516 research outputs found

    Pharmaceuticals and Personal Care Products in an Effluent-Dominated Stream: Seasonal Variability and Downstream Fate

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    Wastewater treatment plant (WWTP) effluents are major sources of pharmaceuticals and personal care products (PPCPs) in the environment and effluentdominated streams (EDSs) represent worst-case scenarios for PPCP exposures to aquatic organisms. The concentrations of PPCPs downstream from a WWTP can be altered by dilution and fate processes such as biodegradation, photodegradation and sorption. The relative importance of these processes depends on the individual PPCPs and environmental variables that vary seasonally. The primary objective of this study was to determine the concentrations of selected PPCPs in an EDS as a function of season and distance from a WWTP with the hypothesis being that the downstream attenuation of the PPCPs would vary based on their corresponding physicochemical properties. A secondary objective was to evaluate the ability of the constructed wetlands located between the plant and creek to reduce PPCP concentrations. Samples were collected seasonally from above and below the East Canyon Water Reclamation Facility (ECWRF) and within the constructed wetlands for selected PPCPs. Except for caffeine, downstream PPCP concentrations were higher than upstream, indicating that the ECWRF effluent is the major source of PPCPs in East Canyon Creek. Generally, the highest PPCP concentrations in the stream were observed in July and the lowest in May corresponding to the times of lowest and highest ratio of stream to effluent flows, respectively. Dilution was the major factor associated with the declining PPCP concentrations downstream of the ECWRF but the extent of decline varied between compounds suggesting other fate mechanisms also play a role. Sorption of PPCPs to wetland sediments was greater than stream sediments but overall the retention time within the wetlands was too short to significantly reduce the amount of PPCPs moving into the stream. The observed concentrations of individual PPCPs in East Canyon Creek were lower than those expected to negatively impact the health of aquatic organisms but mixture effects are still a potential concern

    Searching and fixating: scale-invariance vs. characteristic timescales in attentional processes

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    In an experiment involving semantic search, the visual movements of sample populations subjected to visual and aural input were tracked in a taskless paradigm. The probability distributions of saccades and fixations were obtained and analyzed. Scale-invariance was observed in the saccadic distributions, while the fixation distributions revealed the presence of a characteristic (attentional) time scale for literate subjects. A detailed analysis of our results suggests that saccadic eye motions are an example of Levy, rather than Brownian, dynamics.Comment: Accepted to Europhysics Letters (2011

    Energy in the home: Everyday life and the effect on time of use

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    The application of building simulation and modelling is becoming more widespread, particularly in the analysis of residential buildings. The energy consumption and control of systems in residential buildings are tightly linked to the behaviour of people, arguably more so than in commercial buildings which have traditionally been the preserve of building simulation analysis. The input profiles used in simulation pay little attention to the link between numerical characterisations of observed ‘behaviour’ and the way people actually live in the home. Understanding this is important if we are to improve the modelling of buildings, gain greater insight into energy consumption and make better decisions about future energy production and generation. This paper explores this link by combining conventional numerical analysis of appliance data with insights from the ethnographic study of families in 20 UK homes. Ethnographic insights provide a context to the analysis and understanding of monitoring data that would not otherwise be possible. Importantly, this paper highlights the need to rethink previously static notions of simulation input, such as occupancy and individual appliance use

    The Theory of Critical Distances to assess the effect of cracks/manufacturing defects on the static strength of 3D-printed concrete

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    The present paper deals with the use of the Theory of Critical Distances to model the detrimental effect of cracks and manufacturing defects in 3D-printed concrete subjected to static loading. The robustness of the proposed approach was assessed against a number of experimental results that were generated by testing, under three-point bending, 3D-printed rectangular section specimens weakened by saw-cut crack-like sharp notches, surface roughness (due to the extrusion filaments) and manufacturing defects. The sound agreement between experiments and predictive model allowed us to demonstrate that the Theory of Critical Distances is not only a reliable design approach, but also a powerful tool suitable for guiding and informing effectively the additive manufacturing process

    The Theory of Critical Distances to perform the static assessment of 3D-printed concrete weakened by manufacturing defects and cracks

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    The Theory of Critical Distances groups together a number of approaches postulating that, in cracked/notched materials subjected to static loading, breakage takes place as soon as a critical length-dependent effective stress exceeds the material tensile strength. The characteristic length used by the Theory of Critical Distances is a material property that can directly be estimated from the ultimate tensile strength and the plane strain fracture toughness. In the present investigation, based on a large number of bespoke experimental results, it is demonstrated that the Theory of Critical Distances is successful also in quantifying the detrimental effect of cracks and manufacturing defects in 3D-printed concrete subjected to Mode I static loading

    Supporting people living with dementia and faecal incontinence.

