CO adsorption on (111) and (100) surfaces of the Pt sub 3 Ti alloy. Evidence for parallel binding and strong activation of CO

The CO adsorption on a 40 atom cluster model of the (111) surface and a 36 atom cluster model of the (100) surface of the Pt3Ti alloy was studied. Parallel binding to high coordinate sites associated with Ti and low CO bond scission barriers are predicted for both surfaces. The binding of CO to Pt sites occurs in an upright orientation. These orientations are a consequence of the nature of the CO pi donation interactions with the surface. On the Ti sites the orbitals donate to the nearly empty Ti 3d band and the antibonding counterpart orbitals are empty. On the Pt sites, however, they are in the filled Pt 5d region of the alloy band, which causes CO to bond in a vertical orientation by 5 delta donation from the carbon end

The Evolution of Post-Starburst Galaxies from z∼1z\sim1 to the Present

Post-starburst galaxies are in the transitional stage between blue, star-forming galaxies and red, quiescent galaxies, and therefore hold important clues for our understanding of galaxy evolution. In this paper, we systematically searched for and identified a large sample of post-starburst galaxies from the spectroscopic dataset of the Sloan Digital Sky Survey (SDSS) Data Release 9. In total, we found more than 6000 objects with redshifts between $z\sim0.05$ and $z\sim1.3$, making this the largest sample of post-starburst galaxies in the literature. We calculated the luminosity function of the post-starburst galaxies using two uniformly selected subsamples: the SDSS Main Galaxy Sample and the Baryon Oscillation Spectroscopic Survey CMASS Sample. The luminosity functions are reasonably fit by half-Gaussian functions. The peak magnitudes shift as a function of redshift from $M\sim-23.5$ at $z\sim0.8$ to $M\sim-20.3$ at $z\sim0.1$. This is consistent with the downsizing trend, whereby more massive galaxies form earlier than low-mass galaxies. We compared the mass of the post-starburst stellar population found in our sample to the decline of the global star-formation rate and found that only a small amount ($\sim1\%$) of all star-formation quenching in the redshift range $z=0.2-0.7$ results in post-starburst galaxies in the luminosity range our sample is sensitive to. Therefore, luminous post-starburst galaxies are not the place where most of the decline in star-formation rate of the universe is happening.Comment: 26 pages, 24 figures, 8 tables. Accepted for publication in The Astrophysical Journa

Bringing self assessment home: repository profiling and key lines of enquiry within DRAMBORA

Digital repositories are a manifestation of complex organizational, financial, legal, technological, procedural, and political interrelationships. Accompanying each of these are innate uncertainties, exacerbated by the relative immaturity of understanding prevalent within the digital preservation domain. Recent efforts have sought to identify core characteristics that must be demonstrable by successful digital repositories, expressed in the form of check-list documents, intended to support the processes of repository accreditation and certification. In isolation though, the available guidelines lack practical applicability; confusion over evidential requirements and difficulties associated with the diversity that exists among repositories (in terms of mandate, available resources, supported content and legal context) are particularly problematic. A gap exists between the available criteria and the ways and extent to which conformity can be demonstrated. The Digital Repository Audit Method Based on Risk Assessment (DRAMBORA) is a methodology for undertaking repository self assessment, developed jointly by the Digital Curation Centre (DCC) and DigitalPreservationEurope (DPE). DRAMBORA requires repositories to expose their organization, policies and infrastructures to rigorous scrutiny through a series of highly structured exercises, enabling them to build a comprehensive registry of their most pertinent risks, arranged into a structure that facilitates effective management. It draws on experiences accumulated throughout 18 evaluative pilot assessments undertaken in an internationally diverse selection of repositories, digital libraries and data centres (including institutions and services such as the UK National Digital Archive of Datasets, the National Archives of Scotland, Gallica at the National Library of France and the CERN Document Server). Other organizations, such as the British Library, have been using sections of DRAMBORA within their own risk assessment procedures. Despite the attractive benefits of a bottom up approach, there are implicit challenges posed by neglecting a more objective perspective. Following a sustained period of pilot audits undertaken by DPE, DCC and the DELOS Digital Preservation Cluster aimed at evaluating DRAMBORA, it was stated that had respective project members not been present to facilitate each assessment, and contribute their objective, external perspectives, the results may have been less useful. Consequently, DRAMBORA has developed in a number of ways, to enable knowledge transfer from the responses of comparable repositories, and incorporate more opportunities for structured question sets, or key lines of enquiry, that provoke more comprehensive awareness of the applicability of particular threats and opportunities

