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Groen, J.P. (author), Wu, J. (author), Sigmund, Ole (author)This paper concerns compliance minimization and projection of coated structures with orthotropic infill material in 2D. The purpose of the work is two-fold. First, we introduce an efficient homogenization-based approach to perform topology optimization of coated structures with orthotropic infill material. The design space is relaxed to allow...journal article 2019
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Zhao, Dong (author), Lenz, Thomas (author), Gelinck, Gerwin H. (author), Groen, W.A. (author), Damjanovic, Dragan (author), de Leeuw, D.M. (author), Katsouras, Ilias (author)Depolarization in ferroelectric materials has been studied since the 1970s, albeit quasi-statically. The dynamics are described by the empirical Merz law, which gives the polarization switching time as a function of electric field, normalized to the so-called activation field. The Merz law has been used for decades; its origin as domain-wall...journal article 2019
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Landman, H.M. (author), Davies, Simon (author), Groen, Eric L. (author), van Paassen, M.M. (author), Lawson, Nicholas (author), Bronkhorst, Adelbert W. (author), Mulder, Max (author)We hypothesized that an incorrect expectation due to spatial disorientation may induce roll reversal errors. To test this, an in-flight experiment was performed, in which forty non-pilots rolled wings level after receiving motion cues. A No-leans condition (subthreshold motion to a bank angle) was included, as well as a Leans-opposite condition ...journal article 2019
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Knulst, A.J. (author), Gupta, Shailvi (author), Groen, Reinou S. (author), Maharjan, Dipak (author), Kapendra, Amatya S. (author), Dankelman, J. (author), Kushner, Adam L. (author)Objectives: Lack of access to safe surgery is seen as a major issue that needs to be addressed. The aim of this study was to understand which combinations of factors relate to high occurrences of unmet needs and disability in Nepal, and consequently, how to focus future work to maximise impact in this country. Methods: A large population...journal article 2019
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Groen, Brenda (author), van der Voordt, Theo (author), Hoekstra, B.S. (author), van Sprang, Hester (author)Purpose: This paper aims to explore the relationship between satisfaction with buildings, facilities and services and perceived productivity support and to test whether the findings from a similar study of Batenburg and Van der Voordt (2008) are confirmed in a repeat study after 10 years with more recent data. Design/methodology/approach:...journal article 2019
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Thomas, Miguel (author), Bossche, A. (author), Groen, W.A. (author), Bastemeijer, J. (author), Steijlen, A.S.M. (author), French, P.J. (author)Sweating is a normal reaction of the body to exercise. Although much of sweat is water, there are many other components. These components can be an indication of the condition of the athlete. Increase of elements and salts in the tissue will also work their way through to the sweat. Measurement directly in tissue can be an excellent indicator,...conference paper 2019
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Stuber, V.L. (author), Deutz, Daniella B. (author), Bennett, James (author), Cannel, David (author), de Leeuw, D.M. (author), van der Zwaag, S. (author), Groen, W.A. (author)Vibrational piezoelectric energy harvesters are being investigated to replace batteries in embedded sensor systems. The energy density that can be harvested depends on the figure of merit, d<sub>33</sub>g<sub>33</sub>, where d<sub>33</sub> and g<sub>33</sub> are the piezoelectric charge and voltage coefficient. Commonly used piezoelectric...journal article 2019
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Swamy, A. (author), Burström, Gustav (author), Spliethoff, Jarich W. (author), Babic, Drazenko (author), Reich, Christian (author), Groen, Joanneke (author), Edström, Erik (author), Terander, Adrian Elmi (author), Racadio, John M. (author), Dankelman, J. (author), Hendriks, B.H.W. (author)Safe and accurate placement of screws remains a critical issue in open and minimally invasive spine surgery. We propose to use diffuse reflectance (DR) spectroscopy as a sensing technology at the tip of a surgical instrument to ensure a safe path of the instrument through the cancellous bone of the vertebrae. This approach could potentially...journal article 2019
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Stuber, V.L. (author), Mahon, T.R. (author), van der Zwaag, S. (author), Groen, W.A. (author)Polymer-piezoceramic composites have drawn a lot of attention for sensor and energy harvesting applications. Poling such materials can be difficult due to the electric field getting mostly distributed over the low dielectric constant matrix. During this process, the electrical matrix conductivity plays a vital role. This work shows how two...journal article 2019
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Mahon, T.R. (author), Stuber, V.L. (author), Ammu, S.K. (author), van der Zwaag, S. (author), Groen, W.A. (author), Hoeks, T. (author), Guhathakurtha, S. (author)While most of the work on piezoelectric composites focuses on methods to reduce the dielectric constant of the composite (for better sensor and energy harvesting performance), for haptic feedback and actuator applications the opposite is desirable. We present here a study of the effect of adding a second ceramic phase (BaTiO3 nanoparticles)...conference paper 2019
