International Journal of Acoustics and Vibration, Vol
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Sprachrohr Heft 58
Sprachrohr Heft 58 ‐ Juni 2012 Vorschau AIA‐DAGA 2013 3 DEGA aktuell 6. DEGA‐Symposium 11 Mitgliederversammlung 11 Tag gegen Lärm 19 Ehrungen Helmholtz‐Medaille 24 Lothar‐Cremer‐Preis 28 DEGA‐Studienpreis 30 Helmholtz‐Medaille für Weitere Ehrungen 31 Prof. Wolfgang Fasold Fachausschüsse / Fachgruppen Lothar‐Cremer‐Preis für Arbeitsring Lärm der DEGA 34 Dr. Franz Zotter Bau‐ und Raumakustik 35 Elektroakustik 35 Fahrzeugakustik 37 Hörakustik 39 Lärm: Wirkungen und Schutz 42 Musikalische Akustik 42 Physikalische Akustik 44 Strömungsakustik 44 Ultraschall 45 DEGA‐Akademie 47 Aktuelles in Kürze 49 Publikationen 54 Geschichte der Akustik: Mitglieder / Fördermitglieder 57 Impressum / Kontakte 61 Heft 4 erschienen herausgegeben von der Deutschen Gesellschaft für Akustik e.V. AIA‐DAGA 2013 Vorschau AIA‐DAGA 2013 Die AIA‐DAGA 2013 ist Teil der Kon‐ ferenzreihe „Euroregio” der European Acoustics Association (EAA) und umfasst die 39. Deutsche und .die 40 Italienische Jahrestagung für Akustik und wird unterstützt von der Österrei‐ chischen (AAA) und der Schweize‐ rischen Gesellschaft für Akustik (SGA‐ SSA) sowie der Landesagentur für Umwelt / Autonome Provinz Bozen Südtirol. Nach vier Tagungen in Österreich 1990, in der Schweiz 1998, in Frank‐ reich 2004 und in den Niederlanden AIA‐DAGA 2013 2009 setzt die DEGA damit die erfolg‐ reiche Reihe von Gemeinschaftstagun‐ Gemeinschaftstagung für Akustik gen mit benachbarten akustischen EAA Euroregio, 18.‐21. März 2013 Gesellschaften fort. Auch bei der AIA‐ DAGA 2013 werden die Organisatoren einschließlich: mit allen Kräften für eine attraktive • 40. Italienische Jahrestagung für und ereignisreiche Tagung sorgen. Akustik (AIA) So werden u. a. in sechs Plenarvorträ‐ • 39. Deutsche Jahrestagung für gen aktuelle Trends und künftige Ent‐ Akustik (DAGA) wicklungen zu zentralen Fragen der Akustik aufgezeigt. -
Dynamic Manipulation of Mechanical Resonators in the High Amplitude Regime Through Optical Backaction
Dynamic manipulation of mechanical resonators in the high amplitude regime through optical backaction Mahmood Bagheri, Menno Poot, Mo Li, Wolfram P. H. Pernice, Hong X. Tang Department of Electrical Engineering, Yale University, New Haven, CT 06511 Cavity optomechanics enables active manipulation of mechanical resonators through backaction cooling and amplification1,2. This ability to control mechanical motion with retarded optical forces has recently spurred a race towards realizing a mechanical resonator in its quantum ground state3,4,5,6,7,8,9. Here, instead of quenching optomechanical motion, we demonstrate high amplitude operation of nanomechanical resonators by utilizing a highly efficient phonon generation process. In this regime, the nanomechanical resonators gain sufficient energy from the optical field to overcome the large energy barrier of a double well potential, leading to nanomechanical slow-down and zero frequency singularity, as predicted by early theories10. Besides fundamental studies and interests in parametric amplification of small forces11, optomechanical backaction is also projected to open new windows for studying discrete mechanical states12,13 and to foster applications14,15,16,17. Here we realize a non-volatile mechanical memory element, in which bits are written and reset via optomechanical backaction by controlling the mechanical damping across the barrier. Our study casts a new perspective on the energy dynamics in coupled mechanical resonator – cavity systems and enables novel functional devices that utilize the principles of cavity optomechanics. Classical and quantum dynamics of nanomechanical systems promise new applications in nanotechnology18,19 and fundamental tests of quantum mechanics in mesoscopic objects2,9. Recent development of nanoscale electromechanical (NEMS) and optomechanical systems has enabled cooling of mechanical systems to their quantum ground state7,8, which brings the possibility of quantum information processing with mechanical devices20,21. -
A Layer Model of Sound Quality
