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1. Layered liquid crystal elastomer actuators

Author: Tyler Guin, Michael J. Settle, Benjamin A. Kowalski, Anesia D. Auguste, Richard V. Beblo, Gregory W. Reich, and Timothy J. White
Subjects: Science
Abstract: Liquid crystalline elastomers (LCE) exhibit shape transformation when subjected to various stimuli, but the achievable thickness of LCE films is limited. Here the authors demonstrate arbitrarily thick LCE films that are continuous in composition and maintain the director orientation, prescribed into the material.
Published: 2018
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2. Robust Optimal Design and Control of a Maneuvering Morphing Airfoil

Author: Eliot S. Rudnick-Cohen, Joshua D. Hodson, Gregory W. Reich, Alexander M. Pankonien, and Philip S. Beran
Subjects: Aerospace Engineering
Published: 2022
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3. Lies, Half-Truths, and More Lies: The Truth Behind 250 'Facts' You Learned in School (and Elsewhere)

Author: Herb W. Reich
Published: 2017

4. Towards the Optimal Partitioning of Additive Manufactured Multi-Material Models

Author: Asa E. Palmer, Alexander M. Pankonien, Gregory W. Reich, Eliot S. Rudnick-Cohen, and Markus P. Rumpfkeil
Published: 2022
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5. A Global View on Star Formation: The GLOSTAR Galactic Plane Survey V. 6.7 GHz Methanol Maser Catalogue

Author: H. Nguyen, M. R. Rugel, C. Murugeshan, K. M. Menten, A. Brunthaler, J. S. Urquhart, R. Dokara, S. A. Dzib, Y. Gong, S. Khan, S.-N. X. Medina, G. N. Ortiz-León, W. Reich, F. Wyrowski, A. Y. Yang, H. Beuther, W. D. Cotton, and J. D. Pandian
Subjects: Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract: Class II methanol (CH$_{3}$OH) masers are amongst the clearest signposts of recent high-mass star formation (HMSF). A complete catalogue outlines the distribution of star formation in the Galaxy, the number of young star-forming cores, and the physical conditions of their environment. The Global View on Star Formation (GLOSTAR) survey, which is a blind survey in the radio regime of 4$-$8 GHz, maps the Galactic mid-plane in the radio continuum, 6.7 GHz methanol line, the 4.8 GHz formaldehyde line, and several radio recombination lines. We present the analysis of the observations of the 6.7 GHz CH$_{3}$OH maser transition using data from the D-configuration of the Very Large Array (VLA). We analyse the data covering Galactic longitudes from $-2^{\circ}< l, Accepted in A&A July 18, 2022
Published: 2022
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6. Sub-arcsecond imaging with the International LOFAR Telescope II. Completion of the LOFAR Long-Baseline Calibrator Survey

Author: G. K. Miley, Annalisa Bonafede, M. P. van Haarlem, Jochen Eislöffel, John McKean, P. C. G. van Dijk, M. A. Garrett, B. Ciardi, R. Blaauw, E. Jütte, Harvey Butcher, O. Wucknitz, Luitje Koopmans, Oleg Smirnov, M. Pandey-Pommier, Pietro Zucca, Joseph R. Callingham, S. Mooney, R. J. van Weeren, A. Nelles, Antonia Rowlinson, W. Reich, Heino Falcke, S. Duscha, Rajan Chhetri, Emanuela Orrú, G. Mann, Dominik J. Schwarz, Michiel A. Brentjens, P. Zarka, M. Ruiter, Hanna Rothkaehl, Kaspars Prūsis, Ralph A. M. J. Wijers, S. Badole, Jean-Mathias Griessmeier, P. Maat, Neal Jackson, Marco Iacobelli, Jeremy J. Harwood, Andrzej Krankowski, M. J. Norden, Vishambhar Pandey, A. J. van der Horst, John Morgan, F. Sweijen, Adam Deller, George Heald, S. Damstra, Martin J. Hardcastle, Mark J. Bentum, Ashish Asgekar, Leah K. Morabito, A. W. Gunst, M. Tagger, A. Shulevski, C. Vocks, A. Drabent, Javier Moldon, A. H. W. M. Coolen, M. Paas, Atvars Nikolajevs, W. N. Brouw, J. Sluman, Roberto Pizzo, Marcus Brüggen, Henk Mulder, Matthias Hoeft, F. de Gasperin, I. M. Avruch, J. A. Zensus, Arthur Corstanje, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), European Commission, Ministerio de Ciencia e Innovación (España), Netherlands Organization for Scientific Research, UK Research and Innovation, Chinese Academy of Sciences, High Energy Astrophys. & Astropart. Phys (API, FNWI), Kapteyn Astronomical Institute, Center for Wireless Technology Eindhoven, and EM for Radio Science Lab
Subjects: active -Radio continuum, active [Galaxies], Radio galaxy, galaxies -Atmospheric physics, Astronomy, media_common.quotation_subject, FOS: Physical sciences, Flux, Murchison Widefield Array, ionosphere, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, Interplanetary scintillation, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, Remote sensing, media_common, Physics, Spectral index, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Radio lines: galaxies, Astrophysics::Instrumentation and Methods for Astrophysics, interferometers [Instrumentation], Astronomy and Astrophysics, Quasar, LOFAR, Galaxies: active, interferometers -Techniques, Astrophysics - Astrophysics of Galaxies, galaxies [Radio lines], Space and Planetary Science, Sky, [SDU]Sciences of the Universe [physics], Instrumentation: interferometers, Astrophysics of Galaxies (astro-ph.GA), Techniques: interferometric, interferometric [Techniques], interferometric -Surveys -Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: Full list of authors: Jackson, N.; Badole, S.; Morgan, J.; Chhetri, R.; Prūsis, K.; Nikolajevs, A.; Morabito, L.; Brentjens, M.; Sweijen, F.; Iacobelli, M.; Orrù, E.; Sluman, J.; Blaauw, R.; Mulder, H.; van Dijk, P.; Mooney, S.; Deller, A.; Moldon, J.; Callingham, J. R.; Harwood, J.; Hardcastle, M.; Heald, G.; Drabent, A.; McKean, J. P.; Asgekar, A.; Avruch, I. M.; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Coolen, A.; Corstanje, A.; Damstra, S.; Duscha, S.; Eislöffel, J.; Falcke, H.; Garrett, M.; de Gasperin, F.; Griessmeier, J. -M.; Gunst, A. W.; van Haarlem, M. P.; Hoeft, M.; van der Horst, A. J.; Jütte, E.; Koopmans, L. V. E.; Krankowski, A.; Maat, P.; Mann, G.; Miley, G. K.; Nelles, A.; Norden, M.; Paas, M.; Pandey, V. N.; Pandey-Pommier, M.; Pizzo, R. F.; Reich, W.; Rothkaehl, H.; Rowlinson, A.; Ruiter, M.; Shulevski, A.; Schwarz, D. J.; Smirnov, O.; Tagger, M.; Vocks, C.; van Weeren, R. J.; Wijers, R.; Wucknitz, O.; Zarka, P.; Zensus, J. A.; Zucca, P., The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, building on the preliminary analysis published in 2016 which covered approximately half the survey area. The final catalogue consists of 30 006 observations of 24 713 sources in the northern sky, selected for a combination of high low-frequency radio flux density and flat spectral index using existing surveys (WENSS, NVSS, VLSS, and MSSS). Approximately one calibrator per square degree, suitable for calibration of ≥200 km baselines is identified by the detection of compact flux density, for declinations north of 30° and away from the Galactic plane, with a considerably lower density south of this point due to relative difficulty in selecting flat-spectrum candidate sources in this area of the sky. The catalogue contains indicators of degree of correlated flux on baselines between the Dutch core and each of the international stations, involving a maximum baseline length of nearly 2000 km, for all of the observations. Use of the VLBA calibrator list, together with statistical arguments by comparison with flux densities from lower-resolution catalogues, allow us to establish a rough flux density scale for the LBCS observations, so that LBCS statistics can be used to estimate compact flux densities on scales between 300 mas and 2′′, for sources observed in the survey. The survey is used to estimate the phase coherence time of the ionosphere for the LOFAR international baselines, with median phase coherence times of about 2 min varying by a few tens of percent between theshortest and longest baselines. The LBCS can be used to assess the structures of point sources in lower-resolution surveys, with significant reductions in the degree of coherence in these sources on scales between 2′′ and 300 mas. The LBCS survey sources show a greater incidence of compact flux density in quasars than in radio galaxies, consistent with unified schemes of radio sources. Comparison with samples of sources from interplanetary scintillation (IPS) studies with the Murchison Widefield Array shows consistent patterns of detection of compact structure in sources observed both interferometrically with LOFAR and using IPS. © ESO 2022., Support for the operation of the MWA is provided by the Australian Government (NCRIS), under a contract to Curtin University administered by Astronomy Australia Limited. We acknowledge the Pawsey Supercomputing Centre which is supported by the Western Australian and Australian Governments. A.D. acknowledges support by the BMBF Verbundforschung under the grant 052020. L.K.M. is grateful for support from the UKRI Future Leaders Fellowship (grant MR/T042842/1). J. Moldón acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and from the grant RTI2018-096228-B-C31 (MICIU/FEDER, EU). J.P.M. acknowledges support from the Netherlands Organization for Scientific Research (NWO, project number 629.001.023) and the Chinese Academy of Sciences (CAS, project number 114A11KYSB20170054).
Published: 2022
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7. Filamentary structures of ionized gas in Cygnus X

