Now showing items 95-114 of 157

    • Performance analysis of cone detection algorithms 

      Mariotti, Letizia; Devaney, Nicholas (Optical Society of America, 2015-04-01)
      Many algorithms have been proposed to help clinicians evaluate cone density and spacing, as these may be related to the onset of retinal diseases. However, there has been no rigorous comparison of the performance of these ...
    • Performance review of multiple reference versus time domain optical coherence tomography 

      Neuhaus, Kai; McNamara, Paul M.; Alexandrov, Sergey; O'Gorman, Seán; Hogan, Josh; Wilson, Carol; Leahy, Martin J. (IEEE, 2018-04-19)
      We present a detailed characterization of noise sources in multiple reference optical coherence tomography (MR-OCT) compared to time-domain OCT (TD-OCT). The noise characteristics were modeled based on the TD-OCT noise ...
    • Phasing-out of legacy brominated flame retardants: The UNEP Stockholm Convention and other legislative action worldwide 

      Sharkey, Martin; Harrad, Stuart; Abou-Elwafa Abdallah, Mohamed; Drage, Daniel S.; Berresheim, Harald (Elsevier, 2020-08-18)
      Due to their toxicity and persistence, several families of brominated flame retardants (BFRs) have been listed as persistent organic pollutants (POPs) in the Stockholm Convention, a multilateral treaty overseen by the ...
    • Portable X-ray fluorescence for the detection of POP-BFRs in waste plastics 

      Sharkey, Martin; Abdallah, Mohamed Abou-Elwafa; Drage, Daniel S; Harrad, Stuart; Berresheim, Harald (Elsevier, 2018-05-26)
      The purpose of this study was to establish the efficacy of portable X-ray fluorescence (XRF) instrumentation as a screening tool for a variety of end of life plastics which may contain excess amounts of brominated flame ...
    • Pulse variation of the optical emission of Crab pulsar 

      Shearer, Andrew (2007)
      The stability of the optical pulse of the Crab pulsar is analyzed based on the 1 $\mu$s resolution observations with the Russian 6-meter and William Hershel telescopes equipped with different photon-counting detectors. The ...
    • Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy 

      Lang, Mark (2009)
      The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10^12 electron ...
    • Real-time quantitative visualization of 3D structural information 

      Alexandrov, Sergey; Uttam, Shikhar; Bista, Rajan K.; Zhao, Chengquan; Liu, Yang (Optica, 2012)
      We demonstrate a novel approach for the real time visualization and quantification of the 3D spatial frequencies in an image domain. Our approach is based on the spectral encoding of spatial frequency principle and permits ...
    • A recent change in the optical and gamma ray polarization of the Crab nebula and pulsar 

      Moran, Paul; Kyne, Gillian; Redfern, R. M.; Shearer, Andrew (Oxford journals, 2015-12-31)
      We report on observations of the polarization of optical and γ-ray photons from the Crab nebula and pulsar system using the Galway Astronomical Stokes Polarimeter (GASP), the Hubble Space Telescope, Advanced Camera for ...
    • Recent Results from the VERITAS Collaboration 

      Lang, Mark; Gillanders, Gary (2002)
      A decade after the discovery of TeV gamma-rays from the blazar Mrk 421 (Punch et al. 1992), the list of TeV blazars has increased to five BL Lac objects: Mrk 421 (Punch et al. 1992; Petry et al. 1996; Piron et al. 2001), ...
    • Refinement and validation of an exposure model for the pharmaceutical industry 

      Mc Donnell, Patricia E.; Coggins, Marie (2011)
      Objectives: Assessment of worker's exposure is becoming increasingly critical in the pharmaceutical industry as drugs of higher potency are being manufactured. The batch nature of operations often makes it difficult to ...
    • Residential ventilation and health 

      Coggins, Marie; Jones, Simon (Air Infiltration and Ventilation Centre (AIVC) and International Energy Agency (IEA), 2021-07)
      AIVC Technical Note 68 (TN 68) "Residential Ventilation and Health is one of the outcomes of the work performed under the framework of AIVC s project Ventilation & Health and benefited from contributions by several ...
    • Rotational Modulation of M/L Dwarfs due to Magnetic Spots 

      Butler, Ray (2007)
      We find periodic I-band variability in two ultracool dwarfs, TVLM 513-46546 and 2MASS J00361617+1821104, on either side of the M/L dwarf boundary. Both of these targets are short-period radio transients, with the detected ...
    • Sea-spray regulates sulfate cloud droplet activation over oceans 

      Fossum, Kirsten N.; Ovadnevaite, Jurgita; Ceburnis, Darius; Preißler, Jana; Snider, Jefferson R.; Huang, Ru-Jin; Zuend, Andreas; O’Dowd, Colin (Nature Research (part of Springer Nature), 2020-04-08)
      Sulfate aerosols are typically the dominant source of cloud condensation nuclei (CCN) over remote oceans and their abundance is thought to be the dominating factor in determining oceanic cloud brightness. Their activation ...
    • A search for brief optical flashes associated with the SETI target KIC 8462852 

      Gillanders, Gary; Lang, Mark (IOP Publishing, 2016-02-18)
      The F-type star KIC. 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used ...
    • A search for CO+ in planetary nebulae 

      Redman, Matt P. (2007)
      We have carried out a systematic search for the molecular ion CO+ in a sample of 8 protoplanetary and planetary nebulae in order to determine the origin of the unexpectedly strong HCO+ emission previously detected in these ...
    • A Search for Dark Matter Annihilation with the Whipple 10m Telescope 

      Lang, Mark (2008)
      We present observations of the dwarf galaxies Draco and Ursa Minor, the local group galaxies M32 and M33, and the globular cluster M15 conducted with the Whipple 10m gamma-ray telescope to search for the gamma-ray signature ...
    • A search for optical bursts from RRAT J1819-1458: II. Simultaneous ULTRACAM-Lovell Telescope observations 

      Shearer, Andrew (2011)
      The Rotating RAdio Transient (RRAT) J1819-1458 exhibits ~3 ms bursts in the radio every ~3 min, implying that it is visible for only ~1 per day. Assuming that the optical light behaves in a similar manner, long exposures ...
    • A search for pulsations from Geminga above 100 GeV with VERITAS 

      Connolly, M.P.; Gillanders, Gary; Moriarty, P.; Lang, Mark (American Astronomical Society, 2015-02-10)
      We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were ...
    • A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar 

      Lang, Mark; Gillanders, Gary (1999)
      We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 ...
    • A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar 

      Lang, Mark; Gillanders, Gary; Burdett, A. M.; Bond, I. H.; Boyle, P. J.; Bradbury, S. M.; Buckley, J. H.; Carter-Lewis, D. A.; Catanese, M.; Cawley, M. F.; D'Vali, M.; Fegan, D. J.; Fegan, S. J.; Finley, J. P.; Gaidos, J. A.; Gillanders, G. H.; Hall, T. A.; Hillas, A. M.; Kildea, J.; Knapp, J.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Lessard, R. W.; Masterson, C.; Moriarty, P.; Quinn, J.; Rose, H. J.; Samuelson, F. W.; Sembroski, G. H.; Srinivasan, R.; Vassiliev, V. V.; Weekes, T. C. (1999)
      We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory's 10m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 ...