690 research outputs found

    Fuzzy Inference System for VOLT/VAR control in distribution substations in isolated power systems

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    This paper presents a fuzzy inference system for voltage/reactive power control in distribution substations. The purpose is go forward to automation distribution and its implementation in isolated power systems where control capabilities are limited and it is common using the same applications as in continental power systems. This means that lot of functionalities do not apply and computational burden generates high response times. A fuzzy controller, with logic guidelines embedded based upon heuristic rules resulting from operators at dispatch control center past experience, has been designed. Working as an on-line tool, it has been tested under real conditions and it has managed the operation during a whole day in a distribution substation. Within the limits of control capabilities of the system, the controller maintained successfully an acceptable voltage profile, power factor values over 0,98 and it has ostensibly improved the performance given by an optimal power flow based automation system

    Radio-Optically- and Thermally Stimulated Luminescence of Zn(BO2)2:Tb3+ exposed to Ionizing Radiation

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    The optical absorption of zinc tetraborate at different concentrations of the terbium impurity (0, 0.5, 1, 2, 4, 8 mol%) was analyzed. The radioluminescence (RL) emission spectra was obtained after beta irradiation of a 90Sr/90Y source. The RL spectrum showed the characteristics bands of Tb3+ with two main emissions at 489 nm and 546 nm which corresponding to the5D4→7F6 and 5D4→7F5 transitions respectively in this ion. The OSL and TL characteristics have been analyzed. The stimulation blue light (497 nm) of a diode laser at 500 mA was used to bleach the thermoluminescent (TL) signals obtained with 5Gy of 60Co source. The two main glow peaks (79 and 161 °C) are sensitives under 497 nm stimulation, and they were shifted to higher temperature values and faded their TL intensities. Similar behavior of TL glow curves before and after OSL stimulation with blue light was observed when the samples were exposed to 30 Gy gamma dose of 137Cs irradiator. The OSL signal response was linear with the dose range of 1-10 Gy and increased their response up to 200 Gy gamma dose. The OSL shows a bleaching sensitive shallow traps and diminishing the intensity of the TL glow curves remaining a complex traps distribution. The RL, TL and OSL properties were investigated in Zn(BO2)2:Tb3+ phosphor

    Analysis of S. pombe SIN protein association to the SPB reveals two genetically separable states of the SIN.

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    The Schizosaccharomyces pombe septation initiation network (SIN) regulates cytokinesis, and asymmetric association of SIN proteins with the mitotic spindle pole bodies (SPBs) is important for its regulation. Here, we have used semi-automated image analysis to study SIN proteins in large numbers of wild-type and mutant cells. Our principal conclusions are: first, that the association of Cdc7p with the SPBs in early mitosis is frequently asymmetric, with a bias in favour of the new SPB; second, that the early association of Cdc7p-GFP to the SPB depends on Plo1p but not Spg1p, and is unaffected by mutations that influence its asymmetry in anaphase; third, that Cdc7p asymmetry in anaphase B is delayed by Pom1p and by activation of the spindle assembly checkpoint, and is promoted by Rad24p; and fourth, that the length of the spindle, expressed as a fraction of the length of the cell, at which Cdc7p becomes asymmetric is similar in cells dividing at different sizes. These data reveal that multiple regulatory mechanisms control the SIN in mitosis and lead us to propose a two-state model to describe the SIN

    Costos y viabilidad económica de la producción y comercialización de la conserva de trucha (Oncorhynchus mykiss) en escabeche

