Browsing by Department "Swiss Federal Institute of Technology Lausanne"
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Item Agito ergo sum(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2020-04-01) Bolton, Thomas A.W.; Kebets, Valeria; Glerean, Enrico; Zöller, Daniela; Li, Jingwei; Yeo, B. T.Thomas; Caballero-Gaudes, César; Van De Ville, Dimitri; Swiss Federal Institute of Technology Lausanne; University of Geneva; Department of Neuroscience and Biomedical Engineering; National University of Singapore; Basque Center on Cognition, Brain and LanguageThe impact of in-scanner motion on functional magnetic resonance imaging (fMRI) data has a notorious reputation in the neuroimaging community. State-of-the-art guidelines advise to scrub out excessively corrupted frames as assessed by a composite framewise displacement (FD) score, to regress out models of nuisance variables, and to include average FD as a covariate in group-level analyses. Here, we studied individual motion time courses at time points typically retained in fMRI analyses. We observed that even in this set of putatively clean time points, motion exhibited a very clear spatio-temporal structure, so that we could distinguish subjects into separate groups of movers with varying characteristics. Then, we showed that this spatio-temporal motion cartography tightly relates to a broad array of anthropometric and cognitive factors. Convergent results were obtained from two different analytical perspectives: univariate assessment of behavioural differences across mover subgroups unraveled defining markers, while subsequent multivariate analysis broadened the range of involved factors and clarified that multiple motion/behaviour modes of covariance overlap in the data. Our results demonstrate that even the smaller episodes of motion typically retained in fMRI analyses carry structured, behaviourally relevant information. They call for further examinations of possible biases in current regression-based motion correction strategies.Item Catalytic valorization of lignocellulose and its derived feedstocks into fuels and chemicals(ELSEVIER SCIENCE BV, 2023-01-15) Fei, Zhaofu; Chen, De; Hensen, Emiel J.M.; Li, Yongdan; Jagadeesh, Rajenahally V.; Swiss Federal Institute of Technology Lausanne; Norwegian University of Science and Technology; Eindhoven University of Technology; Department of Chemical and Metallurgical Engineering; Leibniz Institute for CatalysisItem Complementary Metasurfaces for Guiding Electromagnetic Wave(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2021-03) Ma, X.; Mirmoosa, M. S.; Tretyakov, S. A.; Northwestern Polytechnical University; Swiss Federal Institute of Technology Lausanne; Department of Electronics and NanoengineeringMetasurfaces can be employed for designing waveguides that confine the electromagnetic energy while they are open structures. In this communication, we introduce a new type of such waveguides, formed by two penetrable metasurfaces having complementary isotropic surface impedances. We theoretically study the guided modes supported by the proposed structure and discuss the corresponding dispersion properties. We show the results for different scenarios in which the surface impedances possess nonresonant or resonant characteristics, and the distance between the two metasurfaces changes from large values to the extreme limit of zero. We also derive and describe the general condition for existence of two modes with orthogonal polarizations having the same phase velocity. In the particular case in which the metasurfaces are complementary and the distance between them is not small, we indicate that such phenomenon occurs within a broad frequency range. This property can be promising for applications in leaky-wave antennas and field focusing.Item Computed Three-Dimensional Atomic Force Microscopy Images of Biopolymers Using the Jarzynski Equality(AMERICAN CHEMICAL SOCIETY, 2022-06-16) Sumikama, Takashi; Canova, Filippo Federici; Gao, David Z.; Penedo, Marcos; Miyazawa, Keisuke; Foster, Adam S.; Fukuma, Takeshi; Japan Science and Technology