Evaluacion de distintos metodos para estimar la temperatura de operacion de modulos fotovoltaicos y estimacion de las perdidas de energia por efecto de la temperatura

Debido a la incidencia de la temperatura de un panel fotovoltaico en su rendimiento energético, se compararon distintos modelos matemáticos que predicen en forma aceptable la temperatura final de un panel en función de las variables climáticas. Para ello se utilizaron los datos experimentales de una instalación fotovoltaica ubicada en la ciudad de Rosario, aplicando cinco modelos conocidos y evaluando cuál es el que mejor ajusta los valores reales medidos. Una vez elegido el modelo más adecuado, se hizo el cálculo de temperatura de operación de un panel en distintos puntos de la Provincia de Santa Fe para los cuales se cuenta con datos provenientes de la Red Solarimétrica. Se calcularon las energías teóricas generadas para condiciones estándar de temperatura, y las pérdidas de energía por efecto de la temperatura real de operación de los paneles.Fil: Battioni, Mario Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Risso, Gustavo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Cutrera, Miriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Schmidt, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentin

PENGARUH FINANCIAL DISTRESS, LEVERAGE, KESEMPATAN BERTUMBUH, DAN PERTUMBUHAN PERUSAHAAN TERHADAP KONSERVATISME AKUNTANSI PADA PERUSAHAAN MANUFAKTUR YANG TERDAFTAR DI BURSA EFEK INDONESIA TAHUN 2012-2014

The objectives of this research are to examine (1) the effect of financial distress, leverage, growth opportunities, and company growth simultaneously on accounting conservatism, and (2) the effect of financial distress, leverage, growth opportunities, and company growth partially on accounting conservatism.Purposive sampling method is used in this research to determine the sample. The sample of this research is manufacturing company sub-sector consumption listed in Indonesia Stock Exchange during 2012 until 2014. The analysis method used in the research is multiple linear regressions.The result of this research are (1) financial distress, leverage, growth opportunities, and company growth simultaneously effect the accounting conservatism, (2) financial distress, leverage, and company growth partially have not effect the accounting conservatism and, (3) growth opportunity have an effect on the accounting conservatismKeywords: accounting conservatism, financial distress, leverage, growth opportunities, and company growthBanda Ace

Calefaccion solar de una piscina a muy bajo costo

Se propuso el diseño de un dispositivo que funcione como calefactor solar térmico para una piscina hogareña, utilizando para tal motivo una cubierta de chapa de un techo ya existente. Se fijó como consigna que la temperatura del agua en la pileta debía aumentar a razón de un grado centígrado por hora (idéntico comportamiento al de una caldera comercial para uso en piscinas), en la franja horaria de 11 a 16 horas, durante el período de octubre a marzo. A modo de prototipo, se fabricó un dispositivo similar al propuesto, pero en una superficie que representaba el 5,8% del área disponible. Se midieron los valores de temperatura del agua a la entrada, salida e intermedio, la temperatura ambiente y la radiación. En base a los cálculos de calor requerido, se comprobó que el dispositivo propuesto cumple con la consigna planteada.Fil: Risso, Gustavo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Cutrera, Miriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Battioni, Mario Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Schmidt, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Lara, Miguel Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentin

Effect of fish oil and vitamin E on sperm lipid peroxidation in dogs

The objective was to evaluate the effects of dietary fish oil (FO) and vitamin E (VE) supplementation on sperm sensitivity to lipid peroxidation (LP) in dogs. Using an incomplete replicate 3 × 3 Latin square design, five dogs were allocated into three groups. One of the squares was incomplete and had two dogs that were used with three treatments. The dogs were assigned to three different treatments, fed a control diet of balanced commercial food (control group; CG), control diet supplemented with 54 mg FO/kg body weight0·75 per d (FO group; FG) and FO plus 400 mg VE per d (FO and VE group; FEG) for 60 d. Semen samples were collected on days 0 and 60 and divided into two halves, peroxidised and control, with or without ascorbate–Fe2+, respectively. LP was measured in both halves by chemiluminescence as counts per min/mg protein. Fatty acid profile was determined by GC. Data were analysed using the mixed procedure (SAS). On day 0, LP increased in all groups in the peroxidised samples (P 0·1). Additionally, on day 60 total n-3 was higher in the FG and FEG compared with the CG (P < 0·05). Supplementation with FO alone or together with VE decreased LP in peroxidised samples. These results could indicate a protective effect of n-3 on sperm. More studies are needed to understand the mechanism whereby FO and/or FO plus VE decrease LP in dogs’ sperm.Facultad de Ciencias VeterinariasInstituto de Genética Veterinari

