2,168 research outputs found

    Experimental techniques for ductile damage characterisation

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    Ductile damage in metallic materials is caused by the nucleation, growth and coalesce of voids and micro-cracks in the metal matrix when it is subjected to plastic strain. A considerable number of models have been proposed to represent ductile failure focusing on the ultimate failure conditions; however, only some of them study in detail the whole damage accumulation process. The aim of this work is to review experimental techniques developed by various authors to measure the accumulation of ductile damage under tensile loads. The measurement methods reviewed include: stiffness degradation, indentation, microstructure analysis, ultrasonic waves propagation, X-ray tomography and electrical potential drop. Stiffness degradation and indentation techniques have been tested on stainless steel 304L hourglass-shaped samples. A special interest is placed in the Continuum Damage Mechanics approach (CDM) as its equations incorporate macroscopic parameters that can represent directly the damage accumulation measured in the experiments. The other main objective lies in identifying the strengths and weaknesses of each technique for the assessment of materials subjected to different strain-rate and temperature conditions

    Linking Environmental Sustainability and Healthcare: The Effects of an Energy Saving Intervention in Two Hospitals

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    Set in a real organisational setting, this study examines the challenges of implementing environmentally sustainable behaviour in healthcare. It evaluates the success of a real energy saving behaviour change intervention, based on social marketing principles, which targeted the employees of two National Health Service (NHS) hospitals. It also explores the intervention benefits for three key stakeholders: the organisation/hospitals, hospital employees and patients. A rich secondary dataset containing actual workplace behaviour measures (collected via observations) and self-reported data from employee interviews and patient questionnaires is used for this purpose. The intervention encouraged three employee energy saving actions (called TLC actions): (1) Turn off machines, (2) Lights out when not needed, and (3) Close doors when possible; which led to energy savings and carbon reduction for the two hospitals. Hospital employees reported a greater level of work efficiency as a result of engaging in TLC actions, which increased the 'quiet time' periods in both hospitals. Indirectly, employees' TLC actions also improved patients' quality of sleep (which in turn is positively associated with greater patient hospital experience satisfaction). These findings shed light on the benefits of social marketing interventions targeting energy saving behaviour change for multiple stakeholders in healthcare organisations. They also illustrate connections between environmental sustainability and social and political pillars of corporate social responsibility. Additionally, organisational culture was highlighted as a key challenge in changing practices. To encourage long-term sustainable behaviour, this study recommends a pre-intervention assessment of infrastructure and equipment, the communication of expected benefits to motivate higher involvement of employees, the need for internal green champions and the dissemination of post-intervention feedback on various energy saving and patient indicators

    A critical assessment of the "stable indenter velocity" method for obtaining the creep stress exponent from indentation data

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    A technique for evaluating the (steady-state) creep stress exponent (n) from indentation data has come into common use over recent years. It involves monitoring the indenter displacement history under constant load and assuming that, once its velocity has stabilised, the system is in a quasisteady state, with Stage II creep dominating the behaviour. The stress field under the indenter, and the way in which the creep strain field is changing there, are then represented by "equivalent stress" and "equivalent strain rate" values. These are manipulated in a similar manner to that conventionally employed with (uniaxial) creep test data, allowing the stress exponent, n, to be obtained as the gradient of a plot of the logarithm of the equivalent strain rate against the logarithm of the equivalent stress. The procedure is therefore a very simple one, often carried out over relatively short timescales (of the order of an hour or less). However, concerns have been expressed about its reliability, regarding the neglect of primary creep (after a very short initial transient) and about the validity of representing the stress and strain rate via these "equivalent" values. In this paper, comprehensive experimental data (both from a conventional, uniaxial loading set-up and from instrumented indentation over a range of conditions) are presented for two materials, focussing entirely on ambient temperature testing. This is supplemented by predictions from numerical (FEM) modelling. It is shown that the methodology is fundamentally flawed, commonly giving unreliable (and often very high) values for n. The reasons for this are outlined in some detail. An attempt is made to identify measures that might improve the reliability of the procedure, although it is concluded that there is no simple analysis of this type that can be recommended.RCUK, Othe

    Linking Environmental Sustainability and Healthcare: The Effects of an Energy Saving Intervention in Two Hospitals