3rd International Workshop on Perceptual Quality of Systems (PQS 2010) 6-8 September 2010, Bautzen, Germany A Layer Model of Sound Quality Jens Blauert 1, Ute Jekosch 2 1 Institute of Communication Acoustics, Ruhr-University Bochum, Germany 2 Chair for Communication Acoustics, Technical University Dresden, Germany [email protected] Abstract There is indeed a wide agreement that − in congruence with Sound-quality is a complex and multi-layered phenomenon the classical trialism of soul, body and mind − there are three [1]. When analysing or modelling the formation process of basic kinds of percepts that our perceptual world is essentially sound-quality judgements, a variety of quality elements and composed of. Following [7], they may be denoted feelings, quality features [2] have to be taken into account, whereby the things and concepts. actual relevance and salience of each of them is situation dependent. In this paper, we present some ideas with the aim • Feelings (e.g., hunger, fear, pain, sadness, joy) are of structuring the quality-formation process into different lay- linked to processes inside the human body (incl. ers according to the degree of abstraction involved. Depending subcutane ones) and they usually are also perceptu- ally localized just there. on this degree, different sets of references and evaluation and assessment methods have to be employed. • Things (sensations) are percepts which are related to Index Terms: sound-quality assessment, abstraction level the sensory organs. In audition we usually call them auditory -
Tuning the Resonant Frequency and Damping of an Electromagnetic Energy Harvester Using Power Electronics Paul D
Tuning the Resonant Frequency and Damping of an Electromagnetic Energy Harvester Using Power Electronics Paul D. Mitcheson Member, IEEE, Tzern T. Toh, Kwok H. Wong, Steve G. Burrow Member, IEEE and Andrew S. Holmes Member, IEEE Abstract—In order to maximize power density, the resonant magnetic transduction mechanism (represented by a parasitic frequency of an energy harvester should be equal to the source inductance and resistance, Larm and Rarm, respectively, and excitation frequency and the electrical damping set equal to a transformer). The resistor, inductor and capacitor on the the parasitic damping. These parameters should be adjustable during device operation because the excitation characteristics can primary-side of the transformer represent parasitic damping change. This brief presents, for the first time, a power electronic Dp, spring constant k, and proof mass, m, respectively. A interface that is capable of continual adjustment of the damping resistor, RL, is connected to the secondary windings to form and the resonant frequency of an energy harvester by controlling a typical electrical load, and its value determines the electrical real and reactive power exchange between the electrical and damping of the transducer and therefore the generated power mechanical domains while storing the harvested energy in a bat- tery. The advantages of this technique over previously proposed for a given source excitation of frequency ω and amplitude Y0. methods are the precise control over the tuning parameters of the Clearly, the addition of the reactive components, LL and CL electrical system and integrated rectification within the tuning in Fig. 1 is also possible, and the reason for this is explained interface. -
The Role of Mechanical Resonance in Physiological Tremor
THE ROLE OF MECHANICAL RESONANCE IN PHYSIOLOGICAL TREMOR by CARLIJN ANDREA VERNOOIJ A thesis submitted to The University of Birmingham for the degree of DOCTOR OF PHILOSOPHY School of Sport, Exercise & Rehabilitation Sciences College of Life and Environmental Sciences University of Birmingham December 2013 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. ABSTRACT The origin of physiological tremor has been studied for many years. Several central and spinal mechanisms which provide an oscillatory input to the muscles have been proposed. Nevertheless, any neural control signal inevitably has to work upon a resonant peripheral system involving the series-coupled elastic muscle-tendon complex and the inertia of the limb. In this thesis I look into the potential role for mechanical resonance to explain tremor. First, I show that the resonant component of hand tremor depends on the velocity of hand movement. Movement reduces muscle stiffness (a process called muscle thixotropy) and the tremor frequency falls. Second, I demonstrate that rhythmic tremor is abolished when eliminating resonance by recording tremor in isometric conditions. Third, I replaced EMG by an artificial drive. -