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Khaliq, J. (author), Hoeks, Theo (author), Groen, W.A. (author)In this paper, we present a method to create a highly sensitive piezoelectric quasi 1–3 composite using a thermoplastic material filled with a piezoelectric powder. An up-scalable high-temperature dielectrophoresis (DEP) process is used to manufacture the quasi 1–3 piezoelectric polymer-ceramic composites. For this work, thermoplastic cyclic...journal article 2019
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Tuluk, A. (author), Mahon, T.R. (author), van der Zwaag, S. (author), Groen, W.A. (author)BiFeO<sub>3</sub> is a multiferroic material with the perovskite structure which is promising for use in sensors and transducers. Single phase production of BiFeO<sub>3</sub> remains a challenge, however. In this study, the optimal calcination temperature to obtain close to single phase powder was determined to be 750°C. The sintering...conference paper 2019
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Landman, H.M. (author), van Oorschot, P. (author), van Paassen, M.M. (author), Groen, Eric L. (author), Bronkhorst, Adelbert W. (author), Mulder, Max (author)Objective: This study tested whether simulator-based training of pilot responses to unexpected or novel events can be improved by including unpredictability and variability in training scenarios. Background: Current regulations allow for highly predictable and invariable training, which may not be sufficient to prepare pilots for unexpected...journal article 2018
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Deutz, D.B. (author), Pascoe, J.A. (author), Schelen, J.B.J. (author), van der Zwaag, S. (author), de Leeuw, D.M. (author), Groen, W.A. (author)Piezoelectric energy harvesters are at the front of scientific research as enablers of renewable, sustainable energy for autonomous wireless sensor networks. Crucial for this disruptive technology is the achievable output power. Here we show, analytically, that the maximum output energy per unit volume, under a single sinusoidal excitation,...journal article 2018
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Kommeren, Sander (author), Coenen, Michiel J.J. (author), Eggenhuisen, Tamara M. (author), Slaats, Thijs M.W.L. (author), Gorter, Harrie (author), Groen, W.A. (author)A commonly used strategy in the fabrication of organic electronics involves the use of orthogonal solvents, i.e. the alternating use of organic solvents and water for the application of consecutive layers to prevent dissolution of previous layers. This strategy therefore requires the deposition of sequential layers with a large mismatch in...journal article 2018
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Oosting, R.M. (author), Dankelman, J. (author), Wauben, L.S.G.L. (author), Madete, J. (author), Groen, R. S. (author)Safe and affordable surgery is not accessible for five billion people when they need it. Multiple surgical capacity studies have shown that hospitals in low-And-middle income countries do not have complete coverage of basic surgical equipment such as, theatre lights, anesthesia machines and electro surgical units. Currently, almost all...conference paper 2018
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Katerinopoulou, Dimitra (author), Zalar, Peter (author), Sweelssen, Jorgen (author), Kiriakidis, George (author), Rentrop, Corné (author), Groen, W.A. (author), Gelinck, Gerwin H. (author), van den Brand, Jeroen (author), Smits, Edsger C.P. (author)Surfaces which can accurately distinguish spatial and temporal changes in temperature are critical for not only flow sensors, microbolometers, process control, but also future applications like electronic skins and soft robotics. Realizing such surfaces requires the deposition of thousands of thermal sensors over large areas, a task ideally...journal article 2018
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Galagan, Yulia (author), Di Giacomo, Francesco (author), Gorter, Harrie (author), Kirchner, Gerwin (author), de Vries, Ike (author), Andriessen, Ronn (author), Groen, W.A. (author)The feasibility of upscaling the perovskite solar cells technologies to high volume production using roll-to-roll (R2R) slot die coating is demonstrated in this study. Perovskite solar cells are produced by R2R slot die coating on flexible substrates with a width of 30 cm and the web speed of 3–5 m min−1. R2R deposition of the electron transport...journal article 2018
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Isabelli, Fabiano (author), Di Giacomo, Francesco (author), Gorter, Harrie (author), Brunetti, Francesca (author), Groen, W.A. (author), Andriessen, Ronn (author), Galagan, Yulia (author)Current laboratory-scale fabrication of perovskite solar cells involves the use of toxic solvents in the different fabrication steps. The aim of this research is to find a nontoxic alternative to chlorobenzene used for the deposition of hole transport material (HTM) spiro-OMeTAD. The initial selection of the solvents compatible with...journal article 2018
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Abbel, Robert (author), Galagan, Yulia (author), Groen, W.A. (author)The production of electronic devices using solution based (“wet”) deposition technologies has some decisive technical and commercial advantages compared to competing approaches like vacuum based (“dry”) manufacturing. Particularly, the potential to scale up production processes to large areas and high volumes by introducing continuous roll-to...review 2018