1,700 research outputs found

    Chemical engineering and industrial ecology: Remanufacturing and recycling as process systems

    Get PDF
    Climate change and resource scarcity are just two of the planetary crises that make radical socio-economic change essential if human society is to be sustainable. Chemical engineering is a skill-set that can make a unique contribution to the socio-economic transition, going beyond new technological processes to provide a system-level understanding of economic activities from the perspective of industrial ecology. This paper provides an example by applying process system analysis to the use, re-use, remanufacturing, and recycling of material products. Unlike the ‘circular economy’ approach, the analysis starts from the stock of goods and materials in use in the economy and models the flows required to build up, operate, and maintain the stock. Metrics are developed to account for the effect of stock growth on demand for materials. The significance of the analysis is illustrated for four metals whose industrial ecologies are at different levels of maturity: lead, copper, aluminium, and lithium. Extending product life through re-use and remanufacturing is crucial for resource efficiency, using labour to reduce demand for energy and non-renewable resources. If end-of-life products are processed to recover individual elements, the cost penalties increase rapidly with the decreasing concentration of valuable materials and increasing number of materials in the mixture. Thus, shifting from a linear economy (make−use−dispose) to closed-loop use of materials involves rethinking product design to reduce the number of materials used. Material substitution to reduce demand for scarce materials needs to look beyond equivalence of function to consider changing patterns of use in the regenerative economy

    Iron, Steel and Aluminium in the UK: Material Flows and their Economic Dimensions. Final Project Report

    Get PDF

    Slowing rates of regional exhumation in the western Himalaya: fission track evidence from the Indus Fan

    Get PDF
    Weuse apatite fission track ages from sediments recovered by the International Ocean Discovery Program in the Laxmi Basin, Arabian Sea, to constrain exhumation rates in the western Himalaya and Karakoram since 15.5 Ma. With the exception of a Triassic population in the youngest 0.93 Ma samples supplied from western Peninsular India, apatite fission track ages are overwhelmingly Cenozoic, largely <25 Ma, consistent with both a Himalaya–Karakoram source and rapid erosion. Comparison of the minimum cooling age of each sample with depositional age (lag time) indicates an acceleration in exhumation between 7.8 and 7.0 Ma, with lag times shortening from ∼6.0 Myr at 8.5–7.8 Ma to being within error of zero between 7.0 and 5.7 Ma. Sediment supply at 7.0–5.7 Mawas largely from the Karakoram, and to a lesser extent the Himalaya, based on U–Pb zircon ages from the same samples. This time coincides with a period of drying in the Himalayan foreland caused by weaker summermonsoons andWesterly winds. It also correlates with a shift of erosion away from the Karakoram, Kohistan and the Tethyan Himalaya towards more erosion of the Lesser and Greater Himalaya and Nanga Parbat, as shown by zircon U–Pb provenance data, and especially after 5.7 Ma based on Nd isotope data. Samples younger than 5.7 Ma have lag times of ∼4.5 Myr, similar to Holocene Indus delta sediments

    Party finance reform as constitutional engineering? The effectiveness and unintended consequences of party finance reform in France and Britain

    Get PDF
    In both Britain and France, party funding was traditionally characterized by a laissez faire approach and a conspicuous lack of regulation. In France, this was tantamount to a 'legislative vacuum'. In the last two decades, however, both countries have sought to fundamentally reform their political finance regulation regimes. This prompted, in Britain, the Political Parties, Elections and Referendums Act 2000, and in France a bout of 'legislative incontinence' — profoundly transforming the political finance regime between 1988 and 1995. This article seeks to explore and compare the impacts of the reforms in each country in a bid to explain the unintended consequences of the alternative paths taken and the effectiveness of the new party finance regime in each country. It finds that constitutional engineering through party finance reform is a singularly inexact science, largely due to the imperfect nature of information, the limited predictability of cause and effect, and the constraining influence of non-party actors, such as the Constitutional Council in France, and the Electoral Commission in Britain

