13,982 research outputs found
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
Neutron-Rich Nuclei in Heaven and Earth
An accurately calibrated relativistic parametrization is introduced to
compute the ground state properties of finite nuclei, their linear response,
and the structure of neutron stars. While similar in spirit to the successful
NL3 parameter set, it produces an equation of state that is considerably softer
-- both for symmetric nuclear matter and for the symmetry energy. This
softening appears to be required for an accurate description of several
collective modes having different neutron-to-proton ratios. Among the
predictions of this model are a symmetric nuclear-matter incompressibility of
K=230 MeV and a neutron skin thickness in 208Pb of Rn-Rp=0.21 fm. Further, the
impact of such a softening on the properties of neutron stars is as follows:
the model predicts a limiting neutron star mass of Mmax=1.72 Msun, a radius of
R=12.66 km for a ``canonical'' M=1.4 Msun neutron star, and no (nucleon) direct
Urca cooling in neutrons stars with masses below M=1.3 Msun.Comment: 4 pages, 3 tables, and no figure
Boundary Dissipation in a Driven Hard Disk System
A simulation is performed aiming at checking the existence of a well defined
stationary state for a two dimensional system of driven hard disks when energy
dissipation takes place at the system boundaries and no bulk impurities are
presentComment: 5 pages, 7 figure
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
Farmer-Directed On-Farm Experimentation Examining the Impact of Companion Planting Barley and Oats on Timothy-Lucerne Forage Establishment in Central Newfoundland
Growing barley or oats in the year of forage establishment is a common agronomic practice in marginal growing regions, but is often not recommended to growers in Newfoundland. Spaner & Todd (2003) reported that barley seeded at rates of 100-150 kg seed/ha and undersown with a timothy-clover mixture (harvested at mid-milk) resulted in the planting year in greater forage yield of poorer quality than pure-stand timothy-clover. A barley seeding rate of 100 kg seed/ha did not impede forage production in the subsequent year
Biodiesel Mandate Laws in Argentina and Brazil: An Estimation of Soybean Oil Foregone Export Revenues
Replaced with revised version of paper 02/22/08.Research and Development/Tech Change/Emerging Technologies,
Minority and Women Entrepreneurs Contracting with thw Federal Government
 This article uses learning network theory as a foundation upon which the assistance and barriers minority and women entrepreneurs face when attempting to contract with the federal government may be studied. The public policy programs analyzed for this study were the SBA's 8(a) program and the Department of Defense's Procurement Technical Assistance Program (PTAC). The methodology utilized was an in-depth analysis of government contracting experiences in two states, Missouri and Kansas, in the greater Kansas City area via formalized interviews and government data. Research results revealed strong responses to the 8(a) program and its overall effectiveness. Racial issues were of a particular concern, as well as the perceived lack of strength behind 8(a) contracting incentives. The PTAC program was revealed to be reaching a significantly increasing percentage of woman owned businesses, and to a lesser extent, minority-owned businesses while providing a more effective learning strategy for gaining government contracts.
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