Agency; Surfaces and Interfaces at the Nanoscale; Norwegian University of Science and Technology; Swiss Federal Institute of Technology Lausanne; Kanazawa University; Department of Applied PhysicsThree-dimensional atomic force microscopy (3D-AFM) has resolved three-dimensional distributions of solvent molecules at solid-liquid interfaces at the subnanometer scale. This method is now being extended to the imaging of biopolymer assemblies such as chromosomes or proteins in cells, with the expectation of being able to resolve their three-dimensional structures. Here, we have developed a computational method to simulate 3D-AFM images of biopolymers by using the Jarzynski equality. It is found that some parts of the fiber structure of biopolymers are indeed resolved in the 3D-AFM image. The dependency of 3D-AFM images on the vertical scanning velocity is investigated, and optimum scanning velocities are found. It is also clarified that forces in nonequilibrium processes are measured in 3D-AFM measurements when the dynamics of polymers are slower than the scanning of the probe.Item Directional Sensitivity of Cortical Neurons Towards TMS Induced Electric Fields(MIT Press, 2023-11-13) Weise, Konstantin; Worbs, Torge; Kalloch, Benjamin; Souza, Victor H.; Jaquier, Aurelien Tristan; Van Geit, Werner; Thielscher, Axel; Knösche, Thomas R.; Max Planck Institute for Human Cognitive and Brain Sciences; Department of Neuroscience and Biomedical Engineering; Swiss Federal Institute of Technology Lausanne; Technical University of Denmark; Department of Neuroscience and Biomedical EngineeringWe derived computationally efficient average response models of different types of cortical neurons, which are subject to external electric fields from Transcranial Magnetic Stimulation. We used 24 reconstructions of pyramidal cells (PC) from layer 2/3, 245 small, nested, and large basket cells from layer 4, and 30 PC from layer 5 with different morphologies for deriving average models. With these models, it is possible to efficiently estimate the stimulation thresholds depending on the underlying electric field distribution in the brain, without having to implement and compute complex neuron compartment models. The stimulation thresholds were determined by exposing the neurons to TMS-induced electric fields with different angles, intensities, pulse waveforms, and field decays along the somato-dendritic axis. The derived average response models were verified by reference simulations using a high-resolution realistic head model containing several million neurons. The relative errors of the estimated thresholdsbetween the average model and the reference model ranged between -3% and 3.7% in 98% of the cases, while the computation time was only a fraction of a second compared to several weeks. Finally, we compared the model behavior to TMS experiments and observed high correspondence to the orientation sensitivity of motor evoked potentials. The derived models were compared to the classical cortical column cosine model and to simplified ball-and-stick neurons. It was shown that both models oversimplify the complex interplay between the electric field and the neurons and do not adequately represent the directional sensitivity of the different cell types The derived models are simple to apply and only require the TMS induced electric field in the brain as input variable. The models and code are available to the general public in open-source repositories for integration into TMS studies to estimate the expected stimulation thresholds for an improved dosing and treatment planning in the future.Item Evolution of Temporal Coherence in Confined Exciton-Polariton Condensates(2018-01-05) Klaas, M.; Flayac, H.; Amthor, M.; Savenko, I. G.; Brodbeck, S.; Ala-Nissila, T.; Klembt, S.; Schneider, C.; Hoefling, S.; University of Würzburg; Swiss Federal Institute of Technology Lausanne; Institute for Basic Science; Centre of Excellence in Quantum Technology, QTF; University of St Andrews; Department of Applied PhysicsWe study the influence of spatial confinement on the second-order