23,324 research outputs found
Out-of-plane seismic response of stone masonry walls: experimental and analytical study of real piers
This paper presents the application of an existing simplified displacement-based procedure to the
characterization of the nonlinear force-displacement relationship for the out-of-plane behaviour of
unreinforced traditional masonry walls. According to this procedure, tri-linear models based on three
different energy based criteria were constructed and confronted with three experimental tests on
existing stone masonry constructions. Moreover, a brief introduction is presented regarding the main
characteristics of the in situ cyclic testing recently carried out using distributed loads, as well as results
obtained during the experimental campaigns performed. The comparison between the experimental and the analytical results are presented and discussed
Enhancing with the -penguin
Lepton flavor violation (LFV) has been observed in neutrino oscillations. For
charged lepton FV decays only upper limits are known, but sizable branching
ratios are expected in many neutrino mass models. High scale models, such as
the classical supersymmetric seesaw, usually predict that decays are roughly a factor maller than the corresponding decays . Here we demonstrate that the -penguin diagram can give an
enhancement for decays in many extensions of the MSSM. We first
discuss why the -penguin is not dominant in the MSSM with seesaw and show
that much larger contributions from the -penguin are expected in general.
We then demonstrate the effect numerically in two example models, namely, the
supersymmetric inverse seesaw and R-parity violating supersymmetry.Comment: 5 pages; v2: minor corrections, final version to appear in PR
Further results on elementary Lie algebras and Lie A-algebras.
A finite-dimensional Lie algebra L over a field F of characteristic zero is called elementary if each of its subalgebras has trivial Frattini ideal; it is an A-algebra if every nilpotent subalgebra is abelian. This paper is a continuation of the study of these algebras initiated by the authors in a previous paper. If we denote by , , , , the classes of A-algebras, almost algebraic algebras, E-algebras, elementary algebras and -free algebras respectively, then it is shown that: \mathcal{L} \subset \Phi \subset \mathcal{G} \mathcal{L} \subset \mathcal{A} \subset \mathcal{E} \mathcal{G} \cap \mathcal{A} = \mathcal{L}. It is also shown that if L is a semisimple Lie algebra all of whose minimal parabolic subalgebras are -free then L is an A-algebra, and hence elementary. This requires a number of quite delicate properties of parabolic subalgebras. Finally characterisations are given of -algebras and of Lie algebras all of whose proper subalgebras are elementary
eta - eta' - glueball mixing
We have revisited glueball mixing with the pseudoscalar mesons in the MIT bag
model scheme. The calculation has been performed in the spherical cavity
approximation to the bag using two different fermion propagators, the cavity
and the free propagators. We obtain a very small probability of mixing for the
eta at the level of $0.04-0.1% and a bigger for the eta' at the level of 4-12%.
Our results differ from previous calculations in the same scheme but seem to
agree with the experimental analysis. We discuss the origin of our difference
which stems from the treatment of our time integrations.Comment: 21 pages, 7 figure
Edible films and coatings : from novel materials to nanotechnological applications
The food industry constantly seeks new strategies to increase the storability of foods and to
improve the existent technology. In the last years, edible coatings/films have been
considered as one of the potential technologies that can achieve those objectives, ensuring
the microbial safety and the preservation of food from the influence of external factors.
Significant innovations constantly appear in food packaging, always with the objective of
creating a more efficient quality preservation system while improving foods’ attractiveness
and marketability. One of the main worries while developing such innovations is the use of
renewable sources for the packaging materials, such as hydrocolloids from biological origin,
and the incorporation of functional ingredients that can be used e.g. as antioxidants and
antimicrobial agents.
Our work until the present moment has involved most of the important features of this
technology, namely: materials (new sources of raw materials for the production of edible
coatings/films were sought and the materials were characterized); properties of the
coatings/films (physical, chemical, thermal, mechanical and transport properties - in
particular those related to moisture, oxygen, carbon dioxide exchange through the
coating/film - were evaluated); incorporation of active compounds (natural antimicrobials and
antioxidants were incorporated); applications to food products and its consequences in e.g.
the extension of their shelf life.
Finally, nano-engineered coating and films are being developed, and a report will be given on
that subject with the latest developments achieved in our lab
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