98 research outputs found

    Differential release of sewage sludge biochar-borne elements by common low-molecular-weight organic acids

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    Biochar materials originated from sewage sludge may contain elevated levels of potentially toxic elements. There was a lack of information on the mobility of biochar-borne elements, as driven by lowmolecular-weight organic acids (LMWOAs) contained in plant root exudates. A batch experiment was conducted to examine the effects of three common LMWOAs on the release of major elements and trace elements with a focus on various potentially toxic trace elements. The results showed that substantial amounts of Al, Mn, Fe, K, Na and Mg were extracted from two sewage sludge-derived biochar materials by the LMWOAs. A much higher release rate of potentially toxic trace elements was observed in the presence of LMWOAs, as compared to reported data using extractants not encountered in root exudates. The LMWOA-driven releasibility of various potentially toxic trace elements was in the following decreasing order: Zn > Ni > Pb > Cu > Cr > Co = Cd. Other trace elements that are subject to mobilization in the presence of LMWOAs included B, Ba, In, Li and Sr except Ba under oxalic acid extraction. Among the three LMWOAs, oxalic acid showed a generally stronger capacity to mobilize these metals. The findings obtained from this study provides new information that can be used for better evaluating the phyto-availability of trace elements bound to sewage sludge-originated biochar materials

    Effective Magnetic Hamiltonian and Ginzburg Criterion for Fluids

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    We develop further the approach of Hubbard and Schofield (Phys.Lett., A40 (1972) 245), which maps the fluid Hamiltonian onto a magnetic one. We show that all coefficients of the resulting effective Landau-Ginzburg-Wilson (LGW) Hamiltonian may be expressed in terms of the compressibility of a reference fluid containing only repulsive interactions, and its density derivatives; we calculate the first few coefficients in the case of the hard-core reference fluid. From this LGW-Hamiltonian we deduce approximate mean-field relations between critical parameters and test them on data for Lennard-Jones, square-well and hard-core-Yukawa fluids. We estimate the Ginzburg criterion for these fluids.Comment: 4 pages, LaTeX, To appear in Phys.Rev.

    A study of facilities and fixtures for testing of a high speed civil transport wing component

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    A study was performed to determine the feasibility of testing a large-scale High Speed Civil Transport wing component in the Structures and Materials Testing Laboratory in Building 1148 at NASA Langley Research Center. The report includes a survey of the electrical and hydraulic resources and identifies the backing structure and floor hard points which would be available for reacting the test loads. The backing structure analysis uses a new finite element model of the floor and backstop support system in the Structures Laboratory. Information on the data acquisition system and the thermal power requirements is also presented. The study identified the hardware that would be required to test a typical component, including the number and arrangement of hydraulic actuators required to simulate expected flight loads. Load introduction and reaction structure concepts were analyzed to investigate the effects of experimentally induced boundary conditions

    Achieving sustainable quality in maternity services – using audit of incontinence and dyspareunia to identify shortfalls in meeting standards

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    BACKGROUND: Some complications of childbirth (for example, faecal incontinence) are a source of social embarrassment for women, and are often under reported. Therefore, it was felt important to determine levels of complications (against established standards) and to consider obstetric measures aimed at reducing them. METHODS: Clinical information was collected on 1036 primiparous women delivering at North and South Staffordshire Acute and Community Trusts over a 5-month period in 1997. A questionnaire was sent to 970 women which included self-assessment of levels of incontinence and dyspareunia prior to pregnancy, at 6 weeks post delivery and 9 to 14 months post delivery. RESULTS: The response rate was 48%(470/970). Relatively high levels of obstetric interventions were found. In addition, the rates of instrumental deliveries differed between the two hospitals. The highest rates of postnatal symptoms had occurred at 6 weeks, but for many women problems were still present at the time of the survey. At 9–14 months high rates of dyspareunia (29%(102/347)) and urinary incontinence (35%(133/382)) were reported. Seventeen women (4%) complained of faecal incontinence at this time. Similar rates of urinary incontinence and dyspareunia were seen regardless of mode of delivery. CONCLUSION: Further work should be undertaken to reduce the obstetric interventions, especially instrumental deliveries. Improvements in a number of areas of care should be undertaken, including improved patient information, improved professional communication and improved professional recognition and management of third degree tears. It is likely that these measures would lead to a reduction in incontinence and dyspareunia after childbirth