temporal coherence of the emission from a semiconductor mieroeavity in the strong coupling regime. The confinement, provided by etched micropillars, has a favorable impact on the temporal coherence of solid state quasicondensates that evolve in our device above threshold. By fitting the experimental data with a microscopic quantum theory based on a quantum jump approach, we scrutinize the influence of pump power and confinement and find that phonon-mediated transitions are enhanced in the case of a confined structure, in which the modes split into a discrete set. By increasing the pump power beyond the condensation threshold, temporal coherence significantly improves in devices with increased spatial confinement, as revealed in the transition from thermal to coherent statistics of the emitted light.Item Instantaneous radiation from time-varying electric and magnetic dipoles(American Physical Society, 2020-07) Mirmoosa, Mohammad; Ptitcyn, Grigorii; Fleury, R.; Tretiakov, Sergei; Swiss Federal Institute of Technology Lausanne; Sergei Tretiakov Group; Department of Electronics and NanoengineeringRadiation from magnetic and electric dipole moments is a key subject in the theory of electrodynamics. Although people treat the problem thoroughly in the context of the frequency domain, the problem is still not well understood in the context of the time domain especially if dipole moments arbitrarily vary in time under the action of external forces. Here, we scrutinize the instantaneous power radiated by magnetic and electric dipole moments and report findings that are different from the conventional understanding of their instantaneous radiation found in textbooks. In contrast to the traditional far-field approach based on the Poynting vector, our analysis employs a near-field method based on the induced electromotive force, leading to corrective terms that are found to be consistent with time-domain numerical simulations, unlike previously reported expressions. Beyond its theoretical value, this paper may also have significant impact in the field of time-varying metamaterials especially in the study of radiation from subwavelength meta-atoms, scatterers, and emitters that are temporally modulated.Item Metallized Boron-Doped Black Silicon Emitters For Front Contact Solar Cells(2018) von Gastrow, Guillaume; Calle, Eric; Ortega, Pablo; Alcubilla, Ramon; Daniil, Andreana; Stutz, Elias Z.; Fontcuberta i Morral, Anna; Husein, Sebastian; Nietzold, Tara; Bertoni, Mariana; Savin, Hele; Department of Electronics and Nanoengineering; Polytechnic University of Catalonia; Swiss Federal Institute of Technology Lausanne; Arizona State UniversityWe study doping and metallization of black silicon (bSi) boron emitters formed by ion implantation or diffusion. We demonstrate that conformal metal layers can be deposited on bSi by electron beam evaporation. Raman spectroscopy shows that high boron concentrations (4·10 19 cm -3 ) are obtained in bSi by ion implantation, while maintaining emitter saturation current (J 0e ) below 20 fA/cm 2 with Al 2 O 3 passivation. In diffused bSi emitters, doping increases to twice the values of planar substrates, reaching values up to 7·1020 cm -3 . Those doping values allow specific contact resistivities down to (0.3 ± 0.2) mΩ·cm 2 on boron-implanted bSi surfaces with nickel or aluminum contacts.Item Overview of ASDEX Upgrade results(2017-10) Aguiam, D.; Aho-Mantila, L.; Angioni, C.; Arden, N.; Parra, R. Arredondo; Asunta, O.; de Baar, M.; Balden, M.; Behler, K.; Bergmann, A.; Bernardo, J.; Bernert, M.; Beurskens, M.; Biancalani, A.; Bilato, R.; Birkenmeier, G.; Bobkov, V.; Bock, A.; Bogomolov, A.; Bolzonella, T.; Boeswirth, B.; Bottereau, C.; Bottino, A.; van den Brand, H.; Brezinsek, S.; Brida, D.; Brochard, F.; Bruhn, C.; Buchanan, J.; Buhler, A.; Burckhart, A.; Cambon-Silva, D.; Camenen, Y.; Carvalho, P.; Carrasco, G.; Cazzaniga, C.; Carr, M.; Carralero, D.; Casali, L.; Castaldo, C.; Cavedon, M.; Challis, C.; Chankin, A.; Chapman, I.; Clairet, F.; Classen, I.; Coda, S.; Coelho, R.; Coenen, J. W.; Colas, L.; Conway, G.; Costea, S.; Coster, D. P.; Croci, G.; Cseh, G.; Czarnecka, A.; D'Arcangelo, O.; Day, C.; Delogu, R.; de