oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Contactless Area Measurement (Contactless Planimeter)
V. Ricny,P. Stancik
Radioengineering , 2008,
Abstract: The paper describes the designed hardware and software systems (so-called planimeters) for contactless measurement of areas (eventually geometric distances between two selected points) of planar projections of various objects. These systems operate on the principle of processing the video signal scanned by a digital camera (or TV camera).
Evaluation of Contactless Smartcard Antennas  [PDF]
Michael Roland,Michael H?lzl
Computer Science , 2015,
Abstract: This report summarizes the results of our evaluation of antennas of contactless and dual interface smartcards and our ideas for user-switchable NFC antennas. We show how to disassemble smartcards with contactless capabilities in order to obtain the bare chip module and the bare antenna wire. We examine the design of various smartcard antennas and present concepts to render the contactless interface unusable. Finally, we present ideas and practical experiments to make the contactless interface switchable by the end-user.
Ultrasound-induced acoustophoretic motion of microparticles in three dimensions  [PDF]
Peter B. Muller,Massimiliano Rossi,Alvaro G. Marin,Rune Barnkob,Per Augustsson,Thomas Laurell,Christian J. Kaehler,Henrik Bruus
Physics , 2013, DOI: 10.1103/PhysRevE.88.023006
Abstract: We derive analytical expressions for the three-dimensional (3D) acoustophoretic motion of spherical microparticles in rectangular microchannels. The motion is generated by the acoustic radiation force and the acoustic streaming-induced drag force. In contrast to the classical theory of Rayleigh streaming in shallow, infinite, parallel-plate channels, our theory does include the effect of the microchannel side walls. The resulting predictions agree well with numerics and experimental measurements of the acoustophoretic motion of polystyrene spheres with nominal diameters of 0.537 um and 5.33 um. The 3D particle motion was recorded using astigmatism particle tracking velocimetry under controlled thermal and acoustic conditions in a long, straight, rectangular microchannel actuated in one of its transverse standing ultrasound-wave resonance modes with one or two half-wavelengths. The acoustic energy density is calibrated in situ based on measurements of the radiation dominated motion of large 5-um-diam particles, allowing for quantitative comparison between theoretical predictions and measurements of the streaming induced motion of small 0.5-um-diam particles.
Contactless inductive flow tomography  [PDF]
Frank Stefani,Thomas Gundrum,Gunter Gerbeth
Physics , 2004, DOI: 10.1103/PhysRevE.70.056306
Abstract: The three-dimensional velocity field of a propeller driven liquid metal flow is reconstructed by a contactless inductive flow tomography (CIFT). The underlying theory is presented within the framework of an integral equation system that governs the magnetic field distribution in a moving electrically conducting fluid. For small magnetic Reynolds numbers this integral equation system can be cast into a linear inverse problem for the determination of the velocity field from externally measured magnetic fields. A robust reconstruction of the large scale velocity field is already achieved by applying the external magnetic field alternately in two orthogonal directions and measuring the corresponding sets of induced magnetic fields. Kelvin's theorem is exploited to regularize the resulting velocity field by using the kinetic energy of the flow as a regularizing functional. The results of the new technique are shown to be in satisfactory agreement with ultrasonic measurements.
Ion Beam Shepherd for Contactless Space Debris Removal  [PDF]
C. Bombardelli,J. Pelaez
Physics , 2011,
Abstract: A novel concept for contactless active removal of large space debris is proposed exploiting the use of a high-speed targeted ion beam. The ion beam shepherd spacecraft (IBS) is equipped with an electric propulsion system generating a quasi-neutral plasma pointed against the space debris to remotely modify its orbit without physical contact with the latter. The beam shepherd must be equipped with a secondary propulsion system which counteracts the reaction force exerted by the ion beam hence keeping the distance between the space debris constant throughout the deorbit (or reorbit) process. A preliminary analysis of the concept is provided highlighting the expected performance and the main technologicals challenges. The concept has the potential of making large debris removal operations possible in the near future.