Author: K. L. Emig, G. J. White, P. Salas, R. L. Karim, R. J. van Weeren, P. J. Teuben, A. Zavagno, P. Chiu, M. Haverkorn, J. B. R. Oonk, E. Orrú, I. M. Polderman, W. Reich, H. J. A. Röttgering, A. G. G. M. Tielens, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: Cygnus OB2, techniques, HII regions, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, open clusters and associations, ISM, HII regions, ISM, FOS: Physical sciences, techniques: image processing, Astrophysics::Cosmology and Extragalactic Astrophysics, radio continuum, image processing, Astrophysics - Astrophysics of Galaxies, Astrophysics::Solar and Stellar Astrophysics, open clusters and associations: individual: Cygnus OB2, individual, Cygnus OB2, Astrophysics::Galaxy Astrophysics, ISM, ISM: general, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, image processing, radio continuum: ISM, Space and Planetary Science, [SDU]Sciences of the Universe [physics], general, Astrophysics of Galaxies (astro-ph.GA), techniques, general, open clusters and associations
Abstract: Ionized gas probes the influence of massive stars on their environment. The Cygnus X region (d~1.5 kpc) is one of the most massive star forming complexes in our Galaxy, in which the Cyg OB2 association (age of 3-5 Myr and stellar mass $2 \times 10^{4}$ M$_{\odot}$) has a dominant influence. We observe the Cygnus X region at 148 MHz using the Low Frequency Array (LOFAR) and take into account short-spacing information during image deconvolution. Together with data from the Canadian Galactic Plane Survey, we investigate the morphology, distribution, and physical conditions of low-density ionized gas in a $4^{\circ} \times 4^{\circ}$ (100 pc $\times$ 100 pc) region at a resolution of 2' (0.9 pc). The Galactic radio emission in the region analyzed is almost entirely thermal (free-free) at 148 MHz, with emission measures of $10^3 < EM~{\rm[pc~cm^{-6}]} < 10^6$. As filamentary structure is a prominent feature of the emission, we use DisPerSE and FilChap to identify filamentary ridges and characterize their radial ($EM$) profiles. The distribution of radial profiles has a characteristic width of 4.3 pc and a power-law distribution ($β= -1.8 \pm 0.1$) in peak $EM$ down to our completeness limit of 4200 pc cm$^{-6}$. The electron densities of the filamentary structure range from $10 < n_e~{\rm[cm^{-3}]} < 400$ with a median value of 35 cm$^{-3}$, remarkably similar to [N II] surveys of ionized gas. Cyg OB2 may ionize at most two-thirds of the total ionized gas and the ionized gas in filaments. More than half of the filamentary structures are likely photoevaporating surfaces flowing into a surrounding diffuse (~5 cm$^{-3}$) medium. However, this is likely not the case for all ionized gas ridges. A characteristic width in the distribution of ionized gas points to the stellar winds of Cyg OB2 creating a fraction of the ionized filaments through swept-up ionized gas or dissipated turbulence., 19 pages, 14 figures, 1 table; accepted for publication in A&A
Published: 2022
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8. A global view on star formation: The GLOSTAR Galactic plane survey

Author: R. Dokara, Y. Gong, W. Reich, M. R. Rugel, A. Brunthaler, K. M. Menten, W. D. Cotton, S. A. Dzib, S. Khan, S.-N. X. Medina, H. Nguyen, G. N. Ortiz-León, J. S. Urquhart, F. Wyrowski, A. Y. Yang, L. D. Anderson, H. Beuther, T. Csengeri, P. Müller, J. Ott, J. D. Pandian, and N. Roy
Subjects: Space and Planetary Science, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: Context. While over 1000 supernova remnants (SNRs) are estimated to exist in the Milky Way, only less than 400 have been found to date. In the context of this apparent deficiency, more than 150 SNR candidates were recently identified in the D-configuration Very Large Array (VLA-D) continuum images of the 4--8 GHz global view on star formation (GLOSTAR) survey, in the Galactic longitude range $-2^\circ, Comment: To be published in A&A. 21 pages, 15 figures
Published: 2023
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9. LOFAR in Germany

Author: W. Reich
Subjects: Engineering (General). Civil engineering (General), TA1-2040
Abstract: The LOw Frequency ARray – LOFAR – is a new fully digital radio telescope designed for frequencies between 30 MHz and 240 MHz centered in the Netherlands. In May 2006 ten German institutes formed the German LOng Wavelength consortium – GLOW – to coordinate its contributions and scientific interests to the LOFAR project. The first LOFAR station CS1 was installed in summer 2006 near Exloo/Netherlands. The second station IS-G1 is presently been placed in the immediate vicinity of the Effelsberg 100-m radio telescope near Bad Münstereifel/Germany. This contribution briefly describes the basic properties and aims of LOFAR, the aims of the GLOW consortium and the actual activities to install a LOFAR station at the Effelsberg site.
Published: 2007

10. Handbook of Adult Resilience

Author: John W. Reich, Alex J. Zautra, John Stuart Hall
Published: 2010

11. Development and validation of a genetic L-System programming framework for topology optimization of multifunctional structures

Author: Darren J. Hartl, Gregory W. Reich, Philip S. Beran, and Brent R. Bielefeldt
Subjects: Theoretical computer science, Process (engineering), Computer science, Mechanical Engineering, Topology optimization, Structure (category theory), 02 engineering and technology, computer.software_genre, Network topology, 01 natural sciences, Computer Science Applications, 010101 applied mathematics, Software framework, 020303 mechanical engineering & transports, Development (topology), 0203 mechanical engineering, Modeling and Simulation, Encoding (memory), General Materials Science, 0101 mathematics, L-system, computer, Civil and Structural Engineering
Abstract: When considering the complex problem of developing new multifunctional structures, it is essential to narrow the vast design space and reduce the infinite number of possible solutions to a finite subset of feasible designs. Nature provides examples of ramified, or branched, topologies that form non-intuitive solutions to various structural design problems. This work focuses on the development of a bio-inspired topology optimization framework that couples genetic algorithms with a parallel rewriting system known as a Lindenmayer System (or L-System), which acts as an analogy to the evolutionary process and formalizes the encoding of a 2-D structure. Example design problems and the solutions determined using this novel framework are presented and compared to ideal solutions, where it is shown that a family of branched solutions allowed to evolve over generations can eventually arrive at effective multifunctional structures. Select designs from each example problem are also thickened into 3-D bodies, which are assessed experimentally via fully functional prototypes, demonstrating that the L-System framework is capable of generating realistic solutions for multifunctional structure development.
Published: 2019
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12. Multifunctional topology optimization of strain-sensing nanocomposite beam structures

Author: Mayuresh J. Patil, Ryan Seifert, Gary D. Seidel, and Gregory W. Reich
Subjects: Control and Optimization, Materials science, Topology optimization, Micromechanics, Computer Graphics and Computer-Aided Design, Piezoresistive effect, Finite element method, Computer Science Applications, Strain energy, Control and Systems Engineering, Volume fraction, Composite material, Software, Beam (structure), Neutral axis
Abstract: Controlling volume fractions of nanoparticles in a matrix can have a substantial influence on composite performance. This paper presents a multi-start topology optimization algorithm that designs nanocomposite structures for objectives pertaining to stiffness and strain sensing. Local effective properties are obtained by controlling local volume fractions of carbon nanotubes (CNTs) in an epoxy matrix, which are assumed to be well dispersed and randomly oriented. Local Young’s modulus, conductivity, and piezoresistive constant drive the global objectives of strain energy and resistance change. Strain energy is obtained via a modified solution of Euler-Bernoulli equations and resistance change is obtained via solution of a bilinear quadrilateral finite element problem. The optimization uses a two-step restart method in which Pareto points from the first step are used as starting conditions in the second step. An efficient method for obtaining analytic sensitivities of the objective functions is presented. The method is used to solve a set of example problems pertaining to the design of a composite beam in bending. The results show that the strain energy may be optimized by placing high volume-fraction CNT elements away from the neutral axis. Resistance change is optimized through a combination of shifting the neutral axis, formation of conductive paths between electrodes, and asymmetric distribution of highly piezoresistive elements. Results also show that the strain energy is governed by the volume fraction constraint and the resistance change is dependent on a combination of the volume fraction constraint and the boundary electrode location.
Published: 2019
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13. A global view on star formation: The GLOSTAR Galactic Plane Survey. I. Overview and first results for the Galactic longitude range 28{\deg} < l < 36{\deg}

Author: H. Nguyen, S.-N. X. Medina, Karl M. Menten, S. J. Billington, W. Reich, J. D. Pandian, Gisela N. Ortiz-León, C. Murugeshan, Rohit Dokara, Timea Csengeri, Friedrich Wyrowski, James Urquhart, Carlos Carrasco-González, Y. Gong, Peter Müller, Michael Rugel, Andreas Brunthaler, S. A. Dzib, Benjamin Winkel, W. D. Cotton, A. Y. Yang, Henrik Beuther, and Nirupam Roy
Subjects: Physics, 010308 nuclear & particles physics, Star formation, Milky Way, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic plane, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, law.invention, Telescope, Jansky, Space and Planetary Science, law, 0103 physical sciences, QB460, Maser, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Data reduction
Abstract: Surveys of the Milky Way at various wavelengths have changed our view of star formation in our Galaxy considerably in recent years. In this paper we give an overview of the GLOSTAR survey, a new survey covering large parts (145 square degrees) of the northern Galactic plane using the Karl G. Jansky Very Large Array (JVLA) in the frequency range 4-8 GHz and the Effelsberg 100-m telescope. This provides for the first time a radio survey covering all angular scales down to 1.5 arcsecond, similar to complementary near-IR and mid-IR galactic plane surveys. We outline the main goals of the survey and give a detailed description of the observations and the data reduction strategy. In our observations we covered the radio continuum in full polarization, as well as the 6.7 GHz methanol maser line, the 4.8~GHz formaldehyde line, and seven radio recombination lines. The observations were conducted in the most compact D configuration of the VLA and in the more extended B configuration. This yielded spatial resolutions of 18" and 1.5" for the two configurations, respectively. We also combined the D configuration images with the Effelsberg 100-m data to provide zero spacing information, and we jointly imaged the D- and B-configuration data for optimal sensitivity of the intermediate spatial ranges. Here we show selected results for the first part of the survey, covering the range of 28 deg, Comment: 18 pages, 15 figures, accepted by Astronomy & Astrophysics (A&A), data available via https://glostar.mpifr-bonn.mpg.de
Published: 2021

14. A Method for Capturing Structural Behavior Variations in the Realization of Optimized Graph-Based Topologies for a Morphing Airfoil

Author: Alexander M. Pankonien, Asa E. Palmer, Eliot Rudnick-Cohen, Gregory W. Reich, and Markus P. Rumpfkeil
Subjects: Airfoil, Morphing, Computer science, Graph based, Network topology, Topology, Realization (systems)
Published: 2021
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15. Erratum 'The Global Magneto-Ionic Medium Survey: A Faraday Depth Survey of the Northern Sky Covering 1280–1750 MHz' (2021, AJ, 162, 35)

Author: J. L. Han, W. Reich, M. Wolleben, Roland Kothes, A. Ordog, Jo-Anne Brown, Bryan Gaensler, T. L. Landecker, Ettore Carretti, A. D. Gray, Marijke Haverkorn, Jennifer West, D. McConnell, John M. Dickey, Alec J. M. Thomson, Kevin A. Douglas, Alex S. Hill, A. R. Taylor, J. P. Leahy, and Naomi McClure-Griffiths
Subjects: Physics, business.industry, media_common.quotation_subject, Astronomy, Ionic bonding, Astronomy and Astrophysics, law.invention, Optics, Space and Planetary Science, law, Sky, Faraday cage, business, Magneto, media_common
Abstract: Contains fulltext : 237995.pdf (Publisher’s version ) (Closed access)
Published: 2021
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16. Aerodynamic Parameter Prediction via Artificial Hair Sensors with Signal Power in Turbulent Flow