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    This document is the Accepted Manuscript version of the following article: Bridget Russell, et al, 'Supporting people living with dementia and faecal incontinence', British Journal of Community Nursing, Vol. 22 (3): 110-114, March 2017, doi: http://www.magonlinelibrary.com/doi/pdf/10.12968/bjcn.2017.22.3.110. © 2017 MA Healthcare Ltd.There are approximately 17 500 care homes in the UK which are home to about 487 000 older people, the majority are women aged 80 years or older (Care Quality Commission, 2010). As many as 80% of care home residents may have dementia, though this is not always documented, (Gordon et al, 2014). In England the majority of care homes do not have on site nursing provision and rely on community nurse specialists for support when residents require nursing advice and care. The support of people living in care homes is a well-documented problem (Taunton et al, 2005; Heckenberg, 2008; Saga, 2014) and how well they are managed is often seen as a marker of the quality of care (Care Quality Commission, 2010). Faecal incontinence can be a source of distress, discomfort, lead to complications such as skin breakdown and infection and affect an individual’s sense of dignity and self-worth. It can also be a challenging aspect of care for those who work in care homes.Non peer reviewe

    Multidisciplinary research: should effort be the measure of success?

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    Energy demand reduction and flexible demand from dwellings will play a critical role in achieving a low-carbon future. There remain many unanswered questions around the interaction of people with their environment and the technical systems that service them and, as a result, multidisciplinary research is a principal component of research funding internationally. However, relatively little published work considers the operational issues in undertaking epistemologically diverse, academic research projects. This paper makes a contribution by quantifying the operational effort involved in data collection on a large multidisciplinary project and connecting the operational issues encountered to knowledge production. It is found that the cost of the data gathering is £46,000/home, and participants can give upwards of 217 hours of their time per house engaging with data-gathering activities. The rate of knowledge production is found to be approximately three publication/full-time equivalents (FTE) over the lifetime of the project and the risk to generating interdisciplinary insights is shown to be dependent on largely unforeseeable operational issues that compound the characteristic differences in the collection of the data utilized by social and technical research communities

    Reducing and managing faecal incontinence in people with advanced dementia who are resident in care homes: protocol for a realist synthesis.

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    INTRODUCTION: Faecal incontinence (FI) is the involuntary loss of liquid or solid stool that is a social or hygienic problem. The prevalence of FI in residents of care homes is high, but it is not an inevitable consequence of old age or dementia. There is good evidence on risk factors, but few studies provide evidence about effective interventions. There is a need to understand how, why, and in what circumstances particular programmes to reduce and manage FI are effective (or not) for people with dementia. The purpose of this review is to identify which (elements of the) interventions could potentially be effective, and examine the barriers and facilitators to the acceptability, uptake and implementation of interventions designed to address FI in people with dementia who are resident in care homes. METHODS AND ANALYSIS: A realist synthesis approach to review the evidence will be used which will include studies on continence, person-centred care, implementation research in care homes, workforce and research on care home culture. An iterative four-stage approach is planned. Phase 1: development of an initial programme theory or theories that will be 'tested' through a first scoping of the literature and consultation with five stakeholder groups (care home providers, user representatives, academics and practice educators, clinicians with a special interest in FI and continence specialists). Phase 2: a systematic search and analysis of published and unpublished evidence to test and develop the programme theories identified in phase 1. Phase 3: validation of programme theory/ies with a purposive sample of participants from phase 1. ETHICS AND DISSEMINATION: The overall protocol does not require ethical review. The University research ethics committee will review interviews conducted as part of phase 1 and 3. The final fourth phase will synthesise and develop recommendations for practice and develop testable hypotheses for further research

    Hardened properties of high-performance printing concrete

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    This paper presents the hardened properties of a high-performance fibre-reinforced fine-aggregate concrete extruded through a 9 mm diameter nozzle to build layer-by-layer structural components in a printing process. The printing process is a digitally controlled additive method capable of manufacturing architectural and structural components without formwork, unlike conventional concrete construction methods. The effects of the layering process on density, compressive strength, flexural strength, tensile bond strength and drying shrinkage are presented together with the implication for mix proportions. A control concrete (mould-cast specimens) had a density of approximately 2250 kg/m3, high strength (107 MPa in compression, 11 MPa in flexure) and 3 MPa in direct tension, together with a relatively low drying shrinkage of 175 μm (cured in water) and 855 μm (cured in a chamber at 20 °C and 60% relative humidity) at 184 days. In contrast well printed concrete had a density of 2350 kg/m3, compressive strength of 75–102 MPa, flexural strength of 6–17 MPa depending on testing direction, and tensile bond strength between layers varying from 2.3 to 0.7 MPa, reducing as the printing time gap between layers increased. The well printed concrete had significantly fewer voids greater than 0.2 mm diameter (1.0%) when compared with the mould-cast control (3.8%), whilst samples of poorly printed material had more voids (4.8%) mainly formed in the interstices between filaments. The additive extrusion process was thus shown to retain the intrinsic high performance of the material
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