89 research outputs found

    ArMedEa project : archaeology of medieval earthquakes in Europe (1000-1550 AD). First research activities.

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    This paper introduces the research of the Armedea project. Armedea (Archaeology of medieval earthquakes in Europe, 1000-1550 AD) is a medieval archaeology project undertaken at the Department of Archaeology of Durham University which analyses archaeological evidence related to late medieval seismic-affected contexts at a European scale. This project is therefore focused on both earthquake effects on archaeological sites, their standing buildings and environment, and the archaeological evidence that reveals the response of medieval societies in terms of risk reduction, protection and resilience. A first preview of GIS analysis of seismic activity impact on medieval societies and fieldwork activities carried out in Italy, Cyprus and Azores (Portugal) is presented here. This research is supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme

    The role of graphite layers in gravitational deformation of pelitic schist

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    Deep-seated landslides in pelitic schists are common in many countries, but are poorly investigated and understood. In this study we present the first detailed examination and modelling of landslide mechanisms in these materials. We found that pelitic schist commonly contains black, graphite-rich layers on a scale of millimeters to centimeters thickness that are typically weaker than neighboring layers. By examining microscopic textures in borehole samples obtained from landslide masses of pelitic schist, we find that ductile gravitational shearing commonly occurs within these weaker layers, accompanied by brittle fracture in the surrounding layers. To investigate this mechanisms, we have performed high-precision direct shear tests, using a novel back-pressured shearbox, on artificial rock samples both with and without graphite layers placed between pre-cut shear surfaces. The tests used normal stresses up to 800 kPa (equivalent to 32 m depth of burial). We found that the coefficients of friction for samples with graphite layers embedded in the artificial rock samples (0.30, representing an angle of internal friction of 16.7°) were much lower than those without graphite layers on the pre-cut surface (0.85). The shear strength of the artificial rocks with embedded layers of graphite decreased abruptly with increasing areal extent of the graphite layer along the shear surface, from which it can be inferred that the continuity of a graphite layer in natural pelitic schist has a considerable effect on shear resistance. These results suggest that even comparatively low dip angles of schistosity in pelitic schist could initiate microscopic slip along the graphite-rich layers

    The idea of moral panic – ten dimensions of dispute

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    This paper explores the open and contested concept of moral panic over its 40-year history, exploring the contributions made by the concept’s key originators, as well as contemporary researchers. While most moral panic researchers are critical, humanist, interpretivist, interventionist and qualitative, this paper highlights ten areas of productive dispute within and around the meaning of moral panic theory’s ‘common sense’. Such diversity of interpretation creates multiple possibilities for convergent and divergent theorization and research within a supposedly singular conceptual framework. This lack of closure and consequent diversity of political standpoints, intellectual perspectives and fields of empirical focus, rather than representing the weakness of the concept of moral panic, reflects and contributes to its successful diffusion, escalation and innovation

    Understanding fatal landslides at global scales:a summary of topographic, climatic, and anthropogenic perspectives

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    Landslides are a common global geohazard that lead to substantial loss of life and socio-economic damage. Landslides are becoming more common due to extreme weather events and the impacts of anthropogenic disturbance, and thus, they are threatening sustainable development in many vulnerable areas. Previous studies on fatal landslides have focused on inventory development; spatial and temporal distributions; the role of precipitation or seismic forcing; and human impacts. However, climatologic, topographic, and anthropogenic variables featuring fatal landslides at a global scale have been mostly neglected. Here, using the global fatal landslide database, we evaluate the characteristics of landslides induced by natural and anthropogenic factors with respect to topographic, climatic, and anthropogenic factors, drawing attention to their persistent spatial patterns. The majority of natural (69.3%) and anthropogenic (44.1%) landslides occur in mountainous areas in tropical and temperate regions, which are also characterized by the highest casualty rates per group, 66.7% and 43.0%, respectively. However, they significantly differ in terms of their morphometric footprint. Fatal landslides triggered by natural variables occur mostly in the highest portions of the topographic profile, where human disturbance is minimal. As for their anthropogenic counterpart, these failures cluster at much lower altitudes, where slopes are gentler, but human intervention is higher due to a higher population density. This observation points towards land cover changes being a critical factor in landscape dynamics, stressing the human pressure as a discriminant cause/effect term for natural vs. human-induced landslide fatalities.</p

    Patterns of precursory rockfall prior to slope failure

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    In this paper we examine data generated using high-resolution three-dimensional laser scanning monitoring of coastal rock cliffs. These data are used to identify spatial and temporal patterns in rockfall activity behavior prior to slope failure. Analysis of the data suggests that given sufficient measurement precision precursory behavior, here manifest as the rate of rockfall activity prior to failure, can be detected, measured, and monitored. Environmental conditions appear to have a diminishing influence on the occurrence of increasingly large slope failures. The monitoring data implies a time-dependent sequence in the occurrence of smaller rockfalls in the period leading to the largest failures recorded. This behavior is attributed to the mechanisms of strain accumulation in the rock mass resulting from brittle failure of the slope. The implication is that combining these data with models of failure mechanisms may allow failure time to be forecast from wide-area monitoring of precursory behavior. These findings have implications for the management of potentially unstable slopes, the understanding of slope failure mechanisms, and the generation of a new type of slope failure warning systems

