission is dominated by O VII and O VIII, including the He-like O VII triplet at ∼22 Å. Another feature at ∼45 Å is composed primarily of Si XI and Si XII. The best-fit model to this spectrum is an equilibrium plasma model at a temperature of log(T) = 6.4 (0.23 keV).

  14. Mars Science Laboratory with Power Source and Extended Arm, Artist's Concept

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Science Laboratory, a mobile robot for investigating Mars' past or present ability to sustain microbial life, is in development for a launch opportunity in 2009. This picture is an artist's concept portraying what the advanced rover would look like in Martian terrain, from a side aft angle.

    The arm extending from the front of the rover is designed both to position some of the rover's instruments onto selected rocks or soil targets and also to collect samples for analysis by other instruments. Near the base of the arm is a sample preparation and handling system designed to grind samples, such as rock cores or small pebbles, and distribute the material to analytical instruments.

    The mast, rising to about 2.1 meters (6.9 feet) above ground level, supports two remote-sensing instruments: the Mast Camera for stereo color viewing of surrounding terrain and material collected by the arm, and the ChemCam for analyzing the types of atoms in material that laser pulses have vaporized from rocks or soil targets up to about 9 meters (30 feet) away.

  15. Computation of the diffraction from complex illumination sources in extended regions of space.

    PubMed

    Karagounis, G; De Zutter, D; Vande Ginste, D

    2013-12-16

    In this paper, a two-dimensional high-frequency formalism is presented which describes the diffraction of arbitrary wavefronts incident on edges of an otherwise smooth surface. The diffracted field in all points of a predefined region of interest is expressed in terms of the generalized Huygens representation of the incident field and a limited set of translation coefficients that take into account the arbitrary nature of the incident wavefront and its diffraction. The method is based on the Uniform Theory of Diffraction (UTD) and can therefore be utilized for every canonical problem for which the UTD diffraction coefficient is known. Moreover, the proposed technique is easy to implement as only standard Fast Fourier Transform (FFT) routines are required. The technique's validity is confirmed both theoretically and numerically. It is shown that for fields emitted by a discrete line source and diffracted by a perfectly conducting wedge, the method is in excellent agreement with the analytic solution over the entire simulation domain, including regions near shadow and reflection boundaries. As an application example, the diffraction in the presence of a perfectly conducting wedge illuminated by a complex light source is analyzed, demonstrating the appositeness of the method. PMID:24514616

  16. Preliminary design and optimization of a G-band extended interaction oscillator based on a pseudospark-sourced electron beam

    SciTech Connect

    Yin, Y. E-mail: yinyong@uestc.edu.cn; He, W.; Zhang, L.; Yin, H.; Cross, A. W.

    2015-07-15

    The design and simulation of a G-band extended interaction oscillator (EIO) driven by a pseudospark-sourced electron beam is presented. The characteristic of the EIO and the pseudospark-based electron beam were studied to enhance the performance of the newly proposed device. The beam-wave interaction of the EIO can be optimized by choosing a suitable pseudospark discharging voltage and by widening the operating voltage region of the EIO circuit. Simulation results show that a peak power of over 240 W can be achieved at G-band using a pseudospark discharge voltage of 41 kV.

  17. 0.6 GHz mapping of extended radio galaxies. II - Edge-darkened double sources

    NASA Astrophysics Data System (ADS)

    Jaegers, W. J.

    1987-10-01

    Radio observations made with the Westerbork telescope at 0.6 GHz are presented for 8 edge-darkened double sources: NGC 315, NGC 326, 3C 31, 3C 130, B 0915+320, HB 13, NGC 6251 and 3C 449. Previously observed Westerbork data at 1.4 GHz are convolved for comparison with the 0.6 GHz observational data. Besides maps of the total intensity and linear polarization structure, the distributions of the spectral index, the depolarization and the rotation of the polarization position angle between 0.6 GHz and 1.4 GHz have been derived. Integrated values for the total intensity and the polarization are also given.

  18. Extended Tonks-Langmuir-type model with non-Boltzmann-distributed electrons and cold ion sources

    NASA Astrophysics Data System (ADS)

    Kamran, M.; Kuhn, S.; Tskhakaya, D. D.; Khan, M.; Khan

    2013-04-01

    A general formalism for calculating the potential distribution Φ(z) in the quasineutral region of a new class of plane Tonks-Langmuir (TL)-type bounded-plasma-system (BPS) models differing from the well-known `classical' TL model (Tonks, L. and Langmuir, I. 1929 A general theory of the plasma of an arc. Phys. Rev. 34, 876) by allowing for arbitrary (but still cold) ion sources and arbitrary electron distributions is developed. With individual particles usually undergoing microscopic collision/sink/source (CSS) events, extensive use is made here of the basic kinetic-theory concept of `CSS-free trajectories' (i.e., the characteristics of the kinetic equation). Two types of electron populations, occupying the `type-t' and `type-p' domains of electron phase space, are distinguished. By definition, the type-t and type-p domains are made up of phase points lying on type-t (`trapped') CSS-free trajectories (not intersecting the walls and closing on themselves) and type-p (`passing') ones (starting at one of the walls and ending at the other). This work being the first step, it is assumed that ɛ ≡ λ D /l -> 0+ (where λ D and l are a typical Debye length and a typical ionization length respectively) so that the system exhibits a finite quasineutral `plasma' region and two infinitesimally thin `sheath' regions associated with the `sheath-edge singularities' | dΦ/dz| z->+/-zs -> ∞. The potential in the plasma region is required to satisfy a plasma equation (quasineutrality condition) of the form n i {Φ} = n e (Φ), where the electron density n e (Φ) is given and the ion density n i {Φ} is expressed in terms of trajectory integrals of the ion kinetic equation, with the ions produced by electron-impact ionization of cold neutrals. While previous TL-type models were characterized by electrons diffusing under the influence of frequent collisions with the neutral background particles and approximated by Maxwellian (Riemann, K.-U. 2006 Plasma-sheath transition in the

  19. Searches for extended and point-like neutrino sources with four years of IceCube data

    SciTech Connect

    Aartsen, M. G.; Ackermann, M.; Berghaus, P.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Arguelles, C.; BenZvi, S.; Ahrens, M.; Altmann, D.; Anderson, T.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Beatty, J. J.; Tjus, J. Becker; Becker, K.-H.; Berley, D.; Collaboration: IceCube Collaboration; and others

    2014-12-01

    We present results on searches for point-like sources of neutrinos using four years of IceCube data, including the first year of data from the completed 86 string detector. The total livetime of the combined data set is 1373 days. For an E {sup –2} spectrum, the observed 90% C.L. flux upper limits are ∼10{sup –12} TeV{sup –1} cm{sup –2} s{sup –1} for energies between 1 TeV and 1 PeV in the northern sky and ∼10{sup –11} TeV{sup –1} cm{sup –2} s{sup –1} for energies between 100 TeV and 100 PeV in the southern sky. This represents a 40% improvement compared to previous publications, resulting from both the additional year of data and the introduction of improved reconstructions. In addition, we present the first results from an all-sky search for extended sources of neutrinos. We update the results of searches for neutrino emission from stacked catalogs of sources and test five new catalogs; two of Galactic supernova remnants and three of active galactic nuclei. In all cases, the data are compatible with the background-only hypothesis, and upper limits on the flux of muon neutrinos are reported for the sources considered.

  20. Enhancing sensitivity of high resolution optical coherence tomography using an optional spectrally encoded extended source (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yu, Xiaojun; Liu, Xinyu; Chen, Si; Wang, Xianghong; Liu, Linbo

    2016-03-01

    High-resolution optical coherence tomography (OCT) is of critical importance to disease diagnosis because it is capable of providing detailed microstructural information of the biological tissues. However, a compromise usually has to be made between its spatial resolutions and sensitivity due to the suboptimal spectral response of the system components, such as the linear camera, the dispersion grating, and the focusing lenses, etc. In this study, we demonstrate an OCT system that achieves both high spatial resolutions and enhanced sensitivity through utilizing a spectrally encoded source. The system achieves a lateral resolution of 3.1 μm and an axial resolution of 2.3 μm in air; when with a simple dispersive prism placed in the infinity space of the sample arm optics, the illumination beam on the sample is transformed into a line source with a visual angle of 10.3 mrad. Such an extended source technique allows a ~4 times larger maximum permissible exposure (MPE) than its point source counterpart, which thus improves the system sensitivity by ~6dB. In addition, the dispersive prism can be conveniently switched to a reflector. Such flexibility helps increase the penetration depth of the system without increasing the complexity of the current point source devices. We conducted experiments to characterize the system's imaging capability using the human fingertip in vivo and the swine eye optic never disc ex vivo. The higher penetration depth of such a system over the conventional point source OCT system is also demonstrated in these two tissues.

  1. Multiwavelength study of the northeastern outskirts of the extended TeV source HESS J1809–193

    SciTech Connect

    Rangelov, Blagoy; Kargaltsev, Oleg; Hare, Jeremy; Volkov, Igor; Posselt, Bettina; Pavlov, George G.

    2014-11-20

    HESS J1809–193 is an extended TeV γ-ray source in the Galactic plane. Multiwavelength observations of the HESS J1809–193 field reveal a complex picture. We present results from three Chandra X-Ray Observatory and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our analysis also includes GeV γ-ray and radio data. One of the X-ray sources in the field is the X-ray binary XTE J1810-189, for which we present the outburst history from multiple observatories and confirm that XTE J1810-189 is a strongly variable type I X-ray burster, which can hardly produce TeV emission. We investigate whether there is any connection between the possible TeV extension of HESS J1809–193 and the sources seen at lower energies. We find that another X-ray binary candidate, Suzaku J1811-1900, and a radio supernova remnant, SNR G11.4–0.1, can hardly be responsible for the putative TeV emission. Our multiwavelength classification of fainter X-ray point sources also does not produce a plausible candidate. We conclude that the northeast extension of HESS J1809–193, if confirmed by deeper observations, can be considered a dark accelerator—a TeV source without a visible counterpart at lower energies.

  2. Emergence of ciprofloxacin-resistant extended-spectrum β-lactamase-producing enteric bacteria in hospital wastewater and clinical sources.

    PubMed

    Maheshwari, Meenu; Yaser, Nawar Hadi; Naz, Suraiya; Fatima, Mansha; Ahmad, Iqbal

    2016-06-01

    This study aimed to evaluate the incidence of ciprofloxacin-resistant extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and clinical sources. Enteric bacteria, mainly Escherichia coli, were isolated from clinical sources (urinary tract and gastrointestinal tract infections; 80 isolates) and hospital wastewater (103 isolates). The antibiotic resistance profile and ESBL production of the isolates were investigated by disc diffusion assay and combined disc diffusion test, respectively. Plasmid profiling was performed by agarose gel electrophoresis, and elimination of resistance markers was performed by a plasmid curing experiment. Antibiotic susceptibility testing revealed a high incidence of β-lactam resistance, being highest to ampicillin (88.0%) followed by amoxicillin, ceftriaxone, cefpodoxime, cefotaxime, aztreonam, cefepime and ceftazidime. Among the non-β-lactam antibiotics, the highest resistance was recorded to nalidixic acid (85.7%). Moreover, 50.8% of enteric bacteria showed resistance to ciprofloxacin. Among 183 total enteric bacteria, 150 (82.0%) exhibited multidrug resistance. ESBL production was detected in 78 isolates (42.6%). A significantly higher incidence of ciprofloxacin resistance was observed among ESBL-producing enteric bacteria both in clinical (P=0.0015) and environmental isolates (P=0.012), clearly demonstrating a close association between ESBL production and ciprofloxacin resistance. Plasmid profiling of selected ESBL-positive strains indicated the presence of one or more plasmids of varying sizes. Plasmid curing resulted in loss of ciprofloxacin and cefotaxime resistance markers simultaneously from selected ESBL-positive isolates, indicating the close relationship of these markers. This study revealed a common occurrence of ciprofloxacin-resistant ESBL-producing enteric bacteria both in hospital wastewater and clinical sources, indicating a potential public health threat.

  3. Teaching Image Formation by Extended Light Sources: The Use of a Model Derived from the History of Science

    NASA Astrophysics Data System (ADS)

    Dedes, Christos; Ravanis, Konstantinos

    2009-01-01

    This research, carried out in Greece on pupils aged 12-16, focuses on the transformation of their representations concerning light emission and image formation by extended light sources. The instructive process was carried out in two stages, each one having a different, distinct target set. During the first stage, the appropriate conflict conditions were created by contrasting the subjects’ predictions with the results of experimental situations inspired by the History of Science, with a view to destabilizing the pupils’ alternative representations. During the second stage, the experimental teaching intervention was carried out; it was based on the geometrical optics model and its parameters were derived from Kepler’s relevant historic experiment. For the duration of this process and within the framework of didactical interactions, an effort was made to reorganize initial limited representations and restructure them at the level of the accepted scientific model. The effectiveness of the intervention was evaluated two weeks later, using experimental tasks which had the same cognitive yet different empirical content with respect to the tasks conducted during the intervention. The results of the study showed that the majority of the subjects accepted the model of geometrical optics, that is, the pupils were able to correctly predict and adequately justify the experimental results based on the principle of punctiform light emission. Educational and research implications are discussed.

  4. CLASH: Extending galaxy strong lensing to small physical scales with distant sources highly magnified by galaxy cluster members

    SciTech Connect

    Grillo, C.; Christensen, L.; Gobat, R.; Balestra, I.; Nonino, M.; Biviano, A.; Mercurio, A.; Rosati, P.; Vanzella, E.; Graves, G.; Lemze, D.; Ford, H.; Bartelmann, M.; Benitez, N.; Bradley, L.; Coe, D.; Broadhurst, T.; Donahue, M.; and others

    2014-05-01

    We present a complex strong lensing system in which a double source is imaged five times by two early-type galaxies. We take advantage in this target of the extraordinary multi-band photometric data set obtained as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) program, complemented by the spectroscopic measurements of the VLT/VIMOS and FORS2 follow-up campaign. We use a photometric redshift value of 3.7 for the source and confirm spectroscopically the membership of the two lenses to the galaxy cluster MACS J1206.2–0847 at redshift 0.44. We exploit the excellent angular resolution of the HST/ACS images to model the two lenses in terms of singular isothermal sphere profiles and derive robust effective velocity dispersion values of 97 ± 3 and 240 ± 6 km s{sup –1}. Interestingly, the total mass distribution of the cluster is also well characterized by using only the local information contained in this lensing system, which is located at a projected distance of more than 300 kpc from the cluster luminosity center. According to our best-fitting lensing and composite stellar population models, the source is magnified by a total factor of 50 and has a luminous mass of approximately (1.0 ± 0.5) × 10{sup 9} M {sub ☉} (assuming a Salpeter stellar initial mass function). By combining the total and luminous mass estimates of the two lenses, we measure luminous over total mass fractions projected within the effective radii of 0.51 ± 0.21 and 0.80 ± 0.32. Remarkably, with these lenses we can extend the analysis of the mass properties of lens early-type galaxies by factors that are approximately two and three times smaller than previously done with regard to, respectively, velocity dispersion and luminous mass. The comparison of the total and luminous quantities of our lenses with those of astrophysical objects with different physical scales, like massive early-type galaxies and dwarf spheroidals, reveals the potential of studies of this kind for

  5. Improved biological phosphorus removal performance driven by the aerobic/extended-idle regime with propionate as the sole carbon source.

    PubMed

    Wang, Dongbo; Li, Xiaoming; Yang, Qi; Zheng, Wei; Wu, Yan; Zeng, Tianjing; Zeng, Guangming

    2012-08-01

    Our previous studies proved that biological phosphorus removal (BPR) could be achieved in an aerobic/extended-idle (AEI) process employing two typical substrates of glucose and acetate as the carbon sources. This paper further evaluated the feasibility of another important substrate, propionate, serving as the carbon source for BPR in the AEI process, and compared the BPR performance between the AEI and anaerobic/oxic (A/O) processes. Two sequencing batch reactors (SBRs) were operated, respectively, as the AEI and A/O regimes for BPR using propionate as the sole substrate. The results showed that the AEI-reactor removed 2.98 ± 0.04-4.06 ± 0.06 mg of phosphorus per g of total suspended solids during the course of the steady operational trial, and the phosphorus content of the dried sludge was reached 8.0 ± 0.4% after 56-day operation, demonstrating the good performance of phosphorus removal. Then, the efficiencies of BPR and the transformations of the intracellular storages were compared between two SBRs. It was observed that the phosphorus removal efficiency was maintained around 95% in the AEI-reactor, and about 83% in the A/O-reactor, although the latter showed much greater transformations of both polyhydroxyalkanoates and glycogen. The facts clearly showed that BPR could be enhanced by the AEI regime using propionate as the carbon source. Finally, the mechanisms for the propionate fed AEI-reactor improving BPR were investigated. It was found that the sludge cultured by the AEI regime had more polyphosphate containing cells than that by the A/O regime. Further investigation revealed that the residual nitrate generated in the last aerobic period was readily deteriorated BPR in the A/O-SBR, but a slight deterioration was observed in the AEI-SBR. Moreover, the lower glycogen transformation measured in the AEI-SBR indicated that the biomass cultured by the AEI regime contained less glycogen accumulating organisms activities than that by the A/O regime.

  6. THE STRUCTURE OF 2MASS GALAXY CLUSTERS

    SciTech Connect

    Blackburne, Jeffrey A.; Kochanek, Christopher S.

    2012-01-01

    We use a sample of galaxies from the Two Micron All Sky Survey Extended Source Catalog to refine a matched filter method of finding galaxy clusters that takes into account each galaxy's position, magnitude, and redshift if available. The matched filter postulates a radial density profile, luminosity function, and line-of-sight velocity distribution for cluster galaxies. We use this method to search for clusters in the galaxy catalog, which is complete to an extinction-corrected K-band magnitude of 13.25 and has spectroscopic redshifts for roughly 40% of the galaxies, including nearly all brighter than K = 11.25. We then use a stacking analysis to determine the average luminosity function, radial distribution, and velocity distribution of cluster galaxies in several richness classes, and use the results to update the parameters of the matched filter before repeating the cluster search. We also investigate the correlations between a cluster's richness and its velocity dispersion and core radius using these relations to refine priors that are applied during the cluster search process. After the second cluster search iteration, we repeat the stacking analysis. We find a cluster galaxy luminosity function that fits a Schechter form, with parameters M{sub K*} - 5log h = -23.64 {+-} 0.04 and {alpha} = -1.07 {+-} 0.03. We can achieve a slightly better fit to our luminosity function by adding a Gaussian component on the bright end to represent the brightest cluster galaxy population. The radial number density profile of galaxies closely matches a projected Navarro-Frenk-White profile at intermediate radii, with deviations at small radii due to well-known cluster centering issues and outside the virial radius due to correlated structure. The velocity distributions are Gaussian in shape, with velocity dispersions that correlate strongly with richness.

  7. New extended GeV sources in the Galactic plane found in a search of the Pass 8 data from Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Grondin, Marie-Helene; Cohen, Jamie; Hays, Elizabeth; Lemoine-Goumard, Marianne

    2016-06-01

    Spatially resolving pulsar wind nebulae (PWNe) and supernova remnants (SNRs) at GeV energies enables accurate representation of spectra, aids identification of multiwavelength counterparts, and probes possible substructure within the gamma-ray sources. Using 6 years of Fermi-LAT Pass 8 data above 10 GeV, we searched for spatially extended sources near the Galactic plane. The improved angular resolution and photon acceptance of the Pass 8 event reconstruction significantly aids in characterizing source extension and assessing spectral and morphological properties, a key consideration for studies of PWNe and SNRs in the gamma-ray band. Selecting photons above 10 GeV strikes a balance between keeping photon statistics high and diffuse gamma-ray emission low, and also carries the benefit of a near constancy with energy of the point spread function of the LAT. More than 30 significantly extended sources are detected, many of which are resolved at GeV energies for the first time.

  8. New Extended GeV Sources in the Galactic Plane Found in a Search of the Pass 8 Data from Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Hays, Elizabeth A.; Cohen, Jamie; Grondin, Marie-Hélène; Lemoine-Goumard, Marianne; Fermi LAT Collaboration

    2016-01-01

    Spatially resolving pulsar wind nebulae (PWNe) and supernova remnants (SNRs) at GeV energies enables accurate representation of spectra, aids identification of multiwavelength counterparts, and probes possible substructure within the gamma-ray sources. Using 6 years of Fermi-LAT Pass 8 data above 10 GeV, we searched for spatially extended sources near the Galactic plane. The improved angular resolution and photon acceptance of the Pass 8 event reconstruction significantly aids in characterizing source extension and assessing spectral and morphological properties, a key consideration for studies of PWNe and SNRs in the gamma-ray band. Selecting photons above 10 GeV strikes a balance between keeping photon statistics high and diffuse gamma-ray emission low, and also carries benefits of a near constancy with energy of the point spread function of the LAT. More than 30 significantly extended sources are detected, many of which are resolved at GeV energies for the first time.

  9. IDENTIFICATION OF A WIDE, LOW-MASS MULTIPLE SYSTEM CONTAINING THE BROWN DWARF 2MASS J0850359+105716

    SciTech Connect

    Faherty, Jacqueline K.; Burgasser, Adam J.; Bochanski, John J.; Looper, Dagny L.; West, Andrew A.; Van der Bliek, Nicole S.

    2011-03-15

    We report our discovery of NLTT 20346 as an M5+M6 companion system to the tight binary (or triple) L dwarf 2MASS J0850359+105716. This nearby ({approx}31 pc), widely separated ({approx}7700 AU) quadruple system was identified through a cross-match of proper motion catalogs. Follow-up imaging and spectroscopy of NLTT 20346 revealed it to be a magnetically active M5+M6 binary with components separated by {approx}2'' (50-80 AU). Optical spectroscopy of the components shows only moderate H{alpha} emission corresponding to a statistical age of {approx}5-7 Gyr for both M dwarfs. However, NLTT 20346 is associated with the XMM-Newton source J085018.9+105644, and based on X-ray activity the age of NLTT 20346 is between 250 and 450 Myr. Strong Li absorption in the optical spectrum of 2MASS J0850+1057 indicates an upper age limit of 0.8-1.5 Gyr, favoring the younger age for the primary. Using evolutionary models in combination with an adopted system age of 0.25-1.5 Gyr indicates a total mass for 2MASS J0850+1057 of 0.07 {+-} 0.02 M{sub sun}, if it is a binary. NLTT 20346/2MASS J0850+1057 joins a growing list of hierarchical systems containing brown dwarf binaries and is among the lowest binding energy associations found in the field. Formation simulations via gravitational fragmentation of massive extended disks have successfully produced a specific analog to this system.

  10. The FIRST-2MASS Red Quasar Survey

    SciTech Connect

    Glikman, E; Helfand, D J; White, R L; Becker, R H; Gregg, M D; Lacy, M

    2007-06-28

    Combining radio observations with optical and infrared color selection--demonstrated in our pilot study to be an efficient selection algorithm for finding red quasars--we have obtained optical and infrared spectroscopy for 120 objects in a complete sample of 156 candidates from a sky area of 2716 square degrees. Consistent with our initial results, we find our selection criteria--J-K > 1.7,R-K > 4.0--yield a {approx} 50% success rate for discovering quasars substantially redder than those found in optical surveys. Comparison with UVX- and optical color-selected samples shows that {approx}> 10% of the quasars are missed in a magnitude-limited survey. Simultaneous two-frequency radio observations for part of the sample indicate that a synchrotron continuum component is ruled out as a significant contributor to reddening the quasars spectra. We go on to estimate extinctions for our objects assuming their red colors are caused by dust. Continuum fits and Balmer decrements suggest E(B-V) values ranging from near zero to 2.5 magnitudes. Correcting the K-band magnitudes for these extinctions, we find that for K {le} 14.0, red quasars make up between 25% and 60% of the underlying quasar population; owing to the incompleteness of the 2MASS survey at fainter K-band magnitudes, we can only set a lower limit to the radio-detected red quasar population of > 20-30%.

  11. Application of Extended Smoluchowski Equations to Formation of Silver Nanoclusters Generated by Direct Current Magnetron Sputtering Source

    NASA Astrophysics Data System (ADS)

    Zhang, Chuhang; Feng, Yuanxin

    2016-09-01

    We apply the extended Smoluchowski rate equations with neutralization process between nanocluster (NC) anion and cation to study the formation of silver NCs generated by direct current magnetron sputtering (DC-MSP). By comparing the experimental and simulation results, it was found that the origin of size tuning by the cell length was prolonged aggregation time. Size tuning by DC power (P) was attributed to the enhanced initial number density and ionization fraction of the sputtered materials. It was revealed that parts of NC ions were "lost" after aggregation and the amount of lost ions increased with power (20 W < P < 100 W), which was caused by the accelerated neutralization process. The high consistency between experiment and simulation suggests that the extended Smoluchowski rate equations are capable to describe the NC formation in gas phase.

  12. A morphological analysis for searches of possible extended γ-ray sources associated with dark matter annihilation

    NASA Astrophysics Data System (ADS)

    Prokhorov, D. A.; de Jong, S.

    2014-07-01

    We propose a morphological analysis for searches of extended γ-ray emission associated with dark matter annihilation. Our approach is based on the likelihood analysis including the spatial templates produced by taking into account the residual count maps in the energy band where the dark matter annihilation spectrum has a prominent spectral feature. The approach is tested on the example of the possible dark matter annihilation signal from the Virgo cluster of galaxies.

  13. Improvements for extending the time between maintenance periods for the Heidelberg ion beam therapy center (HIT) ion sources

    SciTech Connect

    Winkelmann, Tim Cee, Rainer; Haberer, Thomas; Naas, Bernd; Peters, Andreas; Schreiner, Jochen

    2014-02-15

    The clinical operation at the Heidelberg Ion Beam Therapy Center (HIT) started in November 2009; since then more than 1600 patients have been treated. In a 24/7 operation scheme two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce protons and carbon ions. The modification of the low energy beam transport line and the integration of a third ion source into the therapy facility will be shown. In the last year we implemented a new extraction system at all three sources to enhance the lifetime of extraction parts and reduce preventive and corrective maintenance. The new four-electrode-design provides electron suppression as well as lower beam emittance. Unwanted beam sputtering effects which typically lead to contamination of the insulator ceramics and subsequent high-voltage break-downs are minimized by the beam guidance of the new extraction system. By this measure the service interval can be increased significantly. As a side effect, the beam emittance can be reduced allowing a less challenging working point for the ion sources without reducing the effective beam performance. This paper gives also an outlook to further enhancements at the HIT ion source testbench.

  14. AN ALMA SURVEY OF SUBMILLIMETER GALAXIES IN THE EXTENDED CHANDRA DEEP FIELD SOUTH: SOURCE CATALOG AND MULTIPLICITY

    SciTech Connect

    Hodge, J. A.; Walter, F.; Decarli, R.; Karim, A.; Smail, I.; Swinbank, A. M.; Alexander, D. M.; Danielson, A. L. R.; Edge, A. C.; Biggs, A. D.; De Breuck, C.; Ivison, R. J.; Weiss, A.; Bertoldi, F.; Brandt, W. N.; Chapman, S. C.; Coppin, K. E. K.; Cox, P.; Dannerbauer, H.; Greve, T. R.; and others

    2013-05-01

    We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 {mu}m survey with ALMA (ALESS) has produced maps {approx}3 Multiplication-Sign deeper and with a beam area {approx}200 Multiplication-Sign smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our {approx}1.''6 resolution allows us to measure a size of {approx}9 kpc Multiplication-Sign 5 kpc for the rest-frame {approx}300 {mu}m emission region in one resolved SMG, implying a star formation rate surface density of 80 M{sub Sun} yr{sup -1} kpc{sup -2}, and we constrain the emission regions in the remaining SMGs to be <10 kpc. As the first statistically reliable survey of SMGs, this will provide the basis for an unbiased multiwavelength study of SMG properties.

  15. SED and Emission Line Properties of Red 2MASS AGN

    NASA Astrophysics Data System (ADS)

    Kuraszkiewicz, Joanna; Wilkes, Belinda J.; Schmidt, Gary; Ghosh, Himel

    2009-09-01

    Radio and far-IR surveys, and modeling of the cosmic X-ray background suggest that a large population of obscured AGN has been missed by traditional, optical surveys. The Two Micron All-Sky Survey (2MASS) has revealed a large population (surface density comparable to that of optically selected AGN with Ks<14.5mag) of mostly nearby (median z=0.25), red, moderately obscured AGN, among which 75% are previously unidentified emission-line AGN, with 85% showing broad emission lines. We present the SED and emission line properties of 44 such red (J-Ks>2) 2MASS AGN observed with Chandra. They lie at z<0.37, span a full range of spectral types (Type 1, intermediate, Type 2),Ks-to-X-ray slopes, and polarization (<13%). Their IR-to-X-ray spectral energy distributions (SEDs) are red in the near-IR/opt/UV showing little or no blue bump. The optical colors are affected by reddening, host galaxy emission, redshift, and in few, highly polarized objects, also by scattered AGN light. The levels of obscuration obtained from optical, X-rays, and far-IR imply N_H sources of obscuration: the host galaxy and circumnuclear absorption.

  16. SEARCHES FOR POINT-LIKE AND EXTENDED NEUTRINO SOURCES CLOSE TO THE GALACTIC CENTER USING THE ANTARES NEUTRINO TELESCOPE

    SciTech Connect

    Adrián-Martínez, S.; Ardid, M.; Bou-Cabo, M.; André, M.; Anghinolfi, M.; Anton, G.; Aubert, J.-J.; Bertin, V.; Brunner, J.; Busto, J.; Basa, S.; Biagi, S.; Capone, A.; and others

    2014-05-01

    A search for cosmic neutrino sources using six years of data collected by the ANTARES neutrino telescope has been performed. Clusters of muon neutrinos over the expected atmospheric background have been looked for. No clear signal has been found. The most signal-like accumulation of events is located at equatorial coordinates R.A. = –46.°8 and decl. = –64.°9 and corresponds to a 2.2σ background fluctuation. In addition, upper limits on the flux normalization of an E {sup –2} muon neutrino energy spectrum have been set for 50 pre-selected astrophysical objects. Finally, motivated by an accumulation of seven events relatively close to the Galactic Center in the recently reported neutrino sample of the IceCube telescope, a search for point sources in a broad region around this accumulation has been carried out. No indication of a neutrino signal has been found in the ANTARES data and upper limits on the flux normalization of an E {sup –2} energy spectrum of neutrinos from point sources in that region have been set. The 90% confidence level upper limits on the muon neutrino flux normalization vary between 3.5 and 5.1 × 10{sup –8} GeV cm{sup –2} s{sup –1}, depending on the exact location of the source.

  17. EXSdetect: an end-to-end software for extended source detection in X-ray images: application to Swift-XRT data

    NASA Astrophysics Data System (ADS)

    Liu, T.; Tozzi, P.; Tundo, E.; Moretti, A.; Wang, J.-X.; Rosati, P.; Guglielmetti, F.

    2013-01-01

    Aims: We present a stand-alone software (named EXSdetect) for the detection of extended sources in X-ray images. Our goal is to provide a flexible tool capable of detecting extended sources down to the lowest flux levels attainable within instrumental limitations, while maintaining robust photometry, high completeness, and low contamination, regardless of source morphology. EXSdetect was developed mainly to exploit the ever-increasing wealth of archival X-ray data, but is also ideally suited to explore the scientific capabilities of future X-ray facilities, with a strong focus on investigations of distant groups and clusters of galaxies. Methods: EXSdetect combines a fast Voronoi tessellation code with a friends-of-friends algorithm and an automated deblending procedure. The values of key parameters are matched to fundamental telescope properties such as angular resolution and instrumental background. In addition, the software is designed to permit extensive tests of its performance via simulations of a wide range of observational scenarios. Results: We applied EXSdetect to simulated data fields modeled to realistically represent the Swift X-ray Cluster Survey (SXCS), which is based on archival data obtained by the X-ray telescope onboard the Swift satellite. We achieve more than 90% completeness for extended sources comprising at least 80 photons in the 0.5-2 keV band, a limit that corresponds to 10-14 erg cm-2 s-1 for the deepest SXCS fields. This detection limit is comparable to the one attained by the most sensitive cluster surveys conducted with much larger X-ray telescopes. While evaluating the performance of EXSdetect, we also explored the impact of improved angular resolution and discuss the ideal properties of the next generation of X-ray survey missions. The Phyton code EXSdetect is available on the SXCS website http://adlibitum.oats.inaf.it/sxcs

  18. PHPMyWMS: an open-source-based SVG-oriented framework for extended Web map services

    NASA Astrophysics Data System (ADS)

    Behr, F.-J.; Hui, L.; Hang, C.; Weldeslasie, F.; Zhuoer, C.

    2006-10-01

    The Web Map Server Implementation Specification (WMS), originally developed and published by the Open Geospatial Consortium, was finally adopted by ISO as an international standard. According to this standard maps are presented either in "picture" formats or "graphic element" formats. While the pictorial (visual) representation uses raster formats, graphic element formats include Scalable Vector Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) format. In this paper a framework for supporting Web Map Services using SVG will be presented. Geo-data, converted to SVG, is stored in a database management system, retrieved by the WMS server upon user request and transferred - optionally compressed - through the Internet. Finally it is visualized in Web browsers on desktop computes or mobile devices, natively or using plug-ins extending the browser's functionality. Besides supporting the WMS request GetCapabilities, GetMap and GetFeatureInfo requests, additional formats and extensions have been included in this framework. The development proves that open, XML-based standards in combination with modern programming languages and integrated development environments allow rapid implementation of recommendations and standards in geo-informatics.

  19. Red fresh vegetables smoothies with extended shelf life as an innovative source of health-promoting compounds.

    PubMed

    Castillejo, Noelia; Martínez-Hernández, Ginés Benito; Gómez, Perla A; Artés, Francisco; Artés-Hernández, Francisco

    2016-03-01

    Two fresh red vegetables smoothies based on tomato, carrots, pepper and broccoli and rich in health-promoting compounds were developed. The smoothies showed a viscoelastic behaviour. According to sensory analyses, a shelf life of 28 days at 5 °C for fresh blended smoothies was established while thermally-treated ones (3 min, 80 °C) reached up to 40 days at 20 °C and 58 days at 5 °C. For those mild heat treated smoothies, total vitamin C degradation was 2-fold reduced during storage at 5 °C compared to samples stored at 20 °C while the initial total carotenoids, lycopene and total chlorophylls contents were not greatly affected. A 250-g portion of such smoothies covers in a great extend the established recommended daily nutrient intakes for dietary fibre, minerals and vitamin C of different population groups. As main conclusion, a mild thermal treatment and low temperature storage greatly increased the shelf life of red fresh vegetables smoothies and reduced total vitamin C degradation. PMID:27570272

  20. Red fresh vegetables smoothies with extended shelf life as an innovative source of health-promoting compounds.

    PubMed

    Castillejo, Noelia; Martínez-Hernández, Ginés Benito; Gómez, Perla A; Artés, Francisco; Artés-Hernández, Francisco

    2016-03-01

    Two fresh red vegetables smoothies based on tomato, carrots, pepper and broccoli and rich in health-promoting compounds were developed. The smoothies showed a viscoelastic behaviour. According to sensory analyses, a shelf life of 28 days at 5 °C for fresh blended smoothies was established while thermally-treated ones (3 min, 80 °C) reached up to 40 days at 20 °C and 58 days at 5 °C. For those mild heat treated smoothies, total vitamin C degradation was 2-fold reduced during storage at 5 °C compared to samples stored at 20 °C while the initial total carotenoids, lycopene and total chlorophylls contents were not greatly affected. A 250-g portion of such smoothies covers in a great extend the established recommended daily nutrient intakes for dietary fibre, minerals and vitamin C of different population groups. As main conclusion, a mild thermal treatment and low temperature storage greatly increased the shelf life of red fresh vegetables smoothies and reduced total vitamin C degradation.

  1. Temperature Measurement of a Miniature Ceramic Heater in the Presence of an Extended Interfering Background Radiation Source Using a Multiwavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1999-01-01

    Temperature measurement of small (millimeter size) objects is generally difficult and demanding. Measurement involving ceramic materials using the traditional one- and two-color pyrometer is difficult because of their complex optical properties, such as low emissivity which may vary with both temperature and wavelength. Pyrometry applications in an environment with an interfering radiation source of extended dimension adds extra complexity to the process. We show that the multiwavelength pyrometer successfully measured the temperatures of a millimeter (mm) size ceramic heater under these demanding conditions.

  2. EMERGENCY ROOM: AN UNRECOGNIZED SOURCE OF EXTENDED-SPECTRUM β-LACTAMASE PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE.

    PubMed

    Pornsinchai, Pornsook; Chongtrakool, Piriyaporn; Diraphat, Pornphan; Siripanichgon, Kanokrat; Malathum, Kumthorn

    2015-01-01

    Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae are the leading causes of hospital-associated infections, but community-acquired cases are increasingly being reported. This study determined the prevalence of ESBL-producing E. coli and K. pneumoniae carriers, their bla genes and risk factors of 452 patients admitted to the emergency room (ER) of Ramathibodi Hospital, Mahidol University, Bangkok, Thailand between April and August 2011. Prevalence of ESBL-producing E. coli and K. pneumoniae from rectal swabs was 16.5% and 1.0%, respectively. Factors associated with ESBL-producing carriers were a previous history of hospital admission (p = 0.001) and visits to health care facilities (p = 0.002) during the previous 3 months. All ESBL-producing isolates were susceptible to imipenem, meropenem and ertapenem. The majority (78%) of ESBL-producing E. coli isolates showed very high resistance to cefotaxime and ceftriaxone (MIC50 and MIC90 > 256 µg/ml). ESBL-producing E. coli harbored chromosomal blaTEM (96%), blaCTX-M (70%) and blaSHV (1%), while 8%, 73% and 3%, respectively, were located on plasmid. The prevalence of these genes in ESBL-producing K. pneumoniae was 75%, 50% and 25%, respectively on chromosome; and 100%, 25% and 50%, respectively on plasmid. Nucleotide sequence analysis revealed that these bla genes were of the type blaTEM-1' blaTEM-116' blaCTX-M-15' blaCTX-M-161' blaSHV-12, blaSHV-28 and blaSHV-148. Detailed epidemiologic and clinical characteristics of ER patients with history of prior hospital visits should be carried out to identify the ESBL-producing organisms they have acquired in order to institute appropriate treatment for these patients as well as control measures against further dissemination of these life-threatening organisms. PMID:26513905

  3. The 2 Ms Chandra Deep Field-North Survey and the 250 ks Extended Chandra Deep Field-South Survey: Improved Point-source Catalogs

    NASA Astrophysics Data System (ADS)

    Xue, Y. Q.; Luo, B.; Brandt, W. N.; Alexander, D. M.; Bauer, F. E.; Lehmer, B. D.; Yang, G.

    2016-06-01

    We present improved point-source catalogs for the 2 Ms Chandra Deep Field-North (CDF-N) and the 250 ks Extended Chandra Deep Field-South (E-CDF-S) Surveys, implementing a number of recent improvements in Chandra source-cataloging methodology. For CDF-N/E-CDF-S, we provide a main catalog that contains 683/1003 X-ray sources detected with wavdetect at a false-positive probability threshold of 10-5 that also satisfy a binomial-probability source-selection criterion of P\\lt 0.004/P < 0.002. Such an approach maximizes the number of reliable sources detected: a total of 196/275 main-catalog sources are new compared to the Alexander et al. CDF-N/Lehmer et al. E-CDF-S main catalogs. We also provide CDF-N/E-CDF-S supplementary catalogs that consist of 72/56 sources detected at the same wavdetect threshold and having P of 0.004-0.1/0.002-0.1 and {K}s≤slant 22.9/{K}s≤slant 22.3 mag counterparts. For all ≈ 1800 CDF-N and E-CDF-S sources, including the ≈ 500 newly detected ones (these being generally fainter and more obscured), we determine X-ray source positions utilizing centroid and matched-filter techniques; we also provide multiwavelength identifications, apparent magnitudes of counterparts, spectroscopic and/or photometric redshifts, basic source classifications, and estimates of observed active galactic nucleus and galaxy source densities around respective field centers. Simulations show that both the CDF-N and E-CDF-S main catalogs are highly reliable and reasonably complete. Background and sensitivity analyses indicate that the on-axis mean flux limits reached represent a factor of ≈ 1.5-2.0 improvement over the previous CDF-N and E-CDF-S limits. We make our data products publicly available.

  4. THE SECOND ULTRALUMINOUS X-RAY SOURCE TRANSIENT IN M31: CHANDRA, HUBBLE SPACE TELESCOPE, AND XMM OBSERVATIONS, AND EVIDENCE FOR AN EXTENDED CORONA

    SciTech Connect

    Barnard, R.; Garcia, M.; Murray, S. S.

    2013-08-01

    XMMU J004243.6+412519 is a transient X-ray source in M31, first discovered 2012 January 15. Different approaches to fitting the brightest follow-up observation gave luminosities 1.3-2.5 Multiplication-Sign 10{sup 39} erg s{sup -1}, making it the second ultraluminous X-ray source (ULX) in M31, with a probable black hole accretor. These different models represent different scenarios for the corona: optically thick and compact, or optically thin and extended. We obtained Chandra ACIS and Hubble Space Telescope Advanced Camera for Surveys observations of this object as part of our transient monitoring program, and also observed it serendipitously in a 120 ks XMM-Newton observation. We identify an optical counterpart at J2000 position 00:42:43.70 +41:25:18.54; its F435W ({approx}B band) magnitude was 25.97 {+-} 0.03 in the 2012 March 7 observation, and >28.4 at the 4{sigma} level during the 2012 September 7 observation, indicating a low-mass donor. We created two alternative light curves, using the different corona scenarios, finding linear decay for the compact corona and exponential decay for the extended corona; linear decay implies a disk that is >5 mag brighter than we observed. We therefore favor the extended corona scenario, but caution that there is no statistical preference for this model in the X-ray spectra alone. Using two empirical relations between the X-ray to optical ratio and the orbital period, we estimate a period of {approx}9-30 hr; this period is consistent with that of the first ULX in M31 (18{sup +5}{sub -6} hr)

  5. Photometric analysis of the eclipsing binary 2MASS 19090585+4911585

    NASA Astrophysics Data System (ADS)

    Raetz, St.; Vaňko, M.; Mugrauer, M.; Schmidt, T. O. B.; Roell, T.; Eisenbeiss, T.; Hohle, M. M.; Koeltzsch, A.; Ginski, Ch.; Marka, C.; Moualla, M.; Tetzlaff, N.; Broeg, Ch.; Neuhäuser, R.

    2009-05-01

    We report on observations of the eclipsing binary 2MASS 19090585+4911585 with the 25 cm auxiliary telescope of the University Observatory Jena. We show that a nearby brighter star (2MASS 19090783+4912085) was previously misclassified as the eclipsing binary and find 2MASS 19090585+4911585 to be the true source of variation. We present photometric analysis of V RI light curves. The system is an overcontact binary of W UMa type with an orbital period of (0.288374 ± 0.000010) d. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University Jena.

  6. Source apportionment for sediment PAHs from the Daliao River (China) using an extended fit measurement mode of chemical mass balance model.

    PubMed

    Chen, Hai-Yang; Teng, Yan-Guo; Wang, Jin-Sheng

    2013-02-01

    To minimize the selection uncertainties of source profiles and obtain the higher model performance, an extended fit measurement mode for chemical mass balance model (EFMM-CMB) was proposed and applied to estimate source contributions for sediment PAHs from the Daliao River around which is the important industrial bases with oil, chemical and steel factories in the northeast part of China. Based on least squares fitting method, EFMM-CMB initially calculated the fit measurement index to every one of the possible combinations that can be made from the source profiles. Any successful applications of the fitting method were ranked according to performance measures, and then determined by maximizing an overall fitting index for a unique solution. Apportionment results from two case scenarios showed that the values of performance measures for EFMM-CMB were better to that for CMB8.2 results. With species selection of high molecular weight PAHs, power plant (45.75%), biomass burning (29.34%) and traffic tunnel (10.59%) were identified as the major sources of sediment PAHs from the Daliao River region.

  7. UV-TO-FIR ANALYSIS OF SPITZER/IRAC SOURCES IN THE EXTENDED GROTH STRIP. I. MULTI-WAVELENGTH PHOTOMETRY AND SPECTRAL ENERGY DISTRIBUTIONS

    SciTech Connect

    Barro, Guillermo; Perez-Gonzalez, P. G.; Gallego, J.; Villar, V.; Zamorano, J.; Ashby, M. L. N.; Kajisawa, M.; Yamada, T.; Miyazaki, S.

    2011-03-15

    We present an IRAC 3.6+4.5 {mu}m selected catalog in the Extended Groth Strip (EGS) containing photometry from the ultraviolet to the far-infrared and stellar parameters derived from the analysis of the multi-wavelength data. In this paper, we describe the method used to build coherent spectral energy distributions (SEDs) for all the sources. In a forthcoming companion paper, we analyze those SEDs to obtain robust estimations of stellar parameters such as photometric redshifts, stellar masses, and star formation rates. The catalog comprises 76,936 sources with [3.6] {<=} 23.75 mag (85% completeness level of the IRAC survey in the EGS) over 0.48 deg{sup 2}. For approximately 16% of this sample, we are able to deconvolve the IRAC data to obtain robust fluxes for the multiple counterparts found in ground-based optical images. Typically, the SEDs of the IRAC sources in our catalog count with more than 15 photometric data points, spanning from the ultraviolet wavelengths probed by GALEX to the far-infrared observed by Spitzer, and going through ground- and space-based optical and near-infrared data taken with 2-8 m class telescopes. Approximately 95% and 90% of all IRAC sources are detected in the deepest optical and near-infrared bands. These fractions are reduced to 85% and 70% for S/N > 5 detections in each band. Only 10% of the sources in the catalog have optical spectroscopy and redshift estimations. Almost 20% and 2% of the sources are detected by MIPS at 24 and 70 {mu}m, respectively. We also cross-correlate our catalog with public X-ray and radio catalogs. Finally, we present the Rainbow Navigator public Web interface utility, designed to browse all the data products resulting from this work, including images, spectra, photometry, and stellar parameters.

  8. 2MASS J22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse

    NASA Astrophysics Data System (ADS)

    Kjurkchieva, D.; Khruzina, T.; Dimitrov, D.; Groebel, R.; Ibryamov, S.; Nikolov, G.

    2015-12-01

    Context. The SW Sex stars are assumed to represent a distinguished stage in cataclysmic variable (CV) evolution, making it especially important to study them. Aims: We discovered a new cataclysmic star and carried out prolonged and precise photometric observations, as well as medium-resolution spectral observations. Modelling these data allowed us to determine the physical parameters and to establish its peculiarities. Methods: To obtain a light curve solution we used model whose emission sources are a white dwarf surrounded by an accretion disk with a hot spot, a gaseous stream near the disk's lateral side, and a secondary star filling its Roche lobe. The obtained physical parameters are compared with those of other SW Sex-subtype stars. Results: The newly discovered cataclysmic variable 2MASS J22560844+5954299 shows the deepest eclipse amongst the known nova-like stars. It was reproduced by totally covering a very luminous accretion disk by a red secondary component. The temperature distribution of the disk is flatter than that of steady-state disk. The target is unusual with the combination of a low mass ratio q ~ 1.0 (considerably below the limit q = 1.2 of stable mass transfer of CVs) and an M-star secondary. The intensity of the observed three emission lines, Hα, He 5875, and He 6678, sharply increases around phase 0.0, accompanied by a Doppler jump to the shorter wavelength. The absence of eclipses of the emission lines and their single-peaked profiles means that they originate mainly in a vertically extended hot-spot halo. The emission Hα line reveals S-wave wavelength shifts with semi-amplitude of around 210 km s-1 and phase lag of 0.03. Conclusions: The non-steady-state emission of the luminous accretion disk of 2MASS J22560844+5954299 was attributed to the low viscosity of the disk matter caused by its unusually high temperature. The star shows all spectral properties of an SW Sex variable apart from the 0.5 central absorption. Based on data collected

  9. THE EXTENDED CHANDRA DEEP FIELD-SOUTH SURVEY: OPTICAL SPECTROSCOPY OF FAINT X-RAY SOURCES WITH THE VLT AND KECK

    SciTech Connect

    Silverman, J. D.; Mainieri, V.; Rosati, P.; Salvato, M.; Hasinger, G.; Bergeron, J.; Capak, P.; Szokoly, G.; Gilli, R.; Tozzi, P.; Vignali, C.; Alexander, D. M.; Brandt, W. N.; Luo, B.; Rafferty, D.; Xue, Y. Q.; Lehmer, B. D.; Bauer, F. E.