FUSULINID SEQUENCE EVOLUTION AND SEQUENCE EXTINCTIONIN WOLFCAMPIAN AND LEONARDIAN SERIES (LOWER PERMIAN),GLASS MOUNTAINS, WEST TEXAS

In the Permian Wolfcampian and Leonardian Series of West Texas, sequence evolution and sequence extinction record the appearance and disappearance of morphological species in stratigraphic successions that show repeated sea level fluctuations and associated depositional hiatuses. The lower Wolfcampian Nealian Stage includes 16 relatively short term sea-level fluctuations (fourth-order depositional sequences) and contains a diverse fusulinid fauna of more than 39 species and eight genera.  Most Nealian species range through three or four fourth-order cycles before becoming extinct and none extends into the overlying upper Wolfcampian Lenoxian Stage.  The succeeding Lenox Hills Formation overlies a tectonic unconformity (and hiatus) and includes three third-order depositional sequences.  Four Lenoxian species are restricted to the lower sequence, 16 to the middle sequence, and six to the upper sequence. In the Leonardian Series, at the base, the Hessian Stage includes seven third-order depositional sequences and numerous minor fourth-order and smaller parasequences.  Hessian carbonate platform facies have low fusulinid species diversity and high abundances.  The lower four Hessian lowstand clastic wedges of the shelf margin and basin include at least six species of schwagerinids.  The three upper wedges include only three species of Parafusulina. The Cathedralian (upper) Stage has one main third-order depositional sequence, and perhaps a second, which is mostly missing on the platform below the Mid-Permian unconformity below the Middle Permian Guadalupian Series. Suggested correlations of the Wolfcampian and Leonardian with the Tethyan succession in Darvas and the Pamirs of Middle Asia place the Nealian as equivalent to the Asselian and Sakmarian. The Lenoxian is probably equivalent to the lower and middle parts of the Yakhtashian.  The Hessian is equivalent to the upper part of the Yakhtashian and the Bolorian. The Cathedralian seems to be equivalent to the Kubergandian. There is little evidence that the upper part of the Kubergandian extends higher into the Middle Permian Roadian Stage.&nbsp

Biostratigraphic Zonation of Late Paleozoic Depositional Sequences

Correlation of more than seventy third-order depositional sequences in Carboniferous and Permian strata uses assemblage zones of warm water benthic and nektonic shelf faunas. These include calcareous foraminifers, bryozoans, conodonts, and ammonoids and represent tropical, subtropical, and warm temperate water faunas from carbonate shelves and adjacent cratonic basins. After the Early Carboniferous faunal zonation was highly provincial and worldwide correlations of depositional sequences are based on interpretations of evolutionary lineages and depositional patterns in each province and in identifying times of limited dispersals between provinces. Associated with these faunal zones there were times of expanded or reduced faunal diversities and temperature related latitudinal expansion or reduction of faunas. Higher sea levels during warmer times enhanced faunal evolution and diversity and lower sea levels during cooler times dampened evolution and diversity and resulted in many species becoming extinct. After the Early Carboniferous, provincial faunal zonations and evolutionary lineages developed as a consequence of the formation of Lesser Pangaea. Further isolation of these provinces resulted in faunal realms in the middle Early Permian after the formation of Greater Pangaea

Getting to know you: Accuracy and error in judgments of character

Character judgments play an important role in our everyday lives. However, decades of empirical research on trait attribution suggest that the cognitive processes that generate these judgments are prone to a number of biases and cognitive distortions. This gives rise to a skeptical worry about the epistemic foundations of everyday characterological beliefs that has deeply disturbing and alienating consequences. In this paper, I argue that this skeptical worry is misplaced: under the appropriate informational conditions, our everyday character-trait judgments are in fact quite trustworthy. I then propose a mindreading-based model of the socio-cognitive processes underlying trait attribution that explains both why these judgments are initially unreliable, and how they eventually become more accurate

Customer premise service study for 30/20 GHz satellite system

Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band