Marne, P.; Denk, S.; Denner, P.; Dibon, M.; D'Inca, R.; Di Siena, A.; Douai, D.; Drenik, A.; Drube, R.; Dunne, M.; Duval, B. P.; Dux, R.; Eich, T.; Elgeti, S.; Engelhardt, K.; Erdos, B.; Erofeev, I.; Esposito, B.; Fable, E.; Faitsch, M.; Fantz, U.; Faugel, H.; Felici, F.; Fietz, S.; Figueredo, A.; Fischer, R.; Ford, O.; Frassinetti, L.; Freethy, S.; Froeschle, M.; Fuchert, G.; Fuchs, J. C.; Fuenfgelder, H.; Galazka, K.; Galdon-Quiroga, J.; Gallo, A.; Gao, Y.; Garavaglia, S.; Garcia-Munoz, M.; Geiger, B.; Cianfarani, C.; Giannone, L.; Giovannozzi, E.; Gleason-Gonzalez, C.; Gloeggler, S.; Gobbin, M.; Goerler, T.; Goodman, T.; Gorini, G.; Gradic, D.; Graeter, A.; Granucci, G.; Greuner, H.; Griener, M.; Groth, M.; Gude, A.; Guenter, S.; Guimarais, L.; Haas, G.; Hakola, A. H.; Ham, C.; Happel, T.; Harrison, J.; Hatch, D.; Hauer, V.; Hayward, T.; Heinemann, B.; Heinzel, S.; Hellsten, T.; Henderson, S.; Hennequin, P.; Herrmann, A.; Heyn, E.; Hitzler, F.; Hobirk, J.; Hoelzl, M.; Hoeschen, T.; Holm, J. H.; Hopf, C.; Hoppe, F.; Horvath, L.; Houben, A.; Huber, A.; Igochine, V.; Ilkei, T.; Ivanova-Stanik, I.; Jacob, W.; Jacobsen, A. S.; Jacquot, J.; Janky, F.; Jardin, A.; Jaulmes, F.; Jenko, F.; Jensen, T.; Joffrin, E.; Kaesemann, C.; Kallenbach, A.; Kalvin, S.; Kantor, M.; Kappatou, A.; Kardaun, O.; Karhunen, J.; Kasilov, S.; Kernbichler, W.; Kim, D.; Kimmig, S.; Kirk, A.; Klingshirn, H. -J.; Koch, F.; Kocsis, G.; Koehn, A.; Kraus, M.; Krieger, K.; Krivska, A.; Kraemr-Flecken, A.; Kurki-Suonio, T.; Kurzan, B.; Lackner, K.; Laggner, F.; Lang, P. T.; Lauber, P.; Lazanyi, N.; Lazaros, A.; Lebschy, A.; Li, L.; Li, M.; Liang, Y.; Lipschultz, B.; Liu, Y.; Lohs, A.; Luhmann, N. C.; Lunt, T.; Lyssoivan, A.; Madsen, J.; Maier, H.; Maj, O.; Mailloux, J.; Maljaars, E.; Manas, P.; Mancini, A.; Manhard, A.; Manso, M. -E.; Mantica, P.; Mantsinen, M.; Manz, P.; Maraschek, M.; Martens, C.; Martin, P.; Marrelli, L.; Martitsch, A.; Mastrostefano, S.; Mayer, A.; Mayer, M.; Mazon, D.; McCarthy, P. J.; McDermott, R.; Meisl, G.; Meister, H.; Medvedeva, A.; Merkel, P.; Merkel, R.; Merle, A.; Mertens, V.; Meshcheriakov, D.; Meyer, H.; Meyer, O.; Miettunen, J.; Milanesio, D.; Mink, F.; Mlynek, A.; Monaco, F.; Moon, C.; Nazikian, R.; Nemes-Czopf, A.; Neu, G.; Neu, R.; Nielsen, A. H.; Nielsen, S. K.; Nikolaeva, V.; Nocente, M.; Noterdaeme, J. -M.; Nowak, S.; Oberkofler, M.; Oberparleiter, M.; Ochoukov, R.; Odstrcil, T.; Olsen, J.; Orain, F.; Palermo, F.; Papp, G.; Perez, I. Paradela; Pautasso, G.; Enzel, F.; Petersson, P.; Pinzon, J.; Piovesan, P.; Piron, C.; Plaum, B.; Ploeckl, B.; Plyusnin, V.; Pokol, G.; Poli, E.; Porte, L.; Potzel, S.; Prisiazhniuk, D.; Puetterich, T.; Ramisch, M.; Rapson, C.; Rasmussen, J.; Raupp, G.; Refy, D.; Reich, M.; Reimold, F.; Ribeiro, T.; Riedl, R.; Rittich, D.; Rocchi, G.; Rodriguez-Ramos, M.; Rohde, V.; Ross, A.; Rott, M.; Rubel, M.; Ryan, D.; Ryter, F.; Saarelma, S.; Salewski, M.; Salmi, A.; Sanchis-Sanchez, L.; Santos, G.; Santos, J.; Sauter, O.; Scarabosio, A.; Schall, G.; Schmid, K.; Schmitz, O.; Schneider, P. A.; Schneller, M.; Schrittwieser, R.; Schubert, M.; Schwarz-Selinger, T.; Schweinzer, J.; Scott, B.; Sehmer, T.; Sertoli, M.; Shabbir, A.; Shalpegin, A.; Shao, L.; Sharapov, S.; Siccinio, M.; Sieglin, B.; Sigalov, A.; Silva, A.; Silva, C.; Simon, P.; Simpson, J.; Snicker, A.; Sommariva, C.; Sozzi, C.; Spolaore, M.; Stejner, M.; Stober, J.; Stobbe, F.; Stroth, U.; Strumberger, E.; Suarez, G.; Sugiyama, K.; Sun, H. -J.; Suttrop, W.; Szepesi, T.; Tal, B.; Tala, T.; Tardini, G.; Tardocchi, M.; Terranova, D.; Tierens, W.; Told, D.; Tudisco, O.; Trevisan, G.; Treutterer, W.; Trier, E.; Tripsky, M.; Valisa, M.; Valovic, M.; Vanovac, B.; Varela, P.; Varoutis, S.; Verdoolaege, G.; Vezinet, D.; Vianello, N.; Vicente, J.; Vierle, T.; Viezzer, E.; von Toussaint, U.; Wagner, D.; Wang, N.; Wang, X.; Weidl, M.; Weiland, M.; White, A. E.; Willensdorfer, M.; Wiringer, B.; Wischmeier, M.; Wolf, R.; Wolfrum, E.; Xiang, L.; Yang, Q.; Yang, Z.; Yu, Q.; Zagorski, R.; Zammuto, I.; Zarzoso, D.; Zhang, W.; van