Now showing items 64-83 of 127

    • Nano-sensitive optical coherence tomography 

      Alexandrov, Sergey; Subhash, Hrebesh M.; Zam, Azhar; Leahy, Martin (Royal Society of Chemistry, 2014)
      Depth resolved label-free detection of structural changes with nanoscale sensitivity is an outstanding problem in the biological and physical sciences and has significant applications in both the fundamental research and ...
    • Nanosensitive optical coherence tomography for the study of changes in static and dynamic structures 

      Subhash, Hrebesh M.; Leahy, Martin; Alexandrov, Sergey (IOP Science, 2014-03-06)
      We briefly discuss the principle of image formation in Fourier domain optical coherence tomography (OCT). The theory of a new approach to improve dramatically the sensitivity of conventional OCT is described. The approach ...
    • Novel approach for label free super-resolution imaging in far field 

      Alexandrov, Sergey; McGrath, James; Hrebesh, Subhash; Leahy, Martin (Nature Publishing Group, 2015)
      Progress in the emerging areas of science and technology, such as bio- and nano-technologies, depends on development of corresponding techniques for imaging and probing the structures with high resolution. Recently, the ...
    • Observation of Extended VHE Emission from the Supernova Remnant IC 443 with VERITAS 

      Lang, Mark; Gillanders, Gary (2009)
      We present evidence that the very-high-energy (VHE, E > 100 GeV) gamma-ray emission coincident with the supernova remnant IC 443 is extended. IC 443 contains one of the best-studied sites of supernova remnant/molecular ...
    • Observation of gamma-ray emission from the galaxy M87 above 250 GeV with VERITAS 

      Lang, Mark; Gillanders, Gary (2008)
      The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in Active Galactic Nuclei from radio waves to TeV gamma-rays. Here we report the detection ...
    • Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS 

      Lang, Mark; Gillanders, Gary (2010)
      We report on observations of very high-energy gamma rays from the shell-type supernova remnant Cassiopeia A with the VERITAS stereoscopic array of four imaging atmospheric Cherenkov telescopes in Arizona. The total exposure ...
    • Observations of the Unidentified TeV Gamma-Ray Source TeV J2032+4130 with the Whipple Observatory 10 m Telescope 

      Lang, Mark; Gillanders, Gary (2006)
      We report on observations of the sky region around the unidentified TeV gamma-ray source TeV J2032+4130 carried out with the Whipple Observatory 10 m atmospheric Cherenkov telescope for a total of 65.5 hrs between 2003 and ...
    • Occupational exposures in an equestrian centre to respirable dust and respirable crystalline silica 

      Bulfin, Kathleen; Cowie, Hilary; Galea, Karen S.; Connolly, Alison; Coggins, Marie Ann (MDPI, 2019-09-03)
      Abstract: Sand-based products are regularly used as footing material on indoor equestrian arenas, creating a potential occupational exposure risk for respirable crystalline silica (RCS) for equestrian workers training and ...
    • Optical Observations of PSR J0205+6449 

      Shearer, Andrew (2008)
      PSR J0205+6449 is a X-ray and radio pulsar in supernova remnant 3C 58. We report on observations of the central region of 3C 58 using the 4.2-m William Herschel Telescope with the intention of identifying the optical ...
    • Optical pulsations from the anomalous X-ray pulsar 1E 1048.1-5937 

      Shearer, Andrew (2009)
      We present high-speed optical photometry of the anomalous X-ray pulsar 1E 1048.1-5937 obtained with ULTRACAM on the 8.2-m Very Large Telescope in June 2007. We detect 1E 1048.1-5937 at a magnitude of i'=25.3+/-0.2, consistent ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...