1,344 research outputs found

    Towards the “ultimate earthquake-proof” building: Development of an integrated low-damage system

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    The 2010–2011 Canterbury earthquake sequence has highlighted the severe mismatch between societal expectations over the reality of seismic performance of modern buildings. A paradigm shift in performance-based design criteria and objectives towards damage-control or low-damage design philosophy and technologies is urgently required. The increased awareness by the general public, tenants, building owners, territorial authorities as well as (re)insurers, of the severe socio-economic impacts of moderate-strong earthquakes in terms of damage/dollars/ downtime, has indeed stimulated and facilitated the wider acceptance and implementation of cost-efficient damage-control (or low-damage) technologies. The ‘bar’ has been raised significantly with the request to fast-track the development of what the wider general public would hope, and somehow expect, to live in, i.e. an “earthquake-proof” building system, capable of sustaining the shaking of a severe earthquake basically unscathed. The paper provides an overview of recent advances through extensive research, carried out at the University of Canterbury in the past decade towards the development of a low-damage building system as a whole, within an integrated performance-based framework, including the skeleton of the superstructure, the non-structural components and the interaction with the soil/foundation system. Examples of real on site-applications of such technology in New Zealand, using concrete, timber (engineered wood), steel or a combination of these materials, and featuring some of the latest innovative technical solutions developed in the laboratory are presented as examples of successful transfer of performance-based seismic design approach and advanced technology from theory to practice

    Using a prisoner advisory group to develop diversity research in a maximum-security prison

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    This paper addresses groupwork processes with a group of prisoners advising a research project in a maximum-security prison in England. The research project (Appreciative Inquiry into the Diversity Strategy of HMP Wakefield. RES-000-22-3441) was funded by the Economic and Social Research Council (ESRC) and lasted 9 months. The research explored the experiences of prisoners in diverse minority groupings and the strategies of the prison to accommodate the complex needs of these groups. The Prisoner Advisory Group (PAG) was made up of representatives from Black and Minority Ethnic (BME) prisoners; older prisoners (over 60s); Disabled prisoners (with physical disabilities, learning difficulties; and mental health problems); Gay, Bi-sexual and Transgender prisoners; and prisoners affiliated to Faith groups. It met regularly during the research. The paper considers the forming norming and performing aspects of establishing an effective participant voice in a prison-based project. It considers the contribution of the PAG to developing a research strategy that engaged prisoners in the research. It reflects on the nature of ‘participative research’ in general and whether such research is possible within a high-security prison environment

    NEATH II: N2_2H+^+ as a tracer of imminent star formation in quiescent high-density gas

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    Star formation activity in molecular clouds is often found to be correlated with the amount of material above a column density threshold of ∌1022 cm−2\sim 10^{22} \, {\rm cm^{-2}}. Attempts to connect this column density threshold to a volume{\it volume} density above which star formation can occur are limited by the fact that the volume density of gas is difficult to reliably measure from observations. We post-process hydrodynamical simulations of molecular clouds with a time-dependent chemical network, and investigate the connection between commonly-observed molecular species and star formation activity. We find that many molecules widely assumed to specifically trace the dense, star-forming component of molecular clouds (e.g. HCN, HCO+^+, CS) actually also exist in substantial quantities in material only transiently enhanced in density, which will eventually return to a more diffuse state without forming any stars. By contrast, N2_2H+^+ only exists in detectable quantities above a volume density of 104 cm−310^4 \, {\rm cm^{-3}}, the point at which CO, which reacts destructively with N2_2H+^+, begins to deplete out of the gas phase onto grain surfaces. This density threshold for detectable quantities of N2_2H+^+ corresponds very closely to the volume density at which gas becomes irreversibly gravitationally bound in the simulations: the material traced by N2_2H+^+ never reverts to lower densities, and quiescent regions of molecular clouds with visible N2_2H+^+ emission are destined to eventually form stars. The N2_2H+^+ line intensity is likely to directly correlate with the star formation rate averaged over timescales of around a Myr.Comment: 10 pages, 10 figures. MNRAS accepte

    Non-Equilibrium Abundances Treated Holistically (NEATH): the molecular composition of star-forming clouds

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    Much of what we know about molecular clouds, and by extension star formation, comes from molecular line observations. Interpreting these correctly requires knowledge of the underlying molecular abundances. Simulations of molecular clouds typically only model species that are important for the gas thermodynamics, which tend to be poor tracers of the denser material where stars form. We construct a framework for post-processing these simulations with a full time-dependent chemical network, allowing us to model the behaviour of observationally-important species not present in the reduced network used for the thermodynamics. We use this to investigate the chemical evolution of molecular gas under realistic physical conditions. We find that molecules can be divided into those which reach peak abundances at moderate densities (103 cm−310^3 \, {\rm cm^{-3}}) and decline sharply thereafter (such as CO and HCN), and those which peak at higher densities and then remain roughly constant (e.g. NH3_3, N2_2H+^+). Evolving the chemistry with physical properties held constant at their final values results in a significant overestimation of gas-phase abundances for all molecules, and does not capture the drastic variations in abundance caused by different evolutionary histories. The dynamical evolution of molecular gas cannot be neglected when modelling its chemistry.Comment: 14 pages, 13 figures. MNRAS accepte

    Swimming against the tide: A case study of an integrated social studies department

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    A recent trend in developed countries’ school curricula has been the transition from disciplinary to generic forms of knowledge, resulting in an emphasis on interdisciplinary organisation and more active forms of learning. Subject specialists are increasingly expected to demonstrate how their subject interconnects and equips pupils with key life skills. Such a change requires a major cultural shift and has been controversial, particularly in Scotland where Curriculum for Excellence, the latest curriculum reform, has seen this debate re-emerge. A detailed empirical case study of one secondary school Social Studies department that has already negotiated these shifts is presented. The case study provides insights into how school and department structures and cultures conducive to a more integrated approach have been developed. Leadership, increased opportunities for teachers to exercise greater autonomy in their work, sources of impetus and support for innovation, and the co-construction of meaning through dialogue are important themes in this process. This case study connects with current policy and provides an insight into strategies that other schools might employ when seeking to embed integrative practices. The department is identified as a significant locus for innovation and one which appears to challenge the norm

    Strong and auxiliary forms of the semi-Lagrangian method for incompressible flows

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    We present a review of the semi-Lagrangian method for advection-diusion and incompressible Navier-Stokes equations discretized with high-order methods. In particular, we compare the strong form where the departure points are computed directly via backwards integration with the auxiliary form where an auxiliary advection equation is solved instead; the latter is also referred to as Operator Integration Factor Splitting (OIFS) scheme. For intermediate size of time steps the auxiliary form is preferrable but for large time steps only the strong form is stable

    Quantitative analysis by renormalized entropy of invasive electroencephalograph recordings in focal epilepsy

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    Invasive electroencephalograph (EEG) recordings of ten patients suffering from focal epilepsy were analyzed using the method of renormalized entropy. Introduced as a complexity measure for the different regimes of a dynamical system, the feature was tested here for its spatio-temporal behavior in epileptic seizures. In all patients a decrease of renormalized entropy within the ictal phase of seizure was found. Furthermore, the strength of this decrease is monotonically related to the distance of the recording location to the focus. The results suggest that the method of renormalized entropy is a useful procedure for clinical applications like seizure detection and localization of epileptic foci.Comment: 10 pages, 5 figure
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