Large Scale Structure and Cosmic Rays revisited

We investigate the possibility that ultra high energy cosmic rays (E > 10^19 eV) are related to the distribution of matter on large scales. The large scale structure (LSS) data stems from the recent IRAS PSCz redshift survey. We present preliminary predictions drawn from an anisotropic distribution of sources which follows the galaxy distribution.Comment: 6 pages, 2 figures, uses World Scientific style. To appear in the proceedings of "Third International Workshop on New Worlds in Astro-Particle Physics", 1-3 Set. 2000, Faro, Portugal and X ENAA, 27-28 Jul. 2000, Lisbon, Portuga

Detection of the compressed primary stellar wind in eta Carinae

A series of three HST/STIS spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from eta Carinae. We identify these arcs with the shell-like structures, seen in the 3D hydrodynamical simulations, formed by compression of the primary wind by the secondary wind during periastron passages.Comment: Accepted for publication in the Astrophysical Journal Letter

Robust control of the distributed solar collector field ACUREX using MPC for tracking

17th IFAC World Congress 2008. Seoul (Korea). 06/07/2008This paper presents the application of a robust model predictive control for tracking of piece-wise constant references (RMPCT) to a distributed collector field, ACUREX, at the solar power plant of PSA (Solar Plant of Almería). The main characteristic of a solar power plant is that the primary energy source, solar radiation, cannot be manipulated. Solar radiation varies throughout the day, causing changes in plant dynamics and strong disturbances in the process. The real plant is assumed to be modeled as a linear system with additive bounded uncertainties on the states. Under mild assumptions, the proposed RMPCT can steer the uncertain system in an admissible evolution to any admissible steady state, that is, under any change of the set point. This allows us to reject constant disturbances compensating the effect of then changing the setpoint

On the changes in the physical properties of the ionized region around the Weigelt structures in Eta Carinae over the 5.54-yr spectroscopic cycle

We present HST/STIS observations and analysis of two prominent nebular structures around the central source of Eta Carinae, the knots C and D. The former is brighter than the latter for emission lines from intermediate or high ionization potential ions. The brightness of lines from intermediate and high ionization potential ions significantly decreases at phases around periastron. We do not see conspicuous changes in the brightness of lines from low ionization potential (<13.6 eV) that the total extinction towards the Weigelt structures is that the total extinction towards the Weigelt structures is AsubV =2/0. that the total extinction towards the Weigelt structures is AV = 2.0. Weigelt C and D are characterized by an electron density of that the total extinction towards the Weigelt structures is AV = 2.0. Weigelt C and D are characterized by an electron density of 10exp6.9 cm-3 that does not significantly change throughout the orbital cycle. The electron temperature varies from 5500 K (around periastron) to 7200 K (around apastron). The relative changes in the brightness of He I lines are well reproduced by the variations in the electron temperature alone. We found that, at phases around periastron, the electron temperature seems to be higher for Weigelt C than that of D. The Weigelt structures are located close to the Homunculus equatorial plane, at a distance of about 1240 AU from the central source. From the analysis of proper motion and age, the Weigelt complex can be associated with the equatorial structure called the Butterfly Nebula surrounding the central binary system.Comment: 19 pages, 18 figure

Introducing Linear Matrix Inequalities in a Control Course

7TH IFAC SYMPOSIUM ON ADVANCES IN CONTROL EDUCATION 21/06/2006 MadridThe important role that linear matrix inequalities have attained in the last years makes it compulsory to include them in the education of a control engineer. As the development of efficient semidefinite programming algorithms date from the early nineties, there is a lack of teaching experience in this field (at least when it is compared with other well established aspects of control theory). This paper proposes a simple way to introduce linear matrix inequalities in a control course. The main objective of the paper is to show that in the formulation of (robust) control problems as linear matrix inequalities a very reduced number of elementary technical results are required. It is illustrated how to introduce, in a progressive way, these technical results along with motivating examples. All of this is done in such a way that it facilitates the assimilation of this important subject. The presented methodology has been successfully applied for more than four years in a doctoral course on control theory

Topical insecticide treatments to protect dogs from sand fly vectors of leishmaniasis.

We compared the susceptibility of sand fly vectors to four topical insecticide treatments applied to domestic dogs, a reservoir of human leishmaniasis. Dogs were exposed to sand flies pretreatment and at 1 week, 1 month, and 2 months posttreatment. Sand fly bloodfeeding and survival rate of both fed and unfed flies were significantly reduced by the permethrin, deltamethrin, and fenthion treatments, but diazinon had no effect. The survival rate of bloodfed sand flies was reduced by up to 86% with deltamethrin collars. The antifeeding effect suggests that deltamethrin collars may be recommended to dog owners to protect their pets from sandfly- borne diseases. The combined effects on sand fly feeding and survival indicate that epidemiologic, community-based trials are warranted to test whether deltamethrin collars could reduce the incidence of canine and, hence, human leishmaniasis

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