Ari Folman’s Waltz With Bashir and the Limits of Abstract Tragedy  [cached]
Nicholas Hetrick
Image and Narrative : Online Magazine of the Visual Narrative , 2010,
Abstract: (E): Drawing on scholarship on film cognition, the essay argues that Ari Folman's animated documentary Waltz with Bashir effectively recreates the process of recovering memories by capitalizing on the way our brains process films, and by thematizing memory. However, the film's limited contextualization of the 1982 Lebanon War and the lives of the soldiers involved and depicted limits Waltz's ability to make an effective antiwar statement. While the film's impact is not limited to viewers with knowledge of the particular politico-military conflict the film represents, it is limited by the nature and extent of its involvement with its subjects' lives before and after the war. (F): S’inspirant des recherches en cognition cinématographique, cet article démontre que le documentaire animé d’Ari Folman, Valse avec Bashir, recrée vraiment le processus de la mémoire retrouvée en exploitant la manière dont notre cerveau traite les images filmiques, puis en thématisant la mémoire. Toutefois, la contextualisation très partielle de la guerre du Liban de 1982 et les vies des soldats impliqués et représentés dans le film limitent les possibilités de Valse avec Bashir de se transformer en une uvre vraiment pacifiste. Certes, l’impact du film n’est pas limité aux spectateurs connaissant la situation politico-militaire décrite par le film. Ses limites sont tout autres et elles sont déterminées par la nature et l’étendue de l’engagement avec les vies des personnages avant et après la guerre.
Contactless Thermal Characterization of High Temperature Test Chamber  [PDF]
Z. Szucs,G. Bognar,Vladimir Szekely,M. Rencz
Computer Science , 2008,
Abstract: In this paper the methodology and the results of a contactless thermal characterization of a high temperature test chamber will be introduced. The test chamber is used for fatigue testing of different MEMS devices where the homogenous temperature distribution within the close proximity from the heating filaments is very important. Our aim was to characterize the evolving temperature distribution inside the test chamber. In order to achieve smaller time constant a new contactless sensor card was developed. The contactless thermal characterization method introduced in this paper enables in situ heat distribution measurement inside the test chamber during operation, with the detection of potentially uneven heat distribution.
Contactless photoconductivity measurements on (Si) nanowires  [PDF]
A. D. Chepelianskii,F. Chiodi,M. Ferrier,S. Gueron,E. Rouviere,H. Bouchiat
Physics , 2009, DOI: 10.1063/1.3280057
Abstract: Conducting nanowires possess remarkable physical properties unattainable in bulk materials. However our understanding of their transport properties is limited by the difficulty of connecting them electrically. In this Letter we investigate phototransport in both bulk silicon and silicon nanowires using a superconducting multimode resonator operating at frequencies between 0.3 and 3 GHz. We find that whereas the bulk Si response is mainly dissipative, the nanowires exhibit a large dielectric polarizability. This technique is contactless and can be applied to many other semiconducting nanowires and molecules. Our approach also allows to investigate the coupling of electron transport to surface acoustic waves in bulk Si and to electro-mechanical resonances in the nanowires.
Novel Principle of Contactless Gauge Block Calibration  [PDF]
Zdeněk Buchta,?imon ?e?ucha,B?etislav Mikel,Martin ?í?ek,Josef Lazar,Ond?ej ?íp
Sensors , 2012, DOI: 10.3390/s120303350
Abstract: In this paper, a novel principle of contactless gauge block calibration is presented. The principle of contactless gauge block calibration combines low-coherence interferometry and laser interferometry. An experimental setup combines Dowell interferometer and Michelson interferometer to ensure a gauge block length determination with direct traceability to the primary length standard. By monitoring both gauge block sides with a digital camera gauge block 3D surface measurements are possible too. The principle presented is protected by the Czech national patent No. 302948.
Structuralisme et néoréalisme dans le champ des relations internationales. Le cas de Kenneth Waltz Structuralism and new realism in the field of international relations. The case of Kenneth Waltz  [cached]
Alexis Cartonnet
Astérion , 2011,
Abstract: Cet article esquisse un rapprochement entre un courant de pensée politique, le néoréalisme, et une méthode en sciences humaines, le structuralisme. Ce courant et cette méthode ont suivi des trajectoires séparées, de l’après-guerre à la fin des années soixante-dix, jusqu’à ce que Kenneth Waltz croise ces deux problématiques. Après avoir défini respectivement réalisme et structuralisme, cet article établit leur connexion et tente d’éclairer les raisons pour lesquelles ce rapprochement n’avait pas été conduit jusqu’alors. This article is an attempt to link the study of a political thought movement, neorealism, with a social sciences methodology, structuralism. Both currents have followed different paths, throughout the period that lasted from after the Second World War to the end of the seventies, until Kenneth Waltz made them match in 1979. After defining both neorealism and structuralism, this paper tries to connect them, and thus understand the reasons why the parallelism wasn’t made until then.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.