Search results for "Energy engineering"
showing 10 items of 1099 documents
Power Line Communication in Medium Voltage Systems: Characterization of MV Cables
2008
The aim of this paper is to illustrate the development of a theoretical and experimental study on the characterization of medium voltage (MV) cables in the frequency range 25-200 kHz. Two transmission line configurations, line-ground and line-line, were considered in order to evaluate the main parameters, such as the characteristic impedance and the attenuation constant alpha. A simplified model of the line-ground configuration is proposed which allows one to evaluate the characteristic impedance and the attenuation constant by means of geometrical dimensions. The model was verified by experimental measurements on commonly used MV cables, RG7H1R, with an aluminium core of different sections…
Validation of a Work Engagement Scale. Profi les associated with high Performance and Job Satisfaction
2017
El objetivo principal de este estudio consistía en la validación de una escala para la evaluación del work engagement -compromiso con el trabajo-, considerado como una presencia psicológica en el rol que incluye atención, absorción y energía dirigida a tareas laborales. Mediante análisis factorial confirmatorio, estimación de la consistencia interna y evidencias de validez convergente y discriminante, se confirma que la Escala Argentina de Compromiso con el Trabajo es una prueba válida y confiable para su uso en población argentina. Además, se buscó analizar si existen diferencias en los niveles de work engagement de acuerdo con variables individuales y organizacionales. Se observaron mayor…
Intellectual Property Rights: An Economic Approach
2014
Abstract This paper aims to analyse the intellectual property rights from an economic perspective. The paper is discussing the points of view of well known economists in relation to the positive and negative impacts of the intellectual property systems. It brings also into discussion the role of IPR as a barrier to entry and a mean to restrict competition and to favour monopoly situations.
Analysis of multiple intelligences and creativity in university students
2018
espanolResumen: Un reto de la educacion actual es formar a alumnos competentes para desenvolverse en una sociedad diversa y dinamica. El cociente intelectual no es suficiente para garantizar el exito academico ni profesional (Extremera & Fernandez-Berrocal, 2006) y deben considerarse aspectos cognitivos, sociales y emocionales. El objetivo del estudio fue analizar el grado alcanzado en estudiantes universitarios de trabajo social en las inteligencias multiples, inteligencia emocional, creatividad y rendimiento academico, asi como su relacion y las diferencias en funcion del sexo y el curso en una muestra de 100 estudiantes. Se encontraron diferencias significativas en funcion del curso y re…
Husk Energy Supply Systems for Sunflower Oil Mills
2020
Together with solar, wind, and hydro renewable energy sources (RES), biomass constitutes an integral part of the high-renewables electricity systems. Considerable feedstocks for electricity generation are process-based residues. Ukraine is the world leader in sunflower seed production, therefore, husk (a by-product of oil production) is a promising biofuel for combustion- based power plants. The plants consume primarily electricity and fossil fuels (natural gas or fuel oil) for steam production. Their usage affects the edible oil production cost and impacts on climate change. The above facts force us to look for alternatives. By-product (husk) utilization can reduce exhaustible energy consu…
Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults
2023
The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…
Imagem corporal positiva e redes sociais na população adulta da área metropolitana de Buenos Aires
2021
Resumen: La imagen corporal positiva presenta una función protectora preeminente ante los medios de comunicación actuales, sin embargo, a la fecha no se cuenta con estudios que la vinculen con las redes sociales. El objetivo de este trabajo fue estudiar la asociación entre la motivación y usos de redes sociales y la imagen corporal positiva, considerando diferencias por sexo y grupos de edad. La muestra contó con 180 participantes, 94 varones (52.2 %) y 86 mujeres (47.8 %), edades de 18 a 65 años (M = 31.03; DE = 13.34). Los instrumentos utilizados fueron el BAS-2 y una encuesta sobre redes sociales. La imagen corporal positiva presentó asociación negativa con dos escalas de la motivación p…
The Industrial Applicability of PEA Space Charge Measurements, for Performance Optimization of HVDC Power Cables
2019
Cable manufacturing industries are constantly trying to improve the electrical performance of power cables. During the years, it was found that one of the most relevant degradation factors influencing the cable lifetime is the presence of space charge in the insulation layer. To detect the accumulated charge, the pulsed electro-acoustic (PEA) method is the most used technique. Despite the wide use of the PEA cell, several issues are still present. In particular, the PEA output signal is strongly disturbed by the acoustic waves reflections within the PEA cell. This causes the distortion of the output signal and therefore the misinterpretation of the charge profiles. This, in turn, may result…
Spatial Succession for Degradation of Solid Multicomponent Food Waste and Purification of Toxic Leachate with the Obtaining of Biohydrogen and Biomet…
2022
A huge amount of organic waste is generated annually around the globe. The main sources of solid and liquid organic waste are municipalities and canning and food industries. Most of it is disposed of in an environmentally unfriendly way since none of the modern recycling technologies can cope with such immense volumes of waste. Microbiological and biotechnological approaches are extremely promising for solving this environmental problem. Moreover, organic waste can serve as the substrate to obtain alternative energy, such as biohydrogen (H2) and biomethane (CH4). This work aimed to design and test new technology for the degradation of food waste, coupled with biohydrogen and biomethane prod…
Towards controlling PCDD/F production in a multi-fuel fired BFB boiler using two sulfur addition strategies
2014
Abstract PCDD/F abatement strategies – sulfur pellet addition and peat co-combustion – were tested for a BFB boiler facility utilizing SRF-bark-sludge as fuel. In this paper chemical and physical analyses of electrostatic precipitator (ESP) fly ashes were used to explain the differences in the performance of these strategies. These analyses revealed a difference between the coarse and fine fly ashes collected in the ESP. Chemical analysis of the fine fly ashes revealed high concentration of easily volatilized elements while the SEM micrographs showed that fine ash are composed of clusters of spherical particles, thereby leading to a conclusion that fine ashes were originally in a gas phase …