Author: Kaman Thapa Magar, Gregory W. Reich, Alexander M. Pankonien, and Richard V. Beblo
Subjects: Physics, 020301 aerospace & aeronautics, Lift coefficient, Turbulence, Acoustics, Computer Science::Neural and Evolutionary Computation, Flow (psychology), ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Aerospace Engineering, 02 engineering and technology, Aerodynamics, 01 natural sciences, Signal, 010305 fluids & plasmas, Physics::Fluid Dynamics, Lift (force), Moment (mathematics), Boundary layer, 0203 mechanical engineering, 0103 physical sciences, ComputingMethodologies_COMPUTERGRAPHICS
Abstract: Spatiotemporal surface flow information obtained from distributed arrays of bioinspired hair sensors are capable of predicting the real-time aerodynamic parameters (i.e., lift, moment, angle of att...
Published: 2019
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17. Robust Optimal Design and Control of a Morphing Unmanned Aerial Vehicle (UAV) Airfoil for a Range of Flight Maneuvers

Author: Alexander M. Pankonien, Gregory W. Reich, Philip S. Beran, Joshua D. Hodson, and Eliot Rudnick-Cohen
Subjects: Airfoil, Optimal design, Morphing, Control theory, Computer science, Range (aeronautics)
Published: 2020
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18. A Radio Continuum and Polarisation Study of the pulsar wind nebula CTB87 (G74.9+1.2)

Author: Patricia Reich, Benson Guest, E. Fürst, Samar Safi-Harb, Roland Kothes, and W. Reich
Subjects: 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, magnetic fields, Stellar-wind bubble, 01 natural sciences, Pulsar wind nebula, Radio telescope, 0103 physical sciences, Ejecta, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants, 0105 earth and related environmental sciences, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), polarization, Solar mass, ISM: individual objects: CTB 87, Molecular cloud, Astronomy and Astrophysics, Galactic plane, Supernova, Space and Planetary Science, ISM: magnetic fields, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present radio continuum and linear polarisation observations of the pulsar wind nebula CTB87 (G74.9+1.2) with the Effelsberg 100-m radio telescope between 4.75 and 32 GHz. An analysis of these new data including archived low-frequency observations at 1420 MHz and 408 MHz from the Canadian Galactic Plane Survey shows that CTB87 consists of two distinct emission components: a compact kidney-shaped component, 14 pc x 8.5 pc (7.8' x 4.8') in size and a larger diffuse, spherical and centrally peaked component of about 30 pc (17') in diameter. The kidney-shaped component with a much steeper radio continuum spectrum is highly linearly polarised and likely represents a relic pulsar wind nebula. The diffuse component represents the undisturbed part of the PWN expanding inside a cavity or stellar wind bubble. The previously reported spectral break above 10 GHz is likely the result of missing large-scale emission and insufficient sensitivity of the high-frequency radio continuum observations. The simulation of the system's evolution yields an age of about 18,000 years as the result of a type II supernova explosion with an ejecta mass of about 12 solar masses and an explosion energy of about 7 x 10^50 erg. We also found evidence for a radio shell in our polarisation data which represents the blast wave that entered the molecular cloud complex at a radius of about 13 pc., 17 pages, 15 figures, 5 tables, MNRAS, accepted for publication
Published: 2020

19. Multi-Material Printed Wind-Tunnel Flutter Model

Author: Gregory W. Reich and Alexander M. Pankonien
Subjects: 020301 aerospace & aeronautics, Wing, business.industry, Flight vehicle, Multi material, Aerospace Engineering, 02 engineering and technology, Structural engineering, 01 natural sciences, Instability, 010305 fluids & plasmas, 0203 mechanical engineering, Flight envelope, 0103 physical sciences, Flutter, Wingtip device, business, Geology, Wind tunnel
Abstract: Flying-wing aircraft, typified by the X-56A, experience flutter due to both an instability inherent to tailless configurations and the necessity for aerodynamically efficient high-aspect-ratio wing...
Published: 2018
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20. INVESTIGATION OF FOLD-DEPENDENT BEHAVIOR IN AN ORIGAMI-INSPIRED FSS UNDER NORMAL INCIDENCE

Author: Philip R. Buskohl, Deanna Sessions, Kazuko Fuchi, Gregory W. Reich, Steven R. Seiler, and Gregory H. Huff, David Grayson, Sumana Pallampati, and Giorgio Bazzan
Subjects: Physics, Nuclear magnetic resonance, Topology optimization, 0202 electrical engineering, electronic engineering, information engineering, 020206 networking & telecommunications, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, Condensed Matter Physics, Polarization (waves), Frequency agility, Electronic, Optical and Magnetic Materials
Published: 2018
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21. Planform Design and Optimization of Morphing Aircraft

Author: Jason Y. Kao, Scott Burton, Gregory W. Reich, Daniel L. Clark, and Trenton White
Subjects: Morphing, business.industry, Computer science, Structural engineering, business, Planform
Published: 2020
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22. Air-Racer Design Exploration using Latin Hypercube and Genetic Algorithm Methods

Author: Trenton White, Jason Y. Kao, Gregory W. Reich, Raymond M. Kolonay, and Scott A. Burton
Subjects: Theoretical computer science, Latin hypercube sampling, Computer science, Design exploration, Genetic algorithm
Published: 2020
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23. LOFAR 144-MHz follow-up observations of GW170817

Author: Oleg Smirnov, Martin J. Hardcastle, P. Zarka, Adam Stewart, H. Paas, D. Carbone, P. Maat, Dominik J. Schwarz, M. C. Toribio, David A. Nichols, G. Mann, Rudy Wijnands, A. J. van der Horst, Evan Keane, H. J. A. Röttgering, Olaf Wucknitz, C. Tasse, T. Muñoz-Darias, Henk Mulder, M. H. D. van der Wiel, Kenta Hotokezaka, M. P. van Haarlem, Stephane Corbel, J. B. R. Oonk, S. ter Veen, A. W. Gunst, W. N. Brouw, Casey J. Law, M. Iacobelli, K. Gourdji, Samaya Nissanke, J. W. Broderick, Timothy W. Shimwell, R. Pekal, Rob Fender, W. Reich, James M. Anderson, Matthias Hoeft, Anna Nelles, R. Blaauw, Luitje Koopmans, J. van Leeuwen, Aleksandar Shulevski, R. J. van Weeren, Pietro Zucca, Marian Soida, Martin Bell, Ralph A. M. J. Wijers, Vanessa A. Moss, M. Pandey-Pommier, Thomas M. O. Franzen, Antonia Rowlinson, Anjali A. A. Piette, S. Duscha, Richard Fallows, M. A. Garrett, Peter G. Jonker, Mark J. Bentum, J.-M. Grießmeier, M. de Vos, B. Ciardi, Jörg R. Hörandel, E. Jütte, C. Vocks, M. Serylak, Andrzej Krankowski, Marcus Brüggen, Jochen Eislöffel, M. Pietka, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), High Energy Astrophys. & Astropart. Phys (API, FNWI), Astroparticle Physics (IHEF, IoP, FNWI), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Astronomy, and Kapteyn Astronomical Institute
Subjects: Astronomy, FOS: Physical sciences, Binary number, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Radio spectrum, stars: neutron, neutron [stars], 0201 Astronomical and Space Sciences, 0103 physical sciences, 14. Life underwater, Center frequency, 010306 general physics, stars [radio continuum], 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [PHYS]Physics [physics], Spectral index, Gravitational wave, Astronomy and Astrophysics, LOFAR, Afterglow, Neutron star, gravitational waves, Space and Planetary Science, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], radio continuum: stars
Abstract: We present low-radio-frequency follow-up observations of AT 2017gfo, the electromagnetic counterpart of GW170817, which was the first binary neutron star merger to be detected by Advanced LIGO-Virgo. These data, with a central frequency of 144 MHz, were obtained with LOFAR, the Low-Frequency Array. The maximum elevation of the target is just 13.7 degrees when observed with LOFAR, making our observations particularly challenging to calibrate and significantly limiting the achievable sensitivity. On time-scales of 130-138 and 371-374 days after the merger event, we obtain 3$\sigma$ upper limits for the afterglow component of 6.6 and 19.5 mJy beam$^{-1}$, respectively. Using our best upper limit and previously published, contemporaneous higher-frequency radio data, we place a limit on any potential steepening of the radio spectrum between 610 and 144 MHz: the two-point spectral index $\alpha^{610}_{144} \gtrsim -2.5$. We also show that LOFAR can detect the afterglows of future binary neutron star merger events occurring at more favourable elevations., Comment: 9 pages, 2 figures, accepted for publication in MNRAS
Published: 2020
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24. Cassiopeia A, Cygnus A, Taurus A, and Virgo A at ultra-low radio frequencies