Thermodynamic simulation of a multi-step externally fired gas turbine powered by biomass

[EN]A thermodynamic model for a realistic Brayton cycle, working as an ex- ternally red gas turbine fueled with biomass is presented. The use of an external combustion chamber, allows to burn dirty fuels to preheat pure air, which is the working uid for the turbine. It also avoids direct contact of ashes with the turbine blades, resulting in a higher life cycle for the turbine. The model incorporates a high temperature heat exchanger and an arbitrary number of turbines and compressors, with the corresponding number of in- tercoolers and reheaters. It considers irreversibilities such as non-isentropic compressions and expansions, and pressure losses in heat input and release. The composition and temperature of the combustion gases, as well as the variable ow rate of air and combustion gases, are calculated for speci c biomasses. The numerical model for a single stage con guration has been validated by comparing its predictions with the data sheets of two commer- cial turbines. Results are in good agreement. Curves on the dependence of thermal e ciency and power output with the overall pressure ratio will be shown for several plant con gurations with variable number of compres- sion/expansion stages. Also the in uence of di erent types of biomasses and their moisture will be analyzed on parameters such as fuel consumption and exhaust gases temperature

Thermodynamic Simulation of a Hybrid Thermo-Solar Externally Fired Gas Turbine Power Plant Fueled with Biomass

[EN]A thermodynamic model for a hybrid thermo-solar externally fired gas turbine power plant fueled with biomass is presented. This technology represents a fully renewable way of obtaining electric power relying mainly in biomass with an extra advantage of decreasing its consumption at good radiative conditions. A concentrated solar power plant is implemented considering the Solugas project situated in Abengoa’s Solúcar Platform near Seville. To predict its behavior two models were implemented and compared with experimental data. Typical daily evolution of the output power, biomass mass flow, overall efficiency and biomass conversion efficiency for a typical Uruguayan year is presented. In addition, global results are presented leading to a 1.5% biomass saving increasing the economic efficiency a 0.34% what denotes the solar field and thermal power of receiver seem to be undersized

Dissociation between sublingual and gut microcirculation in the response to a fluid challenge in postoperative patients with abdominal sepsis

Results: Fluid administration increased the cardiac index (2.6 ± 0.5 vs. 3.3 ± 1.0 L/min/m2, P < 0.01) and mean arterial blood pressure (68 ± 11 vs. 82 ± 12 mm Hg, P < 0.0001). The sublingual but not the intestinal red blood cell (RBC) velocity increased (912 ± 270 vs. 1,064 ± 200 μm/s, P < 0.002 and 679 ± 379 vs. 747 ± 419 μm/s, P = 0.12, respectively). The sublingual and intestinal perfused vascular density (PVD) did not change significantly (15.2 ± 2.9 vs. 16.1 ± 1.2 mm/mm2 and 12.3 ± 6.7 vs. 13.0 ± 6.7 mm/mm2). We found no correlation between the basal sublingual and intestinal RBC velocities or between their changes in response to the fluid challenge. The individual changes in sublingual RBC velocity correlated with those in cardiac index and basal RBC velocity. Individual changes in intestinal RBC velocity did not correlate with either the cardiac index modifications or the basal RBC velocity. The same pattern was observed with the sublingual and the intestinal PVDs. The sublingual RBC velocities and PVDs were similar between survivors and nonsurvivors. But the intestinal RBC velocities and PVDs were lower in nonsurvivors.Conclusions: In this series of postoperative septic patients, we found a dissociation between sublingual and intestinal microcirculation. The improvement in the sublingual microcirculation after fluid challenge was dependent on the basal state and the increase in cardiac output. In contrast, the intestinal microcirculation behaved as an isolated territory.Methods: Twenty-two septic patients in the first postoperative day of an intestinal surgery, in which an ostomy had been constructed, were evaluated both before and 20 min after a challenge of 10 mL/kg of 6% hydroxyethylstarch 130/0.4. We measured systemic hemodynamics and sublingual and intestinal microcirculation. Correlations between variables were determined through the Pearson test.Background: This study was performed to compare intestinal and sublingual microcirculation and their response to a fluid challenge.Facultad de Ciencias Médica

Cuerpo, Saber y Educación Física : Una lectura de los discursos en torno a la educación física desde la prueba de ingreso

