Search results for "Energy engineering"
showing 10 items of 1099 documents
Motivation to Study for PhD Degree: Case of Latvia
2014
AbstractThis paper studies what goals individuals pursue when enrolling in doctoral studies and how it affects the characteristics of the university they find important for choosing it and information sources on doctoral programme they find useful. It uses data collected in 2014 from PhD students and PhD candidates in 14 universities in Latvia and from students born in Latvia but studying abroad. The main result is substantial heterogeneity of goals by field of study, allowing to divide the latter into three groups. Group 1 contains arts & humanities, economics, and education & psychology. Compared to it, students from Group 2 (biology, agriculture, environment & geoscience; physics, mathem…
FACTORES HUMANOS ASOCIADOS A LOS ACCIDENTES MORTALES DE MOTOCICLETAS SCOOTER EN ESPAÑA
2017
Resumen Los accidentes de motocicleta son uno de los problemas de seguridad vial más importantes a nivel mundial. Hay una escasez de estudios específicos sobre las características de la accidentalidad de las motocicletas de tipo scooter, motivada por la falta de una definición precisa de este tipo de motocicleta y de la identificación de los distintos tipos de vehículos de dos ruedas en los registros de accidentes. El objetivo de este trabajo es determinar las características de los 293 conductores de motocicletas scooter fallecidos en España durante el periodo 2006-2011. Se realizaron análisis descriptivos y de asociación en función de la naturaleza de las variables. Los resultados de los …
Quasi-Fractional Models of Human Tendons Hereditariness
2018
In this study, the authors, after collecting a series of experimental evidences following a creep and relaxation tendon campaign, propose a non-linear model of the viscoelastic behavior of the tendons. The ligaments investigated are the patellars and the hamstrings. The analytical model proposed by the authors aims to explain the non-linear hereditary behavior of these tissues and proposes an approach with which to develop a hereditary fractional-order non-linear model.
A New Simple Function for Combustion and Cyclic Variation Modeling in Supercharged Spark Ignition Engines
2022
Research in the field of Internal Combustion (IC) engines focuses on the drastic reduction of both pollutant and greenhouse gas emissions. A promising alternative to gasoline and diesel fuel is represented by the use of gaseous fuels, above all green hydrogen but also Natural Gas (NG). In previous works, the authors investigated the performance, efficiency, and emissions of a supercharged Spark Ignition (SI) engine fueled with mixtures of gasoline and natural gas; a detailed research involving the combustion process of this kind of fuel mixture has been previously performed and a lot of experimental data have been collected. Combustion modeling is a fundamental tool in the design and optimi…
Technical and economical comparison between NdFeB and hard ferrites linear electrical generators from sea waves
2015
In this paper the authors perform a technical-economic comparison of two different Tubular Permanent Magnet Linear Machines for sea waves generation by using finite elements analysis. The first configuration includes ferrite rings while the second configuration includes neodymium-iron-boron rings. In order to compare the two types in economic and technical terms, a detailed analysis of the main figures of merit of the two configurations has been carried out. In particular, significant data such as flux distribution, rated voltage and current, axial force, electric power, realization cost and maintenance cost have been compared.
Aspects Regarding Human Resources Management Streamlining within National and International Organizations
2014
Abstract The entire world is changing in order to achieve performance as an essential element designed to meet the needs and interests of individuals, organizations and society, as a whole. For that, it is necessary to efficiently know and use all the resources and possibilities possessed by the organization, among which human resources Management streamlining acquires new dimensions and special significances. Therefore, approaching certain theoretical aspects regarding the necessity and content of human resources Management streamlining within national and international organizations, as well as psychosocial valences in this field represent important social and objective matters, which are…
Experimental test of the performances of a photovoltaic modules model
2015
In this paper, a measurement-based modeling technique for PV panels oriented to power electronics design is proposed. The proposed modelling approach aims at an accurate modeling of the whole PV curve and not only around a few remarkable points. The proposed approach is based on an experimental characterization of the module under test. In fact, the incompleteness of manufacturers' data and the knowledge of physical parameters are the main source of inaccuracy in existing modelling approaches. The proposed approach is applied to a four lumped parameters model of a Conergy E215P solar module. Tests are performed under natural light. The parameter identification procedure is described in deta…
Laser Beam Induced Current measurements on Dye Sensitized Solar Cells and thin film CIG(S,SE)2 modules
2017
Calculating the efficiency of a solar cell depends on a precise knowledge of its area. Indeed, the photoresponse uniformity is essential to improve the manufacturing process. In this work we report on Laser Beam Induced Current measurements performed on CIG(S,Se)2 modules and Dye Sensitized Solar Cells. These measurements, performed via a green and a red HeNe lasers both operating at an optical irradiance of 1 Sun, allowed to obtain an accurate photoresponse map of the specimens and highlighted the non-uniformities with a spatial resolution of 400 μm and 80 μm, respectively.
Impact of Separator Thickness on Temperature Distribution in Single Cell of Polymer Electrolyte Fuel Cell Operated at Higher Temperature of 90 °C and…
2022
The New Energy and Industry Technology Development Organization (NEDO) road map (Japan, 2017) has proposed that a polymer electrolyte fuel cell (PEFC) system, which operates at a temperature of 90 °C and 100 °C, be applied for stationary and mobility usage, respectively. This study suggests using a thin polymer electrolyte membrane (PEM) and a thin gas diffusion layer (GDL), at the same time, to achieve better power-generation performance, at a higher temperature than usual. The focus of this paper is to clarify the effect of separator thickness on the distribution of temperature at the reaction surface (Treact), with the relative humidity (RH) of the supply gasses and initial operation tem…
A Power Law Behavior in the Incentivized Italian Photovoltaic Market
2018
The Italian photovoltaic (PV) marketis analyzed by using the data contained in the database that describes all PV Plants installed in Italy under the incentive program called “2nd Conto Energia”. It is shown that the cumulative probability distribution of the size of the installed PV plants has a broken power tail. An approach to partially quantify the effect of the economic, juridical and technical rules is introduced in order to show how the regulatory body influences the power tail of the cumulative probability curve.