39 research outputs found

    Metrics for optimising the multi-dimensional value of resources recovered from waste in a circular economy: A critical review

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    © 2017 The Authors - Established assessment methods focusing on resource recovery from waste within a circular economy context consider few or even a single domain/s of value, i.e. environmental, economic, social and technical domains. This partial approach often delivers misleading messages for policy- and decision-makers. It fails to accurately represent systems complexity, and obscures impacts, trade-offs and problem shifting that resource recovery processes or systems intended to promote circular economy may cause. Here, we challenge such partial approaches by critically reviewing the existing suite of environmental, economic, social and technical metrics that have been regularly observed and used in waste management and resource recovery systems' assessment studies, upstream and downstream of the point where waste is generated. We assess the potential of those metrics to evaluate ‘complex value’ of materials, components and products, i.e., the holistic sum of their environmental, economic, social and technical benefits and impacts across the system. Findings suggest that the way resource recovery systems are assessed and evaluated require simplicity, yet must retain a suitable minimum level of detail across all domains of value, which is pivotal for enabling sound decision-making processes. Criteria for defining a suitable set of metrics for assessing resource recovery from waste require them to be simple, transparent and easy to measure, and be both system- and stakeholder-specific. Future developments must focus on providing a framework for the selection of metrics that accurately describe (or at least reliably proxy for) benefits and impacts across all domains of value, enabling effective and transparent analysis of resource recovery form waste in circular economy systems.We gratefully acknowledge support of the UK Natural Environ-ment Research Council (NERC) and the UK Economic and SocialResearch Council (ESRC) who funded this work in the context of‘Complex Value Optimisation for Resource Recovery’(CVORR)project (Grant No. NE/L014149/1)

    The microstructure of tensile kinks in cadmium crystals

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    Occurrence and geochemistry of metamafic rocks from the Forquilha Eclogite Zone, central Ceara (NE Brazil): geodynamic implications

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    In the northern region of the Borborema Province, a 30 km-long mafic/ultramafic belt of high pressure (HP) rocks called the Forquilha Eclogite Zone has been recently discovered in the Central Domain of Ceara State. The belt comprises three groups of rocks: ( I) garnet amphibolites, (2) retrograded eclogites and (3) clinopyroxene-garnet amphibolites, all of them being hosted in garnet +/- kyanite + sillimanite schists and orthogneisses which are often migmatized. The geochemical analyses of 30 representative samples confirm differences among the three groups that were initially classified by petrography. The garnet amphibolites are the most depleted rocks, with relatively flat rare earth element (REE)(PM) pattern and (SPIDER)(PM) pattern with negative Rb, Th, Nb, Sr and Zr anomalies. It is the most fractionated group, ranging from picrobasalts to andesites. Fractional crystallization and mineral accumulation are indicated by Eu and Sr anomalies. The data show geochemical affinities with,. island-arc basalts. The retrograded eclogites display flat (REE)(PM), but without Eu anomalies. Nb/La ratios are low and variable, as for slightly enriched MORB from ocean floor or intra-oceanic back-arc environments. However, a genetic link with the Group 1 rocks cannot be completely discarded. The clinopyroxene-garnet amphibolites are the most enriched group. (REE)(PM) and (SPIDER)(PM) patterns show many features of alkaline basalts. In the Nb/Yb versus Th/Yb diagram the data cluster near the E-MORB standard. Several geochemical aspects of these rocks fit well those from the HP/UHP Pan-African/Brasiliano Suture Zone in the Dahomeyides/Hoggar regions of West Africa. However, differences in their extent and lack of alignment preclude a direct correlation among these zones. Copyright (C) 2010 John Wiley & Sons, Ltd.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    High-pressure granulites from Carire, Borborema Province, NE Brazil: Tectonic setting, metamorphic conditions and U-Pb, Lu-Hf and Sm-Nd geochronology