Zeeland, M.; Zehetbauer, T.; Zilker, M.; Zoletnik, S.; Zohm, H.; IST; VTT Technical Research Centre of Finland; Max Planck Inst Astrophys, Max Planck Society; Department of Applied Physics; TEC; JET EFDA, Culham Sci Ctr; Technische Universität München; Consorzio RFX; IRFM; Assoc EURATOM FZJ, Euratom, Julich Research Center, Forschungszentrum Julich, Inst Energy & Climate Res; University of Lorraine; ENEA; Istituto Fisica del Plasma "Piero Caldirola" (IFP-CNR); Swiss Federal Institute of Technology Lausanne; Innsbruck Medical University; Hungarian Academy of Sciences; Institute of Plasma Physics & Laser Microfusion (IFPiLM); Karlsruhe Institute of Technology; Eindhoven University of Technology; Swedish Research Council (VR); General Atomics & Affiliated Companies; University of Sevilla; University of Texas at Austin; Max Planck Comp & Data Facil; Ecole Polytechnique; Hochschule der Medien; Technical University of Denmark; Budapest University of Technology and Economics; University of California at Santa Barbara; School services, SCI; LPP-ERM/KMS EURATOM Association; Vienna University of Technology; Assoc EURATOM Hellen Republ, NCSR Demokritos; IPP; York University; CCFE Fusion Assoc; BSC; Univ Coll Cork UCC; Princeton University; Ghent University; Chinese Acad Sci, Chinese Academy of Sciences, Natl Astron Observ; Department of Radio Science and Engineering; Massachusetts Institute of Technology; Chinese Academy of Sciences; Univ Aix Marseille 1, Centre National de la Recherche Scientifique (CNRS), University of Aix-Marseille, Universite de Provence - Aix-Marseille I, UMR 6098, CNRSThe ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of I-p = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen E-N >= 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.Item Quantifying the Error of Light Transport Algorithms(WILEY-BLACKWELL, 2019-07-01) Celarek, A.; Jakob, W.; Wimmer, M.; Lehtinen, J.; Vienna University of Technology; Swiss Federal Institute of Technology Lausanne; Helsinki Institute for Information Technology (HIIT); Department of Computer ScienceThis paper proposes a new methodology for measuring the error of unbiased physically based rendering algorithms. The current state of the art includes mean squared error (MSE) based metrics and visual comparisons of equal-time renderings of competing algorithms. Neither is satisfying as MSE does not describe behavior and can exhibit significant variance, and visual comparisons are inherently subjective. Our contribution is two-fold: First, we propose to compute many short renderings instead of a single long run and use the short renderings to estimate MSE expectation and variance as well as per-pixel standard deviation. An algorithm that achieves good results in most runs, but with occasional outliers is essentially unreliable, which we wish to quantify numerically. We use per-pixel standard deviation to identify problematic lighting effects of rendering algorithms. The second contribution is the error spectrum ensemble (ESE), a tool for measuring the distribution of error over frequencies. The ESE serves twopurposes: It reveals correlation between pixels and can be used to detect outliers, which offset the amount of error substantially.Item Second-Order Converse for Rate-Limited Common Randomness Generation(IEEE, 2022) Hentila, Henri; Shkel, Yanina; Koivunen, Visa; Dept Signal Process and Acoust; Swiss Federal Institute of Technology LausanneWe employ a recent technique based on a semigroup application of the method of types to improve on a second-order converse for the common randomness (CR) generation problem. The previously known bound lead to a correct second-order asymptotic rate, but incorrect sign on the second-order term for error rates below 1/2. The new bound has both the correct scaling and sign of the second-order term for small enough error rates.Item Temporal Modulation of Bianisotropic Metasurfaces for Unidirectional Wave Amplification(2020-03) Wang, Xuchen; Diaz-Rubio, A.; Asadchy, V.; Ptitcyn, Grigorii; Mirmoosa, M. S.; Tretiakov, Sergei; Department