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    Puno is the first rainbow trout producing region in Peru. The objective of the study was to study the feasibility of giving added value to trout. The cost analysis and financial viability of the production of six types of canned pickled trout preserves were considered. The fillets were obtained from trout fed with three commercial foods (Salmofood®, Naltech® and Tomasino®) and the preserves had two presentations (can vs. glass). The production costs were calculated through a documented record of data at market prices. The general theory of production costs was applied and through the cash flow financial tool the profitability indicators were found. The financial net present value (NPVf) was positive for all six presentations. The internal rate of return (IRR), both for canning (34.5, 37.5 and 42.8%) and for glass canning (34.7, 38.2 and 44.3%) was higher than the opportunity cost of capital (COK) and in both cases, the benefit-cost ratio (B/C) was similar and greater than one (1.05, 1.06 and 1.07) for the three commercial foods, respectively. The capital recovery period was between 5 and 6 years for the two types of preserves. In conclusion, the pickled trout canning project is profitable and, therefore, its investment is recommended to contribute to the sustainability of production and improve the income of producers in the region.Puno es la primera región productora de truchas arcoíris en el Perú. El estudio tuvo como objetivo estudiar la factibilidad de dar valor agregado a la trucha. Se consideró el análisis de costos y la viabilidad financiera de la producción de seis tipos de conservas de trucha en escabeche. Los filetes fueron obtenidos de truchas alimentadas con tres alimentos comerciales (Salmofood®, Naltech® y Tomasino®) y las conservas tuvieron dos presentaciones (lata vs. vidrio). Los costos de producción se calcularon mediante un registro documentado de datos a precios de mercado. Se aplicó la teoría general de costos de producción y mediante la herramienta financiera de flujo de caja se hallaron los indicadores de rentabilidad. El valor actual neto financiero (VANf) fue positivo para las seis presentaciones. La tasa interna de retorno (TIR), tanto para la conserva de lata (34.5, 37.5 y 42.8%) como para la conserva en vidrio (34.7, 38.2 y 44.3%) fue mayor al costo de oportunidad del capital (COK) y en ambos casos la ratio beneficio-costo (B/C) fue similar y mayor a uno (1.05, 1.06 y 1.07) para los tres alimentos comerciales, respectivamente. El periodo de recuperación del capital estuvo entre 5 y 6 años para los dos tipos de conservas. En conclusión, el proyecto de elaboración de conservas de trucha en escabeche es rentable y, por tanto, es recomendable su inversión para contribuir con la sostenibilidad de la producción y mejorar los ingresos de los productores de la región

    Respuesta productiva de truchas arcoíris (Oncorhynchus mykiss) al régimen alimenticio con alimentos comerciales bajo condiciones de crianza intensiva en el Lago Titicaca

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    The aim of this study was to determine the effect of two feeding regimes (7 vs 6 d) and three commercial foods (TO= Tomasino®, NA= Naltech® and SA= Salmofood®) on the productive-commercial performance and organ development. of rainbow trout in the fattening phase under conditions of Lake Titicaca, Peru. A total of 1080 trout of 185 g live weight (LW), 26.5 cm total length (TL) and 1.00 body condition index (BCI) were randomly placed in 36 1.2x1.2x1.6 m nylon cages (30 trout/cage). The control of productive parameters (LW, TL and feed consumption) was carried out at 30, 60 and 90 d. The BCI, the mean daily feed intake (DFI), the mean daily weight gain (DWG) and the feed conversion ratio (FCR) were determined. The carcass yield (CY), fillet yield (FY), pigmentation (MP) and the relative weight of the organs were determined at 215 d. The feeding regime did not affect the LW, TL and BCI, but the 7-d feeding had a better FCR (1.12 vs 1.25; p<0.001). Feeding with TO and NA produced lower DFI (3.7, 4.0 and 4.3 g/d; p<0.001), lower DWG (2.9, 3.3 and 4.1 g/d; p<0.001) and worse FCR (1.27, 1.21 and 1.07; p<0.001) with respect to SA at 90 d, respectively. The CY, FY and MP were not affected, but the relative weights of the liver and heart were influenced by feed. It is concluded that the 7-d diet improved feed conversion and pigmentation, while commercial feeds influenced productive performance, pigmentation and relative weight of organs, but not carcass and fillet yield of trout.El objetivo del estudio fue determinar el efecto de dos regímenes de alimentación (7 vs 6 d) y de tres alimentos comerciales (TO= Tomasino®, NA= Naltech® y SA= Salmofood®) sobre el rendimiento productivo-comercial y desarrollo de órganos de truchas arcoíris en la fase de engorde en condiciones de lago Titicaca, Perú. Un total de 1080 truchas de 185 g de peso vivo (PV), 26.5 cm longitud total (LT) y 1.00 de índice de condición corporal (ICC) fueron colocadas al azar en 36 jaulas de nylon de 1.2x1.2x1.6 m (30 truchas/jaula). El control de parámetros productivos (PV, LT y consumo de alimento) fue realizado a los 30, 60 y 90 d. Se determinó el ICC, el consumo medio diario de alimento (CMD), la ganancia media diaria de peso (GMD) y el índice de conversión alimenticia (ICA). El rendimiento de canal (RC), de filete (RF), la pigmentación (PF) y el peso relativo de los órganos se determinó a los 215 d. El régimen alimenticio no afectó el PV, LT y ICC, pero la alimentación de 7 d tuvo mejor ICA (1.12 vs 1.25; p<0.001). La alimentación con TO y NA produjeron menor CMD (3.7, 4.0 y 4.3 g/d; p<0.001), menor GMD (2.9, 3.3 y 4.1 g/d; p<0.001) y peor ICA (1.27, 1.21 y 1.07; p<0.001) respecto a SA a los 90 d, respectivamente. El RC, RF y PF no fueron afectados, pero el peso relativo del hígado y corazón fue influenciado por los alimentos. Se concluye, que el régimen alimenticio de 7 d mejoró la conversión alimenticia y la pigmentación, en tanto que los alimentos comerciales influyeron en el rendimiento productivo, la pigmentación y en el peso relativo de los órganos, pero no en el rendimiento de canal y filete de las truchas

