Astrometric orbits of SB9 stars

Hipparcos Intermediate Astrometric Data (IAD) have been used to derive astrometric orbital elements for spectroscopic binaries from the newly released Ninth Catalogue of Spectroscopic Binary Orbits (SB9). Among the 1374 binaries from SB9 which have an HIP entry, 282 have detectable orbital astrometric motion (at the 5% significance level). Among those, only 70 have astrometric orbital elements that are reliably determined (according to specific statistical tests discussed in the paper), and for the first time for 20 systems, representing a 10% increase relative to the 235 DMSA/O systems already present in the Hipparcos Double and Multiple Systems Annex. The detection of the astrometric orbital motion when the Hipparcos IAD are supplemented by the spectroscopic orbital elements is close to 100% for binaries with only one visible component, provided that the period is in the 50 - 1000 d range and the parallax is larger than 5 mas. This result is an interesting testbed to guide the choice of algorithms and statistical tests to be used in the search for astrometric binaries during the forthcoming ESA Gaia mission. Finally, orbital inclinations provided by the present analysis have been used to derive several astrophysical quantities. For instance, 29 among the 70 systems with reliable astrometric orbital elements involve main sequence stars for which the companion mass could be derived. Some interesting conclusions may be drawn from this new set of stellar masses, like the enigmatic nature of the companion to the Hyades F dwarf HIP 20935. This system has a mass ratio of 0.98 but the companion remains elusive.Comment: Astronomy & Astrophysics, in press (16 pages, 12 figures); also available at http://www.astro.ulb.ac.be/Html/ps.html#Astrometr

88th Commencement Class Speaker\u27s Address

Kristin Griffin tells the soon-to-be-graduates, We are so fortunate to have built up this kind of support for ourselves as we face something we can’t quite see, and those who make that possible — our friends, our professors, our families — should know today that they have made the difference in each of our lives

Energy Gap Contributes to Adolescent Obesity

Summarizes findings on the gap between the calories American children and adolescents consume and the calories needed for normal growth, physical activity, and body function. Compares the overall gap with that of overweight adolescents over ten years

Using geocaching as a teaching tool with student architects

Geocaching is a global positioning system (GPS) based treasure hunt game that is played throughout the world. Participants find hidden containers, called geocaches, using GPS coordinates and then share their experiences online. The inherent manipulability of the game enables those who choose to plant geocaches to introduce site-specific information, which can lead to a multitude of participant experiences, making the game a flexible and informative learning exercise. At the University of Huddersfield School of Art, Design and Architecture (SoADA), geocaching has been used for many years as a teaching tool allowing students to investigate a variety of places at a tangible level and analyse a site’s complexities in preparation for contextually responsive design projects. An important part of a student’s measurable outcome and reflection process in response to the geocaching exercise is the production of a Site Investigation Report. This resource captures a student’s experiential and emotional responses towards a place and forms an important briefing document for a conjoining subsequent contextual design project. An important pursuit that geocaching fosters is a site-specific design response with a sustainable emphasis. When the notion of sustainable architecture is stripped of all the measuring processes, (which in many cases have diluted the important concern for the well-being of our world and the people who live on it into a collection of detracting and often irrelevant details for the purposes of ‘easy measurement’), we find that what remains are beauty and appropriateness. Sustainable architecture is at its core, architecture that people want to sustain. The primary purpose for utilising geocaching as a teaching tool at SoADA is to further assist students to gain a deep understanding of context so as to produce site-specific sustainable design projects that people would want to keep

Rigorous Density Functional Theory for Inhomogeneous Bose-Condensed Fluids

The density functional theory originally developed by Hohenberg, Kohn and Sham provides a rigorous conceptual framework for dealing with inhomogeneous interacting Fermi systems. We extend this approach to deal with inhomogeneous interacting Bose-condensed systems, limiting this presentation to setting up the formalism to deal with ground state $(T=0)$ properties. The key new feature is that one must deal with energy functionals of both the local density $n({\bf r})$ and the local complex macroscopic wavefunction $\Phi ({\bf r})$ associated with the Bose broken-symmetry (the local condensate density is $n_{c}({\bf r}) = \vert \Phi ({\bf r}) \vert ^{2}$). Implementing the Kohn-Sham scheme, we reduce the problem to a gas of weakly-interacting Bosons moving in self-consistent diagonal and off-diagonal one-body potentials. Our formalism should provide the basis for studies of the surface properties of liquid $^4$He as well as the properties of Bose-condensed atomic gases trapped in external potentials.Comment: 20 page

Two Sides of a Sargasso Sea : Successive Prosecution for the Same Offence in the United States and the United Kingdom

This article analyzes the U. S. constitutional law interpreting the concept of “same offence.” Included is a survey of the Supreme Court\u27s attempts to interpret constitutional text in order to provide adequate protection for the underlying double jeopardy interest against vexatious reprosecutions, which have frequently produced inconsistent and illogical results. Part III of this article analyzes U.K. law relating to the concept of “same offence,” where the same narrow double jeopardy protection adopted by the U.S. Supreme Court is supplemented with a broad discretion to prevent unfair successive prosecution that constitutes an abuse of process. Part IV draws lessons from a comparison of U.S. and U.K. law that might serve to rationalize and clarify the U.S. Supreme Court\u27s jurisprudence by supplementing the narrow same-elements interpretation of the Double Jeopardy Clause with a due process or supervisory-power protection against oppressive multiple prosecutions