    Get PDF
    Set in a real organisational setting, this study examines the challenges of implementing environmentally sustainable behaviour in healthcare. It evaluates the success of a real energy saving behaviour change intervention, based on social marketing principles, which targeted the employees of two National Health Service (NHS) hospitals. It also explores the intervention benefits for three key stakeholders: the organisation/hospitals, hospital employees and patients. A rich secondary dataset containing actual workplace behaviour measures (collected via observations) and self-reported data from employee interviews and patient questionnaires is used for this purpose. The intervention encouraged three employee energy saving actions (called TLC actions): (1) Turn off machines, (2) Lights out when not needed, and (3) Close doors when possible; which led to energy savings and carbon reduction for the two hospitals. Hospital employees reported a greater level of work efficiency as a result of engaging in TLC actions, which increased the 'quiet time' periods in both hospitals. Indirectly, employees' TLC actions also improved patients' quality of sleep (which in turn is positively associated with greater patient hospital experience satisfaction). These findings shed light on the benefits of social marketing interventions targeting energy saving behaviour change for multiple stakeholders in healthcare organisations. They also illustrate connections between environmental sustainability and social and political pillars of corporate social responsibility. Additionally, organisational culture was highlighted as a key challenge in changing practices. To encourage long-term sustainable behaviour, this study recommends a pre-intervention assessment of infrastructure and equipment, the communication of expected benefits to motivate higher involvement of employees, the need for internal green champions and the dissemination of post-intervention feedback on various energy saving and patient indicators

    Libraries in the Doughnut Economy

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    This chapter unpacks the principles behind Doughnut Economics and explains how libraries can lead a long overdue social transition by incorporating the principles into their policies and operations. The actualization of Doughnut Economics will bring about a positive transformation of people’s behavior, which in turn will shift the focus of the economy from unfettered growth and opportunistic monetization to the well-being of people and biodiversity on the planet. In addition, libraries can help facilitate a redistribution of wealth in its various forms by supporting and promoting knowledge sharing. The chapter concludes with a discussion of five simple acts that drive home the need to put people’s well-being and sustainability at the center of our economic model

    Achieving Resilience for Our Future: Sustainability Practices in Libraries

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    Sustainability is a core value of librarianship. However, sustainability is not an end point but a mindset, a lens through which operational and outreach decisions can be made. This panel presentation aims to inform the audience of how public and academic libraries have organized outreach events to raise their user communities’ understanding of climate change and related issues in terms of sustainability, resilience, and regeneration. This panel will provide examples of sustainability programming, transformative community partnerships, collective responses for climate resilience, green building practices, and instructional course material to guide us on the path to a sustainable mindset in libraries. Resiliency, as a response, will be portrayed in ways that prepare our communities for the disruptions and complexities of living through this unprecedented time. Presenters will identify resources and potential partners that libraries can consider when planning events and relevant services around sustainability in libraries

    Libraries as Sustainability Leaders: ALA\u27s Special Task Force

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    This article discusses the work of the American Library Association (ALA) Special Task Force on Sustainability, which identified 52 recommendations, including the adoption of sustainability as a core value of librarianship. The group aims to promote libraries as catalysts, connectors, and conveners to promote sustainability, resilience, and regeneration. The Task Force is guided by the concept of the triple bottom line, which states that an organization\u27s practices must be not only economically feasible but also socially equitable and environmentally sound. The article also provides examples of how libraries engage in sustainable practices to support the cities and towns they serve

    Libraries as Sustainability Leaders: ALA’s Special Task Force

    Get PDF
    This article discusses the work of the American Library Association (ALA) Special Task Force on Sustainability, which identified 52 recommendations, including the adoption of sustainability as a core value of librarianship. The group aims to promote libraries as catalysts, connectors, and conveners to promote sustainability, resilience, and regeneration. The Task Force is guided by the concept of the triple bottom line, which states that an organization’s practices must be not only economically feasible but also socially equitable and environmentally sound. The article also provides examples of how libraries engage in sustainable practices to support the cities and towns they serve

    MOCVD of hard metallurgical coatings: Examples in the Cr–C–N system

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    All individual phases of the ternary Cr–C–N system including stable and metastable ones can be deposited at low temperature by metalorganic chemical vapor deposition (MOCVD). These growth processes are mainly based on the use of bis(benzene)chromium as chromium source and various co-reactives. Then, from a good control of the reactive gas phase, it is possible to combine these MOCVD processes to grow in the same reactor protective coatings designed with a complex architecture based on polyphased, nanostructured or multilayer structure which exhibit enhanced properties. These deposition processes are described and the main features of the coatings are discussed
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