7,660 research outputs found
Casimir interaction between two concentric cylinders at nonzero temperature
We study the finite temperature Casimir interaction between two concentric
cylinders. When the separation between the cylinders is much smaller than the
radii of the cylinders, the asymptotic expansions of the Casimir interaction
are derived. Both the low temperature and the high temperature regions are
considered. The leading terms are found to agree with the proximity force
approximations. The low temperature leading term of the temperature correction
is also computed and it is found to be independent of the boundary conditions
imposed on the larger cylinder.Comment: 6 pages, 1 figur
Misconduct resistance: the management of restricted drugs in the Western Australian public health service
We employ institutional theory to develop and present a framework – involving institutional drivers, organisational reactions, and outcomes – to examine and further understand misconduct resistance in public sector organisations. This framework is applied to an examination of efforts in the Western Australian public health service to prevent misconduct in the management of restricted drugs. We begin by clarifying a definition of misconduct resistance and then synthesise the extant literature develop a typology and framework of corruption resistance. The second part of the paper is a study in which the framework is applied to an examination of why and how the Western Australian public health service has endeavoured to prevent misconduct in the management of restricted drugs. Top-down imposition of regulations rather than shifts in individual employee attitudes is found. The paper concludes by outlining the potential contributions to theory and practice in approaches to increasing misconduct resistance in public health care organisations
Mode summation approach to Casimir effect between two objects
In this paper, we explore the TGTG formula from the perspective of mode
summation approach. Both scalar fields and electromagnetic fields are
considered. In this approach, one has to first solve the equation of motion to
find a wave basis for each object. The two T's in the TGTG formula are
T-matrices representing the Lippmann-Schwinger T-operators, one for each of the
objects. The two G's in the TGTG formula are the translation matrices, relating
the wave basis of an object to the wave basis of the other object. After
discussing the general theory, we apply the prescription to derive the explicit
formulas for the Casimir energies for the sphere-sphere, sphere-plane,
cylinder-cylinder and cylinder-plane interactions. First the T-matrices for a
plane, a sphere and a cylinder are derived for the following cases: the object
is imposed with general Robin boundary conditions; the object is
semitransparent; and the object is magnetodielectric. Then the operator
approach is used to derive the translation matrices. From these, the explicit
TGTG formula for each of the scenarios can be written down. Besides summarizing
all the TGTG formulas that have been derived so far, we also provide the TGTG
formulas for some scenarios that have not been considered before.Comment: 42 page
Conformal Mappings and Dispersionless Toda hierarchy
Let be the space consists of pairs , where is a
univalent function on the unit disc with , is a univalent function
on the exterior of the unit disc with and
. In this article, we define the time variables , on which are holomorphic with respect to the natural
complex structure on and can serve as local complex coordinates
for . We show that the evolutions of the pair with
respect to these time coordinates are governed by the dispersionless Toda
hierarchy flows. An explicit tau function is constructed for the dispersionless
Toda hierarchy. By restricting to the subspace consists
of pairs where , we obtain the integrable hierarchy
of conformal mappings considered by Wiegmann and Zabrodin \cite{WZ}. Since
every homeomorphism of the unit circle corresponds uniquely to
an element of under the conformal welding
, the space can be naturally
identified as a subspace of characterized by . We
show that we can naturally define complexified vector fields \pa_n, n\in \Z
on so that the evolutions of on
with respect to \pa_n satisfy the dispersionless Toda
hierarchy. Finally, we show that there is a similar integrable structure for
the Riemann mappings . Moreover, in the latter case, the time
variables are Fourier coefficients of and .Comment: 23 pages. This is to replace the previous preprint arXiv:0808.072
Probabilistic combinatorial optimization: Moments, semidefinite programming, and asymptotic bounds
10.1137/S1052623403430610SIAM Journal on Optimization151185-20
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