    2010-11-15

    We present the results of a program to acquire high-quality optical spectra of X-ray sources detected in the Extended-Chandra Deep Field-South (E-CDF-S) and its central 2 Ms area. New spectroscopic redshifts, up to z = 4, are measured for 283 counterparts to Chandra sources with deep exposures (t {approx} 2-9 hr per pointing) using multi-slit facilities on both VLT (VIMOS) and Keck (DEIMOS), thus bringing the total number of spectroscopically identified X-ray sources to over 500 in this survey field. Since our new spectroscopic identifications are mainly associated with X-ray sources in the shallower 250 ks coverage, we provide a comprehensive catalog of X-ray sources detected in the E-CDF-S including the optical and near-infrared counterparts, determined by a likelihood routine, and redshifts (both spectroscopic and photometric), that incorporate published spectroscopic catalogs, thus resulting in a final sample with a high fraction (80%) of X-ray sources having secure identifications. We demonstrate the remarkable coverage of the luminosity-redshift plane now accessible from our data while emphasizing the detection of active galactic nuclei (AGNs) that contribute to the faint end of the luminosity function (L {sub 0.5-8keV} {approx} 10{sup 43}-10{sup 44} erg s{sup -1}) at 1.5 {approx}< z {approx}< 3 including those with and without broad emission lines. Our redshift catalog includes 17 type-2 QSOs at 1 {approx}< z {approx}< 3.5 that significantly increases such samples (2x). Based on our deepest (9 hr) VLT/VIMOS observation, we identify 'elusive' optically faint galaxies (R {sub mag} {approx} 25) at z {approx} 2-3 based upon the detection of interstellar absorption lines (e.g., O II+Si IV, C II], C IV); we highlight one such case, an absorption-line galaxy at z = 3.208 having no obvious signs of an AGN in its optical spectrum. In addition, we determine accurate distances to eight galaxy groups with extended X-ray emission detected both by Chandra and XMM

  10. Development of Extended-Depth Swept Source Optical Coherence Tomography for Applications in Ophthalmic Imaging of the Anterior and Posterior Eye

    NASA Astrophysics Data System (ADS)

    Dhalla, Al-Hafeez Zahir

    extending the imaging range of OCT systems are developed. These techniques include the use of a high spectral purity swept source laser in a full-field OCT system, as well as the use of a peculiar phenomenon known as coherence revival to resolve the complex conjugate ambiguity in swept source OCT. In addition, a technique for extending the depth of focus of OCT systems by using a polarization-encoded, dual-focus sample arm is demonstrated. Along the way, other related advances are also presented, including the development of techniques to reduce crosstalk and speckle artifacts in full-field OCT, and the use of fast optical switches to increase the imaging speed of certain low-duty cycle swept source OCT systems. Finally, the clinical utility of these techniques is demonstrated by combining them to demonstrate high-speed, high resolution, extended-depth imaging of both the anterior and posterior eye simultaneously and in vivo.

  11. The effect of an extended source-to-skin distance in the treatment of the spinal field in children receiving craniospinal irradiation

    SciTech Connect

    Koshy, Mary; Paulino, Arnold C.; Marcus, Robert B.; Ting, Joseph

    2004-03-31

    In this study, we compared a single extended source-to-skin difference (SSD) spinal field and the alternative 2-field gapped approach at 100 SSD on dose to surrounding normal tissues. Five female patients ranging in age from 3 to 20 years underwent computed tomography (CT) simulation for treatment planning of the craniospinal axis, which was treated in its entirety to 36 Gy. For each slice, the clinical target volume (thecal sac and contents), mandible, thyroid gland, esophagus, heart, lungs, liver, and ovaries were contoured. Technique A employed the use of a single posterior spinal field delivered at SSD = 140 cm (140 SSD), and Technique B employed the use of 2 gapped spinal fields using a traditional SSD of 100 cm (100 SSD). Dose-volume histograms (DVHs) were obtained for each organ contoured and for each technique used. In all patients, the average mean dose to all surrounding structures was increased with the use of a single extended SSD (Technique A) when compared to the 2 spinal fields prescribed at 100 SSD (Technique B). The average mean doses to the mandible, thyroid gland, esophagus, and heart were 78%, 19%, 6%, and 16%, respectively, higher with Technique A as compared to Technique B. In addition, the average mean doses to the lungs, liver, and ovaries were 53%, 33% and 69%, respectively, higher as compared to Technique B. However, the clinical target volume at the spinal junction site received a less homogenous dose with Technique B as compared to Technique A. We conclude that although the use of a single-field extended SSD delivered a more homogenous dose to the spine, a higher dose to the ovaries, thyroid gland, mandible, lungs, liver, and heart was seen.

  12. SU-E-T-623: Delivery of 3D Conformal Proton-Therapy Fields at Extended Source- To-Axis Distances

    SciTech Connect

    Kryck, E; Slopsema, R

    2014-06-15

    Purpose: To evaluate the dosimetric properties of proton dose distributions delivered at extended source-to-skin distances (SSD). Methods: Radiation was delivered with a gantry-mounted proton double scattering system (Proteus 230, IBA). This system has a maximum field diameter of 24 cm at isocenter and a nominal source-to-axis distance of 230 cm. Dose was measured at nominal SSD as well as at -10, +10, +25, +50, +75, and +100 cm for several range and modulation width combinations. Depth dose distributions were measured with a multi-layer ionization chamber (MLIC), and lateral dose distributions with a 2D ionization chamber array as well as with a diode in a water phantom. Results: The maximum field diameter was found to increase from 24.0 cm at nominal SSD to 29.1 cm and 33.3 cm at +50 cm and +100 cm respectively. Field flatness remained below 3% for all SSD. Tilt in the spread-out Bragg peak depth dose distribution increased with SSD up to 0.4 %-per-g/cm2 at +100 cm. The measured range decreased with 1.1x10-3 g/cm2 per centimeter shift in SSD due to proton energy loss in air, very close to the theoretically calculated value of 1.06x10-3 g/cm3. The output and dose rate decrease with the inverse of the SSD squared as expected. Conclusion: Extending the SSD up to 100 cm increases the maximum field diameter from 24.0 cm to 33.3 cm while the dose uniformity remains acceptable.

  13. Evaluation of the feasibility of alcohols serving as external carbon sources for biological phosphorus removal induced by the oxic/extended-idle regime.

    PubMed

    Wang, Dongbo; Zheng, Wei; Li, Xiaoming; Yang, Qi; Liao, Dexiang; Zeng, Guangming

    2013-03-01

    Recently, a novel operational regime (i.e., the oxic/extended-idle [OEI] regime) has been reported to successfully achieve enhanced biological phosphorus removal (EBPR) when employing glucose and volatile fatty acids as the sole substrate. In the OEI regime, polyphosphate accumulating organisms (PAOs) could get a selective advantage over other populations during the extended-idle period where polyphosphate released but polyhydroxyalkanoates and glycogen transformations were negligible/low, thus energy requirements for maintenance purposes in the period could be covered by polyphosphate release. This study further evaluated the feasibility of alcohols as external carbon sources for EBPR induced by the OEI regime, as the available substrate in the raw wastewater is often deficient. First, phosphorus removal in the OEI process was compared, respectively, with methanol and ethanol as the sole substrate. The results showed that the ethanol-reactor achieved 90.8 ± 2.3% of phosphorus removal, which was approximate twofold than the methanol-reactor. Further studies displayed that the cells in the ethanol-reactor contained more PAOs, and had higher activities of exopolyphosphatase and polyphosphate kinase than those in the methanol-reactor. Also, the aerobic transformations of polyhydroxyalkanoates and glycogen in the ethanol-reactor were, respectively, higher and lower than those in the methanol-reactor, which were consistent with the reactors performances. Then, the feasibility of using ethanol as external substrate to enhance EBPR in the OEI process was confirmed for a municipal wastewater. Finally, EBPR performance and metabolic transformation values between the OEI and the anaerobic/oxic (A/O) regimes with ethanol as the sole substrate were compared. The results showed that EBPR in the ethanol-OEI reactor was higher than that in the ethanol-A/O reactor. All the above results proved that ethanol was a favorable external substrate to the OEI regime for EBPR enhancement.

  14. UV-TO-FIR ANALYSIS OF SPITZER/IRAC SOURCES IN THE EXTENDED GROTH STRIP. II. PHOTOMETRIC REDSHIFTS, STELLAR MASSES, AND STAR FORMATION RATES

    SciTech Connect

    Barro, G.; Perez-Gonzalez, P. G.; Gallego, J.; Villar, V.; Zamorano, J.; Ashby, M. L. N.; Kajisawa, M.; Yamada, T.; Miyazaki, S.

    2011-04-01

    Based on the ultraviolet to far-infrared photometry already compiled and presented in a companion paper (Paper I), we present a detailed spectral energy distribution (SED) analysis of nearly 80,000 IRAC 3.6 + 4.5 {mu}m selected galaxies in the Extended Groth Strip. We estimate photometric redshifts, stellar masses, and star formation rates (SFRs) separately for each galaxy in this large sample. The catalog includes 76,936 sources with [3.6] {<=} 23.75 (85% completeness level of the IRAC survey) over 0.48 deg{sup 2}. The typical photometric redshift accuracy is {Delta}z/(1 + z) = 0.034, with a catastrophic outlier fraction of just 2%. We quantify the systematics introduced by the use of different stellar population synthesis libraries and initial mass functions in the calculation of stellar masses. We find systematic offsets ranging from 0.1 to 0.4 dex, with a typical scatter of 0.3 dex. We also provide UV- and IR-based SFRs for all sample galaxies, based on several sets of dust emission templates and SFR indicators. We evaluate the systematic differences and goodness of the different SFR estimations using the deep FIDEL 70 {mu}m data available in the Extended Groth Strip. Typical random uncertainties of the IR-bases SFRs are a factor of two, with non-negligible systematic effects at z {approx}> 1.5 observed when only MIPS 24 {mu}m data are available. All data products (SEDs, postage stamps from imaging data, and different estimations of the photometric redshifts, stellar masses, and SFRs of each galaxy) described in this and the companion paper are publicly available, and they can be accessed through our the Web interface utility Rainbow-navigator.

  15. The search for red AGN with 2MASS

    NASA Technical Reports Server (NTRS)

    Cutri, R. M.; Nelson, B. O.; Kirkpatrick, J. D.; Huchra, J. P.; Smith, P. S.

    2001-01-01

    We present the results of a simple, highly efficient 2MASS color-based survey that has already discovered 140 previously unknown red AGN and QSOs. These objects are near-infrared-bright and relatively nearby; the media redshift of the sample is z=0.25, and all but two have z<0.7.

  16. Inferring Milky Way Structure from 2MASS-selected Carbon Stars

    NASA Astrophysics Data System (ADS)

    Skrutskie, M. F.; Reber, T. J.; Murphy, N. W.; Weinberg, M. D.

    2001-12-01

    We present a reconstructed view of the Milky Way disk using 40,000 carbon star candidates extracted from the Two Micron All Sky Survey (2MASS). These candidates can be selected with high reliability using a technique which distinguishes the intrinsically red colors of carbon stars (and other extreme AGB) from reddened stars in the Galactic plane using 2MASS photometry alone. The extracted sources serve as crude standard candles with a dispersion of 0.3 mag. The complete stellar bar and the far edge of the Galactic disk are evident in this analysis. We further infer parameters for the central bar and for disk scale lengths and scale heights using this population.

  17. Near-infrared Variability in the 2MASS Calibration Fields: A Search for Planetary Transit Candidates

    NASA Technical Reports Server (NTRS)

    Plavchan, Peter; Jura, M.; Kirkpatrick, J. Davy; Cutri, Roc M.; Gallagher, S. C.

    2008-01-01

    The Two Micron All Sky Survey (2MASS) photometric calibration observations cover approximately 6 square degrees on the sky in 35 'calibration fields,' each sampled in nominal photometric conditions between 562 and 3692 times during the 4 years of the 2MASS mission. We compile a catalog of variables from the calibration observations to search for M dwarfs transited by extrasolar planets. We present our methods for measuring periodic and nonperiodic flux variability. From 7554 sources with apparent K(sub s) magnitudes between 5.6 and 16.1, we identify 247 variables, including extragalactic variables and 23 periodic variables. We have discovered three M dwarf eclipsing systems, including two candidates for transiting extrasolar planets.

  18. The IC 5146 star forming complex and its surroundings with 2MASS, WISE and Spitzer

    NASA Astrophysics Data System (ADS)

    Nunes, N. A.; Bonatto, C.; Bica, E.

    2016-02-01

    Throughout the last decade sensitive infrared observations obtained by the Spitzer Space Telescope significantly increased the known population of YSOs associated with nearby molecular clouds. With such a census recent studies have characterized pre-main sequence stars (PMS) and determined parameters from different wavelengths. Given the restricted Spitzer coverage of some of these clouds, relative to their extended regions, these YSO populations may represent a limited view of star formation in these regions. We are taking advantage of mid-infrared observations from the NASA Wide Field Infrared Survey Explorer (WISE), which provides an all sky view and therefore full coverage of the nearby clouds, to assess the degree to which their currently known YSO population may be representative of a more complete population. We extend the well established classification method of the Spitzer Legacy teams to archived WISE observations. We have adopted 2MASS photometry as a "standard catalogue" for comparisons. Besides the massive embedded cluster IC 5146 we provide a multiband view of five new embedded clusters in its surroundings that we discovered with WISE. In short, the analysis involves the following for the presently studied cluster sample: (i) extraction of 2MASS/WISE/Spitzer photometry in a wide circular region; (ii) field-star decontamination to enhance the intrinsic Colour-magnitude diagram (CMD) morphology (essential for a proper derivation of reddening, age, and distance from the Sun); and (iii) construction of Colour-magnitude filters, for more contrasted stellar radial density profiles (RDPs).

  19. 2MASS J20261584-2943124: AN UNRESOLVED L0.5 + T6 SPECTRAL BINARY

    SciTech Connect

    Gelino, Christopher R.; Burgasser, Adam J.

    2010-07-15

    We identify the L dwarf 2MASS J20261584-2943124 as an unresolved spectral binary, based on low-resolution, near-infrared spectroscopy from IRTF/SpeX. The data reveal a peculiar absorption feature at 1.6 {mu}m, previously noted in the spectra of other very low-mass spectral binaries, which likely arises from overlapping FeH and CH{sub 4} absorption bands in the blended light of an L dwarf/T dwarf pair. Spectral template matching analysis indicates component types of L0.5 and T6, with relative brightness {Delta}H = 4.2 {+-} 0.6. Laser guide star adaptive optics imaging observations with Keck/NIRC2 fail to resolve the source, indicating a maximum separation at the observing epoch of 0.''25, or a projected separation of 9 AU assuming a distance of 36 {+-} 5 pc. With an age that is likely to be relatively older ({approx}>5 Gyr) based on the system's large V{sub tan} and mass ratio arguments, the relative motion of the potentially 'massive' (0.06-0.08 M{sub sun}) components of 2MASS J2026-2943 may be detectable through radial velocity variations, like its earlier-type counterpart 2MASS J03202839-0446358 (M8+T5), providing dynamical mass measurements that span the hydrogen burning limit.

  20. DETECTION OF RADIO EMISSION FROM THE HYPERACTIVE L DWARF 2MASS J13153094-2649513AB

    SciTech Connect

    Burgasser, Adam J.; Melis, Carl; Zauderer, B. Ashley; Berger, Edo

    2013-01-01

    We report the detection of radio emission from the unusually active L5e + T7 binary 2MASS J13153094-2649513AB made with the Australian Telescope Compact Array. Observations at 5.5 GHz reveal an unresolved source with a continuum flux of 370 {+-} 50 {mu}Jy, corresponding to a radio luminosity of L{sub rad} = {nu}L{sub {nu}} = (9 {+-} 3) Multiplication-Sign 10{sup 23} erg s{sup -1} and log{sub 10} L{sub rad}/L{sub bol} = -5.44 {+-} 0.22. No detection is made at 9.0 GHz to a 5{sigma} limit of 290 {mu}Jy, consistent with a power-law spectrum S{sub {nu}}{proportional_to}{nu}{sup -{alpha}} with {alpha} {approx}> 0.5. The emission is quiescent, with no evidence of variability or bursts over three hours of observation, and no measurable polarization (V/I < 34%). 2MASS J1315-2649AB is one of the most radio-luminous ultracool dwarfs detected in quiescent emission to date, comparable in strength to other cool sources detected in outburst. Its detection indicates no decline in radio flux through the mid-L dwarfs. It is unique among L dwarfs in having strong and persistent H{alpha} and radio emission, indicating the coexistence of a cool, neutral photosphere (low electron density) and a highly active chromosphere (high electron density and active heating). These traits, coupled with the system's mature age and substellar secondary, make 2MASS J1315-2649AB an important test for proposed radio emission mechanisms in ultracool dwarfs.

  1. Detection of Radio Emission from the Hyperactive L Dwarf 2MASS J13153094-2649513AB

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Melis, Carl; Zauderer, B. Ashley; Berger, Edo

    2013-01-01

    We report the detection of radio emission from the unusually active L5e + T7 binary 2MASS J13153094-2649513AB made with the Australian Telescope Compact Array. Observations at 5.5 GHz reveal an unresolved source with a continuum flux of 370 ± 50 μJy, corresponding to a radio luminosity of L rad = νL ν = (9 ± 3)×1023 erg s-1 and log10 L rad/L bol = -5.44 ± 0.22. No detection is made at 9.0 GHz to a 5σ limit of 290 μJy, consistent with a power-law spectrum S νvpropν-α with α >~ 0.5. The emission is quiescent, with no evidence of variability or bursts over three hours of observation, and no measurable polarization (V/I < 34%). 2MASS J1315-2649AB is one of the most radio-luminous ultracool dwarfs detected in quiescent emission to date, comparable in strength to other cool sources detected in outburst. Its detection indicates no decline in radio flux through the mid-L dwarfs. It is unique among L dwarfs in having strong and persistent Hα and radio emission, indicating the coexistence of a cool, neutral photosphere (low electron density) and a highly active chromosphere (high electron density and active heating). These traits, coupled with the system's mature age and substellar secondary, make 2MASS J1315-2649AB an important test for proposed radio emission mechanisms in ultracool dwarfs.

  2. Extended BCDM

    NASA Astrophysics Data System (ADS)

    Occhionero, Franco; Baccigalupi, Carlo; Amendola, Luca

    1999-05-01

    We propose a new inflationary toy model that produces two episodes of phase transitions. With the first one, super-horizon-sized bubbles are nucleated, which are seen from inside as open universes, thereby reconciling inflation with the recent observations of a low Ω0. With the second transition, a distribution of sub-horizon voids, of sizes typically around 10-100 Mpc/h are generated inside the open universes. These primordial voids can be the seeds of the present large scale voids that are detected in redshift surveys, and provide a non-Gaussian signal on the microwave background. The model realizes this sequence along the same slow-rolling path, by modulating the energy difference between the vacuum states. In this model, that we call extended Bubbly CDM, openness and bubblyness, rather than flatness and homogeneity, are the main products of inflation.

  3. The 2 Ms Chandra Deep Field-North Survey and the 250 ks Extended Chandra Deep Field-South Survey: Improved Point-Source Catalogs

    NASA Astrophysics Data System (ADS)

    Xue, Y.; Luo, B.; Brandt, W.; Alexander, D.; Bauer, F.; Lehmer, B.; Yang, G.

    2016-06-01

    We present improved point-source catalogs for the 2Ms CDF-N and the 250ks E-CDF-S, implementing a number of recent improvements in Chandra source-cataloging methodology. For the CDF-N/E-CDF-S, we provide a main catalog that contains 683/1003 X-ray sources detected with wavdetect at a false-positive probability threshold of 1E-5 that also satisfy a binomial-probability source-selection criterion of P<0.004/P<0.002. Such an approach maximizes the number of reliable sources detected: a total of 196/275 main-catalog sources are new compared to the A03 CDF-N/L05 E-CDF-S main catalogs. We also provide CDF-N/E-CDF-S supplementary catalogs that consist of 72/56 sources detected at the same wavdetect threshold and having P of 0.004-0.1/0.002-0.1 and K_s<22.9/K_s<22.3 counterparts. For all ≈1800 CDF-N and E-CDF-S sources, including the ≈500 newly detected ones, we determine X-ray source positions utilizing centroid and matched-filter techniques; we also provide multiwavelength identifications, apparent magnitudes of counterparts, spectroscopic and/or photometric redshifts, basic source classifications, and estimates of observed AGN and galaxy source densities around respective field centers. Simulations show that both the CDF-N and E-CDF-S main catalogs are highly reliable and reasonably complete. Background and sensitivity analyses indicate that the on-axis mean flux limits reached represent a factor of ≈1.5-2.0 improvement over the previous CDF-N and E-CDF-S limits.

  4. Discovery of an X-Ray-emitting Contact Binary System 2MASS J11201034‑2201340

    NASA Astrophysics Data System (ADS)

    Hu, Chin-Ping; Yang, Ting-Chang; Chou, Yi; Liu, L.; Qian, S.-B.; Hui, C. Y.; Kong, Albert K. H.; Lin, L. C. C.; Tam, P. H. T.; Li, K. L.; Ngeow, Chow-Choong; Chen, W. P.; Ip, Wing-Huen

    2016-06-01

    We report the detection of orbital modulation, a model solution, and the X-ray properties of a newly discovered contact binary, Two Micron All Sky Survey (2MASS) J11201034‑2201340. We serendipitously found this X-ray point source outside the error ellipse when searching for possible X-ray counterparts of γ-ray millisecond pulsars among the unidentified objects detected by the Fermi Gamma-ray Space Telescope. The optical counterpart of the X-ray source (unrelated to the γ-ray source) was then identified using archival databases. The long-term Catalina Real-Time Transient Survey detected a precise signal with a period of P=0.28876208(56) days. A follow-up observation made by the Super Light Telescope of Lulin Observatory revealed the binary nature of the object. Utilizing archived photometric data of multi-band surveys, we construct the spectral energy distribution (SED), which is well fit by a K2V spectral template. The fitting result of the orbital profile using the Wilson–Devinney code suggests that 2MASS J11201034-2201340 is a short-period A-type contact binary and the more massive component has a cool spot. The X-ray emission was first noted in observations made by Swift, and then further confirmed and characterized by an XMM-Newton observation. The X-ray spectrum can be described by a power law or thermal Bremsstrahlung. Unfortunately, we could not observe significant X-ray orbital modulation. Finally, according to the SED, this system is estimated to be 690 pc from Earth with a calculated X-ray intensity of (0.7-1.5)× {10}30 erg s‑1, which is in the expected range of an X-ray emitting contact binary.

  5. Discovery of an X-Ray-emitting Contact Binary System 2MASS J11201034-2201340

    NASA Astrophysics Data System (ADS)

    Hu, Chin-Ping; Yang, Ting-Chang; Chou, Yi; Liu, L.; Qian, S.-B.; Hui, C. Y.; Kong, Albert K. H.; Lin, L. C. C.; Tam, P. H. T.; Li, K. L.; Ngeow, Chow-Choong; Chen, W. P.; Ip, Wing-Huen

    2016-06-01

    We report the detection of orbital modulation, a model solution, and the X-ray properties of a newly discovered contact binary, Two Micron All Sky Survey (2MASS) J11201034-2201340. We serendipitously found this X-ray point source outside the error ellipse when searching for possible X-ray counterparts of γ-ray millisecond pulsars among the unidentified objects detected by the Fermi Gamma-ray Space Telescope. The optical counterpart of the X-ray source (unrelated to the γ-ray source) was then identified using archival databases. The long-term Catalina Real-Time Transient Survey detected a precise signal with a period of P=0.28876208(56) days. A follow-up observation made by the Super Light Telescope of Lulin Observatory revealed the binary nature of the object. Utilizing archived photometric data of multi-band surveys, we construct the spectral energy distribution (SED), which is well fit by a K2V spectral template. The fitting result of the orbital profile using the Wilson-Devinney code suggests that 2MASS J11201034-2201340 is a short-period A-type contact binary and the more massive component has a cool spot. The X-ray emission was first noted in observations made by Swift, and then further confirmed and characterized by an XMM-Newton observation. The X-ray spectrum can be described by a power law or thermal Bremsstrahlung. Unfortunately, we could not observe significant X-ray orbital modulation. Finally, according to the SED, this system is estimated to be 690 pc from Earth with a calculated X-ray intensity of (0.7-1.5)× {10}30 erg s-1, which is in the expected range of an X-ray emitting contact binary.

  6. The SDSS-2MASS-WISE 10-dimensional stellar colour locus

    NASA Astrophysics Data System (ADS)

    Davenport, James R. A.; Ivezić, Željko; Becker, Andrew C.; Ruan, John J.; Hunt-Walker, Nicholas M.; Covey, Kevin R.; Lewis, Alexia R.; AlSayyad, Yusra; Anderson, Lauren M.

    2014-06-01

    We present the fiducial main-sequence stellar locus traced by 10 photometric colours observed by Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey (2MASS), and Wide-field Infrared Survey Explorer (WISE). Median colours are determined using 1052 793 stars with r-band extinction less than 0.125. We use this locus to measure the dust extinction curve relative to the r band, which is consistent with previous measurements in the SDSS and 2MASS bands. The WISE band extinction coefficients are larger than predicted by standard extinction models. Using 13 lines of sight, we find variations in the extinction curve in H, Ks, and WISE bandpasses. Relative extinction decreases towards Galactic anticentre, in agreement with prior studies. Relative extinction increases with Galactic latitude, in contrast to previous observations. This indicates a universal mid-IR extinction law does not exist due to variations in dust grain size and chemistry with Galactocentric position. A preliminary search for outliers due to warm circumstellar dust is also presented, using stars with high signal-to-noise ratio in the W3 band. We find 199 such outliers, identified by excess emission in Ks - W3. Inspection of SDSS images for these outliers reveals a large number of contaminants due to nearby galaxies. Six sources appear to be genuine dust candidates, yielding a fraction of systems with infrared excess of 0.12 ± 0.05 per cent.

  7. A Galactic Plane relative extinction map from 2MASS

    NASA Astrophysics Data System (ADS)

    Froebrich, D.; Ray, T. P.; Murphy, G. C.; Scholz, A.

    2005-03-01

    We present three 14 400 square degree relative extinction maps of the Galactic Plane (|b| < 20°) obtained from 2MASS using accumulative star counts (Wolf diagrams). This method is independent of the colour of the stars and the variation of extinction with wavelength. Stars were counted in 3.5 × 3.5 boxes, every 20.1° × 1° surrounding fields were chosen for reference, hence the maps represent local extinction enhancements and ignore any contribution from the ISM or very large clouds. Data reduction was performed on a Beowulf-type cluster (in approximately 120 hours). Such a cluster is ideal for this type of work as areas of the sky can be independently processed in parallel. We studied how extinction depends on wavelength in all of the high extinction regions detected and within selected dark clouds. On average a power law opacity index (β) of 1.0 to 1.8 in the NIR was deduced. The index however differed significantly from region to region and even within individual dark clouds. That said, generally it was found to be constant, or to increase, with wavelength within a particular region.

  8. Carbapenems Versus Piperacillin-Tazobactam for Bloodstream Infections of Nonurinary Source Caused by Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae.

    PubMed

    Ofer-Friedman, Hadas; Shefler, Coral; Sharma, Sarit; Tirosh, Amit; Tal-Jasper, Ruthy; Kandipalli, Deepthi; Sharma, Shruti; Bathina, Pradeep; Kaplansky, Tamir; Maskit, Moran; Azouri, Tal; Lazarovitch, Tsilia; Zaidenstein, Ronit; Kaye, Keith S; Marchaim, Dror

    2015-08-01

    A recent, frequently quoted study has suggested that for bloodstream infections (BSIs) due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL) Escherichia coli, treatment with β-lactam/β-lactamase inhibitors (BLBLIs) might be equivalent to treatment with carbapenems. However, the majority of BSIs originate from the urinary tract. A multicenter, multinational efficacy analysis was conducted from 2010 to 2012 to compare outcomes of patients with non-urinary ESBL BSIs who received a carbapenem (69 patients) vs those treated with piperacillin-tazobactam (10 patients). In multivariate analysis, therapy with piperacillin-tazobactam was associated with increased 90-day mortality (adjusted odds ratio, 7.9, P=.03). For ESBL BSIs of a non-urinary origin, carbapenems should be considered a superior treatment to BLBLIs.

  9. Using the 2-MASS photometric redshift survey to optimize LIGO follow-up observations

    NASA Astrophysics Data System (ADS)

    Antolini, Elisa; Heyl, Jeremy S.

    2016-10-01

    The initial discovery of Laser Interferometer Gravitational-Wave Observatory (LIGO) on 2015 September 14 was the inspiral merger and ring-down of the black hole binary at a distance of about 500 Mpc or a redshift of about 0.1. The search for electromagnetic counterparts for the inspiral of binary black holes is impeded by coarse initial source localizations and a lack of a compelling model for the counterpart; therefore, rapid electromagnetic follow-up is required to understand the astrophysical context of these sources. Because astrophysical sources of gravitational radiation are likely to reside in galaxies, it would make sense to search first in regions where the LIGO-Virgo probability is large and where the density of galaxies is large as well. Under the assumption that the probability of a gravitational-wave event from a given region of space is proportional to the density of galaxies within the probed volume, one can calculate an improved localization of the position of the source simply by multiplying the LIGO-Virgo skymap by the density of galaxies in the range of redshifts. We propose using the 2-MASS photometric redshift galaxy catalogue for this purpose and demonstrate that using it can dramatically reduce the search region for electromagnetic counterparts.

  10. Local systematic differences in proper motions derived from 2MASS positions

    NASA Astrophysics Data System (ADS)

    Bustos Fierro, I. H.; Calderón, J. H.

    2016-04-01

    We want to draw attention to local systematic differences that appear in the proper motions derived from 2MASS positions when they are compared with other astrometric catalogs such as UCAC4, SPM4 and USNO-B1. It is shown that 2MASS effectively causes these systematic effects in the proper motions of PPMXL and URAT1. Also it is shown that using 2MASS positions rectified with respect to UCAC4 the systematic pattern of the proper motions of URAT1 is eliminated. Therefore, we propose the use of rectified 2MASS positions in order to derive proper motions free from 2MASS systematics.

  11. Extended Characterization of the Common-Source and Common-Gate Amplifiers using a Metal-Ferroelectric-Semiconductor Field Effect Transistor

    NASA Technical Reports Server (NTRS)

    Hunt, Mitchell; Sayyah, Rana; Mitchell, Cody; Laws, Crystal; MacLeod, Todd C.; Ho, Fat D.

    2013-01-01

    Collected data for both common-source and common-gate amplifiers is presented in this paper. Characterizations of the two amplifier circuits using metal-ferroelectric-semiconductor field effect transistors (MFSFETs) are developed with wider input frequency ranges and varying device sizes compared to earlier characterizations. The effects of the ferroelectric layer's capacitance and variation load, quiescent point, or input signal on each circuit are discussed. Comparisons between the MFSFET and MOSFET circuit operation and performance are discussed at length as well as applications and advantages for the MFSFETs.

  12. The Use of Source-Sink and Doublet Distributions Extended to the Solution of Boundary-Value Problems in Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Heaslet, Max A; Lomax, Harvard

    1948-01-01

    A direct analogy is established between the use of source-sink and doublet distributions in the solution of specific boundary-value problems in subsonic wing theory and the corresponding problems in supersonic theory. The correct concept of the "finite part" of an integral is introduced and used in the calculation of the improper integrals associated with supersonic doublet distributions. The general equations developed are shown to include several previously published results and particular examples are given for the loading on rolling and pitching triangular wings with supersonic leading edges.

  13. Monte Carlo analysis of the influence of germanium dead layer thickness on the HPGe gamma detector experimental efficiency measured by use of extended sources.

    PubMed

    Chham, E; García, F Piñero; El Bardouni, T; Ferro-García, M Angeles; Azahra, M; Benaalilou, K; Krikiz, M; Elyaakoubi, H; El Bakkali, J; Kaddour, M

    2014-09-22

    We have carried out a study to figure out the influence of crystal inactive-layer thickness on gamma spectra measured by an HPGe detector. The thickness of this dead layer (DL) is not known (no information about it was delivered by the manufacturer) due to the existence of a transition zone where photons are increasingly absorbed. To perform this analyses a virtual model of a Canberra HPGe detector was produced with the aid of MCNPX 2.7 code. The main objective of this work is to produce an optimal modeling for our GPGe detector. To this end, the study included the analysis of the total inactive germanium layer thickness and the active volume that are needed in order to obtain the smallest discrepancy between calculated and experimental efficiencies. Calculations and measurements were performed for all of the radionuclides included in a standard calibration gamma cocktail solution. Different geometry sources were used: a Marinelli and two other new sources represented as S(1) and S(2). The former was used for the determination of the active volume, whereas the two latter were used for the determination of the face and lateral DL, respectively. The model was validated by comparing calculated and experimental full energy peak efficiencies in the 50-1900keV energy range. the results show that the insertion of the DL parameter in the modeling is absolutely essential to reproduce the experimental results, and that the thickness of this DL varies from one position to the other on the detector surface.

  14. High K-alpha X-ray Conversion Efficiency From Extended Source Gas Jet Targets Irradiated by Ultra Short Laser Pulses

    SciTech Connect

    Kugland, N L; Constantin, C; Collette, A; Dewald, E; Froula, D; Glenzer, S H; Kritcher, A; Neumayer, P; Ross, J S; Niemann, C

    2007-11-01

    The absolute laser conversion efficiency to K{sub {alpha}}-like inner shell x-rays (integrated from K{sub {alpha}} to K{sub {beta}}) is observed to be an order of magnitude higher in argon gas jets than in solid targets due to enhanced emission from higher ionization stages following ultra short pulse laser irradiation. Excluding the higher ionization stages, the conversion efficiency to near-cold K{sub {alpha}} is the same in gas jets as in solid targets. These results demonstrate that gas jet targets are bright, high conversion efficiency, high repetition rate, debris-free multi-keV x-ray sources for spectrally resolved scattering and backlighting of rapidly evolving dense matter.

  15. INFORMATION ON THE MILKY WAY FROM THE 2MASS ALL SKY STAR COUNT: BIMODAL COLOR DISTRIBUTIONS

    SciTech Connect

    Chang, Chan-Kao; Lai, Shao-Yu; Peng, Ting-Hung; Ko, Chung-Ming E-mail: cmko@astro.ncu.edu.tw

    2012-11-10

    The J - K{sub s} color distributions (CDs) with a bin size of 0.05 mag has been carried out for the entire Milky Way using the Two Micron All Sky Survey Point Source Catalog (2MASS PSC). The CDs are bimodal, with a red peak at 0.8 < J - K{sub s} < 0.85 and a blue peak at 0.3 < J - K{sub s} < 0.4. The colors of the red peak are more or less the same for the whole sky, but those of the blue peak depend on Galactic latitude (J - K{sub s} {approx} 0.35 at low Galactic latitudes and 0.35 < J - K{sub s} < 0.4 for other sky areas). The blue peak dominates the bimodal CDs at low Galactic latitudes and becomes comparable with the red peak in other sky regions. In order to explain the bimodal distribution and the global trend shown by the all-sky 2MASS CDs, we assemble an empirical Hertzsprung-Russell (H-R) diagram, which is composed of observational-based near-infrared H-R diagrams and color-magnitude diagrams, and incorporate a Milky Way model. In the empirical H-R diagram, the main-sequence turn-off for stars in the thin disk is relatively bluer, (J - K{sub s} ){sub 0} = 0.31, compared with that of the thick disk which is (J - K{sub s} ){sub 0} = 0.39. The age of the thin/thick disk is roughly estimated to be around 4-5/8-9 Gyr according to the color-age relation of the main-sequence turn-off. In general, the 2MASS CDs can be treated as a tool to measure the age of the stellar population of the Milky Way in a statistical manner and to our knowledge it is the first attempt to do so.

  16. Extended Wordsearches in Chemistry

    NASA Astrophysics Data System (ADS)

    Cotton, Simon

    1998-04-01

    Students can be encouraged to develop their factual knowledge by use of puzzles. One strategy described here is the extended wordsearch, where the wordsearch element generates a number of words or phrases from which the answers to a series of questions are selected. The wordsearch can be generated with the aid of computer programs, though in order to make them suitable for students with dyslexia or other learning difficulties, a simpler form is more appropriate. These problems can be employed in a variety of contexts, for example, as topic tests and classroom end-of-lesson fillers. An example is provided in the area of calcium chemistry. Sources of suitable software are listed.

  17. A SEARCH FOR HIGH PROPER MOTION T DWARFS WITH Pan-STARRS1 + 2MASS + WISE

    SciTech Connect

    Liu, Michael C.; Deacon, Niall R.; Magnier, Eugene A.; Aller, Kimberly M.; Bowler, Brendan P.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Dupuy, Trent J.; Redstone, Joshua; Goldman, Bertrand; Price, P. A.

    2011-10-20

    We have searched {approx}8200 deg{sup 2} for high proper motion ({approx}0.''5-2.''7 year{sup -1}) T dwarfs by combining first-epoch data from the Pan-STARRS1 (PS1) 3{pi} Survey, the Two Micron All Sky Survey (2MASS) All-Sky Point Source Catalog, and the WISE Preliminary Data Release. We identified two high proper motion objects with the very red (W1 - W2) colors characteristic of T dwarfs, one being the known T7.5 dwarf GJ 570D. Near-IR spectroscopy of the other object (PSO J043.5395+02.3995 {identical_to} WISEP J025409.45+022359.1) reveals a spectral type of T8, leading to a photometric distance of 7.2 {+-} 0.7 pc. The 2.''56 year{sup -1} proper motion of PSO J043.5+02 is the second highest among field T dwarfs, corresponding to a tangential velocity of 87 {+-} 8 km s{sup -1}. According to the Besancon galaxy model, this velocity indicates that its galactic membership is probably in the thin disk, with the thick disk an unlikely possibility. Such membership is in accord with the near-IR spectrum, which points to a surface gravity (age) and metallicity typical of the field population. We combine 2MASS, Sloan Digital Sky Survey, WISE, and PS1 astrometry to derive a preliminary parallax of 171 {+-} 45 mas (5.8{sup +2.0} {sub -1.2} pc), the first such measurement using PS1 data. The proximity and brightness of PSO J043.5+02 will facilitate future characterization of its atmosphere, variability, multiplicity, distance, and kinematics. The modest number of candidates from our search suggests that the immediate ({approx}10 pc) solar neighborhood does not contain a large reservoir of undiscovered T dwarfs earlier than about T8.

  18. Long Period Variables in the LMC: Results from MACHO and 2Mass

    SciTech Connect

    Fraser, O J; Cook, K H; Keller, S C; Hawley, S L

    2004-07-19

    We use the eight year light curve database from the MACHO (MAssive Compact Halo Objects) project together with infrared colors and magnitudes from 2MASS (the Two Micron All Sky Survey) to identify a sample of 22,000 long period variables in the Large Magellanic Cloud (referred to hereafter as LMC LPVs). A period luminosity diagram of these stars reveals six well defined sequences, in substantial agreement with previous analyses of samples from OGLE (Optical Gravitational Lensing Experiment). In our analysis we identify analogues to galactic LPVs in the LMC LPV sample. We find that carbon dominated AGB stars populate only two of the sequences, one of which includes the Mira variables. The high luminosity end of the same two sequences are also the location of the only stars with J K{sub s} > 2, indicating that they are enshrouded in dust. The unknown mechanism that produces the variability of the last sequence--those stars with long secondary periods--produces different morphology in the period luminosity diagram than what is seen in the first four sequences, which are thought to be caused by pulsation. In particular, the last sequence extends to lower luminosity RGB stars and the luminosity function does not peak among the AGB stars. We point out several features which will constrain new models of the period luminosity sequences.

  19. EX56a study of extended X-ray emission around isolated galaxies EX56b identification and spectra of bright X-ray sources at high galactic latitude

    NASA Technical Reports Server (NTRS)

    Schwartz, Daniel A.

    1987-01-01

    The EXOSAT observations confirmed the identification and extended nature of PKS 2345-35. It gave a good 2 to 10 keV X-ray spectrum and a detailed spatial profile indicating asymmetry of the structure. In the high galactic latitidue investigation, the BL Lac object identified with the HEAO-1 source 1430+423 was detected, and the first X-ray spectrum was obtained. Several simulataneous observations of H0323+022 were obtained over a broad range of electromagnetic spectrum. Studies of luminous active galactic nuclei have given significant information on the spectrum of the quasar PKS 0558-504. In a study of Southern sky cataclysmic variables, the EXOSAT was used to determine the X-ray spectrum and search for periodicities in two objects. Studies of complete identifications have revealed that X-ray sources in two high galactic latitude fields are stars, and therefore are to be excluded from the Piccinotti extragalactic sample. Only one Piccinotti source remains to be identified.

  20. Multi-wavelength Characterization of Stellar Flares on Low-mass Stars Using SDSS and 2MASS Time-domain Surveys

    NASA Astrophysics Data System (ADS)

    Davenport, James R. A.; Becker, Andrew C.; Kowalski, Adam F.; Hawley, Suzanne L.; Schmidt, Sarah J.; Hilton, Eric J.; Sesar, Branimir; Cutri, Roc

    2012-03-01

    We present the first rates of flares from M dwarf stars in both red optical and near-infrared (NIR) filters. We have studied ~50,000 M dwarfs from the Sloan Digital Sky Survey (SDSS) Stripe 82 area and 1321 M dwarfs from the Two Micron All Sky Survey (2MASS) Calibration Scan Point Source Working Database that overlap SDSS imaging fields. We assign photometric spectral types from M0 to M6 using (r - i) and (i - z) colors for every star in our sample. Stripe 82 stars each have 50-100 epochs of data, while 2MASS Calibration stars have ~1900 epochs. From these data we estimate the observed rates and theoretical detection thresholds for flares in eight photometric bands as a function of spectral type. Optical flare rates are found to be in agreement with previous studies, while the frequency per hour of NIR flare detections is found to be more than two orders of magnitude lower. An excess of small-amplitude flux increases in all bands exhibits a power-law distribution, which we interpret as the result of flares below our detection thresholds. In order to investigate the recovery efficiency for flares in each filter, we extend a two-component flare model into the NIR. Quiescent M0-M6 spectral templates were used with the model to predict the photometric response of flares from u to Ks . We determine that red optical filters are sensitive to flares with u-band amplitudes gsim2 mag, and NIR filters to flares with Δu gsim 4.5 mag. Our model predicts that M0 stars have the best color contrast for J-band detections, but M4-M6 stars should yield the highest rate of NIR flares with amplitudes of ΔJ >= 0.01 mag. Characterizing flare rates and photometric variations at longer wavelengths is important for predicting the signatures of M dwarf variability in next-generation surveys, and we discuss their impact on surveys such as the Large Synoptic Survey Telescope.

  1. MULTI-WAVELENGTH CHARACTERIZATION OF STELLAR FLARES ON LOW-MASS STARS USING SDSS AND 2MASS TIME-DOMAIN SURVEYS

    SciTech Connect

    Davenport, James R. A.; Becker, Andrew C.; Kowalski, Adam F.; Hawley, Suzanne L.; Schmidt, Sarah J.; Hilton, Eric J.; Sesar, Branimir; Cutri, Roc

    2012-03-20

    We present the first rates of flares from M dwarf stars in both red optical and near-infrared (NIR) filters. We have studied {approx}50,000 M dwarfs from the Sloan Digital Sky Survey (SDSS) Stripe 82 area and 1321 M dwarfs from the Two Micron All Sky Survey (2MASS) Calibration Scan Point Source Working Database that overlap SDSS imaging fields. We assign photometric spectral types from M0 to M6 using (r - i) and (i - z) colors for every star in our sample. Stripe 82 stars each have 50-100 epochs of data, while 2MASS Calibration stars have {approx}1900 epochs. From these data we estimate the observed rates and theoretical detection thresholds for flares in eight photometric bands as a function of spectral type. Optical flare rates are found to be in agreement with previous studies, while the frequency per hour of NIR flare detections is found to be more than two orders of magnitude lower. An excess of small-amplitude flux increases in all bands exhibits a power-law distribution, which we interpret as the result of flares below our detection thresholds. In order to investigate the recovery efficiency for flares in each filter, we extend a two-component flare model into the NIR. Quiescent M0-M6 spectral templates were used with the model to predict the photometric response of flares from u to K{sub s} . We determine that red optical filters are sensitive to flares with u-band amplitudes {approx}>2 mag, and NIR filters to flares with {Delta}u {approx}> 4.5 mag. Our model predicts that M0 stars have the best color contrast for J-band detections, but M4-M6 stars should yield the highest rate of NIR flares with amplitudes of {Delta}J {>=} 0.01 mag. Characterizing flare rates and photometric variations at longer wavelengths is important for predicting the signatures of M dwarf variability in next-generation surveys, and we discuss their impact on surveys such as the Large Synoptic Survey Telescope.

  2. EVIDENCE AGAINST AN EDGE-ON DISK AROUND THE EXTRASOLAR PLANET, 2MASS 1207 b AND A NEW THICK-CLOUD EXPLANATION FOR ITS UNDERLUMINOSITY

    SciTech Connect

    Skemer, Andrew J.; Close, Laird M.; Szucs, Laszlo; Apai, Daniel; Pascucci, Ilaria; Biller, Beth A.

    2011-05-10

    Since the discovery of the first directly imaged, planetary-mass object, 2MASS 1207 b, several works have sought to explain a disparity between its observed temperature and luminosity. Given its known age, distance, and spectral type, 2MASS 1207 b is underluminous by a factor of {approx}10 ({approx}2.5 mag) when compared to standard models of brown-dwarf/giant-planet evolution. In this paper, we study three possible sources of 2MASS 1207 b's underluminosity. First, we investigate Mohanty et al.'s hypothesis that a near edge-on disk, comprising large, gray-extincting grains, might be responsible for 2MASS 1207 b's underluminosity. After radiative transfer modeling, we conclude that the hypothesis is unlikely due to the lack of variability seen in multi-epoch photometry and unnecessary due to the increasing sample of underluminous brown dwarfs/giant exoplanets that cannot be explained by an edge-on disk. Next, we test the analogous possibility that a spherical shell of dust could explain 2MASS 1207 b's underluminosity. Models containing enough dust to create {approx}2.5 mag of extinction, placed at reasonable radii, are ruled out by our new Gemini/T-ReCS 8.7 {mu}m photometric upper limit for 2MASS 1207 b. Finally, we investigate the possibility that 2MASS 1207 b is intrinsically cooler than the commonly used AMES-DUSTY fits to its spectrum, and thus it is not, in fact, underluminous. New, thick-cloud model grids by Madhusudhan et al. fit 2MASS 1207 b's 1-10 {mu}m spectral energy distribution well, but they do not quite fit its near-infrared spectrum. However, we suggest that with some 'tuning', they might be capable of simultaneously reproducing 2MASS 1207 b's spectral shape and luminosity. In this case, the whole class of young, underluminous brown dwarfs/giant exoplanets might be explained by atmospheres that are able to suspend thick, dusty clouds in their photospheres at temperatures lower than field brown dwarfs.

  3. A method for local rectification of 2MASS positions with UCAC4

    NASA Astrophysics Data System (ADS)

    Bustos Fierro, I. H.; Calderón, J. H.

    2016-04-01

    We propose to locally rectify 2MASS with respect to UCAC4 in order to diminish the systematic differences between these catalogs. We develop a rectification method that starts computing the weighted mean differences 2MASS-UCAC4 on a regular grid on the sky. The corrections that are later applied to 2MASS positions are obtained by a spline interpolation of the mean values calculated on the grid. The method is tested in four 3° × 3° fields in the ecliptical zone; after rectification in all of them the systematic differences are reduced well below the random differences. The 2MASS catalog rectified with the proposed method can be regarded as an extension of UCAC4 for astrometry, with an accuracy of around 90 mas in the positions, and with negligible systematic errors, for instance for the astrometric reduction of small field CCD images.

  4. RELIABLE IDENTIFICATIONS OF ACTIVE GALACTIC NUCLEI FROM THE WISE, 2MASS, AND ROSAT ALL-SKY SURVEYS

    SciTech Connect

    Edelson, R.; Malkan, M.

