60,862 research outputs found
Tricriticality and Reentrance in a Naive Spin-Glass Model
In this paper a spin-1 spin-glass model under the presence of a uniform
crystal field is investigated. It is shown that the model presents both
continuous and first-order phase transition separated by a tricritical point.
The phase diagram is obtained within the replica-symmetric solution and
exhibits reentrance phenomena at low temperatures. Possibly it is the simplest
model which can describe inverse freezing phenomena.Comment: 12 pages, 1 figur
Out-of-plane in situ cyclic testing of unreinforced stone masonry walls with distributed loads
The present paper reports an in situ experimental test campaign carried out on existing
buildings, in order to investigate the seismic behaviour of traditional masonry walls subject to
out-of-plane loads. For the testing proposes, an experimental test setup based on a selfequilibrated
scheme was developed and optimized to be applied in situ in two specimens on
original and strengthened conditions. The obtained results are presented and carefully
discussed namely from the reinforcement solutions’ efficiency point-of-view, as well as
compared to previous experimental data obtained for the same type of masonry walls.
Additionally, a simplified linearized displacement-based procedure was adapted in order to
characterize the nonlinear force-displacement relationship for unreinforced traditional
masonry walls and to analytically predict the experimental test results. The confrontation
between the experimental and the analytical results are presented and discussed
Induced higher-derivative massive gravity on a 2-brane in 4D Minkowski space
In this paper we revisit the problem of localizing gravity in a 2-brane
embedded in a 4D Minkowski space to address induction of high derivative
massive gravity. We explore the structure of propagators to find well-behaved
higher-derivative massive gravity induced on the brane. Exploring a special
case in the generalized mass term of the graviton propagator we find a model of
consistent higher order gravity with an additional unitary massive spin-2
particle and two massless particles: one spin-0 particle and one spin-1
particle. The condition for the absence of tachyons is satisfied for both
`right' and `wrong' signs of the Einstein-Hilbert term on the 2-brane. We also
find the Pauli-Fierz mass term added to the new massive gravity in three
dimensions and recover the low dimensional DGP model.Comment: Latex, 12 pages, no figure; refs added, version to appear in PL
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