Search results for "wind"
showing 10 items of 846 documents
Determination of the Time Window of Event-Related Potential Using Multiple-Set Consensus Clustering
2020
Clustering is a promising tool for grouping the sequence of similar time-points aimed to identify the attention blocks in spatiotemporal event-related potentials (ERPs) analysis. It is most likely to elicit the appropriate time window for ERP of interest if a suitable clustering method is applied to spatiotemporal ERP. However, how to reliably estimate a proper time window from entire individual subjects’ data is still challenging. In this study, we developed a novel multiset consensus clustering method in which several clustering results of multiple subjects were combined to retrieve the best fitted clustering for all the subjects within a group. Then, the obtained clustering was processed…
Modelling the effect of porosity on the mechanical properties of unidirectional composites. The case of thick-walled pressure vessels
2018
International audience; The present article highlights morphological features present in composite pressure vessels. The use of X-ray microtomography provides three-dimensional information about the voids in a large thick-walled type 3 pressure vessel at the mesoscopic scale. The observations show that the porosity structure depends strongly on composite thickness and orientation. A numerical approach is proposed to model realistically the damage phenomena in pressure vessels.
Rain on building façades
2006
Rain is one of the main causes of moisture damage to the building envelope, leading to problems such as rain penetration, frost and salt damage, discoloration by leaching, soiling by differential washing, etc. The potential of deterioration due to rain depends on the façade material, the junction of building envelope components, the overall geometry of the building, but also the presence or absence of modulation on the façade. In this paper, Computational fluid dynamics (CFD) simulations are used to analyze these effects and illustrated with examples taken in Sicily. It is firstly shown that buildings protect themselves from driving rain due to the wind blocking effect, but that façade open…
Nano-graphite cold cathodes for electric solar wind sail
2015
The nanographite (NG) films consisting of tiny graphite crystallites (nanowalls) are produced by carbon condensation from methane–hydrogen gas mixture activated by a direct current discharge. High aspect ratio and structural features of the NG crystallites provides efficient field electron emission (FE). Applicability and performance of the NG films in an electron gun (E-gun) of a solar wind thruster system with an electric sail (E-sail) is tested. The long-term tests are demonstrated suitability of E-gun assembly with the NG cathodes for the real space missions. The results of the tests are analyzed and physical mechanisms of the cathode aging and practical methods for improvement performa…
Modeling foreign exchange market activity around macroeconomic news: Hawkes-process approach
2015
We present a Hawkes-model approach to the foreign exchange market in which the high-frequency price dynamics is affected by a self-exciting mechanism and an exogenous component, generated by the pre-announced arrival of macroeconomic news. By focusing on time windows around the news announcement, we find that the model is able to capture the increase of trading activity after the news, both when the news has a sizable effect on volatility and when this effect is negligible, either because the news in not important or because the announcement is in line with the forecast by analysts. We extend the model by considering noncausal effects, due to the fact that the existence of the news (but not…
Impact of pharmacological and environmental manipulations on neuronal structural plasticity and dynamics
2017
El sistema nervioso de vertebrados es uno de los más estudiados, aunque peor comprendidos, del organismo de mamíferos. Desde que Ramón y Cajal postuló su teoría celular de este sistema (Ramón y Cajal 1909), la neurona se ha postulado como su unidad funcional. Sin embargo, durante las últimas décadas se ha revolucionado la visión que se tenía de éste. Una de las percepciones más asentadas era que, tras el desarrollo embrionario, el sistema nervioso se mantenía inmutable. Sin embargo, ahora sabemos que diferentes formas de plasticidad gobiernan su adaptación, que son necesarias para importantes procesos del día a día, tales como el aprendizaje y la memoria (Smythies 2002; Berlucchi and Buchte…
Efficient numerical methods for simulating continuous casting processes
2014
QCloud-API for synchronous and asynchronous file transfer in Qt
2012
Pilvipalveluiden käyttö ohjelmissa on lisääntynyt, sillä niiden avulla voidaan tarjota uusia ominaisuuksia suhteellisen pienellä vaivalla. Kuitenkin eri palveluntarjoajien eroista johtuen pilvipalvelusta toiseen siirtyminen on vaikeaa, ja usein vaatii mittavaa uudelleen koodausta ohjelmassa. Tämän gradun tarkoitus oli yhdistää eri pilvipalveluntarjoajien palvelut saman APIn taakse, ja näin tarjota helpompi tapa siirtyä yhdestä palvelusta toiseen. Esitelty QCloud-API tarjoaa tarpeelliset ominaisuudet Windows Azuren ja Amazonin S3 palveluiden käyttöön yhden APIn kautta, jolloin palvelusta toiseen ei vaadi ohjelmassa kuin korkeintaan yhden rivin muutoksen. There is growing need for using servi…
A probabilistic long‐term framework for site‐specific erosion analysis of wind turbine blades: A case study of 31 Dutch sites
2021
Abstract Rain‐induced leading‐edge erosion (LEE) of wind turbine blades (WTBs) is associated with high repair and maintenance costs. The effects of LEE can be triggered in less than 1 to 2 years for some wind turbine sites, whereas it may take several years for others. In addition, the growth of erosion may also differ for different blades and turbines operating at the same site. Hence, LEE is a site‐ and turbine‐specific problem. In this paper, we propose a probabilistic long‐term framework for assessing site‐specific lifetime of a WTB coating system. Case studies are presented for 1.5 and 10 MW wind turbines, where geographic bubble charts for the leading‐edge lifetime and number of repai…