    2012-05-20

    We have developed the ''S{sub IX}'' statistic to identify bright, highly likely active galactic nucleus (AGN) candidates solely on the basis of Wide-field Infrared Survey Explorer (WISE), Two Micron All-Sky Survey (2MASS), and ROSAT all-sky survey (RASS) data. This statistic was optimized with data from the preliminary WISE survey and the Sloan Digital Sky Survey, and tested with Lick 3 m Kast spectroscopy. We find that sources with S{sub IX} < 0 have a {approx}>95% likelihood of being an AGN (defined in this paper as a Seyfert 1, quasar, or blazar). This statistic was then applied to the full WISE/2MASS/RASS dataset, including the final WISE data release, to yield the ''W2R'' sample of 4316 sources with S{sub IX} < 0. Only 2209 of these sources are currently in the Veron-Cetty and Veron (VCV) catalog of spectroscopically confirmed AGNs, indicating that the W2R sample contains nearly 2000 new, relatively bright (J {approx}< 16) AGNs. We utilize the W2R sample to quantify biases and incompleteness in the VCV catalog. We find that it is highly complete for bright (J < 14), northern AGNs, but the completeness drops below 50% for fainter, southern samples and for sources near the Galactic plane. This approach also led to the spectroscopic identification of 10 new AGNs in the Kepler field, more than doubling the number of AGNs being monitored by Kepler. The W2R sample contains better than 1 bright AGN every 10 deg{sup 2}, permitting construction of AGN samples in any sufficiently large region of sky.

  5. Stars with Extended Atmospheres

    NASA Astrophysics Data System (ADS)

    Sterken, C.

    2002-12-01

    This Workshop consisted of a full-day meeting of the Working Group "Sterren met Uitgebreide Atmosferen" (SUA, Working Group Stars with Extended Atmospheres), a discussion group founded in 1979 by Kees de Jager, Karel van der Hucht and Pik Sin The. This loose association of astronomers and astronomy students working in the Dutch-speaking part of the Low Countries (The Netherlands and Flanders) organised at regular intervals one-day meetings at the Universities of Utrecht, Leiden, Amsterdam and Brussels. These meetings consisted of the presentation of scientific results by junior as well as senior members of the group, and by discussions between the participants. As such, the SUA meetings became a forum for the exchange of ideas, and for asking questions and advice in an informal atmosphere. Kees de Jager has been chairman of the WG SUA from the beginning in 1979 till today, as the leading source of inspiration. At the occasion of Prof. Kees de Jager's 80th birthday, we decided to collect the presented talks in written form as a Festschrift in honour of this well-respected and much beloved scientist, teacher and friend. The first three papers deal with the personality of Kees de Jager, more specifically with his role as a supervisor and mentor of young researchers and as a catalyst in the research work of his colleagues. And also about his remarkable role in the establishment of astronomy education and research at the University of Brussels. The next presentation is a very detailed review of solar research, a field in which Cees was prominently active for many years. Then follow several papers dealing with stars about which Kees is a true expert: massive stars and extended atmospheres.

  6. SPATIALLY RESOLVED OBSERVATIONS OF THE BIPOLAR OPTICAL OUTFLOW FROM THE BROWN DWARF 2MASS J12073347-3932540

    SciTech Connect

    Whelan, E. T.; Ray, T. P.; Comeron, F.; Bacciotti, F.; Kavanagh, P. J.

    2012-12-20

    Studies of brown dwarf (BD) outflows provide information pertinent to questions on BD formation, as well as allowing outflow mechanisms to be investigated at the lowest masses. Here new observations of the bipolar outflow from the 24 M{sub JUP} BD 2MASS J12073347-3932540 are presented. The outflow was originally identified through the spectro-astrometric analysis of the [O I]{lambda}6300 emission line. Follow-up observations consisting of spectra and [S II], R-band and I-band images were obtained. The new spectra confirm the original results and are used to constrain the outflow position angle (P.A.) at {approx}65 Degree-Sign . The [O I]{lambda}6300 emission line region is spatially resolved and the outflow is detected in the [S II] images. The detection is firstly in the form of an elongation of the point-spread function (PSF) along the direction of the outflow P.A. Four faint knot-like features (labeled A-D) are also observed to the southwest of 2MASS J12073347-3932540 along the same P.A. suggested by the spectra and the elongation in the PSF. Interestingly, D, the feature furthest from the source, is bow shaped with the apex pointing away from 2MASS J12073347-3932540. A color-color analysis allows us to conclude that at least feature D is part of the outflow under investigation while A is likely a star or galaxy. Follow-up observations are needed to confirm the origin of B and C. This is a first for a BD, as BD optical outflows have to date only been detected using spectro-astrometry. This result also demonstrates for the first time that BD outflows can be collimated and episodic.

  7. Geometry of the LMC Disk: Results from MACHO and 2MASS

    SciTech Connect

    Nikolaev, S; Drake, A; Keller, S; Cook, K; Dalal, N; Griest, K; Welch, D; Kanbur, S

    2003-11-04

    We have cross-correlated MACHO LMC Cepheids with 2MASS Second Incremental Release Catalog. The resulting database is considerably larger than the set of OGLE Cepheids in the LMC bar, and has significantly better areal coverage, allowing more accurate determination of LMC geometry. Random-phase correction is applied to 2MASS J, H, and Ks magnitudes, using the knowledge of V-band light curve and the ephemeris of 2MASS observations, to produce mean magnitudes. The improvement of phase-corrected PL relations over random-phase PL relations is clearly demonstrated. Reddening is estimated for each star individually, further improving the accuracy of the method. The orientation parameters of the LMC are derived by a Maximum Likelihood approach which solves for viewing angles and PL coefficients simultaneously, providing an unbiased estimation. The results of the analysis are used to place limits on warping of the LMC disk. Implications for the microlensing optical depth are also discussed.

  8. On the Nature of the Unique Hα-emitting T Dwarf 2MASS J12373919+6526148

    NASA Astrophysics Data System (ADS)

    Liebert, James; Burgasser, Adam J.

    2007-01-01

    We explore and discount the hypothesis that the strong, continual Hα-emitting T dwarf 2MASS J12373919+6526148 can be explained as a young, low-gravity, very low mass brown dwarf. The source is already known to have a marginally fainter absolute magnitude than similar T dwarfs with trigonometric parallax measurements and has a tangential velocity consistent with old disk kinematics. Applying the technique of Burgasser et al. on new near-infrared spectroscopy for this source, estimates of its Teff, logg, and metallicity ([M/H]) are obtained. 2M 1237+6526 has a Teff~800-850 K. If [M/H] is solar, logg is as high as ~5.5 (cgs) and this source is older than 10 Gyr. We find a more plausible scenario to be a modestly subsolar metallicity ([M/H]=-0.2) and moderate logg~5.0, implying an age older than 2 Gyr and a mass greater than 0.035 Msolar. The alternative explanation of the unique emission of this source, involving an interacting, close, double degenerate system, should be investigated further. Indeed, there is some evidence of a Teff<500 K companion to 2M 1237+6526 on the basis of a possible Spitzer IRAC [3.6]-[4.5] color excess. This excess may, however, be caused by a subsolar metallicity.

  9. The SW Sextantis-type star 2MASS J01074282+4845188: an unusual bright accretion disk with non-steady emission and a hot white dwarf

    NASA Astrophysics Data System (ADS)

    Khruzina, T.; Dimitrov, D.; Kjurkchieva, D.

    2013-03-01

    Context. Cataclysmic variables (CVs) present a short evolutional stage of binary systems. The nova-like stars are rare objects, especially those with eclipses (only several tens). But precisely these allow to determine the global parameters of their configurations and to learn more about the late stage of stellar evolution. Aims: The light curve solution allows one to determine the global parameters of the newly discovered nova-like eclipsing star 2MASS J01074282+4845188 and to estimate the contribution of the different light sources. Methods: We present new photometric and spectral observations of 2MASS J01074282+4845188. To obtain a light curve solution we used a model of a nova-like star whose emission sources are a white dwarf surrounded by an accretion disk, a secondary star filling its Roche lobe, a hot spot and a hot line. The obtained global parameters are compared with those of the eclipsing nova-like UX UMa. Results: 2MASS J01074282+4845188 shows the deepest permanent eclipse among the known nova-like stars. It is reproduced by covering the very bright accretion disk by the secondary component. The luminosity of the disk is much bigger than that of the rest light sources. The determined high temperature of the disk is typical for that observed during the outbursts of CVs. The primary of 2MASS J01074282+4845188 is one of the hottest white dwarfs in CVs. The temperature of 5090 K of its secondary is also quite high and more appropriate for a long-period SW Sex star. It might be explained by the intense heating from the hot white dwarf and the hot accretion disk of the target. Conclusions: The high mass accretion rate Ṁ = 8 × 10-9 M⊙ yr-1, the broad and single-peaked Hα emission profile, and the presence of an S-wave are sure signs for the SW Sex classification of 2MASS J01074282+4845188. The obtained flat temperature distribution along the disk radius as well as the deviation of the energy distribution from the black-body law are evidence of the non

  10. Extending the extended V-Y flap.

    PubMed

    Prowse, Phoebe; Morton, Jonathan

    2012-06-01

    This case report demonstrates a modification of the so-called 'Extended V-Y Flap' used to simultaneously reconstruct a defect involving the upper lip, floor of nose and alar rim following tumour excision. We hope that this case serves as a reminder of the versatility of the V-Y flap in the nasolabial region, and its considerable capacity for augmentation. PMID:22018837

  11. 2MASS J06164006-6407194: THE FIRST OUTER HALO L SUBDWARF

    SciTech Connect

    Cushing, Michael C.; Looper, Dagny; Burgasser, Adam J.; Sanderson, Robyn E.; Kirkpatrick, J. Davy; Cruz, Kelle L.; Sweet, Anne

    2009-05-01

    We present the serendipitous discovery of an L subdwarf in the Two Micron All Sky Survey (2MASS) J06164006-6407194, in a search of the 2MASS for T dwarfs. Its spectrum exhibits features indicative of both a cool and metal poor atmosphere including a heavily pressure-broadened K I resonant doublet, Cs I and Rb I lines, molecular bands of CaH, TiO, CrH, FeH, and H{sub 2}O, and enhanced collision induced absorption of H{sub 2}. We assign 2MASS J0616-6407 a spectral type of sdL5 based on a comparison of its red optical spectrum to that of near solar-metallicity L dwarfs. Its high proper motion ({mu} = 1.''405 {+-} 0.008 yr{sup -1}), large radial velocity (V {sub rad} = 454 {+-} 15 km s{sup -1}), estimated u, v, w velocities (94, -573, 125) km s{sup -1} and Galactic orbit with an apogalacticon at {approx}29 kpc are indicative of membership in the outer halo making 2MASS J0616-6407 the first ultracool member of this population.

  12. Star-galaxy separation strategies for WISE-2MASS all-sky infrared galaxy catalogues

    NASA Astrophysics Data System (ADS)

    Kovács, András; Szapudi, István

    2015-04-01

    We combine photometric information of the Wide-Field Infrared Survey Explorer (WISE) and Two Micron All Sky Survey (2MASS) all-sky infrared data bases, and demonstrate how to produce clean and complete galaxy catalogues for future analyses. Adding 2MASS colours to WISE photometry improves star-galaxy separation efficiency substantially at the expense of losing a small fraction of the galaxies. We find that 93 per cent of the WISE objects within W1 < 15.2 mag have a 2MASS match, and that a class of supervised machine learning algorithms, support vector machines (SVM), are efficient classifiers of objects in our multicolour data set. We constructed a training set from the Sloan Digital Sky Survey PhotoObj table with known star-galaxy separation, and determined redshift distribution of our sample from the Galaxy and Mass Assembly spectroscopic survey. Varying the combination of photometric parameters input into our algorithm we show that W1WISE - J2MASS is a simple and effective star-galaxy separator, capable of producing results comparable to the multidimensional SVM classification. We present a detailed description of our star-galaxy separation methods, and characterize the robustness of our tools in terms of contamination, completeness, and accuracy. We explore systematics of the full sky WISE-2MASS galaxy map, such as contamination from moon glow. We show that the homogeneity of the full sky galaxy map is improved by an additional J2MASS < 16.5 mag flux limit. The all-sky galaxy catalogue we present in this paper covers 21 200 deg2 with dusty regions masked out, and has an estimated stellar contamination of 1.2 per cent and completeness of 70.1 per cent among 2.4 million galaxies with zmed ≈ 0.14. WISE-2MASS galaxy maps with well controlled stellar contamination will be useful for spatial statistical analyses, including cross-correlations with other cosmological random fields, such as the cosmic microwave background. The same techniques also yield a

  13. Functional Extended Redundancy Analysis

    ERIC Educational Resources Information Center

    Hwang, Heungsun; Suk, Hye Won; Lee, Jang-Han; Moskowitz, D. S.; Lim, Jooseop

    2012-01-01

    We propose a functional version of extended redundancy analysis that examines directional relationships among several sets of multivariate variables. As in extended redundancy analysis, the proposed method posits that a weighed composite of each set of exogenous variables influences a set of endogenous variables. It further considers endogenous…

  14. Extended or Restricted Childhood?

    ERIC Educational Resources Information Center

    Richards, Colin

    2005-01-01

    This article discusses the Government's proposals for "extended" primary schools, an important element in the recently-published five-year plan for education. The author expresses concern that extended primary schools will not provide a variety of experiences, including "play" experiences for young children.

  15. Extended conformal field theories

    NASA Astrophysics Data System (ADS)

    Taormina, Anne

    1990-08-01

    Some extended conformal field theories are briefly reviewed. They illustrate how non minimal models of the Virasoro algebra (c≥1) can become minimal with respect to a larger algebra. The accent is put on N-extended superconformal algebras, which are relevant in superstring compactification.

  16. Extending mine life

    SciTech Connect

    Not Available

    1984-06-01

    Mine layouts, new machines and techniques, research into problem areas of ground control and so on, are highlighted in this report on extending mine life. The main resources taken into account are coal mining, uranium mining, molybdenum and gold mining.

  17. Mapping the inner stellar halo of the Milky Way from 2MASS and SDSS-III/APOGEE survey

    NASA Astrophysics Data System (ADS)

    Fernández-Trincado, J. G.; Robin, A. C.; Reylé, C.

    2015-12-01

    The Besançon Galaxy model was used to compare the infrared colour distribution of synthetic stars with those from 2MASS observations taking the selection function of the data into account, in order to study the shape of the stellar halo of the Milky Way, with complemetary spectroscopic data from SDSS-III/APOGEE survey. Furthermore, we compared the generated mock metallicity distribution of the Besançon Galaxy model, to the intrinsic metallicity distribution with reliable stellar parameters from the APOGEE Stellar Parameters and Chemical Abundances Pipeline (ASPCAP). The comparison was carried accross a large volume of the inner part of the Galaxy, revealing that a metal-poor population, [M/H]<-1.2 dex, could fill an extended component of the inner galactic halo. With this data set, we are able to model a more realistic mass density distribution of the stellar halo component of the Milky Way, assuming a six-parameters double power-law model, and reconstruct the behaviour of the rotation curve in the inner part of the Galaxy.

  18. Exposing Sgr tidal debris behind the Galactic disc with M giants selected in WISE∩2MASS

    NASA Astrophysics Data System (ADS)

    Koposov, S. E.; Belokurov, V.; Zucker, D. B.; Lewis, G. F.; Ibata, R. A.; Olszewski, E. W.; López-Sánchez, Á. R.; Hyde, E. A.

    2015-01-01

    We show that a combination of infrared photometry from WISE and 2MASS surveys can yield highly pure samples of M giant stars. We take advantage of the new WISE∩2MASS M giant selection to trace the Sagittarius (Sgr) trailing tail behind the Galactic disc in the direction of the anticentre. The M giant candidates selected via broad-band photometry are confirmed spectroscopically using AAOmega on the Anglo-Australian Telescope in three fields around the extremity of the Sgr trailing tail in the Southern Galactic hemisphere. We demonstrate that at the Sgr longitude tilde{Λ }_{{⊙}} = 204°, the line-of-sight velocities of the trailing tail starts to deviate from the track of the Law & Majewski model, confirming the prediction of Belokurov et al. This discovery serves to substantiate the measurement of low differential orbital precession of the Sgr stream which in turn may imply diminished dark matter content within 100 kpc.

  19. Extended lifetime railgap switch

    SciTech Connect

    Cohn, D.B.; Mendoza, P.J.

    1988-02-02

    In a railgap switch of the type having an elongate blade electrode made of conductive material, an elongate housing made of insulating material for supporting the blade electrode and plate electrode in opposed relation extending in the same direction with the blade centered over the plate and separated therefrom by a gap, and a gas filling the housing and the gap, the gas being selected to breakdown and switch from a highly insulative state to a highly conductive state upon application of a high voltage across the blade and plate electrodes, the improvement is described comprising: forming the blade with laterally extending transverse wing portions at the edge of the blade and adjacent the gap so as to extend in spaced parallel relation to the surface of the plate, the blade generally following the contour thereof to form an inverted T-shape structure with the wing portions extending transversely of the elongate dimension of the blade. The wing portions terminating in a pair of spaced parallel edges extending along the elongate direction of the blade to thereby create two spaced elongate edges along which arcs form serving to divide the erosion effects of discharge between them, the current through each edge being one-half of that in single-edge devices with ablation wear reduced accordingly to give significantly larger switch lifetime. The blade and wing portions limiting ablation erosion of the edges in a direction generally align with the plate contour so that the edge-to-plate separation remains substantially constant.

  20. Extending quantum mechanics entails extending special relativity

    NASA Astrophysics Data System (ADS)

    Aravinda, S.; Srikanth, R.

    2016-05-01

    The complementarity between signaling and randomness in any communicated resource that can simulate singlet statistics is generalized by relaxing the assumption of free will in the choice of measurement settings. We show how to construct an ontological extension for quantum mechanics (QMs) through the oblivious embedding of a sound simulation protocol in a Newtonian spacetime. Minkowski or other intermediate spacetimes are ruled out as the locus of the embedding by virtue of hidden influence inequalities. The complementarity transferred from a simulation to the extension unifies a number of results about quantum non-locality, and implies that special relativity has a different significance for the ontological model and for the operational theory it reproduces. Only the latter, being experimentally accessible, is required to be Lorentz covariant. There may be certain Lorentz non-covariant elements at the ontological level, but they will be inaccessible at the operational level in a valid extension. Certain arguments against the extendability of QM, due to Conway and Kochen (2009) and Colbeck and Renner (2012), are attributed to their assumption that the spacetime at the ontological level has Minkowski causal structure.

  1. Extendable pipe crawler

    DOEpatents

    Hapstack, Mark

    1991-01-01

    A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by "inchworm"-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward.

  2. Extendable pipe crawler

    DOEpatents

    Hapstack, M.

    1991-05-28

    A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

  3. An Extended Duopoly Game.

    ERIC Educational Resources Information Center

    Eckalbar, John C.

    2002-01-01

    Illustrates how principles and intermediate microeconomic students can gain an understanding for strategic price setting by playing a relatively large oligopoly game. Explains that the game extends to a continuous price space and outlines appropriate applications. Offers the Mathematica code to instructors so that the assumptions of the game can…

  4. Towards Extended Vantage Theory

    ERIC Educational Resources Information Center

    Glaz, Adam

    2010-01-01

    The applicability of Vantage Theory (VT), a model of (colour) categorization, to linguistic data largely depends on the modifications and adaptations of the model for the purpose. An attempt to do so proposed here, called Extended Vantage Theory (EVT), slightly reformulates the VT conception of vantage by capitalizing on some of the entailments of…

  5. Modelling extended chromospheres

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.

    1986-01-01

    Attention is given to the concept that the warm, partially ionized plasma (presently called chromosphere) associated with such stars as Alpha Boo and Rho Per extends outwards at least several photospheric radii. Calculations are presented for the Mg II K line in light of two input model atmospheres. Specific predictions are deduced from the results obtained by each of the two models.

  6. Extended artistic appreciation.

    PubMed

    Wilson, Robert A

    2013-04-01

    I propose that in at least some cases, objects of artistic appreciation are best thought of not simply as causes of artistic appreciation, but as parts of the cognitive machinery that drives aesthetic appreciation. In effect, this is to say that aesthetic appreciation operates via extended cognitive systems.

  7. Mapping the Inner Halo of the Galaxy with 2MASS-Selected Horizontal-Branch Candidates

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Beers, Timothy C.; Kurtz, Michael J.; Roll, John B.

    2004-03-01

    We use Two Micron All Sky Survey (2MASS) photometry to select blue horizontal-branch (BHB) candidates covering the sky, |b|>15°. A 12.52MASS catalog. We show that a -0.20<(J-H)0<0.10, -0.10<(H-K)0<0.10 color-selected sample of stars is 65% complete for BHB stars and is composed of 47% BHB stars. We apply this photometric selection to the full 2MASS catalog and see no spatial overdensities of BHB candidates at high Galactic latitude, |b|>50°. We insert simulated star streams into the data and conclude that the high Galactic latitude BHB candidates are consistent with having no ~5° wide star stream with density greater than 0.33 objects deg-2 at the 95% confidence level. The absence of observed structure suggests that there have been no major accretion events in the inner halo in the last few Gyr. However, at low Galactic latitudes a two-point angular correlation analysis reveals structure on angular scales θ<~1°. This structure is apparently associated with stars in the thick disk and has a physical scale of 10-100 pc. Interestingly, such structures are expected by cosmological simulations that predict the majority of the thick disk may arise from accretion and disruption of satellite mergers.

  8. Surveying the Galactic Halo with 2MASS-Selected Horizontal Branch Candidates

    NASA Astrophysics Data System (ADS)

    Brown, W. R.; Geller, M. J.; Kenyon, S. J.; Beers, T. C.; Kurtz, M. J.; Roll, J. B.

    2003-12-01

    We use 2MASS photometry to select blue horizontal branch (BHB) candidates covering the sky |b| > 15o. A 12.5 < J0 < 15.5 sample of BHB stars traces the thick disk and inner halo to d⊙ ≃ 9 kpc, with a density 3-5 times that of M giant stars. We base our sample selection strategy on the Century Survey Galactic Halo Project, a survey that provides a complete, spectroscopically-identified sample of blue stars to a similar depth as the 2MASS catalog. We show that a -0.20 < (J-H)0 < 0.10, -0.10 < (H-K)0 < 0.10 color-selected sample of stars is 65% complete for BHB stars, and is composed of 47% BHB stars. We apply this photometric selection to the full 2MASS catalog, and see no spatial overdensities of BHB candidates at high Galactic latitude |b| > 50o. We insert simulated star streams into the data and conclude that the high Galactic latitude BHB candidates are consistent with having no ˜ 5o wide star stream with density greater than 0.33 objects deg-2 at the 95% confidence level. The absence of structure suggests there have been no major accretion events in the inner halo in the last few Gyr. However, at low Galactic latitudes a two-point angular correlation analysis reveals structure on angular scales θ ≲ 1o. This structure is apparently associated with stars in the thick disk, and has a physical scale of 10-100 pc. One possible explanation for this structure is provided by cosmological simulations that predict the majority of the thick disk may arise from accretion and disruption of satellite mergers.

  9. Propelling Extended Objects

    ERIC Educational Resources Information Center

    Humbert, Richard

    2010-01-01

    A force acting on just part of an extended object (either a solid or a volume of a liquid) can cause all of it to move. That motion is due to the transmission of the force through the object by its material. This paper discusses how the force is distributed to all of the object by a gradient of stress or pressure in it, which creates the local…

  10. Phenomenological Modeling of Newly Discovered Eclipsing Binary 2MASS J18024395 + 4003309 = VSX J180243.9+400331

    NASA Astrophysics Data System (ADS)

    Andronov, Ivan L.; Kim, Yonggi; Kim, Young-Hee; Yoon, Joh-Na; Chinarova, Lidia L.; Tkachenko, Mariia G.

    2015-06-01

    We present a by-product of our long term photometric monitoring of cataclysmic variables. 2MASS J18024395 +4003309 = VSX J180243.9 +400331 was discovered in the field of the intermediate polar V1323 Her observed using the Korean 1-m telescope located at Mt. Lemmon, USA. An analysis of the two-color VR CCD observations of this variable covers all the phase intervals for the first time. The light curves show this object can be classified as an Algol-type variable with tidally distorted components, and an asymmetry of the maxima (the O'Connell effect). The periodogram analysis confirms the cycle numbering of Andronov et al. (2012) and for the initial approximation, the ephemeris is used as follows: Min I. BJD = 2456074.4904+0.3348837E . For phenomenological modeling, we used the trigonometric polynomial approximation of statistically optimal degree, and a recent method "NAV" ("New Algol Variable") using local specific shapes for the eclipse. Methodological aspects and estimates of the physical parameters based on analysis of phenomenological parameters are presented. As results of our phenomenological model, we obtained for the inclination i=90°, M1=0.745M⊙, M2=0.854M⊙, M=M1+M2=1.599M⊙, the orbital separation a=1.65°109m=2.37R⊙ and relative radii r1=R1/a=0.314 and r2=R2/a=0.360. These estimates may be used as preliminary starting values for further modeling using extended physical models based on the Wilson & Devinney (1971) code and it's extensions

  11. ION SOURCE

    DOEpatents

    Martina, E.F.

    1958-04-22

    An improved ion source particularly adapted to provide an intense beam of ions with minimum neutral molecule egress from the source is described. The ion source structure includes means for establishing an oscillating electron discharge, including an apertured cathode at one end of the discharge. The egress of ions from the source is in a pencil like beam. This desirable form of withdrawal of the ions from the plasma created by the discharge is achieved by shaping the field at the aperture of the cathode. A tubular insulator is extended into the plasma from the aperture and in cooperation with the electric fields at the cathode end of the discharge focuses the ions from the source,

  12. 2MASS J17112318-2724315: A DEEPLY EMBEDDED LOW-MASS PROTOSTELLAR SYSTEM IN THE B59 MOLECULAR CLOUD

    SciTech Connect

    Riaz, B.; Martin, E. L.; Bouy, H.; Tata, R.

    2009-08-01

    We present near-infrared observations of the low-mass deeply embedded Class 0/I system 2MASS J17112318-2724315 (2M171123) in the B59 molecular cloud. Bright scattered light nebulosity is observed toward this source in the K{sub s} images, that seems to trace the edges of an outflow cavity. We report the detection of a low-luminosity protostar 2M17112255-27243448 (2M17112255) that lies {approx}8'' ({approx}1000 AU) from 2M171123. This is a Class I system, as indicated by its 2-8 {mu}m slope and Infrared Array Camera colors, with an estimated internal luminosity of {approx}0.3 L{sub sun}. We estimate a mass of {approx}0.12-0.25 M{sub sun} for this source, at an age of 0.1-1 Myr. Also presented is detailed modeling of the 2M171123 system. The best-fit parameters indicate a large envelope density of the order of {approx}10{sup -13} g cm{sup -3}, and an intermediate inclination between 53 deg. and 59 deg. The observed K{sub s} -band variability for this system could be explained by slight variability in the mass infall rate between 2.5E-5 and 1.8E-5 M{sub sun} yr{sup -1}. The protostar 2M171123 exhibits a rarely observed absorption feature near 11.3 {mu}m within its 10 {mu}m silicate band. We find a strong correlation between the strength in this 11.3 {mu}m 'edge' and the H{sub 2}O-ice column density, indicating the origin of this feature in the thickness of the ice mantle over the silicate grains.

  13. Extended Testability Analysis Tool

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin; Maul, William A.; Fulton, Christopher

    2012-01-01

    The Extended Testability Analysis (ETA) Tool is a software application that supports fault management (FM) by performing testability analyses on the fault propagation model of a given system. Fault management includes the prevention of faults through robust design margins and quality assurance methods, or the mitigation of system failures. Fault management requires an understanding of the system design and operation, potential failure mechanisms within the system, and the propagation of those potential failures through the system. The purpose of the ETA Tool software is to process the testability analysis results from a commercial software program called TEAMS Designer in order to provide a detailed set of diagnostic assessment reports. The ETA Tool is a command-line process with several user-selectable report output options. The ETA Tool also extends the COTS testability analysis and enables variation studies with sensor sensitivity impacts on system diagnostics and component isolation using a single testability output. The ETA Tool can also provide extended analyses from a single set of testability output files. The following analysis reports are available to the user: (1) the Detectability Report provides a breakdown of how each tested failure mode was detected, (2) the Test Utilization Report identifies all the failure modes that each test detects, (3) the Failure Mode Isolation Report demonstrates the system s ability to discriminate between failure modes, (4) the Component Isolation Report demonstrates the system s ability to discriminate between failure modes relative to the components containing the failure modes, (5) the Sensor Sensor Sensitivity Analysis Report shows the diagnostic impact due to loss of sensor information, and (6) the Effect Mapping Report identifies failure modes that result in specified system-level effects.

  14. 2MASS photometry and kinematical studies of open cluster NGC 188

    NASA Astrophysics Data System (ADS)

    Elsanhoury, W. H.; Haroon, A. A.; Chupina, N. V.; Vereshchagin, S. V.; Sariya, Devesh P.; Yadav, R. K. S.; Jiang, Ing-Guey

    2016-11-01

    In this paper, we present our results for the photometric and kinematical studies of old open cluster NGC 188. We determined various astrophysical parameters like limited radius, core and tidal radii, distance, luminosity and mass functions, total mass, relaxation time etc. for the cluster using 2MASS catalog. We obtained the cluster's distance from the Sun as 1721 ± 41 pc and log (age)= 9.85 ± 0.05 at Solar metallicity. The relaxation time of the cluster is smaller than the estimated cluster age which suggests that the cluster is dynamically relaxed. Our results agree with the values mentioned in the literature. We also determined the clusters apex coordinates as (281°.88, -44∘ .76) using AD-diagram method. Other kinematical parameters like space velocity components, cluster center and elements of Solar motion etc. have also been computed.

  15. Supervoids in the WISE-2MASS catalogue imprinting cold spots in the cosmic microwave background

    NASA Astrophysics Data System (ADS)

    Finelli, F.; García-Bellido, J.; Kovács, A.; Paci, F.; Szapudi, I.

    2016-01-01

    The Cold Spot (CS) is a clear feature in the cosmic microwave background (CMB); it could be of primordial origin, or caused by a intervening structure along the line of sight. We identified a large projected underdensity in the recently constructed WISE-2MASS all-sky infrared galaxy catalogue aligned with the CS direction at (l, b) ≈ (209°, -57°). It has an angular size of tens of degrees, and shows a ˜20 per cent galaxy underdensity in the centre. Moreover, we find another large underdensity in the projected WISE-2MASS galaxy map at (l, b) ≈ (101°, 46°) (hereafter Draco supervoid), also aligned with a CMB decrement, although less significant than that of the CS direction. Motivated by these findings, we develop spherically symmetric Lemaitre-Tolman-Bondi (LTB) compensated void models to explain the observed CMB decrements with these two underdensities, or `supervoids'. Within our perturbative treatment of the LTB voids, we find that the integrated Sachs-Wolfe and Riess-Sciama effects due to the Draco supervoid can account for the CMB decrement observed in the same direction. On the contrary, the extremely deep CMB decrement in the CS direction is more difficult to explain by the presence of the CS supervoid only. Nevertheless, the probability of a random alignment between the CS and the corresponding supervoid is disfavoured, and thus its contribution as a secondary anisotropy cannot be neglected. We comment on how the approximations used in this paper, in particular the assumption of spherical symmetry, could change quantitatively our conclusions and might provide a better explanation for the CMB CS.

  16. Potential Nearby M Dwarf Stars Selected from the 2MASS Catalogs

    NASA Astrophysics Data System (ADS)

    Robertson, Thomas H.; Thompson, Dayna L.

    2016-01-01

    Potential nearby red dwarf stars have been selected from the 2MASS catalogs using assumptions about apparent magnitudes and colors. Candidate stars in this study are north of the celestial equator and have been restricted to galactic latitudes greater than 20 degrees from the galactic plane to permit subsequent aperture photometry with small telescopes. Stars with close companions have also been eliminated. Most probable M giant stars were eliminated using the (J-H) - (H-K) two-color diagram. Proper motions were obtained from the USNO-B catalog. Additional potential M giant stars were eliminated by removing stars with very low proper motions. Known nearby stars were removed from the list and stars with proper motions greater than 0.175 arcsec yr-1 were also removed, since such stars will likely be studied in other programs devoted to stars of known proper motion. Photometric parallaxes for the candidate stars were computed using 2MASS photometry and stars having average photometric distances of 25 pc or less were retained. A sample of 121 stars was produced. These stars are being observed using Kron-Cousins R, I and CaH photometry. To date about 75% of the program stars have been observed. All are confirmed dwarf stars and about 50% have distances of 25 pc or less based on photometric parallaxes using Kron-Cousins photometry.This publication makes use of data products from the Two Micron All Sky Survey and the U.S. Naval Observatory B1.0 Catalog. Services and products provided by the Strasbourg Astronomical Data Center (CDS) and US Virtual Astronomical Observatory (VAO) were used in processing the data. Observations have been obtained using the telescopes of the Southeastern Association for Research in Astronomy (SARA).

  17. Swift/XRT follow-up observations of unidentified INTEGRAL sources

    NASA Astrophysics Data System (ADS)

    Maiorano, E.; Landi, R.; Parisi, P.; Masetti, N.; Bassani, L.; Malizia, A.; Bazzano, A.; Ubertini, P.; Bird, A. J.; Jimenez-Bailon, E.; Chavushyan, V.; Galaz, G.; Minniti, D.; Morelli, L.

    2010-10-01

    We report on X-ray follow-up observations performed with Swift/XRT of 3 unidentified INTEGRAL sources listed in the fourth IBIS Survey Catalogue (Bird et al. 2010, ApJS, 186, 1). IGR J08190-3835 Within the IBIS uncertainty XRT detects one source with a statistical significance of 5.8 sigma in the energy range 0.3-10 keV and 5.6 sigma above 3 keV. This object, located at RA(J2000) = 08h 19m 11.3s and Dec(J2000) = -38d 33m 09s (5 arcsec uncertainty), is associated with a 2MASS extended object (2MASX J08191136-3833104) classified as a galaxy in the NED archive and is positionally coincident with radio source NVSS J081910-383307.

  18. NEUTRON SOURCE

    DOEpatents

    Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

    1959-01-13

    A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

  19. Reduced Extended MHD

    NASA Astrophysics Data System (ADS)

    Morrison, P. J.; Abdelhamid, H. M.; Grasso, D.; Hazeltine, R. D.; Lingam, M.; Tassi, E.

    2015-11-01

    Over the years various reduced fluid models have been obtained for modeling plasmas, with the goal of capturing important physics while maintaining computability. Such models have included the physics contained in various generalizations of Ohm's law, including Hall drift and electron inertia. In a recent publication it was shown that full 3D extended MHD is a Hamiltonian system by finding its noncanonical Poisson bracket. Subsequently, this bracket was shown to be derivable from that for Hall MHD by a series of remarkable transformations, which greatly simplifies the proof of the Jacobi identity and allows one to immediately obtain generalizations of the helicity and cross helicity. In this poster we use this structure to obtain exact reduced fluid models with the effects of full two-fluid theory. Results of numerical computations of collisionless reconnection using an exact reduced 4-field model will be presented and analytical comparisons of mode structure of previous reduced models will be made.

  20. Extended Ewald summation technique

    NASA Astrophysics Data System (ADS)

    Kylänpää, Ilkka; Räsänen, Esa

    2016-09-01

    We present a technique to improve the accuracy and to reduce the computational labor in the calculation of long-range interactions in systems with periodic boundary conditions. We extend the well-known Ewald method by using a linear combination of screening Gaussian charge distributions instead of only one. This enables us to find faster converging real-space and reciprocal space summations. The combined simplicity and efficiency of our method is demonstrated, and the scheme is readily applicable to large-scale periodic simulations, classical as well as quantum. Moreover, apart from the required a priori optimization the method is straightforward to include in most routines based on the Ewald method within, e.g., density-functional, molecular dynamics, and quantum Monte Carlo calculations.

  1. Conbined noble gas and stable isotope constraints on nitrogen gas sources within sedimentary basins. Final report for period 15 March 1996 - 14 March 1999 extended to 14 March 2000

    SciTech Connect

    Ballentine, C.J.; Halliday, Alexander N.; Lollar, B. Sherwood

    2001-05-01

    Nitrogen is one of the major non-hydrocarbon gases found in natural gas reservoirs. The objective of this work was to combine the information available from both noble gas and stable isotope systematics to understand the origin of nitrogen and related gas sources, transport behavior, and mass balance within natural gas reservoirs and sedimentary basin systems. The goals achieved are summarized under the following headings: Noble gas and stable isotopes in nitrogen-rich natural gases; Noble gases in groundwater; and Characterization of magmatic and crustal noble gas input into basin systems. Lists of publications and presentations are included.

  2. THE EXTENDED VIRGO CLUSTER CATALOG

    SciTech Connect

    Kim, Suk; Rey, Soo-Chang; Lee, Youngdae; Chung, Jiwon; Pak, Mina; Yi, Wonhyeong; Lee, Woong; Jerjen, Helmut; Lisker, Thorsten; Sung, Eon-Chang

    2015-01-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg{sup 2} or 60.1 Mpc{sup 2}. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s{sup –1}. In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

  3. Extending the ICRF to Higher Radio Frequencies

    NASA Technical Reports Server (NTRS)

    Jacobs, C. S.; Jones, D. L.; Lanyi, G. E.; Lowe, S. T.; Naudet, C. J.; Resch, G. M.; Steppe, J. A.; Zhang, L. D.; Ulvestad, J. S.; Taylor, G. B.

    2002-01-01

    The ICRF forms the basis for all astrometry including use as the inertial coordinate system for navigating deep space missions. This frame was defined using S/X-band observations over the past 20+ years. In January 2002, the VLBA approved our proposal for observing time to extend the ICRF to K-band (24 GHz) and Q-band (43 GHz). The first step will be observations at K- and Q-bands on a subset of ICRF sources. Eventually, K- and Q-band multi-epoch observations will be used to estimate positions, flux density and source structure for a large fraction of the current S/X-band ICRF source list. This work will benefit the radio astronomy community by extending the VLBA calibrator list at these bands. In the longer term, we would also like to extend the ICRF to Ka-band (32 GHz). A celestial reference frame will be needed at this frequency to support deep space navigation. A navigation demonstration is being considered for NASA's Mars 2005 mission. The initial K- and Q-band work will serve to identify candidate sources at Ka-band for use with that mission.

  4. Discovery of a Very Young Field L Dwarf, 2MASS J01415823-4633574

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, J. Davy; Barman, Travis S.; Burgasser, Adam J.; McGovern, Mark R.; McLean, Ian S.; Tinney, Christopher G.; Lowrance, Patrick J.

    2006-03-01

    While following up L dwarf candidates selected photometrically from the Two Micron All Sky Survey, we uncovered an unusual object designated 2MASS J01415823-4633574. Its optical spectrum exhibits very strong bands of vanadium oxide but abnormally weak absorptions by titanium oxide, potassium, and sodium. Morphologically, such spectroscopic characteristics fall intermediate between old field early-L dwarfs [log(g)~5] and very late M giants [log(g)~0], leading us to favor low gravity as the explanation for the unique spectral signatures of this L dwarf. Such a low gravity can be explained only if this L dwarf is much lower in mass than a typical old field L dwarf of similar temperature and is still contracting to its final radius. These conditions imply a very young age. Further evidence of youth is found in the near-infrared spectrum, including a triangular-shaped H-band continuum, reminiscent of young brown dwarf candidates discovered in the Orion Nebula Cluster. Using the above information along with comparisons to brown dwarf atmospheric and interior models, our current best estimate is that this L dwarf has an age of 1-50 Myr and a mass of 6-25MJ. Although the lack of a lithium detection (pseudo-equivalent width <1 Å) might appear to contradict other evidence of youth, we suggest that lithium becomes weaker at lower gravity like all other alkali lines and thus needs to be carefully considered before being used as a diagnostic of age or mass for objects in this regime. The location of 2MASS 0141-4633 on the sky coupled with a distance estimate of ~35 pc and the above age estimate suggests that this object may be a brown dwarf member of either the 30 Myr old Tucana/Horologium association or the ~12 Myr old β Pic moving group. Distance as determined through trigonometric parallax (underway) and a measure of the total space motion are needed to test this hypothesis. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as

  5. CIRCUMSTELLAR ENVIRONMENT AND EFFECTIVE TEMPERATURE OF THE YOUNG SUBSTELLAR ECLIPSING BINARY 2MASS J05352184-0546085

    SciTech Connect

    Mohanty, Subhanjoy; Stassun, Keivan G.; Mathieu, Robert D.

    2009-05-20

    We present new Spitzer IRAC/PU/MIPS photometry from 3.6 to 24 {mu}m, and new Gemini GMOS photometry at 0.48 {mu}m, of the young brown dwarf eclipsing binary 2MASS J05352184-0546085, located in the Orion Nebula Cluster. No excess disk emission is detected. The measured fluxes at {lambda} {<=} 8 {mu}m are within 1{sigma} ({approx}<0.1 mJy) of a bare photosphere, and the 3{sigma} upper limit at 16 {mu}m is a mere 0.04 mJy above the bare photospheric level. Together with the known properties of the system, this implies the absence of optically thick disks around the individual components. It also implies that if any circumbinary disk is present, it must either be optically thin and extremely tenuous (10{sup -10} M {sub sun}) if it extends in to within {approx}0.1 AU of the binary (the approximate tidal truncation radius), or it must be optically thick with a large inner hole, >0.6-10 AU in radius depending on degree of flaring. The consequence in all cases is that disk accretion is likely to be negligible or absent. This supports the recent proposal that the strong H{alpha} emission in the primary (more massive) brown dwarf results from chromospheric activity, and thereby bolsters the hypothesis that the surprising T {sub eff} inversion observed between the components is due to strong magnetic fields on the primary. Our data also set constraints on the T {sub eff} of the components independent of spectral type, and thereby on models of the aforementioned magnetic field effects. We discuss the consequences for the derived fundamental properties of young brown dwarfs and very low mass stars in general. Specifically, if very active isolated young brown dwarfs and very low mass stars suffer the same activity/field related effects as the 2M0535-05 primary, the low-mass stellar/substellar initial mass function currently derived from standard evolutionary tracks may be substantially in error.

  6. Extended chameleon models

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Tamanini, Nicola

    2016-05-01

    We extend the chameleon models by considering scalar-fluid theories where the coupling between matter and the scalar field can be represented by a quadratic effective potential with density-dependent minimum and mass. In this context, we study the effects of the scalar field on Solar System tests of gravity and show that models passing these stringent constraints can still induce large modifications of Newton's law on galactic scales. On these scales we analyze models which could lead to a percent deviation of Newton's law outside the virial radius. We then model the dark matter halo as a Navarro-Frenk-White profile and explicitly find that the fifth force can give large contributions around the galactic core in a particular model where the scalar field mass is constant and the minimum of its potential varies linearly with the matter density. At cosmological distances, we find that this model does not alter the growth of large scale structures and therefore would be best tested on galactic scales, where interesting signatures might arise in the galaxy rotation curves.

  7. Giotto Extended Mission (GEM)

    NASA Technical Reports Server (NTRS)

    Wilkins, D. E. B.; Grensemann, M.

    1991-01-01

    The primary objectives of the Giotto Extended Mission (GEM), are to determine the composition and physical state of the Grigg Skjellerup Comet's nucleus; to determine the processes that govern the composition and distribution of neutral and ionized species in the cometary atmosphere. Giotto consists of a single European Space Agency (ESA) spacecraft that was launched in 1985 from Center Spatial Guyanis in French Guiana on an Ariane launch vehicle. After a successful launch into geostationary orbit and a heliocentric transfer trajectory, the spacecraft successfully encountered Halley's Comet in 1986. One month after encountering Halley's Comet, Mar. 1986, the spacecraft was placed in hibernation in a heliocentric orbit slightly less than 1 AU. Between Feb. and Jul. 1990 the spacecraft was successfully reactivated, checked out, and placed on a trajectory course to intercept comet Grigg Skjellerup. The spacecraft has been in hibernation since Jul. 1990. Information is presented in tabular form in the following areas: coverage goals, Deep Space Network Support, frequency assignments, telemetry, command, and tracking support responsibility.

  8. An Extended Lagrangian Method

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing

    1995-01-01

    A unique formulation of describing fluid motion is presented. The method, referred to as 'extended Lagrangian method,' is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. The present method and the Arbitrary Lagrangian-Eulerian (ALE) method have a similarity in spirit-eliminating the cross-streamline numerical diffusion. For this purpose, we suggest a simple grid constraint condition and utilize an accurate discretization procedure. This grid constraint is only applied to the transverse cell face parallel to the local stream velocity, and hence our method for the steady state problems naturally reduces to the streamline-curvature method, without explicitly solving the steady stream-coordinate equations formulated a priori. Unlike the Lagrangian method proposed by Loh and Hui which is valid only for steady supersonic flows, the present method is general and capable of treating subsonic flows and supersonic flows as well as unsteady flows, simply by invoking in the same code an appropriate grid constraint suggested in this paper. The approach is found to be robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multi-dimensional discontinuities with a high level of accuracy, similar to that found in one-dimensional problems.

  9. Development of a high-resolution soft x-ray (30--1500 eV) beamline at the Advanced Light Source and its use for the study of angle-resolved photoemission extended fine structure

    SciTech Connect

    Huff, W R.A.

    1996-02-01

    ALS Bending magnet beamline 9.3.2 is for high resolution spectroscopy, with circularly polarized light. Fixed included-angle SGM uses three gratings for 30--1500 eV photons; circular polarization is produced by an aperture for selecting the beam above or below the horizontal plane. Photocurrent from upper and lower jaws of entrance slit sets a piezoelectric drive feedback loop on the vertically deflecting mirror for stable beam. End station has a movable platform. With photomeission data from Stanford, structure of c(2{times}2)P/Fe(100) was determined using angle-resolved photoemission extended fine structure (ARPEFS). Multiple-scattering spherical-wave (MSSW) calculations indicate that P atoms adsorb in fourfold hollow sites 1.02A above the first Fe layer. Self-consistent-field X{alpha} scattered wave calculation confirm that the Fe{sub 1}-Fe{sub 2} space is contracted for S/Fe but not for P/Fe; comparison is made to atomic N and O on Fe(100). Final-state effects on ARPEFS curves used literature data from the S 1s and 2p core levels of c(2{times}2)S/Ni(001); a generalized Ramsauer-Townsend splitting is present in the 1s but not 2p data. An approximate method for analyzing ARPEFS data from a non-s initial state using only the higher-{ell} partial wave was tested successfully. ARPEFS data from clean surfaces were collected normal to Ni(111) (3p core levels) and 5{degree} off-normal from Cu(111)(3s, 3p). Fourier transforms (FT) resemble adsorbate systems, showing backscattering signals from atoms up to 4 layers below emitters. 3p FTs show scattering from 6 nearest neighbors in the same crystal layer as the emitters. MSSW calulation indicate that Cu 3p photoemission is mostly d-wave. FTs also indicate double-scattering and single-scattering from laterally distant atoms; calculations indicate that the signal is dominated by photoemission from the first 2 crystal layers.

  10. Motion Verified Red Stars (MoVeRS): A Catalog of Proper Motion Selected Low-mass Stars from WISE, SDSS, and 2MASS

    NASA Astrophysics Data System (ADS)

    Theissen, Christopher A.; West, Andrew A.; Dhital, Saurav

    2016-02-01

    We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS Data Release 10 (DR10), Two Micron All-Sky Survey (2MASS) point-source catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r - i, i - z, r - z, z - J, and z - W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2σ uncertainty were included. Our Motion Verified Red Stars catalog is available through SDSS CasJobs and VizieR.

  11. Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. III. The "Wide" L3.5/L4 Dwarf Binary 2Mass J15500845+1455180AB

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Dhital, Saurav; West, Andrew A.

