Power-Integrated Circuit Active Leakage Current Detector

Most of the failures of induction motors become insulation faults, causing a permanent damage. Using differential current transformers, a system capable of insulation fault detection was developed, based on the differential relay protection scheme. Both signal injection and fault detection circuitry were integrated in a single chip. The proposed scheme is faster than other existing protection and not restricted to protect induction motors, but several other devices (such as IGBTs) and systems. This paper explains the principle of operation of fault protection scheme and analyzes an integrated implementation through simulations and experimental results. A power-integrated circuit (PIC) implementation is presented.Fil: Bulacio, M. F.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Electronica; ArgentinaFil: González, Tomás Andrés. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Electronica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marinelli, Guido. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Electronica; ArgentinaFil: Alonso, Ramiro. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Electronica; ArgentinaFil: Tacca, Hernán Emilio. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Electronica; Argentin

Seizure localization using pre ictal phase-amplitude coupling in intracranial electroencephalography

Understanding changes in brain rhythms provides useful information to predict the onset of a seizure and to localize its onset zone in epileptic patients. Brain rhythms dynamics in general, and phaseamplitude coupling in particular, are known to be drastically altered during epileptic seizures. However, the neural processes that take place before a seizure are not well understood. We analysed the phaseamplitude coupling dynamics of stereoelectroencephalography recordings (30 seizures, 5 patients) before and after seizure onset. Electrodes near the seizure onset zone showed higher phase-amplitude coupling. Immediately before the beginning of the seizure, phase-amplitude coupling dropped to values similar to the observed in electrodes far from the seizure onset zone. Thus, our results bring accurate information to detect epileptic events during pre-ictal periods and to delimit the zone of seizure onset in patients undergoing epilepsy surgeryFil: Cámpora, Nuria Elide. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; ArgentinaFil: Mininni, Camilo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Kochen, Sara Silvia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Lew, Sergio Eduardo. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; Argentin

Multiclass classification of microarray data samples with a reduced number of genes

<p>Abstract</p> <p>Background</p> <p>Multiclass classification of microarray data samples with a reduced number of genes is a rich and challenging problem in Bioinformatics research. The problem gets harder as the number of classes is increased. In addition, the performance of most classifiers is tightly linked to the effectiveness of mandatory gene selection methods. Critical to gene selection is the availability of estimates about the maximum number of genes that can be handled by any classification algorithm. Lack of such estimates may lead to either computationally demanding explorations of a search space with thousands of dimensions or classification models based on gene sets of unrestricted size. In the former case, unbiased but possibly overfitted classification models may arise. In the latter case, biased classification models unable to support statistically significant findings may be obtained.</p> <p>Results</p> <p>A novel bound on the maximum number of genes that can be handled by binary classifiers in binary mediated multiclass classification algorithms of microarray data samples is presented. The bound suggests that high-dimensional binary output domains might favor the existence of accurate and sparse binary mediated multiclass classifiers for microarray data samples.</p> <p>Conclusions</p> <p>A comprehensive experimental work shows that the bound is indeed useful to induce accurate and sparse multiclass classifiers for microarray data samples.</p

Preparación de agregados enzimáticos de Lacasas y su aplicación en el tratamiento de colorantes textiles

It is well known that textile effluents have a dreadful impact on the environment. The biological treatment of these effluents has been performed by using extracellular enzymes from ligninolytic fungi immobilized without support systems. The objective of the present project was to evaluate the optimum conditions for the immobilization of laccase enzymes from Trametes sp. in enzymatic aggregates known as CLEAs (cross-linked Enzymatic Aggregates). The laccase activity was colorimetrically determined by using ABTS and DMP as substrates. In addition, the CLEAs’ decolorization activity was spectrophotometrically evaluated. The results showed that the greater laccase activity of CLEAs was obtained by using isopropanol and 25 mM glutaraldehyde as precipitating agents. Furthermore, CLEAs were able to decolorize different textile dyes even during successive cycles. The present study demonstrates that CLEAs with laccase activity could serve as catalysts agents for the treatment of textile dyes

Power-Integrated Circuit Active Leakage Current Detector

Most of the failures of induction motors become insulation faults, causing a permanent damage. Using differential current transformers, a system capable of insulation fault detection was developed, based on the differential relay protection scheme. Both signal injection and fault detection circuitry were integrated in a single chip. The proposed scheme is faster than other existing protection and not restricted to protect induction motors, but several other devices (such as IGBTs) and systems. This paper explains the principle of operation of fault protection scheme and analyzes an integrated implementation through simulations and experimental results. A power-integrated circuit (PIC) implementation is presented

Methodology and Results of the Reliawind Reliability Field Study

The EU FP7 Reliawind project has the aim to identify and understand critical failures and their mechanisms through quantitative studies of detailed wind farm data. A common wind turbine taxonomy and a universal database structure for storing downtime events from multiple manufacturer's turbines have been defined. Systematic and consistent processes have been developed to deal with historical data from wind farm Owners and Operators. Data including 10-minute SCADA, service records/work orders and alarm logs have been analysed to determine downtime events within the common taxonomy. The downtime events have been analysed to determine the distribution of failure rates and downtimes between the sub-assemblies. To date 31,500 downtime events have already been added to the common database structure and the database is still expanding

Prevalencia de enfermedades hepáticas en una población rural de alta montaña: estudio clínico, bioquímico y ecográfico

En este estudio clínico, bioquímico y ecográfico se evaluó la prevalencia de hepatopatías en Lara, una comunidad rural aislada de alta montaña en Tucumán, provincia con la máxima prevalencia de infección por HAV en niños de Argentina. Lara carece de agua potable, electricidad y cloacas. Se estudiaron 102 habitantes, lo que representa el 41% de la población. El anti-HBc y anti-HCV fueron negativos en todos los casos. Ningún niño presentó anormalidades hepáticas. El 41% de los adultos refirió ingesta alcohólica y el 12% transfusiones. Se observó incremento leve de ALT en 3 casos (6%). La ecografía demostró esteatosis en 8 individuos (16%), litiasis vesicular en 7 (14%), microcalcificaciones en 5 (10%) y quistes de aspecto parasitario en 4 (8%). La prevalencia de infección por HAV en Lara fue de 89% en adultos y 35% en niños, siendo significativamente menor que la de los niños de la ciudad de Tucumán con nivel socioeconómico medio / alto (53%, p = 0.05) o bajo (74%, p = 0.0006). La diferencia fue más evidente en niños menores de 5 años (0%, 53% y 75% respectivamente). La serología para hidatidosis fue positiva en 3/4 individuos con quistes, 2/5 con microcalcificaciones y 17/85 (20%) con ecografía normal, lo que sugiere que la técnica de Elisa utilizada se asocia a frecuentes resultados falsos positivos. El estudio poblacional de Lara demostró una elevada prevalencia de esteatosis, litiasis vesicular e hidatidosis en adultos, ausencia de infección por HBV y HCV, y una baja exposición al HAV en niños, especialmente en menores de 5 años