4,531,147 research outputs found
Uniform Decay of Local Energy and the Semi-Linear Wave Equation on Schwarzchild Space
We provide a uniform decay estimate of Morawetz type for the local energy of
general solutions to the inhomogeneous wave equation on a Schwarzchild
background. This estimate is both uniform in space and time, so in particular
it implies a uniform bound on the sup norm of solutions which can be given in
terms of certain inverse powers of the radial and advanced/retarded time
coordinate variables. As a model application, we show these estimates give a
very simple proof small amplitude scattering for nonlinear scalar fields with
higher than cubic interactions.Comment: 24 page
The Celtic Tiger Roars Defiantly: Corporation Tax in Ireland and Competition Within the European Union
Targets for producing high purity I-123
Tellurium powder in improved targets is bombarded with a cyclotron beam to produce Xe-123. Flowing gas streams carry the Xe-123 through one cold trap which removes Xe-123 that subsequently decays to I-123. During this bombardment energy is deposited in the target material causing its temperature to rise. Some of the tellurium vaporizes and subsequently condenses on surfaces that are cooler than the vaporization temperature. Provision is made for the repeated bombardment of this condensed tellurium
The Blue Bond Proposal
Soaring debt levels and the crisis in Greece has sharpened the focus on fiscal sustainability among eurozone members. The European Union has to tackle high debt levels in vulnerable states which are compounded by a hike in risk premiums on government bonds leading to a debt trap, while designing ways to efficiently finance debt. Furthermore, European solidarity with weaker states should not undermine incentives for individual members to pursue fiscally sustainable policies. This Policy Brief proposes a Blue Bond to resolve these challenges. The authors, Bruegel Non-resident Fellow Jakob von Weizsäcker and Jacques Delpla from Conseil d'Analyse �conomique, Paris, explain the economics behind their proposal, its institutional underpinnings and the implication of it on various participating countries.
What do older people do when sitting and why? Implications for decreasing sedentary behaviour
Background and Objectives:
Sitting less can reduce older adults’ risk of ill health and disability. Effective sedentary behavior interventions require greater understanding of what older adults do when sitting (and not sitting), and why. This study compares the types, context, and role of sitting activities in the daily lives of older men and women who sit more or less than average.
Research Design and Methods:
Semistructured interviews with 44 older men and women of different ages, socioeconomic status, and objectively measured sedentary behavior were analyzed using social practice theory to explore the multifactorial, inter-relational influences on their sedentary behavior. Thematic frameworks facilitated between-group comparisons.
Results:
Older adults described many different leisure time, household, transport, and occupational sitting and non-sitting activities. Leisure-time sitting in the home (e.g., watching TV) was most common, but many non-sitting activities, including “pottering” doing household chores, also took place at home. Other people and access to leisure facilities were associated with lower sedentary behavior. The distinction between being busy/not busy was more important to most participants than sitting/not sitting, and informed their judgments about high-value “purposeful” (social, cognitively active, restorative) sitting and low-value “passive” sitting. Declining physical function contributed to temporal sitting patterns that did not vary much from day-to-day.
Discussion and Implications:
Sitting is associated with cognitive, social, and/or restorative benefits, embedded within older adults’ daily routines, and therefore difficult to change. Useful strategies include supporting older adults to engage with other people and local facilities outside the home, and break up periods of passive sitting at home
The wave equation on the Schwarzschild metric II: Local decay for the spin 2 Regge Wheeler equation
Odd-type spin 2 perturbations of Einstein's equation can be reduced to the
scalar Regge-Wheeler equation. We show that the weighted norms of solutions are
in L^2 of time and space. This result uses commutator methods and applies
uniformly to all relevant spherical harmonics.Comment: AMS-LaTeX, 8 pages with 1 figure. There is an errata to this paper at
gr-qc/060807
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