In April 1831, a Brigade of Soldiers Marched in Step Across England's Broughton Suspension Bridge
In April 1831, a brigade of soldiers marched in step across England's Broughton Suspension Bridge. According to accounts of the time, the bridge broke apart beneath the soldiers, throwing dozens of men into the water. After this happened, the British Army reportedly sent new orders: Soldiers crossing a long bridge must "break stride," or not march in unison, to stop such a situation from occurring again. Structures like bridges and buildings, although they appear to be solid and immovable, have a natural frequency of vibration within them. A force that's applied to an object at the same frequency as the object's natural frequency will amplify the vibration of the object in an occurrence called mechanical resonance. Sometimes your car shakes hard when you hit a certain speed, and a girl on a swing can go higher with little effort just by swinging her legs. The same principle of mechanical resonance that makes these incidents happen also works when people walk in lockstep across a bridge. If soldiers march in unison across the structure, they apply a force at the frequency of their step. If their frequency is closely matched to the bridge's frequency, the soldiers' rhythmic marching will amplify the vibrational frequency of the bridge. If the mechanical resonance is strong enough, the bridge can vibrate until it collapses from the movement. A potent reminder of this was seen in June 2000, when London's Millennium Bridge opened to great fanfare. As crowds packed the bridge, their footfalls made the bridge vibrate slightly. "Many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them," according to a 2005 report in Nature. -
Mechanical Stabilisation of Superconducting Quarter Wave Resonators A
MECHANICAL STABILISATION OF SUPERCONDUCTING QUARTER WAVE RESONATORS A. Facco, INFN- Laboratori Nazionali di Legnaro, via Romea 4, 35020 Legnaro (Padova) Italy; V. Zviagintsev, ITEP, B. Cheremushkinskaya 25, Moscow,117259, Russia. Abstract in the case of white noise; on the other hand, when a 42 Hz mechanical vibration is applied for a long enough A device which is capable to reduce significantly the time, the frequency error can reach such an amplitude amplitude of mechanical vibrations in superconducting that the phase-lock system capabilities are exceeded. In quarter wave resonators was designed, constructed and the ALPI linac cryostats this condition can appear, for a tested. This device can eliminate the necessity of fast few minutes, almost everyday; this could make the tuners and related electronics in many superconducting operation of many resonators at the same time cavities, resulting in a significant cost saving both in the problematic. We have exploited a new approach to this construction and in the operation of superconducting low problem: we have added to the resonator a mechanical beta linacs. dissipator, capable to absorb energy from the dangerous mechanical mode and, consequently, to reduce its 1 INTRODUCTION amplitude. One problem in this approach is the difficulty Mechanical stability is a very important requirement in of building a device with a linear, or at least smooth, superconducting cavities; their very small rf bandwidth, a response at liquid helium temperature; another problem is consequence of their very high quality factor, makes very that new resonant modes could be easily introduced by difficult to lock them to an external frequency, requiring adding to the resonator new parts. -
Tuning of a Vibration Absorber with Shunted Piezoelectric Transducers