    Observations of DG Tauri with the Keck Interferometer

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    We present the first science results from the Keck Interferometer, a direct-detection infrared interferometer utilizing the two 10-meter Keck telescopes. The instrument and system components are briefly described. We then present observations of the T Tauri object DG Tau, which is resolved by the interferometer. The resolved component has a radius of 0.12 to 0.24 AU, depending on the assumed stellar and extended component fluxes and the model geometry used. Possible origins and implications of the resolved emission are discussed.Comment: 10 pages, 2 figures, to appear in ApJ Letter

    Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve

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    This study investigated the effects of a newly established, fully protected marine reserve on benthic habitats and two commercially valuable species of scallop in Lamlash Bay, Isle of Arran, United Kingdom. Annual dive surveys from 2010 to 2013 showed the abundance of juvenile scallops to be significantly greater within the marine reserve than outside. Generalised linear models revealed this trend to be significantly related to the greater presence of macroalgae and hydroids growing within the boundaries of the reserve. These results suggest that structurally complex habitats growing within the reserve have substantially increased spat settlement and/or survival. The density of adult king scallops declined threefold with increasing distance from the boundaries of the reserve, indicating possible evidence of spillover or reduced fishing effort directly outside and around the marine reserve. However, there was no difference in the mean density of adult scallops between the reserve and outside. Finally, the mean age, size, and reproductive and exploitable biomass of king scallops were all significantly greater within the reserve. In contrast to king scallops, the population dynamics of queen scallops (Aequipecten opercularis) fluctuated randomly over the survey period and showed little difference between the reserve and outside. Overall, this study is consistent with the hypothesis that marine reserves can encourage the recovery of seafloor habitats, which, in turn, can benefit populations of commercially exploited species, emphasising the importance of marine reserves in the ecosystem-based management of fisheries

    Protecting 30% of the planet for nature: costs, benefits, and economic implications:Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

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    Protecting 30% of the planet for nature: costs, benefits, and economic implications:Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

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    Prevalence of pre-eclampsia and adverse pregnancy outcomes in women with pre-existing cardiomyopathy: a multi-centre retrospective cohort study

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    Pre-eclampsia is associated with postnatal cardiac dysfunction; however, the nature of this relationship remains uncertain. This multicentre retrospective cohort study aimed to determine the prevalence of pre-eclampsia in women with pre-existing cardiac dysfunction (left ventricular ejection fraction < 55%) and explore the relationship between pregnancy outcome and pre-pregnancy cardiac phenotype. In this cohort of 282 pregnancies, pre-eclampsia prevalence was not significantly increased (4.6% [95% C.I 2.2–7.0%] vs. population prevalence of 4.6% [95% C.I. 2.7–8.2], p = 0.99); 12/13 women had concurrent obstetric/medical risk factors for pre-eclampsia. The prevalence of preterm pre-eclampsia (< 37 weeks) and fetal growth restriction (FGR) was increased (1.8% vs. 0.7%, p = 0.03; 15.2% vs. 5.5%, p < 0.001, respectively). Neither systolic nor diastolic function correlated with pregnancy outcome. Antenatal ß blockers (n = 116) were associated with lower birthweight Z score (adjusted difference − 0.31 [95% C.I. − 0.61 to − 0.01], p = 0.04). To conclude, this study demonstrated a modest increase in preterm pre-eclampsia and significant increase in FGR in women with pre-existing cardiac dysfunction. Our results do not necessarily support a causal relationship between cardiac dysfunction and pre-eclampsia, especially given the population’s background risk status. The mechanism underpinning the relationship between cardiac dysfunction and FGR merits further research but could be influenced by concomitant ß blocker use
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