Min-Max Predictive Control of a Pilot Plant using a QP Approach

47th IEEE Conference on Decision and Control 9-11 Dec. 2008The practical implementation of min-max MPC (MMMPC) controllers is limited by the computational burden required to compute the control law. This problem can be circumvented by using approximate solutions or upper bounds of the worst possible case of the performance index. In a previous work, the authors presented a computationally efficient MMMPC control strategy in which a close approximation of the solution of the min-max problem is computed using a quadratic programming problem. In this paper, this approach is validated through its application to a pilot plant in which the temperature of a reactor is controlled. The behavior of the system and the controller are illustrated by means of experimental results

Isotope effects on the lattice parameter of cubic SiC

Path-integral molecular dynamics simulations in the isothermal-isobaric (NPT) ensemble have been carried out to study the dependence of the lattice parameter of 3C-SiC upon isotope mass. This computational method allows a quantitative and nonperturbative study of such anharmonic effect. Atomic nuclei were treated as quantum particles interacting via a tight-binding-type potential. At 300 K, the difference Delta a between lattice parameters of 3C-SiC crystals with 12C and 13C amounts to 2.1 x 10^{-4} A. The effect due to Si isotopes is smaller, and amounts to 3.5 x 10^{-5} A when replacing 28Si by 29Si. Results of the PIMD simulations are interpreted in terms of a quasiharmonic approximation for the lattice vibrations.Comment: 4 pages, 3 figure

La intensidad de la externalización hotelera y sus beneficios y riesgos percibidos

Este trabajo se centra en identificar el papel de la estrategia de externalización en los hoteles. Para ello, se analiza los niveles de externalización actual y deseada. El artículo intenta determinar qué ventajas así como los riesgos que perciben los directivos de esta estrategia. Por otra parte se analiza la relación entre el tamaño, categoría y tipo de hotel con la externalización. Los resultados indican que el nivel de externalización es bastante usado. Por otra parte, los beneficios que perciben los directivos son más tácticos que estratégicos. Existe una relación entre la externalización y el tamaño del hotel

Fundamentals and Applications of Surface-Enhanced Raman Spectroscopy (SERS)

When a molecule is adsorbed on some metallic nanostructured surfaces such as silver, copper or gold, it can undergo an enormous enhancement of the Raman signal giving rise to the so called Surface-Enhanced Raman Scattering (SERS). The high sensitivity of this effect allows an accurate structural study of adsorbates at very low concentrations. The SERS effect has historically been associated with the substrate roughness on two characteristic length scales. Surface roughness on the 10 to 100 nm length scale supports localized plasmon resonances which are considered as the dominant enhancement mechanism of SERS (Electromagnetic Enhancement Mechanism: SERS-EM). It is usually accepted that these electromagnetic resonances can increase the scattered intensity by an average factor of ca. 104 to 107. A secondary mechanism often thought to require atomic scale roughness is referred to as Charge Transfer (CT) Enhancement Mechanism (SERS-CT). This mechanism involves the photoinduced transfer of an electron from the metal to the adsorbate or vice versa and involves new electronic excited CT states which result from adsorbate–substrate chemical interactions. It is also estimated that such SERS-CT mechanism can enhance the scattering cross-section by a factor of ca. 10 to 102. These two mechanisms can operate simultaneously, depending on the particular systems and experimental conditions, making difficult to recognize each one and to estimate their relative magnitude in a particular spectrum.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS

The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW

Control Predictivo Mín-Máx de una planta piloto

Este trabajo muestra la aplicación de una estrategia de control predictivo mín máx basado en modelos (Min-Max Model Predictive Control, MMMPC) a una planta piloto en la que se controla la temperatura de un reactor. Para calcular la acción de control se utiliza una aproximación del peor caso, que permite calcular una solución muy cercana a la del problema mín-máx con un coste computacional mucho menor. Por tanto, es un algoritmo cuya complejidad hace factible una implementación en tiempo real para valores típicos de los horizontes de predicción y control. El comportamiento del proceso y del controlador se ilustran mediante resultados experimentalesMinisterio de Eduación y Ciencia DPI2004-07444Ministerio de Eduación y Ciencia DPI2005-0456

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2) training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6±1.6 years) were randomized into hyperbaric-hyperoxic (HH) training (n=6) and normobaric normoxic (NN) training (n=6) groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid), plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX]), arterial blood gases, acid-base balance, bases excess (BE), and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max) and peak power output (PPO) were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size) after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players

Babesia Bovis Ligand-Receptor Interaction: AMA-1 Contains Small Regions Governing Bovine Erythrocyte Binding

Apical membrane antigen 1 is a microneme protein which plays an indispensable role during Apicomplexa parasite invasion. The detailed mechanism of AMA-1 molecular interaction with its receptor on bovine erythrocytes has not been completely defined in Babesia bovis. This study was focused on identifying the minimum B. bovis AMA-1-derived regions governing specific and high-affinity binding to its target cells. Different approaches were used for detecting ama-1 locus genetic variability and natural selection signatures. The binding properties of twelve highly conserved 20-residue-long peptides were evaluated using a sensitive and specific binding assay based on radio-iodination. B. bovis AMA-1 ectodomain structure was modelled and refined using molecular modelling software. NetMHCIIpan software was used for calculating B-and T-cell epitopes. The B. bovis ama-1 gene had regions under functional constraint, having the highest negative selective pressure intensity in the Domain I encoding region. Interestingly, B. bovis AMA-1-DI (100YMQKFDIPRNHGSGIYVDLG119 and120GYESVGSKSYRMPVGKCPVV139 ) and DII (302CPMHPVRDAIFGKWSGGSCV321 )-derived peptides had high specificity interaction with erythrocytes and bound to a chymotrypsin and neuraminidase-treatment sensitive receptor. DI-derived peptides appear to be exposed on the protein’s surface and contain predicted B-and T-cell epitopes. These findings provide data (for the first-time) concerning B. bovis AMA-1 functional subunits which are important for establishing receptor-ligand interactions which could be used in synthetic vaccine development

Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations

We present the study of nineteen low X-ray luminosity galaxy clusters (L$_X \sim$ 0.5--45 $\times$ $10^{43}$ erg s$^{-1}$), selected from the ROSAT Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin et al. 1998) and the revised version of Mullis et al. (2003) in the redshift range of 0.16 to 0.7. This is the introductory paper of a series presenting the sample selection, photometric and spectroscopic observations and data reduction. Photometric data in different passbands were taken for eight galaxy clusters at Las Campanas Observatory; three clusters at Cerro Tololo Interamerican Observatory; and eight clusters at the Gemini Observatory. Spectroscopic data were collected for only four galaxy clusters using Gemini telescopes. With the photometry, the galaxies were defined based on the star-galaxy separation taking into account photometric parameters. For each galaxy cluster, the catalogues contain the PSF and aperture magnitudes of galaxies within the 90\% completeness limit. They are used together with structural parameters to study the galaxy morphology and to estimate photometric redshifts. With the spectroscopy, the derived galaxy velocity dispersion of our clusters ranged from 507 km~s$^{-1}$ for [VMF98]022 to 775 km~s$^{-1}$ for [VMF98]097 with signs of substructure. Cluster membership has been extensively discussed taking into account spectroscopic and photometric redshift estimates. In this sense, members are the galaxies within a projected radius of 0.75 Mpc from the X-ray mission peak and with cluster centric velocities smaller than the cluster velocity dispersion or 6000 km~s$^{-1}$, respectively. These results will be used in forthcoming papers to study, among the main topics, the red cluster sequence, blue cloud and green populations; the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for publication in The Astronomical Journal. Some formatting errors fixe