    Television news and the symbolic criminalisation of young people

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    This is an Author's Accepted Manuscript of an article published in Journalism Studies, 9(1), 75 - 90, 2008, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/14616700701768105.This essay combines quantitative and qualitative analysis of six UK television news programmes. It seeks to analyse the representation of young people within broadcast news provision at a time when media representations, political discourse and policy making generally appear to be invoking young people as something of a folk devil or a locus for moral panics. The quantitative analysis examines the frequency with which young people appear as main actors across a range of different subjects and analyses the role of young people as news sources. It finds a strong correlation between young people and violent crime. A qualitative analysis of four “special reports” or backgrounders on channel Five's Five News explores the representation of young people in more detail, paying attention to contradictions and tensions in the reports, the role of statistics in crime reporting, the role of victims of crime and the tensions between conflicting news frames.Arts and Humanities Research Counci

    Investigating the influence of the jet from three nozzle and spear design configurations on Pelton runner performance by numerical simulation

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    This paper reports the initial results of three dimensional CFD simulations of the jet – runner interactions in a twin jet horizontal axis Pelton turbine. More specifically, the analysis examines the impact of the nozzle and spear valve configuration on the performance of the runner. Previous research has identified that injectors with notably steeper nozzle and spear angles attain a higher efficiency than the industry standard. However, experimental testing of the entire Pelton system suggests that there appears to be an upper limit beyond which steeper angled designs are no longer optimal. In order to investigate the apparent difference between the numerical prediction of efficiency for the injector system and the obtained experimental results, four different jet configurations are analysed and compared. In the first configuration, the interaction between the runner and an ideal axisymmetric jet profile is investigated. In the final three configurations the runner has been coupled with the jet profile from the aforementioned injectors, namely the Standard design with nozzle and spear angles of 80° & 55° and two Novel designs with angles 110° & 70° and 150° & 90° respectively. The results are compared by examining the impact the jet shape has on the runner torque profile during the bucket cycle and the influence this has on turbine efficiency. All results provided incorporate the Reynolds averaged Navier Stokes (RANS) Shear Stress Transport (SST) turbulence model and a two-phase Volume of Fluid (VOF) model, using the ANSYS¼ FLUENT¼ code. Therefore, this paper offers new insights into the optimal jet – runner interaction

    How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?

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    The origin of radio emission in different populations of radio-quiet quasars is relatively unknown, but recent work has uncovered various drivers of increased radio-detection fraction. In this work, we pull together three known factors: optical colour (g - i), C IV distance (a proxy for L/LEdd), and whether or not the quasar contains broad absorption lines (BALQSOs) which signify an outflow. We use SDSS (Sloan Digital Sky Survey) DR14 spectra along with the LOFAR Two Metre Sky Survey Data Release 2 and find that each of these properties have an independent effect. BALQSOs are marginally more likely to be radio-detected than non-BALQSOs at similar colours and L/LEdd, moderate reddening significantly increases the radio-detection fraction and the radio detection increases with L/LEdd above a threshold for all populations. We test a widely used simple model for radio wind shock emission and calculate energetic efficiencies that would be required to reproduce the observed radio properties. We discuss interpretations of these results concerning radio-quiet quasars more generally. We suggest that radio emission in BALQSOs is connected to a different physical origin than the general quasar population since they show different radio properties independent of colour and C IV distance

    A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems

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    To understand the active galactic nuclei (AGNs) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive multiwavelength data in the COSMOS field to select a complete sample of 578 infrared (IR) quasars (LAGN,IR > 1045 erg s−1) at z < 3, with minimal obscuration bias, using detailed UV-to-far-IR spectral energy distribution (SED) fitting. We complement our SED constraints with X-ray and radio observations to further investigate the properties of the sample. Overall, 322 of the IR quasars are detected by Chandra and have individual X-ray spectral constraints. From a combination of X-ray stacking and L2−10 kev – L6 ÎŒm analyses, we show that the majority of the X-ray faint and undetected quasars are heavily obscured (many are likely Compton thick), highlighting the effectiveness of the mid-IR band to find obscured AGNs. We find that 355 (≈61 per cent) IR quasars are obscured (NH > 1022 cm−2) and identify differences in the average properties between the obscured and unobscured quasars: (1) obscured quasars have star formation rates ≈3 times higher than unobscured systems for no significant difference in stellar mass and (2) obscured quasars have stronger radio emission than unobscured systems, with a radio-loudness parameter ≈ 0.2 dex higher. These results are inconsistent with a simple orientation model but in general agreement with either extreme host-galaxy obscuration towards the obscured quasars or a scenario where obscured quasars are an early phase in the evolution of quasars

    'It's a film' : medium specificity as textual gesture in Red road and The unloved

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    British cinema has long been intertwined with television. The buzzwords of the transition to digital media, 'convergence' and 'multi-platform delivery', have particular histories in the British context which can be grasped only through an understanding of the cultural, historical and institutional peculiarities of the British film and television industries. Central to this understanding must be two comparisons: first, the relative stability of television in the duopoly period (at its core, the licence-funded BBC) in contrast to the repeated boom and bust of the many different financial/industrial combinations which have comprised the film industry; and second, the cultural and historical connotations of 'film' and 'television'. All readers of this journal will be familiar – possibly over-familiar – with the notion that 'British cinema is alive and well and living on television'. At the end of the first decade of the twenty-first century, when 'the end of medium specificity' is much trumpeted, it might be useful to return to the historical imbrication of British film and television, to explore both the possibility that medium specificity may be more nationally specific than much contemporary theorisation suggests, and to consider some of the relationships between film and television manifest at a textual level in two recent films, Red Road (2006) and The Unloved (2009)
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