University of Twente Publications
University of Twente Repository provides publications of UT scientific staff, in many cases full text and publicly available.
Full-text = Public
Mostrando recursos 1 - 20 de 21,217
Increasing the competitiveness of e-vehicles in Europe - Figenbaum, Erik; Fearnley, Nils; Pfaffenbichler, Paul; Hjorthol, Randi; Kolbenstvedt, Marika; Emmerling, Bettina; Jellinek, Reinhard; Bonnema, G. Maarten; Ramjerdi, Farideh; Iversen, Lykke Møller
The 2011 EU White Paper on Transport sets ambitious goals for phasing out conventionally fuelled cars in cities. Take-up and expansion of electric vehicles (e-vehicles, or electromobility) are one way to achieve this, as proposed by, i.a., the European Green Cars Initiative, the EU Action Plan on Urban Mobility, European alternative fuels strategy, and so on.
This paper discusses incentives for the take-up and use of e-vehicles that are in place in different European countries. Especially, it analyses Norway and Austria, in order to establish and understand factors influencing the competitiveness of e-vehicles and potential market penetration. Norway currently enjoys...
α-Synuclein oligomers distinctively permeabilize complex model membranes - Stefanovic, A.; Stockl, M.T.; Claessens, M.M.A.E.; Subramaniam, V.
α-Synuclein oligomers are increasingly considered to be responsible for the death of dopaminergic neurons in Parkinson's disease. The toxicity mechanism of α-synuclein oligomers likely involves membrane permeabilization. Even though it is well established that α-synuclein oligomers bind and permeabilize vesicles composed of negatively-charged lipids, little attention has been given to the interaction of oligomers with bilayers of physiologically relevant lipid compositions. We investigated the interaction of α-synuclein with bilayers composed of lipid mixtures that mimic the composition of plasma and mitochondrial membranes. In the present study, we show that monomeric and oligomeric α-synuclein bind to these membranes. The resulting membrane...
DeepWind-from Idea to 5 MW Concept - Paulsen, Uwe S.; Madsen, Helge A.; Kragh, Knud A.; Nielsen, Per H.; Baran, Ismet; Hattel, Jesper; Ritchie, Ewen; Leban, Krisztina; Svendsen, Harald; Berthelsen, Petter A.
The DeepWind concept has been described previously on challenges and potentials, this new offshore floating technology can offer to the wind industry . The paper describes state of the art design improvements, new simulation results of the DeepWind floating vertical axis wind turbine concept, which implies a high potential for cost saving. The most critical aspects of the concept are addressed in proving feasibility, and if it can be scaled up to 20 MW. Applying structural mechanics, generator, floater & mooring system, control system design, and rotor design using detailed integrated models, results have evolved to a 5 MW baseline...
Thermo-mechanical process modelling of industrially pultruded parts having UD and CFM layers - Baran, Ismet; Hattel, Jesper H.; Akkerman, Remko
Numerical process simulation of an industrially pultruded rectangular hollow profile is presented. The product contains the continuous filament mat (CFM) and the uni-directional(UD) roving layers made of glass/polyester. The distortion and stress evolutions together with the temperature and degree of fields are predicted by the simulation tool developed by the authors. The predicted deformation pattern at the end of the process is found to agree quite well with the one for the real pultruded part in a commercial pultrusion company. A parametric study is also performed based on the total volumetric shrinkage of the resin system during curing. The process...
Investigation of process induced residual stresses and deformations for industrially pultruded parts having UD and CFM layers - Baran, Ismet; Hattel, Jesper H.; Akkerman, Remko
Pultrusion process is one of the most effective manufacturing techniques for production of composite materials having constant cross-sectional area. Pultruded composite profiles are getting increasingly popular in construction industry as well as in wind energy due to their high strength-to-weight ratio, low maintenance cost and high corrosion resistance. Recently, pultruded profiles are foreseen to have potential for the replacement of some of the conventional materials used in the construction industry. An example of this is the increased application of structural pultruded profiles for bridge constructions. A consequence of the enhanced usage of pultruded profiles requires detailed understanding of the mechanical...
Design Optimization of a 5 MW Floating Offshore Vertical-axis Wind Turbine - Paulsen, Uwe Schmidt; Madsen, Helge Aagård; Hattel, Jesper Henri; Baran, Ismet; Nielsen, Per Hørlyck
This paper outlines results of a proposed layout of a light 2-bladed rotor, with a driving torque constraint matching the generator design, and shows details of the pultruded blade – and rotor geometry. In comparison with the 1st baseline design of a 5 MW VAWT concept this present development provides during standstill and operation significant less mass with a comparable level of loading strain in the blades and in the junctions between blade and tower. Optimized blade profile having a low weight and high stiffness is obtained according to the design evaluations based on the standstill calculations in ANSYS software....
Computational Approaches for Modeling the Multiphysics in Pultrusion Process - Carlone, P.; Baran, I.; Hattel, J.H.; Palazzo, G.S.
Pultrusion is a continuous manufacturing process used to produce high strength composite profiles with constant cross section. The mutual interactions between heat transfer, resin flow and cure reaction, variation in the material properties, and stress/distortion evolutions strongly affect the process dynamics together with the mechanical properties and the geometrical precision of the final product. In the present work, pultrusion process simulations are performed for a unidirectional (UD) graphite/epoxy composite rod including several processing physics, such as fluid flow, heat transfer, chemical reaction, and solid mechanics. The pressure increase and the resin flow at the tapered inlet of the die are...