Author: F. de Gasperin, J. Vink, J. P. McKean, A. Asgekar, I. Avruch, M. J. Bentum, R. Blaauw, A. Bonafede, J. W. Broderick, M. Brüggen, F. Breitling, W. N. Brouw, H. R. Butcher, B. Ciardi, V. Cuciti, M. de Vos, S. Duscha, J. Eislöffel, D. Engels, R. A. Fallows, T. M. O. Franzen, M. A. Garrett, A. W. Gunst, J. Hörandel, G. Heald, M. Hoeft, M. Iacobelli, L. V. E. Koopmans, A. Krankowski, P. Maat, G. Mann, M. Mevius, G. Miley, R. Morganti, A. Nelles, M. J. Norden, A. R. Offringa, E. Orrú, H. Paas, V. N. Pandey, M. Pandey-Pommier, R. Pekal, R. Pizzo, W. Reich, A. Rowlinson, H. J. A. Rottgering, D. J. Schwarz, A. Shulevski, O. Smirnov, C. Sobey, M. Soida, M. Steinmetz, M. Tagger, M. C. Toribio, A. van Ardenne, A. J. van der Horst, M. P. van Haarlem, R. J. van Weeren, C. Vocks, O. Wucknitz, P. Zarka, P. Zucca, Astronomy, Kapteyn Astronomical Institute, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), De Gasperin F., Vink J., McKean J.P., Asgekar A., Avruch I., Bentum M.J., Blaauw R., Bonafede A., Broderick J.W., Bruggen M., Breitling F., Brouw W.N., Butcher H.R., Ciardi B., Cuciti V., De Vos M., Duscha S., Eisloffel J., Engels D., Fallows R.A., Franzen T.M.O., Garrett M.A., Gunst A.W., Horandel J., Heald G., Hoeft M., Iacobelli M., Koopmans L.V.E., Krankowski A., Maat P., Mann G., Mevius M., Miley G., Morganti R., Nelles A., Norden M.J., Offringa A.R., Orru E., Paas H., Pandey V.N., Pandey-Pommier M., Pekal R., Pizzo R., Reich W., Rowlinson A., Rottgering H.J.A., Schwarz D.J., Shulevski A., Smirnov O., Sobey C., Soida M., Steinmetz M., Tagger M., Toribio M.C., Van Ardenne A., Van Der Horst A.J., Van Haarlem M.P., Van Weeren R.J., Vocks C., Wucknitz O., Zarka P., Zucca P., High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: Astronomy, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, radio continuum: general, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, radio continuum, law.invention, Telescope, law, 0103 physical sciences, Angular resolution, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Surface brightness, 010306 general physics, Cygnus A, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, High Energy Astrophysical Phenomena (astro-ph.HE), [PHYS]Physics [physics], Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, LOFAR, Astrophysics - Astrophysics of Galaxies, interferometric [techniques], Cassiopeia A, techniques: interferometric, 13. Climate action, Space and Planetary Science, Sky, general, Astrophysics of Galaxies (astro-ph.GA), interferometric, ddc:520, general [radio continuum], Radio frequency, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], techniques, general [ontinuum]
Abstract: The four persistent radio sources in the northern sky with the highest flux density at metre wavelengths are Cassiopeia A, Cygnus A, Taurus A, and Virgo A; collectively they are called the A-team. Their flux densities at ultra-low frequencies (, 7 pages, 2 figures, accepted A&A, online data on A&A website
Published: 2020
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25. Graph-Based Interpretation of L-System Encodings Toward Aeroelastic Topology Optimization of a Morphing Airfoil in Supersonic Flow

Author: Darren J. Hartl, Joshua D. Hodson, Alexander M. Pankonien, Brent R. Bielefeldt, Gregory W. Reich, Joshua D. Deaton, and Philip S. Beran
Subjects: Airfoil, Morphing, Computer science, Topology optimization, Topology (electrical circuits), L-system, Topology, Aeroelasticity, Choked flow, Interpretation (model theory)
Abstract: This work details the preliminary design of a morphing airfoil in supersonic flow using evolutionary design principles. The structural topology of the airfoil includes a fixed outer mold line, fixed spars, and designable internal stiffeners and actuators. The designable components are generated using a bio-inspired model known as a Lindenmayer System (L-System), which encodes design variables and governs the development of a structural topology when coupled with an interpretation algorithm. Here, we utilize a graph-based interpretation scheme known as Spatial Interpretation for the Development of Reconfigurable Structures (SPIDRS), which has been shown to effectively explore the mechanism design space using a limited number of design variables. The optimization process behind this preliminary design problem is discussed, and optimal airfoil topologies capable of meeting specified aerodynamic performance criteria are presented in hopes of gaining a better understanding of how actuation systems could be integrated into the next generation of aircraft.
Published: 2019
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26. A large light-mass component of cosmic rays at 10(17)-10(17.5) electronvolts from radio observations

Author: Vishambhar Pandey, D. D. Mulcahy, M. A. Garrett, J. van Leeuwen, Tim Hassall, Adam Deller, Harvey Butcher, D. Engels, H. Paas, John Conway, J. E. Enriquez, A. I. F. Stewart, M. Pandey-Pommier, Matthias Steinmetz, Rob Fender, B. Ciardi, M. Pietka, E. Juette, G. van Diepen, P. N. Best, M. C. Toribio, A. Horneffer, Chiara Ferrari, M. P. van Haarlem, S. Duscha, Mark J. Bentum, Stefan J. Wijnholds, Jochen Eislöffel, Sarod Yatawatta, Emanuela Orrú, M. Kuniyoshi, Michael Kramer, Anna Nelles, C. Vogt, R. J. van Weeren, Martin Bell, Maaijke Mevius, John D. Swinbank, P. Maat, Matthias Hoeft, M. J. Norden, Pim Schellart, D. McKay-Bukowski, J. A. Zensus, John McKean, Dominik J. Schwarz, Richard Fallows, Aris Karastergiou, Ph. Zarka, V. I. Kondratiev, T. N. G. Trinh, Stijn Buitink, Heino Falcke, Michael W. Wise, Jörg P. Rachen, Benjamin Stappers, Jason W. T. Hessels, J. Sluman, Gianni Bernardi, Jörg R. Hörandel, I. M. Avruch, James M. Anderson, F. de Gasperin, Frank Breitling, Roberto Pizzo, H. J. A. Röttgering, Satyendra Thoudam, G. Kuper, Olaf Wucknitz, M. Serylak, H. Munk, Wilfred Frieswijk, Ashish Asgekar, Marcus Brüggen, M. Iacobelli, Y. Tang, W. Reich, S. ter Veen, A. W. Gunst, Anna M. M. Scaife, Laura Rossetto, Ralph A. M. J. Wijers, A. G. Polatidis, Rebecca McFadden, Arthur Corstanje, Annalisa Bonafede, Christian Vocks, G. M. Loose, Sera Markoff, Jean-Mathias Grießmeier, Michel Tagger, D. Carbone, R. C. Vermeulen, T. Huege, Olaf Scholten, Oleg Smirnov, Huib Intema, Cyril Tasse, J. W. Broderick, E. de Geus, R. J. Dettmar, George Heald, W. N. Brouw, Gottfried Mann, High Energy Astrophys. & Astropart. Phys (API, FNWI), Radboud University [Nijmegen], Netherlands Institute for Radio Astronomy (ASTRON), Karlsruhe Institute of Technology (KIT), University of Groningen [Groningen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Laboratoire Analyse, Géométrie et Applications (LAGA), Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris 13 (UP13)-Institut Galilée-Centre National de la Recherche Scientifique (CNRS), Institute for Mathematics Applied to Geoscience, National Center for Atmospheric Research [Boulder] (NCAR), SRON Netherlands Institute for Space Research (SRON), Australia Telescope National Facility (ATNF), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), University of Edinburgh, Jacobs University [Bremen], Leibniz-Institut für Astrophysik Potsdam (AIP), University of Southampton, Kapteyn Astronomical Institute [Groningen], University of Amsterdam [Amsterdam] (UvA), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Onsala Space Observatory, Dept. of Radio and Space Science, Chalmers University of Technology, Chalmers University of Technology [Göteborg], Hamburger Sternwarte/Hamburg Observatory, Universität Hamburg (UHH), Medstar Research Institute, Astronomisches Institut der Ruhr-Universität Bochum, Ruhr-Universität Bochum [Bochum], Thüringer Landessternwarte Tautenburg (TLS), SETI Institute, Institute of Mathematical and Physical Sciences, Département de Géologie, Université de Montréal (UdeM), Leiden Observatory [Leiden], Universiteit Leiden, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Max-Planck-Institut für Radioastronomie (MPIFR), Oxford Astrophysics, University of Oxford, Columbia Astrophysics Laboratory (CAL), Columbia University [New York], Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Oulu, Center for Information Technology CIT, Université de Groningen, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Radio Astronomy Observatory [Charlottesville] (NRAO), National Radio Astronomy Observatory (NRAO), School of Physics and Astronomy [Southampton], Interactions Son Musique Mouvement, Sciences et Technologies de la Musique et du Son (STMS), Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Grahamstown, Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures (DSMZ), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Université Paris-Sud - Paris 11 (UP11), SKA South Africa, Ska South Africa, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Finca El Encin, Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario (IMIDRA), Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Observatoire de Paris - Site de Paris (OP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, European Project: 227610,EC:FP7:ERC,ERC-2008-AdG,LOFAR-AUGER(2009), European Project: 640130,H2020,ERC-2014-STG,LOFAR(2015), Radboud university [Nijmegen], Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology, nstitute for Nuclear Physics (IKP), Karlsruhe Institute of Technology, Université Paris 8 Vincennes-Saint-Denis (UP8)-Centre National de la Recherche Scientifique (CNRS)-Institut Galilée-Université Paris 13 (UP13), Universiteit Leiden [Leiden], Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), University of Oxford [Oxford], École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Research unit Astroparticle Physics, Astronomy, and Kapteyn Astronomical Institute
Subjects: TELESCOPE, High-energy astronomy, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Cosmic ray, Astrophysics, Electron, Astrophysics::Cosmology and Extragalactic Astrophysics, Radiation, EXTENSIVE AIR-SHOWERS, 01 natural sciences, 0103 physical sciences, 010303 astronomy & astrophysics, Astroparticle physics, Physics, Multidisciplinary, COSMIC cancer database, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, LOFAR, ENERGY-SPECTRUM, SIMULATIONS, PULSES, High-energy astrophysics, Air shower, 13. Climate action, [SDU]Sciences of the Universe [physics], ARRAY, Neutrino, Particle astrophysics, EMISSION
Abstract: Cosmic rays are the highest-energy particles found in nature. Measurements of the mass composition of cosmic rays with energies of 1017–1018 electronvolts are essential to understanding whether they have galactic or extragalactic sources. It has also been proposed that the astrophysical neutrino signal1 comes from accelerators capable of producing cosmic rays of these energies2. Cosmic rays initiate air showers—cascades of secondary particles in the atmosphere—and their masses can be inferred from measurements of the atmospheric depth of the shower maximum3 (Xmax; the depth of the air shower when it contains the most particles) or of the composition of shower particles reaching the ground4. Current measurements5 have either high uncertainty, or a low duty cycle and a high energy threshold. Radio detection of cosmic rays6,7,8 is a rapidly developing technique9 for determining Xmax (refs 10, 11) with a duty cycle of, in principle, nearly 100 per cent. The radiation is generated by the separation of relativistic electrons and positrons in the geomagnetic field and a negative charge excess in the shower front6,12. Here we report radio measurements of Xmax with a mean uncertainty of 16 grams per square centimetre for air showers initiated by cosmic rays with energies of 1017–1017.5 electronvolts. This high resolution in Xmax enables us to determine the mass spectrum of the cosmic rays: we find a mixed composition, with a light-mass fraction (protons and helium nuclei) of about 80 per cent. Unless, contrary to current expectations, the extragalactic component of cosmic rays contributes substantially to the total flux below 1017.5 electronvolts, our measurements indicate the existence of an additional galactic component, to account for the light composition that we measured in the 1017–1017.5 electronvolt range.
Published: 2019
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27. Adaptive and compliant wingtip devices enabled by additive manufacturing and multistable structures

