Search results for "Energy engineering"
showing 10 items of 1099 documents
Sampling procedure in a willow plantation for chemical elements important for biomass combustion quality
2015
Willow (Salix spp.) is expected to contribute significantly to the woody bioenergy system in the future, so more information on how to sample the quality of the willow biomass is needed. The objectives of this study were to investigate the spatial variation of elements within shoots of a willow clone ‘Tordis’, and to reveal the relationship between sampling position, shoot diameters, and distribution of elements. Five Tordis willow shoots were cut into 10–50 cm sections from base to top. The ash content and concentration of twelve elements (Al, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Si, and Zn) in each section were determined. The results showed large spatial variation in the distribution of mos…
New Energy Corridors in the Euro-Mediterranean Area: The Pivotal Role of Sicily
2018
The present paper deals with the new opportunities deriving from the interconnections of the European and North African transmission systems. In order to achieve a single international market for electricity exchanges, interconnections between networks in different countries are becoming increasingly important and Sicily, for its geographical position in the middle of the Mediterranean Sea, will undoubtedly play an important role as an electrical bridge between Europe and the North Africa in the near future. The paper, presenting the actual electro-energetic context of Tunisia, reports the new important interconnection already realized in South Italy (in particular in Sicily) and describe t…
Designing an Energy Management System for smart houses
2015
Most advantages that the smart grid will bring derive from its capability of improving reliability performance and customers' responsiveness and encouraging greater efficiency decisions by the customers. In this optic, the paper presents an innovative Energy Management System for smart houses, allowing the optimization of the electricity cost and electrical energy consumption and, at the same time, preserving the end-user comfort.
Markov Model for Tweets Geographic Distribution Characterization
2015
Abstract In this paper we will continue our researches regarding e-Business and e-Government modeling on Social Media presented in (Stoica, Pitic, & Mihaescu, 2013). Among message and user parameters we add a new parameter used to describe the geographical dispersion of Twitter messages. This new parameter will characterize the way one set of messages will spread in Social Graph from the physical word point of view. The first model, presented as “A Novel Model for E-Business and E-Government Processes on Social”, will be extended with the geographical parameter PG. We will define and we will describe the Markov Model used to organize the messages gathered from social media. The main idea of…
New Media E-marketing Campaign. Case Study for a Romanian Press Trust
2014
Abstract The impact of new media on the organization of the companies has increased a lot in the recent years. This was achieved either through the implementation of new media tools for the business management, or by opening up to clients or other companies using social media. Attracting new customers and communicate with them by using social media platforms such as Facebook or Twitter that have become a necessity. In this work we have done a case study applied to press trust in Romania. For a period of 2 years will be done a total of 5 marketing campaigns on the social network platform Facebook. In this paper we will present the results of the first three campaigns, the other two still bei…
Feasibility analysis and study of a grid-connected hybrid electric system: Application in the building sector
2016
This paper represents the feasibility study and analysis of a grid-connected hybrid (PV-Wind) system with battery, realized within the project DE.DU.ENER.T and installed in the research centre CRTEn located in the northern Tunisia in the city of Borj-Cedria. The main objective of this work is to exploit renewable sources of electrical energy production to electrify the desired building. So, to minimize electricity consumption costs, reduce the adverse effects of pollutants products from the diesel power systems and sometimes happen to sell the surplus of energy produced. The HOMER (Hybrid Optimization Model of Electric Renewable) software is used to estimate system size and its performance …
Influence of doped charge transport layers on efficient perovskite solar cells
2018
Planar vacuum deposited p–i–n methyl ammonium lead tri-iodide perovskite solar cells are prepared with different electron and hole transporting layers, either doped or undoped. The effect of these layers on the solar cells performance (efficiency and stability) is studied. The main benefit of using doped layers lies in the formation of barrier free charge extraction contacts to the electrodes. However, this comes at the cost of increased residual absorption (reducing the current density and efficiency of the cells) and a decreased stability. A generic solar cell structure using undoped charge extraction layers is presented, containing a thin layer of a strong electron acceptor in between th…
Experimental assessment of application of gravimetric measurements for pneumatic conveying in horizontal pipelines
2008
Abstract Available theoretical considerations and practical experiments usually concern aspiration in the vertical pipelines, where the procedure of making measurements is universally known and it does not express any reservations. However, it is often necessary to conduct test in the systems of horizontal conveying of solgas, where the conditions of taking a representative sample, even for the sake of the significant effect of the gravitational force, many vary from those suggested for measurements in the systems with vertical flow. The present paper contains the results of tests which determine usability of the gravimetric method in measurements of flow parameters of two-phase gas–solid m…
The Imperative of Addressing the Contemporary Crisis of Economics with Spiritual Intelligence
2013
Abstract The current global economic crisis has also drawn an increasingly obvious crisis of the economic theories. Thereby are more and more voices that calls for quitting the rather mechanistic, mathematical, determinist or pure rational approaches in favor of either sociological, psychological, historical, cultural or merely ethical ones, or, most often, a combination of some or all of these. In this paper I argue that the most needed approaches are now the anthropological ones that start from the spiritual considerations about human intelligence.
Modeling and Experimental Validation of a Voltage-Controlled Split-Pi Converter Interfacing a High-Voltage ESS with a DC Microgrid
2023
The Split-pi converter can suitably interface an energy storage system (ESS) with a DC microgrid when galvanic isolation is not needed. Usually, the ESS voltage is lower than the grid-side voltage. However, limitations in terms of the ESS current make the use of a high-voltage ESS unavoidable when high power levels are required. In such cases, the ESS voltage can be higher than the microgrid voltage, especially with low microgrid voltages such as 48 V. Despite its bidirectionality and symmetry, the Split-pi exhibits a completely different dynamic behavior if its input and output ports are exchanged. Thus, the present work aims to model the Split-pi converter operating with an ESS voltage hi…