Bernard Yarnton Mills 1920-2011

Bernie Mills is remembered globally as an influential pioneer in the evolving field of radio astronomy. His contributions with the 'Mills Cross' at the CSIRO Division of Radiophysics and later at the University of Sydney's School of Physics and the development of the Molonglo Observatory Synthesis Telescope (MOST) were widely recognised as astronomy evolved in the years 1948-1985 and radio astronomy changed the viewpoint of the astronomer as a host of new objects were discovered

ANOMALOUS GAUGE BOSON INTERACTIONS

We discuss the direct measurement of the trilinear vector boson couplings in present and future collider experiments. The major goals of such experiments will be the confirmation of the Standard Model (SM) predictions and the search for signals of new physics. We review our current theoretical understanding of anomalous trilinear gauge boson self-interactions. If the energy scale of the new physics is $\sim 1$ TeV, these low energy anomalous couplings are expected to be no larger than ${\cal O}(10^{-2})$. Constraints from high precision measurements at LEP and low energy charged and neutral current processes are critically reviewed.Comment: 53 pages with 17 embedded figures, LaTeX, uses axodraw.sty, figures available on request. The complete paper, is available at ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z or http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z Summary of the DPF Working Subgroup on Anomalous Gauge Boson Interactions of the DPF Long Range Planning Stud

Modus Vivendi Beyond the Social Contract: Peace, Justice, and Survival in Realist Political Theory

This essay examines the promise of the notion of modus vivendi for realist political theory. I interpret recent theories of modus vivendi as affirming the priority of peace over justice, and explore several ways of making sense of this idea. I proceed to identify two key problems for modus vivendi theory, so conceived. Normatively speaking, it remains unclear how this approach can sustain a realist critique of Rawlsian theorizing about justice while avoiding a Hobbesian endorsement of absolutism. And conceptually, the theory remains wedded to a key feature of social contract theory: political order is conceived as based on agreement. This construes the horizontal tensions among individual or group agents in society as prior to the vertical, authoritative relations between authorities and their subjects. Political authority thereby appears from the start as a solution to societal conflict, rather than a problem in itself. I argue that this way of framing the issue abstracts from political experience. Instead I attempt to rethink the notion of modus vivendi from within the lived experience of political conflict, as oriented not primarily toward peace, but political survival. With this shift of perspective, the idea of modus vivendi shows us, pace Bernard Williams, that the “first political question” is not how to achieve order and stability, but rather: what can I live with

Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry

We present transport measurements of a tunable silicon metal-oxide-semiconductor double quantum dot device with lateral geometry. Experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. Comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.Comment: 4 pages, 3 figures, to be published in Applied Physics Letter

Klassifizierung von Siedlungsschichten an Sedimenten aus Bohrungen in archäologischen Denkmälern am Beispiel der wikingerzeitlichen Siedlung Haithabu