Author: Kimberly Gustafson, Aimy Wissa, Gregory W. Reich, Alexander M. Pankonien, and Luis Urrutia
Subjects: Coupling, Lift (force), Materials science, Bistability, Truss, Mechanical engineering, Aerodynamics, Bending, Degrees of freedom (mechanics), Wind tunnel
Abstract: Multifunctional lifting surfaces can expand the mission capabilities of aerial vehicles with a minimal number of components added to the vehicle. This paper presents a bio-inspired segmented wingtip concept for lift enhancement enabled by passive structural tailoring and active bistable truss mechanisms. The development of wingtips stems from studies of birds with desirable flight capabilities. The structural characteristics and maneuverable changes of a bird’s primary feathers during flight have identified three notable feather degrees of freedom: incidence angle, dihedral angle, and gap spacing. Wind tunnel experiments conducted on multi-wingtip systems have determined that different wingtip orientations and spacings are desired to enhance aerodynamic performance depending on the flight conditions. These results suggest that the wingtip degrees of freedom must be varied during flight to achieve optimal aerodynamic performance. This paper presents two structural concepts, one passive and one active, to achieve desired morphological wingtip parameters during flight. The passive structural concept exploits bend-twist coupling of additively manufactured composite laminate wingtips by using aerodynamic loads to induce passive shape adaptation of the composite wingtips to control the twist and dihedral angles. The active concept utilizes bistable truss mechanisms to vary the wingtip gap spacing. The force-displacement responses of bistable mechanisms and the bending and twist of bend-twist coupled composite wingtips are measured using a universal testing machine and Digital Image Correlation, respectively. Experimental results include the energy storage characterization of the bistable mechanisms as a function of material characteristics and the bend-twist coupling of the composite wingtips as a function of fabrication process and laminate properties.
Published: 2019
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28. L-System-Generated Mechanism Topology Optimization Using Graph-Based Interpretation

Author: Ergun Akleman, Brent R. Bielefeldt, Gregory W. Reich, Philip S. Beran, and Darren J. Hartl
Subjects: 020301 aerospace & aeronautics, Computer science, Mechanical Engineering, Graph based, Topology optimization, Topology (electrical circuits), 02 engineering and technology, Space (mathematics), Topology, Interpretation (model theory), Mechanism (engineering), 020303 mechanical engineering & transports, 0203 mechanical engineering, L-system
Abstract: Traditional topology optimization techniques, such as density-based and level set methods, have proven successful in identifying potential design configurations for structures and mechanisms but suffer from rapidly increasing design space dimensionality and the possibility of converging to local minima. A heuristic alternative to these approaches couples a genetic algorithm with a Lindenmayer system (L-system), which encodes design variables and governs the development of the structure when coupled with an interpreter to translate genomic information into structural topologies. This work discusses the development of a graph-based interpretation scheme referred to as spatial interpretation for the development of reconfigurable structures (SPIDRS). This framework allows for the effective exploration of mechanism design spaces using a limited number of design variables. The theory and implementation of this method are detailed, and multiple case studies are presented to demonstrate the ability of SPIDRS to generate adaptive structures capable of achieving multiple design goals.
Published: 2019
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29. Aeroelastic Topology Optimization of a Morphing Airfoil in Supersonic Flow using Evolutionary Design

Author: Adam P. Christopherson, Gregory W. Reich, Joshua D. Hodson, Joshua D. Deaton, Philip S. Beran, and Alexander M. Pankonien
Subjects: Airfoil, Morphing, Computer science, business.industry, Topology optimization, Aerospace engineering, Aeroelasticity, business, Choked flow
Published: 2019
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30. Conceptual Multidisciplinary Design and Optimization of Morphing Aircraft

Author: Trenton White, Daniel L. Clark, Jason Y. Kao, Scott Burton, and Gregory W. Reich
Subjects: Morphing, Computer science, Multidisciplinary approach, Systems engineering
Published: 2019
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31. A Sino-German 6cm polarisation survey of the Galactic plane IX. HII regions

Author: L. G. Hou, Jin-Lin Han, Patricia Reich, X. Y. Gao, and W. Reich
Subjects: Physics, 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Galactic plane, 01 natural sciences, Methods observational, Astrophysics - Astrophysics of Galaxies, language.human_language, German, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, language, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Large-scale radio continuum surveys provide data to get insights into the physical properties of radio sources. HII regions are prominent radio sources produced by thermal emission of ionised gas around young massive stars. We identify and analyse HII regions in the Sino-German 6cm polarisation survey of the Galactic plane. Objects with flat radio continuum spectra together with infrared and/or Halpha emission were identified as HII regions. For HII regions with small apparent sizes, we cross-matched the 6cm small-diameter source catalogue with the radio HII region catalogue compiled by Paladini and the infrared HII region catalogue based on the WISE data. Extended HII regions were identified by eye by overlaying the Paladini and the WISE HII regions onto the 6cm survey images for coincidences. The TT-plot method was employed for spectral index verification. A total of 401 HII regions were identified and their flux densities were determined with the Sino-German 6cm survey data. In the surveyed area, 76 pairs of sources are found to be duplicated in the Paladini HII region catalogue, mainly due to the non-distinction of previous observations with different angular resolutions, and 78 objects in their catalogue are misclassified as HII regions, being actually planetary nebulae, supernova remnants or extragalactic sources that have steep spectra. More than 30 HII regions and HII region candidates from our 6cm survey data, especially extended ones, do not have counterparts in the WISE HII region catalogue, of which 9 are identified for the first time. Based on the newly derived radio continuum spectra and the evidence of infrared emission, the previously identified SNRs G11.1-1.0, G20.4+0.1 and G16.4-0.5 are believed to be HII regions., version after some minor corrections and language editing, full Table 2 - 5 will appear in CDS, accepted for publication in A&A
Published: 2019

32. Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3D Galactic halo magnetic field

Author: V. I. Kondratiev, Anna V. Bilous, George Heald, Benjamin Stappers, C. L. Van Eck, Daniele Michilli, W. Reich, A. Noutsos, M. Iacobelli, Michael Kramer, Charlotte Sobey, E. J. Polzin, M. I. R. Alves, Torsten A. Enßlin, Aris Karastergiou, Patrick Weltevrede, Maura Pilia, Jason W. T. Hessels, J. van Leeuwen, C. M. Tan, J.-M. Grießmeier, Marijke Haverkorn, Ettore Carretti, Joris P. W. Verbiest, Evan Keane, Max-Planck-Institut für Radioastronomie (MPIFR), Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 617199,EC:FP7:ERC,ERC-2013-CoG,ALERT(2014), Radboud University [Nijmegen], Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: Astronomy, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, general [pulsars], 01 natural sciences, law.invention, Galactic halo, Radio telescope, symbols.namesake, Pulsar, law, pulsars: general, polarimetric [techniques], 0103 physical sciences, Faraday effect, Faraday cage, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Galaxy: structure, Astrophysics::Galaxy Astrophysics, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, magnetic fields [ISM], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Scale height, LOFAR, Galactic plane, Astrophysics - Astrophysics of Galaxies, techniques: polarimetric, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), symbols, ISM: magnetic fields, radio telescopes, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], structure [Galaxy]
Abstract: We determined Faraday rotation measures (RMs) towards 137 pulsars in the northern sky, using Low-Frequency Array (LOFAR) observations at 110-190 MHz. This low-frequency RM catalogue, the largest to date, improves the precision of existing RM measurements on average by a factor of 20 - due to the low frequency and wide bandwidth of the data, aided by the RM synthesis method. We report RMs towards 25 pulsars for the first time. The RMs were corrected for ionospheric Faraday rotation to increase the accuracy of our catalogue to approximately 0.1 rad m$^{\rm -2}$. The ionospheric RM correction is currently the largest contributor to the measurement uncertainty. In addition, we find that the Faraday dispersion functions towards pulsars are extremely Faraday thin - mostly less than 0.001 rad m$^{\rm -2}$. We use these new precise RM measurements (in combination with existing RMs, dispersion measures, and distance estimates) to estimate the scale height of the Galactic halo magnetic field: 2.0$\pm$0.3 kpc for Galactic quadrants I and II above and below the Galactic plane (we also evaluate the scale height for these regions individually). Overall, our initial low-frequency catalogue provides valuable information about the 3-D structure of the Galactic magnetic field., 31 pages, including 13 figures, 6 tables. Accepted for publication in MNRAS
Published: 2019
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33. Needle-like structures discovered on positively charged lightning branches