    Effect of Dopant Ions on the Electrical Conductivity and Microstructure of Polyaniline (Emeraldine Salt)

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    Samples of polyaniline (emeraldine salt) were prepared with different protonic acid dopants, namely, hydrochloric acid (HCl), nitric acid (HNO3), perchloric acid (HClO4), sulfuric acid (H2SO4), and hydroiodic acid (HI). Using the two-point probe method, it was found that the samples had ohmic behaviors in which high linear coefficients were found in the range 0.9686–0.9997. On the other hand, the electrical conductivities were measured using the Van der Pauw method. The undoped sample had a conductivity of 5x10–4 S/cm. The highest conductivity of 109.04 S/cm was observed for the HClO4-doped sample, while the lowest value (0.02 S/cm) was obtained for the HI-doped sample. These conductivities were compared with the computed energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) where it was found that they are inversely proportional to each other. Scanning electron microscopy revealed significant differences among the samples in terms of shapes and morphologies

    Aggressive Behavior in School-aged Children: Clusters based on Anger, Empathy and Testosterone and Cortisol Measures

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    The aim of this piece of research was to study the existence of clusters based on anger, empathy and cortisol and testosterone measures associated with aggressive behavior in school-aged children. The sample group comprised 139 eight-year-old children (80 boys and 59 girls). Aggressive behavior was measured using the Direct and Indirect Aggression Scale. Both psychological and biological variables were used to determine psychobiological profiles. The psychological variables considered were trait anger, measured using the State-Trait Anger Expression Inventory for Children and Adolescents, and empathy, measured using the Empathy Quotient-Child Version. Testosterone and cortisol concentrations were measured through saliva samples and analyzed using an ELISA (Enzyme-linked immunosorbent assay). A Cluster Analysis revealed three clusters which were clearly different as regards their psychological and biological characteristics. The analysis of variance (ANOVA) revealed that the cluster characterized by having higher anger levels, lower empathy levels and higher testosterone and cortisol levels was more aggressive than the other two (p < .0001, η2 = .19). The results indicate that studying psychological and biological variables together may help establish differentiated aggression patterns among children

    Prevalence of intestinal parasites in children and domestic animals from two peri-urban neighborhoods in northeastern Argentina

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    This study aimed to examine the prevalence of intestinal parasites in children and domestic animals from two peri-urban neighborhoods in Corrientes, Argentina. We also evaluated the characteristics of humans, socio-environmental features, and hygiene practices associated with the presence of parasites. Fecal samples were examined using techniques of concentration by sedimentation and flotation. The Graham method was used to diagnose Enterobius vermicularis eggs in children. We carried out the univariate and bivariate analysis of the data. We analyzed 58 dwellings, from which we obtained 146 stool samples from children and 101 from animals. We found at least one parasite species in 54 dwellings (93.1%). We found that 52.7% of children had parasites, mainly Blastocystis spp. (35.6%) and Giardia spp. (21.2%). We found that 67.32% of the animals had parasites, the most prevalent species being hookworms (60.7%). In conclusion, it is evident that the domestic environment can favor the transmission of these parasites
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