159,450 research outputs found
A covariant and gauge invariant formulation of the cosmological "backreaction"
Using our recent proposal for defining gauge invariant averages we give a
general-covariant formulation of the so-called cosmological "backreaction". Our
effective covariant equations allow us to describe in explicitly gauge
invariant form the way classical or quantum inhomogeneities affect the average
evolution of our Universe.Comment: 12 pages, no figures. Typos corrected, matches version to appear in
JCA
Comparison of Models of Critical Opacity in the Quark-Gluon Plasma
In this work we discuss two methods of calculation of quark propagation in
the quark-gluon plasma. Both methods make use of the Nambu-Jona-Lasinio model.
The essential difference of these calculations is the treatment of
deconfinement. A model of confinement is not included in the work of Gastineau,
Blanquier and Aichelin [hep-ph/0404207], however, the meson states they
consider are still bound for temperatures greater than the deconfinement
temperature T_c. On the other hand, our model deals with unconfined quarks and
includes a description of the q(bar)q resonances found in lattice QCD studies
that make use of the maximum entropy method (MEM). We compare the q{bar)q cross
sections calculated in these models.Comment: 7 pages and 4 figures RevTe
Design and prototype fabrication of a 30 tesla cryogenic magnet
A liquid neon cooled magnet was designed to produce 30 teslas in steady operation. To ensure the correctness of the heat transfer relationships used, supercritical neon heat transfer tests were made. Other tests made before the final design included tests on the effect of the magnetic field on pump motors, tensile shear tests on the cryogenic adhesives, and simulated flow studies for the coolant. The magnet will consist of two pairs of coils, cooled by forced convection of supercritical neon. Heat from the supercritical neon will be rejected through heat exchangers which are made of roll bonded copper panels and are submerged in a pool of saturated liquid neon. A partial mock up coil was wound to identify the tooling required to wind the magnet. This was followed by winding a prototype pair of coils. The prototype winding established procedures for fabricating the final magnet and revealed slight changes needed in the final design
Perceptions of a service redesign by adults living with type 2 diabetes
<b>Aim:</b> This article is a report of a study conducted to explore the perceptions of adults with type 2 diabetes towards the service redesign.
<b>Background:</b> Diabetes is reaching epidemic proportions and the management of this chronic illness is changing in response to this challenge. In the United Kingdom, there is ongoing restructuring of healthcare services for people with chronic illnesses to ensure that their general health and clinical needs are met predominantly in primary care.
<b>Method:</b> An explorative qualitative approach was used. Eight focus groups were conducted with 35 people with type 2 diabetes in one urban location between 2003 and 2004. Five focus groups were conducted with people who had recently experienced the restructured service and three groups with people who had up to 2 years' experience of the new service. Concurrent data collection and thematic analysis were conducted by three researchers and credibility and verification sought by feedback to participants.
<b>Findings:</b> Five main themes were identified: impact of living with diabetes; understanding diabetes; drivers for organizational change; care in context and individual concerns. Participants identified issues for ongoing development of the service.
<b>Conclusion:</b> People with type 2 diabetes appreciate their care management within the primary care setting where there has been investment in staff to deliver this care. Healthcare resources are required to support the development of staff and the necessary infrastructure to undertake management in primary care. Policy makers need to address the balance of resources between primary and secondary care
Higgs Phenomenology of Minimal Universal Extra Dimensions
The minimal model of Universal Extra Dimensions (MUED) is briefly reviewed.
We explain how the cross-sections for Higgs production via gluon fusion and
decay into two photons are modified, relative the the Standard Model (SM)
values, by KK particles running in loops, leading to an enhancement of the gg
to h to two photons and gg to h to W+W- cross-sections. ATLAS and CMS searches
for the SM Higgs in these channels are reinterpreted in the context of MUED and
used to place new limits on the MUED parameter space. Only a small region of
between 1 and 3 GeV around mh = 125 GeV for 500 GeV < 1/R < 1600 GeV remains
open at the 95 % confidence level.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011),
Paris, France, November 14-18 2011, 3 pages, 4 figure
Global Market Integration and National Sovereignty
In this paper, we first trace the evolution of the global trading system from the 19th century to the present-day GATT/WTO arrangements, calling attention to the key roles of reciprocity and nondiscrimination, and we note how the system is now challenged by the new paradigm of global market integration. We then consider the recent plethora of free trade agreements (FTAs), including those between industrial and developing countries, and their uneasy relationship with a multilateral system based on non-discrimination.. Thereafter, we seek to identify the boundaries of the WTO and examine how the potential expansion of these boundaries extension and weakening of the effectiveness and influence of the WTO.Reciprocity, Non-Discrimination; Boundaries of WTO Regime
European markets for NFC: supply and demand issues
orange juice, NFC, Europe, supply, demand, Agribusiness,
The economics of garbage collection
This paper argues that economic theory can improve our understanding of memory management. We introduce the allocation curve, as an analogue of the demand curve from microeconomics. An allocation curve for a program characterises how the amount of garbage collection activity required during its execution varies in relation to the heap size associated with that program. The standard treatment of microeconomic demand curves (shifts and elasticity) can be applied directly and intuitively to our new allocation curves. As an application of this new theory, we show how allocation elasticity can be used to control the heap growth rate for variable sized heaps in Jikes RVM
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