Search results for "Energy engineering"
showing 10 items of 1099 documents
Performance study of a Helical Savonius hydrokinetic turbine with a new deflector system design
2019
Abstract The use of renewable energy sources has becoming a necessity to generate electricity. Helical Savonius rotors have been preferred for small-scale hydropower generation. Numerous studies were carried out to improve the performance of the Helical Savonius rotor which has not been fully explored. In this paper, an experimental study was carried out to evaluate the performance of a Helical Savonius water rotor in an irrigation channel. In order to enhance the performance of the studied water rotor, a new deflector system design was proposed. Different configurations of the proposed deflector system were tested numerically using the commercial software ANSYS FLUENT 17.0. Without a defle…
Mutations in Romanian Agriculture after De-Collectivization and Privatization
2013
Abstract This paper aims at presenting mutations in agriculture occurred in the process of collectivization and privatization of it. In this paper we analyze the period 1990-2010 following: the dynamics of the use of the land by ownership, the dynamic structure of the value of agricultural production, the dynamic structure of the value of agricultural production and development park tractors and machinery on-farm ownership. In the analyzed period is shown that mutations that occurred in the ownership of the land and other means of production and the system of relations between agriculture and other sectors of the economy have influenced the evolution of the structure of agricultural product…
Cognitive Translation and Interpreting Studies (CTIS)
2021
Factores asociados a los accidentes de motocicleta en Barcelona, España
2019
espanolResumen: Este estudio analizo los accidentes de motocicleta y ciclomotor en Barcelona (Espana). 53.190 informes de conductores de motocicleta y ciclomotor involucrados en accidentes entre los anos 2006 y 2011 fueron extraidos de la base de datos de accidentes con victimas de la Direccion General de Trafico. Estos datos fueron analizados en terminos de sexo, grupos de edad, motivo del desplazamiento, dia de la semana, infracciones de velocidad, uso del casco y lesividad, con el objetivo de estudiar las caracteristicas de los accidentes de motocicleta y ciclomotor en Barcelona y evaluar las diferencias entre conductores varones y mujeres en estos accidentes. La gravedad de los accident…
Determination of Students’ Satisfaction Regarding Extracurricular Activities Conducted in The University. Comparative Study Romania-Germany
2014
Abstract The goal of this paper is to determine students’ satisfaction related to extracurricular activities in the field of vocational training, to identify possible problems and potential improvements. The research was conducted using quantitative and qualitative research methodology, various secondary sources, and the data were collected through the questionnaire method. The study constitutes the base of a compared management research Romania-Germany. Questioned have been 120 students from northern Germany, University of Applied Sciences Flensburg, University of Applied Sciences: Technology, Business and Design Wismar and University of Applied Sciences Kiel and 146 students from the cent…
High frequency resistivity in La2-xSrxCu1-yCoyO4 ceramics
2019
Resitivity measurements have been performed in La:Sr:Cu:Co:O ceramics in a frequency range from 5Hz – 10 9 Hz. A strongly frequency dependent resistance has been observed in La 2 CUO 4 which we interpret in terms of a smooth dielectric to metal transition due to localization effects.
Comparison between the energy performance of a ground coupled water to water heat pump system and an air to water heat pump system for heating and co…
2008
Abstract The investigation presented in this article was aimed at demonstrating the technical and economical feasibility of using ground source heat pump systems in mixed climate applications, where cooling requirements are dominant. We show an experimental comparison between a ground coupled heat pump system and a conventional air to water heat pump system, focussing at the heating and cooling energy performance. A direct comparison could be made as both systems are linked, in parallel, to the same building with exactly the same loads and climatic conditions. For a whole climatic season the results obtained show that the geothermal system saves, in terms of primary energy consumption, a 43…
ICT applications for improving the generation and distribution efficiency of a small mediterranean island
2016
The paper presents a study on the opportunities offered by ICT for improving the efficiency of the generation and distribution system of a small island. The island taken into consideration is the Italian Lampedusa island. In the paper, the power distribution system of the island is described and the summer and winter daily load profiles are examined in order to define the more suitable control actions for improving the generation and distribution efficiency of the power system. Finally the architecture of an idoneous control system for the smart grid is proposed and an evaluation of the purchase and installation costs of components and devices for the transition of a traditional house towar…
Mineral and trace element composition of the Lokpanta oil shales in the Lower Benue Trough, Nigeria
2011
Abstract The concentrations of minerals and trace elements in the Lokpanta oil shale from the Lower Benue Trough, Nigeria have been determined by X-ray diffraction (XRD) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), respectively. X-ray diffraction data were evaluated using the SIROQUANT™ interactive data processing system based on Rietveld interpretation methods. A new method of trace element determination in oil shale, involving LA-ICP-MS analysis of glass beads prepared by fusing oil shale ash on an iridium strip heater was used, and the accuracy of the method was assessed by including a standard shale reference material (SGR-1b) in the analysis program. The…
Recursive Selective Harmonic Elimination for Multilevel Inverters: Mathematical Formulation and Experimental Validation
2023
A recursive method that eliminates +1 harmonics and their respective multiples from the output voltage of a cascaded H-bridge multilevel inverters with = 2 dc sources ( = 1, 2, 3,...) is proposed. It solves 2×2 linear systems with not singular matrices and always gives an exact solution with very low computational effort. Simulated results in three-phase five, nine, seventeen and thirty three level CHB inverters, and experimental results in five-level inverter demonstrate the validity of the method.