Ablagerungen in ehemaligen Siedlungen sind ein wichtiges Archiv zur Rekonstruktion von Mensch-Landschafts-Interaktionen. Bedeutende archäologische Befunde sind oft Denkmäler, die vor starken Eingriffen rechtlich geschützt sind. Haithabu, als ein wikingerzeitliches Handelszentrum und eine der ersten urbanen Siedlungen Nordeuropas, steht unter archäologischem Denkmalschutz. Daher werden Felduntersuchungen hier auf minimal-invasive Methoden, wie Bohrungen, eingeschränkt. Aus Bohrungen resultieren jedoch nur Punktinformationen, die eine Klassifizierung von Siedlungsschichten und das Verständnis ihrer räumlichen Zusammenhänge erschweren. Um die lokale Landschaftsentwicklung Haithabus zu untersuchen, wurden mehrere Hundert Bohrungen durchgeführt. Die Bohrkerne enthielten häufig Schichten, die morphologisch nicht eindeutig zu anthropogenen oder natürlichen Sedimenten zugeordnet werden konnten. Um solche Sedimente zu klassifizieren, wurde das Material von 8 Bohrkernen geochemisch untersucht. Die Parameter magnetische Suszeptibilität, Gehalt an organischer Substanz, Anteil an Steinen, Knochen, Artefakten und Holzresten wurden für statistische Analysen ausgewählt und dienten als Basis für die Klassifikation. Zur Bestimmung der Faktoren der Datenvarianz wurde eine Hauptkomponentenanalyse verwendet. Drei Hauptkomponenten, die 75,6 % der Varianz erklärten und ein Eigenwert > 1 hatten, wurden für die hierarchische Clusteranalyse benutzt. Die Clusteranalyse hat 15 Cluster ergeben, die signifikante Unterschiede in mindestens einem Parameter haben. Auf Basis dieser Ergebnisse wurden drei Sedimenttypen ermittelt, die insgesamt 12 Sedimentklassen aufweisen. Der erste Sedimenttyp enthält begrabene Bodenhorizonte und natürliche Ablagerungen, unter denen sich feines und grobes mineralisches Material sowie Torf befinden. Der zweite Sedimenttyp besitzt Übergangseigenschaften mit geringen Mengen an Holzresten und Knochen. Der dritte Typ besteht aus Schichten verschiedener Textur und variierenden Inhalts an organischem Material, die durch hohe Werte anthropogener Indikatoren (Artefakte und magnetische Suszeptibilität) gekennzeichnet sind. Sedimenttypen 2 und 3 enthalten sowohl Kolluvien als auch in situ Siedlungsschichten. Dieser Ansatz hat es ermöglicht, heterogene Ablagerungen Haithabus basierend auf objektiven und einfach messbaren Parametern zu klassifizieren. Er kann für geoarchäologische Forschungen in Siedlungen mit begrenztem Zugang durch Ausgrabungen angewandt werden

The Cyborg Astrobiologist: Testing a Novelty-Detection Algorithm on Two Mobile Exploration Systems at Rivas Vaciamadrid in Spain and at the Mars Desert Research Station in Utah

(ABRIDGED) In previous work, two platforms have been developed for testing computer-vision algorithms for robotic planetary exploration (McGuire et al. 2004b,2005; Bartolo et al. 2007). The wearable-computer platform has been tested at geological and astrobiological field sites in Spain (Rivas Vaciamadrid and Riba de Santiuste), and the phone-camera has been tested at a geological field site in Malta. In this work, we (i) apply a Hopfield neural-network algorithm for novelty detection based upon color, (ii) integrate a field-capable digital microscope on the wearable computer platform, (iii) test this novelty detection with the digital microscope at Rivas Vaciamadrid, (iv) develop a Bluetooth communication mode for the phone-camera platform, in order to allow access to a mobile processing computer at the field sites, and (v) test the novelty detection on the Bluetooth-enabled phone-camera connected to a netbook computer at the Mars Desert Research Station in Utah. This systems engineering and field testing have together allowed us to develop a real-time computer-vision system that is capable, for example, of identifying lichens as novel within a series of images acquired in semi-arid desert environments. We acquired sequences of images of geologic outcrops in Utah and Spain consisting of various rock types and colors to test this algorithm. The algorithm robustly recognized previously-observed units by their color, while requiring only a single image or a few images to learn colors as familiar, demonstrating its fast learning capability.Comment: 28 pages, 12 figures, accepted for publication in the International Journal of Astrobiolog

Decay-assisted collinear resonance ionization spectroscopy: Application to neutron-deficient francium

This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment.Comment: Accepted for publication with Physical Review

Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry

The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $\delta\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This suggests that both isotopes reside at the borders of a region of inverted staggering, which has been associated with reflection-asymmetric shapes. The $g(^{219}\text{Fr}) = +0.69(1)$ value supports a $\pi 1h_{9/2}$ shell model configuration for the ground state. The $g(^{229,231}\text{Fr})$ values support the tentative $I^{\pi}(^{229,231}\text{Fr}) = (1/2^{+})$ spin, and point to a $\pi s_{1/2}^{-1}$ intruder ground state configuration.Comment: Accepted for publication with Physical Review