764 research outputs found
Opening the GATE : systems thinking from the global assistive technology alliance
Purpose: This paper describes international actions to collaborate in the assistive technology (AT) arena and provides an update of programmes supporting AT globally.
Methods: The World Health Organisation (WHO) identifies the severe global uneven distribution of resources, expertise and extensive unmet need for AT, as well the optimistic substantial capability for innovations and developments in appropriate and sustainable AT design, development and delivery. Systems thinking and market shaping are identified as means to address these challenges and leverage the ingenuity and expertise of AT stakeholders.
Results: This paper is a ‘call to action’, showcasing emerging AT networks as exemplars of a distributed, but integrated mechanism for addressing AT needs globally, and describing the Global Alliance of Assistive Technology Organisations (GAATO) as a vehicle to facilitate this global networking.
Conclusion: Partners in this Global Alliance aim to advance the field of assistive technology by promoting shared research, policy advocacy, educating people and organisations within and outside the field, teaching, training and knowledge transfer by pulling together broad-based membership organisations
A fresh look at instrumentation - an introduction
The theme of "instrumentation between science, state and industry" does not square well with the venerable discourse which opposes "science" and "technology" in social studies of science. In this discourse, "technology" stands for the contrary of "science"; it represents the practical uses of science in society at large and is understood as separate from the somehow autonomous sphere of "science" (Layton 1971a). This vocabulary, widespread as it may be, is not very useful for our purposes, and, for that matter, for any inquiry into the role of instruments. Technology, in the sense of technical instruments and the knowledge systems that go with them, pervades all societal systems. There are technologies of science, of industry, of state, and so forth, and it would be ill-advised to assume that, in the end, they all flow out of "science." But even if the crude opposition of science and technology has little analytic value, the dual problem remains: how to effectively conceive the dynamic relationship between scientific spheres and other societal spheres, and how to conceive the role that technological matters play in this relationship
Inclusive cross section and double helicity asymmetry for pi^0 production in p+p collisions at sqrt(s) = 62.4 GeV
The PHENIX experiment presents results from the RHIC 2006 run with polarized
proton collisions at sqrt(s) = 62.4 GeV for inclusive pi^0 production at
mid-rapidity. Unpolarized cross section results are measured for transverse
momenta p_T = 0.5 to 7 GeV/c. Next-to-leading order perturbative quantum
chromodynamics calculations are compared with the data, and while the
calculations are consistent with the measurements, next-to-leading logarithmic
corrections improve the agreement. Double helicity asymmetries A_LL are
presented for p_T = 1 to 4 GeV/c and probe the higher range of Bjorken_x of the
gluon (x_g) with better statistical precision than our previous measurements at
sqrt(s)=200 GeV. These measurements are sensitive to the gluon polarization in
the proton for 0.06 < x_g < 0.4.Comment: 387 authors from 63 institutions, 10 pages, 6 figures, 1 table.
Submitted to Physical Review D. Plain text data tables for the points plotted
in figures for this and previous PHENIX publications are (or will be)
publicly available at http://www.phenix.bnl.gov/papers.htm
Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p+p collisions at sqrt(s)=62.4 GeV
Unpolarized cross sections and double-helicity asymmetries of
single-inclusive positive and negative charged hadrons at midrapidity from p+p
collisions at sqrt(s)=62.4 GeV are presented. The PHENIX measurements for 1.0 <
p_T < 4.5 GeV/c are consistent with perturbative QCD calculations at
next-to-leading order in the strong coupling constant, alpha_s. Resummed pQCD
calculations including terms with next-to-leading-log accuracy, yielding
reduced theoretical uncertainties, also agree with the data. The
double-helicity asymmetry, sensitive at leading order to the gluon polarization
in a momentum-fraction range of 0.05 ~< x_gluon ~< 0.2, is consistent with
recent global parameterizations disfavoring large gluon polarization.Comment: PHENIX Collaboration. 447 authors, 12 pages, 5 figures, 5 tables.
Submitted to Physical Review
Inclusive cross section and single-transverse-spin asymmetry for very forward neutron production in polarized p+p collisions at sqrt(s)=200 GeV
The energy dependence of the single-transverse-spin asymmetry, A_N, and the
cross section for neutron production at very forward angles were measured in
the PHENIX experiment at RHIC for polarized p+p collisions at sqrt(s)=200 GeV.