Author: S. ter Veen, A. W. Gunst, M. A. Garrett, Laura Rossetto, A. J. van der Horst, J.-M. Grießmeier, R. Blaauw, Mark J. Bentum, R. J. van Weeren, Jörg P. Rachen, B. Ciardi, Pietro Zucca, Heino Falcke, R. Pekal, Aleksandar Shulevski, Anna Nelles, P. Maat, M. J. Norden, H. Paas, James M. Anderson, Stijn Buitink, Katie Mulrey, Richard Fallows, M. C. Toribio, J. Sluman, Luitje Koopmans, Olaf Scholten, Oleg Smirnov, Jörg R. Hörandel, Jochen Eislöffel, Roberto Pizzo, Hanna Rothkaehl, H. J. A. Röttgering, Harvey Butcher, P. Zarka, Olaf Wucknitz, Antonia Rowlinson, T. N. G. Trinh, Andrzej Krankowski, S. Duscha, Arthur Corstanje, Tim Huege, I. M. Avruch, Vishambhar Pandey, Ralph A. M. J. Wijers, M. Iacobelli, Pragati Mitra, Jason W. T. Hessels, Matthias Hoeft, A. van Ardenne, Tobias Winchen, Antonio Bonardi, Dominik J. Schwarz, W. N. Brouw, Brian Hare, Michel Tagger, W. Reich, J. W. Broderick, E. de Geus, Pim Schellart, Marcus Brüggen, M. P. van Haarlem, M. Pandey-Pommier, Joseph R. Dwyer, Marian Soida, High Energy Astrophys. & Astropart. Phys (API, FNWI), KVI Center for Advanced Radiation Technology, University of Groningen [Groningen], Radboud university [Nijmegen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Netherlands Institute for Radio Astronomy (ASTRON), Astrophysical Institute, Vrije Universiteit Brussel, Vrije Universiteit [Brussels] (VUB), Karlsruher Institut für Technologie (KIT), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), SRON Netherlands Institute for Space Research (SRON), University of Southampton, Kapteyn Astronomical Institute [Groningen], Jacobs University [Bremen], Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Medstar Research Institute, Thüringer Landessternwarte Tautenburg (TLS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Institute of Geodesy, Center for Information Technology CIT, Université de Groningen, Centre de Recherche Astrophysique de Lyon (CRAL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Department of Applied Chemistry (DAC), Banaras Hindu University [Varanasi] (BHU), Max-Planck-Institut für Radioastronomie (MPIFR), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk (PAN), Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), European Project: 227610,EC:FP7:ERC,ERC-2008-AdG,LOFAR-AUGER(2009), European Project: 640130,H2020,ERC-2014-STG,LOFAR(2015), Center for Wireless Technology Eindhoven, Electromagnetics, EM for Radio Science Lab, Physics, Elementary Particle Physics, Astronomy and Astrophysics Research Group, Department of Bio-engineering Sciences, Faculty of Sciences and Bioengineering Sciences, Radboud University [Nijmegen], Vrije Universiteit Brussel (VUB), Global Aerospace, Adran Ffiseg, Prifysgol Cymru Aberystwyth, Universiteit Leiden, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Department of Physics the George Washington University, Space Radio-Diagnostic Research Center [Olsztyn], University of Warmia and Mazury [Olsztyn], Polska Akademia Nauk = Polish Academy of Sciences (PAN), Interactions Son Musique Mouvement, Sciences et Technologies de la Musique et du Son (STMS), Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Rhodes University, Grahamstown, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-IRCAM-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomy, and Research unit Astroparticle Physics
Subjects: [PHYS]Physics [physics], Physics, Multidisciplinary, 010504 meteorology & atmospheric sciences, Astronomy, 010502 geochemistry & geophysics, 01 natural sciences, Lightning, [SDU]Sciences of the Universe [physics], Natural phenomenon, ddc:530, Spatiotemporal resolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Initiation point, 0105 earth and related environmental sciences
Abstract: Nature / Physical science 568(7752), 360 - 363 (2019). doi:10.1038/s41586-019-1086-6, Lightning is a dangerous yet poorly understood natural phenomenon. Lightning forms a network of plasma channels propagating away from the initiation point with both positively and negatively charged ends—called positive and negative leaders. Negative leaders propagate in discrete steps, emitting copious radio pulses in the 30–300-megahertz frequency band that can be remotely sensed and imaged with high spatial and temporal resolution. Positive leaders propagate more continuously and thus emit very little high-frequency radiation. Radio emission from positive leaders has nevertheless been mapped, and exhibits a pattern that is different from that of negative leaders. Furthermore, it has been inferred that positive leaders can become transiently disconnected from negative leaders, which may lead to current pulses that both reconnect positive leaders to negative leaders and cause multiple cloud-to-ground lightning events. The disconnection process is thought to be due to negative differential resistance, but this does not explain why the disconnections form primarily on positive leaders, or why the current in cloud-to-ground lightning never goes to zero. Indeed, it is still not understood how positive leaders emit radio-frequency radiation or why they behave differently from negative leaders. Here we report three-dimensional radio interferometric observations of lightning over the Netherlands with unprecedented spatiotemporal resolution. We find small plasma structures—which we call ‘needles’—that are the dominant source of radio emission from the positive leaders. These structures appear to drain charge from the leader, and are probably the reason why positive leaders disconnect from negative ones, and why cloud-to-ground lightning connects to the ground multiple times., Published by Macmillan28177, London
Published: 2019
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34. Active Control of Origami Inspired Camber Morphing Airfoil for Gust Load Alleviation

Author: Kaman Thapa Magar, Kazuko Fuchi, Alexander M. Pankonien, Richard V. Beblo, and Gregory W. Reich
Subjects: Airfoil, Vibration, Morphing, business.industry, Computer science, Camber (aerodynamics), Control system, Structural engineering, business, Active control
Abstract: An origami design pattern is integrated to an active control system through camber morphing for vibration suppression and gust load alleviation in a typical wing section. Origami design parameters are optimized to have high sensitivity in chordwise fold angle and a maximum camber of 10% chord. A LQR controller is used to achieve the desired vibration suppression in a lightly damped aeroelastic system. The desired vibration suppression is achieved with change in camber of below 5% chord for an initial displacement condition induced vibration and less than 1% chord for gust excited vibration. Results also show that camber morphing is effective in suppressing vibration in both pitch and plunge degrees of freedom simultaneously.
Published: 2018
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35. Structural Sizing of Aircraft Wings and Fuselages in Conceptual Multidisciplinary Design Processes

Author: Gregory W. Reich, Trenton White, Jason Y. Kao, Matthew S. Leonard, and Scott Burton
Subjects: 020301 aerospace & aeronautics, 0203 mechanical engineering, Fuselage, Multidisciplinary approach, Computer science, 0211 other engineering and technologies, Systems engineering, 02 engineering and technology, Sizing, 021106 design practice & management
Published: 2018
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36. Multi-Material Printed Trailing Edge Control Surface for an Aeroservoelastic Wind Tunnel Model

Author: Alexander M. Pankonien, Nitin D. Bhagat, Gregory W. Reich, and Ryan J. Durscher
Subjects: Surface (mathematics), 020301 aerospace & aeronautics, 0203 mechanical engineering, Computer science, Acoustics, 0103 physical sciences, Multi material, Trailing edge, 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, Wind tunnel
Published: 2018
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37. Low-frequency radio absorption in Cassiopeia A

Author: M. Arias, J. Vink, F. de Gasperin, P. Salas, J. B. R. Oonk, R. J. van Weeren, A. S. van Amesfoort, J. Anderson, R. Beck, M. E. Bell, M. J. Bentum, P. Best, R. Blaauw, F. Breitling, J. W. Broderick, W. N. Brouw, M. Brüggen, H. R. Butcher, B. Ciardi, E. de Geus, A. Deller, P. C. G. van Dijk, S. Duscha, J. Eislöffel, M. A. Garrett, J. M. Grießmeier, A. W. Gunst, M. P. van Haarlem, G. Heald, J. Hessels, J. Hörandel, H. A. Holties, A. J. van der Horst, M. Iacobelli, E. Juette, A. Krankowski, J. van Leeuwen, G. Mann, D. McKay-Bukowski, J. P. McKean, H. Mulder, A. Nelles, E. Orru, H. Paas, M. Pandey-Pommier, V. N. Pandey, R. Pekal, R. Pizzo, A. G. Polatidis, W. Reich, H. J. A. Röttgering, H. Rothkaehl, D. J. Schwarz, O. Smirnov, M. Soida, M. Steinmetz, M. Tagger, S. Thoudam, M. C. Toribio, C. Vocks, M. H. D. van der Wiel, R. A. M. J. Wijers, O. Wucknitz, P. Zarka, P. Zucca, API (FNWI), High Energy Astrophys. & Astropart. Phys (API, FNWI), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), LOFAR, Astronomy, Astronomical Institute Anton Pannekoek, University of Amsterdam, SRON Netherlands Institute for Space Research (SRON), Leiden Observatory, Netherlands Institute for Radio Astronomy (ASTRON), GeoForschungsZentrum (GFZ), Max-Planck-Institut für Astronomie (MPIA), University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia, University of Edinburgh, Leibniz-Institut für Astrophysik Potsdam (IAP), University of Hamburg, Gojenbergsweg 112, 21029, Hamburg, Germany, Mount Stromlo Observatory, Australian National University, Max-Planck-Institut für Astrophysik (MPA), Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Thüringer Landessternwarte, Tautenburg Observatory, JBCA School of Physics and Astronomy, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), CSIRO Astronomy and Space Science, Department of Astrophysics, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands, George Washington University, Astronomisches Institut der Ruhr-Universitat Bochum, Universitaetsstrasse 150, 44780, Bochum, Germany, University of Warmia and Mazury [Olsztyn], Department of Physics and Technology, University of Tromso, Tromso, Norway, Department of Physics and Astronomy, University of Missouri, Center for Information Technology, University of Groningen (CIT), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Poznan University of Technology, Space Research Center, Polish Academy of Sciences (Torun), Universität Bielefeld = Bielefeld University, Department of Physics and Electronics, Rhodes University, Astronomical Observatory, Jagiellonian University, Department of Physics and Electrical Engineering, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Electromagnetics, Center for Wireless Technology Eindhoven, EM for Radio Science Lab, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherche Astrophysique de Lyon ( CRAL ), École normale supérieure - Lyon ( ENS Lyon ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), and Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: TI-44, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astronomy, radio continuum: general, Astrophysics, 7. Clean energy, 01 natural sciences, supernova remnants / radiation mechanisms: general / radio continuum, Astrophysics::Solar and Stellar Astrophysics, individual, Ejecta, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, SUPERNOVA REMNANT CASSIOPEIA, general [radiation mechanisms], ISM: supernova remnants, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, ABSOLUTE SPECTRUM, supernova remnants [ISM], Radius, Supernova, EJECTA, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, general [radio continuum], Astrophysics - High Energy Astrophysical Phenomena, Cas A / ISM, individual: Cas A [supernovae], supernovae, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, radiation mechanisms: general, LARGE ARRAY, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, Astronomy & Astrophysics, ACCELERATION, Radio spectrum, VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430::Astrofysikk, astronomi: 438, 0103 physical sciences, 3-DIMENSIONAL STRUCTURE, Astrophysics::Galaxy Astrophysics, EXPLOSION, 010308 nuclear & particles physics, Astronomy and Astrophysics, LOFAR, Cassiopeia A, VDP::Mathematics and natural science: 400::Physics: 430::Astrophysics, astronomy: 438, supernovae: individual: Cas A, 13. Climate action, Space and Planetary Science, general, EMISSION, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], CAS-A
Abstract: Cassiopeia A is one of the best-studied supernova remnants. Its shocked ejecta emits brightly in radio and X-rays. Its unshocked ejecta can be studied through infrared emission, the radio-active decay of $^{44}$Ti, and low frequency free-free absorption due to cold gas internal to the shell. Free-free absorption is affected by the mass, geometry, temperature, and ionisation conditions in the absorbing gas. Observations at the lowest radio frequencies constrain a combination of these properties. We use LOFAR LBA observations at 30-77 MHz and L-band VLA observations to compare $u-v$-matched images with a common resolution of 17". We simultaneously fit, per pixel, for the emission measure and the ratio of the emission from the unabsorbed front of the shell versus the absorbed back of the shell. We explore the effects that low temperatures and a high degree of clumping can have on the derived physical properties, such as mass and density. We also compile published radio flux measurements, fit for the absorption processes that occur in the radio band, and consider how they affect the secular decline of the source. We find a mass in the unshocked ejecta of $M = 2.95 \pm {0.48} \,M_{\odot}$ for an assumed gas temperature of $T=100$ K. This estimate is reduced for colder gas temperatures and if the ejecta are clumped. We measure the reverse shock to have a radius of $114$" $\pm $6". We also find that a decrease in the amount of mass in the unshocked ejecta (as more and more material meets the reverse shock and heats up) cannot account for the observed low frequency behaviour of the secular decline rate. To reconcile our low frequency absorption measurements with models that predict little mass in the unshocked ejecta we need the ejecta to be very clumped, or the temperature in the cold gas to be low ($\sim10$ K). Both conditions can jointly contribute to the high absorption., Accepted for publication in A&A v2: including the DOI, language edits
Published: 2018
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38. Aligning nickel particles for joule heating in epoxy shape memory polymer using a magnetic field and linear vibration

