Search results for " wind"
showing 10 items of 403 documents
Leading Edge Erosion of Wind Turbine Blades: Effects of Environmental Parameters on Impact Velocities and Erosion Damage Rate
2021
Abstract Leading edge erosion (LEE) of a wind turbine blade (WTB) is a complex phenomenon that contributes to high operation and maintenance costs. The impact between rain droplets and rotating blades exerts cyclic fatigue stresses on the leading edge — causing progressive material loss and reduced aerodynamic performance. One of the most important parameters for erosion modelling and damage prediction is the relative impact velocity between rain droplets and rotating blade and depends upon the environmental conditions. The environmental condition, in general, could vary for onshore and offshore wind turbines (OWTs) — for instance, the presence of wave-induced loads along with less turbulen…
Energy evaluation and life cycle assessment of an innovative building integrated technology: the smart window-luminescent solar concentrator
2022
Luminescent Solar Concentrators (LSC) represent one of the innovative and potentially most versatile technologies related to Building Integrated Photovoltaics (BIPV). The peculiarity of these devices lies in the fact that they can be integrated into the surface of the building to replace openings such as skylights or windows, thanks to their characteristic of being semi-transparent and of functioning both with direct and diffused radiation. Eni developed the own technology Eni Ray Plus® based on LSC and integrated it in a multifunctional smart window-LSC (SW-LSC) prototype. The device uses the energy produced by LSC modules to power an autonomous and passive shading system, exploiting irrad…
Seasonal periodicity of growth and composition in valves of Diplodon chilensis patagonicus (d'Orbigny, 1835)
2008
Freshwater mussels of the genus Diplodon (Unionida) are common inhabitants of lakes and rivers in South America, and have slow growth and long life spans. We established the annual periodicity of incremental shell growth in Diplodon chilensis patagonicus (d'Orbigny, 1835) and calculated growth rates at different ages, using internal ring counting supported by dyeing methods and δ 18 O isotope analyses, in two Patagonian populations (Lago Steffen and its effluent Rio Manso Inferior, Argentina). Longevities of ca. 90 years (Lago Steffen) significantly extend the life spans reported in the past. Growth rates for old individuals (>30 years) from both lake and river populations average 0.16 mm p…
On-line assessment of comprehension processes
2009
In this paper we describe a new version of a former paper-and-pencil standardized comprehension test called Test of Comprehension Processes (Vidal-Abarca, Gilabert, Martínez, & Sellés, 2007). The new version has been adapted to a computer-based environment based on the moving window technique. It can be used to assess comprehension strategies of students from fifth to tenth grades (11 to 16 years old). Comprehension strategies are registered on-line using reading times and visits to relevant sections of the text during the question-answering process. Data show that the computerbased version draws similar results to those provided by the paper-and-pencil version. In addition, we identify the…
Method to find the Minimum 1D Linear Gradient Model for Seismic Tomography
2016
The changes in the state of a geophysical medium before a strong earthquake can be found by studying of 3D seismic velocity images constructed for consecutive time windows. A preliminary step is to see changes with time in a minimum 1D model. In this paper we develop a method that finds the parameters of the minimum linear gradient model by applying a two-dimensional Taylor series of the observed data for the seismic ray and by performing least-square minimization for all seismic rays. This allows us to obtain the mean value of the discrete observed variable, close to zero value.
Luminescent Solar Concentrator (LSC): preliminary phases of the LCA analysis applied to the Smart Window-LSC
2019
Luminescent solar concentrators (LSC) represent one of the innovative technologies related to Building Integrated PhotoVoltaics (BIPV). T hanks to their characteristic of being semi-transparent and of functioning both with direct and diffused radiation, the se devices can be integrated to the surface of the buildings, in particular in replacement of openings such as skylights or windows. They do not require solar tracking systems that are used in classic solar concentrators and allow reducing the presence of silicon compared to traditional photovoltaic panels.
Comparison of line-by-line and band models of near-IR methane absorption applied to outer planet atmospheres
2012
Import OPTIWOS; International audience; Recent improvements in high spectral resolution measurements of methane absorption at wavenumbers between 4800 cm(-1) and 7919 cm(-1) have greatly increased the number of lines with known lower state energies, the number of weak lines, and the number of lines observed at low temperatures (Campargue, A., Wang, L, Kassi, S., Masat, M., Votava, O. [2010]. J. Quant. Spectrosc. Radiat. Trans. 111, 1141-1151; Campargue, A., Wang, L, Liu, A.W., Hu, S.M., Kassi, S. [2010]. Chem. Phys. 373, 203-210; Mondelain, D., Kassi, S., Wang, L.C. [2011]. Phys. Chem. Chem. Phys. 13, 7985-7996; Nikitin, A.V. et al. [2011a]. J. Mol. Spectrosc. 268, 93-106; Nikitin, A.V. et …
Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe–Metis/Solar Orbiter Observations
2022
Abstract The solar wind measured in situ by Parker Solar Probe in the very inner heliosphere is studied in combination with the remote-sensing observation of the coronal source region provided by the METIS coronagraph aboard Solar Orbiter. The coronal outflows observed near the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and 6.3 R ⊙ above the eastern solar limb, can be associated with the streams sampled by PSP at 0.11 and 0.26 au from the Sun, in two time intervals almost 5 days apart. The two plasma flows come from two distinct source regions, characterized by different magnetic field polarity and intensity at the coronal base. It follows that both the global and local p…
Hydrogen non-equilibrium ionisation effects in coronal mass ejections
2020
This research has received funding from the Science and Technology Facilities Council (UK) through the consolidated grant ST/N000609/1 and the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (grant agreement No. 647214). D.H.M. would like to thank both the UK STFC and the ERC (Synergy grant: WHOLE SUN, grant Agreement No. 810218) for financial support. D.H.M. and P.P. would like to thank STFC for IAA funding under grant number SMC1-XAS012. This work used the DiRAC@Durham facility man-aged by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk. The equipment was funded by BEIS capital fundin…
Directional Deep Brain Stimulation for Parkinson's Disease: Results of an International Crossover Study With Randomized, Double-Blind Primary Endpoin…
2022
Objective Published reports on directional deep brain stimulation (DBS) have been limited to small, single-center investigations. Therapeutic window (TW) is used to describe the range of stimulation amplitudes achieving symptom relief without side effects. This crossover study performed a randomized double-blind assessment of TW for directional and omnidirectional DBS in a large cohort of patients implanted with a DBS system in the subthalamic nucleus for Parkinson's disease. Materials and methods Participants received omnidirectional stimulation for the first three months after initial study programming, followed by directional DBS for the following three months. The primary endpoint was a…