6,996 research outputs found
Volatility post Black Monday, myth or reality?
No full textPopular opinion argues that since the crash of 1987 markets worldwide have become increasingly volatile. Steve Thomas and Ray O'Brien approach the topic using different empirical data, with surprising results
RoMEO Studies 6: Rights metadata for open-archiving
No full textThis is the final study in a series of six emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open-archiving) which investigated the Intellectual Property Rights (IPR) issues relating to academic author self-archiving of research papers. It reports the results of a survey of 542 academic authors showing the level of protection required for their open-access research papers. It then describes the selection of an appropriate means of expressing those rights through metadata and the resulting choice of Creative Commons licences. Finally it outlines proposals for communicating rights metadata via the Open Archives Initiative’s Protocol for Metadata Harvesting (OAI-PMH)
Other title: Trial brief of intervenor plaintiffs Senator Jeff King, Senator Steve Abrams and Senator Ray Merrick.
No full textThis document is part of a collection of publications provided for information on Redistricting in Kansas.; application/pdf"Come Now Plaintiff Intervenors Senator Jeff King, Senator Steve Abrams, and Senator Ray Merrick, by and through counsel of record, and state that the senatorial map For the People 13(b) best satisfies federal and state constitutional, statutory requisites and guidelines issued by the Kansas legislature for senatorial redistricting.
Interactive ray shading of FRep objects
No full textIn this paper we present a method for interactive rendering general procedurally defined functionally represented (FRep) objects using the acceleration with graphics hardware, namely Graphics Processing Units (GPU). We obtain interactive rates by using GPU acceleration for all computations in rendering algorithm, such as ray-surface intersection, function evaluation and normal computations. We compute primary rays as well as secondary rays for shadows, reflection and refraction for obtaining high quality of the output visualization and further extension to ray-tracing of FRep objects. The algorithm is well-suited for modern GPUs and provides acceptable interactive rates with good quality of the results. A wide range of objects can be rendered including traditional skeletal implicit surfaces, constructive solids, and purely procedural objects such as 3D fractals
Steve Stockman, Workshop
No full textSteve Stockman is the author of Walk On: The Spiritual Journey of U2. He is also a pop culture critic and weekly radio host on BBC Radio Ulster. Stockman is the Presbyterian Chaplain of Queens University in Belfast, Ireland
RoMEO Studies 5: IPR issues for OAI Data and Service Providers
No full textThis paper is the fifth in a series of studies emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open-archiving). It reports the results of two surveys of OAI Data Providers (DPs) and Service Providers (SPs) with regards to the rights issues they face. It finds that very few DPs have rights agreements with depositing authors and that there is no standard approach to the creation of rights metadata. The paper considers the rights protection afforded individual and collections of metadata records under UK Law and contrasts this with DP and SP’s views on the rights status of metadata and how they wish to protect it. The majority of DP and SPs believe that a standard way of describing both the rights status of documents and of metadata would be usefu
Magnetic X-ray Reflectivity
No full textThe scope of the thesis is to demonstrate the feasibility to examine magnetization profiles of
thin films and multilayer systems via magnetic soft and hard x-ray reflectivity. The focus here
is on 3d transition metals, which are used mainly for development of numerous noval magnetic
devices, that are both technologically and scientifically interesting. Complementary to Neutron
diffraction, which is the standard tool for the examination of magnetic structures in matter,
magnetic x-ray diffraction permits to study small samples and exhibits better Qz-resolution due
its small and only slightly divergent beam. The biggest advantage is its element specificity,
which enables one to probe different magnetic sites separately. The method of magnetic x-ray
reflectivity combines the strong magnetic circular dichroism (MCD) effect, significantly
enhancing the magnetic sensitivity of x-rays, with the technique of conventional specular
reflectivity, a well established tool for the structural studies of the chemical makeup of thin
films and artificial multilayer systems. The theory of resonant magnetic scattering within
dipole approximation combined with the specular reflectivity condition suggests that the
strongest effects are in the lower incident angle regime using circularly polarized x-rays. By
using soft and hard x-rays structures on a scale of a few to several hundreds of Å are probed,
which is the dimensions of the thicknesses of the layers of most thin film and multilayers
systems.
In order to retrieve quantitative information from the measured magnetic reflectivity curves, an
approach for visible light magneto-optical effects based on known dielectric tensors of the
sample has been adopted and applied for soft and hard x-ray resonant scattering. Sample
absorption and polarization changes in the sample are accounted for. Besides the structural
composition, the thickness of the individual layers and the index of refraction, also the
magnetic spin configuration can be chosen with arbitrary moment direction and magnitude by
modifying the off-diagonal terms in the dielectric tensor. The magnetic optical constants,
which determine the magnitude of the magnetic moments, are experimentally determined via
MCD absorption measurements and then retrieving the real part through the Kramers-Kronig
transformation of the measured imaginary part. This is shown in this work for several 3d
transition metals and edges. The simulations are sensitive to a variety of different spin
configurations: spiral spin structures, magnetic dead layers and of collinear alignment.