Author: Gregory W. Reich, James J. Joo, and Richard V. Beblo
Subjects: Materials science, Mechanical Engineering, chemistry.chemical_element, 02 engineering and technology, Epoxy, 021001 nanoscience & nanotechnology, Linear vibration, Magnetic field, Nickel, Shape-memory polymer, 020303 mechanical engineering & transports, 0203 mechanical engineering, chemistry, visual_art, visual_art.visual_art_medium, General Materials Science, Composite material, 0210 nano-technology, Joule heating
Abstract: One of the major remaining barriers to the widespread adoption of thermally activated shape memory polymer is the method used to heat them. Presented is an investigation into using 5 μm nickel particles aligned into chains as embedded joule heaters for epoxy shape memory polymer. The high density of particle chain heaters reduces the time and energy required to reach transition by minimizing excess heat required due to the low thermal conductivity of the polymer by heating the material more uniformly. The chains are formed by curing the polymer in a uniform magnetic field generated by two sets of N42SH neodymium magnets above and below the sample approximately 57 mm apart. Modeling of the induced magnetic field within and between particles during curing and an analytical model predicting particle mobility in a fluid with respect to vibration frequency and amplitude are presented and discussed in context to this work. Since epoxy resin has a high viscosity, particle mobility is encouraged by sonicating the sample at 300 Hz at an amplitude of approximately 50 μm prior to polymerization using an industrial shaker and Teflon guides. Copper mesh electrodes are attached to the resulting samples using 10% by volume nickel particle shape memory polymer epoxy. Significant particle alignment is confirmed via optical microscope images. Electrical resistivity is measured as low as 57 Ω mm at nickel volume concentrations of 1.0%. Infrared images of the samples during heating are presented, and electrical energy required with respect to sample thermal capacity is estimated.
Published: 2015
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39. Hard pine stem rusts on lodgepole pine at a site-preparation study in sub-boreal British Columbia: effects over 24 years

Author: Richard W. Reich, Jacob O. Boateng, Torsten Kaffanke, Lorne Bedford, Jean L. Heineman, and Amanda F. Linnell Nemec
Subjects: Pinus contorta, Global and Planetary Change, Veterinary medicine, Ecology, biology, food and beverages, Forestry, Endocronartium harknessii, biology.organism_classification, medicine.disease, Rust, Comandra, Boreal, Untreated control, Botany, medicine, Gall, Volume loss
Abstract: Site preparation can improve lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson) survival and growth; however, we lack information regarding possible interactions between treatment effects and the impacts of western gall rust (Endocronartium harknessii (J.P. Moore) Y. Hirats.) and comandra blister rust (Cronartium comandrae Peck). Mechanical and burning techniques examined over 24 years at a sub-boreal British Columbia site did not significantly increase rust infection rates or characteristics relative to an untreated control. Most infection occurred before age 10 years and at heights
Published: 2015
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40. 101 Things That Piss Me Off : And Thousands of Other Things That Suck Just As Much

Author: Herb W. Reich and Herb W. Reich
Abstract: Complaining, psychologists assert, is good for your health. It acts as a relief valve to help dispel the pent up energy generated by our daily frustrations, personal peeves, and life-long vexations. Now curmudgeons, gripers, grousers, and complainers have their own place to discard their tension! 101 Things That Piss Me Off is the manifesto guaranteed to help even the crabbiest soul let loose. Here is just a sample list of items guaranteed to piss anyone off:•Aggressive drivers who give the finger•People who graduated from assertiveness courses•Elevator music•Having the best senators money can buy•Appliances that fail the day after the warranty expires•Nineteen-year-old tech millionaires•People who are more inept than we give them credit for
Published: 2017

41. Two Different Models for How Voters Can Choose Among Candidates’ Election Proposals

Author: John Hall and John W. Reich
Subjects: Political science, Public administration, Blanket primary
Published: 2016
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42. The effects of surface topography control using liquid crystal elastomers on bodies in flow

Author: Timothy J. White, Michael Settle, Tyler Guin, Richard V. Beblo, and Gregory W. Reich
Subjects: Lift (force), Digital image correlation, Flow control (fluid), Particle image velocimetry, Drag, law, Conical surface, Composite material, Wind tunnel, Cylinder (engine), law.invention
Abstract: Surface topography control has use across many applications including delayed separation of flow via selective boundary-layer tripping. Recently, advances with liquid crystal elastomers (LCE) have been leveraged for controlled, repeatable, out-of-plane deformations that could enable these topographical changes. An aligned LCE deforms when heated, associated with a loss in order. Circumferential patterns fabricated through the thickness of the LCE film yield a predictable conical out-of-plane deformation that can control surface topography. This study focuses on the experimental investigation of LCE behavior for flow control. Initially, the deformations of LCE samples 1/2” in diameter and 50 µm thick were characterized using Digital Image Correlation under uniform positive and negative gauge pressures at various temperatures. Surface topography showed strong dependence on boundary conditions, sample dimensions, and pattern location relative to the applied boundary conditions, informing adjustment of the LCE of the chemistry to produce higher modulus and glassy materials. As an initial demonstration of the ability to control flow, Then, to demonstrate the potential for flow control, 3D printed cylinders with varying arrangements of representative topographical features were characterized in a wind tunnel with Particle Image Velocimetry. Results showed that features with a maximum deflection height of 1.5 mm in a two-row arrangement can form an asymmetric wake about a 73 mm diameter cylinder that reduces drag while generating lift. These results inform subsequent investigation of active LCE elements on a cylinder that are currently under examination.
Published: 2018
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43. LOFAR in Germany

Author: W. Reich
Subjects: Engineering, business.industry, Astronomy, General Medicine, Astrophysics, Digital radio, LOFAR, law.invention, Telescope, Radio telescope, Long wavelength, law, lcsh:TA1-2040, business, lcsh:Engineering (General). Civil engineering (General)
Abstract: The LOw Frequency ARray – LOFAR – is a new fully digital radio telescope designed for frequencies between 30 MHz and 240 MHz centered in the Netherlands. In May 2006 ten German institutes formed the German LOng Wavelength consortium – GLOW – to coordinate its contributions and scientific interests to the LOFAR project. The first LOFAR station CS1 was installed in summer 2006 near Exloo/Netherlands. The second station IS-G1 is presently been placed in the immediate vicinity of the Effelsberg 100-m radio telescope near Bad Münstereifel/Germany. This contribution briefly describes the basic properties and aims of LOFAR, the aims of the GLOW consortium and the actual activities to install a LOFAR station at the Effelsberg site.
Published: 2018

44. Optimal Control Framework for Gust Load Alleviation using Real time Aerodynamic Force Prediction from Artificial Hair Sensor Array

Author: Alexander M. Pankonien, Gregory W. Reich, Kaman Thapa Magar, and Richard V. Beblo
Subjects: Aerodynamic force, 020301 aerospace & aeronautics, 0203 mechanical engineering, Sensor array, Control theory, Computer science, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, Optimal control
Published: 2018
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45. A radio continuum and polarization study of SNR G57.2+0.8 associated with magnetar SGR 1935+2154

Author: Bryan Gaensler, Roland Kothes, X. H. Sun, and W. Reich
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Magnetar, Polarization (waves), 01 natural sciences, ISM: individual objects (G57.2+0.8, SGR1935+2154), stars: magnetars, Space and Planetary Science, 0103 physical sciences, ISM: magnetic fields, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants
Abstract: We present a radio continuum and linear polarization study of the Galactic supernova remnant G57.2+0.8, which may host the recently discovered magnetar SGR1935+2154. The radio SNR shows the typical radio continuum spectrum of a mature supernova remnant with a spectral index of $\alpha = -0.55 \pm 0.02$ and moderate polarized intensity. Magnetic field vectors indicate a tangential magnetic field, expected for an evolved SNR, in one part of the SNR and a radial magnetic field in the other. The latter can be explained by an overlapping arc-like feature, perhaps a pulsar wind nebula, emanating from the magnetar. The presence of a pulsar wind nebula is supported by the low average braking index of 1.2, we extrapolated for the magnetar, and the detection of diffuse X-ray emission around it. We found a distance of 12.5 kpc for the SNR, which identifies G57.2+0.8 as a resident of the Outer spiral arm of the Milky Way. The SNR has a radius of about 20 pc and could be as old as 41,000 years. The SNR has already entered the radiative or pressure-driven snowplow phase of its evolution. We compared independently determined characteristics like age and distance for both, the SNR and SGR1935+2154, and conclude that they are physically related., Comment: accepted by The Astrophysical Journal, 16 pages, 10 figures
Published: 2018

