Thermophysical Characterization of Potential Spacecraft Target (101955) 1999 RQ36

We report on thermal emission measurements of 1999 RQ36 from Spitzer. The derived size is in agreement with radar measurements, and we find a moderately high thermal inertia and homogeneous surface properties

Nuclear Spectra of Comet 28P Neujmin 1

We present visible and near-IR spectra of the nucleus of comet 162P/Siding Spring (also known as 2004 TU12) obtained in 2004 December, while it had no detectable coma. This is the third object observed to have intermittent cometary activity even when relatively close to the Sun. The spectra show no strong features in this wavelength range. This paucity of deep absorptions is common among low-albedo asteroids and the few comet nuclei observed in this spectral region. Marginal spectral structure is observed in the visible spectrum, and beyond 2 μm the flux from the nucleus is dominated by thermal emission. We compare the spectrum of 162P with published spectra of other comet nuclei, primitive asteroids, and meteorites. Comet nuclei display a range of spectral shapes and slopes not unlike those observed among outer main-belt asteroids but closest to Trojan asteroids. No suitable spectral matches to comet 162P were found among primitive (chondritic) meteorites. We modeled our visible and near-IR spectra using the scattering theory described by Shkuratov et al. (1999), and our approach is similar to that used by Emery and Brown for modeling Trojan asteroids. Our best fits to the spectral shape and albedo include mixtures containing amorphous carbons, organics, and silicates. The absence of strong spectral features prevents the identification of specific minerals, and the resulting model compositions are not unique. The observations beyond 2 μm are interpreted in a companion publication by Fernández and coworkers

Nuclear Spectra of Comet 162P/Siding Spring (2004 TU12)

We present visible and near-IR spectra of the nucleus of comet 162P/Siding Spring (also known as 2004 TU12) obtained in 2004 December, while it had no detectable coma. This is the third object observed to have intermittent cometary activity even when relatively close to the Sun. The spectra show no strong features in this wavelength range. This paucity of deep absorptions is common among low-albedo asteroids and the few comet nuclei observed in this spectral region. Marginal spectral structure is observed in the visible spectrum, and beyond 2 μm the flux from the nucleus is dominated by thermal emission. We compare the spectrum of 162P with published spectra of other comet nuclei, primitive asteroids, and meteorites. Comet nuclei display a range of spectral shapes and slopes not unlike those observed among outer main-belt asteroids but closest to Trojan asteroids. No suitable spectral matches to comet 162P were found among primitive (chondritic) meteorites. We modeled our visible and near-IR spectra using the scattering theory described by Shkuratov et al. (1999), and our approach is similar to that used by Emery and Brown for modeling Trojan asteroids. Our best fits to the spectral shape and albedo include mixtures containing amorphous carbons, organics, and silicates. The absence of strong spectral features prevents the identification of specific minerals, and the resulting model compositions are not unique. The observations beyond 2 μm are interpreted in a companion publication by Fernández and coworkers

Day-ahead industrial load forecasting for electric RTG cranes

Given the increase in international trading and the significant energy and environmental challenges in ports around the world, there is a need for a greater understanding of the energy demand behaviour at ports. The move towards electrified rubber-tyred gantry (RTG) cranes is expected to reduce gas emissions and increase energy savings compared to diesel RTG cranes but it will increase electrical energy demand. Electrical load forecasting is a key tool for understanding the energy demand which is usually applied to data with strong regularities and seasonal patterns. However, the highly volatile and stochastic behaviour of the RTG crane demand creates a substantial prediction challenge. This paper is one of the first extensive investigations into short term load forecasts for electrified RTG crane demand. Options for model inputs are investigated depending on extensive data and correlation analysis. The effect of estimation accuracy of exogenous variables on the forecast accuracy is investigated as well. The models are tested on two different RTG crane data sets that were collected from the Port of Felixstowe in the UK. The results reveal the effectiveness of the forecast models when the estimation of the number of crane moves and container gross weight are accurate

Spatial heterogeneity of habitat suitability for Rift Valley fever occurrence in Tanzania: an ecological niche modelling approach

Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo