1,748 research outputs found
Characterisation of the Etching Quality in Micro-Electro-Mechanical Systems by Thermal Transient Methodology
Our paper presents a non-destructive thermal transient measurement method
that is able to reveal differences even in the micron size range of MEMS
structures. Devices of the same design can have differences in their
sacrificial layers as consequence of the differences in their manufacturing
processes e.g. different etching times. We have made simulations examining how
the etching quality reflects in the thermal behaviour of devices. These
simulations predicted change in the thermal behaviour of MEMS structures having
differences in their sacrificial layers. The theory was tested with
measurements of similar MEMS devices prepared with different etching times. In
the measurements we used the T3Ster thermal transient tester equipment. The
results show that deviations in the devices, as consequence of the different
etching times, result in different temperature elevations and manifest also as
shift in time in the relevant temperature transient curves.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
A Novel Protocol-Authentication Algorithm Ruling Out a Man-in-the-Middle Attack in Quantum Cryptography
In this work we review the security vulnerability of Quantum Cryptography
with respect to "man-in-the-middle attacks" and the standard authentication
methods applied to counteract these attacks. We further propose a modified
authentication algorithm which features higher efficiency with respect to
consumption of mutual secret bits.Comment: 4 pages, submitted to the International Journal of Quantum
Information, Proceedings of the meeting "Foundations of Quantum Information",
Camerino, April 200
FM 047-02: a collisional pair of galaxies with a ring
Aims. We investigate the nature of the galaxy pair FM 047-02, which has been
proposed as an archetype of the Solitaire types of peculiar (collisional) ring
galaxies. Methods. The study is based on long-slit spectrophotometric data in
the range of 3500-9500 angstrons obtained with the Gemini Multi-ObjectComment: 07 pages, 06 figures, 02 tables. arXiv admin note: text overlap with
arXiv:1206.071
Practical Quantum Key Distribution with Polarization-Entangled Photons
We present an entangled-state quantum cryptography system that operated for
the first time in a real world application scenario. The full key generation
protocol was performed in real time between two distributed embedded hardware
devices, which were connected by 1.45 km of optical fiber, installed for this
experiment in the Vienna sewage system. The generated quantum key was
immediately handed over and used by a secure communication application.Comment: 5 pages, 3 figure
Discrete structure of ultrathin dielectric films and their surface optical properties
The boundary problem of linear classical optics about the interaction of
electromagnetic radiation with a thin dielectric film has been solved under
explicit consideration of its discrete structure. The main attention has been
paid to the investigation of the near-zone optical response of dielectrics. The
laws of reflection and refraction for discrete structures in the case of a
regular atomic distribution are studied and the structure of evanescent
harmonics induced by an external plane wave near the surface is investigated in
details. It is shown by means of analytical and numerical calculations that due
to the existence of the evanescent harmonics the laws of reflection and
refraction at the distances from the surface less than two interatomic
distances are principally different from the Fresnel laws. From the practical
point of view the results of this work might be useful for the near-field
optical microscopy of ultrahigh resolution.Comment: 25 pages, 16 figures, LaTeX2.09, to be published in Phys.Rev.
Grid-Free 2D Plasma Simulations of the Complex Interaction Between the Solar Wind and Small, Near-Earth Asteroids
We present results from a new grid-free 2D plasma simulation code applied to a small, unmagnetized body immersed in the streaming solar wind plasma. The body was purposely modeled as an irregular shape in order to examine photoemission and solar wind plasma flow in high detail on the dayside, night-side, terminator and surface-depressed 'pocket' regions. Our objective is to examine the overall morphology of the various plasma interaction regions that form around a small body like a small near-Earth asteroid (NEA). We find that the object obstructs the solar wind flow and creates a trailing wake region downstream, which involves the interplay between surface charging and ambipolar plasma expansion. Photoemission is modeled as a steady outflow of electrons from illuminated portions of the surface, and under direct illumination the surface forms a non-monotonic or ''double-sheath'' electric potential upstream of the body, which is important for understanding trajectories and equilibria of lofted dust grains in the presence of a complex asteroid geometry. The largest electric fields are found at the terminators, where ambipolar plasma expansion in the body-sized night-side wake merges seamlessly with the thin photoelectric sheath on the dayside. The pocket regions are found to be especially complex, with nearby sunlit regions of positive potential electrically connected to unlit negative potentials and forming adjacent natural electric dipoles. For objects near the surface, we find electrical dissipation times (through collection of local environmental solar wind currents) that vary over at least 5 orders of magnitude: from 39 Micro(s) inside the near-surface photoelectron cloud under direct sunlight to less than 1 s inside the particle-depleted night-side wake and shadowed pocket region
Comparison of Two Low-Power Electronic Interfaces for Capacitive Mems Sensors
The paper discusses the importance and the issues of interfacing capacitive
sensors. Two architectures applicable for interfacing capacitive sensors are
presented. The first solution was designed to interface a capacitive humidity
sensor designed and built for a humidity-dependent monolithic capacitor
developed at Budapest University of Technology and Economics. The second case
presents the possible read-out solutions for a SOI-MEMS accelerometer. Both of
the architectures were built and tested in a discrete implementation to qualify
the methods before the integrated realization. The paper presents a detailed
comparison of the two methodsComment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
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