Ricardo Alejandre Aguilar

A New Robust Sliding-Mode Observer Design for Monitoring in Chemical Reactors

The robust observer design for the online estimation of heat in continuous stirred tank reactors, containing nonstructured uncertainties within its model description as well as noisy temperature measurements, is addressed. The proposed observer contains a slidingmode term and is designed based on Differential Algebraic technique. The concept of the algebraic observability for a given class of model uncertainty is introduced. It is applied to the uncertainty estimation from noisy temperature measurements providing a simple observer structure which turns out to be robust against output (sensors) noises as well as sustained disturbances. The performance of this observer is shown to be calculated numerically. The obtained results look promising for possible industrial applications. @DOI: 10.1115/1.1789534#

Triatoma bassolsae sp. n. do México, com uma chave para as espécies do complexo "phyllosoma" (Hemiptera, Reduviidae)

According to the descriptions of five closely related species of the genus Triatoma Laporte, 1832: T. phyllosoma (Burmeister, 1835), T. pallidipennis (Stal, 1872), T. picturata Usinger, 1939, T. longipennis Usinger, 1939 and T. mazzottii Usinger, 1941 and further published studies, these species could be included in a specific complex named as the species formerly described. All these species are typical from Mexico and another species was found in the same country, in the State of Puebla: Triatoma bassolsae sp. n. This species was morphologically compared with the other five of the phyllosoma complex, including the external male genitalia. The most important characters used to separate T. bassolsae from T. phyllosoma (which is the most similar to the other species) are the morphometric relationships on the head, with a longer anteocular region and a significant longer second rostral segment, a long and conspicuous pilosity in different areas of the body and specially on the head, and the characters of the anterolateral, lateral and discal tubercles of the pronotum, very long and sharp in the new species. The male genitalia has several differences between T. bassolsae and T. phyllosoma specially significant on the surface of the endosome process and on the branches of the phallosome support, separated at the apex in the new species. Types and paratypes are incorporated in the respective institutions in Mexico DF and Rio de Janeiro.

PI observers for uncertainty estimation in continuous chemical reactors

The estimation of heat of reaction in continuous stirred tank reactors, from temperature measurements is addressed in this paper. The uncertainty observer proposed consists of proportional and integral (PI) actions and is based on differential algebraic techniques, therefore the algebraic observability condition for the uncertainty estimation from temperature measurements is easily verified and the observer structure is very simple, which leads to feasible implementation. The structure of the proposed observer is robust against noisy measurements and sustained disturbances. The performance of the observer is shown using numerical simulation.

Estimation for HIV transmission using a reduced order uncertainty observer

In this work, the problem of estimating the susceptible and the recent infective, not yet in treatment, groups in a determinate male homosexual population is addressed. The estimation methodology is based on reduced order observers with proportional and integral measurement error contribution, considering measurements of male homosexual population and infective, undergoing treatment, groups. These estimates allow inference, in some sense, of the HIV transmission dynamics in order to propose a more adequate health policy. Numerical simulations were carried out showing the good performance of the estimation methodology proposed.

Morphology and Morphometry of the Scutellum of Six Species in the Genus Meccus (Hemiptera: Triatominae)

ABSTRACT: n We studied the morphology and morphometry of scutella from six species of the hemipteran genus Meccus to identify new tools to help solve taxonomic problems in closely related insect species of epidemiological relevance. Scutellum samples were observed by scanning electron microscopy and were subjected to morphometric analysis. The results mainly show differences in central depression shape, posterior process, and vestiture. We found significant dimensional differences in scutellum morphometry and a clear sexual dimorphism among species. A combination of morphology and morphometry can be used to differentiate among species of the genus Meccus.

Synchronization of an uncertain chaotic system based on sliding mode control

In this paper we deal with the synchronization and parameter estimations of an uncertain Rikitake system. The strategy consists of proposing a slave system which has to follow asymptotically the unknown Rikitake system, refereed as master system. The gains of the slave system are adjusted continually according to a convenient adaptation control law, until the measurable output errors converge to zero. The convergence analysis is carried out by using Barbalats Lemma.

Nonlinear control based on uncertainty observer for a catalyst regenerator reactor

The temperature regulation problem of a class of catalyst regenerator reactor with complex behavior is addressed. Due the complex kinetics in this kind of process, the reaction heat is supposed unknown and an online uncertainty estimator based on a reduced order filter is proposed; this estimator produce adequate estimates of the reaction heat which are coupled with an input/output linearizing control law. The linearizing controller based on an online uncertainty estimator is equivalent to a PI controller, where new tuning rules for the controller gains are giving in terms of the closed-loop characteristic time and the characteristic estimation time.