360 research outputs found

    Study of the desorption of ethylene oxide fixed on various materials during sterilization by a new procedure

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    A continuous sterilization process using ethylene oxide was studied in comparison with a classical method in order to evaluate gas retention as a function of time and temperature on polyethylene, PVC, and rubber materials

    Money, use and experience: Identifying the mechanisms through which ecosystem services contribute to wellbeing in coastal Kenya and Mozambique

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    Despite extensive recent research elucidating the complex relationship between ecosystem services and human wellbeing, little work has sought to understand how ecosystem services contribute to wellbeing and poverty alleviation. This paper adopts concepts from the “Theory of Human Need” and the “Capability Approach” to both identify the multitude of links occurring between ecosystem services and wellbeing domains, and to understand the mechanisms through which ecosystem services contribute to wellbeing. Focus Group Discussions (N = 40) were carried out at 8 sites in Mozambique and Kenya to elicit how, why, and to what extent benefits derived from ecosystem services contribute to different wellbeing domains. Our results highlight three types of mechanisms through which ecosystem services contribute to wellbeing, monetary, use and experience. The consideration of these mechanisms can inform the development of interventions that aim to protect or improve flows of benefits to people. Firstly, interventions that support multiple types of mechanisms will likely support multiple domains of wellbeing. Secondly, overemphasising certain types of mechanism over others could lead to negative social feedbacks, threatening the future flows of ecosystem services. Finally, the three mechanism types are interlinked and can act synergistically to enhance the capacities of individuals to convert ecosystem services to wellbeing

    Surface-induced charge state conversion of nitrogen-vacancy defects in nanodiamonds

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    We present a study of the charge state conversion of single nitrogen-vacancy (NV) defects hosted in nanodiamonds (NDs). We first show that the proportion of negatively-charged NV^{-} defects, with respect to its neutral counterpart NV0^{0}, decreases with the size of the ND. We then propose a simple model based on a layer of electron traps located at the ND surface which is in good agreement with the recorded statistics. By using thermal oxidation to remove the shell of amorphous carbon around the NDs, we demonstrate a significant increase of the proportion of NV^{-} defects in 10-nm NDs. These results are invaluable for further understanding, control and use of the unique properties of negatively-charged NV defects in diamondComment: 6 pages, 4 figure

    Revisiting the relationships between human well-being and ecosystems in dynamic social-ecological systems: Implications for stewardship and development

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    This is the final version. Available from Cambridge University Press via the DOI in this record.Non-technical summary We argue that the ways in which we as humans derive well-being from nature - for example by harvesting firewood, selling fish or enjoying natural beauty - feed back into how we behave towards the environment. This feedback is mediated by institutions (rules, regulations) and by individual capacities to act. Understanding these relationships can guide better interventions for sustainably improving well-being and alleviating poverty. However, more attention needs to be paid to how experience-related benefits from nature influence attitudes and actions towards the environment, and how these relationships can be reflected in more environmentally sustainable development projects. Technical summary In the broad literatures that address the linked challenge of maintaining ecosystem integrity while addressing poverty and inequality, there is still a need to investigate how linkages and feedbacks between ecosystem services and well-being can be taken into account to ensure environmental sustainability and improved livelihoods. We present a conceptual model towards a dynamic and reciprocal understanding of the feedbacks between human well-being and ecosystems. The conceptual model highlights three mechanisms through which people derive benefits from ecosystems (use, money and experience), and illustrates how these benefits can affect values, attitudes and actions towards ecosystems. Institutions and agency determine access to and distribution of benefits and costs, and also present barriers or enabling factors for individual or collective action. The conceptual model synthesises insights from existing but mostly separate bodies of literature on well-being and the benefits humans derive from ecosystems, and reveals gaps and areas for future research. Two case studies illustrate how recognizing the full feedback loop between how ecosystems support human well-being and how people behave towards those ecosystems, as well as intervention points within the loop, can guide better action for sustainable poverty alleviation and stewardship of the biosphere.Swedish Research CouncilSwedish Research Counci

    The Gendered Nature of Ecosystem Services

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    This is the final version. Available from Elsevier via the DOI in this record. This article assesses the extent to which our conceptualisation, understanding and empirical analysis of ecosystem services are inherently gendered; in other words, how they might be biased and unbalanced in terms of their appreciation of gender differences. We do this by empirically investigating how women and men are able to benefit from ecosystem services across eight communities in coastal Kenya and Mozambique. Our results highlight different dimensions of wellbeing affected by ecosystem services, and how these are valued differently by men and women. However, it is not just the division of costs and benefits of ecosystem services that is gendered. Using a heuristic device of the ‘ecosystem-wellbeing chain’ we explain patterns within our primary data as an outcome of gendered knowledge systems, gendered behavioural expectations, gendered access to resources and gendered institutions. We conclude that this holistic, gendered understanding of ecosystem services is important not just for how ecosystem services are conceptualised, but also for the development and implementation of sustainable and equitable policy and interventions.Natural Environment Research Council (NERC)Ecosystem Services for Poverty Alleviation (ESPA)Economic and Social Research Council (ESRC

    Light depolarization effects in tip enhanced Raman spectroscopy of silicon (001) and gallium arsenide (001)

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    We report on the effects of light depolarization induced by sharp metallic tips in Tip-Enhanced Raman Spectroscopy (TERS). Experiments on Si(001) and GaAs(001) crystals show that the excitation field depolarization induces a selective enhancement of specific Raman modes, depending on their Raman tensor symmetry. A complete polarization analysis of the light backscattered from the tip confirms the TERS findings. The spatial confinement of the depolarization field is studied and its dependence on the excitation wavelength and power are explored

    Save reefs to rescue all ecosystems

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    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recor

    Hydrostatic strain enhancement in laterally confined SiGe nanostripes

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    Strain-engineering in SiGe nanostructures is fundamental for the design of optoelectronic devices at the nanoscale. Here we explore a new strategy, where SiGe structures are laterally confined by the Si substrate, to obtain high tensile strain avoiding the use of external stressors, and thus improving the scalability. Spectro-microscopy techniques, finite element method simulations and ab initio calculations are used to investigate the strain state of laterally confined Ge-rich SiGe nano-stripes. Strain information is obtained by tip enhanced Raman spectroscopy with an unprecedented lateral resolution of ~ 30 nm. The nano-stripes exhibit a large tensile hydrostatic strain component, which is maximum at the center of the top free surface, and becomes very small at the edges. The maximum lattice deformation is larger than the typical values of thermally relaxed Ge/Si(001) layers. This strain enhancement originates from a frustrated relaxation in the out-of-plane direction, resulting from the combination of the lateral confinement induced by the substrate side walls and the plastic relaxation of the misfit strain in the (001) plane at the SiGe/Si interface. The effect of this tensile lattice deformation at the stripe surface is probed by work function mapping, performed with a spatial resolution better than 100 nm using X-ray photoelectron emission microscopy. The nano-stripes exhibit a positive work function shift with respect to a bulk SiGe alloy, quantitatively confirmed by electronic structure calculations of tensile strained configurations. The present results have a potential impact on the design of optoelectronic devices at a nanometer length scale.Comment: 40 pages, 11 figures, submitted to Physical Review
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