46. The association of a J-burst with a solar jet

Author: Helmut O. Rucker, Rebecca McFadden, B. Ciardi, J. M. Anderson, H. Munk, J. W. Broderick, O. Wucknitz, H. Paas, E. Juette, W. Reich, Heino Falcke, Matthias Hoeft, Hamish A. S. Reid, Oleg Smirnov, L. Cerrigone, A. G. Polatidis, Philip Best, Emanuela Orrú, Matthias Steinmetz, J. Magdalenic, D. D. Mulcahy, Gottfried Mann, C. Vocks, P. Zarka, V. N. Pandey, Ashish Asgekar, Mark J. Bentum, Gerard H. Kuper, A. Nelles, Annalisa Bonafede, M. Iacobelli, Diana E. Morosan, Dominik J. Schwarz, M. Pandey-Pommier, M. C. Toribio, R. C. Vermeulen, Jochen Eislöffel, Jean-Mathias Griessmeier, M. Tagger, S. ter Veen, A. W. Gunst, S. Duscha, Mario M. Bisi, R. Blaauw, R. J. van Weeren, D. McKay-Bukowski, I. M. Avruch, Peter T. Gallagher, John McKean, Martin Bell, E. de Geus, M. A. Garrett, Richard Fallows, Frank Breitling, Bo Thidé, J. Sluman, Roberto Pizzo, Marcus Brüggen, Satyendra Thoudam, Astronomy, Kapteyn Astronomical Institute, Trinity College Dublin, Netherlands Institute for Radio Astronomy (ASTRON), SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, Leibniz-Institut für Astrophysik Potsdam (AIP), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Royal Observatory of Belgium [Brussels] (ROB), Austrian Academy of Sciences (OeAW), Swedish Institute of Space Physics [Uppsala] (IRF), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Royal Observatory Edinburgh (ROE), University of Edinburgh, Jacobs University [Bremen], Universität Hamburg (UHH), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Thüringer Landessternwarte Tautenburg (TLS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden, Ruhr-Universität Bochum [Bochum], University of Oulu, Radboud University [Nijmegen], Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Universität Bielefeld, Rhodes University, Grahamstown, Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH / Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures (DSMZ), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Universiteit Leiden [Leiden], Radboud university [Nijmegen], École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Harvard University [Cambridge]-Smithsonian Institution
Subjects: corona [Sun], 010504 meteorology & atmospheric sciences, Astronomy, particle emission [Sun], Astrophysics, 01 natural sciences, ELECTRON-BEAMS, CORONA, Sun: magnetic, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), 010303 astronomy & astrophysics, Sun: magnetic fields, fields, Physics, Jet (fluid), Solar flare, Sun: radio radiation, Astrophysics::Instrumentation and Methods for Astrophysics, FLARE, Astrophysics - Solar and Stellar Astrophysics, magnetic fields [Sun], Physical Sciences, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, FLUX, DYNAMICS-OBSERVATORY SDO, Field line, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy & Astrophysics, ACCELERATION, Computer Science::Digital Libraries, III BURSTS, Sun: particle emission, 0103 physical sciences, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Science & Technology, radio radiation [Sun], [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Sun: corona, Northern Hemisphere, Astronomy and Astrophysics, Magnetic reconnection, LOFAR, Physics::History of Physics, X-RAY JETS, 13. Climate action, Space and Planetary Science, Extreme ultraviolet, RADIO-EMISSION
Abstract: Context. The Sun is an active star that produces large-scale energetic events such as solar flares and coronal mass ejections and numerous smaller-scale events such as solar jets. These events are often associated with accelerated particles that can cause emission at radio wavelengths. The reconfiguration of the solar magnetic field in the corona is believed to be the cause of the majority of solar energetic events and accelerated particles. Aims. Here, we investigate a bright J-burst that was associated with a solar jet and the possible emission mechanism causing these two phenomena. Methods. We used data from the Solar Dynamics Observatory (SDO) to observe a solar jet, and radio data from the Low Frequency Array (LOFAR) and the Nan\c{c}ay Radioheliograph (NRH) to observe a J-burst over a broad frequency range (33-173 MHz) on 9 July 2013 at ~11:06 UT. Results. The J-burst showed fundamental and harmonic components and it was associated with a solar jet observed at extreme ultraviolet wavelengths with SDO. The solar jet occurred at a time and location coincident with the radio burst, in the northern hemisphere, and not inside a group of complex active regions in the southern hemisphere. The jet occurred in the negative polarity region of an area of bipolar plage. Newly emerged positive flux in this region appeared to be the trigger of the jet. Conclusions. Magnetic reconnection between the overlying coronal field lines and the newly emerged positive field lines is most likely the cause of the solar jet. Radio imaging provides a clear association between the jet and the J-burst which shows the path of the accelerated electrons., Comment: 11 pages, 8 figures
Published: 2017
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47. Constitutive Modeling of Patterned Liquid Crystal Elastomer for Active Flow Control

Author: Timothy J. White, Michael Settle, Tyler Guin, Richard V. Beblo, and Gregory W. Reich
Subjects: Flow control (fluid), Materials science, Liquid crystal, Liquid crystal elastomer, Separation technology, Active flow control, Crystal structure, Composite material, Anisotropy, Elastomer
Abstract: Patterned liquid crystal elastomer (LCE) has been shown to have significant promise in surface topography control. Large and diverse shapes and surface adaptive responses have been shown using LCE materials with patterned director profiles. Using various techniques, crystal orientation across the surface of the material as well as through the thickness can be achieved yielding the capability to design out-of-plane deformation. These topological features can be used as active flow effectors manipulating, among other things, drag on an object in cross-flow. It is well known that surface topography can have a large effect on skin friction drag by effecting the boundary layer transition, separation, and interfering with the shedding of vortices. In regards to a cylinder in a cross-flow, spatially manipulating surface topography, and thus drag, in this way gives rise to forces exerted by the fluid on the body. An imbalance of forces due to non-uniform surface topography can then be used to control the cylinder. Designing such a system requires optimization of the surface topography via optimization of the crystal orientation pattern over a wide range of environments. Key to this optimization, described in detail in the presented work, is an accurate material model validated against experimental data. By representing the strain energy of the material as a combination of contributions of the elastomer backbone and the liquid crystals separately, unique material properties can be properly modeled. This is achieved by combining a traditional isotropic 3 chain Arruda-Boyce hyperelastic equation modeling the elastomer backbone with an anisotropic extension modeling the patterned liquid crystals, resulting in an anisotropic hyperelastic material model. The model can then be used to predict the material response of various patterns and investigate the design space of possible surface topographies.
Published: 2017
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48. Physical reconfiguration of an origami-inspired deployable microstrip patch antenna array

Author: Edward J. Alanyak, Deanna Sessions, Gregory H. Huff, Philip R. Buskohl, Steven R. Seiler, Sumanna Pallampati, Andrew Gillman, Kazuko Fuchi, Giorgio Bazzan, Gregory W. Reich, and David Grayson
Subjects: Beamforming, Engineering, Reconfigurable antenna, business.industry, Multiphysics, Control reconfiguration, 020206 networking & telecommunications, 02 engineering and technology, Input impedance, Microstrip patch antenna array, 021001 nanoscience & nanotechnology, law.invention, Antenna array, Microstrip antenna, law, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, 0210 nano-technology, business
Abstract: The physical reconfiguration and deployment of a 2×2 corporate-fed microstrip patch antenna array is investigated. The origami-inspired antenna array reconfigures structurally using a Miura-ori fold pattern to deploy to/from a compact folded state from/to a flat state. The impact of folding on the electromagnetic performance is evaluated across a range of physical states to study the impact of physical reconfiguration. In particular, the input impedance and beamforming capabilities are used to characterize the performance as a function of the primary folding parameter. These performance metrics are impacted by a feed network that extends across the folds and the beamforming capabilities that are impacted by the changing element spacing and orientation. Results from simulation and a fabricated structure are provided for a 2.4 GHz design.
Published: 2017
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49. The Fan Region at 1.5 GHz. I: Polarized synchrotron emission extending beyond the Perseus Arm

Author: Bryan Gaensler, T. L. Landecker, A. D. Gray, Marijke Haverkorn, Naomi McClure-Griffiths, M. Wolleben, Ettore Carretti, W. Reich, X. H. Sun, Dominic Schnitzeler, John M. Dickey, S. A. Mao, K. A. Douglas, Alex S. Hill, and J. P. Leahy
Subjects: Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Perseus Arm, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, law.invention, Optics, law, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Physics, 010308 nuclear & particles physics, business.industry, Astronomy and Astrophysics, Plasma, Galactic plane, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Synchrotron, Galaxy, Magnetic field, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), business
Abstract: The Fan Region is one of the dominant features in the polarized radio sky, long thought to be a local (distance < 500 pc) synchrotron feature. We present 1.3-1.8 GHz polarized radio continuum observations of the region from the Global Magneto-Ionic Medium Survey (GMIMS) and compare them to maps of Halpha and polarized radio continuum intensity from 0.408-353 GHz. The high-frequency (> 1 GHz) and low-frequency (< 600 MHz) emission have different morphologies, suggesting a different physical origin. Portions of the 1.5 GHz Fan Region emission are depolarized by about 30% by ionized gas structures in the Perseus Arm, indicating that this fraction of the emission originates >2 kpc away. We argue for the same conclusion based on the high polarization fraction at 1.5 GHz (about 40%). The Fan Region is offset with respect to the Galactic plane, covering -5�� < b < +10��; we attribute this offset to the warp in the outer Galaxy. We discuss origins of the polarized emission, including the spiral Galactic magnetic field. This idea is a plausible contributing factor although no model to date readily reproduces all of the observations. We conclude that models of the Galactic magnetic field should account for the > 1 GHz emission from the Fan Region as a Galactic-scale, not purely local, feature., Accepted to MNRAS
Published: 2017
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50. Gust prediction via artificial hair sensor array and neural network

Author: Kaman Thapa Magar, Richard V. Beblo, Gregory W. Reich, and Alexander M. Pankonien
Subjects: 0209 industrial biotechnology, Turbulence, Computer science, Angle of attack, Airspeed, Feed forward, 02 engineering and technology, Aerodynamics, 021001 nanoscience & nanotechnology, Aerodynamic force, Moment (mathematics), Lift (force), 020901 industrial engineering & automation, Recurrent neural network, Flight dynamics, Sensor array, Pitching moment, 0210 nano-technology, Excitation, Simulation
Abstract: Gust Load Alleviation (GLA) is an important aspect of flight dynamics and control that reduces structural loadings and enhances ride quality. In conventional GLA systems, the structural response to aerodynamic excitation informs the control scheme. A phase lag, imposed by inertia, between the excitation and the measurement inherently limits the effectiveness of these systems. Hence, direct measurement of the aerodynamic loading can eliminate this lag, providing valuable information for effective GLA system design. Distributed arrays of Artificial Hair Sensors (AHS) are ideal for surface flow measurements that can be used to predict other necessary parameters such as aerodynamic forces, moments, and turbulence. In previous work, the spatially distributed surface flow velocities obtained from an array of artificial hair sensors using a Single-State (or feedforward) Neural Network were found to be effective in estimating the steady aerodynamic parameters such as air speed, angle of attack, lift and moment coefficient. This paper extends the investigation of the same configuration to unsteady force and moment estimation, which is important for active GLA control design. Implementing a Recurrent Neural Network that includes previous-timestep sensor information, the hair sensor array is shown to be capable of capturing gust disturbances with a wide range of periods, reducing predictive error in lift and moment by 68% and 52% respectively. The L2 norms of the first layer of the weight matrices were compared showing a 23% emphasis on prior versus current information. The Recurrent architecture also improves robustness, exhibiting only a 30% increase in predictive error when undertrained as compared to a 170% increase by the Single-State NN. This diverse, localized information can thus be directly implemented into a control scheme that alleviates the gusts without waiting for a structural response or requiring user-intensive sensor calibration.
Published: 2017
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