Arch Appl Mech (2016) 86:1715–1732 DOI 10.1007/s00419-014-0972-5 SPECIAL Oliver Heuss · Rogério Salloum · Dirk Mayer · Tobias Melz Tuning of a vibration absorber with shunted piezoelectric transducers Received: 16 December 2013 / Accepted: 19 November 2014 / Published online: 13 December 2014 © The Author(s) 2014. This article is published with open access at Springerlink.com Abstract In order to reduce structural vibrations in narrow frequency bands, tuned mass absorbers can be an appropriate measure. A quite similar approach which makes use of applied piezoelectric elements, instead of additional oscillating masses, are the well-known resonant shunts, consisting of resistances, inductances, and possibly negative capacitances connected to the piezoelectric element. This paper presents a combined approach, which is based on a conventional tuned mass absorber, but whose characteristics can be strongly influenced by applying shunted piezoceramics. Simulations and experimental analyses are shown to be very effective in predicting the behavior of such electromechanical systems. The vibration level of the absorber can be strongly attenuated by applying different combinations of resistant, resonant, and negative capacitance shunt circuits. The damping characteristics of the absorber can be changed by applying a purely resistive or resonant resistant shunt. Additionally, the tuning frequency of the absorber can be adapted to the excitation frequency, using a negative capacitance shunt circuit, which requires only the energy to supply the electric components. Keywords Shunt damping · Tuned mass absorber · Active vibration control · Semi-active · Frequency tuning 1 Introduction Tuned vibration absorbers [1] are common means of vibration reduction in many technical applications. Basically, those devices are single degree of freedom oscillators comprising of a spring-damper element and of an inertial mass. -
Schriftkulturen Der Musik
["NOTIZBUCH PHONOGRAPHIE UND TECHNISCHEN STIMMEN"] Phonotechnische Vorspiele Ursprung der Phonographie aus der Messung Der Phonograph als technisches Artefakt Das Grammophon Direktschneidegeräte Die Schallplatte Vorschleifspuren Transduktion "Fülle des Wohllauts" Entkörperlichung der Stimme Rilkes "Urgeräusch" Die Stimme des Kaisers Schallkonservierung Schallwandlung Schrift versus EM Feld (Schallplatte / Tonband) Sonagramm / Sonographie (Phonautograph, Oszilloskop) Ursprung des Phonographen aus dem Geist der Signalübertragung Die Appellstruktur des Vokalalphabets David Kaufmann, Der Phonograph und die Blinden, 1899 Vokalalphabetische Phonographie / Phonographen Der Phonograph, technisch Bruch technologischer Medien mit der Schrift Phonographie, Afrikanistik und Musikethnologie Die Geburt phonographischer Meßmedien aus der Phonetik Stimme und Schrift mit W. v. Humboldt und mit de Saussure Technische Lesarten Avdo, kinematographisch Phonographé: Der Unterschied zwischen Phonograph und Magnetophon "Akustische Geschichtsschreibung"? Die presidential tapes Technische Schriften als Klanganalyse: das Oszilloskop Stimmzeugenschaft: Sirenen grammophon Stumpfs vokalanalytische Meßmedien Schallübertragung (Helmholtz) Seelen sprechen in Wachs. Exkurs zur Phonautographie Historie versus (Medien-)Archäologie des Auditiven Absenz versus Appräsentierung: Phonographisch induzierte Halluzination von Vergangenheit Phonozentrismus um 1800 Nietzsche grammophon Schallkonservierung Techno-Ethnographie des futurum exactum Archäologie Der Phonograph Klangkörper -
Final Catalogue
Price Sub Price Qty. Seq. ISBN13 Title Author Category Year After Category USD Needed 70% 1 9780387257099 Accounting and Financial System Robert W. McGee, Barry University, Miami Shores, FL, USA; Galina Accounting Auditing 2006 125 38 Reform in Eastern Europe and Asia G. Preobragenskaya, Omsk State University, Omsk, Russia 2 9783540308010 Regulatory Risk and the Cost of Capital Burkhard Pedell, University of Stuttgart, Germany Accounting Auditing 2006 115 35 3 9780387265971 Economics of Accounting Peter Ove Christensen, University of Aarhus, Aarhus C, Denmark; Accounting Auditing 2005 149 45 Gerald Feltham, The University of British Columbia, Faculty of Commerce & Business Administration 4 9780387238470 Accounting and Financial System Robert W. McGee, Barry University, Miami Shores, FL, USA; Galina Accounting Auditing 2005 139 42 Reform in a Transition Economy: A G. Preobragenskaya, Omsk State University, Omsk, Russia Case Study of Russia 5 9783540408208 Business Intelligence Techniques Murugan Anandarajan, Drexel University, Philadelphia, PA, USA; Accounting Auditing 2004 145 44 Asokan Anandarajan, New Jersey Institute of Technology, Newark, NJ, USA; Cadambi A. Srinivasan, Drexel