12,561 research outputs found
The Replication Argument for Incompatibilism
In this paper, I articulate an argument for incompatibilism about moral responsibility and determinism. My argument comes in the form of an extended story, modeled loosely on Peter van Inwagenâs ârollback argumentâ scenario. I thus call it âthe replication argument.â As I aim to bring out, though the argument is inspired by so-called âmanipulationâ and âoriginal designâ arguments, the argument is not a version of either such argumentâand plausibly has advantages over both. The result, I believe, is a more convincing incompatibilist argument than those we have considered previously
JT9D jet engine performance deterioration
The analytical techniques utilized to examine the effects of flight loads and engine operating conditions on performance deterioration are presented. The role of gyroscopic, gravitational, and aerodynamic loads are shown along with the effect of variations in engine build clearances. These analytical results are compared to engine test data along with the correlation between analytically predicted and measured clearances and rub patterns. Conclusions are drawn and important issues are discussed
An optimal Mars Trojan asteroid search strategy
Trojan asteroids are minor planets that share the orbit of a planet about the
Sun and librate around the L4 or L5 Lagrangian points of stability. Although
only three Mars Trojans have been discovered, models suggest that at least ten
times this number should exist with diameters >= 1 km. We derive a model that
constrains optimal sky search areas and present a strategy for the most
efficient use of telescope survey time that maximizes the probability of
detecting Mars Trojans. We show that the Gaia space mission could detect any
Mars Trojans larger than 1 km in diameter, provided the relative motion
perpendicular to Gaia's CCD array is less than 0.40 arcsec per second.Comment: 6 pages, 6 figures, 3 tables, accepted for publication in MNRAS.
arXiv admin note: substantial text overlap with arXiv:1111.112
Detection of inner Solar System Trojan Asteroids by Gaia
The Gaia satellite, planned for launch by the European Space Agency (ESA) in
2013, is the next generation astrometry mission following Hipparcos. While
mapping the whole sky, the Gaia space mission is expected to discover thousands
of Solar System Objects. These will include Near-Earth Asteroids and objects at
Solar elongations as low as 45 degrees, which are difficult to observe with
ground-based telescopes. We present the results of simulations for the
detection of Trojan asteroids in the orbits of Earth and Mars by Gaia.Comment: 4 pages, 3 figures, based on a talk presented at the Gaia-FUN-SSO-2
International Workshop, Paris Observatory, 19-21 September 2012. Part of the
proceedings of that worksho
Gaussian approximation and single-spin measurement in OSCAR MRFM with spin noise
A promising technique for measuring single electron spins is magnetic
resonance force microscopy (MRFM), in which a microcantilever with a permanent
magnetic tip is resonantly driven by a single oscillating spin. If the quality
factor of the cantilever is high enough, this signal will be amplified over
time to the point that it can be detected by optical or other techniques. An
important requirement, however, is that this measurement process occur on a
time scale short compared to any noise which disturbs the orientation of the
measured spin. We describe a model of spin noise for the MRFM system, and show
how this noise is transformed to become time-dependent in going to the usual
rotating frame. We simplify the description of the cantilever-spin system by
approximating the cantilever wavefunction as a Gaussian wavepacket, and show
that the resulting approximation closely matches the full quantum behavior. We
then examine the problem of detecting the signal for a cantilever with thermal
noise and spin with spin noise, deriving a condition for this to be a useful
measurement.Comment: 12 pages, 8 figures in EPS format, RevTeX 4.
Cell Division: Righting the Check
SummaryStudies in fission and budding yeast have continuously led the way for analyzing pathways of cell division. Two elegant studies, one from each yeast species, are opening the gates to study one of the final steps of mitosis â silencing the spindle checkpoint
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