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    In the northwest region of the Ceara Central Domain, Borborema Province, an elongate area of mylonitic diorites and granodiorites is structurally controlled by NE-SW-trending strike-slip faults. Granitic material and layers and lenses of felsic and mafic granulites occur along the main shear zones. We present and discuss petrographic, geothermobarometric. and geochronological (LA-MC-ICPMS U-Pb and Lu-Hf in zircon and Sm-Nd whole-rock) data for these rocks. Felsic granulites are composed of orthopyroxene + clinopyroxene + plagioclase + quartz +/- hornblende +/- garnet +/- biotite +/- feldspar, while the mafic granulites comprise clinopyroxene + plagioclase + garnet + hornblende +/- rutile +/- quartz. The P-T conditions recorded range from 9.4 to 83 kbars and from 804 to 870 degrees C for the felsic granulites and from 13.6 to 10.2 kbars and 910 to 750 degrees C for the mafic granulites. U-Pb zircon ages of granodiorite host rocks are 2157 and 2044 Ma. The felsic granulites yield a U-Pb age of 2110 Ma, while the mafic granulites yield U-Pb zircon ages of 613 and 589 Ma for the metamorphic recrystallization. Sm-Nd and Lu-Hf T-DM ages for the mafic granulites are similar (1.6-1.3 Ga) and share positive values of epsilon(Nd) and epsilon(Hf), which suggests that these mafic rocks were derived from a juvenile Mesoproterozoic crust. In addition, the felsic granulites and the granodiorites have similar TDM-Nd and U-Pb ages (with positive values of epsilon(Nd)), indicating a Paleoproterozoic mantle source for these rocks. (C) 2012 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Relics of eclogite facies assemblages in the Ceara Central Domain, NW Borborema Province, NE Brazil: Implications for the assembly of West Gondwana

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    The Borborema Province, in the NE of Brazil, is a rather complex piece in the Brazil-Africa puzzle as it represents the junction of the Dahomeyide/Pharusian, Central African, Aracuai and Brasilia fold belts located between the West-African/Sao Luis, Congo/Sao Francisco and Amazonas craton. The correlation between the Dahomeyides from W-Africa (Ghana, Benin, Togo, and Mali) and the Borborema Province involves the Medio Coreau and Central Ceara domains. The inferred continuation of the main oceanic suture zone exposed in the Dahomeyides of W Africa is buried beneath the Phanerozoic Parnaiba Basin in Brazil (northwest of the Medio Coreau domain) where some high density gravity anomalies may represent hidden remnants of an oceanic suture. In addition to this major suture a narrow, nearly continuous strip composed of mainly mafic pods containing relics of eclogite-facies assemblages associated with partially migmatized granulite-facies metapelitic gneisses has been found further east in the NW Borborema Province. These high pressure mafic rocks, interpreted as retrograded eclogites, are located between the Transbrasiliano Lineament and the Santa Quiteria continental arc and comprise primitive to evolved arc-related rocks with either arc- or MORB-type imprints that can indicate either deep subduction of oceanic lithosphere or roots of continental and oceanic magmatic arcs. Average peak P-T conditions under eclogite-facies metamorphism (T=770 degrees C and P = 17.3 kbar) were estimated using garnet-clinopyroxene thermometry and Jd content in clinopyroxene. Transition to granulite-facies conditions, as well as later widespread re-equilibration under amphibolite facies, were registered both in the basic and the metapelitic rocks and suggest a clockwise P-T path characterized by an increase in temperature followed by strong decompression. A phenomenon possibly related to the exhumation of a highly thickened crust associated with the suturing of the Medio Coreau and Central Ceara domains, two distinct crustal blocks separated by the Transbrasiliano Lineament. (C) 2009 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.FAPESP[03/07663-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP[07/58535]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq/MCT[42.0222/2005-7

    Comparison of arterial blood pressure measurements and hypertension scores obtained by use of three indirect easurement devices in hospitalized dogs

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    Objective—To evaluate the agreement of blood pressure measurements and hypertension scores obtained by use of 3 ndirect arterial blood pressure measurement devices in hospitalized dogs. Design—Diagnostic test evaluation. Animals—29 client-owned dogs. Procedures—5 to 7 consecutive blood pressure readings were obtained from each dog on each of 3 occasions with a Doppler ultrasonic flow detector, a standard oscillometric device (STO), and a high-definition oscillometric device (HDO). Results—When the individual sets of 5 to 7 readings were evaluated, the coefficient of variation for systolic arterial blood pressure (SAP) exceeded 20% for 0% (Doppler), 11% (STO), and 28% (HDO) of the sets of readings. After readings that exceeded a 20% coefficient of variation were discarded, repeatability was within 25 (Doppler), 37 (STO), and 39 (HDO) mm Hg for SAP. Correlation of mean values among the devices was between 0.47 and 0.63. Compared with Doppler readings, STO underestimated and HDO overestimated SAP. Limits of agreement between mean readings of any 2 devices were wide. With the hypertension scale used to score SAP, the intraclass correlation of scores was 0.48. Linear-weighted inter-rater reliability between scores was 0.40 (Doppler vs STO), 0.38 (Doppler vs HDO), and 0.29 (STO vs HDO). Conclusions and Clinical Relevance—Results of this study suggested that no meaningful clinical comparison can be made between blood pressure readings obtained from the same dog with different indirect blood pressure measurement devices
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