    2009-12-01

    We report the identification of 2MASS J15500845+1455180 as a 0farcs9 L dwarf visual binary. This source is resolved in Sloan Digital Sky Survey (SDSS) images and in near-infrared imaging with the Infrared Telescope Facility SpeX imager/spectrometer. The two components, oriented along a north-south axis, have similar brightnesses in the near-infrared (ΔK ≈ 0.2 mag), although the fainter northern component is redder in J-K color. Resolved near-infrared spectroscopy indicates spectral types of L3.5 and L4, consistent with its L3 combined-light optical classification based on the SDSS data. Physical association is confirmed through common proper motion, common spectrophotometric distances and low probability of chance alignment. The projected physical separation of 2MASS J1550+1455AB, 30 ± 3 AU at an estimated distance of 33 ± 3 pc, makes it the widest L dwarf-L dwarf pair identified to date, although such a separation is not unusual among very low mass field binaries. The angular separation and spectral composition of this system makes it an excellent target for obtaining a precise lithium depletion age and a potential age standard for low-temperature atmosphere studies.

  12. Extragalactic Radio Sources

    ERIC Educational Resources Information Center

    Kellerman, Kenneth I.

    1973-01-01

    Discusses new problems arising from the growing observational data through radio telescope arrays, involving the origin of radio sources, apparent superluminal velocities, conversion of radio sources to relativistic particles, and the nature of compact opaque and extended transparent sources. New physics may be needed to answer these cosmological…

  13. Intravenous glucose preparation as the source of an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae infections in the neonatal unit of a regional hospital in KwaZulu-Natal.

    PubMed

    Moodley, Prashini; Coovadia, Yacoob M; Sturm, A Willem

    2005-11-01

    In the last week of May 2005, staff at Mahatma Gandhi Memorial Hospital in KwaZulu-Natal realised that many babies in the high-care nursery ward had bloodstream infections involving Klebsiella pneumoniae bacteria. Attempts to identify a common source of infection failed. The ward was therefore closed and new babies needing high care were admitted to another empty ward. Despite this, babies still became infected. This resulted in a request for assistance from the Department of Medical Microbiology of the Nelson R Mandela School of Medicine. A search for common factors through case history studies of the 26 infected babies showed that blood cultures of the babies remained positive despite the administration of appropriate antibiotics. Different options that could explain this were investigated. The organism was found in intravenous glucose preparations used for multiple dosing. Unopened vials of the same medication were sterile. The nursery was found to lack proper hand-wash facilities and to be overcrowded and understaffed. Reinforcement of hand hygiene and a ban on the multiple dosing of medicines stopped the outbreak. In conclusion, this outbreak resulted from a combination of factors among which lack of hand hygiene and multiple dosing of an intravenous glucose preparation were most significant.

  14. The extended Touschek lifetime

    SciTech Connect

    Bizek, H.M.

    1996-02-01

    With the advent of synchrotron radiation sources, the issue of beam lifetime becomes increasingly important. Users of these machines need to perform experiments which seldom last 15 minutes, but require hours for their completion. Therefore, the beam should circulate stably for hours. The beam of the Advanced Photon Source (APS) storage ring at Argonne National Laboratory is assumed to circulate stably for a minimum of 10 hours. The main contributions to the total beam lifetime (which is the inverse of the loss rate) come from residual gas scattering and Touschek scattering. The residual gas scattering is comprised of single Coulomb scattering and bremsstrahlung. The single-Coulomb scattering involves elastic collisions, while bremsstrahlung involves inelastic collisions, between the bunch and the surrounding residual gas. In the calculation the authors take the gas to be nitrogen at a pressure of 1 nTorr. Touschek scattering involves scattering of particles within the bunch, transferring energy among themselves. Such an energy transfer, if large enough, may eject the particle out of the bunch, thus causing it to be lost. Let us not forget the residual-gas lifetime. As pointed out, the calculation of this lifetime is done for the very low pressure of 1 nTorr. If the pressure is higher, the residual-gas lifetime will be smaller. This will further reduce the total beam lifetime, causing it to slip deeper below the minimum lifetime for stable storage ring operation. They begin this article by reviewing the Touschek integral and the associated limits of integration. The program ZAP has been altered to take into account the possible loss due to induced betatron oscillations. At each lattice position the energy loss required to produce, by coupling, a vertical oscillation that exceeds the vertical aperture is calculated. When this energy loss is less than the rf bucket half-height, it replaces the rf bucket half-height in the Touschek integral.

  15. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  16. Relic gravitational waves and extended inflation

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.; Wilczek, Frank

    1990-01-01

    In extended inflation, a new version of inflation where the transition from an inflationary to a radiation-dominated universe is accomplished by bubble nucleation, bubble collisions supply a potent - and potentially detectable - source of gravitational waves. The energy density in relic gravitons from bubble collisions is expected to be about 0.00005 of closure density. Their characteristic wavelength depends on the reheating temperature. If black holes are produced by bubble collisions, they will evaporate, producing shorter-wavelength gravitons.

  17. New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence

    NASA Astrophysics Data System (ADS)

    Gizis, John E.; Monet, David G.; Reid, I. Neill; Kirkpatrick, J. Davy; Liebert, James; Williams, Rik J.

    2000-08-01

    We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with Ks<12. Spectroscopic follow-up observations identify 53 M7-M9.5 dwarfs and seven L dwarfs. The observed space density is 0.0045+/-0.0008 M8-M9.5 dwarfs per cubic parsec, without accounting for biases, consistent with a mass function that is smooth across the stellar/substellar limit. We show the observed frequency of Hα emission peaks at ~100% for M7 dwarfs and then decreases for cooler dwarfs. In absolute terms, however, as measured by the ratio of Hα to bolometric luminosity, none of the ultracool M dwarfs can be considered very active compared to earlier M dwarfs, and we show that the decrease that begins at spectral type M6 continues to the latest L dwarfs. We find that flaring is common among the coolest M dwarfs and estimate the frequency of flares at 7% or higher. We show that the kinematics of relatively active (EW>6 Å) ultracool M dwarfs are consistent with an ordinary old disk stellar population, while the kinematics of inactive ultracool M dwarfs are more typical of a 0.5 Gyr old population. The early L dwarfs in the sample have kinematics consistent with old ages, suggesting that the hydrogen-burning limit is near spectral types L2-L4. We use the available data on M and L dwarfs to show that chromospheric activity drops with decreasing mass and temperature and that at a given (M8 or later) spectral type, the younger field (brown) dwarfs are less active than many of the older, more massive field stellar dwarfs. Thus, contrary to the well-known stellar age-activity relationship, low activity in field ultracool dwarfs can be an indication of comparative youth and substellar mass.

  18. Variable stars in the VVV globular clusters. I. 2MASS-GC 02 and Terzan 10

    SciTech Connect

    Alonso-García, Javier; Dékány, István; Catelan, Márcio; Ramos, Rodrigo Contreras; Gran, Felipe; Leyton, Paul; Minniti, Dante; Amigo, Pía E-mail: idekany@astro.puc.cl E-mail: rcontrer@astro.puc.cl E-mail: pia.amigo@uv.cl E-mail: dante@astrofisica.cl

    2015-03-01

    The VISTA Variables in the Vía Láctea (VVV) ESO Public Survey is opening a new window to study inner Galactic globular clusters (GCs) using their variable stars. These GCs have been neglected in the past due to the difficulties caused by the presence of elevated extinction and high field stellar densities in their lines of sight. However, the discovery and study of any present variables in these clusters, especially RR Lyrae stars, can help to greatly improve the accuracy of their physical parameters. It can also help to shed some light on the questions raised by the intriguing Oosterhoff dichotomy in the Galactic GC system. In a series of papers we plan to explore variable stars in the GCs falling inside the field of the VVV survey. In this first paper, we search for and study the variables present in two highly reddened, moderately metal-poor, faint, inner Galactic GCs: 2MASS-GC 02 and Terzan 10. We report the discovery of sizable populations of RR Lyrae stars in both GCs. We use near-infrared period–luminosity relations to determine the color excess of each RR Lyrae star, from which we obtain both accurate distances to the GCs and the ratios of the selective-to-total extinction in their directions. We find the extinction toward both clusters to be elevated, non-standard, and highly differential. We also find both clusters to be closer to the Galactic center than previously thought, with Terzan 10 being on the far side of the Galactic bulge. Finally, we discuss their Oosterhoff properties, and conclude that both clusters stand out from the dichotomy followed by most Galactic GCs.

  19. Association of Lp-PLA2 Mass and Aysmptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients

    PubMed Central

    Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Gao, Pingjin; Zhu, Dingliang

    2015-01-01

    Background and Purpose Intracranial arterial stenosis (ICAS) is a common cause of ischemic stroke in Asians, whereas whites tend to have more extracranial lesions. Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been associated with ischemic stroke by a large amount of work. However, there are few studies focusing on the relationship of Lp-PLA2 and asymptomatic ICAS or extracranial arterial stenosis (ECAS). Wehereby sought to explore the relationship of Lp-PLA2 and ICAS, ECAS and concurrent stenosis in stroke-free hypertensive patients in Chinese population. Methods All the subjects were evaluated for the presence and severity of ICAS and ECAS through computerized tomographic angiography (CTA) covered the whole brain down to the level of aortic arch. Lp-PLA2 mass was measured by enzyme linked immunoassay. The association of Lp-PLA2 and vascular stenosis was analyzed through multivariate logistic regression. Results Among 414 participants, 163 (39.4%) had no ICAS or ECAS, 63 (15.2%) had ECAS only, 111 (26.8%) had ICAS only and 77 (18.6%) had concurrent extraintracranial stenosis. Lp-PLA2 mass was significantly associated with isolated ICAS (OR: 2.3; 95% CI: 1.14-4.64), and concurrent stenosis (OR: 3.93; 95% CI: 1.62-9.51), but was not related to isolated ECAS (OR: 1.54; 95% CI: 0.68-3.48). Lp-PLA2 mass was also associated with moderate to severe ICAS no matter how was the ECAS. Moreover, patients with higher Lp-PLA2 mass showed more sever ICAS and had more intracranial arterial lesions. Conclusion This study revealed the association of Lp-PLA2 mass with ICAS in stroke-free hypertensive patients in Chinese population. The further long-term cohort study was warranted to elucidate the concrete effect of Lp-PLA2 on the asymptomatic ICAS. PMID:26098634

  20. Extended Active Disturbance Rejection Controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2014-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  1. Extended Active Disturbance Rejection Controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2016-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  2. Extended active disturbance rejection controller

    NASA Technical Reports Server (NTRS)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2012-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  3. Database Cross-Correlation at Scale: A Complete Census of Cool and Peculiar Brown Dwarfs in the 2MASS/SDSS Overlap

    NASA Astrophysics Data System (ADS)

    Metchev, Stanimir

    Cross-correlation of surveys at different wavelengths is an effective way to leverage existing data for the generation of new science. We propose to perform a cross-match of the complete 2MASS and SDSS surveys as a demonstration of database cross-correlation at scale. The specific science case focuses on identifying cool brown dwarfs. Hundreds of L and T dwarfs have been discovered in the solar neighborhood, ~90% of which from 2MASS or SDSS. These have offered an unprecedented empirical context for the creation of sophisticated substellar phenomenology. A few dozen peculiar L and T dwarfs have also emerged from the larger sample. Their unusual spectral energy distributions have been particularly informative about the ranges of temperature, surface gravity, and dust content in ultra-cool atmospheres. Nevertheless, fundamental aspects of our knowledge of substellar astrophysics remain fragmented. The local space density of T dwarfs is hardly known to better than a factor of several. In fact, some of the nearest cool brown dwarfs may have escaped detection. Dust and cloud dynamics in ultra-cool atmospheres, and their dependence on temperature, gravity, and metallicity remain poorly understood. And in all likelihood, the few known examples of peculiar L and T dwarfs represent merely the extremes of a broad range of existing atmospheric conditions that have yet to be revealed. A combined search on 2MASS and SDSS is an effective way to generate a large, complete sample of L and T dwarfs to address these shortcomings. Cross-correlation of the two surveys can probe deeper, to cooler effective temperatures, and to a higher completeness level than searches on either survey alone. We validated this approach through a test cross-match of the 2099 sq.deg overlap area between 2MASS and SDSS Data Release 1. The demonstration project resulted not only in the first unbiased estimate of the space density and luminosity function of T0-T8 dwarfs, but also in doubling of the then known

  4. Einstein observations of extended galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Seward, F. D.

    1979-01-01

    Features of the X-ray pictures taken aboard the space observatory are presented. Imaging proportional counter pictures in three broad X-ray energy ranges were obtained. The X-ray spectrum of supernova remnants is described.

  5. Detecting an Extended Light Source through a Lens

    ERIC Educational Resources Information Center

    Litaker, E. T.; Machacek, J. R.; Gay, T. J.

    2011-01-01

    We present a Monte Carlo simulation of a cylindrical luminescent volume and a typical lens-detector system. The results of this simulation yield a graphically simple picture of the regions within the cylindrical volume from which this system detects light. Because the cylindrical volume permits large angles of incidence, we use a modification of…

  6. Searching for heavily obscured post-AGB stars and planetary nebulae. II. Near-IR observations of IRAS sources

    NASA Astrophysics Data System (ADS)

    Ramos-Larios, G.; Guerrero, M. A.; Suárez, O.; Miranda, L. F.; Gómez, J. F.

    2012-09-01

    The most massive AGB stars are expected to result in heavily obscured post-AGB stars, proto-PNe and PNe with highly axisymmetric morphologies. To investigate this evolutionary connection, we have selected a sample of 165 presumably obscured IRAS post-AGB star and PN candidates and obtained near-IR JHK images for 164 of them. These images, in conjunction with DSS, 2MASS, Spitzer GLIMPSE, MSX, AKARI, and IRAS archival data, have allowed us to identify the near-IR counterparts of 154 of these sources, providing reliable finding charts and coordinates. Near-IR narrow-band Brγ, H2, and K continuum images were acquired for 6 of these sources that were found to be resolved in near-IR JHK images. Among the extended post-AGB source and PN candidates, three are round and seven have bipolar morphologies. Five of the extended sources are ionized and may have thus entered the PN stage. We note that all extended sources with water maser emission have bipolar morphology. We have investigated the Galactic distribution of sources with the largest flux drop from the 9 μm AKARI band to the near-IR J band and found that the width of the distribution in Galactic latitude is consistent with those of bipolar PNe and DUPLEX (DUst-Prominent Longitudinally EXtended) sources. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (081.D-0812), observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, and on observations with AKARI, a JAXA project with the participation of ESA.

  7. Migration and natural fate of a coal tar creosote plume. 2. Mass balance and biodegradation indicators

    NASA Astrophysics Data System (ADS)

    King, Mark W. G.; Barker, James F.; Devlin, John F.; Butler, Barbara J.

    1999-10-01

    A source of coal tar creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. A mass balance indicated that ongoing transformation occurred for seven study compounds. Phenol migrated as a discrete slug plume and almost completely disappeared after 2 years, after being completely leached from the source early in the study. The m-xylene plume migrated outward to a maximum distance at approximately 2 years, and then receded back towards the source as the rate of mass flux out of the source decreased to below the overall rate of plume transformation. Carbazole showed similar behaviour, although the reversal in plume development occurred more slowly. The dibenzofuran plume remained relatively constant in extent and mass over the last 2 years of monitoring, despite constant source input over this period, providing evidence that the dibenzofuran plume was at steady state. Meanwhile, the naphthalene and 1-methylnaphthalene plumes continued to advance and increase in mass over the observation period, although at a decreasing rate. The phenanthrene plume was also subject to transformation, although measurement of the rate was less conclusive due to the higher proportion of sorbed mass for this compound. Three lines of evidence are presented to evaluate whether the observed plume mass loss was due to microbial biodegradation. Measurement of redox-sensitive parameters in the vicinity of the plume showed the types of changes that would be expected to occur due to plume biodegradation: dissolved oxygen and SO 42- decreased in groundwater within the plume while significant increases were noted for Fe 2+, Mn 2+ and methane. Further evidence that plume mass loss was microbially-mediated was provided by the accumulation of aromatic acids within the plume. Measurements of phospholipid fatty acids (PLFA) in aquifer material indicated that microbial biomass and turnover rate were greater within the plume

  8. LISA source confusion

    SciTech Connect

    Crowder, Jeff; Cornish, Neil J.

    2004-10-15

    The Laser Interferometer Space Antenna will detect thousands of gravitational wave sources. Many of these sources will be overlapping in the sense that their signals will have a nonzero cross correlation. Such overlaps lead to source confusion, which adversely affects how well we can extract information about the individual sources. Here we study how source confusion impacts parameter estimation for galactic compact binaries, with emphasis on the effects of the number of overlaping sources, the time of observation, the gravitational wave frequencies of the sources, and the degree of the signal correlations. Our main findings are that the parameter resolution decays exponentially with the number of overlapping sources and superexponentially with the degree of cross correlation. We also find that an extended mission lifetime is key to disentangling the source confusion as the parameter resolution for overlapping sources improves much faster than the usual square root of the observation time.

  9. Open Source Molecular Modeling

    PubMed Central

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-01-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. PMID:27631126

  10. DETECTION OF A NEARBY HALO DEBRIS STREAM IN THE WISE AND 2MASS SURVEYS

    SciTech Connect

    Grillmair, Carl J.; Cutri, Roc; Masci, Frank J.; Conrow, Tim; Sesar, Branimir; Eisenhardt, Peter R. M.; Wright, Edward L. E-mail: roc@ipac.caltech.edu E-mail: tim@ipac.caltech.edu E-mail: peter.r.eisenhardt@jpl.nasa.gov

    2013-06-01

    Combining the Wide-Field Infrared Survey Explorer All-Sky Release with the Two Micron All Sky Survey Point Source Catalog, we detect a nearby, moderately metal-poor stellar debris stream spanning 24° across the southern sky. The stream, which we designate Alpheus, is at an estimated distance of ∼1.9 kpc. Its position, orientation, width, estimated metallicity, and, to some extent, its distance, are in approximate agreement with what one might expect of the leading tidal tail of the southern globular cluster NGC 288.

  11. FIRST-2MASS RED QUASARS: TRANSITIONAL OBJECTS EMERGING FROM THE DUST

    SciTech Connect

    Glikman, Eilat; Urrutia, Tanya; Lacy, Mark; Djorgovski, S. George; Mahabal, Ashish; Myers, Adam D.; Ross, Nicholas P.; Petitjean, Patrick; Ge, Jian; Schneider, Donald P.; York, Donald G.

    2012-09-20

    We present a sample of 120 dust-reddened quasars identified by matching radio sources detected at 1.4 GHz in the Faint Images of the Radio Sky at Twenty Centimeters survey with the near-infrared Two Micron All Sky Survey catalog and color-selecting red sources. Optical and/or near-infrared spectroscopy provide broad wavelength sampling of their spectral energy distributions that we use to determine their reddening, characterized by E(B - V). We demonstrate that the reddening in these quasars is best described by Small-Magellanic-Cloud-like dust. This sample spans a wide range in redshift and reddening (0.1 {approx}< z {approx}< 3, 0.1 {approx}< E(B - V) {approx}< 1.5), which we use to investigate the possible correlation of luminosity with reddening. At every redshift, dust-reddened quasars are intrinsically the most luminous quasars. We interpret this result in the context of merger-driven quasar/galaxy co-evolution where these reddened quasars are revealing an emergent phase during which the heavily obscured quasar is shedding its cocoon of dust prior to becoming a 'normal' blue quasar. When correcting for extinction, we find that, depending on how the parent population is defined, these red quasars make up {approx}< 15%-20% of the luminous quasar population. We estimate, based on the fraction of objects in this phase, that its duration is 15%-20% as long as the unobscured, blue quasar phase.

  12. Cognitive Transformations and Extended Expertise

    ERIC Educational Resources Information Center

    Menary, Richard; Kirchhoff, Michael

    2014-01-01

    Expertise is extended by becoming immersed in cultural practices. We look at an example of mathematical expertise in which immersion in cognitive practices results in the transformation of expert performance.

  13. Simulating futures in extended common LISP

    NASA Technical Reports Server (NTRS)

    Nachtsheim, Philip R.

    1988-01-01

    Stack-groups comprise the mechanism underlying implementation of multiprocessing in Extended Common LISP, i.e., running multiple quasi-simultaneous processes within a single LISP address space. On the other hand, the future construct of MULTILISP, an extension of the LISP dialect scheme, deals with parallel execution. The source of concurrency that future exploits is the overlap between computation of a value and use of the value. Described is a simulation of the future construct by an interpreter utilizing stack-group extensions to common LISP.

  14. Topological defects in extended inflation

    NASA Technical Reports Server (NTRS)

    Copeland, Edmund J.; Kolb, Edward W.; Liddle, Andrew R.

    1990-01-01

    The production of topological defects, especially cosmic strings, in extended inflation models was considered. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of bubbles when they collide. This mechanism allows a natural combination of inflation and large scale structure via cosmic strings.

  15. Slow-roll extended quintessence

    SciTech Connect

    Chiba, Takeshi; Siino, Masaru; Yamaguchi, Masahide

    2010-04-15

    We derive the slow-roll conditions for a nonminimally coupled scalar field (extended quintessence) during the radiation/matter dominated era extending our previous results for thawing quintessence. We find that the ratio {phi}e/3H{phi} becomes constant but negative, in sharp contrast to the ratio for the minimally coupled scalar field. We also find that the functional form of the equation of state of the scalar field asymptotically approaches that of the minimally coupled thawing quintessence.

  16. Extender for securing a closure

    SciTech Connect

    Thomas, II, Patrick A.

    2012-10-02

    An apparatus for securing a closure such as door or a window that opens and closes by movement relative to a fixed structure such as a wall or a floor. Many embodiments provide a device for relocating a padlock from its normal location where it secures a fastener (such as a hasp) to a location for the padlock that is more accessible for locking and unlocking the padlock. Typically an extender is provided, where the extender has a hook at a first end that is disposed through the eye of the staple of the hasp, and at an opposing second end the extender has an annulus, such as a hole in the extender or a loop or ring affixed to the extender. The shackle of the padlock may be disposed through the annulus and may be disposed through the eye of a second staple to secure the door or window in a closed or open position. Some embodiments employ a rigid sheath to enclose at least a portion of the extender. Typically the rigid sheath has an open state where the hook is exposed outside the sheath and a closed state where the hook is disposed within the sheath.

  17. (Questions)n on phloem biology. 2. Mass flow, molecular hopping, distribution patterns and macromolecular signalling.

    PubMed

    van Bel, Aart J E; Furch, Alexandra C U; Hafke, Jens B; Knoblauch, Michael; Patrick, John W

    2011-10-01

    This review speculates on correlations between mass flow in sieve tubes and the distribution of photoassimilates and macromolecular signals. Since micro- (low-molecular compounds) and macromolecules are withdrawn from, and released into, the sieve-tube sap at various rates, distribution patterns of these compounds do not strictly obey mass-flow predictions. Due to serial release and retrieval transport steps executed by sieve tube plasma membranes, micromolecules are proposed to "hop" between sieve element/companion cell complexes and phloem parenchyma cells under source-limiting conditions (apoplasmic hopping). Under sink-limiting conditions, micromolecules escape from sieve tubes via pore-plasmodesma units and are temporarily stored. It is speculated that macromolecules "hop" between sieve elements and companion cells using plasmodesmal trafficking mechanisms (symplasmic hopping). We explore how differential tagging may influence distribution patterns of macromolecules and how their bidirectional movement could arise. Effects of exudation techniques on the macromolecular composition of sieve-tube sap are discussed. PMID:21889037

  18. Extended Empirical Orthogonal Teleconnection (EEOT) Analysis

    NASA Astrophysics Data System (ADS)

    Eastman, R.; Wu, Q.

    2012-12-01

    Earth System Science (ESS) is particularly concerned with understanding coupled earth systems. With the advent of the Earth Observing System, empirical analysis of coupled systems is now greatly facilitated. However, the conventional means of spectral decomposition through Extended EOF (EEOF) is highly susceptible to the determination of components that mix the character of underlying factors. In this paper we present Extended Empirical Orthogonal Teleconnection (EEOT) analysis as a means to address this issue. EEOT is an extension of Empirical Orthogonal Teleconnection analysis - a regression-based form of spectral decomposition that offers the advantage of a natural and automatic form of rotation. In this extended form where multiple image times series are analyzed simultaneously, EEOT provides an opportunity to search for coupled sources of variability. The technique is illustrated through an analysis of the relationship between anomalies in detrended sea surface temperature, middle tropospheric temperature and lower stratospheric temperature for the 30-year period from 1982-2011. One of the predominant patterns found is a pan-tropical Atmospheric Bridge effect whereby ENSO ocean forcing is propagated throughout the tropical troposphere with feedbacks to the Atlantic and Indian ocean basins.

  19. Affinity Propagation Clustering of Measurements for Multiple Extended Target Tracking

    PubMed Central

    Zhang, Tao; Wu, Renbiao

    2015-01-01

    More measurements are generated by the target per observation interval, when the target is detected by a high resolution sensor, or there are more measurement sources on the target surface. Such a target is referred to as an extended target. The probability hypothesis density filter is considered an efficient method for tracking multiple extended targets. However, the crucial problem of how to accurately and effectively partition the measurements of multiple extended targets remains unsolved. In this paper, affinity propagation clustering is introduced into measurement partitioning for extended target tracking, and the elliptical gating technique is used to remove the clutter measurements, which makes the affinity propagation clustering capable of partitioning the measurement in a densely cluttered environment with high accuracy. The Gaussian mixture probability hypothesis density filter is implemented for multiple extended target tracking. Numerical results are presented to demonstrate the performance of the proposed algorithm, which provides improved performance, while obviously reducing the computational complexity. PMID:26370998

  20. Extended cognition in science communication.

    PubMed

    Ludwig, David

    2014-11-01

    The aim of this article is to propose a methodological externalism that takes knowledge about science to be partly constituted by the environment. My starting point is the debate about extended cognition in contemporary philosophy and cognitive science. Externalists claim that human cognition extends beyond the brain and can be partly constituted by external devices. First, I show that most studies of public knowledge about science are based on an internalist framework that excludes the environment we usually utilize to make sense of science and does not allow the possibility of extended knowledge. In a second step, I argue that science communication studies should adopt a methodological externalism and accept that knowledge about science can be partly realized by external information resources such as Wikipedia.

  1. An Extended Keyword Extraction Method

    NASA Astrophysics Data System (ADS)

    Hong, Bao; Zhen, Deng

    Among numerous Chinese keyword extraction methods, Chinese characteristics were shortly considered. This phenomenon going against the precision enhancement of the Chinese keyword extraction. An extended term frequency based method(Extended TF) is proposed in this paper which combined Chinese linguistic characteristics with basic TF method. Unary, binary and ternary grammars for the candidate keyword extraction as well as other linguistic features were all taken into account. The method establishes classification model using support vector machine. Tests show that the proposed extraction method improved key words precision and recall rate significantly. We applied the key words extracted by the extended TF method into the text file classification. Results show that the key words extracted by the proposed method contributed greatly to raising the precision of text file classification.

  2. Complex-extended Bohmian mechanics.

    PubMed

    Chou, Chia-Chun; Wyatt, Robert E

    2010-04-01

    Complex-extended Bohmian mechanics is investigated by analytically continuing the wave function in polar form into the complex plane. We derive the complex-extended version of the quantum Hamilton-Jacobi equation and the continuity equation in Bohmian mechanics. Complex-extended Bohmian mechanics recovers the standard real-valued Bohmian mechanics on the real axis. The trajectories on the real axis are in accord with the standard real-valued Bohmian trajectories. The trajectories launched away from the real axis never intersect the real axis, and they display symmetry with respect to the real axis. Trajectories display hyperbolic deflection around nodes of the wave function in the complex plane. PMID:20387916

  3. A novel extended state observer.

    PubMed

    Xiong, Shaofeng; Wang, Weihong; Liu, Xiaodong; Chen, Zengqiang; Wang, Sen

    2015-09-01

    A novel extended state observer, which feeds back the output estimation error via both nonlinear and switching terms, is put forward for the first time in this paper. No longer neglecting the lumped uncertainty׳s first time derivative, the problem of disturbance observer design is transformed into the problem of state observer design in the presence of external disturbance. The switching term of the output estimation error is employed to counteract the adverse effect of external disturbance. The newly developed extended state observer provides an attractive solution to the issue of high precision motion control system. Both numerical simulation and experimentation on a speed turntable with temperature box are implemented to verify the performance of the proposed newly developed extended state observer. PMID:26275404

  4. Constrained Stochastic Extended Redundancy Analysis.

    PubMed

    DeSarbo, Wayne S; Hwang, Heungsun; Stadler Blank, Ashley; Kappe, Eelco

    2015-06-01

    We devise a new statistical methodology called constrained stochastic extended redundancy analysis (CSERA) to examine the comparative impact of various conceptual factors, or drivers, as well as the specific predictor variables that contribute to each driver on designated dependent variable(s). The technical details of the proposed methodology, the maximum likelihood estimation algorithm, and model selection heuristics are discussed. A sports marketing consumer psychology application is provided in a Major League Baseball (MLB) context where the effects of six conceptual drivers of game attendance and their defining predictor variables are estimated. Results compare favorably to those obtained using traditional extended redundancy analysis (ERA). PMID:24327066

  5. Adjustable extender for instrument module

    DOEpatents

    Sevec, J.B.; Stein, A.D.

    1975-11-01

    A blank extender module used to mount an instrument module in front of its console for repair or test purposes has been equipped with a rotatable mount and means for locking the mount at various angles of rotation for easy accessibility. The rotatable mount includes a horizontal conduit supported by bearings within the blank module. The conduit is spring-biased in a retracted position within the blank module and in this position a small gear mounted on the conduit periphery is locked by a fixed pawl. The conduit and instrument mount can be pulled into an extended position with the gear clearing the pawl to permit rotation and adjustment of the instrument.

  6. Constrained Stochastic Extended Redundancy Analysis.

    PubMed

    DeSarbo, Wayne S; Hwang, Heungsun; Stadler Blank, Ashley; Kappe, Eelco

    2015-06-01

    We devise a new statistical methodology called constrained stochastic extended redundancy analysis (CSERA) to examine the comparative impact of various conceptual factors, or drivers, as well as the specific predictor variables that contribute to each driver on designated dependent variable(s). The technical details of the proposed methodology, the maximum likelihood estimation algorithm, and model selection heuristics are discussed. A sports marketing consumer psychology application is provided in a Major League Baseball (MLB) context where the effects of six conceptual drivers of game attendance and their defining predictor variables are estimated. Results compare favorably to those obtained using traditional extended redundancy analysis (ERA).

  7. WFRC patrners: our extended family

    USGS Publications Warehouse

    Thorsteinson, Lyman

    2007-01-01

    For more than five decades the Western Fisheries Research Center (WFRC) has worked with partners to provide research findings to managers of aquatic resources. Those partners form an extended family, a network of clients, colleagues, co-investigators, and customers. Our partners include numerous clients in other Department of Interior bureaus such as the U.S. Fish and Wildlife Service, the U.S. Bureau of Reclamation, and the National Park Service. But there is much more--we have partners in other federal agencies, state agencies, and universities. The extended family includes tribal governments, and non-government organizations such as the Nature Conservancy and the Lower Columbia River Estuary Program.

  8. WISE Detection of the Circumstellar Disk Associated with 2MASS J0820-8003 in the η Cha Cluster

    NASA Astrophysics Data System (ADS)

    Simon, M.; Schlieder, Joshua E.; Constantin, Ana-Maria; Silverstein, Michele

    2012-06-01

    The Nearby Young Moving Groups (NYMGs) of stars are ideal for the study of the evolution of circumstellar disks in which planets may form because their ages range from a few Myr to ~100 Myr, about the same as the interval over which planets are thought to form. Their stars are distributed over large regions of the sky. Hence, the Wide Field Infrared Survey Explorer (WISE), which scanned the entire sky in four bands from 3.4 to 22.1 μm, provides a database well suited for the study of members of the NYMGs, particularly those identified after the eras of the IRAS and Spitzer observatories. Here, we report our study of the stars in the epsilon and η Cha, TW Hya, β Pic, Tuc-Hor, and AB Dor NYMGs. The WISE Preliminary Release Source Catalog, which covers 57% of the sky, contains data for 64% of the stars in our search lists. WISE detected the 11.6 and 22.1 μm emission of all the previously known disks except for the coldest one, AU Mic. WISE detected no disks in the Tuc-Hor and AB Dor groups, the two oldest in our sample; the frequency of disks detected by WISE decreases rapidly with the age of the group. WISE detected a circumstellar disk associated with 2M J0820-8003, a pre-main-sequence star with episodic accretion in the ~6 Myr old η Cha cluster. The inner radius of the disk extends close to the star, ~0.02 AU and its luminosity is about a tenth of that of the star. The episodic accretion is probably powered by the circumstellar disk discussed here.

  9. A preliminary systematic search for red-clump stars in Galactic open clusters based on 2mass data

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; Chen, Li; Li, Zhongmu

    2013-02-01

    Red-clump (RC) giants are intermediate-age, core-helium-burning stars. The RC can be used as a standard candle. In particular, the small variance of the RC's K-band intrinsic luminosity and its weak dependence on chemical composition and age make it an extremely useful distance indicator. In this paper, we use 2mass data to search for RC stars in a sample of 60 Galactic open clusters with known reddening, ages, and distances, and obtain an average value for the RC's absolute K s-band magnitude, M K s = -1.72 +/- 0.17 mag.

  10. Lightweight extendable and retractable pole

    DOEpatents

    Warren, J.L.; Brandt, J.E.

    1994-08-02

    A lightweight extendable and retractable telescopic pole is disclosed comprising a plurality of non-metallic telescoping cylinders with sliding and sealing surfaces between the cylinders, a first plug member on the upper end of the smallest cylinder, and a second plug member on the lower end of the largest cylinder, whereby fluid pressure admitted to the largest cylinder will cause the telescoping cylinders to slide relative to one another causing the pole to extend. An elastomeric member connects the first plug member with one of the intermediate cylinders to urge the cylinders back into a collapsed position when the fluid pressure in the cylinders is vented. Annular elastomer members are provided which seal one cylinder to another when the pole is fully extended and further serve to provide a cushion to prevent damage to the cylinders when the pole is urged back into its retractable position by the elastomeric members and the venting of the pressure. A value mechanism associated with the pole is provided to admit a fluid under pressure to the interior of the telescoping cylinders of the pole while pressurizing a pressure relief port having an opening larger than the inlet port in a closed position whereby removal of the pressure on the relief port will cause the relief port to open to quickly lower the pressure in the interior of the telescoping cylinders to thereby assist in the rapid retraction of the extended pole. 18 figs.

  11. Lightweight extendable and retractable pole

    DOEpatents

    Warren, John L.; Brandt, James E.

    1994-01-01

    A lightweight extendable and retractable telescopic pole is disclosed comprising a plurality of non-metallic telescoping cylinders with sliding and sealing surfaces between the cylinders, a first plug member on the upper end of the smallest cylinder, and a second plug member on the lower end of the largest cylinder, whereby fluid pressure admitted to the largest cylinder will cause the telescoping cylinders to slide relative to one another causing the pole to extend. An elastomeric member connects the first plug member with one of the intermediate cylinders to urge the cylinders back into a collapsed position when the fluid pressure in the cylinders is vented. Annular elastomer members are provided which seal one cylinder to another when the pole is fully extended and further serve to provide a cushion to prevent damage to the cylinders when the pole is urged back into its retractable position by the elastomeric members and the venting of the pressure. A value mechanism associated with the pole is provided to admit a fluid under pressure to the interior of the telescoping cylinders of the pole while pressurizing a pressure relief port having an opening larger than the inlet port in a closed position whereby removal of the pressure on the relief port will cause the relief port to open to quickly lower the pressure in the interior of the telescoping cylinders to thereby assist in the rapid retraction of the extended pole.

  12. Engage, Enhance, and Extend Learning!

    ERIC Educational Resources Information Center

    Keren-Kolb, Liz

    2013-01-01

    Educators often say that technology is more than a gimmick or add-on, and that it should engage, enhance, or extend learning in ways that traditional tools do not. Yet they seldom stop to define these terms, and they can be confusing, especially for teachers and preservice teachers. Recently, while collaborating on an English language arts and…

  13. Extended Duration Orbiter Medical Project

    NASA Technical Reports Server (NTRS)

    Leach, C. S.; Pool, S. L.; Sawin, C. F.; Nicogossian, A. E.

    1990-01-01

    The Extended Duration Orbiter (EDO) program addresses a need for more time to perform experiments and other tasks during Space Shuttle missions. As a part of this program, the Extended Duration Orbiter Medical Project (EDOMP) has been instituted to obtain information about physiologic effects of extending mission duration and the effectiveness of countermeasures against factors that might compromise crew health, safety, or performance on extended-duration missions. Only those investigations that address and characterize operational problems, develop countermeasures, or evaluate the effectiveness of countermeasures will be pursued. The EDOMP investigations will include flight-associated Detailed Supplementary Objectives as well as ground-based studies simulating the influence of microgravity. Investigator teams have been formed in the following areas: biomedical physiology, cardiovascular and fluid/electrolyte physiology, environmental health, muscle and exercise physiology, and neurophysiology. Major operational questions must be answered in each of these areas, and investigations have been designed to answer them. The EDO program will proceed only after countermeasures have been shown to be effective in preventing or mitigating the adverse changes they have been designed to attenuate. The program is underway and will continue on each Shuttle flight as the manifest builds toward a 16-day orbital flight.

  14. Extended range chemical sensing apparatus

    DOEpatents

    Hughes, Robert C.; Schubert, W. Kent

    1994-01-01

    An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.

  15. A CROSS-MATCH OF 2MASS AND SDSS. II. PECULIAR L DWARFS, UNRESOLVED BINARIES, AND THE SPACE DENSITY OF T DWARF SECONDARIES

    SciTech Connect

    Geissler, Kerstin; Metchev, Stanimir; Kirkpatrick, J. Davy; Berriman, G. Bruce; Looper, Dagny

    2011-05-01

    We present the completion of a program to cross-correlate the Sloan Digital Sky Survey Data Release 1 (SDSS DR1) and Two-Micron All-Sky Survey (2MASS) Point Source Catalog in search for extremely red L and T dwarfs. The program was initiated by Metchev and collaborators, who presented the findings on all newly identified T dwarfs in SDSS DR1 and estimated the space density of isolated T0-T8 dwarfs in the solar neighborhood. In the current work, we present most of the L dwarf discoveries. Our red-sensitive (z - J {>=} 2.75 mag) cross-match proves to be efficient in detecting peculiarly red L dwarfs, adding two new ones, including one of the reddest known L dwarfs. Our search also nets a new peculiarly blue L7 dwarf and, surprisingly, two M8 dwarfs. We further broaden our analysis to detect unresolved binary L or T dwarfs through spectral template fitting to all L and T dwarfs presented here and in the earlier work by Metchev and collaborators. We identify nine probable binaries, six of which are new and eight harbor likely T dwarf secondaries. We combine this result with current knowledge of the mass ratio distribution and frequency of substellar companions to estimate an overall space density of 0.005-0.05 pc{sup -3} for individual T0-T8 dwarfs.

  16. CARMA INTERFEROMETRIC OBSERVATIONS OF 2MASS J044427+2512: THE FIRST SPATIALLY RESOLVED OBSERVATIONS OF THERMAL EMISSION OF A BROWN DWARF DISK

    SciTech Connect

    Ricci, L.; Isella, A.; Carpenter, J. M.; Testi, L.

    2013-02-20

    We present CARMA 1.3 mm continuum data of the disk surrounding the young brown dwarf 2MASS J044427+2512 in the Taurus molecular cloud. The high angular resolution of the CARMA observations (0.''16) allows us to spatially resolve for the first time the thermal emission from dust around a brown dwarf. We analyze the interferometric visibilities and constrain the disk outer radius adopting disk models with power-law radial profiles of the dust surface density. In the case of a power-law index {<=}1, we obtain a disk radius in the range of about 15-30 AU, while larger disks are inferred for steeper radial profiles. By combining this information on the disk spatial extent with the sub-mm spectral index of this source, we find conclusive evidence for mm-sized grains, or larger, in this brown dwarf disk. We discuss the implications of our results on the models of dust evolution in protoplanetary disks and brown dwarf formation.

  17. Extended recency effect extended: blocking, presentation mode, and retention interval.

    PubMed

    Glidden, L M; Pawelski, C; Mar, H; Zigman, W

    1979-07-01

    The effect of blocking of stimulus items on the free recall of EMR adolescents was examined. In Experiment 1 a multitrial free-recall list of 15 pictures was presented either simultaneously in groups of 3, or sequentially, one at a time. Consistent ordering was used in both conditions, so that on each trial, each item in each set of 3 pictures was presented contiguously with the other 2 items from that set. In addition, recall came immediately or after a filled or unfilled delay of 24.5 seconds. Results showed that simultaneous presentation led to higher recall, subjective organization, and clustering than did sequential presentation, but analysis of serial-position curves showed a much reduced extended recency effect in comparison with previous studies. Experiment 2 was designed to determine whether the cause of the reduced extended recency was the use of pictures rather than words as stimuli. Stimuli were presented either as pictures, as pictures with auditory labels, or as words with auditory labels, with both simultaneous and consistent ordering for all conditions. Results indicated a strong extended recency effect for all groups, eliminating presentation mode as a causal factor in the data of Experiment 1. We concluded that blocking leads to increased organization and recall over a variety of presentation modes, rates, and block sizes.

  18. FIRE I - Extended Time Observations Data Sets

    Atmospheric Science Data Center

    2013-08-01

    FIRE I - Extended Time Observations Data Sets First ISCCP Regional Experiment (FIRE) I - Extended Time Observations were conducted in Utah. Relevant Documents:  FIRE Project Guide FIRE I - Extended Time Observations Home Page SCAR-B Block:  ...

  19. Extended-Synaptotagmins (E-Syts); the extended story.

    PubMed

    Herdman, Chelsea; Moss, Tom

    2016-05-01

    The Extended-Synaptotagmin (E-Syt) membrane proteins were only recently discovered, but have already been implicated in a range of interrelated cellular functions, including calcium and receptor signaling, and membrane lipid transport. However, despite their evolutionary conservation and detailed studies of their molecular actions, we still have little idea of how and when these proteins are required in cellular and organism physiology. Here we review our present understanding of the E-Syts and discuss the molecular functions and in vivo requirements for these proteins. PMID:26926095

  20. Relic gravitational waves and extended inflation

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.; Wilczek, Frank

    1990-01-01

    In extended inflation, a new version of inflation where the transition from the false-vacuum phase to a radiation-dominated Universe is accomplished by bubble nucleation and percolation, bubble collisions supply a potent-and potentially detectable-source of gravitational waves. The present energy density in relic gravity waves from bubble collisions is expected to be about 10(exp -5) of closure density-many orders of magnitude greater than that of the gravity waves produced by quantum fluctuations. Their characteristic wavelength depends upon the reheating temperature T(sub RH): lambda is approximately 10(exp 4) cm (10(exp 14) GeV/T(sub RH)). If large numbers of black holes are produced, a not implausible outcome, they will evaporate producing comparable amounts of shorter wavelength waves, lambda is approximately 10(exp -6) cm (T(sub RH)/10(exp 14) GeV).

  1. Affordances and the musically extended mind

    PubMed Central

    Krueger, Joel

    2014-01-01

    I defend a model of the musically extended mind. I consider how acts of “musicking” grant access to novel emotional experiences otherwise inaccessible. First, I discuss the idea of “musical affordances” and specify both what musical affordances are and how they invite different forms of entrainment. Next, I argue that musical affordances – via soliciting different forms of entrainment – enhance the functionality of various endogenous, emotion-granting regulative processes, drawing novel experiences out of us with an expanded complexity and phenomenal character. I argue that music therefore ought to be thought of as part of the vehicle needed to realize these emotional experiences. I appeal to different sources of empirical work to develop this idea. PMID:24432008

  2. Autopoiesis + extended cognition + nature = can buildings think?

    PubMed Central

    Dollens, Dennis

    2015-01-01

    To incorporate metabolic, bioremedial functions into the performance of buildings and to balance generative architecture's dominant focus on computational programming and digital fabrication, this text first discusses hybridizing Maturana and Varela's biological theory of autopoiesis with Andy Clark's hypothesis of extended cognition. Doing so establishes a procedural protocol to research biological domains from which design could source data/insight from biosemiotics, sensory plants, and biocomputation. I trace computation and botanic simulations back to Alan Turing's little-known 1950s Morphogenetic drawings, reaction-diffusion algorithms, and pioneering artificial intelligence (AI) in order to establish bioarchitecture's generative point of origin. I ask provocatively, Can buildings think? as a question echoing Turing's own, "Can machines think?" PMID:26478784

  3. Open source molecular modeling.

    PubMed

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io.

  4. Open source molecular modeling.

    PubMed

    Pirhadi, Somayeh; Sunseri, Jocelyn; Koes, David Ryan

    2016-09-01

    The success of molecular modeling and computational chemistry efforts are, by definition, dependent on quality software applications. Open source software development provides many advantages to users of modeling applications, not the least of which is that the software is free and completely extendable. In this review we categorize, enumerate, and describe available open source software packages for molecular modeling and computational chemistry. An updated online version of this catalog can be found at https://opensourcemolecularmodeling.github.io. PMID:27631126

  5. Improving and Extending Rural Library Services in Idaho.

    ERIC Educational Resources Information Center

    Weatherby, James B.; And Others

    This study of rural libraries in Idaho was designed to identify appropriate alternative local revenue sources to support library services as well as ways of improving the coordination and delivery of library services in the state and extending library access to unserved areas. Data were gathered from U.S. Bureau of the Census reports and special…

  6. Group-theoretical construction of extended baryon operators

    SciTech Connect

    S. Basak; R. Edwards; R. Fiebig; G. T. Fleming; U. M. Heller; C. Morningstar; D. Richards; I. Sato; S. Wallace

    2004-06-01

    The design and implementation of large sets of spatially extended baryon operators for use in lattice simulations are described. The operators are constructed to maximize overlaps with the low-lying states of interest, while minimizing the number of sources needed in computing the required quark propagators.

  7. THE HYPERACTIVE L DWARF 2MASS J13153094-2649513: CONTINUED EMISSION AND A BROWN DWARF COMPANION

    SciTech Connect

    Burgasser, Adam J.; Sitarski, Breann N.; Logsdon, Sarah E.; Gelino, Christopher R.; Perrin, Marshall D.

    2011-09-20

    We report new observations of the unusually active, high proper motion L5e dwarf 2MASS J13153094-2649513. Optical spectroscopy with Magellan/MagE reveals persistent nonthermal emission, with narrow H I Balmer, Na I and K I lines all observed in emission. Low-resolution near-infrared spectroscopy with the Infrared Telescope Facility/SpeX Spectrograph indicates the presence of a low-temperature companion, which is resolved through multi-epoch laser guide star adaptive optics imaging at the W. M. Keck Observatory. The co-moving companion is separated by 338 {+-} 4 mas, and its relative brightness ({Delta}K{sub s} = 5.09 {+-} 0.10) makes this system the second-most-extreme flux ratio very-low-mass binary identified to date. Resolved near-infrared spectroscopy with Keck/OSIRIS identifies the companion as a T7 dwarf. The absence of Li I absorption in combined-light optical spectroscopy constrains the system age to {approx}>0.8-1.0 Gyr, while the system's kinematics and unusually low mass ratio (M{sub 2}/M{sub 1} = 0.3-0.6) suggest that it is even older. A coevality test of the components also indicates an older age, but reveals discrepancies between evolutionary and atmosphere model fits of the secondary, which are likely attributable to poor reproduction of its near-infrared spectrum. With a projected separation of 6.6 {+-} 0.9 AU, the 2MASS J1315-2649 system is too widely separated for mass exchange or magnetospheric interactions to be powering its persistent nonthermal emission. Rather, the emission is probably chromospheric in nature, consistent with an inversion in the age-activity relation in which strong magnetic fields are maintained by relatively old and massive ultracool dwarfs.

  8. Electromagnetic interactions of extended nucleons

    SciTech Connect

    Ohta, K. )

    1989-09-01

    An electromagnetic current operator is deduced from the most general form of the extended pion-nucleon vertex function using the minimal substitution prescription. It is proved that the sum of the obtained current operator and the isolated-pole contribution satisfies the Ward-Takahashi identity derived for the pion photoproduction. The minimal-coupling interaction is applied to the calculation of the one-pion exchange current regularized by the pion-nucleon form factors. It is found that the one-pion exchange current operator including hadronic and electromagnetic form factors satisfies the Ward-Takahashi equation for the nucleon-nucleon interaction.