University, Philadelphia, PA, USA (Eds.) 6 9780387239323 Economics of Accounting Peter O. Christensen, University of Southern Denmark-Odense, Accounting Special 2003 85 25 Denmark; G.A. Feltham, University of British Columbia, Vancouver, Topics BC, Canada 7 9781402072291 Economics of Accounting Peter O Christensen, University of Southern Denmark-Odense, Accounting Auditing 2002 185 56 Denmark; G.A. Feltham, Faculty of Commerce and Business Administration, University of British Columbia, Vancouver, Canada 8 9780792376491 The Audit Committee: Performing Laura F. Spira Accounting Special 2002 175 53 Corporate Governance Topics 9 9781846280207 Adobe® Acrobat® and PDF for Tom Carson, New Economy Institute, Chattanooga, TN 37403, USA.; Architecture Design, 2006 85 25 Architecture, Engineering, and Donna L. -
Frequency Tuning of Vibration Absorber Using Topology
FREQUENCY TUNING OF VIBRATION ABSORBER USING TOPOLOGY OPTIMIZATION by SWAPNIL SUBHASH HAREL Presented to the Faculty of the Graduate School of The University of Texas at Arlington in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE IN MECHANICAL ENGINEERING THE UNIVERSITY OF TEXAS AT ARLINGTON Copyright © by Swapnil Subhash Harel 2017 All Rights Reserved 2 Acknowledgements I would like to express my gratitude towards Dr. Robert Taylor for guiding and helping me throughout my thesis research. He always had time to discuss my work and helped solve any problem that I faced during my research work. I would like to thank Dr. Bo Wang for constantly supporting my research work with his ideas which were second to none. I would also like to thank Dr, Kent Lawrence for finding time out of their busy schedule to serve on my thesis defense committee. Lastly, I would like to thank my family. I would especially like to support my father, Subhash Harel, my mother Surekha Harel and my younger sister Apurva Harel for their support all these years. It was their continued support and belief that I have been able to do all that I have done so far. I would also like to offer regards to all those who have supported or helped me in any regards this period. May 04, 2017 3 Abstract FREQUENCY TUNING OF VIBRATION ABSORBER USING TOPOLOGY OPTIMIZATION by Swapnil Subhash Harel, MS The University of Texas at Arlington, 2017 Supervising Professors: Dr. Robert Taylor and Dr. Bo Wang A tuned mass absorber is a system for reducing the amplitude in one oscillator by coupling it to a second oscillator. -
Modulation of Mechanical Resonance by Chemical Potential Oscillation in Graphene
LETTERS PUBLISHED ONLINE: 7 DECEMBER 2015 | DOI: 10.1038/NPHYS3576 Modulation of mechanical resonance by chemical potential oscillation in graphene Changyao Chen1†, Vikram V. Deshpande2, Mikito Koshino3, Sunwoo Lee4, Alexander Gondarenko1, Allan H. MacDonald5, Philip Kim6 and James Hone1* The classical picture of the force on a capacitor assumes a investigated. Understanding the corrections to the classical model large density of electronic states, such that the electrochemical is of fundamental interest and important for modelling of nano- potential of charges added to the capacitor is given by mechanical systems in the atomically thin limit3,4. Here we examine the external electrostatic potential and the capacitance is the case of a resonant nano-mechanical device, and show that the determined purely by geometry1. Here we consider capacitively first-order correction to the resonant frequency consists of three driven motion of a nano-mechanical resonator with a low terms: one term proportional to µ and the other two proportional density of states, in which these assumptions can break to its derivative dµ/dn, with the latter represented through the in- 2–5 −1 D. = 2/. µ/ down . We find three leading-order corrections to the verse quantum capacitance CQ 1 Ae d dn)(A is the sample classical picture: the first of which is a modulation in the size and e is the electron charge). The phenomenon is explored static force due to variation in the internal chemical potential; experimentally by examining the behaviour of a graphene resonator, the second and third are changes in the static force and in which µ is tuned by a perpendicular magnetic field B at a dynamic spring constant due to the rate of change of chemical fixed electrochemical potential.