Search results for "Energy engineering"
showing 10 items of 1099 documents
Simulation and laboratory experimental tests of a line to shield medium voltage power line communication system
2011
A complete model of a power-line communication (PLC) system on a medium-voltage (MV) network in the case of a line-shield configuration is presented in this paper. An MV cable model in a line-shield configuration is considered together with the power transformers, the signal coupling networks, and the receiving and transmitting line coupling interface of a ST7540 FSK power-line transceiver. Simulations of the complete model of the system under consideration have been carried out for different line lengths, with and without power transformers and derivation branches. The model is validated by experimental tests performed in the laboratory. The measured results confirm the reliability of the …
Zero Ripple Current with Coupled Inductors in Continuous Conduction Mode under PWM Signals
2020
This article presents a generalized analysis to explain current ripple of an $m$ windings coupled inductor with a given coupling factor $k_{ij}$ for each pair of windings and then studies more in detail its use in the continuous conduction mode and with pulsewidth modulated signals. To determine the current ripple, a generalized expression of the equivalent inductance of each winding is calculated, including the influence of voltage unbalance. In the ideal case, the equivalent inductance shows that the current ripple can only become $m$ times smaller than that with uncoupled inductors. But in the unbalanced case, some divergences of the equivalent inductance appear that are responsible for …
Synthesis of Cuboctahedral CeO2 Nanoclusters and Their Assembly into Cuboid Nanoparticles by Oriented Attachment
2017
Here, we describe a simple approach to control the oriented attachment process through selective ligand scavenging from the {100} facets of CeO2 nanoclusters. Aggregates of these nanoclusters smaller than 10 nm with controlled shapes and exposed facets were obtained. For the synthesis of the cuboctahedral CeO2 nanoclusters, we developed a solvent-controlled synthesis approach based on a non-hydrolytic sol–gel process and used an ester aminolysis reaction to control ligand scavenging from the {100} facets. First-principle calculations allowed us to understand and interpret, at the atomic level, the effects of shape control on the synthesis. Fine-tuning of the desired morphologies can be achi…
Reivindicaciones culturales y feminismos disidentes, una mirada nada normalizadora
2020
espanolLas reivindicaciones de las culturas se desajustan del modelo ilustrado, en ese aspecto, el proposito de este ensayo es dilucidar de manera sucinta, las diferentes deconstrucciones y exclusiones culturales que nos encontramos en distintos paradigmas teoricos. La diferencia monopoliza el debate en un escenario multietnico y globalizador. Los feminismos, diferentes entre si, abogan por seguir reconceptualizando terminos, y desmontando argumentos universalizadores, en base a la hibridacion humana, en cambio, no diferencia las imbricaciones a lo largo de la humanidad. No obstante, las culturas son constantes creaciones, recreaciones y negociaciones de fronteras entre nosotros/as y el/la/…
Brand Communication Challenges in Getting Young Customer Engagement
2014
Abstract It is important for the Brands of products and services that address young people to get to know very well this consumer segment, although they are extremely open minded, bold, friendly and great fans of brands. Nevertheless they are not so easy to deal with or to be convinced by one brand or another, but once they prove to be loyal they are highly valuable. In order to win their loyalty, companies must take into account a certain number of aspects.
Special Issue - Past, present and future challenges on customer experience: Digging knowledge across sectors
2019
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POSS-Al-porphyrin-imidazolium cross-linked network as catalytic bifunctional platform for the conversion of CO2 with epoxides
2023
Two heterogeneous catalysts were prepared with the aim of following the promising path of CO2 fixation into epoxides. The synthetic procedure involves a radical copolymerization of an octavinylsilsesquioxane as inorganic core building block and tetrastyrylporphyrin aluminum chloride monomer (TSP-AlCl) in presence (POSS-TSP-AlCl-imiBr) or in absence (POSS-TSP-AlCl) of a bis-vinylimidazolium bromide salt (bis-imiBr), in order to investigate if the bifunctional heterogeneous material can display better catalytic performance than the separate species. All the solids were fully characterized and tested in the synthesis of cyclic carbonates starting from CO2 and several epoxides. The synergic coo…
The Strategy and the Reasons of the Republic of Moldova's Association with European Union
2014
Abstract The European Union and the Republic of Moldova negotiated an Association Agreement (AA) in 2010, and a Deep and Comprehensive Free Trade Area (DCFTA) in 2012. After completion of negotiations and initialling of AA, before the full Agreement can enter into force, action is needed to ensure that the Parties are able to enjoy the full benefits of the Agreement. SMEs play a focal role in the implementation of the future DCFTA. The article describes the economic and political basis for association/integration, outlining the importance of SMEs. This article is reasoning for future PhD research in this area.
Condition Monitoring Technologies for Synthetic Fiber Ropes - a Review
2020
This paper presents a review of different condition monitoring technologies for fiber ropes. Specifically, it presents an overview of the articles and patents on the subject, ranging from the early 70’s up until today with the state of the art. Experimental results are also included and discussed in a conditionmonitoring context,where failuremechanisms and changes in physical parameters give improved insight into the degradation process of fiber ropes. From this review, it is found that automatic width measurement has received surprisingly little attention, and might be a future direction for the development of a continuous condition monitoring system for synthetic fiber ropes.
Load frequency regulation using observer based non-linear sliding mode control
2019
Abstract In this paper, the generalized extended state observer (GESO) and non-linear sliding mode control (SMC) are merged together to study the frequency deviation problem in multi-area power system. In study, the GESO is used not only for state and disturbance estimation but also for disturbance rejection of the system. The said observer ensures accurate estimation of the actual states leading to convergence of estimation error to zero. The non-linear SMC is used to increase the damping ratio of the system whenever, any perturbations occurs. The proposed observer based controller is compared with an existing two-layer active disturbance rejection control (ADRC) and also validated on larg…