  9. Renormalization of Extended QCD2

    NASA Astrophysics Data System (ADS)

    Fukaya, Hidenori; Yamamura, Ryo

    2015-10-01

    Extended QCD (XQCD), proposed by Kaplan [D. B. Kaplan, arXiv:1306.5818], is an interesting reformulation of QCD with additional bosonic auxiliary fields. While its partition function is kept exactly the same as that of original QCD, XQCD naturally contains properties of low-energy hadronic models. We analyze the renormalization group flow of 2D (X)QCD, which is solvable in the limit of a large number of colors N_c, to understand what kind of roles the auxiliary degrees of freedom play and how the hadronic picture emerges in the low-energy region.

  10. Extending earthquakes' reach through cascading.

    PubMed

    Marsan, David; Lengliné, Olivier

    2008-02-22

    Earthquakes, whatever their size, can trigger other earthquakes. Mainshocks cause aftershocks to occur, which in turn activate their own local aftershock sequences, resulting in a cascade of triggering that extends the reach of the initial mainshock. A long-lasting difficulty is to determine which earthquakes are connected, either directly or indirectly. Here we show that this causal structure can be found probabilistically, with no a priori model nor parameterization. Large regional earthquakes are found to have a short direct influence in comparison to the overall aftershock sequence duration. Relative to these large mainshocks, small earthquakes collectively have a greater effect on triggering. Hence, cascade triggering is a key component in earthquake interactions.

  11. 38 CFR 21.57 - Extended evaluation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Extended evaluation. 21... Initial and Extended Evaluation § 21.57 Extended evaluation. (a) Purpose. The purpose of an extended evaluation for a veteran with a serious employment handicap is to determine the current feasibility of...

  12. Extended suicide with a pet.

    PubMed

    Cooke, Brian K

    2013-01-01

    The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases. PMID:24051598

  13. Extended Duration Orbiter Medical Project

    NASA Technical Reports Server (NTRS)

    Sawin, Charles F. (Editor); Taylor, Gerald R. (Editor); Smith, Wanda L. (Editor); Brown, J. Travis (Technical Monitor)

    1999-01-01

    Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

  14. Implications of Extended Solar Minima

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Davis, J. M.

    2009-01-01

    Since the discovery of periodicity in the solar cycle, the historical record of sunspot number has been carefully examined, attempting to make predictions about the next cycle. Much emphasis has been on predicting the maximum amplitude and length of the next cycle. Because current space-based and suborbital instruments are designed to study active phenomena, there is considerable interest in estimating the length and depth of the current minimum. We have developed criteria for the definition of a minimum and applied it to the historical sunspot record starting in 1749. In doing so, we find that 1) the current minimum is not yet unusually long and 2) there is no obvious way of predicting when, using our definition, the current minimum may end. However, by grouping the data into 22- year cycles there is an interesting pattern of extended minima that recurs every fourth or fifth 22-year cycle. A preliminary comparison of this pattern with other records, suggests the possibility of a correlation between extended minima and lower levels of solar irradiance.

  15. Extended Operation of Stirling Convertors

    NASA Technical Reports Server (NTRS)

    Roth, Mary Ellen; Schreiber, Jeffery G.; Pepper, Stephen V.

    2004-01-01

    A high-efficiency 110 W Stirling Radioisotope Generator 110 (SRG110) is being developed for potential NASA exploration missions. The SRG system efficiency is greater than 20%, making it an attractive candidate power system for deep space missions and unmanned rovers. The Department of Energy SRG110 Project team consists of the System Integrator, Lockheed Martin (LM), Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). One of the GRC roles is to provide Independent Verification and Validation of the Stirling TDC s. At the request of LM, a part of this effort includes the Extended Operation of the TDC s in the dynamically balanced dual-opposed configuration. Performance data of Stirling Convertors over time is required to demonstrate that an SRG110 can meet long-duration mission requirements. A test plan and test system were developed to evaluate TDC s #13 and #14 steady-state performance for a minimum of 5000 hours. Hardware, software and TDC preparation processes were developed to support this test and insure safe, round-the-clock operation of the TDC s. This paper will discuss the design and development, and status of the Extended Operation Test.

  16. Extended Operation of Stirling Convertors

    NASA Technical Reports Server (NTRS)

    Roth, Mary Ellen; Schreiber, Jeffrey G.; Pepper, Stephen V.

    2004-01-01

    A high-efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed for potential NASA exploration missions. The SRG system efficiency is greater than 20%, making it an attractive candidate power system for deep space missions and unmanned rovers. The Department of Energy SRG110 Project team consists of the System Integrator, Lockheed Martin (LM), Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). One of the GRC roles is to provide Independent Verification and Validation of the Stirling TDC's. At the request of LM, a part of this effort includes the extended operation of the TDC's in the dynamically balanced dual-opposed configuration. Performance data of the Stirling Converters over time is required to demonstrate that an SRG110 can meet long-duration mission requirements. A test plan and test system were developed to evaluate TDC's #13 and #14 steady-state performance for a minimum of 5000 hours and insure safe, round-the-clock operation of the TDC's. This paper will discuss the design and development, and status of the Extended Operation Test.

  17. Reasoning over Extended ER Models

    NASA Astrophysics Data System (ADS)

    Artale, A.; Calvanese, D.; Kontchakov, R.; Ryzhikov, V.; Zakharyaschev, M.

    We investigate the computational complexity of reasoning over various fragments of the Extended Entity-Relationship (EER) language, which includes a number of constructs: isa between entities and relationships, disjointness and covering of entities and relationships, cardinality constraints for entities in relationships and their refinements as well as multiplicity constraints for attributes. We extend the known ExpTime-completeness result for UML class diagrams [5] and show that reasoning over EER diagrams with isa between relationships is ExpTime-complete even without relationship covering. Surprisingly, reasoning becomes NP-complete when we drop isa between relationships (while still allowing all types of constraints on entities). If we further omit disjointness and covering over entities, reasoning becomes polynomial. Our lower complexity bound results are proved by direct reductions, while the upper bounds follow from the correspondences with expressive variants of the description logic DL-Lite, which we establish in this paper. These correspondences also show the usefulness of DL-Lite as a language for reasoning over conceptual models and ontologies.

  18. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, W.T.

    1992-06-16

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

  19. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, William T.

    1992-01-01

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler.

  20. The Brera Multi-scale Wavelet ROSAT HRI source catalogue

    NASA Astrophysics Data System (ADS)

    Panzera, M. R.; Campana, S.; Covino, S.; Lazzati, D.; Mignani, R. P.; Moretti, A.; Tagliaferri, G.

    2003-02-01

    We present the Brera Multi-scale Wavelet ROSAT HRI source catalogue (BMW-HRI) derived from all ROSAT HRI pointed observations with exposure times longer than 100 s available in the ROSAT public archives. The data were analyzed automatically using a wavelet detection algorithm suited to the detection and characterization of both point-like and extended sources. This algorithm is able to detect and disentangle sources in very crowded fields and/or in the presence of extended or bright sources. Images have been also visually inspected after the analysis to ensure verification. The final catalogue, derived from 4303 observations, consists of 29 089 sources detected with a detection probability of >=4.2 sigma . For each source, the primary catalogue entries provide name, position, count rate, flux and extension along with the relative errors. In addition, results of cross-correlations with existing catalogues at different wavelengths (FIRST, IRAS, 2MASS and GSC2) are also reported. Some information is available on the web via the DIANA Interface. As an external check, we compared our catalogue with the previously available ROSHRICAT catalogue (both in its short and long versions) and we were able to recover, for the short version, ~ 90% of the entries. We computed the sky coverage of the entire HRI data set by means of simulations. The complete BMW-HRI catalogue provides a sky coverage of 732 deg2 down to a limiting flux of ~ 10-12 erg s-1 cm-2 and of 10 deg2 down to ~ 10-14 erg s-1 cm-2. We were able to compute the cosmological log(N)-log(S) distribution down to a flux of =~ 1.2 x 10-14 erg s-1 cm-2. The catalogue is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/399/351

  1. Hamiltonian dynamics of extended objects

    NASA Astrophysics Data System (ADS)

    Capovilla, R.; Guven, J.; Rojas, E.

    2004-12-01

    We consider relativistic extended objects described by a reparametrization-invariant local action that depends on the extrinsic curvature of the worldvolume swept out by the object as it evolves. We provide a Hamiltonian formulation of the dynamics of such higher derivative models which is motivated by the ADM formulation of general relativity. The canonical momenta are identified by looking at boundary behaviour under small deformations of the action; the relationship between the momentum conjugate to the embedding functions and the conserved momentum density is established. The canonical Hamiltonian is constructed explicitly; the constraints on the phase space, both primary and secondary, are identified and the role they play in the theory is described. The multipliers implementing the primary constraints are identified in terms of the ADM lapse and shift variables and Hamilton's equations are shown to be consistent with the Euler Lagrange equations.

  2. Extending Medicare immunosuppressive medication coverage.

    PubMed

    Beaubrun, Anne Christine

    2012-02-01

    African Americans and the poor are at a high risk of suffering from kidney disease and are at an extreme disadvantage when it comes to obtaining the resources needed to maintain a functioning kidney post-transplant. Medicare currently covers 80% of the cost of immunosuppressive therapy for up to three years following a Medicare-covered transplant for patients whose Medicare entitlement was based solely on their end-stage renal disease diagnosis. Adequate insurance coverage has the potential to prevent graft failure and retransplantation resulting from cost-related immunosuppressive medication nonadherence. Given the multifactorial nature of medication nonadherence, extending insurance coverage in an attempt to reduce graft failures should be coupled with intensive interventions to prevent the socioeconomic and various other factors associated with medication nonadherence. Lifetime Medicare coverage for all kidney-transplant recipients, coupled with medication adherence promotion, has the potential to minimize poor outcomes associated with graft failure, especially among minorities and the impoverished.

  3. Extended uncertainty from first principles

    NASA Astrophysics Data System (ADS)

    Costa Filho, Raimundo N.; Braga, João P. M.; Lira, Jorge H. S.; Andrade, José S.

    2016-04-01

    A translation operator acting in a space with a diagonal metric is introduced to describe the motion of a particle in a quantum system. We show that the momentum operator and, as a consequence, the uncertainty relation now depend on the metric. It is also shown that, for any metric expanded up to second order, this formalism naturally leads to an extended uncertainty principle (EUP) with a minimum momentum dispersion. The Ehrenfest theorem is modified to include an additional term related to a tidal force arriving from the space curvature introduced by the metric. For one-dimensional systems, we show how to map a harmonic potential to an effective potential in Euclidean space using different metrics.

  4. Extended mission life support systems

    NASA Technical Reports Server (NTRS)

    Quattrone, P. D.

    1985-01-01

    Extended manned space missions which include interplanetary missions require regenerative life support systems. Manned mission life support considerations are placed in perspective and previous manned space life support system technology, activities and accomplishments in current supporting research and technology (SR&T) programs are reviewed. The life support subsystem/system technologies required for an enhanced duration orbiter (EDO) and a space operations center (SOC), regenerative life support functions and technology required for manned interplanetary flight vehicles, and future development requirements are outlined. The Space Shuttle Orbiters (space transportation system) is space cabin atmosphere is maintained at Earth ambient pressure of 14.7 psia (20% O2 and 80% N2). The early Shuttle flights will be seven-day flights, and the life support system flight hardware will still utilize expendables.

  5. Learning Extended Finite State Machines

    NASA Technical Reports Server (NTRS)

    Cassel, Sofia; Howar, Falk; Jonsson, Bengt; Steffen, Bernhard

    2014-01-01

    We present an active learning algorithm for inferring extended finite state machines (EFSM)s, combining data flow and control behavior. Key to our learning technique is a novel learning model based on so-called tree queries. The learning algorithm uses the tree queries to infer symbolic data constraints on parameters, e.g., sequence numbers, time stamps, identifiers, or even simple arithmetic. We describe sufficient conditions for the properties that the symbolic constraints provided by a tree query in general must have to be usable in our learning model. We have evaluated our algorithm in a black-box scenario, where tree queries are realized through (black-box) testing. Our case studies include connection establishment in TCP and a priority queue from the Java Class Library.

  6. Extended MHD Simulations of Spheromaks

    NASA Astrophysics Data System (ADS)

    Howell, E. C.; Sovinec, C. R.

    2012-10-01

    Nonlinear extended MHD simulations of a spheromak in a cylindrical flux conserver are performed using the NIMROD code (JCP 195, 2004). An idealized series of simulations starting from a Grad-Shafranov equilibrium and small non-axisymmetric perturbations are performed to model the sustained decay phase. The resulting confinement leads to steep resistivity gradients. Strong current gradients develop, driving tearing modes that dominate the evolution of the spheromak. Absent in these simulations are the remains of n=1 fluctuations created during the formation process. A second series of simulations start from vacuum fields and model the full spheromak evolution, including the formation process where the n=1 fluctuations dominate. To understand the role of pressure driven instabilities in the evolution of the spheromak, a numerical diagnostic is developed to calculate the Mercier stability criterion from the axisymmetric fields.

  7. Dicyanometallates as Model Extended Frameworks

    PubMed Central

    2016-01-01

    We report the structures of eight new dicyanometallate frameworks containing molecular extra-framework cations. These systems include a number of hybrid inorganic–organic analogues of conventional ceramics, such as Ruddlesden–Popper phases and perovskites. The structure types adopted are rationalized in the broader context of all known dicyanometallate framework structures. We show that the structural diversity of this family can be understood in terms of (i) the charge and coordination preferences of the particular metal cation acting as framework node, and (ii) the size, shape, and extent of incorporation of extra-framework cations. In this way, we suggest that dicyanometallates form a particularly attractive model family of extended frameworks in which to explore the interplay between molecular degrees of freedom, framework topology, and supramolecular interactions. PMID:27057759

  8. Stellar structures in Extended Gravity

    NASA Astrophysics Data System (ADS)

    Capozziello, S.; De Laurentis, M.

    2016-09-01

    Stellar structures are investigated by considering the modified Lané-Emden equation coming out from Extended Gravity. In particular, this equation is obtained in the Newtonian limit of f ( R) -gravity by introducing a polytropic relation between the pressure and the density into the modified Poisson equation. The result is an integro-differential equation, which, in the limit f ( R) → R , becomes the standard Lané-Emden equation usually adopted in the stellar theory. We find the radial profiles of gravitational potential by solving for some values of the polytropic index. The solutions are compatible with those coming from General Relativity and could be physically relevant in order to address peculiar and extremely massive objects.

  9. Extended Klein edges in graphene.

    PubMed

    He, Kuang; Robertson, Alex W; Lee, Sungwoo; Yoon, Euijoon; Lee, Gun-Do; Warner, Jamie H

    2014-12-23

    Graphene has three experimentally confirmed periodic edge terminations, zigzag, reconstructed 5-7, and arm-chair. Theory predicts a fourth periodic edge of graphene called the extended Klein (EK) edge, which consists of a series of single C atoms protruding from a zigzag edge. Here, we confirm the existence of EK edges in both graphene nanoribbons and on the edge of bulk graphene using atomic resolution imaging by aberration-corrected transmission electron microscopy. The formation of the EK edge stems from sputtering and reconstruction of the zigzag edge. Density functional theory reveals minimal energy for EK edge reconstruction and bond distortion both in and out of plane, supporting our TEM observations. The EK edge can now be included as the fourth member of observed periodic edge structures in graphene.

  10. Extended optical model for fission

    DOE PAGES

    Sin, M.; Capote, R.; Herman, M. W.; Trkov, A.

    2016-03-07

    A comprehensive formalism to calculate fission cross sections based on the extension of the optical model for fission is presented. It can be used for description of nuclear reactions on actinides featuring multi-humped fission barriers with partial absorption in the wells and direct transmission through discrete and continuum fission channels. The formalism describes the gross fluctuations observed in the fission probability due to vibrational resonances, and can be easily implemented in existing statistical reaction model codes. The extended optical model for fission is applied for neutron induced fission cross-section calculations on 234,235,238U and 239Pu targets. A triple-humped fission barrier ismore » used for 234,235U(n,f), while a double-humped fission barrier is used for 238U(n,f) and 239Pu(n,f) reactions as predicted by theoretical barrier calculations. The impact of partial damping of class-II/III states, and of direct transmission through discrete and continuum fission channels, is shown to be critical for a proper description of the measured fission cross sections for 234,235,238U(n,f) reactions. The 239Pu(n,f) reaction can be calculated in the complete damping approximation. Calculated cross sections for 235,238U(n,f) and 239Pu(n,f) reactions agree within 3% with the corresponding cross sections derived within the Neutron Standards least-squares fit of available experimental data. Lastly, the extended optical model for fission can be used for both theoretical fission studies and nuclear data evaluation.« less

  11. Extending the utility of a radioactive material package

    SciTech Connect

    Abramczyk, G.; Nathan, S.; Loftin, B.; Bellamy, S.

    2015-06-04

    Once a package has been certified for the transportation of DOT Hazard Class 7 – Radioactive Material in compliance with the requirements of 10 CFR 71, it is often most economical to extend its utility through the addition of content-specific configuration control features or the addition of shielding materials. The SRNL Model 9977 Package’s authorization was expanded from its original single to twenty contents in this manner; and most recently, the 9977 was evaluated for a high-gamma source content. This paper discusses the need for and the proposed shielding modifications to the package for extending the utility of the package for this purpose.

  12. The Hyperactive L Dwarf 2MASS J13153094-2649513: Continued Emission and a Brown Dwarf Companion

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Sitarski, Breann N.; Gelino, Christopher R.; Logsdon, Sarah E.; Perrin, Marshall D.

    2011-09-01

    We report new observations of the unusually active, high proper motion L5e dwarf 2MASS J13153094-2649513. Optical spectroscopy with Magellan/MagE reveals persistent nonthermal emission, with narrow H I Balmer, Na I and K I lines all observed in emission. Low-resolution near-infrared spectroscopy with the Infrared Telescope Facility/SpeX Spectrograph indicates the presence of a low-temperature companion, which is resolved through multi-epoch laser guide star adaptive optics imaging at the W. M. Keck Observatory. The co-moving companion is separated by 338 ± 4 mas, and its relative brightness (ΔKs = 5.09 ± 0.10) makes this system the second-most-extreme flux ratio very-low-mass binary identified to date. Resolved near-infrared spectroscopy with Keck/OSIRIS identifies the companion as a T7 dwarf. The absence of Li I absorption in combined-light optical spectroscopy constrains the system age to gsim0.8-1.0 Gyr, while the system's kinematics and unusually low mass ratio (M 2/M 1 = 0.3-0.6) suggest that it is even older. A coevality test of the components also indicates an older age, but reveals discrepancies between evolutionary and atmosphere model fits of the secondary, which are likely attributable to poor reproduction of its near-infrared spectrum. With a projected separation of 6.6 ± 0.9 AU, the 2MASS J1315-2649 system is too widely separated for mass exchange or magnetospheric interactions to be powering its persistent nonthermal emission. Rather, the emission is probably chromospheric in nature, consistent with an inversion in the age-activity relation in which strong magnetic fields are maintained by relatively old and massive ultracool dwarfs. 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, and made possible by the generous financial support of the W. M. Keck

  13. The Brera multi-scale wavelet Chandra survey. I. Serendipitous source catalogue

    NASA Astrophysics Data System (ADS)

    Romano, P.; Campana, S.; Mignani, R. P.; Moretti, A.; Mottini, M.; Panzera, M. R.; Tagliaferri, G.

    2008-09-01

    We present the BMW-Chandra source catalogue drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10 ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterise both point-like and extended sources, we identified 21 325 sources. Among them, 16 758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes our catalogue the largest compilation of Chandra sources to date. The 0.5-10 keV absorption corrected fluxes of these sources range from ˜3× 10-16 to 9×10-12 erg cm-2 s-1 with a median of 7× 10-15 erg cm-2 s-1. The catalogue consists of count rates and relative errors in three energy bands (total, 0.5-7 keV; soft, 0.5-2 keV; and hard, 2-7 keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the extension of the source. We include information drawn from the headers of the original files, as well, and extracted source counts in four additional energy bands, SB1 (0.5-1 keV), SB2 (1-2 keV), HB1 (2-4 keV), and HB2 (4-7 keV). We computed the sky coverage for the full catalogue and for a subset at high Galactic latitude (mid b mid > 20°). The complete catalogue provides a sky coverage in the soft band (0.5-2 keV, S/N =3) of 8 deg2 at a limiting flux of ˜10-13 erg cm-2 s-1, and 2 deg2 at a limiting flux of ˜10-15 erg cm-2 s-1. Furthermore, we present the results of the cross-match with existing catalogues at different wavelengths (FIRST, IRAS, 2MASS, GSC2, and ChaMP). The total numbers of matches with the FIRST, IRASPSC, 2MASS, and GSC2 catalogues obtained after a closest-distance selection are 13, 87, 6700, and 4485, respectively. The catalogue is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130

  14. Modeling extended fluid objects in general relativity

    NASA Astrophysics Data System (ADS)

    Schiff, Conrad

    The purpose of this dissertation is to introduce and explore the notion of modeling extended fluid objects in numerical general relativity. These extended fluid objects, called Fat Particles, are proxies for compact hydrodynamic objects. Unlike full hydrodynamic models, we make the approximation that the details of the matter distribution are riot as important as the gross motion of the Fat Particles center of mass and its contribution to the gravitational field. Thus we provide a semi-analytic model of matter for numerical simulations of Einstein's equations, which may help in modeling gravitational radiation from candidate sources. Our approach to carrying out these investigations is to begin with a continuum variational principle, which yields the desired hydrodynamic and gravitational equations for ideal fluids. Following our analysis of the related numerical technique, Smoothed Particle Hydrodynamics (SPH), we apply a set of discretization and smoothing rules to obtain a discrete action. Subsequent variations yield the Fat Particle equations. Our analysis of a classical ideal fluid demonstrated that a Newtonian Fat Particle is capable of remaining at rest while generating its own gravitational field. We then developed analogous principles for describing relativistic ideal fluids in both covariant and ADM 3+1 forms. Using these principles, we developed analytic and numerical results from relativistic Fat Particle theory. We began with the Subscribe Only model, in which a Fat Particle of negligible mass moves in a fixed background metric. Corrections to its motion due to the extended nature of the Fat Particle, are obtained by summing metric contributions over its volume. We find a universal scaling law that describes the phase shift, relative to a test particle, that is independent of its size, shape, and distribution. We then show that finite-size effects eventually dominate radiation damping effects in describing the motion of a white dwarf around a more

  15. 2MASS J035523.37+113343.7: A YOUNG, DUSTY, NEARBY, ISOLATED BROWN DWARF RESEMBLING A GIANT EXOPLANET

    SciTech Connect

    Faherty, Jacqueline K.; Rice, Emily L.; Cruz, Kelle L.; Nunez, Alejandro; Mamajek, Eric E. E-mail: jfaherty@amnh.org

    2013-01-01

    We present parallax and proper motion measurements, near-infrared spectra, and Wide-field Infrared Survey Explorer photometry for the low surface gravity L5{gamma} dwarf 2MASS J035523.37+113343.7 (2M0355). We use these data to evaluate photometric, spectral, and kinematic signatures of youth as 2M0355 is the reddest isolated L dwarf yet classified. We confirm its low-gravity spectral morphology and find a strong resemblance to the sharp triangular shaped H-band spectrum of the {approx}10 Myr planetary-mass object 2M1207b. We find that 2M0355 is underluminous compared to a normal field L5 dwarf in the optical and Mauna Kea Observatory J, H, and K bands and transitions to being overluminous from 3 to 12 {mu}m, indicating that enhanced photospheric dust shifts flux to longer wavelengths for young, low-gravity objects, creating a red spectral energy distribution. Investigating the near-infrared color-magnitude diagram for brown dwarfs confirms that 2M0355 is redder and underluminous compared to the known brown dwarf population, similar to the peculiarities of directly imaged exoplanets 2M1207b and HR8799bcd. We calculate UVW space velocities and find that the motion of 2M0355 is consistent with young disk objects (<2-3 Gyr) and it shows a high likelihood of membership in the AB Doradus association.

  16. Near-infrared photometry and spectroscopy of the low Galactic latitude globular cluster 2MASS-GC 03

    NASA Astrophysics Data System (ADS)

    Carballo-Bello, Julio A.; Ramírez Alegría, S.; Borissova, J.; Smith, L. C.; Kurtev, R.; Lucas, P. W.; Moni Bidin, Ch.; Alonso-García, J.; Minniti, D.; Palma, T.; Dékány, I.; Medina, N.; Moyano, M.; Villanueva, V.; Kuhn, M. A.

    2016-10-01

    We present deep near-infrared photometry and spectroscopy of the globular cluster 2MASS-GC 03 projected in the Galactic disc using MMT and Magellan Infrared Spectrograph on the Clay Telescope (Las Campanas Observatory) and VISTA Variables in the Via Lactea Survey data. Most probable cluster member candidates were identified from near-infrared photometry. Out of 10 candidates that were followed-up spectroscopically, 5 have properties of cluster members, from which we calculate <[Fe/H]>= - 0.9 ± 0.2 and a radial velocity of = - 78 ± 12 km s-1. A distance of 10.8 kpc is estimated from three likely RR Lyrae members. Given that the cluster is currently at a distance of 4.2 kpc from the Galactic Centre, the cluster's long survival time of an estimated 11.3 ± 1.2 Gyr strengthens the case for its globular-cluster nature. The cluster has a hint of elongation in the direction of the Galactic Centre.

  17. 2MASS J035523.37+113343.7: A Young, Dusty, Nearby, Isolated Brown Dwarf Resembling a Giant Exoplanet

    NASA Astrophysics Data System (ADS)

    Faherty, Jacqueline K.; Rice, Emily L.; Cruz, Kelle L.; Mamajek, Eric E.; Núñez, Alejandro

    2013-01-01

    We present parallax and proper motion measurements, near-infrared spectra, and Wide-field Infrared Survey Explorer photometry for the low surface gravity L5γ dwarf 2MASS J035523.37+113343.7 (2M0355). We use these data to evaluate photometric, spectral, and kinematic signatures of youth as 2M0355 is the reddest isolated L dwarf yet classified. We confirm its low-gravity spectral morphology and find a strong resemblance to the sharp triangular shaped H-band spectrum of the ~10 Myr planetary-mass object 2M1207b. We find that 2M0355 is underluminous compared to a normal field L5 dwarf in the optical and Mauna Kea Observatory J, H, and K bands and transitions to being overluminous from 3 to 12 μm, indicating that enhanced photospheric dust shifts flux to longer wavelengths for young, low-gravity objects, creating a red spectral energy distribution. Investigating the near-infrared color-magnitude diagram for brown dwarfs confirms that 2M0355 is redder and underluminous compared to the known brown dwarf population, similar to the peculiarities of directly imaged exoplanets 2M1207b and HR8799bcd. We calculate UVW space velocities and find that the motion of 2M0355 is consistent with young disk objects (<2-3 Gyr) and it shows a high likelihood of membership in the AB Doradus association.

  18. The past photometric history of the FU Ori-type young eruptive star 2MASS J06593158-0405277 = V960 Mon

    NASA Astrophysics Data System (ADS)

    Jurdana-Šepić, Rajka; Munari, Ulisse

    2016-02-01

    The known FU Ori-type young eruptive stars are exceedingly rare (a dozen or so confirmed objects) and 2MASS J06593158-0405277, with its 2014 outburst, is likely the latest addition to the family. All members have displayed just one such eruption in their recorded history, an event lasting for decades. To test the FU Ori nature of 2MASS J06593158-0405277, we have reconstructed its photometric history by measuring its brightness on Harvard photographic plates spanning the time interval 1899-1989. No previous large amplitude eruption similar to that initiated in 2014 has been found, as in bona fide FU Ori-type objects. The median value of the brightness in quiescence of 2MASS J06593158-0405277 is B = 15.5, with the time interval 1935-1950 characterized by a large variability (˜ 1 mag amplitude) that contrasts with the remarkable photometric stability displayed at later epochs. The variability during 1935-1950 can either be ascribed to some T Tau like activity of 2MASS J06593158-0405277 itself or to the also young and fainter star 2MASS J06593168-0405224 that lies 5 arcsec to the North and forms an unresolved pair at the astrometric scale of Harvard photographic plates.

  19. Bioconvection in spatially extended domains

    NASA Astrophysics Data System (ADS)

    Karimi, A.; Paul, M. R.

    2013-05-01

    We numerically explore gyrotactic bioconvection in large spatially extended domains of finite depth using parameter values from available experiments with the unicellular alga Chlamydomonas nivalis. We numerically integrate the three-dimensional, time-dependent continuum model of Pedley [J. Fluid Mech.10.1017/S0022112088002393 195, 223 (1988)] using a high-order, parallel, spectral-element approach. We explore the long-time nonlinear patterns and dynamics found for layers with an aspect ratio of 10 over a range of Rayleigh numbers. Our results yield the pattern wavelength and pattern dynamics which we compare with available theory and experimental measurement. There is good agreement for the pattern wavelength at short times between numerics, experiment, and a linear stability analysis. At long times we find that the general sequence of patterns given by the nonlinear evolution of the governing equations correspond qualitatively to what has been described experimentally. However, at long times the patterns in numerics grow to larger wavelengths, in contrast to what is observed in experiment where the wavelength is found to decrease with time.

  20. Earth Observing-1 Extended Mission

    USGS Publications Warehouse

    ,

    2005-01-01

    Since November 2000, the National Aeronautics and Space Administration (NASA) Earth Observing-1 (EO-1) mission has demonstrated the capabilities of a dozen spacecraft sensor and communication innovations. Onboard the EO-1 spacecraft are two land remote sensing instruments. The Advanced Land Imager (ALI) acquires data in spectral bands and at resolutions similar to Landsat. The Hyperion instrument, which is the first civilian spaceborne hyperspectral imager, acquires data in 220 10-nanometer bands covering the visible, near, and shortwave-infrared bands. The initial one-year technology demonstration phase of the mission included a detailed comparison of ALI with the Landsat Enhanced Thematic Mapper Plus (ETM+) instrument. Specifications for the Operational Land Imager (OLI), the planned successor to ETM+, were formulated in part from performance characteristics of ALI. Recognizing the remarkable performance of the satellite's instruments and the exceptional value of the data, the U.S. Geological Survey (USGS) and NASA agreed in December 2001 to share responsibility for operating EO-1. The extended mission continues, on a cost-reimbursable basis, as long as customer sales fully recover flight and ground operations costs. As of May 2005, more than 17,800 scenes from each instrument have been acquired, indexed, archived, and made available to the public.

  1. Pair extended coupled cluster doubles

    SciTech Connect

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  2. Earth Observing-1 Extended Mission

    USGS Publications Warehouse

    ,

    2003-01-01

    From its beginning in November 2000, the NASA Earth Observing-1 (EO-1) mission demonstrated the feasibility and performance of a dozen innovative sensor, spacecraft, and operational technologies. The 1-year mission tested a variety of technologies, some of which may be included on the planned 2007 Landsat Data Continuity Mission. Onboard the spacecraft are two land remote sensing instruments: the Advanced Land Imager (ALI), which acquires data in spectral bands and at resolutions similar to Landsat, and Hyperion, which acquires data in 220 10-nanometer-wide bands covering the visible, near-, and shortwave-infrared bands. Recognizing the remarkable performance of the satellite's instruments and the exceptional value of the data, the U.S. Geological Survey (USGS) and NASA agreed in December 2001 to share responsibility for operating EO-1 on a cost-reimbursable basis as long as customer sales are sufficient to recover flight and ground operations costs. The EO-1 extended mission operates within constraints imposed by its technology-pioneering origins, but it also provides unique and valuable capabilities. The spacecraft can acquire a target scene three times in a 16-day period. The ALI instrument has additional spectral coverage and greater radiometric dynamic range compared with the sensors on Landsat 7. Hyperion is the first civilian spaceborne hyperspectral imager. As of January 2003, more than 5,000 scenes had been acquired, indexed, and archived.

  3. The Extended Mission Rover (EMR)

    NASA Astrophysics Data System (ADS)

    Shields, W.; Halecki, Anthony; Chung, Manh; Clarke, Ken; Frankle, Kevin; Kassemkhani, Fariba; Kuhlhoff, John; Lenzini, Josh; Lobdell, David; Morgan, Sam

    A key component in ensuring America's status as a leader in the global community is its active pursuit of space exploration. On the twentieth anniversary of Apollo 11, President George Bush challenged the nation to place a man on the moon permanently and to conduct human exploration of Mars in the 21st century. The students of the FAMU/FSU College of Engineering hope to make a significant contribution to this challenge, America's Space Exploration Initiative (SEI), with their participation in the NASA/USRA Advanced Design Program. The project selected by the 1991/1992 Aerospace Design group is the design of an Extended Mission Rover (EMR) for use on the lunar surface. This vehicle will serve as a mobile base to provide future astronauts with a 'shirt-sleeve' living and working environment. Some of the proposed missions are planetary surface exploration, construction and maintenance, hardware setup, and in situ resource experimentation. This vehicle will be put into use in the 2010-2030 time frame.

  4. Extended attention span training system

    NASA Technical Reports Server (NTRS)

    Pope, Alan T.; Bogart, Edward H.

    1991-01-01

    Attention Deficit Disorder (ADD) is a behavioral disorder characterized by the inability to sustain attention long enough to perform activities such as schoolwork or organized play. Treatments for this disorder include medication and brainwave biofeedback training. Brainwave biofeedback training systems feed back information to the trainee showing him how well he is producing the brainwave pattern that indicates attention. The Extended Attention Span Training (EAST) system takes the concept a step further by making a video game more difficult as the player's brainwaves indicate that attention is waning. The trainee can succeed at the game only by maintaining an adequate level of attention. The EAST system is a modification of a biocybernetic system that is currently being used to assess the extent to which automated flight management systems maintain pilot engagement. This biocybernetic system is a product of a program aimed at developing methods to evaluate automated flight deck designs for compatibility with human capabilities. The EAST technology can make a contribution in the fields of medical neuropsychology and neurology, where the emphasis is on cautious, conservative treatment of youngsters with attention disorders.

  5. The Extended Mission Rover (EMR)

    NASA Technical Reports Server (NTRS)

    Shields, W.; Halecki, Anthony; Chung, Manh; Clarke, Ken; Frankle, Kevin; Kassemkhani, Fariba; Kuhlhoff, John; Lenzini, Josh; Lobdell, David; Morgan, Sam

    1992-01-01

    A key component in ensuring America's status as a leader in the global community is its active pursuit of space exploration. On the twentieth anniversary of Apollo 11, President George Bush challenged the nation to place a man on the moon permanently and to conduct human exploration of Mars in the 21st century. The students of the FAMU/FSU College of Engineering hope to make a significant contribution to this challenge, America's Space Exploration Initiative (SEI), with their participation in the NASA/USRA Advanced Design Program. The project selected by the 1991/1992 Aerospace Design group is the design of an Extended Mission Rover (EMR) for use on the lunar surface. This vehicle will serve as a mobile base to provide future astronauts with a 'shirt-sleeve' living and working environment. Some of the proposed missions are planetary surface exploration, construction and maintenance, hardware setup, and in situ resource experimentation. This vehicle will be put into use in the 2010-2030 time frame.

  6. 38 CFR 21.74 - Extended evaluation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Extended evaluation. 21... Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... evaluation are listed in § 21.57(b) of this part. (Authority: 38 U.S.C. 3105(a), 3106(a)) (b) Duration....

  7. Bose-Einstein Condensation in Extended Microgravity

    NASA Astrophysics Data System (ADS)

    Scharringhausen, Marco; Quantus Team; Rasel, Ernst Maria

    2012-07-01

    The setup and the envisaged experiment timeline of the QUANTUS-III experiment onboard a sounding rocket to be started in the near future are presented. The major intention of QUANTUS-III is the stable generation of a number of Bose-Einstein condensates as a source for atom interferometry during several minutes of microgravity onboard the sounding rocket. Later missions aim at the realization of atom interferoemeters as precursor satellite missions. These condesates will be generated serially, allowing a large number of repeatable tests. Within such Bose-Einstein condensates, millions of atoms lose their identity and can be described by a single macroscopic wave function. During the expansion over several seconds, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter. Cold quantum gases and, in particular, Bose-Einstein condensates represent a new state of matter which is nowadays established in many laboratories. They offer unique insights into a broad range of fundamental physics as well as prospects for novel quantum sensors. Microgravity will substantially extend the science of quantum gases towards nowadays inaccessible regimes at lowest temperatures, to macroscopic dimensions, and to unequalled durations of unperturbed evolution of these distinguished quantum objects. Right now, the QUANTUS-III experiment is in the development phase, taking heritage from QUANTUS-I and QUANTUS-II. Major components of the engineering model are available. Boundary conditions of the rocket, requirements of the experiment and interface considerations are presented. This include laser stabilization, vacuum technology and magnetic shielding. The planned trajectory of the rocket will have an apogee of 200 - 300 km and a total microgravity time of 4 - 7 minutes, both depending on the total experiment mass.

  8. DYNAMICAL MASS OF THE M8+M8 BINARY 2MASS J22062280 - 2047058AB {sup ,} {sup ,} {sup ,}

    SciTech Connect

    Dupuy, Trent J.; Bowler, Brendan P.; Liu, Michael C.

    2009-11-20

    We present Keck laser guide star adaptive optics imaging of the M8+M8 binary 2MASS J2206 - 2047AB. Together with archival Hubble Space Telescope, Gemini-North, and Very Large Telescope data, our observations span 8.3 yr of the binary's 35{sup +6}{sub -5} yr orbital period, and we determine a total dynamical mass of 0.15{sup +0.05} {sub -0.03} M{sub sun}, with the uncertainty dominated by the parallax error. Using the measured total mass and individual luminosities, the Tucson and Lyon evolutionary models both give an age for the system of 0.4{sup +9.6}{sub -0.2} Gyr, which is consistent with its thin disk space motion derived from the Besancon Galactic structure model. Our mass measurement combined with the Tucson (Lyon) evolutionary models also yields precise effective temperatures, giving 2660{sup +90}{sub -100} K and 2640{sup +90}{sub -100} K (2550{sup +90}{sub -100} K and 2530{sup +90}{sub -100} K) for components A and B, respectively. These temperatures are in good agreement with estimates for other M8 dwarfs (from the infrared flux method and the M8 mass benchmark LHS 2397aA), but atmospheric model fitting of the integrated-light spectrum gives hotter temperatures of 2800 +- 100 K for both components. This modest discrepancy can be explained by systematic errors in the atmospheric models or by a slight underestimation of the distance (and thus, mass and age) of the system. We also find that the observed near-infrared colors and magnitudes do not agree with those predicted by the Lyon Dusty models, given the known mass of the system.

  9. VizieR Online Data Catalog: 3D reddening map for stars from 2MASS phot. (Gontcharov, 2010)

    NASA Astrophysics Data System (ADS)

    Gontcharov, G. A.

    2016-07-01

    A three-dimensional reddening map for stars within 1100pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the (J-Ks)-Ks diagram supplemented with Monte Carlo simulations has shown that one of the maxima of this distribution corresponds to F-type dwarfs and subgiants with a mean absolute magnitude MKs=2.5m. The shift of this maximum toward large (J-Ks) with increasing Ks reflects the reddening of these stars with increasing heliocentric distance. The distribution of the sample of stars over Ks, l, and b cells with a statistically significant number of stars in each cell corresponds to their distribution over three-dimensional spatial cells. As a result, the reddening E(J-Ks) has been determined with an accuracy of 0.03m for spatial cells with a side of 100pc. All of the known large absorbing clouds within 1100pc of the Sun have manifested themselves in the results obtained. The absorbing matter of the Gould Belt is shown to manifest itself at latitudes up to 40° and within 600pc of the Sun. The size and influence of the Gould Belt may have been underestimated thus far. The absorbing matter at latitudes up to 60° and within 1100pc of the Sun has been found to be distributed predominantly in the first and second quadrants in the southern hemisphere and in the third and fourth quadrants in the northern hemisphere. Also the data of the Rv (2012AstL...38...12G) and Av (2012AstL...38...87G) 3D maps are added. (1 data file).

  10. Risk characterization and the extended spaceflight environment

    NASA Astrophysics Data System (ADS)

    Irons, Richard D.; Eberhardt, Ralph; Schulz, Jon

    Recent trends toward prolonged space flights have highlighted concern over potential health hazards for crews occupying a confined habitat for an extended duration mission. Previous spaceflight and remote habitat experiences have identified a large number of compounds that pose potential hazards as space habitat contaminants. A project is underway to prioritize these compounds according to: 1) the degree of potential exposure, 2) known or potential health risks, 3) process- and mission-specific determination of sources of contamination, and 4) preliminary evaluation of mission performance degradations associated with compound containment or substitution. An effort is underway to establish a comprehensive database making use of all available national and international data in order to provide a basis from which to evaluate both the impact and the likelihood of long term or transient exposure to these agents. The database will define projected capabilities of Space Station Freedom from early assembly phase through man-tended and permanently-manned capability, previous knowledge of the lunar base environment, and the limited data available from the Viking mission for the Mars environment. This information will then form the basis for mitigation measures including: 1) future process modification or substitution, 2) special provisions for compound containment or use restrictions, 3) re-evaluation of current exposure standards, and 4) reprioritization of information needs (e.g., toxicology, effects on human performance, or re-evaluation of alternative-process mission requirements).

  11. Extending particle tracking capability with Delaunay triangulation.

    PubMed

    Chen, Kejia; Anthony, Stephen M; Granick, Steve

    2014-04-29

    Particle tracking, the analysis of individual moving elements in time series of microscopic images, enables burgeoning new applications, but there is need to better resolve conformation and dynamics. Here we describe the advantages of Delaunay triangulation to extend the capabilities of particle tracking in three areas: (1) discriminating irregularly shaped objects, which allows one to track items other than point features; (2) combining time and space to better connect missing frames in trajectories; and (3) identifying shape backbone. To demonstrate the method, specific examples are given, involving analyzing the time-dependent molecular conformations of actin filaments and λ-DNA. The main limitation of this method, shared by all other clustering techniques, is the difficulty to separate objects when they are very close. This can be mitigated by inspecting locally to remove edges that are longer than their neighbors and also edges that link two objects, using methods described here, so that the combination of Delaunay triangulation with edge removal can be robustly applied to processing large data sets. As common software packages, both commercial and open source, can construct Delaunay triangulation on command, the methods described in this paper are both computationally efficient and easy to implement.

  12. Fast interrupt platform for extended DOS

    NASA Technical Reports Server (NTRS)

    Duryea, T. W.

    1995-01-01

    Extended DOS offers the unique combination of a simple operating system which allows direct access to the interrupt tables, 32 bit protected mode access to 4096 MByte address space, and the use of industry standard C compilers. The drawback is that fast interrupt handling requires both 32 bit and 16 bit versions of each real-time process interrupt handler to avoid mode switches on the interrupts. A set of tools has been developed which automates the process of transforming the output of a standard 32 bit C compiler to 16 bit interrupt code which directly handles the real mode interrupts. The entire process compiles one set of source code via a make file, which boosts productivity by making the management of the compile-link cycle very simple. The software components are in the form of classes written mostly in C. A foreground process written as a conventional application which can use the standard C libraries can communicate with the background real-time classes via a message passing mechanism. The platform thus enables the integration of high performance real-time processing into a conventional application framework.

  13. Enhanced Graphics for Extended Scale Range

    NASA Technical Reports Server (NTRS)

    Hanson, Andrew J.; Chi-Wing Fu, Philip

    2012-01-01

    Enhanced Graphics for Extended Scale Range is a computer program for rendering fly-through views of scene models that include visible objects differing in size by large orders of magnitude. An example would be a scene showing a person in a park at night with the moon, stars, and galaxies in the background sky. Prior graphical computer programs exhibit arithmetic and other anomalies when rendering scenes containing objects that differ enormously in scale and distance from the viewer. The present program dynamically repartitions distance scales of objects in a scene during rendering to eliminate almost all such anomalies in a way compatible with implementation in other software and in hardware accelerators. By assigning depth ranges correspond ing to rendering precision requirements, either automatically or under program control, this program spaces out object scales to match the precision requirements of the rendering arithmetic. This action includes an intelligent partition of the depth buffer ranges to avoid known anomalies from this source. The program is written in C++, using OpenGL, GLUT, and GLUI standard libraries, and nVidia GEForce Vertex Shader extensions. The program has been shown to work on several computers running UNIX and Windows operating systems.

  14. Revealing topological superconductivity in extended quantum spin Hall Josephson junctions.

    PubMed

    Lee, Shu-Ping; Michaeli, Karen; Alicea, Jason; Yacoby, Amir

    2014-11-01

    Quantum spin Hall-superconductor hybrids are promising sources of topological superconductivity and Majorana modes, particularly given recent progress on HgTe and InAs/GaSb. We propose a new method of revealing topological superconductivity in extended quantum spin Hall Josephson junctions supporting "fractional Josephson currents." Specifically, we show that as one threads magnetic flux between the superconductors, the critical current traces an interference pattern featuring sharp fingerprints of topological superconductivity-even when noise spoils parity conservation.

  15. 30 CFR 75.802 - Protection of high-voltage circuits extending underground.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... which shall be grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors...

  16. 30 CFR 75.802 - Protection of high-voltage circuits extending underground.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... which shall be grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors...

  17. 30 CFR 75.802 - Protection of high-voltage circuits extending underground.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... which shall be grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors...

  18. 30 CFR 75.802 - Protection of high-voltage circuits extending underground.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... which shall be grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors...

  19. Stability profiles of drug products extended beyond labeled expiration dates.

    PubMed

    Lyon, Robbe C; Taylor, Jeb S; Porter, Donna A; Prasanna, Hullahalli R; Hussain, Ajaz S

    2006-07-01

    The American Medical Association has questioned whether expiration dating markedly underestimates the actual shelf life of drug products. Results from the shelf life extension program (SLEP) have been evaluated to provide extensive data to address this issue. The SLEP has been administered by the Food and Drug Administration for the United States Department of Defense (DOD) for 20 years. This program probably contains the most extensive source of pharmaceutical stability data extant. This report summarizes extended stability profiles for 122 different drug products (3,005 different lots). The drug products were categorized into five groups based on incidence of initial extension failures and termination failures (extended lot eventually failed upon re-testing). Based on testing and stability assessment, 88% of the lots were extended at least 1 year beyond their original expiration date for an average extension of 66 months, but the additional stability period was highly variable. The SLEP data supports the assertion that many drug products, if properly stored, can be extended past the expiration date. Due to the lot-to-lot variability, the stability and quality of extended drug products can only be assured by periodic testing and systematic evaluation of each lot. PMID:16721796

  20. COMBUSTION AREA SOURCES: DATA SOURCES

    EPA Science Inventory

    The report identifies, documents, and evaluates data sources for stationary area source emissions, including solid waste and agricultural burning. Area source emissions of particulate matter, sulfur dioxide, oxides of nitrogen, reactive volatile organic compounds, and carbon mon...

  1. Erratum: "Meeting the Cool Neighbors. X. Ultracool Dwarfs from the 2MASS All-Sky Data Release" (2008, AJ, 136, 1290)

    NASA Astrophysics Data System (ADS)

    Reid, I. Neill; Cruz, Kelle L.; Kirkpatrick, J. Davy; Allen, Peter R.; Mungall, F.; Liebert, James; Lowrance, Patrick; Sweet, Anne

    2008-11-01

    IOP Publishing sincerely regrets that an error was made in the acknowledgements section of this article. This has been amended in the online journal and the corrected text is reproduced below. The NStars research described in this paper was partially supported by a grant awarded as part of the NASA Space Interferometry Mission Science Program, administered by the Jet Propulsion Laboratory, Pasadena. Support for K.L.C. is provided by NASA through the Spitzer Space Telescope Fellowship Program, through a contract issued by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. P.R.A. acknowledges support from grant NAG5-11627 to Kevin Luhman from the NASA Long-Term Space Astrophysics program. This publication makes use of data products from the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and the National Science Foundation. We acknowledge use of the NASA/IPAC Infrared Source Archive (IRSA), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. We also acknowledge making extensive use of the SIMBAD database, maintained by Strasbourg Observatory, and of the ADS bibliographic service. This research has made extensive use of the M-, L-, and T-dwarf compendium housed at DwarfArchives.org and maintained by Chris Gelino, Davy Kirkpatrick, and Adam Burgasser. This program has also profited from extensive allocations of telescope time at both Kitt Peak Observatory and Cerro Tololo Inter-American Observatory (CTIO). We thank the National Optical Astronomy Observatory (NOAO) Telescope Allocation Committees for their support of this project and acknowledge the courteous and efficient assistance of the technical support staff: John Glaspey, Darryl Willmarth, Diane Harmer, Bill Gillespie, Hillary Mathis, and Hal Halbedel at KPNO, and

  2. Three-dimensional reddening map for stars from 2MASS photometry: The method and the first results

    NASA Astrophysics Data System (ADS)

    Gontcharov, G. A.

