15,541 research outputs found
Letter, William Ray to Jim Rodgers, Museum on the Mall (MOM) Exhibit, June 20, 1979
No full textA letter from William Ray to Jim Rodgers thanking him for volunteering to help with programs at the Museum on the Mall Exhibit.https://digitalcommons.usf.edu/audubon_coastal_islands_records/1105/thumbnail.jp
Rodgers, Randall W., D.O.
No full textA 1981 graduate of TCOM who opened his “country practice” on the outskirts of Tyler, he narrates the “ups and downs” he experienced during his first year in rural practice.
Interviewed by C. Ray Stokes, February 22, 198
[Letter from Alex Bradford to Lieutenant and Mrs. Ray Starner - November 4, 1940]
No full textLetter from Alex Bradford to Lieutenant and Mrs. Ray Starner describing the the current state of affairs that the author was experiencing, including: the London blitz, the moral of the troops on the ground, and the collective company of men opposing the Nazi regime
The student's guide to completing an author study
No full textThe 'Student's guide to completing an author study' emerged during the early development of the school library resource center program at Glen Stewart Elementary School in Stratford Canada on Prince Edward Island. This research process centered on an author study, with direct teaching and clear assignment. The resulting model has been adapted to various grade levels and subject areas in different schools.Source type: Electronic(1)http://proquest.umi.com/pqdweb?did=49237063&Fmt=7&clientId=65345&RQT=309&VName=PQ
Active X-ray optics for the next generation of X-ray space telescopes
No full textDescribed within is the design, manufacture, metrology and X-ray testing of an active X-ray
prototype intended for the next generation of X-ray telescopes. One of the challenges faced by
the X-ray telescope community is how to combine high resolution and high sensitivity into one
system, as weight limitations place constraints on the optics that can be launched. Therefore the
mandate of the active X-ray prototype is to provide high sensitivity through the ability of the optics
to be nested and to deliver high angular resolution through the active control of the optic’s form.
Piezoelectric unimorph actuators provide the active component: it is intended that they will correct
for figure errors within the optic and therefore increase the angular resolution capability.
The prototype’s design is based upon an ellipsoidal segment which provides point-to-point
focussing of an X-ray source. The prototype itself is composed of an electroformed nickel optic
where the non-reflective surface is populated with 30 piezoelectric actuators and it is the production
of the prototype that is the core of the presented research. Metrology of the actuators’ influence
functions is presented and highlight the prototype’s ability to deform its optic surface by microns.
In addition, the measured influence functions are compared against finite element models and a
distinct similarity between the functions is observed.
The prototype was tested at an X-ray beamline facility in November 2008 and the results
showed the prototype’s ability to correct the optic to achieve an improved angular resolution: from
0.786 arc-minutes to 0.686 arc-minutes in terms of full width half maximum. Finally, difficulties
in the manufacture of the prototype and X-ray testing shall be presented alongside future work in
conclusion to this thesis
Author, Geraldine Brooks at the National Library of Australia for the 2009 Ray Mathew Lecture, Canberra, 23 October 2009 [picture] /
No full textTitle from acquisitions documentation.; Part of the collection: Portraits of author, Geraldine Brooks during her visit to the National Library of Australia for the 2009 Ray Mathew Lecture, Canberra, 23 October 2009.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Photographed by a staff member of the National Library of Australia
The invisible artist: Arrangers in popular music (1950-2000): Their contribution and techniques
No full textThis thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.This thesis is based on the research conducted by the author for the series,
Richard Niles' History of Pop Arranging, seven thirty-minute documentary
programmes for BBC Radio 2, researched, written and presented by the author and
broadcast in 2003. It also draws on interviews conducted by the author (and other
research) between 2002 and 2007 both for the radio series and for this thesis and on
the author's experience as a professional arranger in popular music working with
many of the genre's significant recording artists including Paul McCartney, Ray
Charles, Cher, Tina Turner, Westlife, Tears For Fears, Dusty Springfield, James
Brown, Pet Shop Boys, Kylie Minogue and producers including Trevor Hom, Steve
Lipson, Steve Mac and Steve Anderson.
