Adiabat_1ph: A new public front-end to the MELTS, pMELTS, and pHMELTS models

The program adiabat_1ph is a simple text-menu driver for subroutine versions of the algorithms MELTS, pMELTS, and pHMELTS [Asimow et al., 2004; Ghiorso et al., 2002; Ghiorso and Sack, 1995]. It may be used to calculate equilibrium assemblages along a thermodynamic path set by the user and can simultaneously calculate trace element distributions. The MELTS family of algorithms is suitable for multicomponent systems, which may be anhydrous, water-undersaturated, or water-saturated, with the options of buffering oxygen fugacity and/or water activity. A wide variety of calculations can be performed either subsolidus or with liquid(s) present; melting and crystallization may be batch, fractional, or continuous. The software is suitable for Linux, MacOS X, and Windows, and many aspects of program execution are controlled by environment variables. Perl scripts are also provided that may be used to invoke adiabat_1ph with some command line options and to produce output that may be easily imported into spreadsheet programs, such as Microsoft Excel. Benefits include a batch mode, which allows almost complete automation of the calculation process when suitable input files are written. This technical brief describes version 1.04, which is provided as ancillary material. Binaries, scripts, documentation, and example files for this and future releases may be downloaded at http://www.gps.caltech.edu/~asimow/adiabat. On a networked computer, adiabat_1ph automatically checks whether a newer version is available

Measuring eccentricity in binary black hole inspirals with gravitational waves

When binary black holes form in the field, it is expected that their orbits typically circularize before coalescence. In galactic nuclei and globular clusters, binary black holes can form dynamically. Recent results suggest that $\approx5\%$ of mergers in globular clusters result from three-body interactions. These three-body interactions are expected to induce significant orbital eccentricity $\gtrsim 0.1$ when they enter the Advanced LIGO band at a gravitational-wave frequency of 10 Hz. Measurements of binary black hole eccentricity therefore provide a means for determining whether or not dynamic formation is the primary channel for producing binary black hole mergers. We present a framework for performing Bayesian parameter estimation on gravitational-wave observations of black hole inspirals. Using this framework, and employing the non-spinning, inspiral-only EccentricFD waveform approximant, we determine the minimum detectable eccentricity for an event with masses and distance similar to GW150914. At design sensitivity, we find that the current generation of advanced observatories will be sensitive to orbital eccentricities of $\gtrsim0.05$ at a gravitational-wave frequency of 10 Hz, demonstrating that existing detectors can use eccentricity to distinguish between circular field binaries and globular cluster triples. We compare this result to eccentricity distributions predicted to result from three black hole binary formation channels, showing that measurements of eccentricity could be used to infer the population properties of binary black holes.Comment: 12 pages, 7 figures, 2 table

Intrusion Detection Systems for Community Wireless Mesh Networks

Wireless mesh networks are being increasingly used to provide affordable network connectivity to communities where wired deployment strategies are either not possible or are prohibitively expensive. Unfortunately, computer networks (including mesh networks) are frequently being exploited by increasingly profit-driven and insidious attackers, which can affect their utility for legitimate use. In response to this, a number of countermeasures have been developed, including intrusion detection systems that aim to detect anomalous behaviour caused by attacks. We present a set of socio-technical challenges associated with developing an intrusion detection system for a community wireless mesh network. The attack space on a mesh network is particularly large; we motivate the need for and describe the challenges of adopting an asset-driven approach to managing this space. Finally, we present an initial design of a modular architecture for intrusion detection, highlighting how it addresses the identified challenges

Placing the university: thinking in and beyond globalization

In some respects, the impact of globalization on universities is well rehearsed (competition for international students; the drive for status in global rankings; the opening of overseas campuses; the dream of massive open online courses and other forms of digital education), but the relationship between universities as place-based institutions and globalization is less well understood. It is on that this chapter focuses. Drawing on work undertaken as part of an Economic and Social Research Council project (“Higher Education and Regional Social Transformation”) the author sets the arguments in a wider context. He explores the extent to which and ways in which universities have become key players in the reimagination of their city regions in a (neoliberal) global context. As well as reflecting on the wider public (and local) role of universities, he also considers how universities use the tools available to them to position themselves effectively as successful businesses within the new world in which they find themselves

Nuevas aberraciones de plumaje en aves paraguayas no passeriformes y la definición de una nueva aberración de plumaje única a Psittacidae

Anomalous plumage colourations are reported for three species of non-passerine birds from Paraguay, Limpkin (Aramaus guarauna; Aramidae), Nanday Parakeet (Nandayus nenday; Psittacidae), and the Little Woodpecker (Veniliornis passerinus; Picidae). A leucistic Limpkin is the first published report of a colour anomaly for the family Aramidae. The colour aberration in N. nenday is hypothesised to be a result of an excess of red psittacofulvin pigments, which are unique to the Psittacidae. Although the mechanisms causing this colour aberration remain unknown, we suggest the term psittacofulvism for the phenotypic effect observed.Se reportan anomalías en la coloración de tres aves no passeriformes del Paraguay, caraú Aramus guarauna (Aramidae), ñanday Nandayus nenday (Psittacidae) y carpinterito oliváceo Veniliornis passerinus (Picidae). Un caraú leucístico es el primer reporte publicado de coloración anómala en Aramidae. La presencia de coloración aberrante en Nandayus se hipotetiza como resultado de un exceso de pigmentos psittacofulvinos rojos, únicos a los Psittacidae. Aunque el mecanismo causante de esta aberración de color sigue siendo desconocido, sugerimos el término psittacofulvismo para el efecto fenotípico observado

Molecular-dynamics simulation study of dielectric relaxation in a 1,4-polybutadiene melt

Journal ArticleWe have carried out atomistic molecular dynamics simulations of a melt of 1,4-poly(butadiene) from temperatures well above the experimentally observed merging of the primary a process and secondary b process down to temperatures approaching the experimentally observed bifurcation temperature. The relaxation strength and maximum loss frequency and its temperature dependence for the combined a-b dielectric relaxation process from simulations were in good agreement with experiment. The maximum loss frequency, melt viscosity, chain normal-mode relaxation times and torsional autocorrelation times were found to exhibit nearly identical non-Arrhenius temperature dependencies well represented by a Vogel-Fulcher fit with parameters in good agreement with experimental values obtained from dielectric and viscosity measurements