    2010-08-01

    The first results of the construction of a three-dimensional reddening map for stars within 1600 pc of the Sun are presented. Analysis of the distribution of 70 million stars from the 2MASS catalog with the most accurate photometry on the ( J-Ks)- Ks diagram supplemented with Monte Carlo simulations has shown that one of the maxima of this distribution corresponds to F-type dwarfs and subgiants with a mean absolute magnitude M Ks = 2{⊙/ m }5. The shift of this maximum toward large J-Ks with increasing Ks reflects the reddening of these stars with increasing heliocentric distance. The distribution of the sample of stars over Ks, l, and b cells with a statistically significant number of stars in each cell corresponds to their distribution over three-dimensional spatial cells. As a result, the reddening E( J-Ks) has been determined with an accuracy of 0{·/ m }03 for spatial cells with a side of 100 pc. All of the known large absorbing clouds within 1600 pc of the Sun have manifested themselves in the results obtained. The distances to the near and far edges of the clouds have been determined with a relative accuracy of 15%. The cases where unknown clouds are hidden behind known ones on the same line of sight have been found. The distance dependence of reddening is considered for various Galactic latitudes and longitudes. The absorbing matter of the Gould Belt is shown to manifest itself at latitudes up to 40° and within 600 pc of the Sun. The size and influence of the Gould Belt may have been underestimated thus far. The absorbing matter at latitudes up to 60° and within 1600 pc of the Sun has been found to be distributed predominantly in the first and second quadrants in the southern hemisphere and in the third and fourth quadrants in the northern hemisphere. The warping of the absorbing layer in the near Galaxy apparently manifests itself in this way. A nonrandom orientation of the clouds relative to the Sun is possible. The mass of the baryonic dark matter in

  3. A TARGETED SEARCH FOR PECULIARLY RED L AND T DWARFS IN SDSS, 2MASS, AND WISE: DISCOVERY OF A POSSIBLE L7 MEMBER OF THE TW HYDRAE ASSOCIATION

    SciTech Connect

    Kellogg, Kendra; Metchev, Stanimir; Geißler, Kerstin; Hicks, Shannon; Kirkpatrick, J. Davy; Kurtev, Radostin E-mail: smetchev@uwo.ca

    2015-12-15

    We present the first results from a targeted search for brown dwarfs with unusual red colors indicative of peculiar atmospheric characteristics. These include objects with low surface gravities or with unusual dust content or cloud properties. From a positional cross-match of SDSS, 2MASS, and WISE, we have identified 40 candidate peculiar early-L to early-T dwarfs that are either new objects or have not been identified as peculiar through prior spectroscopy. Using low-resolution spectra, we confirm that 10 of the candidates are either peculiar or potential L/T binaries. With a J − K{sub s} color of 2.62 ± 0.15 mag, one of the new objects—the L7 dwarf 2MASS J11193254–1137466—is among the reddest field dwarfs currently known. Its proper motion and photometric parallax indicate that it is a possible member of the TW Hydrae moving group. If confirmed, it would be the lowest-mass (5–6 M{sub Jup}) free-floating member. We also report a new T dwarf, 2MASS J22153705+2110554, that was previously overlooked in the SDSS footprint. These new discoveries demonstrate that despite the considerable scrutiny already devoted to the SDSS and 2MASS surveys, our exploration of these data sets is not yet complete.

  4. THE PPMXL CATALOG OF POSITIONS AND PROPER MOTIONS ON THE ICRS. COMBINING USNO-B1.0 AND THE TWO MICRON ALL SKY SURVEY (2MASS)

    SciTech Connect

    Roeser, S.; Demleitner, M.; Schilbach, E.

    2010-06-15

    USNO-B1.0 and the Two Micron All Sky Survey (2MASS) are the most widely used all-sky surveys. However, 2MASS has no proper motions at all, and USNO-B1.0 published only relative, not absolute (i.e., on the International Celestial Reference Frame (ICRS), proper motions. We performed a new determination of mean positions and proper motions on the ICRS system by combining USNO-B1.0 and 2MASS astrometry. This catalog is called PPMXL (VO access to the catalog is possible via http://vo.uni-hd.de/ppmxl), and it aims to be completed from the brightest stars down to about V {approx} 20 all sky. PPMXL contains about 900 million objects, some 410 million with 2MASS photometry, and is the largest collection of ICRS proper motions at present. As representative for the ICRS, we chose PPMX. The recently released UCAC3 could not be used because we found plate-dependent distortions in its proper motion system north of -20{sup 0} declination. UCAC3 served as an intermediate system for {delta} {<=} -20{sup 0}. The resulting typical individual mean errors of the proper motions range from 4 mas yr{sup -1} to more than 10 mas yr{sup -1} depending on observational history. The mean errors of positions at epoch 2000.0 are 80-120 mas, if 2MASS astrometry could be used, 150-300 mas else. We also give correction tables to convert USNO-B1.0 observations of, e.g., minor planets to the ICRS system.

  5. VizieR Online Data Catalog: WISE and 2MASS photometry of M giant stars (Li+, 2016)

    NASA Astrophysics Data System (ADS)

    Li, J.; Smith, M. C.; Zhong, J.; Hou, J.; Carlin, J. L.; Newberg, H. J.; Liu, C.; Chen, L.; Li, L.; Shao, Z.; Small, E.; Tian, H.

    2016-08-01

    We cross-matched our LAMOST spectroscopically confirmed sample of M giants, M dwarfs, and QSOs (see section 2) to the ALLWISE Source Catalog in the NASA/IPAC Infrared Science Archive, using a search radius of 3". We also applied some cuts detailed in section 3. (1 data file).

  6. Extend{trademark} customization -- Experiences and issues

    SciTech Connect

    Parker, R.Y.

    1997-12-09

    Extend{trademark} simulation software is a dynamic modeling package developed by Imagine That Incorporated. The Technology Modeling and Analysis group (TSA-7) at Los Alamos National Laboratory has used Extend extensively over the past few years as one of various tools employed to perform simulation modeling and analysis. Development efforts over much of this period have made Extend a more effective and efficient tool through block customization. TSA-7 has taken advantage of the built-in capability in Extend to allow users to create new or modify existing functional blocks from which simulation models are constructed. As a result, Extend is much more effective and efficient for the group`s applications. This paper summarizes block customization and simulation model development that markedly improved the utilization of the Extend software package. The material covered herein includes some background information on Extend, which is necessary for understanding the balance of the paper. Following the background, the paper addresses Extend block customization efforts, including advantages and disadvantages to customizing, and the impact customization has had on Extend modeling efforts in TSA-7. Brief descriptions of many customized blocks developed by the author are presented in the appendix.

  7. A survey of extended H2 emission from massive YSOs

    NASA Astrophysics Data System (ADS)

    Navarete, F.; Damineli, A.; Barbosa, C. L.; Blum, R. D.

    2015-07-01

    We present the results from a survey, designed to investigate the accretion process of massive young stellar objects (MYSOs) through near-infrared narrow-band imaging using the H2 ν=1-0 S(1) transition filter. A sample of 353 MYSO candidates was selected from the Red MSX Source survey using photometric criteria at longer wavelengths (infrared and submillimetre) and chosen with positions throughout the Galactic plane. Our survey was carried out at the Southern Astrophysical Research Telescope Telescope in Chile and Canada-France-Hawaii Telescope in Hawaii covering both hemispheres. The data reveal that extended H2 emission is a good tracer of outflow activity, which is a signpost of accretion process on young massive stars. Almost half of the sample exhibit extended H2 emission and 74 sources (21 per cent) have polar morphology, suggesting collimated outflows. The polar-like structures are more likely to appear on radio-quiet sources, indicating these structures occur during the pre-UCH II phase. We also found an important fraction of sources associated with fluorescent H2 diffuse emission that could be due to a more evolved phase. The images also indicate only ˜23 per cent (80) of the sample is associated with extant (young) stellar clusters. These results support the scenario in which massive stars are formed by accretion discs, since the merging of low-mass stars would not produce outflow structures.

  8. Extended scene wavefront sensor for space application

    NASA Astrophysics Data System (ADS)

    Bomer, Thierry; Ravel, Karen; Corlay, Gilles

    2015-10-01

    The spatial resolution of optical monitoring satellites increases continuously and it is more and more difficult to satisfy the stability constraints of the instrument. The compactness requirements induce high sensitivity to drift during storage and launching. The implementation of an active loop for the control of the performances for the telescope becomes essential, in the same way of astronomy telescopes on ground. The active loop requires disposing of informations in real time of optical distortions of the wavefront, due to mirror deformations. It is the role of the Shack-Hartmann wave front sensor studied by Sodern. It is located in the focal plane of the telescope, in edge of field of view, in order not to disturb acquisition by the main instrument. Its particular characteristic, compared to a traditional wavefront sensor is not only to work on point source as star image, but also on extended scenes, as those observed by the instrument. The exit pupil of the telescope is imaged on a micro lenses array by a relay optics. Each element of the micro lenses array generates a small image, drifted by the local wavefront slope. The processing by correlation between small images allows to measure local slope and to recover the initial wavefront deformation according to Zernike decomposition. Sodern has realized the sensor dimensioning and has studied out the comparison of various algorithms of images correlation making it possible to measure the local slopes of the wave front. Simulations, taking into account several types of detectors, enabled to compare the performances of these solutions and a choice of detector was carried out. This article describes the state of progress of the work done so far. It shows the result of the comparisons on the choice of the detector, the main features of the sensor definition and the performances obtained.

  9. A methodology for extending domain coverage in SemRep

    PubMed Central

    Rosemblat, Graciela; Shin, Dongwook; Kilicoglu, Halil; Sneiderman, Charles; Rindflesch, Thomas C.

    2013-01-01

    We describe a domain-independent methodology to extend SemRep coverage beyond the biomedical domain. SemRep, a natural language processing application originally designed for biomedical texts, uses the knowledge sources provided by the Unified Medical Language System (UMLS©). Ontological and terminological extensions to the system are needed in order to support other areas of knowledge. We extended SemRep's application by developing a semantic representation of a previously unsupported domain. This was achieved by adapting well-known ontology engineering phases and integrating them with the UMLS knowledge sources on which SemRep crucially depends. While the process to extend SemRep coverage has been successfully applied in earlier projects, this paper presents in detail the stepwise approach we followed and the mechanisms implemented. A case study in the field of medical informatics illustrates how the ontology engineering phases have been adapted for optimal integration with the UMLS. We provide qualitative and quantitative results, which indicate the validity and usefulness of our methodology. PMID:23973273

  10. Evaluation of Kentucky's Extended School Services Program.

    ERIC Educational Resources Information Center

    Meehan, Merrill L.; Cowley, Kimberly S.; Schumacher, Debbie; Hauser, Brenda

    The Extended School Services (ESS) program was established in 1990 as part of the Kentucky Education Reform Act. The program extends the school day, week, or year for students at risk of academic failure, providing them with additional instructional time to help them meet academic goals. An evaluation of ESS in 2001 utilized statewide surveys and…

  11. 38 CFR 21.74 - Extended evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) VOCATIONAL REHABILITATION AND EDUCATION Vocational Rehabilitation and Employment Under 38 U.S.C. Chapter 31 Duration of Rehabilitation Programs § 21.74 Extended evaluation. (a) General. An extended evaluation may be... concurrence of the Vocational Rehabilitation and Employment (VR&E) Officer before approving the extension of...

  12. ADD, LD and Extended Information Processing.

    ERIC Educational Resources Information Center

    Stolzenberg, J. B.; Cherkes-Julkowski, M.

    This study examines executive function and its relationship to attention dysfunction and working memory. It attempts to document the manifestations of executive function problems in school-related extended processing tasks, such as verbal problem-solving in math and reading of extended passages. Subjects (in grades 1-12) included 49 children with…

  13. Extended, Embodied Cognition and Second Language Acquisition

    ERIC Educational Resources Information Center

    Atkinson, Dwight

    2010-01-01

    A "cognitivist" approach to cognition has traditionally dominated second language acquisition (SLA) studies. In this article, I examine two alternative approaches--"extended cognition" and "embodied cognition"--for how they might help us conceptualize SLA. More specifically, I present: (i) summaries of extended and embodied cognition, followed by…

  14. Report on Extended Campus Library Services.

    ERIC Educational Resources Information Center

    Strickler, Sally Ann; And Others

    This report presents the results of a study of the Extended Campus Library Services program at Western Kentucky University (WKU), which was conducted by a committee appointed by the Director of University Libraries. A description of the program's goals and objectives is followed by a review of the extended campus programs in relation to similar…

  15. 42 CFR 488.720 - Extended surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Extended surveys. 488.720 Section 488.720 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.720 Extended surveys. (a) Purpose of survey. The purpose of an...

  16. 42 CFR 488.720 - Extended surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Extended surveys. 488.720 Section 488.720 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.720 Extended surveys. (a) Purpose of survey. The purpose of an...

  17. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  18. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  19. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  20. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  1. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  2. Extend School Day and Year for NCLB?

    ERIC Educational Resources Information Center

    Chmelynski, Carol

    2006-01-01

    This article highlights the extended-day program adopted by many schools. With so much material being crammed into the curriculum--and with so much time during the school day being devoted to the matter of test preparation--many schools have been looking at the possibility of extending the school day. Several schools are experimenting with longer…

  3. Teaching the Extended Modifier: A Transformational Approach.

    ERIC Educational Resources Information Center

    Mann, G. Thomas

    1985-01-01

    Offers a practical model for teaching the extended modifier that is economical and linguistically sound, based on the insights and methodology of transformational generative grammar. Five transformational rules are given for generating extended modifiers from relative clauses. Examples of transformations and two class exercises in German are also…

  4. Nonpoint Sources.

    ERIC Educational Resources Information Center

    Browne, F. X.

    1978-01-01

    Presented a literature review of nonpoint source effects on water quality and pollution covering: (1) water quality effects; (2) watershed studies; (3) nonpoint source models; and nonpoint source controls. A list of 122 references published in 1976 and 1977 is also presented. (HM)

  5. Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae: a threat from the kitchen.

    PubMed

    Tschudin-Sutter, Sarah; Frei, Reno; Stephan, Roger; Hächler, Herbert; Nogarth, Danica; Widmer, Andreas F

    2014-05-01

    Food is an established source of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Hand hygiene and cooking prevent transmission, but hands could be recontaminated by touching used cutting boards. ESBL-producing Escherichia coli were identified on 12% of cutting boards and 50% of gloves after poultry preparation, pointing to an important source for transmission. PMID:24709730

  6. Extended depth of focus for transmission x-ray microscope.

    PubMed

    Liu, Yijin; Wang, Junyue; Hong, Youli; Wang, Zhili; Zhang, Kai; Williams, Phillip A; Zhu, Peiping; Andrews, Joy C; Pianetta, Piero; Wu, Ziyu

    2012-09-01

    A fast discrete curvelet transform based focus-stacking algorithm for extending the depth of focus of a transmission x-ray microscope (TXM) is presented. By analyzing an image stack of a sample taken in a Z-scan, a fully in-focus image can be generated by the proposed scheme. With the extended depth of focus, it is possible to obtain 3D structural information over a large volume at nanometer resolution. The focus-stacking method has been demonstrated using a dataset taken with a laboratory x-ray source based TXM system. The possibility and limitations of generalizing this method to a synchrotron based TXM are also discussed. We expect the proposed method to be of important impact in 3D x-ray microscopy. PMID:22940998

  7. Stellar Astrophysics with Kepler from an Extended Mission Baseline

    NASA Astrophysics Data System (ADS)

    Still, Martin D.

    2012-05-01

    Kepler in an extended mission phase will continue to collect regular cadence time-series photometry across its one science field for some years beyond the nominal shutdown date of Nov 12, 2012. Primary science goals will continue to be the identification of Earth-sized exoplanets and the abundance of Earth-like analogs in the Galaxy. Continued spacecraft operations also opens new windows of opportunity for stellar astrophysics. An extended mission will continue to push out the boundaries of what is measurable in the areas of asteroseismology, active stars, gyrochronology and binary stars. With all Kepler data being delivered to the public archive without proprietary period, continued improvements in archived product and the support of open source software, the future of stellar astrophysics with Kepler promises to be rich. The data archive remains full of untapped potential, waiting for a new, larger wave of community participation.

  8. Nonpoint sources

    SciTech Connect

    Selzer, L.

    1994-12-31

    Nonpoint source pollution remains the most pervasive water quality issue faced today. Unlike pollution from point sources, nonpoint source pollution is diffuse both in terms of its origin and the manner in which it enters ground and surface waters. It results from a great variety of human activities that take place over a wide geographic area perhaps many hundreds or even thousands of acres. And unlike pollutants from point sources--which enter the environment at well-defined locations and in relatively even, continuous discharges--pollutants from nonpoint sources usually find their way into surface and ground waters in sudden surges associated with rainfall, thunderstorms, or snowmelt. The author discusses some of the most significant sources of nonpoint source pollution.

  9. High-precision 2MASS JHK{sub s} light curves and other data for RR Lyrae star SDSS J015450 + 001501: Strong constraints for nonlinear pulsation models

    SciTech Connect

    Szabó, Róbert; Ivezić, Željko; Kiss, László L.; Kolláth, Zoltán; Jones, Lynne; Becker, Andrew C.; Davenport, James R. A.; Sesar, Branimir; Cutri, Roc M.

    2014-01-01

    We present and discuss an extensive data set for the non-Blazhko ab-type RR Lyrae star SDSS J015450+001501, including optical Sloan Digital Sky Survey ugriz light curves and spectroscopic data, LINEAR and Catalina Sky Survey unfiltered optical light curves, and infrared Two Micron All Sky Survey (2MASS) JHK{sub s} and Wide-field Infrared Survey Explorer W1 and W2 light curves. Most notable is that light curves obtained by 2MASS include close to 9000 photometric measures collected over 3.3 yr and provide an exceedingly precise view of near-infrared variability. These data demonstrate that static atmosphere models are insufficient to explain multiband photometric light-curve behavior and present strong constraints for nonlinear pulsation models for RR Lyrae stars. It is a challenge to modelers to produce theoretical light curves that can explain data presented here, which we make publicly available.

  10. The symmetric extendibility of quantum states

    NASA Astrophysics Data System (ADS)

    Nowakowski, Marcin L.

    2016-09-01

    Studies on the symmetric extendibility of quantum states have become particularly important in the context of the analysis of one-way quantum measures of entanglement, and the distillability and security of quantum protocols. In this paper we analyze composite systems containing a symmetric extendible part, with particular attention devoted to the one-way security of such systems. Further, we introduce a new one-way entanglement monotone based on the best symmetric approximation of a quantum state and the extendible number of a quantum state. We underpin these results with geometric observations about the structures of multi-party settings which posses substantial symmetric extendible components in their subspaces. The impossibility of reducing the maximal symmetric extendibility by means of the one-way local operations and classical communication method is pointed out on multiple copies. Finally, we state a conjecture linking symmetric extendibility with the one-way distillability and security of all quantum states, analyzing the behavior of a private key in the neighborhood of symmetric extendible states.

  11. LOW-MASS TERTIARY COMPANIONS TO SPECTROSCOPIC BINARIES. I. COMMON PROPER MOTION SURVEY FOR WIDE COMPANIONS USING 2MASS

    SciTech Connect

    Allen, Peter R.; Burgasser, Adam J.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy

    2012-08-15

    We report the first results of a multi-epoch search for wide (separations greater than a few tens of AU), low-mass tertiary companions of a volume-limited sample of 118 known spectroscopic binaries within 30 pc of the Sun, using the Two Micron All Sky Survey Point Source Catalog and follow-up observations with the KPNO and CTIO 4 m telescopes. Note that this sample is not volume complete but volume limited, and, thus, there is incompleteness in our reported companion rates. We are sensitive to common proper motion companions with separations from roughly 200 AU to 10,000 AU ({approx}10'' {yields} {approx} 10'). From 77 sources followed-up to date, we recover 11 previously known tertiaries, 3 previously known candidate tertiaries, of which 2 are spectroscopically confirmed and 1 rejected, and 3 new candidates, of which 2 are confirmed and 1 rejected. This yields an estimated wide tertiary fraction of 19.5{sup +5.2}{sub -3.7}%. This observed fraction is consistent with predictions set out in star formation simulations where the fraction of wide, low-mass companions to spectroscopic binaries is >10%.

  12. Apparatus and methods for a human extender

    DOEpatents

    Jansen, John F.

    2001-01-01

    A human extender controller for interface between a human operator and a physical object through a physical plant. The human extender controller uses an inner-feedback loop to increase the equivalent damping of the operating system to stabilize the system when it contacts with the environment and reduces the impact of the environment variation by utilizing a high feedback gain, determined by a root locus sketch. Because the stability of the human extender controller of the present invention is greatly enhanced over that of the prior art, the present invention is able to achieve a force reflection ratio 500 to 1 and capable of handling loads above the two (2) ton range.

  13. Extended Hamiltonian approach to continuous tempering

    NASA Astrophysics Data System (ADS)

    Gobbo, Gianpaolo; Leimkuhler, Benedict J.

    2015-06-01

    We introduce an enhanced sampling simulation technique based on continuous tempering, i.e., on continuously varying the temperature of the system under investigation. Our approach is mathematically straightforward, being based on an extended Hamiltonian formulation in which an auxiliary degree of freedom, determining the effective temperature, is coupled to the physical system. The physical system and its temperature evolve continuously in time according to the equations of motion derived from the extended Hamiltonian. Due to the Hamiltonian structure, it is easy to show that a particular subset of the configurations of the extended system is distributed according to the canonical ensemble for the physical system at the correct physical temperature.

  14. Extended core for motor/generator

    DOEpatents

    Shoykhet, Boris A.

    2006-08-22

    An extended stator core in a motor/generator can be utilized to mitigate losses in end regions of the core and a frame of the motor/generator. To mitigate the losses, the stator core can be extended to a length substantially equivalent to or greater than a length of a magnetically active portion in the rotor. Alternatively, a conventional length stator core can be utilized with a shortened magnetically active portion to mitigate losses in the motor/generator. To mitigate the losses in the core caused by stator winding, the core can be extended to a length substantially equivalent or greater than a length of stator winding.

  15. Extended core for motor/generator

    DOEpatents

    Shoykhet, Boris A.

    2005-05-10

    An extended stator core in a motor/generator can be utilized to mitigate losses in end regions of the core and a frame of the motor/generator. To mitigate the losses, the stator core can be extended to a length substantially equivalent to or greater than a length of a magnetically active portion in the rotor. Alternatively, a conventional length stator core can be utilized with a shortened magnetically active portion to mitigate losses in the motor/generator. To mitigate the losses in the core caused by stator winding, the core can be extended to a length substantially equivalent or greater than a length of stator winding.

  16. Extended Radio Emission in MOJAVE Blazars: Challenges to Unification

    NASA Astrophysics Data System (ADS)

    Kharb, P.; Lister, M. L.; Cooper, N. J.

    2010-02-01

    We present the results of a study on the kiloparsec-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud active galactic nuclei. New 1.4 GHz Very Large Array (VLA) radio images of six quasars and previously unpublished images of 21 blazars are presented, along with an analysis of the high-resolution (VLA A-array) 1.4 GHz emission for the entire sample. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. We expect more sensitive radio observations, however, to detect faint emission in these sources, as we have detected in the erstwhile "core-only" source, 1548+056. The kiloparsec-scale radio morphology varies widely across the sample. Many BL Lac objects exhibit extended radio power and kiloparsec-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lac objects to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and parsec-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low-frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and apparent parsec-scale jet speeds vary smoothly between different blazar subclasses, suggesting that, at least in terms of radio jet properties, the distinction between quasars and BL Lac objects, at an emission-line equivalent width of 5 Å, is essentially an arbitrary one. While the two blazar subclasses display a smooth continuation in properties, they often reveal differences in the correlation test results when considered separately. This can be understood if, unlike quasars, BL Lac objects do not constitute a homogeneous population, but rather include both FRI and FRII radio galaxies for

  17. GALACTIC CEPHEIDS WITH SPITZER. II. SEARCH FOR EXTENDED INFRARED EMISSION

    SciTech Connect

    Barmby, P.; Marengo, M.; Evans, N. R.; Huelsman, D.; Fazio, G. G.; Bono, G.; Su, K. Y. L.; Welch, D. L.

    2011-02-15

    A deep and detailed examination of 29 classical Cepheids with the Spitzer Space Telescope has revealed three stars with strong nearby extended emission detected in multiple bands which appears to be physically associated with the stars. RS Pup was already known to possess extended infrared emission, while the extended emission around the other two stars (S Mus and {delta} Cep) is newly discovered in our observations. Four other stars (GH Lup, l Car, T Mon, and X Cyg) show tentative evidence for extended infrared emission. An unusual elongated extended object next to SZ Tau appears to be a background or foreground object in a chance alignment with the Cepheid. The inferred mass-loss rate upper limits for S Mus and {delta} Cep are in the range from 10{sup -9} to 10{sup -8} M{sub sun} yr{sup -1}, with the upper limit for RS Pup as high as 10{sup -6} M{sub sun} yr{sup -1}. Mass loss during post-main-sequence evolution has been proposed as a resolution to the discrepancy between pulsational and dynamical masses of Cepheid variable stars: dust in the lost material would make itself known by the presence of an infrared bright nebula or unresolved infrared excess. The observed frequency of infrared circumstellar emission (<24%) and the mass-loss rate we estimate for our sources show that dusty mass loss can only account for part of the Cepheid mass-loss discrepancy. Nevertheless, our direct evidence that mass loss is active during the Cepheid phase is an important confirmation that these processes need to be included in evolutionary and pulsation models of these stars and should be taken into account in the calibration of the Cepheid distance scale.

  18. Large area plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor); Patterson, Michael (Inventor)

    2008-01-01

    An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.

  19. Extending applicability of terahertz spectroscopy for biosensing

    NASA Astrophysics Data System (ADS)

    Parthasarathy, Ramakrishnan

    Terahertz (THz) vibrational resonance spectroscopy has recently emerged as a promising technique for fingerprinting biological molecules. Absorption spectra in this frequency range (0.1-10 THz) reflect molecular internal vibrations involving the weakest hydrogen bonds and/or non-bonded interactions, which are species specific. Of prime importance is improving detection sensitivity of molecules with low absorption characteristics in the THz gap. Also of importance is the characterization of biological molecules in the THz gap (10-25 cm-1) by physical parameters (refractive index and absorption coefficient) rather than sample dependent parameters (transmission, reflection) and extending spectroscopy to the low THz range where remote sensing is most viable. To address the sensitivity issue, it is shown that periodic arrays of rectangular slots with subwavelength width provide for local electromagnetic field enhancements due to edge effects in the low frequency range of interest, 10-25 cm-1 (300-750 GHz). Periodic structures of Au, doped Si and InSb were studied. InSb is confirmed to offer the highest results with the local power enhancements on the order of 1100 at frequency 14 cm -1. InSb and Si have large skin depths in the frequency range of interest and so the analysis of their structures was done through the Fourier expansion method of field diffracted from gratings. Au however has small skin depths at these frequencies compared to the thickness. Surface impedance boundary conditions were employed to model the Au structure, for which the Fourier expansion method was unsuitable owing to the huge magnitude of Au permittivity. The applications possibly include development of novel bio-sensors, with the strongly enhanced local electromagnetic fields leading to increased detection sensitivity, and monitoring biophysical processes such as DNA denaturation. Transmission and reflection data from parallel, independent experiments are utilized in the Interference

  20. Generalized Laplace Transforms and Extended Heaviside Calculus

    ERIC Educational Resources Information Center

    Deakin, Michael A. B.

    2008-01-01

    An extended Heaviside calculus proposed by Peraire in a recent paper is similar to a generalization of the Laplace transform proposed by the present author. This similarity will be illustrated by analysis of an example supplied by Peraire.

  1. Extended Adjuvant Therapy for Breast Cancer

    Cancer.gov

    An NCI Cancer Currents blog on findings from a recent clinical trial which showed that extending adjuvant therapy with an aromatase inhibitor can have important benefits for some women with early-stage cancer.

  2. Group theoretical construction of extended baryon operators in lattice QCD

    SciTech Connect

    Subhasish Basak; Robert Edwards; George Fleming; Urs Heller; Colin Morningstar; David Richards; Ikuro Sato; Stephen Wallace

    2005-06-01

    The design and implementation of large sets of spatially-extended, gauge-invariant operators for use in determining the spectrum of baryons in lattice QCD computations are described. Group theoretical projections onto the irreducible representations of the symmetry group of a cubic spatial lattice are used in all isospin channels. The operators are constructed to maximize overlaps with the low-lying states of interest, while minimizing the number of sources needed in computing the required quark propagators. Issues related to the identification of the spin quantum numbers of the states in the continuum limit are addressed.

  3. Ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  4. Extended service 5w-40 motor oil

    SciTech Connect

    Schiemen, R.D.

    1983-09-06

    An extended drain 5W-40 motor oil composition for internal combustion engines comprises a base oil component of one or more solvent extracted mineral oils and a high refractory mineral oil, a V.I. improver, and preferably other suitable lube oil additives. The finished oil formulation has characteristics of minimal viscosity at low temperatures, low volatility at higher temperatures, and stable viscosity over extended use.

  5. eXtended MetaData Registry

    2006-10-25

    The purpose of the eXtended MetaData Registry (XMDR) prototype is to demonstrate the feasibility and utility of constructing an extended metadata registry, i.e., one which encompasses richer classification support, facilities for including terminologies, and better support for formal specification of semantics. The prototype registry will also serve as a reference implementation for the revised versions of ISO 11179, Parts 2 and 3 to help guide production implementations.

  6. An extended duration hybrid powered hexcopter

    NASA Astrophysics Data System (ADS)

    Winningham, Jason D.

    This work attempts to extend the flight time of a UAS to allow for longer ranges, extended time on station, and larger payloads by adding lift capacity for an auxiliary power unit that generates electrical power using an internal combustion engine. The UAS is instrumented to examine power consumption during flights with various payload masses. Safety aspects of the larger UAS are examined, including a safety analysis of the flight control software.

  7. Supradiaphragmatic bronchogenic cyst extending into the retroperitoneum.

    PubMed

    Jo, Won-Min; Shin, Jae Seung; Lee, In Sung

    2006-01-01

    We experienced a case of bronchogenic cyst located on the left lower pleural space extending into the retroperitoneum in a 33-year-old man with left chest pain. Preoperative imaging studies and operative findings showed a broad-based cystic mass on the left lower posterior pleura and diaphragmatic pleura extending into the retroperitoneal region across the diaphragm. Histologic studies proved this mass to be a bronchogenic cyst.

  8. Extended-release methylphenidate (Ritalin LA).

    PubMed

    Lyseng-Williamson, Katherine A; Keating, Gillian M

    2002-01-01

    An extended-release formulation of methylphenidate (Ritalin LA), a CNS stimulant that inhibits dopamine and noradrenaline (norepinephrine) reuptake into presynaptic neurons, has been developed for use in patients with attention deficit/hyperactivity disorder (ADHD). In children with ADHD and healthy male adults, extended-release methylphenidate 20mg was rapidly absorbed and demonstrated two distinct peak plasma concentrations approximately 4 hours apart. The absorption pharmacokinetics of extended-release methylphenidate 20mg, which closely mimics those of immediate-release methylphenidate 10mg given in two doses 4 hours apart, permits once-daily administration. In a 2-week randomised, double-blind, placebo-controlled trial in 134 evaluable children aged 6 to 12 years with ADHD, symptoms improved to a significantly greater extent with extended-release methylphenidate 10 to 40mg once daily than with placebo. Extended-release methylphenidate improved both inattention and hyperactivity symptoms and was effective in children with combined- (inattentive and hyperactive/impulsive) type or predominantly inattentive-type ADHD. In clinical trials, the safety and tolerability profiles of extended-release methylphenidate were consistent with that of the immediate-release formulation.

  9. CO2 mass estimation visible in time-lapse 3D seismic data from a saline aquifer and uncertainties

    NASA Astrophysics Data System (ADS)

    Ivanova, A.; Lueth, S.; Bergmann, P.; Ivandic, M.

    2014-12-01

    At Ketzin (Germany) the first European onshore pilot scale project for geological storage of CO2 was initiated in 2004. This project is multidisciplinary and includes 3D time-lapse seismic monitoring. A 3D pre-injection seismic survey was acquired in 2005. Then CO2 injection into a sandstone saline aquifer started at a depth of 650 m in 2008. A 1st 3D seismic repeat survey was acquired in 2009 after 22 kilotons had been injected. The imaged CO2 signature was concentrated around the injection well (200-300 m). A 2nd 3D seismic repeat survey was acquired in 2012 after 61 kilotons had been injected. The imaged CO2 signature further extended (100-200 m). The injection was terminated in 2013. Totally 67 kilotons of CO2 were injected. Time-lapse seismic processing, petrophysical data and geophysical logging on CO2 saturation have allowed for an estimate of the amount of CO2 visible in the seismic data. This estimate is dependent upon a choice of a number of parameters and contains a number of uncertainties. The main uncertainties are following. The constant reservoir porosity and CO2 density used for the estimation are probably an over-simplification since the reservoir is quite heterogeneous. May be velocity dispersion is present in the Ketzin reservoir rocks, but we do not consider it to be large enough that it could affect the mass of CO2 in our estimation. There are only a small number of direct petrophysical observations, providing a weak statistical basis for the determination of seismic velocities based on CO2 saturation and we have assumed that the petrophysical experiments were carried out on samples that are representative for the average properties of the whole reservoir. Finally, the most of the time delay values in the both 3D seismic repeat surveys within the amplitude anomaly are near the noise level of 1-2 ms, however a change of 1 ms in the time delay affects significantly the mass estimate, thus the choice of the time-delay cutoff is crucial. In spite

  10. Reconciling the MOLA, TES, and Neutron Observations of the North Polar CO2 Mass Budget on Mars

    NASA Technical Reports Server (NTRS)

    Haberle, R. M.; Mattingly, B.; Titus, T. N.

    2003-01-01

    There are now three independent observations of the CO2 polar cap mass budget of Mars' north polar cap. The first is based elevation changes detected by the Mars Orbiter Laser Altimeter (MOLA) on the Mars Global Surveyor (MGS). The second is based on MGS Thermal Emission Spectrometer (TES) broadband observations of the solar and infrared radiation fields at the top of the atmosphere. The third is based on neutron counts measured by the neutron spectrometer (NS) on Odyssey. The TES data are based on an energy balance. The net radiative loss (gain) in a column is balanced by latent heating due condensation (sublimation) of CO2. In calculating the mass budget, the other main energy sources, atmospheric heat transport and subsurface conduction, were neglected. At the pole, atmospheric heat transport is indeed a small term. However, subsurface heat conduction can be significant because at the North Pole water ice, which has a high thermal conductivity compared to bare soil, is a dominant component of the subsurface. Thus, heat conducted down into the ice during summer will slowly bleed back out during fall and winter reducing the amount of CO2 that condenses on the pole. We have taken a first cut at quantifying this effect by fitting a curve to Paige's estimates of the conducted energy flux in his analysis of Viking IRTM data.

  11. Comparison of methods for the analysis of therapeutic immunoglobulin G Fc-glycosylation profiles—Part 2: Mass spectrometric methods

    PubMed Central

    Reusch, Dietmar; Haberger, Markus; Falck, David; Peter, Britta; Maier, Bernd; Gassner, Jana; Hook, Michaela; Wagner, Katharina; Bonnington, Lea; Bulau, Patrick; Wuhrer, Manfred

    2015-01-01

    To monitor the Fc glycosylation of therapeutic immunoglobulin G in bioprocess development, product characterization and release analytics, reliable techniques for glycosylation analysis are needed. Several analytical methods are suitable for this application. We recently presented results comparing detection methods for glycan analysis that are separation-based, but did not include mass spectrometry (MS). In the study reported here, we comprehensively compared MS-based methods for Fc glycosylation profiling of an IgG biopharmaceutical. A therapeutic antibody reference material was analyzed 6-fold on 2 different days, and the methods investigated were compared with respect to precision, accuracy, throughput and analysis time. Emphasis was put on the detection and quantitation of sialic acid-containing glycans. Eleven MS methods were compared to hydrophilic interaction liquid chromatography of 2-aminobenzamide labeled glycans with fluorescence detection, which served as a reference method and was also used in the first part of the study. The methods compared include electrospray MS of the heavy chain and Fc part after limited digestion, liquid chromatography MS of a tryptic digest, porous graphitized carbon chromatography MS of released glycans, electrospray MS of glycopeptides, as well as matrix assisted laser desorption ionization MS of glycans and glycopeptides. Most methods showed excellent precision and accuracy. Some differences were observed with regard to the detection and quantitation of low abundant glycan species like the sialylated glycans and the amount of artefacts due to in-source decay. PMID:25996192

  12. Structure of the extended emission in the infrared celestial background

    SciTech Connect

    Price, S.D.

    1988-01-01

    The extended infrared celestial emission is due to three main sources: zodiacal dust, large discrete objects in the galaxy, and interstellar dust. As viewed from earth orbit, the thermal reradiation of sunlight absorbed by dust in the solar system produces a pervasive IR background that peaks roughly along the ecliptic plane, where the density of dust is highest. Much-smaller-scale structure was also observed in both the visual and infrared. Between 7 and 30 micrometers, H II regions are the brightest discrete objects in the galaxy. An additional emission mechanism is needed, however, to account for the shorter-wavelength observations. The galactic sources combine along the line of sight to produce an intense band of emission, centered on the galactic plane. Structure in all of these backgrounds creates a clutter problem for an orbiting IR telescope.

  13. The Ultraviolet Sky: final catalogs of unique UV sources from GALEX, and characterization of the UV-emitting sources across the sky, and of the Milky Way extinction

    NASA Astrophysics Data System (ADS)

    Bianchi, Luciana; Conti, A.; Shiao, B.; Keller, G. R.; Thilker, D. A.

    2014-01-01

    The legacy of the Galaxy Evolution Explorer (GALEX), which imaged the sky at Ultraviolet (UV) wavelengths for about 9 years, is its unprecedented database with more than 200 million source measurements in far-UV (FUV) and near-UV (NUV), as well as wide-field imaging of extended objects. GALEX's data, the first substantial sky surveys at UV wavelengths, offer an unprecedented view of the sky and a unique opportunity for an unbiased characterization of several classes of astrophysical objects, such as hot stars, QSOs at red-shift about 1, UV-peculiar QSOs, star-forming galaxies, among others. Bianchi et al. (2013, J. Adv. Space Res. (2013), DOI: http://dx.doi.org/10.1016/j.asr.2013.07.045) have constructed final catalogs of UV sources, with homogeneous quality, eliminating duplicate measurements of the same source ('unique' source catalogs), and excluding rim artifacts and bad photometry. The catalogs are constructed improving on the recipe of Bianchi et al. 2011 (MNRAS, 411, 2770, which presented the earlier version of these catalogs) and include all data for the major surveys, AIS and MIS. Considering the fields where both FUV and NUV detectors were exposed, the catalogs contain about 71 and 16.6 million unique sources respectively. We show several maps illustrating the content of UV sources across the sky, globally, and separately for bright/faint, hot, stellar/extragalactic objects. We matched the UV-source catalogs with optical-IR data from the SDSS, GSC2, 2MASS surveys. We are also in the process of matching the catalogs with preliminary PanSTARRS1 (PS1) 3pi survey photometry which already provides twice the sky coverage of SDSS, at slightly fainter magnitude limits. The sources' SED from FUV to optical wavelengths enables classification, derivation of the object physical parameters, and ultimately also a map of the Milky Way extinction. The catalogs will be available on MAST, Vizier (where the previous version already is), and in reduced form (for agile

  14. The Extended Ionized Halos and Bridge of the Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Krishnarao, Dhanesh; Smart, Brianna; Haffner, L. Matthew; Barger, Kathleen; Madsen, Gregory J.; Hill, Alex S.; Gaensler, Bryan M.

    2016-01-01

    The Wisconsin H-Alpha Mapper (WHAM) has revealed ubiquitous ionized emission throughout the gas complexes formed by the dynamic history of the Magellanic Clouds. We present an overview of the immediate environment around the galaxies themselves, including ionized halos of the Small and Large Magellanic Clouds (SMC & LMC) as well as the bridge of material between them. Using WHAM, Barger et al. (2013) found Hα emission extending throughout and beyond H I in the Bridge. We add these new maps of the SMC and LMC to provide the first complete view of the diffuse ionized gas near the interacting system. At R ~ 30,000, WHAM can cleanly separate diffuse emission at Magellanic velocities from the Milky Way and terrestrial sources to the limit of atmospheric line confusion (~ 10s of mR). We find that ionized gas extends at least 5° beyond the traditional boundary of the SMC when compared to recent deep-imaging surveys (e.g., MCELS; Smith et al. 2005). The diffuse ionized emission extent is similar to the neutral gas extent as traced by 21 cm emission. We compare the kinematic signatures between the neutral and ionized components throughout the region. Comprehensive multi-wavelength surveys are also underway to examine how physical parameters and ionization processes vary in these extended systems. WHAM research and operations are supported through NSF Award AST-1108911.

  15. Solute drag on perfect and extended dislocations

    NASA Astrophysics Data System (ADS)

    Sills, R. B.; Cai, W.

    2016-04-01

    The drag force exerted on a moving dislocation by a field of mobile solutes is studied in the steady state. The drag force is numerically calculated as a function of the dislocation velocity for both perfect and extended dislocations. The sensitivity of the non-dimensionalized force-velocity curve to the various controlling parameters is assessed, and an approximate analytical force-velocity expression is given. A non-dimensional parameter S characterizing the strength of the solute-dislocation interaction, the background solute fraction ?, and the dislocation character angle ?, are found to have the strongest influence on the force-velocity curve. Within the model considered here, a perfect screw dislocation experiences no solute drag, but an extended screw dislocation experiences a non-zero drag force that is about 10 to 30% of the drag on an extended edge dislocation. The solutes can change the spacing between the Shockley partials in both stationary and moving extended dislocations, even when the stacking fault energy remains unaltered. Under certain conditions, the solutes destabilize an extended dislocation by either collapsing it into a perfect dislocation or causing the partials to separate unboundedly. It is proposed that the latter instability may lead to the formation of large faulted areas and deformation twins in low stacking fault energy materials containing solutes, consistent with experimental observations of copper and stainless steel containing hydrogen.

  16. EXTENDED HOT HALOS AROUND ISOLATED GALAXIES OBSERVED IN THE ROSAT ALL-SKY SURVEY

    SciTech Connect

    Anderson, Michael E.; Bregman, Joel N.; Dai, Xinyu E-mail: jbregman@umich.edu

    2013-01-10

    We place general constraints on the luminosity and mass of hot X-ray-emitting gas residing in extended 'hot halos' around nearby massive galaxies. We examine stacked images of 2165 galaxies from the 2MASS Isolated Galaxy Catalog as well as subsets of this sample based on galaxy morphology and K-band luminosity. We detect X-ray emission at high confidence (ranging up to nearly 10{sigma}) for each subsample of galaxies. The average L{sub X} within 50 kpc is 1.0 {+-} 0.1 (statistical) {+-}0.2 (systematic) Multiplication-Sign 10{sup 40} erg s{sup -1}, although the early-type galaxies are more than twice as luminous as the late-type galaxies. Using a spatial analysis, we also find evidence for extended emission around five out of seven subsamples (the full sample, the luminous galaxies, early-type galaxies, luminous late-type galaxies, and luminous early-type galaxies) at 92.7%, 99.3%, 89.3%, 98.7%, and 92.1% confidence, respectively. Several additional lines of evidence also support this conclusion and suggest that about 1/2 of the total emission is extended, and about 1/3 of the extended emission comes from hot gas. For the sample of luminous galaxies, which has the strongest evidence for extended emission, the average hot gas mass is 4 Multiplication-Sign 10{sup 9} M {sub Sun} within 50 kpc and the implied accretion rate is 0.4 M {sub Sun} yr{sup -1}.

  17. Lens-focused transducer modeling using an extended KLM model.

    PubMed

    Maréchal, Pierre; Levassort, Franck; Tran-Huu-Hue, Louis-Pascal; Lethiecq, Marc

    2007-05-01

    The goal of this work was to develop an extended ultrasound transducer model that would optimize the trade-off between accuracy of the calculation and computational time. The derivations are presented for a generalized transducer model, that is center frequency, pulse duration and physical dimensions are all normalized. The paper presents a computationally efficient model for lens-focused, circular (axisymmetric) single element piezoelectric ultrasound transducer. Specifically, the goal of the model is to determine the lens effect on the electro-acoustic response, both on focusing and on matching acoustic properties. The effective focal distance depends on the lens geometry and refraction index, but also on the near field limit, i.e. wavelength and source radius, and on the spectrum bandwidth of the ultrasound source. The broadband (80%) source generated by the transducer was therefore considered in this work. A new model based on a longitudinal-wave assumption is presented and the error introduced by this assumption is discussed in terms of its maximum value (16%) and mean value (5.9%). The simplified model was based on an extension of the classical KLM model for transducer structures and on the related assumptions. The validity of the implemented extended KLM model was evaluated by comparison with finite element modeling, itself previously validated analytically for the one-dimensional planar geometry considered. The pressure field was then propagated using the adequate formulation of the Rayleigh integral for both the extended KLM and finite element results. The simplified approach based on the KLM model delivered the focused response with good accuracy, and hundred-fold lower calculation time in comparison with a mode comprehensive FEM method. The trade-off between precision and time thus becomes compatible with an iterative procedure, used here for the optimization of the acoustic impedance of the lens for the chosen configuration. An experimental comparison

  18. Light Source

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

  19. The flip-flop nozzle extended to supersonic flows

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Hailye, Michael; Rice, Edward J.

    1992-01-01

    An experiment studying a fluidically oscillated rectangular jet flow was conducted. The Mach number was varied over a range from low subsonic to supersonic. Unsteady velocity and pressure measurements were made using hot wires and piezoresistive pressure transducers. In addition smoke flow visualization using high speed photography was used to document the oscillation of the jet. For the subsonic flip-flop jet it was found that the apparent time-mean widening of the jet was not accompanied by an increase in mass flux. It was found that it is possible to extend the operation of these devices to supersonic flows. Most of the measurements were made for a fixed nozzle geometry for which the oscillations ceased at a fully expanded Mach number of 1.58. By varying the nozzle geometry this limitation was overcome and operation was extended to Mach 1.8. The streamwise velocity perturbation levels produced by this device were much higher than the perturbation levels that could be produced using conventional excitation sources such as acoustic drivers. In view of this ability to produce high amplitudes, the potential for using small scale fluidically oscillated jet as an unsteady excitation source for the control of shear flows in full scale practical applications seems promising.

  20. The flip flop nozzle extended to supersonic flows

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Hailye, Michael; Rice, Edward J.

    1992-01-01

    An experiment studying a fluidically oscillated rectangular jet flow was conducted. The Mach number was varied over a range from low subsonic to supersonic. Unsteady velocity and pressure measurements were made using hot wires and piezoresistive pressure transducers. In addition smoke flow visualization using high speed photography was used to document the oscillation of the jet. For the subsonic flip-flop jet it was found that the apparent time-mean widening of the jet was not accompanied by an increase in mass flux. It was found that it is possible to extend the operation of these devices to supersonic flows. Most of the measurements were made for a fixed nozzle geometry for which the oscillations ceased at a fully expanded Mach number of 1.58. By varying the nozzle geometry this limitation was overcome and operation was extended to Mach 1.8. The streamwise velocity perturbation levels produced by this device were much higher than the perturbation levels that could be produced using conventional excitation sources such as acoustic drivers. In view of this ability to produce high amplitudes, the potential for using small scale fluidically oscillated jet as an unsteady excitation source for the control of shear flows in full scale practical applications seems promising.

  1. [Ischemic cholangiopathy induced by extended burns].