It will be argued that the role of the arranger in popular music has often been
undervalued and that during a critical period of popular music history (1950-2000)
arrangers played a significant part in the evolution of musical content. This thesis is,
to the best of the author's knowledge, the first time (apart from the above mentioned
documentary) the subject has ever been examined. The arranger is "invisible" because musical arrangers are often un-credited on
record liner notes or in books or articles concerning popular music. A considerable
amount of research has been necessary to determine who wrote many of the
arrangements considered herein. Motown's Berry Gordy purposely kept the names of
musicians and arrangers off the records because he feared others might 'poach' the
trademark 'Motown Sound'. Other record labels considered the job of the arranger to
be reminiscent of an earlier era, diluting the Rock 'n' Roll image of emotion and
spontanaeity they wished to promote. Some producers and recording artists disliked
sharing credit for their work. Motown arranger David Van dePitte told the author that
arranging was "thankless and anonymous - a very service-oriented profession where
others often take credit for what you've done." Arranging has therefore remained an
intrinsically unseen art created by 'invisible' artists. By analyzing many recordings,
revealing the techniques and concepts they have used in their work to create popular
records, arrangers and their art will be made more 'visible'
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
The effects of atmosphere conditions on gamma-ray astronomy
No full textThe High Energetic Stereoscopic System (H.E.S.S.) experiment is an array of imaging atmospheric Cherenkov (IAC) telescopes of the next generation, with enlarged mirrors and advanced detector electronics compared to its predecessors. As a member of the international H.E.S.S. collaboration, the Durham 7-rау astronomy group took over the responsibility for design, construction and commissioning of calibration systems for the H.E.S.S. telescopes and atmospheric monitoring devices. The atmosphere is an essential part of the detector system for the IAC technique, monitoring of the atmosphere's parameter is therefore important for energy calibration of the detector and variability studies of 7-ray sources to distinguish between detector and source fluctuations. A weather station, several infrared radiometers and an infrared LIDAR system have been installed to provide constant monitoring of all relevant parameters. This thesis reports about the work performed for the design and commissioning of the calibration module. Furthermore, the technicalities of the LIDAR system and the IR radiometer, their use in terms of 7-ray astronomy, especially studies about the variability of zenith angle dependencies and the correlation with other atmospheric parameters and telescope trigger rates are discussed
X-ray polarization in relativistic jets
No full textWe investigate the polarization properties of Comptonized X-rays from relativistic jets in active galactic nuclei (AGN) using Monte Carlo simulations. We consider three scenarios commonly proposed for the observed X-ray emission in AGN: Compton scattering of blackbody photons emitted from an accretion disc; scattering of cosmic microwave background (CMB) photons and self-Comptonization of intrinsically polarized synchrotron photons emitted by jet electrons. Our simulations show that for Comptonization of disc and CMB photons, the degree of polarization of the scattered photons increases with the viewing inclination angle with respect to the jet axis. In both cases, the maximum linear polarization is ≈20 per cent. In the case of synchrotron self-Comptonization (SSC), we find that the resulting X-ray polarization depends strongly on the seed synchrotron photon injection site, with typical fractional polarizations P≈ 10–20 per cent when synchrotron emission is localized near the jet base, while P≈ 20–70 per cent for the case of uniform emission throughout the jet. These results indicate that X-ray polarimetry may be capable of providing unique clues to identify the location of particle acceleration sites in relativistic jets. In particular, if synchrotron photons are emitted quasi-uniformly throughout a jet, then the observed degree of X-ray polarization may be sufficiently different for each of the competing X-ray emission mechanisms (synchrotron, SSC or external Comptonization) to determine which is the dominant process. However, X-ray polarimetry alone is unlikely to be able to distinguish between disc and CMB Comptonization
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