The neutrons were observed in forward detectors covering an angular range of up
to 2.2 mrad. We report results for neutrons with momentum fraction of x_F=0.45
to 1.0. The energy dependence of the measured cross sections were consistent
with x_F scaling, compared to measurements by an ISR experiment which measured
neutron production in unpolarized p+p collisions at sqrt(s)=30.6--62.7 GeV. The
cross sections for large x_F neutron production for p+p collisions, as well as
those in e+p collisions measured at HERA, are described by a pion exchange
mechanism. The observed forward neutron asymmetries were large, reaching
A_N=-0.08+/-0.02 for x_F=0.8; the measured backward asymmetries, for negative
x_F, were consistent with zero. The observed asymmetry for forward neutron
production is discussed within the pion exchange framework, with interference
between the spin-flip amplitude due to the pion exchange and nonflip amplitudes
from all Reggeon exchanges. Within the pion exchange description, the measured
neutron asymmetry is sensitive to the contribution of other Reggeon exchanges
even for small amplitudes.Comment: 383 authors, 16 pages, 18 figures, 6 tables. Submitted to Phys. Rev.
D. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Cold Nuclear Matter Effects on J/psi Yields as a Function of Rapidity and Nuclear Geometry in Deuteron-Gold Collisions at sqrt(s_NN) = 200 GeV
We present measurements of J/psi yields in d+Au collisions at sqrt(s_NN) =
200 GeV recorded by the PHENIX experiment and compare with yields in p+p
collisions at the same energy per nucleon-nucleon collision. The measurements
cover a large kinematic range in J/psi rapidity (-2.2 < y < 2.4) with high
statistical precision and are compared with two theoretical models: one with
nuclear shadowing combined with final state breakup and one with coherent gluon
saturation effects. To remove model dependent systematic uncertainties we also
compare the data to a simple geometric model. We find that calculations where
the nuclear modification is linear or exponential in the density weighted
longitudinal thickness are difficult to reconcile with the forward rapidity
data.Comment: 449 authors from 66 institutions, 6 pages, 3 figures. Submitted to
Physical Review Letters. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be) publicly
available at http://www.phenix.bnl.gov/papers.htm
Transverse momentum dependence of J/psi polarization at midrapidity in p+p collisions at sqrt(s)=200 GeV
We report the measurement of the transverse momentum dependence of inclusive
J/psi polarization in p+p collisions at sqrt(s)=200 GeV performed by the PHENIX
Experiment at RHIC. The polarization is studied in the helicity,
Gottfried-Jackson, and Collins-Soper frames for p_T < 5 GeV/c and |y| < 0.35.
The J/psi polarization in the helicity and Gottfried-Jackson frames is
consistent with zero for all transverse momenta, with a slight (1.8 sigma)
trend towards longitudinal polarization for transverse momenta above 2 GeV/c.
No conclusion is allowed due to the limited acceptance in the Collins-Soper
frame and the uncertainties of the current data. The results are compared to
observations for other collision systems and center of mass energies and to
different quarkonia production models.Comment: 384 authors from 62 institutions, 11 pages, 9 figures, 2 tables. v2
is expanded version submitted to Physical Review D. Plain text data tables
for the points plotted in figures are available at
http://www.phenix.bnl.gov/papers.htm
Upsilon (1S+2S+3S) production in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and cold-nuclear matter effects
The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p
collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX
experiment at the Relativistic Heavy-Ion Collider. Cross sections for the
inclusive Upsilon(1S+2S+3S) production are obtained. The inclusive yields per
binary collision for d+Au collisions relative to those in p+p collisions
(R_dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going
direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going
direction. The measured results are compared to a nuclear-shadowing model,
EPS09 [JHEP 04, 065 (2009)], combined with a final-state breakup cross section,
sigma_br, and compared to lower energy p+A results. We also compare the results
to the PHENIX J/psi results [Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity
dependence of the observed Upsilon suppression is consistent with lower energy
p+A measurements.Comment: 495 authors, 11 pages, 9 figures, 5 tables. Submitted to Phys. Rev.
C. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Identified charged hadron production in p+p collisions at sqrt(s)=200 and 62.4 GeV
Transverse momentum distributions and yields for , ,
and in collisions at =200 and 62.4 GeV at midrapidity
are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider
(RHIC). These data provide important baseline spectra for comparisons with
identified particle spectra in heavy ion collisions at RHIC. We present the
inverse slope parameter , mean transverse momentum and
yield per unit rapidity at each energy, and compare them to other
measurements at different in and collisions. We
also present the scaling properties such as scaling, scaling on the
spectra between different energies. To discuss the mechanism of the
particle production in collisions, the measured spectra are compared to
next-to-leading-order or next-to-leading-logarithmic perturbative quantum
chromodynamics calculations.Comment: 431 authors from 62 institutions, 32 pages, 23 figures, and 18
tables. Submitted to Physical Review C. Plain text data tables for the points
plotted in figures for this and previous PHENIX publications are (or will be)
publicly available at http://www.phenix.bnl.gov/papers.htm
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