Esta trabajo se enmarca dentro de la línea de investigación "Cuerpo- Educación y Enseñanza" del Grupo de Políticas Educativas y Políticas de Investigación en Educación Física, ISEF- UdelaR. Aprobado y financiado por el Programa de Apoyo a la Investigación Estudiantil de la CSIC- UdelaR. Desde su conformación el ISEF ha tenido restricciones a la hora de permitir el ingreso como estudiante, estás mismas han ido mutando en el devenir de la historia. En este marco la investigación se plantea la siguiente pregunta: ¿En qué medida los cambios que han sufrido las propuestas de examen de ingreso desde su implementación, han sido influenciados por los discursos relativos a la concepción de la Educación Física del momento? Nos proponemos indagar sobre las posibles relaciones y conexiones entre los cambios que ha tenido la prueba de ingreso, en la licenciatura en Educación Física del ISEF, y los discursos relativos a la concepción de Educación Física, buscando establecer relaciones entre los discursos que se configuraron hegemónicos dentro del campo y los dispositivos constitutivos de la prueba de ingreso. Nuestro marco conceptual estará centrado, básicamente, sobre dos supuestos; la consideración de que "El cuerpo es una construcción simbólica, no una realidad en sí mismo" (Le Breton, 1995) y el segundo supuesto que trabajaremos para el abordaje del problema es el aportado por Foucault en relación a la construcción del cuerpo moderno "Como objeto y blanco de poder" (Foucault, 1975).Departamento de Educación Físic

Pumped heat energy storage with liquid media: Thermodynamic assessment by a Brayton-like model

[EN]A thermodynamic model for a steady state pumped heat energy storage in liquid media is presented: it comprises a coupled Brayton-like heat pump and heat engine cycles connected to a cryogenic liquid and a hot molten salt by counter-flow heat exchangers. The model considers non-isothermal heat transfers between the working fluid and the liquid media and explicitly includes a set of parameters accounting for the main internal and external losses, heat leak, and pinch point effects for both the heat pump (charge) and heat engine (discharge) modes. Specific expressions for the main magnitudes in the charge (as the input power and coefficient of performance) and discharge (as power output and efficiency) modes and the global round trip efficiency have been analytically derived in terms of isentropic efficiencies of the compressor and turbine, pressure losses in the heat exchange processes, effectivenesses of the external counter-flow heat exchangers, and coupling between the working fluid and the storage and cryogenic liquid media. Round trip efficiencies around of 35 − 40% have been obtained, internal losses being those with main negative influence on the calculated values. The strong constraints imposed by the pinch point effects and liquid media have been analyzed. The model provides a thermodynamic assessment of the main involved processes and their interplay for a selected arrangement (molten salts, cryogenic fluid, and the charge and discharge power blocks) in order to check parametric strategies for thermodynamic optimization and design. These strategies are based on a reduced set of parameters of the overall installation and without the high computational costs of dynamical models.(ANII); Fondo Sectorial de Energía, Uruguay; contract FSE-1-2018-1-153077

Multicriteria optimization of Brayton-like pumped thermal electricity storage with liquid media

[EN]A multi-objective and multi-parametric optimization of a Pumped Thermal Electricity Storage system based on Brayton cycles is presented by the calculation of different Pareto fronts and the associated Pareto optimal sets for energetic and design analysis, respectively. A large range of internal and external irreversibilities and the thermodynamic properties of the storage media are taken into account. The analysis shows that the heat capacity of the working fluid and the heat capacity of the storage media should be the same in the contact with the hot reservoirs and in the contact with the cold reservoir in the heat pump, but in the contact with the cold reservoir for the heat engine the ratio should be 0.33, this offers information regarding the mass flow increasing significantly the achievable values for the round-trip efficiency, power output and the heat engine efficiency in the discharge process. Optimal values are given in terms of the degree of irreversibilities in the system and a comparison is made with extreme cases of infinite and minimum sizes for the storage system. Round-trip efficiencies in the so-called optimum scale/mass-flow-ratio design point exhibits noticeably larger values compared to previously reported results including the so-called endoreversible limit, where no internal irreversibilities are considered and where the improvement can achieve 49% over the endoreversible case in the most ideal scenario. Explicit numerical values of the maximum round trip efficiency, power output, and efficiency are given for a broad range of both internal and external irreversibilities.Agencia Nacional de Investigación e Innovación (ANII): Fondo Sectorial de Energía (Uruguay), under contract FSE-1-2018-1-153077 Universidad de Salamanca, Spain, under contracts 18.KB.YF/463A.C.01 and 0218463AB01