    PubMed

    Cohen, Laurence; Angot, Emilie; Goria, Odile; Koning, Edith; François, Arnaud; Sabourin, Jean-Christophe

    2013-04-01

    Ischemic cholangiopathy is a recently described entity occurring mainly after hepatic grafts. Very few cases after intensive care unit (ICU) for extended burn injury were reported. We report the case of a 73-year-old woman consulting in an hepatology unit, for a jaundice appearing during a hospitalisation in an intensive care unit and increasing from her leaving from ICU, where she was treated for an extended burn injury. She had no pre-existing biological features of biliary disease. Biological tests were normal. Magnetic resonance imaging acquisitions of biliary tracts pointed out severe stenosing lesions of diffuse cholangiopathy concerning intrahepatic biliary tract, mainly peri-hilar. Biopsie from the liver confirmed the diagnosis, showing a biliary cirrhosis with bile infarcts. This case is the fourth case of ischemic cholangiopathy after extended burn injury, concerning a patient without a prior history of hepatic or biliary illness and appearing after hospitalisation in intensive care unit.

  2. Remarkable connections between extended magnetohydrodynamics models

    SciTech Connect

    Lingam, M. Morrison, P. J. Miloshevich, G.

    2015-07-15

    Through the use of suitable variable transformations, the commonality of all extended magnetohydrodynamics (MHD) models is established. Remarkable correspondences between the Poisson brackets of inertialess Hall MHD and inertial MHD (which has electron inertia, but not the Hall drift) and extended MHD (which has both effects) are established. The helicities (two in all) for each of these models are obtained through these correspondences. The commonality of all the extended MHD models is traced to the existence of two Lie-dragged 2-forms, which are closely associated with the canonical momenta of the two underlying species. The Lie-dragging of these 2-forms by suitable velocities also leads to the correct equations of motion. The Hall MHD Poisson bracket is analyzed in detail, the Jacobi identity is verified through a detailed proof, and this proof ensures the Jacobi identity for the Poisson brackets of all the models.

  3. Extended inflation from higher dimensional theories

    SciTech Connect

    Holman, R.; Kolb, E.W.; Vadas, S.L.; Wang, Yun.

    1990-04-01

    The possibility is considered that higher dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. Two separate models are analayzed. One is a very simple toy model consisting of higher dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of non-trivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a non-trivial potential for the radius of the internal space. It was found that extended inflation does not occur in these models. It was also found that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation.

  4. Extended inflation from higher-dimensional theories

    NASA Astrophysics Data System (ADS)

    Holman, Richard; Kolb, Edward W.; Vadas, Sharon L.; Wang, Yun

    1991-02-01

    We consider the possibility that higher-dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. We analyze two separate models. One is a very simple toy model consisting of higher-dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of nontrivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a nontrivial potential for the radius of the internal space. We find that extended inflation does not occur in these models. We also find that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation.

  5. Overview of the Cassini Extended Mission Trajectory

    NASA Technical Reports Server (NTRS)

    Buffington, Brent; Strange, Nathan; Smith, John

    2008-01-01

    Due to the highly successful execution of the Cassini-Huygens prime mission and the estimated propellant remaining at the conclusion of the prime mission, NASA Headquarters allocated funding for the development of a 2-year long Cassini extended mission. The resultant extended mission, stemming from 1.5 years of development, includes an additional 26 targeted Titan flybys, 9 close flybys of icy satellites, and 60 orbits about Saturn. This paper describes, in detail, the different phases of the Cassini extended mission and the associated design methodology, which attempted to maximize the number and quality of high-priority scientific objectives while minimizing the total delta v expenditure and adhering to mission-imposed constraints.

  6. Extended inflation from higher dimensional theories

    NASA Technical Reports Server (NTRS)

    Holman, Richard; Kolb, Edward W.; Vadas, Sharon L.; Wang, Yun

    1990-01-01

    The possibility is considered that higher dimensional theories may, upon reduction to four dimensions, allow extended inflation to occur. Two separate models are analayzed. One is a very simple toy model consisting of higher dimensional gravity coupled to a scalar field whose potential allows for a first-order phase transition. The other is a more sophisticated model incorporating the effects of non-trivial field configurations (monopole, Casimir, and fermion bilinear condensate effects) that yield a non-trivial potential for the radius of the internal space. It was found that extended inflation does not occur in these models. It was also found that the bubble nucleation rate in these theories is time dependent unlike the case in the original version of extended inflation.

  7. Extended range radiation dose-rate monitor

    DOEpatents

    Valentine, Kenneth H.

    1988-01-01

    An extended range dose-rate monitor is provided which utilizes the pulse pileup phenomenon that occurs in conventional counting systems to alter the dynamic response of the system to extend the dose-rate counting range. The current pulses from a solid-state detector generated by radiation events are amplified and shaped prior to applying the pulses to the input of a comparator. The comparator generates one logic pulse for each input pulse which exceeds the comparator reference threshold. These pulses are integrated and applied to a meter calibrated to indicate the measured dose-rate in response to the integrator output. A portion of the output signal from the integrator is fed back to vary the comparator reference threshold in proportion to the output count rate to extend the sensitive dynamic detection range by delaying the asymptotic approach of the integrator output toward full scale as measured by the meter.

  8. Extending Double Optical Gating to the Midinfrared

    NASA Astrophysics Data System (ADS)

    Gorman, Timothy; Camper, Antoine; Agostini, Pierre; Dimauro, Louis

    2015-05-01

    In the past decade there has been great interest in creating broadband isolated attosecond pulses (IAPs). Primarily these IAPs have been generated using Ti:Sapphire 800nm short pulses, namely through spatiotemporal gating with the attosecond lighthouse technique, amplitude gating, polarization gating, and double optical gating (DOG). Here we present theoretical calculations and experimental investigations into extending DOG to using a 2 μm driving wavelength, the benefits of which include extended harmonic cutoff and longer input driving pulse durations. It is proposed that broadband IAPs with cutoffs extending up to 250 eV can be generated in Argon by using >30 fs pulses from the passively-CEP stabilized 2 μm idler out of an optical parametric amplifier combined with a collinear DOG experimental setup.

  9. Clumpy and Extended Starbursts in the Brightest Unlensed Submillimeter Galaxies

    NASA Astrophysics Data System (ADS)

    Iono, Daisuke; Yun, Min S.; Aretxaga, Itziar; Hatsukade, Bunyo; Hughes, David; Ikarashi, Soh; Izumi, Takuma; Kawabe, Ryohei; Kohno, Kotaro; Lee, Minju; Matsuda, Yuichi; Nakanishi, Kouichiro; Saito, Toshiki; Tamura, Yoichi; Ueda, Junko; Umehata, Hideki; Wilson, Grant; Michiyama, Tomonari; Ando, Misaki

    2016-09-01

    The central structure in three of the brightest unlensed z = 3-4 submillimeter galaxies is investigated through 0.″015-0.″05 (120-360 pc) 860 μm continuum images obtained using the Atacama Large Millimeter/submillimeter Array (ALMA). The distribution in the central kiloparsec in AzTEC1 and AzTEC8 is extremely complex, and they are composed of multiple ˜200 pc clumps. AzTEC4 consists of two sources that are separated by ˜1.5 kpc, indicating a mid-stage merger. The peak star formation rate densities in the central clumps are ˜300-3000 M ⊙ yr-1 kpc-2, suggesting regions with extreme star formation near the Eddington limit. By comparing the flux obtained by ALMA and Submillimeter Array, we find that 68%-90% of the emission is extended (≳1 kpc) in AzTEC4 and 8. For AzTEC1, we identify at least 11 additional compact (˜200 pc) clumps in the extended 3-4 kpc region. Overall, the data presented here suggest that the luminosity surface densities observed at ≲150 pc scales are roughly similar to that observed in local ULIRGs, as in the eastern nucleus of Arp 220. Between 10% and 30% of the 860 μm continuum is concentrated in clumpy structures in the central kiloparsec, while the remaining flux is distributed over ≳1 kpc regions, some of which could also be clumpy. These sources can be explained by a rapid inflow of gas such as a merger of gas-rich galaxies, surrounded by extended and clumpy starbursts. However, the cold mode accretion model is not ruled out.

  10. Overview of the X-33 Extended Flight Test Range

    NASA Technical Reports Server (NTRS)

    Mackall, D.; Sakahara, R.; Kremer, S.

    1998-01-01

    On July 1, 1996, the National Aeronautics and Space Administration signed a Cooperative Agreement No. NCC8-115 with Lockheed Martin Skunk Works to develop and flight test the X-33, a scaled version of a reusable launch vehicle. The development of an Extended Test Range, with range instrumentation providing continuous vehicle communications from Edwards Air Force Base Ca. to landing at Malmstrom Air Force Base Montana, was required to flight test the mach 15 vehicle over 950 nautical miles. The cooperative agreement approach makes Lockheed Martin Skunk Works responsible for the X-33 program. When additional Government help was required, Lockheed "subcontracted" to NASA Field Centers for certain work. It was through this mechanism that Dryden Flight Research Center became responsible for the Extended Test Range. The Extended Test Range Requirements come from two main sources: 1) Range Safety and 2) Lockheed Martin Skunk Works. The range safety requirements were the most challenging to define and meet. The X-33 represents a vehicle that launches like a rocket, reenters the atmosphere and lands autonomously like an aircraft. Historically, rockets have been launched over the oceans to allow failed rockets to be destroyed using explosive devices. Such approaches had to be reconsidered for the X-33 flying over land. Numerous range requirements come from Lockheed Martin Skunk Works for interface definitions with the vehicle communication subsystems and the primary ground operations center, defined the Operations Control Center. Another area of considerable interest was the reentry plasma shield that causes "blackout" of the radio frequency signals, such as the range safety commands. Significant work was spent to analyze and model the blackout problem using a cooperative team of experts from across the country. The paper describes the Extended Test Range a, an unique Government/industry team of personnel and range assets was established to resolve design issues and

  11. Repatriation of US sources from Brazil

    SciTech Connect

    Tompkins, Andrew J

    2008-01-01

    IAEA's interest in excess and unwanted sealed sources extends back to when radium sources were a problem throughout the world. Sta11ing in 1994, world wide IAEA member states inventoried and consolidated radium (Ra)-226 sources. IAEA then trained Regional Teams in the conditioning of Ra-226 sealed sources for long term storage, which resulted in the Regional Teams conditioning about 14,000 radium sources. These sources remained in their respective IAEA member state locations. Regional teams were seen as a way to encourage member state (local) management of a world wide problem, as well as a more cost effective solution.

  12. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  13. Extending the ADM formalism to Weyl geometry

    NASA Astrophysics Data System (ADS)

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-01

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  14. NASA Orbiter Extended Nose Landing Gear

    NASA Technical Reports Server (NTRS)

    King, Steven R.; Jensen, Scott A.; Hansen, Christopher P.

    1999-01-01

    This paper discusses the design, development, test, and evaluation of a prototype Extended Nose Landing Gear (ENLG) for NASA's Space Shuttle orbiters. The ENLG is a proposed orbiter modification developed in-house at NASA's Johnson Space Center (JSC) by a joint government/industry team. It increases the orbiter's nose landing gear (NLG) length, thereby changing the vehicle's angle of attack during rollout, which lowers the aerodynamic forces on the vehicle. This, in combination with a dynamic elevon change, will lower the loads on the orbiter's main landing gear (MLG). The extension is accomplished by adding a telescoping section to the current NLG strut that will be pneumatically extended during NLG deployment.

  15. The Extended Mind: Coupling Environment and Brain

    NASA Astrophysics Data System (ADS)

    Vrobel, Susie

    2010-11-01

    This paper describes embodiment and cognitive extension as examples of strong anticipation as defined by Dubois. Clark and Chalmers formulated a thesis which states that parts of the environment, if coupled successfully, can become part of the extended mind. This coupling, be it deliberate or unintentional, shifts the observer-world boundary outwards when the observer encompasses parts of his environment. The resulting extended observer forms a new systemic whole, which consists of both the assimilated context and the recalibrated version of the original observer. Recalibration occurs when conditioning and adaptation lead to corresponding changes on the neural level, for instance, when an agent compensates for delays in a control loop. Plasticity is a prerequisite for any successful incorporation of external structures. However, uncoupled parts of the observer must remain inviolate in order to preserve the boundary. Neither the extended mind nor the core observer are absolute concepts. Depending on whether we focus on local-scale interactions or on large-scale behaviour, boundaries are formed at different interfacial cuts, which lead to either an endo- or an exo-perspective or endo- or exo-anticipation, respectively. For biological extended agents which undergo a transition from exo- to endo-states, a tell-tale sign of a successful exo-endo transition is invisibility. This invisibility occurs when the agent is no longer aware of the delay originally introduced into the control loop by the assimilated part of the environment. Explaining the world in terms of effective causality is not sufficient to account for extended minds. The latter require explanations in terms of final causation. For extended minds, this ordering principle comes in the shape of nested hierarchical layers. The interfaces of these layers may have merged for an endo-observer, whereas an exo-observer can make out the detailed structure, including artificially introduced delays. A sufficient

  16. Weak Lie symmetry and extended Lie algebra

    SciTech Connect

    Goenner, Hubert

    2013-04-15

    The concept of weak Lie motion (weak Lie symmetry) is introduced. Applications given exhibit a reduction of the usual symmetry, e.g., in the case of the rotation group. In this context, a particular generalization of Lie algebras is found ('extended Lie algebras') which turns out to be an involutive distribution or a simple example for a tangent Lie algebroid. Riemannian and Lorentz metrics can be introduced on such an algebroid through an extended Cartan-Killing form. Transformation groups from non-relativistic mechanics and quantum mechanics lead to such tangent Lie algebroids and to Lorentz geometries constructed on them (1-dimensional gravitational fields).

  17. Extending the ADM formalism to Weyl geometry

    SciTech Connect

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-26

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  18. Extending Program Resources: Meeting Necessity with Invention.

    ERIC Educational Resources Information Center

    Fuston, Judith; Hargens, Mark

    This document describes collaborative strategies used by one school guidance department that allow counselors to complete their designated work without extending their school day. One strategy involves pairing mentors with first-year counselors to help answer their questions. Another uses retired counselors as "substitutes" when regular counselors…

  19. Extended Learning Institute. Policies and Procedures Manual.

    ERIC Educational Resources Information Center

    Adams, Larry

    This manual describes the Extended Learning Institute (ELI) at John Tyler Community College in Virginia. The ELI is a comprehensive program of instruction using alternative delivery systems (e.g., television, print-based, radio, and newspapers). General procedures and policies are delineated in section I, including registration and student and…

  20. Some Remarks on the Extended Galilean Transformation.

    ERIC Educational Resources Information Center

    Greenberger, Daniel M.

    1979-01-01

    The extended Galilean transformation carries an inertial frame into a rigid frame with uniform spatial, but arbitrary translational acceleration. Besides being useful in discussing the equivalence principle, this transformation provides a physical interpretation for the theorem in nonrelativistic quantum mechanics, that we cannot coherently…

  1. Robotic extended pyelolithotomy for complete staghorn calculus.

    PubMed

    Sotelo, Rene; Astigueta, Juan Carlos; Giedelman, Camilo; de Andrade, Robert; Carmona, Oswaldo; Ramirez, Daniel; Clavijo, Rafael

    2010-08-01

    Staghorn stones represent a therapeutic challenge to urologists. We present our experience with laparoscopic extended pyelolithotomy for treatment of staghorn and complex renal calculi in highly selected cases. This approach provides the principles of open surgery with the advantages of minimally invasive surgery. We describe our experience with robot-assisted extended pyelolithotomy for complex coralliform calculi. Since January 2007, robotic extended pyelolithotomy has been performed by transperitoneal approach in two patients with complete coralliform lithiasis (calculi average size 8 cm). One patient had history of percutaneous nephrolithotomy. Demographic and operative data were collected. All procedures were technically successful without need for open conversion. Mean estimated blood loss was 175 ml (range 50-300 ml), and mean operative time was 150 min (range 120-150 min). A perinephric drain was employed in one patient with duration of 5 days. Postoperative imaging confirmed complete stone clearance. Robotic extended pyelolithotomy is a feasible and reproducible procedure for removal of complete and partial staghorn calculi in selected patients with complex nephrolithiasis. This approach might limit the role of open surgery for these calculi, but further publications with more cases are necessary to further define its utility.

  2. On energy conservation in extended magnetohydrodynamics

    SciTech Connect

    Kimura, Keiji; Morrison, P. J.

    2014-08-15

    A systematic study of energy conservation for extended magnetohydrodynamic models that include Hall terms and electron inertia is performed. It is observed that commonly used models do not conserve energy in the ideal limit, i.e., when viscosity and resistivity are neglected. In particular, a term in the momentum equation that is often neglected is seen to be needed for conservation of energy.

  3. Extended School Year. Information Capsule. Volume 0910

    ERIC Educational Resources Information Center

    Blazer, Christie

    2010-01-01

    Extended school years are being considered by districts around the country as educators search for new ways to raise student achievement. The addition of time to the school calendar is also supported by President Barack Obama, who recently stated that American students do not spend enough time in school. This Information Capsule addresses research…

  4. The Extended Family and Children's Educational Success

    ERIC Educational Resources Information Center

    Jaeger, Mads Meier

    2012-01-01

    Research on family background and educational success focuses almost exclusively on two generations: parents and children. This study argues that the extended family contributes significantly to the total effect of family background on educational success. Analyses using the Wisconsin Longitudinal Study show that, net of family factors shared by…

  5. Sulfur extended asphalt pavement evaluation: Executive summary

    NASA Astrophysics Data System (ADS)

    Mahoney, J. P.

    1982-09-01

    This summary report overviews two previously issued study reports. One report assesses The availability and pricing of sulfur with respect to sulfur extended asphalt (SEA) paving mixture is assessed. A laboratory oriented testing program which was principally used to examine the durability and aging characteristics of SEA paving mixtures is reported.

  6. Extending School Hours: A Capital Idea.

    ERIC Educational Resources Information Center

    Jones, John Hodge

    1995-01-01

    The Murfreesboro, Tennessee, City Schools have doubled the amount of time schools are open without raising taxes. Instead of going home to empty houses, kids participate in an extended school program offering over 100 courses in recreation, academics, arts, and life skills. Parents and organizations foot the costs; no child is excluded for…

  7. Extended Learning: What Are the States Doing?

    ERIC Educational Resources Information Center

    Brown, Cynthia G.

    2001-01-01

    The standards movement and family work schedules are major factors underpinning the expansion of extended learning opportunities. A recent report by the Council of Chief State School Officials details the development of afterschool and other programs in California, Illinois, Kentucky, Massachusetts, Minnesota, and Texas. (MLH)

  8. Extending Transitional Services to Former Foster Children

    ERIC Educational Resources Information Center

    Kerman, Ben; Barth, Richard P.; Wildfire, Judy

    2004-01-01

    This article describes what a private agency expended while addressing the transitional needs of former long-term foster youth and examines the association between expenditures and adult outcomes. Not all young adults accepted supports extended to them. In the sample, 41% of the young adults incurred expenses after age 19. Of those using supports,…

  9. Extendible column can be stowed on drum

    NASA Technical Reports Server (NTRS)

    Holtz, G. M.; Howard, E. A.

    1965-01-01

    Column formed from a series of segments held together by an internal spring or cable can be coiled on a drum or extended into a rigid structure. This storable coil is useful in boring for soil samples and supporting electrical and optical sensors.

  10. Fullerton Junior College Extended-Day Program.

    ERIC Educational Resources Information Center

    Meservy, Royal R.

    This paper describes in detail the administrative and operational organization of a program for 4,000 night students and 2,000 extended-day students. It outlines the duties of the Administrative Assistant in Instruction, who is responsible to the Dean of Instruction, Liberal Arts and to the Dean of Instruction, Technical Arts. It also gives a…

  11. Extended Learning Time: Research and Resources

    ERIC Educational Resources Information Center

    Stelow, Shawn; Holland, Jenifer Gager; Jackson, Rebecca

    2012-01-01

    In recent years policymakers have increasingly looked to Extended Learning Time (ELT) as a means of improving student outcomes. As a result, some school districts have increased academic time for students by adding time to the school day or days to the school year. In other communities, schools and community-based organizations have partnered to…

  12. Integrable extended van der Waals model

    NASA Astrophysics Data System (ADS)

    Giglio, Francesco; Landolfi, Giulio; Moro, Antonio

    2016-10-01

    Inspired by the recent developments in the study of the thermodynamics of van der Waals fluids via the theory of nonlinear conservation laws and the description of phase transitions in terms of classical (dissipative) shock waves, we propose a novel approach to the construction of multi-parameter generalisations of the van der Waals model. The theory of integrable nonlinear conservation laws still represents the inspiring framework. Starting from a macroscopic approach, a four parameter family of integrable extended van der Waals models is indeed constructed in such a way that the equation of state is a solution to an integrable nonlinear conservation law linearisable by a Cole-Hopf transformation. This family is further specified by the request that, in regime of high temperature, far from the critical region, the extended model reproduces asymptotically the standard van der Waals equation of state. We provide a detailed comparison of our extended model with two notable empirical models such as Peng-Robinson and Soave's modification of the Redlich-Kwong equations of state. We show that our extended van der Waals equation of state is compatible with both empirical models for a suitable choice of the free parameters and can be viewed as a master interpolating equation. The present approach also suggests that further generalisations can be obtained by including the class of dispersive and viscous-dispersive nonlinear conservation laws and could lead to a new type of thermodynamic phase transitions associated to nonclassical and dispersive shock waves.

  13. The inflation sector of extended inflation

    SciTech Connect

    Kolb, E.W. Chicago Univ., IL )

    1990-11-01

    In extended inflation the inflationary era is brought to a close by the process of percolation of true vacuum bubbles produced in a first-order phase transition. In this paper I discuss several effects that might obtain if the Universe undergoes an inflationary first-order phase transition. 17 refs.

  14. The inflation sector of extended inflation

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.

    1991-01-01

    In extended inflation, the inflationary era is brought to a close by the process of percolation of true vacuum bubbles produced in a first-order phase transition. This paper discusses several effects that might obtain if the universe undergoes an inflationary first-order phase transition.

  15. Adult Day Care--Extended Family.

    ERIC Educational Resources Information Center

    Smith, Bert Kruger

    This pamphlet describes a multi-purpose day-care center for the elderly in Abilene, Texas which is intended to fill the "extended family" role of offering companionship, medical attention, and other aspects of concern to older persons in the community. The goals of the program are as follows: (1) to keep individuals out of institutions as long as…

  16. Robotic extended pyelolithotomy for complete staghorn calculus.

    PubMed

    Sotelo, Rene; Astigueta, Juan Carlos; Giedelman, Camilo; de Andrade, Robert; Carmona, Oswaldo; Ramirez, Daniel; Clavijo, Rafael

    2010-08-01

    Staghorn stones represent a therapeutic challenge to urologists. We present our experience with laparoscopic extended pyelolithotomy for treatment of staghorn and complex renal calculi in highly selected cases. This approach provides the principles of open surgery with the advantages of minimally invasive surgery. We describe our experience with robot-assisted extended pyelolithotomy for complex coralliform calculi. Since January 2007, robotic extended pyelolithotomy has been performed by transperitoneal approach in two patients with complete coralliform lithiasis (calculi average size 8 cm). One patient had history of percutaneous nephrolithotomy. Demographic and operative data were collected. All procedures were technically successful without need for open conversion. Mean estimated blood loss was 175 ml (range 50-300 ml), and mean operative time was 150 min (range 120-150 min). A perinephric drain was employed in one patient with duration of 5 days. Postoperative imaging confirmed complete stone clearance. Robotic extended pyelolithotomy is a feasible and reproducible procedure for removal of complete and partial staghorn calculi in selected patients with complex nephrolithiasis. This approach might limit the role of open surgery for these calculi, but further publications with more cases are necessary to further define its utility. PMID:27628774

  17. Q-Method Extended Kalman Filter

    NASA Technical Reports Server (NTRS)

    Zanetti, Renato; Ainscough, Thomas; Christian, John; Spanos, Pol D.

    2012-01-01

    A new algorithm is proposed that smoothly integrates non-linear estimation of the attitude quaternion using Davenport s q-method and estimation of non-attitude states through an extended Kalman filter. The new method is compared to a similar existing algorithm showing its similarities and differences. The validity of the proposed approach is confirmed through numerical simulations.

  18. Extended Generalized Linear Latent and Mixed Model

    ERIC Educational Resources Information Center

    Segawa, Eisuke; Emery, Sherry; Curry, Susan J.

    2008-01-01

    The generalized linear latent and mixed modeling (GLLAMM framework) includes many models such as hierarchical and structural equation models. However, GLLAMM cannot currently accommodate some models because it does not allow some parameters to be random. GLLAMM is extended to overcome the limitation by adding a submodel that specifies a…

  19. 14 CFR 1274.207 - Extended agreements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Extended agreements. 1274.207 Section 1274.207 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COOPERATIVE AGREEMENTS WITH..., period of performance and funding levels; therefore, new proposals, certifications, and...

  20. 14 CFR 1274.207 - Extended agreements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Extended agreements. 1274.207 Section 1274.207 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COOPERATIVE AGREEMENTS WITH..., period of performance and funding levels; therefore, new proposals, certifications, and...

  1. 14 CFR 1274.207 - Extended agreements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Extended agreements. 1274.207 Section 1274.207 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COOPERATIVE AGREEMENTS WITH..., period of performance and funding levels; therefore, new proposals, certifications, and...

  2. Interpolation of the Extended Boolean Retrieval Model.

    ERIC Educational Resources Information Center

    Zanger, Daniel Z.

    2002-01-01

    Presents an interpolation theorem for an extended Boolean information retrieval model. Results show that whenever two or more documents are similarly ranked at any two points for a query containing exactly two terms, then they are similarly ranked at all points in between; and that results can fail for queries with more than two terms. (Author/LRW)

  3. Trigeminal schwannoma extending into the parapharyngeal space.

    PubMed

    Yumuşakhuylu, Ali Cemal; Sari, Murat; Topuz, Muhammet Fatih; Bağlam, Tekin; Binnetoğlu, Adem

    2014-07-01

    Parapharyngeal space tumors are very rarely seen, and surgical approach to these tumors has not been well established. Most of these tumors are benign and originated from salivary glands and neurogenic in nature. In this case, we report a patient who has a trigeminal schwannoma extending into the deep parapharyngeal space and explain our surgical approach.

  4. A Model for E-Education: Extended Teaching Spaces and Extended Learning Spaces

    ERIC Educational Resources Information Center

    Jung, Insung; Latchem, Colin

    2011-01-01

    The paper proposes a model for e-education in instruction, training, initiation and induction based upon the concept of extended teaching spaces involving execution, facilitation and liberation, and extended learning spaces used for acquisition, application and construction cemented by dialogue and reflection. The proposed model is based upon…

  5. Elaborated Odor Test for Extended Exposure

    NASA Technical Reports Server (NTRS)

    Buchanan, Vanessa D.; Henry, Emily J.; Mast, Dion J.; Harper, Susana A.; Beeson, Harold D.; Tapia, Alma S.

    2016-01-01

    Concerns were raised when incidental exposure to a proprietary bonding material revealed the material had an irritating odor. The NASA-STD-6001B document describes a supplemental test method option for programs to evaluate materials with odor concerns (Test 6, Odor Assessment). In addition to the supplemental standard odor assessment with less than 10 seconds of exposure, the NASA White Sands Test Facility (WSTF) Materials Flight Acceptance Testing section was requested to perform an odor test with an extended duration to evaluate effects of an extended exposure and to more closely simulate realistic exposure scenarios. With approval from the NASA Johnson Space Center Industrial Hygienist, WSTF developed a 15-minute odor test method. WSTF performed this extended-duration odor test to evaluate the odor and physical effects of the bonding material configured between two aluminum plates, after the safety of the gas was verified via toxicity analysis per NASA-STD-6001B Test 7, Determination of Offgassed Products. During extended-duration testing, odor panel members were arranged near the test material in a small room with the air handlers and doors closed to minimize dilution. The odor panel members wafted gas toward themselves and recorded their individual assessments of odor and physical effects at various intervals during the 15-minute exposure and posttest. A posttest interview was conducted to obtain further information. Testing was effective in providing data for comparison and selection of an optimal offgassing and odor containment configuration. The developed test method for extended exposure is proposed as a useful tool for further evaluating materials with identified odors of concern if continued use of the material is anticipated.

  6. ION SOURCE

    DOEpatents

    Leland, W.T.

    1960-01-01

    The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

  7. Crowd Sourcing.

    PubMed

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish.

  8. Crowd Sourcing.

    PubMed

    Baum, Neil

    2016-01-01

    The Internet has contributed new words and slang to our daily vernacular. A few terms, such as tweeting, texting, sexting, blogging, and googling, have become common in most vocabularies and in many languages, and are now included in the dictionary. A new buzzword making the rounds in industry is crowd sourcing, which involves outsourcing an activity, task, or problem by sending it to people or groups outside a business or a practice. Crowd sourcing allows doctors and practices to tap the wisdom of many instead of relying only on the few members of their close-knit group. This article defines "crowd sourcing," offers examples, and explains how to get started with this approach that can increase your ability to finish a task or solve problems that you don't have the time or expertise to accomplish. PMID:27039640

  9. RADIATION SOURCES

    DOEpatents

    Brucer, M.H.

    1958-04-15

    A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

  10. Extending the ICRF to Higher Radio Frequencies: 24 and 43 GHz Astrometry

    NASA Technical Reports Server (NTRS)

    Jacobs, Christopher S.; Charlot, Patrick; Fomalont, Ed B.; Gordon, David; Lanyi, Gabor E.; Ma, Chopo; Naudet, Charles J.; Sovers, Ojars J.; Zhang, Li-Wei D.

    2004-01-01

    We present imaging results and source structure analysis of extragalactic radio sources observed using the Very Long Baseline Array (VLBA) at 24 GHz and 43 GHz as part of an ongoing NASA, USNO, NRAO and Bordeaux Observatory collaboration to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies. The K/Q-band image database now includes images of 108 sources at 43 GHz (Q-band) and images of 230 sources at 24 GHz (K-band). Preliminary analysis of the observations taken to date shows that the sources are generally more compact as one goes from the ICRF frequency of 8.4 GHz to 24 GHz. This result is consistent with the standard theory of compact extragalactic radio sources and suggests that reference frames defined at these higher radio frequencies will be less susceptible to the effects of intrinsic source structure than those defined at lower frequencies.

  11. Constraining extended gamma-ray emission from galaxy clusters

    NASA Astrophysics Data System (ADS)

    Han, Jiaxin; Frenk, Carlos S.; Eke, Vincent R.; Gao, Liang; White, Simon D. M.; Boyarsky, Alexey; Malyshev, Denys; Ruchayskiy, Oleg

    2012-12-01

    Cold dark matter models predict the existence of a large number of substructures within dark matter haloes. If the cold dark matter consists of weakly interacting massive particles, their annihilation within these substructures could lead to diffuse GeV emission that would dominate the annihilation signal of the host halo. In this work we search for GeV emission from three nearby galaxy clusters: Coma, Virgo and Fornax. We first remove known extragalactic and galactic diffuse gamma-ray backgrounds and point sources from the Fermi 2-yr catalogue and find a significant residual diffuse emission in all three clusters. We then investigate whether this emission is due to (i) unresolved point sources, (ii) dark matter annihilation or (iii) cosmic rays (CR). Using 45 months of Fermi-Large Area Telescope (Fermi-LAT) data we detect several new point sources (not present in the Fermi 2-yr point source catalogue) which contaminate the signal previously analysed by Han et al. Including these and accounting for the effects of undetected point sources, we find no significant detection of extended emission from the three clusters studied. Instead, we determine upper limits on emission due to dark matter annihilation and CR. For Fornax and Virgo, the limits on CR emission are consistent with theoretical models, but for Coma the upper limit is a factor of 2 below the theoretical expectation. Allowing for systematic uncertainties associated with the treatment of CR, the upper limits on the cross-section for dark matter annihilation from our clusters are more stringent than those from analyses of dwarf galaxies in the Milky Way. Adopting a boost factor of ˜103 from subhaloes on cluster luminosity as suggested by recent theoretical models, we rule out the thermal cross-section for supersymmetric dark matter particles for masses as large as 100 GeV (depending on the annihilation channel).

  12. THE EXTENDED ENVIRONMENT OF M17: A STAR FORMATION HISTORY

    SciTech Connect

    Povich, Matthew S.; Churchwell, Ed; Babler, Brian L.; Meade, Marilyn R.; Bieging, John H.; Kang, Miju; Kulesa, Craig A.; Whitney, Barbara A.; Brogan, Crystal L.; Cohen, Martin; Indebetouw, Remy; Robitaille, Thomas P.

    2009-05-10

    M17 is one of the youngest and most massive nearby star-formation regions in the Galaxy. It features a bright H II region erupting as a blister from the side of a giant molecular cloud (GMC). Combining photometry from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) with complementary infrared (IR) surveys, we identify candidate young stellar objects (YSOs) throughout a 1.{sup 0}5 x 1{sup 0} field that includes the M17 complex. The long sightline through the Galaxy behind M17 creates significant contamination in our YSO sample from unassociated sources with similar IR colors. Removing contaminants, we produce a highly reliable catalog of 96 candidate YSOs with a high probability of association with the M17 complex. We fit model spectral energy distributions to these sources and constrain their physical properties. Extrapolating the mass function of 62 intermediate-mass YSOs (M {sub *} > 3 M {sub sun}), we estimate that >1000 stars are in the process of forming in the extended outer regions of M17. The remaining 34 candidate YSOs are found in a 0.17 deg{sup 2} field containing the well-studied M17 H II region and photodissociation region (PDR), where bright diffuse mid-IR emission drastically reduces the sensitivity of the GLIMPSE point-source detections. By inspecting IR survey images from IRAS and GLIMPSE, we find that M17 lies on the rim of a large shell structure {approx}0.{sup 0}5 in diameter ({approx}20 pc at 2.1 kpc). We present maps of {sup 12}CO and {sup 13}CO (J = 2 {yields} 1) emission observed with the Heinrich Hertz Telescope. The CO emission shows that the shell is a coherent, kinematic structure associated with M17, centered at v = 19 km s{sup -1}. The shell is an extended bubble outlining the PDR of a faint, diffuse H II region several Myr old. We identify a group of candidate ionizing stars within the bubble. YSOs in our catalog are concentrated around the bubble rim, providing evidence that massive star formation has

  13. The Extended Environment of M17: A Star Formation History

    NASA Astrophysics Data System (ADS)

    Povich, Matthew S.; Churchwell, Ed; Bieging, John H.; Kang, Miju; Whitney, Barbara A.; Brogan, Crystal L.; Kulesa, Craig A.; Cohen, Martin; Babler, Brian L.; Indebetouw, Rémy; Meade, Marilyn R.; Robitaille, Thomas P.

    2009-05-01

    M17 is one of the youngest and most massive nearby star-formation regions in the Galaxy. It features a bright H II region erupting as a blister from the side of a giant molecular cloud (GMC). Combining photometry from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) with complementary infrared (IR) surveys, we identify candidate young stellar objects (YSOs) throughout a 1fdg5 × 1° field that includes the M17 complex. The long sightline through the Galaxy behind M17 creates significant contamination in our YSO sample from unassociated sources with similar IR colors. Removing contaminants, we produce a highly reliable catalog of 96 candidate YSOs with a high probability of association with the M17 complex. We fit model spectral energy distributions to these sources and constrain their physical properties. Extrapolating the mass function of 62 intermediate-mass YSOs (M sstarf > 3 M sun), we estimate that >1000 stars are in the process of forming in the extended outer regions of M17. The remaining 34 candidate YSOs are found in a 0.17 deg2 field containing the well-studied M17 H II region and photodissociation region (PDR), where bright diffuse mid-IR emission drastically reduces the sensitivity of the GLIMPSE point-source detections. By inspecting IR survey images from IRAS and GLIMPSE, we find that M17 lies on the rim of a large shell structure ~0fdg5 in diameter (~20 pc at 2.1 kpc). We present maps of 12CO and 13CO (J = 2 → 1) emission observed with the Heinrich Hertz Telescope. The CO emission shows that the shell is a coherent, kinematic structure associated with M17, centered at v = 19 km s-1. The shell is an extended bubble outlining the PDR of a faint, diffuse H II region several Myr old. We identify a group of candidate ionizing stars within the bubble. YSOs in our catalog are concentrated around the bubble rim, providing evidence that massive star formation has been triggered by the expansion of the bubble. The formation of

  14. Planning for Extended Hours: A Survey of Practice.

    ERIC Educational Resources Information Center

    Despines, Janine

    2001-01-01

    Discusses extended hours of operation for school library media centers and describes how to plan for them. Considers benefits of extended hours; planning questions; staffing, including volunteers; costs and funding; security; and patron use of extended hours. (LRW)

  15. Superluminal sources.

    PubMed Central

    Vermeulen, R C

    1995-01-01

    Predictions for the apparent velocity statistics under simple beaming models are presented and compared to the observations. The potential applications for tests of unification models and for cosmology (source counts, measurements of the Hubble constant H0 and the deceleration parameter q0) are discussed. First results from a large homogeneous survey are presented. The data do not show compelling evidence for the existence of intrinsically different populations of galaxies, BL Lacertae objects, or quasars. Apparent velocities betaapp in the range 1-5 h-1, where h = H0/100 km.s-1.Mpc-1 [1 megaparsec (Mpc) = 3.09 x 10(22) m], occur with roughly equal frequency; higher values, up to betaapp = 10 h-1, are rather more scarce than appeared to be the case from earlier work, which evidently concentrated on sources that are not representative of the general population. The betaapp distribution suggests that there might be a skewed distribution of Lorentz factors over the sample, with a peak at gammab approximately 2 h-1 and a tail up to at least gammab approximately 10 h-1. There appears to be a clearly rising upper envelope to the betaapp distribution when plotted as a function of observed 5-GHz luminosity; a combination of source counts and the apparent velocity statistics in a larger sample could provide much insight into the properties of radio jet sources. PMID:11607604

  16. Photoelectron imaging of cells: photoconductivity extends the range of applicability.

    PubMed Central

    Habliston, D L; Hedberg, K K; Birrell, G B; Rempfer, G F; Griffith, O H

    1995-01-01

    Photoelectron imaging is a sensitive surface technique in which photons are used to excite electron emission. This novel method has been applied successfully in studies of relatively flat cultured cells, viruses, and protein-DNA complexes. However, rounded-up cell types such as tumor cells frequently are more difficult to image. By comparing photoelectron images of uncoated and metal-coated MCF-7 human breast carcinoma cells, it is shown that the problem is specimen charging rather than a fundamental limitation of the electron imaging process. This is confirmed by emission current measurements on uncoated monolayers of MCF-7 carcinoma cells and flatter, normal Wi-38 fibroblasts. We report here that sample charging in photoelectron microscopy can be eliminated in most specimens by simultaneous use of two light sources--the standard UV excitation source (e.g., 254 nm) and a longer wavelength light source (e.g., 325 nm). The reduction in sample charging results largely from enhanced photoconduction in the bulk sample and greatly extends the range of cells that can be examined by photoelectron imaging. The contributions of photoconductivity, the electric field of the imaging system, and the short escape depths of the photoelectrons combine to make photoelectron imaging a uniquely sensitive technique for the study of biological surfaces. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 PMID:8534832

  17. Extending resolution limits of EUV resist materials

    NASA Astrophysics Data System (ADS)

    Krysak, Marie; Leeson, Michael; Han, Eungnak; Blackwell, James; Harlson, Shane

    2015-03-01

    Extreme ultraviolet lithography (EUVL) technology continues to progress and remains a viable candidate for next generation lithography1, which drives the need for EUV resists capable of high resolution with high sensitivity and low LWR. While chemically amplified resists (CARs) have demonstrated the ability to pattern 12nm half-pitch features2, pattern collapse continues to limit their ultimate resolution. We have taken multiple approaches to extend resist capabilities past these limits. Recent results in pattern collapse mitigation using a resist encapsulation and etch back strategy will be discussed. We continue to investigate EUV patterning of semi-inorganic resists to simultaneously increase EUV photon absorption and extend mechanical strength beyond CAR capabilities. The limitations of metal oxide-based nanoparticle photoresists have been investigated, and have provided key insights to further understanding the mechanism of this class of materials.

  18. Synchronization in networks of spatially extended systems

    SciTech Connect

    Filatova, Anastasiya E.; Hramov, Alexander E.; Koronovskii, Alexey A.; Boccaletti, Stefano

    2008-06-15

    Synchronization processes in networks of spatially extended dynamical systems are analytically and numerically studied. We focus on the relevant case of networks whose elements (or nodes) are spatially extended dynamical systems, with the nodes being connected with each other by scalar signals. The stability of the synchronous spatio-temporal state for a generic network is analytically assessed by means of an extension of the master stability function approach. We find an excellent agreement between the theoretical predictions and the data obtained by means of numerical calculations. The efficiency and reliability of this method is illustrated numerically with networks of beam-plasma chaotic systems (Pierce diodes). We discuss also how the revealed regularities are expected to take place in other relevant physical and biological circumstances.

  19. Extended target recognition in cognitive radar networks.

    PubMed

    Wei, Yimin; Meng, Huadong; Liu, Yimin; Wang, Xiqin

    2010-01-01

    We address the problem of adaptive waveform design for extended target recognition in cognitive radar networks. A closed-loop active target recognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches.

  20. Junction conditions in extended Teleparallel gravities

    SciTech Connect

    De la Cruz-Dombriz, Álvaro; Dunsby, Peter K.S.; Sáez-Gómez, Diego E-mail: peter.dunsby@uct.ac.za

    2014-12-01

    In the context of extended Teleparallel gravity theories, we address the issue of junction conditions required to guarantee the correct matching of different regions of spacetime. In the absence of shells/branes, these conditions turn out to be more restrictive than their counterparts in General Relativity as in other extended theories of gravity. In fact, the general junction conditions on the matching hypersurfaces depend on the underlying theory and a new condition on the induced tetrads in order to avoid delta-like distributions in the field equations. This result imposes strict consequences on the viability of standard solutions such as the Einstein-Straus-like construction. We find that the continuity of the scalar torsion is required in order to recover the usual General Relativity results.

  1. Extended Lagrangian free energy molecular dynamics.

    PubMed

    Niklasson, Anders M N; Steneteg, Peter; Bock, Nicolas

    2011-10-28

    Extended free energy Lagrangians are proposed for first principles molecular dynamics simulations at finite electronic temperatures for plane-wave pseudopotential and local orbital density matrix-based calculations. Thanks to the extended Lagrangian description, the electronic degrees of freedom can be integrated by stable geometric schemes that conserve the free energy. For the local orbital representations both the nuclear and electronic forces have simple and numerically efficient expressions that are well suited for reduced complexity calculations. A rapidly converging recursive Fermi operator expansion method that does not require the calculation of eigenvalues and eigenfunctions for the construction of the fractionally occupied density matrix is discussed. An efficient expression for the Pulay force that is valid also for density matrices with fractional occupation occurring at finite electronic temperatures is also demonstrated.

  2. Charged local defects in extended systems

    NASA Astrophysics Data System (ADS)

    Schultz, Peter A.

    2000-03-01

    The conventional approach to treating charged defects in extended systems in first principles calculations is via the supercell approximation using a neutralizing jellium background charge. I explicitly demonstrate shortcomings of this standard appoach and show that the resulting errors in the electrostatic potential energy surface are comparable to band gaps energies, for supercell sizes typically used in defect calculations. I present an alternate scheme, generalized from the local moment counter-charge method [P.A. Schultz, Phys. Rev. B 60, 1551 (1999)], that gives the correct electrostatic potential in the vicinity of a defect, via a mixed boundary condition approach. As examples, I present results of first principles calculations for charged defects in extended systems.

  3. Extended ion pumped vacuum friction test

    NASA Technical Reports Server (NTRS)

    Hammel, R. L.

    1971-01-01

    Boundary layer friction data under ion pumped vacuum was taken for sixteen material couples. The test series was an extension of a previous study of the effects of modified ion pumped environments. Sliding distances imposed in the present effort greatly exceeded any studied in the previous contiguous, flight or ground tests. Wear out of specific couples, in particular, thin film lubricants was noted. The behavior of the test hardware including wear out of the mechanisms was noted. As a result, the impact of test interruption was observed for several test couples. Recovery of the friction upon re-establishing sliding in vacuum was generally rapid. The results of the extended sliding study reinforce the previous conclusion that sliding distance (mechanical history) is the primary factor in establishing the force limiting boundary layer friction. General friction value under the extended sliding confirm those observed in previous orbital and the related ground test studies.

  4. Optimizing Extender Code for NCSX Analyses

    SciTech Connect

    M. Richman, S. Ethier, and N. Pomphrey

    2008-01-22

    Extender is a parallel C++ code for calculating the magnetic field in the vacuum region of a stellarator. The code was optimized for speed and augmented with tools to maintain a specialized NetCDF database. Two parallel algorithms were examined. An even-block work-distribution scheme was comparable in performance to a master-slave scheme. Large speedup factors were achieved by representing the plasma surface with a spline rather than Fourier series. The accuracy of this representation and the resulting calculations relied on the density of the spline mesh. The Fortran 90 module db access was written to make it easy to store Extender output in a manageable database. New or updated data can be added to existing databases. A generalized PBS job script handles the generation of a database from scratch

  5. Extended hydrogen-bonded structures of phosphatidylethanolamine.

    PubMed

    Sen, A; Yang, P W; Mantsch, H H; Hui, S W

    1988-06-01

    The structure of phosphatidylethanolamine in pure dry hexane was studied. Viscosity measurements show that the hexane solution of PE has a very high viscosity, while freeze fracture electron microscopy revealed extensive fibre-like structures. These extended structures are disrupted by the addition of small amounts of water or organic solvents which are capable of hydrogen-bonding. The Fourier transform infrared spectra of the lipid solutions in dry and hydrated hexane show considerable differences in the phosphate and ethanolamine absorption bands, and demonstrate that the viscous fibre-like structures formed by phosphatidylethanolamine in dry hexane consist of extended intermolecular hydrogen-bonds, similar to those found in the solid lipid, with the ammonium group as the hydrogen-donor and the phosphate group as the hydrogen-acceptor. The high viscosity is not observed in hexane solution of phosphatidylcholine.

  6. Extended continuous-wave supercontinuum generation in a low-water-loss holey fiber

    NASA Astrophysics Data System (ADS)

    Travers, J. C.; Kennedy, R. E.; Popov, S. V.; Taylor, J. R.; Sabert, H.; Mangan, B.

    2005-08-01

    We report on the development of a 2.5 μm core photonic crystal fiber with a substantially reduced water-peak loss around 1.38 μm, which allows extended Raman-soliton supercontinuum generation up to 1.55 μm with a cw ytterbium fiber laser pump source. The resulting broadband, high-spectral-power-density, low-coherence light source can be employed for advanced, submicrometer resolution optical coherence tomography.

  7. Extended continuous-wave supercontinuum generation in a low-water-loss holey fiber.

    PubMed

    Travers, J C; Kennedy, R E; Popov, S V; Taylor, J R; Sabert, H; Mangan, B

    2005-08-01

    We report on the development of a 2.5 microm core photonic crystal fiber with a substantially reduced water-peak loss around 1.38 microm, which allows extended Raman-soliton supercontinuum generation up to 1.55 microm with a cw ytterbium fiber laser pump source. The resulting broadband, high-spectral-power-density, low-coherence light source can be employed for advanced, submicrometer resolution optical coherence tomography. PMID:16092225

  8. From Self-Organized to Extended Criticality

    PubMed Central

    Lovecchio, Elisa; Allegrini, Paolo; Geneston, Elvis; West, Bruce J.; Grigolini, Paolo

    2012-01-01

    We address the issue of criticality that is attracting the attention of an increasing number of neurophysiologists. Our main purpose is to establish the specific nature of some dynamical processes that although physically different, are usually termed as “critical,” and we focus on those characterized by the cooperative interaction of many units. We notice that the term “criticality” has been adopted to denote both noise-induced phase transitions and Self-Organized Criticality (SOC) with no clear connection with the traditional phase transitions, namely the transformation of a thermodynamic system from one state of matter to another. We notice the recent attractive proposal of extended criticality advocated by Bailly and Longo, which is realized through a wide set of critical points rather than emerging as a singularity from a unique value of the control parameter. We study a set of cooperatively firing neurons and we show that for an extended set of interaction couplings the system exhibits a form of temporal complexity similar to that emerging at criticality from ordinary phase transitions. This extended criticality regime is characterized by three main properties: (i) In the ideal limiting case of infinitely large time period, temporal complexity corresponds to Mittag-Leffler complexity; (ii) For large values of the interaction coupling the periodic nature of the process becomes predominant while maintaining to some extent, in the intermediate time asymptotic region, the signature of complexity; (iii) Focusing our attention on firing neuron avalanches, we find two of the popular SOC properties, namely the power indexes 2 and 1.5 respectively for time length and for the intensity of the avalanches. We derive the main conclusion that SOC emerges from extended criticality, thereby explaining the experimental observation of Plenz and Beggs: avalanches occur in time with surprisingly regularity, in apparent conflict with the temporal complexity of physical

  9. Extending The Shelf Life Of Blood Platelets

    NASA Technical Reports Server (NTRS)

    Surgenor, Douglas M.