of Electronics and Nanoengineering; Stanford University; Sergei Tretiakov Group; Swiss Federal Institute of Technology LausanneNonreciprocity in time-modulated metasurfaces is normally achieved only when it is combined with with space modulation, using at least two time-varying elements located at different positions in space. In this talk, we present the idea of time-modulated bianisotropic metasurfaces where nonreciprocal wave propagation is realized with time modulation of only a single element. The results show that by uniformly modulating a capacitive sheet mounted on a sub-wavelength dielectric layer, one can obtain strong nonreciprocity and achieve unidirectional wave amplification.Item Towards Building A Framework For Continuing Engineering Education In Higher Education Institutions: A Comparative Study(2023) Gomez Puente, Sonia M.; Smith, Christopher; Urenda Moris, Matias; NØRGAARD, Bente; Heiss, Hans-Ulrich; Caratozzolo, Patricia; Schrey-Niemenmaa, Katriina; Myllymäki, Hanna Riikka; Hadzilacos, Rigas; Eindhoven University of Technology; Glasgow Caledonian University; Uppsala University; Aalborg University; Technical University of Berlin; Tecnológico de Monterrey; Department of Electrical Engineering and Automation; Aalto University Executive Education; Swiss Federal Institute of Technology Lausanne; Reilly, Ger; Murphy, Mike; Nagy, Balazs Vince; Jarvinen, Hannu-MattiContinuing engineering education (CEE) is becoming an attractive notion of continuously enhancing and upgrading the engineering skills required by the Fourth Industrial Revolution. Current developments in science and technology and the challenges to address the United Nations Sustainable Development Goals (UN SDGs) of the 2030 Agenda require updating theoretical knowledge, skills, and specific practical work. Even though higher education institutions (HEIs) can provide CEE or CPD (Continuing Professional Development) within or external to degree programs, CEE focuses on training engineers as lifelong learners to meet societal and industrial needs. A comparative study was conducted among eight universities to analyse the strategies used to provide CEE services at an institutional level. This study aims to investigate approaches and practices in CEE offerings to learn lessons and adjust CEE programs and policies in the HEIs involved in this research. The study followed an adapted version of a Comparative Case Study (CSS) as a suitable framework to map the CEE strategies and approaches of the participating universities. Preliminary results indicated differences in the organisational structures, e.g., traditional courses within existing programs. At the same time, other institutions provide flexible mechanisms such as short courses, modules, or micro-credential activities leading to qualifications. Similarities are found in institutional policies aiming at developing postgraduate programs aligned to industry demands. This study reflects the importance of learning programs as resources provided by HEIs applying a framework for engineering education and the engineers’ further professional development.Item Undoped p-type GaN1-xSbx alloys(2016-12-19) Segercrantz, N.; Baumgartner, Y.; Ting, M.; Yu, K. M.; Mao, S. S.; Sarney, W. L.; Svensson, S. P.; Walukiewicz, W.; Department of Applied Physics; Swiss Federal Institute of Technology Lausanne; University of California Berkeley; City University of Hong Kong; United States Army Research Laboratory; Lawrence Berkeley National LaboratoryWe report p-type behavior for undoped GaN1-xSbx alloys with x ≥ 0.06 grown by molecular beam epitaxy at low temperatures (≤400 °C). Rapid thermal annealing of the GaN1-xSbx films at temperatures >400 °C is shown to generate hole concentrations greater than 1019 cm-3, an order of magnitude higher than typical p-type GaN achieved by Mg doping. The p-type conductivity is attributed to a large upward shift of the valence band edge resulting from the band anticrossing interaction between localized Sb levels and extended states of the host matrix.