Experimentally the magnetic reflectivity of 3d transition metals has to distinguish between the
two available possible absorbtion edges, L and K, lying in different x-ray regions. The L-edges
are situated in the soft x-ray region and exhibit large enhancements of the magnetic cross
section, while the K-edges lie in the hard x-ray regime and show much smaller effects. In spite
of this handicap, the latter can be important due to the much larger penetration depth and better
Qz-resolution. The X13 beamline at the NSLS at Brookhaven National Laboratory consisting
of two branches for soft and hard-x ray operations, respectively, uses an elliptical polarized
wiggler (EPW), which produces circularly polarized x-rays in the orbit plane and allows fast
switching between left and right circular polarization. Lock-in detection is used to improve the
signal-to-noise ratio at the soft x-ray branch and single photon detection at the hard x-ray
branch to measure the magnetic signal. The EPW and the experimental setup was
commissioned to demonstrate the feasibility of magnetic x-ray experiments. Especially at the
hard x-ray beamline branch the small magnetic effects, less than 0.1% of the charge scattering,
were possible to detect. In order to satisfy the need for high flux the CMC-CAT beamline at the
APS in Argonne was used for magnetic hard x-ray reflectivity, providing an undulator
beamline where the high flux of linear polarized photons was converted into circular
polarization via a diamond phase plate, delivering much higher flux and better circular
polarization.
The sample used to demonstrate the feasibility of the method of magnetic reflectivity consists
of two multilayer structures of Fe/Cr on top of each other, where the iron spins of the upper are
ferromagnetically and of the lower antiferromagnetically coupled, representing an exchange
bias system. The sample was characterized with conventional x-ray reflectivity and MOKE
measurements in order to accurately determine the structural composition and magnetic
configuration (hysteresis loops), respectively. Magnetic reflectivity experiments on the L-edges
at the X13A beamline showed strong magnetic effects, which could be clearly identified as
ferromagnetic and antiferromagnetic Bragg peak contributions and simulation confirmed the
collinear alignment and full magnetization of the iron spins throughout the iron layers. Energyand
magnetic field dependent measurements complete the picture. By tuning the x-ray energy
to the chromium L-edge, a signal 20 times weaker compared with iron, demonstrates that the
weak magnetic moment in the chromium layers could be detected. Especially the AFM
contribution shows strong effects which could be qualitatively and quantitatively evaluated.
Simulation show clearly that the magnetic moment is concentrated at the interfaces and could
be approximated to a magnetic layer with an effective thickness of about 0.5 Å assuming a step
function in the magnetization profile.
Soft x-ray data usually suffer from strong absorption and the limited Qz-range and resolution
and therefore the use of hard x-rays seems desirable to probe the whole sample. Magnetic hard
x-ray reflectivity measurements on the Fe/Cr double multilayer carried out at the CMC
beamline by switching the magnetic field on the sample show clear magnetic Bragg reflection
at the ferromagnetic structural peaks. They are very well reproduced by simulations and thus
confirm the collinear alignment of the iron spins. In order to probe the AFM spin configuration
the helicity of the photon beam has to be switched with constant magnetic field. In spite of
complications in the reflectivity spectra it was possible to extract the relative orientation of the
AFM to FM spin configuration in the two multilayers.
In summary the work showed for the example of an Fe/Cr double multilayer that magnetic soft
and hard x-ray reflectivity can be applied to retrieve information about the magnetization
profile of thin magnetic films and multilayer, and can compliment polarized neutron scattering
Greetings Music Lovers
No full textThe premiere of Steve Urquhart's new audio documentary exploring the life and work of BBC Radio Lancashire broadcaster and Wire contributor Steve Barker.
May 2018 sees veteran Wire writer and dub/roots columnist Steve Barker celebrate 40 years at BBC Radio Lancashire, where his legendary freeform show On The Wire continues to promote underground and new music every Saturday night at midnight. This special audio portrait charts Steve’s influential (and occasionally turbulent) four decades on air. On The Wire was among the first to interview The Smiths and Depeche Mode; it played 808 State’s “Pacific State” and A Guy Called Gerald’s “Voodoo Ray” before anyone else; it even staged a free Fall gig at Clitheroe Castle. It’s been threatened by BBC cuts – twice – and both times saved with the help of its fiercely loyal listeners across Lancashire and worldwide.
Made by Steve Urquhart – producer of the recent BBC Radio 3 feature A Portrait Of Val Wilmer, chronicling another renowned Wire contributor – Greetings Music Lover features rare archive material plus new interviews from On-U Sound’s Adrian Sherwood, Lee ‘Scratch’ Perry, David Rodigan, Stuart Maconie, The Wire’s Tony Herrington and Derek Walmsley, plus various contributors to On The Wire over the years, and Steve Barker himself
Steve Stockman, Keynote Session 1
No full textKeynote speaker Steve Stockman is the author of Walk On: The Spiritual Journey of U2. He is also a pop culture critic and weekly radio host on BBC Radio Ulster. Stockman is the Presbyterian Chaplain of Queens University in Belfast, Ireland
Steve Almond, 32nd Annual ODU Literary Festival
No full textSteve Almond is the author of two story collections, My Life in Heavy Metal and The Evil B.B. Chow, the novel Which Brings Me to You (with Julianna Baggott), and the non-fiction book Candyfreak. His new book is a collection of essays, (Not That You Asked). He lives outside Boston with his wife, two children, and mounting debt. His online home is www.stevenalmond.com
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