    1988-01-01

    New method of storing human blood platelets extends vitality for transfusions. Packaged as suspension in sterile liquid in plastic blood bags. Each bag placed between pair of plastic grids, and rubberbands placed around sandwich thus formed to hold together. Stored upright in open air or in container through which air pumped at rate of at least 45 L/min. Ensures that platelets receive ample oxygen and expiratory carbon dioxide form platelets removed before pH drops to harmful levels.

  10. Analytical satellite theory in extended phase space

    NASA Technical Reports Server (NTRS)

    Bond, V.; Broucke, R.

    1980-01-01

    It is noted that a satellite theory, based on extended phase space and on the true anomaly, was introduced by Scheifele (1970). In the present paper a simple canonical transformation is shown that makes the transition from the classical Delaunay elements to the Scheifele variables. It is stressed that neither spherical coordinates nor Hamilton-Jacobi theory is used. Finally, attention is given to the meaning of the new variables, especially the use of the true anomaly as one of the variables.

  11. Analytical satellite theory in extended phase space

    NASA Astrophysics Data System (ADS)

    Bond, V.; Broucke, R.

    1980-05-01

    It is noted that a satellite theory, based on extended phase space and on the true anomaly, was introduced by Scheifele (1970). In the present paper a simple canonical transformation is shown that makes the transition from the classical Delaunay elements to the Scheifele variables. It is stressed that neither spherical coordinates nor Hamilton-Jacobi theory is used. Finally, attention is given to the meaning of the new variables, especially the use of the true anomaly as one of the variables.

  12. Rugged, Tunable Extended-Cavity Diode Laser

    NASA Technical Reports Server (NTRS)

    Moore, Donald; Brinza, David; Seidel, David; Klipstein, William; Choi, Dong Ho; Le, Lam; Zhang, Guangzhi; Iniguez, Roberto; Tang, Wade

    2007-01-01

    A rugged, tunable extended-cavity diode laser (ECDL) has been developed to satisfy stringent requirements for frequency stability, notably including low sensitivity to vibration. This laser is designed specifically for use in an atomic-clock experiment to be performed aboard the International Space Station (ISS). Lasers of similar design would be suitable for use in terrestrial laboratories engaged in atomic-clock and atomic-physics research.

  13. Astrophysical constraints on extended gravity models

    SciTech Connect

    Lambiase, Gaetano; Stabile, Antonio; Sakellariadou, Mairi; Stabile, Arturo E-mail: mairi.sakellariadou@kcl.ac.uk E-mail: arturo.stabile@gmail.com

    2015-07-01

    We investigate the propagation of gravitational waves in the context of fourth order gravity nonminimally coupled to a massive scalar field. Using the damping of the orbital period of coalescing stellar binary systems, we impose constraints on the free parameters of extended gravity models. In particular, we find that the variation of the orbital period is a function of three mass scales which depend on the free parameters of the model under consideration; we can constrain these mass scales from current observational data.

  14. THE EXTENDED OPTICAL DISK OF M101

    SciTech Connect

    Mihos, J. Christopher; Harding, Paul; Spengler, Chelsea E.; Rudick, Craig S.; Feldmeier, John J. E-mail: paul.harding@case.edu E-mail: craig.rudick@phys.ethz.ch

    2013-01-10

    We have used deep, wide-field optical imaging to study the faint outskirts of the luminous spiral galaxy M101 (NGC 5457) as well as its surrounding environment. Over 6 deg{sup 2}, our imaging has a limiting surface brightness of {mu} {sub B} {approx} 29.5 mag arcsec{sup -2}, and has revealed the stellar structure of M101's disk out to nearly 25' (50 kpc), 3 times our measured R {sub 25} isophotal size of the optical disk. At these radii, the well-known asymmetry of the inner disk slews 180 Degree-Sign , resulting in an asymmetric plume of light at large radius which follows the very extended H I disk to the northeast of M101. This plume has very blue colors (B - V {approx} 0.2), suggesting that it is the somewhat more evolved (few hundred Myr to {approx}1 Gyr) counterpart of the young far-ultraviolet emitting population traced by Galaxy Evolution Explorer imaging. We also detect another, redder spur of extended light to the east of the disk, and both structures are reminiscent of features produced during fly-by galaxy interactions. However, we see no evidence of very extended tidal tails around M101 or any of its companions which might be expected from a recent encounter with a massive companion. We consider the properties of M101's outer disk in light of possible past interactions with the nearby companion galaxies NGC 5477 and NGC 5474. The detection of optical starlight at such large radii gives us the ability to study star formation histories and stellar populations in outer disks over longer timescales than those traced by the UV or H{alpha} emitting populations. Our data suggest an ongoing buildup of M101's outer disk due to encounters in the group environment triggering extended star formation and tidal heating of existing disk populations.

  15. Extended Corannulenes: Aromatic Bowl/Sheet Hybridization.

    PubMed

    Dutta, Amit K; Linden, Anthony; Zoppi, Laura; Baldridge, Kim K; Siegel, Jay S

    2015-09-01

    Among sheet/sheet polynuclear aromatic hydrocarbon (PAH) hybrids, a buckybowl-graphene hybrid has been used as a model to explore the effects of physical properties of PAHs with distinct planar and bowl regions. Activation of a C(Ar)-F bond was used to synthesize this corannulene/graphenic hybrid. Photophysical and voltammetric studies together with high-level computations revealed curvature and extended π-effects on the properties of these materials. PMID:26216746

  16. Extended Temperature Solar Cell Technology Development

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Jenkins, Phillip; Scheiman, David; Rafaelle, Ryne

    2004-01-01

    Future NASA missions will require solar cells to operate both in regimes closer to the sun, and farther from the sun, where the operating temperatures will be higher and lower than standard operational conditions. NASA Glenn is engaged in testing solar cells under extended temperature ranges, developing theoretical models of cell operation as a function of temperature, and in developing technology for improving the performance of solar cells for both high and low temperature operation.

  17. Hybrid functionals applied to extended systems

    NASA Astrophysics Data System (ADS)

    Marsman, M.; Paier, J.; Stroppa, A.; Kresse, G.

    2008-02-01

    We present an overview of the description of structural, thermochemical, and electronic properties of extended systems using several well known hybrid Hartree-Fock/density-functional-theory functionals (PBE0, HSE03, and B3LYP). In addition we address a few aspects of the evaluation of the Hartree-Fock exchange interactions in reciprocal space, relevant to all methods that employ a plane wave basis set and periodic boundary conditions.

  18. Photovoltaic device having an extended PN junction

    NASA Technical Reports Server (NTRS)

    D'Aiello, Robert Vincent (Inventor)

    1978-01-01

    A photovoltaic device having essentially only a body of semiconductor material having a first region of one conductivity type in contact with a second region of the opposite conductivity type, forming a portion of the device PN junction therebetween. A plurality of pocket regions of the same conductivity type as the first region extend into the second region thereby further defining a portion of the PN junction in the second region.

  19. Extended Decentralized Linear-Quadratic-Gaussian Control

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell

    2000-01-01

    A straightforward extension of a solution to the decentralized linear-Quadratic-Gaussian problem is proposed that allows its use for commonly encountered classes of problems that are currently solved with the extended Kalman filter. This extension allows the system to be partitioned in such a way as to exclude the nonlinearities from the essential algebraic relationships that allow the estimation and control to be optimally decentralized.

  20. Origin of density fluctuations in extended inflation

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Salopek, David S.; Turner, Michael S.

    1990-01-01

    The density fluctuations (both curvature and isocurvature) that arise due to quantum fluctuations in a simple model of extended inflation based upon the Jordan-Brans-Dicke theory are calculated. Curvature fluctuations arise due to quantum fluctuations in the Brans-Dicke field, in general have a nonscale-invariant spectrum, and can have an amplitude that is cosmologically acceptable and interesting without having to tune any coupling constant to a very small value. The density perturbations that arise due to the inflation field are subdominant. If there are other massless fields in the theory, e.g., an axion or an ilion, then isocurvature fluctuations arise in these fields too. Production of gravitational waves and the massless particles associated with excitations of the Brans-Dicke field are also discussed. Several attempts at more realistic models of extended inflation are also analyzed. The importance of the Einstein conformal frame in calculating curvature fluctuations is emphasized. When viewed in this frame, extended inflation closely resembles slow-rollover inflation with an exponential potential and the usual formula for the amplitude of curvature perturbations applies.

  1. On extended thermonuclear functions through pathway model

    NASA Astrophysics Data System (ADS)

    Kumar, Dilip

    when α → 1. The beauty of the result is that these different families of three different functional forms are covered through the pathway parameter α. In a physical set up if f (x) in (3) is the stable or limiting form, the Maxwell-Boltzmann approach to thermonuclear functions, then f (x) in (1) and (2) will contain a large variety of unstable or chaotic situations which will all tend to (3) in the limit. Thus we get a clear idea of all the stable and unstable situations around the Maxwell-Boltzmann approach. Thus the current theory is given a mathematical extension and physical interpretations can be found to situations in (1) and (2). Incidently Tsallis statistics is a special case of (1) for γ = 0, a = 1, δ = 1, η = 1. The Beck-Cohen superstatistics, discussed in current statistical mechanics literature is a special case of (2) for a = 1, η = 1, α > 1. The main purpose of the present paper is to investigate in some more detail, mathematically, the extended thermonuclear functions for Maxwell-Boltzmann statistics and in the cut-off case. The extended thermonuclear functions will be evaluated in closed form for all convenient values of the parameter by means of residue calculus. A comparison of the standard thermonuclear functions with the extended thermonuclear functions is also done. The results and derivations in this paper are new and these will be of interest to physicists, mathematicians, probabilists, and statisticians.

  2. Inviscid Analysis of Extended Formation Flight

    NASA Technical Reports Server (NTRS)

    Kless, James; Aftosmis, Michael J.; Ning, Simeon Andrew; Nemec, Marian

    2012-01-01

    Flying airplanes in extended formations, with separation distances of tens of wingspans, significantly improves safety while maintaining most of the fuel savings achieved in close formations. The present study investigates the impact of roll trim and compressibility at fixed lift coefficient on the benefits of extended formation flight. An Euler solver with adjoint-based mesh refinement combined with a wake propagation model is used to analyze a two-body echelon formation at a separation distance of 30 spans. Two geometries are examined: a simple wing and a wing-body geometry. Energy savings, quantified by both formation drag fraction and span efficiency factor, are investigated at subsonic and transonic speeds for a matrix of vortex locations. The results show that at fixed lift and trimmed for roll, the optimal location of vortex impingement is about 10% inboard of the trailing airplane s wing-tip. Interestingly, early results show the variation in drag fraction reduction is small in the neighborhood of the optimal position. Over 90% of energy benefits can be obtained with a 5% variation in transverse and 10% variation in crossflow directions. Early results suggest control surface deflections required to achieve trim reduce the benefits of formation flight by 3-5% at subsonic speeds. The final paper will include transonic effects and trim on extended formation flight drag benefits.

  3. Source Inversion Validation: Quantifying Uncertainties in Earthquake Source Inversions

    NASA Astrophysics Data System (ADS)

    Mai, P. M.; Page, M. T.; Schorlemmer, D.

    2010-12-01

    Earthquake source inversions image the spatio-temporal rupture evolution on one or more fault planes using seismic and/or geodetic data. Source inversion methods thus represent an important research tool in seismology to unravel the complexity of earthquake ruptures. Subsequently, source-inversion results are used to study earthquake mechanics, to develop spontaneous dynamic rupture models, to build models for generating rupture realizations for ground-motion simulations, and to perform Coulomb-stress modeling. In all these applications, the underlying finite-source rupture models are treated as “data” (input information), but the uncertainties in these data (i.e. source models obtained from solving an inherently ill-posed inverse problem) are hardly known, and almost always neglected. The Source Inversion Validation (SIV) project attempts to better understand the intra-event variability of earthquake rupture models. We plan to build a long-standing and rigorous testing platform to examine the current state-of-the-art in earthquake source inversion that also facilitates to develop robust approaches to quantify rupture-model uncertainties. Our contribution reviews the current status of the SIV project, recent forward-modeling tests for point and extended sources in layered media, and discusses the strategy of the SIV-project for the coming years.

  4. Extended defects in 4H-silicon carbide homoepitaxial layers

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan

    The purpose of this thesis is to study the structure of extended defects in 4H-SIC homoepitaxial layers, and to identify their nucleation mechanisms. Characteristics of basal plane dislocations in 4H-SiC epilayers were investigated in a comprehensive manner, including their morphologies, Burgers' vectors, positions, and correlation with the extended defects propagating from the substrate. Plan-view transmission x-ray topography was the major characterization technique used in this study. Complementary data was obtained by KOH etching and optical microscopy. Trace of glide was detected on every basal plane dislocation in the entire 3-inch epilayer. In the center area of the epi-wafer, the glide can extend to macroscopic distance and form edge-type dislocations at the epilayer/surface interface. During the motion, dislocation half loop arrays were found to nucleate at the growth front. The magnitude of the resolved shear stress was estimated based on the radius of curvature of the dislocation lines. It surpassed the critical resolved shear stress at the epitaxial growth temperature. The stress was identified to be compressive in the epilayer. Its origin was studied. Nitrogen-doping-difference-induced misfit strain was excluded as the source of the stress. The structures of two morphological defects, 'carrots' and 'arrows', were studied. Cross-section x-ray topography was used to image the structure of carrot defect in whole. The defect was found to nucleate at the epilayer/substrate interface on a threading screw dislocation propagating from the substrate. Its structure was mainly composed of a prismatic stacking fault and a Frank-type basal plane stacking fault. The arrow defect was found to be produced by a spheroid shape inclusion in the volume of the epilayer. Zone axis diffraction pattern under transmission electron microscope identified the nature of the inclusion as 3C-SIC. It was determined to nucleate at the substrate surface contaminations.

  5. HDMI optical extender based on parallel optical transmitter and receiver

    NASA Astrophysics Data System (ADS)

    Luo, Zhixiang; Zhu, Zhishi; Zhang, Hailiang

    2009-08-01

    High-Definition Multimedia Interface(HDMI) can carry high quality multi-channel audio data and can carry all standard and highdefinition video formats. To send the information form video source to the display unit, the HDMI cable which carries four differential pairs is used. Now HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, so the traditional copper wire cable imposes limits on signal transmission distance and signal quality at so high speed. Optical fiber is of low dispersion, which in turn has the strength of longer signal transmission distance and better signal transmission quality in comparison to the traditional copper wire cable. So the optical extender consisting of two modules - one transmitter and one receiver- is developed. The transmitter connects to a computer/DVD player etc. The receiver connects to a display. Between the two modules, four-core ribbon fibre is used to transmit the video and audio signals. HDMI needs four differential pairs, so we design the parallel optical transmitter based on VCSEL array and VCSEL driver chip HXT3404 from Gigoptix and the parallel optical receiver based on PIN array and transimpedance amplifier chip HXR3404. Each channel can reach 3.125Gbps, so the data speed of the optical extender is 12.5Gbps. The experiment shows that the optical extender can transfer the video and audio data to the display uint 100 meter away.

  6. Extended treatment of older cigarette smokers

    PubMed Central

    Hall, Sharon M.; Humfleet, Gary L.; Muñoz, Ricardo F.; Reus, Victor I.; Robbins, Julie A.; Prochaska, Judith J.

    2009-01-01

    Aims Tobacco dependence treatments achieve abstinence rates of 25–30% at 1 year. Low rates may reflect failure to conceptualize tobacco dependence as a chronic disorder. The aims of the present study were to determine the efficacy of extended cognitive behavioral and pharmacological interventions in smokers ≥ 50 years of age, and to determine if gender differences in efficacy existed. Design Open randomized clinical trial. Setting A free-standing, smoking treatment research clinic. Participants A total of 402 smokers of ≥ 10 cigarettes per day, all 50 years of age or older. Intervention Participants completed a 12-week treatment that included group counseling, nicotine replacement therapy (NRT) and bupropion. Participants, independent of smoking status, were then assigned randomly to follow-up conditions: (i) standard treatment (ST; no further treatment); (ii) extended NRT (E-NRT; 40 weeks of nicotine gum availability); (iii) extended cognitive behavioral therapy (E-CBT; 11 cognitive behavioral sessions over a 40-week period); or (iv) E-CBT plus E-NRT (E-combined; 11 cognitive behavioral sessions plus 40 weeks nicotine gum availability). Measurements Primary outcome variable was 7-day point prevalence cigarette abstinence verified biochemically at weeks 24, 52, 64 and 104. Findings The most clinically important findings were significant main effects for treatment condition, time and the treatment × time interaction. The E-CBT condition produced high cigarette abstinence rates that were maintained throughout the 2-year study period [(week 24 (58%), 52 (55%), 64 (55%) and 104 (55%)], and was significantly more effective than E-NRT and ST across that period. No other treatment condition was significantly different to ST. No effects for gender were found. Conclusions Extended cognitive behavioral treatments can produce high and stable cigarette abstinence rates for both men and women. NRT does not add to the efficacy of extended CBT, and may hamper its efficacy

  7. Dark energy and extended dark matter halos

    NASA Astrophysics Data System (ADS)

    Chernin, A. D.; Teerikorpi, P.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Byrd, G. G.

    2012-03-01

    The cosmological mean matter (dark and baryonic) density measured in the units of the critical density is Ωm = 0.27. Independently, the local mean density is estimated to be Ωloc = 0.08-0.23 from recent data on galaxy groups at redshifts up to z = 0.01-0.03 (as published by Crook et al. 2007, ApJ, 655, 790 and Makarov & Karachentsev 2011, MNRAS, 412, 2498). If the lower values of Ωloc are reliable, as Makarov & Karachentsev and some other observers prefer, does this mean that the Local Universe of 100-300 Mpc across is an underdensity in the cosmic matter distribution? Or could it nevertheless be representative of the mean cosmic density or even be an overdensity due to the Local Supercluster therein. We focus on dark matter halos of groups of galaxies and check how much dark mass the invisible outer layers of the halos are able to host. The outer layers are usually devoid of bright galaxies and cannot be seen at large distances. The key factor which bounds the size of an isolated halo is the local antigravity produced by the omnipresent background of dark energy. A gravitationally bound halo does not extend beyond the zero-gravity surface where the gravity of matter and the antigravity of dark energy balance, thus defining a natural upper size of a system. We use our theory of local dynamical effects of dark energy to estimate the maximal sizes and masses of the extended dark halos. Using data from three recent catalogs of galaxy groups, we show that the calculated mass bounds conform with the assumption that a significant amount of dark matter is located in the invisible outer parts of the extended halos, sufficient to fill the gap between the observed and expected local matter density. Nearby groups of galaxies and the Virgo cluster have dark halos which seem to extend up to their zero-gravity surfaces. If the extended halo is a common feature of gravitationally bound systems on scales of galaxy groups and clusters, the Local Universe could be typical or even

  8. Extinctions and Distances to Dark Clouds from 2MASS, MegaCam and IPHAS Surveys: LDN 1525 in the Direction of the Aur OB1 Association

    NASA Astrophysics Data System (ADS)

    Straižys, V.; Drew, J. E.; Laugalys, V.

    The possibility of applying photometry from the 2MASS J, H, Ks, MegaCam u, g and IPHAS r, i, Hα surveys for determining the distance to the dark cloud LDN 1525 (TGU 1192) in the direction of the Aur OB1 association is investigated using the red clump giants. The main dust cloud, probably related to the emission nebulae Sh 2-232, Sh 2-233, Sh 2-235, the molecular cloud and the association Aur OB2, is found to be located at a distance of 1.3 kpc from the Sun. The nebula Sh 2-231 can be an object of the Perseus arm. The maximum extinction AV found in the cloud is close to 6 mag.

  9. Open-Source GIS

    SciTech Connect

    Vatsavai, Raju; Burk, Thomas E; Lime, Steve

    2012-01-01

    The components making up an Open Source GIS are explained in this chapter. A map server (Sect. 30.1) can broadly be defined as a software platform for dynamically generating spatially referenced digital map products. The University of Minnesota MapServer (UMN Map Server) is one such system. Its basic features are visualization, overlay, and query. Section 30.2 names and explains many of the geospatial open source libraries, such as GDAL and OGR. The other libraries are FDO, JTS, GEOS, JCS, MetaCRS, and GPSBabel. The application examples include derived GIS-software and data format conversions. Quantum GIS, its origin and its applications explained in detail in Sect. 30.3. The features include a rich GUI, attribute tables, vector symbols, labeling, editing functions, projections, georeferencing, GPS support, analysis, and Web Map Server functionality. Future developments will address mobile applications, 3-D, and multithreading. The origins of PostgreSQL are outlined and PostGIS discussed in detail in Sect. 30.4. It extends PostgreSQL by implementing the Simple Feature standard. Section 30.5 details the most important open source licenses such as the GPL, the LGPL, the MIT License, and the BSD License, as well as the role of the Creative Commons.

  10. ION SOURCE

    DOEpatents

    Blue, C.W.; Luce, J.S.

    1960-07-19

    An ion source is described and comprises an arc discharge parallel to the direction of and inside of a magnetic field. an accelerating electrode surrounding substantially all of the discharge except for ion exit apertures, and means for establishing an electric field between that electrode and the arc discharge. the electric field being oriented at an acute angle to the magnetic field. Ions are drawn through the exit apertures in the accelrating electrcde in a direction substantially divergent to the direction of the magnetic field and so will travel in a spiral orbit along the magnetic field such that the ions will not strike the source at any point in their orbit within the magnetic field.

  11. ION SOURCE

    DOEpatents

    Brobeck, W.M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from thc source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a varuum lock arrangement in conjunction with an arm for manipulating the bottle.

  12. ION SOURCE

    DOEpatents

    Bell, W.A. Jr.; Love, L.O.; Prater, W.K.

    1958-01-28

    An ion source is presented capable of producing ions of elements which vaporize only at exceedingly high temperatures, i.e.,--1500 degrees to 3000 deg C. The ion source utilizes beams of electrons focused into a first chamber housing the material to be ionized to heat the material and thereby cause it to vaporize. An adjacent second chamber receives the vaporized material through an interconnecting passage, and ionization of the vaporized material occurs in this chamber. The ionization action is produced by an arc discharge sustained between a second clectron emitting filament and the walls of the chamber which are at different potentials. The resultant ionized material egresses from a passageway in the second chamber. Using this device, materials which in the past could not be processed in mass spectometers may be satisfactorily ionized for such applications.

  13. Ion source

    DOEpatents

    Brobeck, W. M.

    1959-04-14

    This patent deals with calutrons and more particularly to an arrangement therein whereby charged bottles in a calutron source unit may be replaced without admitting atmospheric air to the calutron vacuum chamber. As described, an ion unit is disposed within a vacuum tank and has a reservoir open toward a wall of the tank. A spike projects from the source into the reservoir. When a charge bottle is placed in the reservoir, the spike breaks a frangible seal on the bottle. After the contents of the bottle are expended the bottle may be withdrawn and replaced with another charge bottle by a vacuum lock arrangement in conjunction with an arm for manipulating the bottle.

  14. Early Results from VLT SPHERE: Long-slit Spectroscopy of 2MASS 0122-2439 B, a Young Companion Near the Deuterium Burning Limit

    NASA Astrophysics Data System (ADS)

    Hinkley, Sasha; Bowler, Brendan P.; Vigan, Arthur; Aller, Kimberly M.; Liu, Michael C.; Mawet, Dimitri; Matthews, Elisabeth; Wahhaj, Zahed; Kraus, Stefan; Baraffe, Isabelle; Chabrier, Gilles

    2015-05-01

    We present 0.95-1.80 μm spectroscopy of the ˜12-27 MJup companion orbiting the faint (R ˜ 13.6), young (˜120 Myr) M-dwarf 2MASS J01225093-2439505 (“2M0122-2439 B”) at 1.″ 5 separation (50 AU). Our coronagraphic long-slit spectroscopy was obtained with the new high contrast imaging platform Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) during Science Verification. The unique long-slit capability of SPHERE enables spectral resolution an order of magnitude higher than other extreme AO exoplanet imaging instruments. With a low mass, cool temperature, and very red colors, 2M0122-2439 B occupies a particularly important region of the substellar color-magnitude diagram by bridging the warm directly imaged hot planets with late-M/early-L spectral types (e.g., β Pic b and ROXs 42Bb) and the cooler, dusty objects near the L/T transition (HR 8799bcde and 2MASS 1207b). We fit BT-Settl atmospheric models to our R ≈ 350 spectrum and find {{T}eff} = 1600 ± 100 K and log (g) = 4.5 ± 0.5 dex. Visual analysis of our 2M0122-2439 B spectrum suggests a spectral type L3-L4, and we resolve shallow J-band alkali lines, confirming its low gravity and youth. Specifically, we use the Allers & Liu spectral indices to quantitatively measure the strength of the FeH, VO, KI, spectral features, as well as the overall H-band shape. Using these indices, along with the visual spectral type analysis, we classify 2M0122-2439 B as an intermediate gravity object with spectral type L3.7 ± 1.0. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory Under Program ID 060.A-9381.

  15. Search for extended gamma ray emission in Markarian 421 using VERITAS observations

    NASA Astrophysics Data System (ADS)

    Fernandez Alonso, M.; VERITAS Collaboration

    Very high energy (VHE: 100 GeV) gamma rays coming from AGN can pair-produce on the intergalactic background light generating an electromagnetic cascade. If the Intergalactic Magnetic Field (IGMF) is sufficiently strong; this cascade may result in an extended isotropic emission of photons around the source; or halo. Using VERITAS observations of the blazar Markarian 421; we search for extended emission by comparing the source angular distribution () from a quiescent period with one coming from a flare period; which can be considered as ``halo-free". test showed no significant statistical differences between the samples; suggesting that the effect is either non-existent or too weak to be detected. We calculated upper limits for the extended flux considering different angle ranges; the most stringent being 8 of the Crab Nebulae flux (C.U); in the range .

  16. Generating code adapted for interlinking legacy scalar code and extended vector code

    DOEpatents

    Gschwind, Michael K

    2013-06-04

    Mechanisms for intermixing code are provided. Source code is received for compilation using an extended Application Binary Interface (ABI) that extends a legacy ABI and uses a different register configuration than the legacy ABI. First compiled code is generated based on the source code, the first compiled code comprising code for accommodating the difference in register configurations used by the extended ABI and the legacy ABI. The first compiled code and second compiled code are intermixed to generate intermixed code, the second compiled code being compiled code that uses the legacy ABI. The intermixed code comprises at least one call instruction that is one of a call from the first compiled code to the second compiled code or a call from the second compiled code to the first compiled code. The code for accommodating the difference in register configurations is associated with the at least one call instruction.

  17. The Extended X-ray Nebula of PSR J1420-6048

    SciTech Connect

    Van Etten, Adam; Romani, Roger W.; /Stanford U., Phys. Dept.

    2011-08-19

    The vicinity of the unidentified EGRET source 3EG J1420-6038 has undergone extensive study in the search for counterparts, revealing the energetic young pulsar PSR J1420-6048 and its surrounding wind nebula as a likely candidate for at least part of the emission from this bright and extended gamma-ray source. We report on new Suzaku observations of PSR J1420-6048, along with analysis of archival XMM Newton data. The low background of Suzaku permits mapping of the extended X-ray nebula, indicating a tail stretching {approx} 8 minutes north of the pulsar. The X-ray data, along with archival radio and VHE data, hint at a pulsar birthsite to the North, and yield insights into its evolution and the properties of the ambient medium. We further explore such properties by modeling the spectral energy distribution (SED) of the extended nebula.

  18. Carbon-14 time scale extended: comparison of chronologies.

    PubMed

    Grootes, P M

    1978-04-01

    Thermal diffusion isotopic enrichment of carbon-14 has extended the radiocarbon dating range to about 75,000 years ago. Twenty-eight samples obtained up to June 1976, mainly from northwest Europe, were dated. Consideration of the basic assumptions of carbon-14 dating and of the sources of contamination indicates that the ages are generally reliable. Together with the pollen analytic and stratigraphic the dates yield a more detailed radiocarbon time scale for climatic variations in northwest Europe, showing three early glacial interstades. The radiocarbon time scale agrees with the Camp Century chronology and with the thorium-230 ages of corals representing high sea level stands on New Guinea. Ther is a discrepancy between the radiocarbon time scale and the deep-sea chronology, which may be due to correlation errors. With a modified interpretation of the correlation, all four time scales agree within the estimated experimental uncertainties of the dating techniques used.

  19. Extended Operation of Stirling Convertors at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore

    2011-01-01

    Glenn Research Center (GRC) is supporting life and reliability database for free-piston Stirilng conversion via extended convertor operation Ongoing convertor operation: 18 convertors (4 TDCs from Infinia, 14 ASCs from Sunpower). 350,000 total convertor hours of operation. 218,000 on Infinia units and 132,000 on Sunpower units. Demonstrating steady convertor performance requires precise maintenance of operating conditions. Sources of disruption : Investigative tests: Varying operating frequency, hot-end temp, cold-end temp. Hot end control method: Constant heat input mode requires more user-adjustment than constant temperature mode. Long-term transients in hot end insulation were observed. Support facility: Open-bath circulator fluid concentration drifting. Nuisance shutdowns (instrumentation failure, EMI, power outages). Ambient temperature fluctuations due to room HVAC.

  20. Bayesian Population Forecasting: Extending the Lee-Carter Method.

    PubMed

    Wiśniowski, Arkadiusz; Smith, Peter W F; Bijak, Jakub; Raymer, James; Forster, Jonathan J

    2015-06-01

    In this article, we develop a fully integrated and dynamic Bayesian approach to forecast populations by age and sex. The approach embeds the Lee-Carter type models for forecasting the age patterns, with associated measures of uncertainty, of fertility, mortality, immigration, and emigration within a cohort projection model. The methodology may be adapted to handle different data types and sources of information. To illustrate, we analyze time series data for the United Kingdom and forecast the components of population change to the year 2024. We also compare the results obtained from different forecast models for age-specific fertility, mortality, and migration. In doing so, we demonstrate the flexibility and advantages of adopting the Bayesian approach for population forecasting and highlight areas where this work could be extended.

  1. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan

    PubMed Central

    Scialò, Filippo; Sriram, Ashwin; Fernández-Ayala, Daniel; Gubina, Nina; Lõhmus, Madis; Nelson, Glyn; Logan, Angela; Cooper, Helen M.; Navas, Plácido; Enríquez, Jose Antonio; Murphy, Michael P.; Sanz, Alberto

    2016-01-01

    Summary Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging. PMID:27076081

  2. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan.

    PubMed

    Scialò, Filippo; Sriram, Ashwin; Fernández-Ayala, Daniel; Gubina, Nina; Lõhmus, Madis; Nelson, Glyn; Logan, Angela; Cooper, Helen M; Navas, Plácido; Enríquez, Jose Antonio; Murphy, Michael P; Sanz, Alberto

    2016-04-12

    Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging.

  3. Bayesian Population Forecasting: Extending the Lee-Carter Method.

    PubMed

    Wiśniowski, Arkadiusz; Smith, Peter W F; Bijak, Jakub; Raymer, James; Forster, Jonathan J

    2015-06-01

    In this article, we develop a fully integrated and dynamic Bayesian approach to forecast populations by age and sex. The approach embeds the Lee-Carter type models for forecasting the age patterns, with associated measures of uncertainty, of fertility, mortality, immigration, and emigration within a cohort projection model. The methodology may be adapted to handle different data types and sources of information. To illustrate, we analyze time series data for the United Kingdom and forecast the components of population change to the year 2024. We also compare the results obtained from different forecast models for age-specific fertility, mortality, and migration. In doing so, we demonstrate the flexibility and advantages of adopting the Bayesian approach for population forecasting and highlight areas where this work could be extended. PMID:25962866

  4. Extending SemRep to the Public Health Domain

    PubMed Central

    Rosemblat, Graciela; Resnick, Melissa P.; Auston, Ione; Shin, Dongwook; Sneiderman, Charles; Fizsman, Marcelo; Rindflesch, Thomas C.

    2014-01-01

    We describe the use of a domain-independent methodology to extend a natural language processing (NLP) application, SemRep (Rindflesch, Fiszman, & Libbus, 2005), based on the knowledge sources afforded by the Unified Medical Language System (UMLS®) (Humphreys, Lindberg, Schoolman, & Barnett, 1998) to support the area of health promotion within the public health domain. Public health professionals require good information about successful health promotion policies and programs that might be considered for application within their own communities. Our effort seeks to improve access to relevant information for the public health profession, to help those in the field remain an information-savvy workforce. NLP and semantic techniques hold promise to help public health professionals navigate the growing ocean of information by organizing and structuring this knowledge into a focused public health framework paired with a user-friendly visualization application as a way to summarize results of PubMed searches in this field of knowledge. PMID:24729747

  5. Flexible Mx specification of various extended twin kinship designs.

    PubMed

    Maes, Hermine H; Neale, Michael C; Medland, Sarah E; Keller, Matthew C; Martin, Nicholas G; Heath, Andrew C; Eaves, Lindon J

    2009-02-01

    The extended twin kinship design allows the simultaneous testing of additive and nonadditive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission (Eaves et al., 1999). It also handles the contribution of these sources of variance to the (co)variation of multiple phenotypes. Keller et al. (2008) extended this comprehensive model for family resemblance to allow or a flexible specification of assortment and vertical transmission. As such, it provides a general framework which can easily be reduced to fit subsets of data such as twin-parent data, children-of-twins data, etc. A flexible Mx specification of this model that allows handling of these various designs is presented in detail and applied to data from the Virginia 30,000. Data on height, body mass index, smoking status, church attendance, and political affiliation were obtained from twins and their families. Results indicate that biases in the estimation of variance components depend both on the types of relative available for analysis, and on the underlying genetic and environmental architecture of the phenotype of interest.

  6. Alert Confidence Fusion in Intrusion Detection Systems with Extended Dempster- Shafer Theory

    SciTech Connect

    Yu, Dong; Frincke, Deborah A.

    2005-03-01

    Extend Dempster-Shafer Theory of Evidence to include differential weightings of alerts drawn from multiple sources. The intent is to support automated (and manual) response to threat by producing more realistic confidence ratings for IDS alerts than is currently available.

  7. Tikal obsidian: sources and typology

    SciTech Connect

    Moholy-Nagy, H.; Asaro, F.; Stross, F.H.

    1984-01-01

    The obsidian industry of Classic period Tikal, Guatemala, is discussed with regard to geological source determinations and behavioral typology. The potential of these two approaches for cultural reconstruction is greatly extended when they can supplement each other. Recent source determinations of obsidian artifacts from Tikal indicate (1) a behavioral link between locally-produced prismatic blades of Highland Guatemalan stone and ceremonial incised obsidians and eccentrics, and (2) a Central Mexican origin for a seemingly large portion of Tikal's obsidian projectile points and knives. 25 references, 3 figures, 5 tables.

  8. Extended Heat Deposition in Hot Jupiters: Application to Ohmic Heating

    NASA Astrophysics Data System (ADS)

    Ginzburg, Sivan; Sari, Re'em

    2016-03-01

    The observed radii of many giant exoplanets in close orbits exceed theoretical predictions. One suggested origin for this discrepancy is heat deposited deep inside the atmospheres of these “hot Jupiters”. Here, we study extended power sources that distribute heat from the photosphere to the deep interior of the planet. Our analytical treatment is a generalization of a previous analysis of localized “point sources”. We model the deposition profile as a power law in the optical depth and find that planetary cooling and contraction halt when the internal luminosity (i.e., cooling rate) of the planet drops below the heat deposited in the planet’s convective region. A slowdown in the evolutionary cooling prior to equilibrium is possible only for sources that do not extend to the planet’s center. We estimate the ohmic dissipation resulting from the interaction between the atmospheric winds and the planet’s magnetic field, and apply our analytical model to ohmically heated planets. Our model can account for the observed radii of most inflated planets, which have equilibrium temperatures of ≈1500-2500 K and are inflated to a radius of ≈ 1.6{R}J. However, some extremely inflated planets remain unexplained by our model. We also argue that ohmically inflated planets have already reached their equilibrium phase, and no longer contract. Following Wu & Lithwick, who argued that ohmic heating could only suspend and not reverse contraction, we calculate the time it takes ohmic heating to re-inflate a cold planet to its equilibrium configuration. We find that while it is possible to re-inflate a cold planet, the re-inflation timescales are longer by a factor of ≈ 30 than the cooling time.

  9. SOURCE EXPLORER: Towards Web Browser Based Tools for Astronomical Source Visualization and Analysis

    NASA Astrophysics Data System (ADS)

    Young, M. D.; Hayashi, S.; Gopu, A.

    2014-05-01

    As a new generation of large format, high-resolution imagers come online (ODI, DECAM, LSST, etc.) we are faced with the daunting prospect of astronomical images containing upwards of hundreds of thousands of identifiable sources. Visualizing and interacting with such large datasets using traditional astronomical tools appears to be unfeasible, and a new approach is required. We present here a method for the display and analysis of arbitrarily large source datasets using dynamically scaling levels of detail, enabling scientists to rapidly move from large-scale spatial overviews down to the level of individual sources and everything in-between. Based on the recognized standards of HTML5+JavaScript, we enable observers and archival users to interact with their images and sources from any modern computer without having to install specialized software. We demonstrate the ability to produce large-scale source lists from the images themselves, as well as overlaying data from publicly available source ( 2MASS, GALEX, SDSS, etc.) or user provided source lists. A high-availability cluster of computational nodes allows us to produce these source maps on demand and customized based on user input. User-generated source lists and maps are persistent across sessions and are available for further plotting, analysis, refinement, and culling.

  10. Extended space charge in concentration polarization.

    PubMed

    Rubinstein, Isaak; Zaltzman, Boris

    2010-09-15

    This paper is concerned with ionic currents from an electrolyte solution into a charge-selective solid, such as, an electrode, an ion-exchange membrane or an array of nano-channels in a micro-fluidic system, and the related viscous fluid flows on the length scales varying from nanometers to millimeters. All systems of this kind have characteristic voltage-current curves with segments in which current nearly saturates at some plateau values due to concentration polarization--formation of solute concentration gradients under the passage of a DC current. A number of seemingly different phenomena occurring in that range, such as anomalous rectification in cathodic copper deposition from a copper sulfate solution, super-fast vortexes near an ion-exchange granule, overlimiting conductance in electrodialysis and the recently observed non-equilibrium electroosmotic instability, result from the formation of an additional extended space charge layer next to that of a classical electrical double layer at the solid/liquid interface. In this paper we review the peculiar features of the non-equilibrium electric double layer and extended space charge and the possibility of their direct probing by harmonic voltage/current perturbations through a linear and non-linear system's response, by the methods of electrical impedance spectroscopy and via the anomalous rectification effect. On the relevant microscopic scales the ionic transport in the direction normal to the interface is dominated by drift-diffusion; hence, the extended space charge related viscous flows remain beyond the scope of this paper. PMID:20619824

  11. Fixed provisional restorations for extended prosthodontic treatment.

    PubMed

    Amet, E M; Phinney, T L

    1995-01-01

    During extensive and extended prosthodontic treatment, there is need for a durable esthetic fixed provisional restoration that can be easily modified as treatment is completed and that is cost-effective. The needed strength of provisional restorations can be underestimated, and the management of complex treatment is then more difficult and the prosthetic results less predictable. Knowledge of the criteria for treatment restorations and the adequacies of their construction is essential for the prevention of catastrophic failures, patient management problems, and compromised results. Many times in complex prosthodontic treatment, changes are needed in esthetics, the plane of occlusion, incisal edge position, lip support, and type of occlusion, or the soft and/or hard tissues need to be altered or grafted surgically. In addition, after first- and second-stage implant surgery and extractions, there is a need for immediate tooth replacement with extended time between prosthodontic treatments. These prosthodontic changes and challenges can be addressed with reinforced acrylic provisional restorations that are adequately cemented and retained during the interim stage of healing and treatment. In addition, the provisional restoration should serve as a guide for the final restoration while esthetics and phonetics are evaluated for patient acceptance. This article describes the materials used with an indirect technique for fabrication of an extended-treatment acrylic provisional restoration that uses an internal cast metal support system for strength. This support system consists of metal bands or copings with extensions into edentulous areas and that have been opaqued to neutralize the metallic color. A matrix of vinyl polysiloxane made from the diagnostic wax-up simplifies construction of the acrylic, resulting in a strong, ridged, yet esthetic result.

  12. Implementing extended observing at the JCMT

    NASA Astrophysics Data System (ADS)

    Walther, Craig; Dempsey, Jessica; Campbell, Ian

    2014-08-01

    The James Clerk Maxwell Telescope (JCMT) is the largest single dish submillimetre telescope in the world. Recently the Joint Astronomy Centre (JAC) has learned that the JCMT will no longer receive financial support from its original supporting agencies after September 2014. There is significant pressure to complete some surveys that have been in progress at the JCMT for many years now. With the goal of completing a higher percentage of these surveys it was decided to take advantage of the hours between when the telescope operator leaves the telescope and when the day crew arrives. These hours generally have reasonable seeing and low column integrated water vapor, so they are good for observing. This observing is being performed remotely, in Hilo, without staff at the telescope, by staff members who do not have telescope operation as part of their job descriptions. This paper describes the hardware changes necessary to implement remote observing at JCMT. It also describes the software needed for remote, fail safe, operation of the telescope. The protocols and rules for passing the control of the telescope between the various groups are discussed. Since these Extended Operators are not expert telescope operators, the system was simplified as much as possible, but some training was necessary and proper checklists are essential. Due to the success of the first phase of Extending Observing at the JCMT, the hours when the weather is good and no one is at the telescope, but no day crew is on the way, are also now being utilized. Extended Observing has already yielded a considerable amount of science observing time.

  13. Extending "color constancy" outside the visible region.

    PubMed

    Ratnasingam, Sivalogeswaran; Collins, Steve; Hernández-Andrés, Javier

    2011-04-01

    In this paper, the results of an investigation of the possibility of extending "color constancy" to obtain illuminant-invariant reflectance features from data in the near-ultraviolet (UV) and near-infrared (IR) wavelength regions are reported. These features are obtained by extending a blackbody-model-based color constancy algorithm proposed by Ratnasingam and Collins [J. Opt. Soc. Am. A27, 286 (2010)] to these additional wavelengths. Ratnasingam and Collins applied the model-based algorithm in the visible region to extract two illuminant-invariant features related to the wavelength-dependent reflectance of a surface from the responses of four sensors. In this paper, this model-based algorithm is extended to extract two illuminant-invariant reflectance features from the responses of sensors that cover the visible and either the near-UV or near-IR wavelength. In this investigation, test reflectance data sets are generated using the goodness-fitness coefficient (GFC). The appropriateness of the GFC for generating the test data sets is demonstrated by comparing the results obtained with these data with those obtained from data sets generated using the CIELab distance. Results based upon the GFC are then presented that suggest that the model-based algorithm can extract useful features from data from the visible and near-IR wavelengths. Finally, results are presented that show that, although the spectrum of daylight in the near UV is very different from a blackbody spectrum, the algorithm can be modified to extract useful features from visible and near-UV wavelengths. PMID:21478947

  14. Improving epidemic control strategies by extended detection

    NASA Astrophysics Data System (ADS)

    Karp, Paweł; Dybiec, Bartłomiej; Kleczkowski, Adam

    2014-11-01

    Majority of epidemics eradication programs work in preventive responsive way. The lack of exact information about epidemiological status of individuals makes responsive actions less efficient. Here, we demonstrate that additional tests can significantly increase the efficiency of "blind" treatment (vaccination or culling). Eradication strategy consisting of "blind" treatment in very limited local neighborhood supplemented by extra tests in a little bit larger neighborhood is able to prevent invasion of even highly infectious diseases and to achieve this at a cost lower than for the "blind" strategy. The effectiveness of the extended strategy depends on such parameters as the test efficiency and test cost.

  15. Extended moment arm anti-spin device

    NASA Technical Reports Server (NTRS)

    Whipple, R. D. (Inventor)

    1985-01-01

    A device which corrects aerodynamic spin is provided in which a collapsible boom extends an aircraft moment arm and an anti-spin parachute force is exerted upon the end of the moment arm to correct intentional or inadvertent aerodynamic spin. This configuration effects spin recovery by means of a parachute whose required diameter decreases as an inverse function of the increasing length of the moment arm. The collapsible boom enables the parachute to avoid the aircraft wake without mechanical assistance, retracts to permit steep takeoff, and permits a parachute to correct spin while minimizing associated aerodynamic, structural and in-flight complications.

  16. Extending quantum coherence of superconducting flux

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Kamal, Archana; Orlando, Terry; Gustavsson, Simon; Oliver, William; Engineering Quantum Systems, MIT Team

    We present the design of a superconducting qubit with multiple Josephson junctions. The design starts with a capacitively shunted flux qubit, and it incorporates particular junction parameter choices for the purpose of simultaneously optimizing over transition frequency, anharmonicity, flux- and charge-noise sensitivity around flux degeneracy. By studying the scaling properties with design parameters, we identify directions to extend coherence substantially. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002.

  17. The extended SMAS approach to neck rejuvenation.

    PubMed

    Perkins, Stephen W; Waters, Heather H

    2014-05-01

    Jowling, submental lipoptosis, and platysmal banding can affect self-image and reduce quality of life, leading one to seek facial and neck rejuvenation. With realistic expectations, a facelift can provide the desired improvement in appearance and sense of well-being. Before any intervention, a detailed history, focused examination, communication of expected outcomes with the assistance of preoperative digital imaging, and discussion of perioperative instructions are of utmost importance. Although many techniques exist, the modified deep plane extended superficial muscular aponeurotic system rhytidectomy with submentoplasty reliably delivers a significant improvement with lasting results. PMID:24745387

  18. Praxair extending hydrogen pipeline in Southeast Texas

    SciTech Connect

    Not Available

    1992-08-24

    This paper reports that Praxair Inc., an independent corporation created by the spinoff of Union Carbide Corp.'s Linde division, is extending its high purity hydrogen pipeline system from Channelview, Tex., to Port Arthur, Tex. The 70 mile, 10 in. extension begins at a new pressure swing adsorption (PSA) purification unit next to Lyondell Petrochemical Co.'s Channelview plant. The PSA unit will upgrade hydrogen offgas from Lyondell's methanol plant to 99.99% purity hydrogen. The new line, advancing at a rate of about 1 mile/day, will reach its first customer, Star Enterprise's 250,000 b/d Port Arthur refinery, in September.

  19. Extended Scaling Relations for Planar Lattice Models

    NASA Astrophysics Data System (ADS)

    Benfatto, G.; Falco, P.; Mastropietro, V.

    2009-12-01

    It is widely believed that the critical properties of several planar lattice systems, like the Eight Vertex or the Ashkin-Teller models, are well described by an effective continuum fermionic theory obtained as a formal scaling limit. On the basis of this assumption several extended scaling relations among their indices were conjectured. We prove the validity of some of them, among which the ones predicted by Kadanoff (Phys Rev Lett 39:903-905, 1977) and by Luther and Peschel (Phys Rev B 12:3908-3917, 1975).

  20. Extending the applicability of multigrid methods

    SciTech Connect

    Brannick, J; Brezina, M; Falgout, R; Manteuffel, T; McCormick, S; Ruge, J; Sheehan, B; Xu, J; Zikatanov, L

    2006-09-25

    Multigrid methods are ideal for solving the increasingly large-scale problems that arise in numerical simulations of physical phenomena because of their potential for computational costs and memory requirements that scale linearly with the degrees of freedom. Unfortunately, they have been historically limited by their applicability to elliptic-type problems and the need for special handling in their implementation. In this paper, we present an overview of several recent theoretical and algorithmic advances made by the TOPS multigrid partners and their collaborators in extending applicability of multigrid methods. Specific examples that are presented include quantum chromodynamics, radiation transport, and electromagnetics.