    Slip-velocity of large neutrally-buoyant particles in turbulent flows

    Full text link
    We discuss possible definitions for a stochastic slip velocity that describes the relative motion between large particles and a turbulent flow. This definition is necessary because the slip velocity used in the standard drag model fails when particle size falls within the inertial subrange of ambient turbulence. We propose two definitions, selected in part due to their simplicity: they do not require filtration of the fluid phase velocity field, nor do they require the construction of conditional averages on particle locations. A key benefit of this simplicity is that the stochastic slip velocity proposed here can be calculated equally well for laboratory, field, and numerical experiments. The stochastic slip velocity allows the definition of a Reynolds number that should indicate whether large particles in turbulent flow behave (a) as passive tracers; (b) as a linear filter of the velocity field; or (c) as a nonlinear filter to the velocity field. We calculate the value of stochastic slip for ellipsoidal and spherical particles (the size of the Taylor microscale) measured in laboratory homogeneous isotropic turbulence. The resulting Reynolds number is significantly higher than 1 for both particle shapes, and velocity statistics show that particle motion is a complex non-linear function of the fluid velocity. We further investigate the nonlinear relationship by comparing the probability distribution of fluctuating velocities for particle and fluid phases

    Tawney and the third way

    Get PDF
    From the 1920s to the 1950s R. H. Tawney was the most influential socialist thinker in Britain. He articulated an ethical socialism at odds with powerful statist and mechanistic traditions in British socialist thinking. Tawney's work is thus an important antecedent to third way thinking. Tawney's religiously-based critique of the morality of capitalism was combined with a concern for detailed institutional reform, challenging simple dichotomies between public and private ownership. He began a debate about democratizing the enterprise and corporate governance though his efforts fell on stony ground. Conversely, Tawney's moralism informed a whole-hearted condemnation of market forces in tension with both his concern with institutional reform and modern third way thought. Unfortunately, he refused to engage seriously with emergent welfare economics which for many social democrats promised a more nuanced understanding of the limits of market forces. Tawney's legacy is a complex one, whose various elements form a vital part of the intellectual background to current third way thinking

    Epidemiology of Sarcopenia and Frailty

    Get PDF
    Sarcopenia and frailty are common in older persons and pose particular challenges for health and social care systems especially in the context of global population ageing. Sarcopenia, the loss of skeletal muscle mass, strength and function with age is associated with adverse individual physical and metabolic changes contributing to morbidity and mortality. The health and socioeconomic implications of sarcopenia are also considerable. Sarcopenia is a core component of physical frailty that together impact negatively on an individual’s capability to live independently. Frailty is a biological syndrome of low reserve and resistance to stressors resulting from cumulative declines across multiple physiological systems that collectively predispose an individual to adverse outcomes. Frailty develops along a continuum from independence through to death as physiological reserves progressively diminish an individual’s capacity to recover from an acute insult or illness. Managing sarcopenia and frailty involves the multidisciplinary led completion of a comprehensive care plan that is patient centred, responsive to the needs of the patient and adaptable therefore enabling an individual to maintain their independence

    Not just the right to a wheelchair but the right wheelchair-improving Brazilian wheelchair service delivery

    Get PDF
    © 2017 The authors and IOS Press. All rights reserved. This paper discusses the barriers encountered before and after the implementation of good practice in the delivery of wheelchair provision services in Belo Horizonte city, Brazil. The results demystify some participants' initial idea that using an assessment form might take significantly more time. Major barriers to implementation had regard to the assessment of pressure sores and a lack of wheelchair suppliers

    Not just the right to a wheelchair but the right wheelchair - improving Brazilian wheelchair service delivery

    Get PDF
    This paper discusses the barriers encountered before and after the implementation of good practice in the delivery of wheelchair provision services in Belo Horizonte city, Brazil. The results demystify some participants' initial idea that using an assessment form might take significantly more time. Major barriers to implementation had regard to the assessment of pressure sores and a lack of wheelchair suppliers
    • …
    corecore