271 research outputs found

    Determination of phosphorus in natural waters: A historical review.

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    The aim of this paper is to introduce a virtual special issue that reviews the development of analytical approaches to the determination of phosphorus species in natural waters. The focus is on sampling and sample treatment, analytical methods and quality assurance of the data. The export of phosphorus from anthropogenic activities (from diffuse and point sources) can result in increased primary production and eutrophication, and potentially the seasonal development of toxic algal blooms, which can significantly impact on water quality. Therefore the quantification of phosphorus species in natural waters provides important baseline data for studying aquatic phosphorus biogeochemistry, assessing ecosystem health and monitoring compliance with legislation

    IN-SHOE PLANTAR PRESSURE MEASUREMENTS DURING GOLF SWING PERFORMANCE WEARING METAL AND ALTERNATIVE SPIKED GOLF SHOES

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    In-shoe plantar pressures were assessed when two different golf shoes were worn. One shoe design incorporated 7 metal spikes and the other 7 alternative spikes. Eighteen male golfers (mean handicap ±SD: 12.4 ± 7.8) played 5 shots with a 7 iron while wearing each shoe on a natural grass surface. Pressures in 9 standardised foot regions were analysed to yield maximal, average and ball impact values. The greatest pressures were at the lateral regions of the front-foot from the point of ball impact when wearing the metal spike shoes. Significantly greater maximal pressures occurred when wearing the metal spike shoe (front foot: lateral 114 kPa; back foot: lateral heel 40 kPa, medial central 63 kPa;

    The molybdenum blue reaction for the determination of orthophosphate revisited: Opening the black box

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    The molybdenum blue reaction, used predominantly for the determination of orthophosphate in environmental waters, has been perpetually modified and re-optimised over the years, but this important reaction in analytical chemistry is usually treated as something of a 'black box' in the analytical literature. A large number of papers describe a wide variety of reaction conditions and apparently different products (as determined by UV–visible spectroscopy) but a discussion of the chemistry underlying this behaviour is often addressed superficially or not at all. This review aims to rationalise the findings of the many 'optimised' molybdenum blue methods in the literature, mainly for environmental waters, in terms of the underlying polyoxometallate chemistry and offers suggestions for the further enhancement of this time-honoured analytical reaction

    Cadmium contamination of agricultural soils and crops resulting from sphalerite weathering.

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    The biogeochemistry and bioavailability of cadmium, released during sphalerite weathering in soils, were investigated under contrasting agricultural scenarios to assess health risks associated with sphalerite dust transport to productive soils from mining. Laboratory experiments (365 d) on temperate and sub-tropical soils amended with sphalerite (<63 μm, 0.92 wt.% Cd) showed continuous, slow dissolution (0.6-1.2% y(-1)). Wheat grown in spiked temperate soil accumulated ≈38% (29 μmol kg(-1)) of the liberated Cd, exceeding food safety limits. In contrast, rice grown in flooded sub-tropical soil accumulated far less Cd (0.60 μmol kg(-1)) due to neutral soil pH and Cd bioavailability was possibly also controlled by secondary sulfide formation. The results demonstrate long-term release of Cd to soil porewaters during sphalerite weathering. Under oxic conditions, Cd may be sufficiently bioavailable to contaminate crops destined for human consumption; however flooded rice production limits the impact of sphalerite contamination

    A highly attenuating and frequency tailorable annular hole phononic crystal for surface acoustic waves

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.Surface acoustic wave (SAW) devices are widely used for signal processing, sensing and increasingly for lab-on-a-chip applications. Phononic crystals can control the propagation of SAW, analogous to photonic crystals, enabling components such as waveguides and cavities. Here we present an approach for the realisation of robust, tailorable SAW phononic crystals, based on annular holes patterned in a SAW substrate. Using simulations and experiments, we show that this geometry supports local resonances which create highly attenuating phononic bandgaps at frequencies with negligible coupling of SAWs into other modes, even for relatively shallow features. The enormous bandgap attenuation is up to an order-of-magnitude larger than that achieved with a pillar phononic crystal of the same size, enabling effective phononic crystals to be made up of smaller numbers of elements. This work transforms the ability to exploit phononic crystals for developing novel SAW device concepts, mirroring contemporary progress in photonic crystals.The control and manipulation of propagating sound waves on a surface has applications in on-chip signal processing and sensing. Here, Ash et al. deviate from standard designs and fabricate frequency tailorable phononic crystals with an order-of-magnitude increase in attenuation.B.J.A. acknowledges funding from the EPSRC Centre for Doctoral Training in Metamaterials, grant number EP/L015331/1

    THE EFFECT OF BUNGEE TENSION ON POWER PROFILING IN KAYAK ERGOMETRY

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    In water sports, where accurate biomechanical measurement in situ is difficult, ergometers are frequently used to test athletes. Many kayak ergometer designs involve a bungee to assist in returning the athlete/paddle to the correct position for the next stroke. The study’s aim was to investigate the effect of bungee tension on the ergometermeasured maximal power-velocity profile of three experienced male kayak athletes. Bungee tension influenced the power-velocity profile, reducing peak power measured by up to 328.4 W from optimal to least optimal tension. Athlete’s anecdotally preferred feel tensions may be optimal, thus these tensions should be considered in investigating power-related factors

    A portable battery-powered flow injection monitor for the in situ analysis of nitrate in natural waters

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    The design and performance of a portable, automated flow injection (FI)-based photometric monitor are described. The system is controlled by an in-house microcomputer system that enables the monitor (including a solid state detector) to operate from a 12 V battery supply. The monitor uses the cadmium reduction/diazotization method to analyse for nitrate with a linear range of 0 to 12 mg l-1 and a limit of detection of 0.05 mg l-1 (NO3-N). The hardware and software design, monitor performance and results obtained during unattended operation are presented

    On-line analyte preconcentration with atomic spectrometric detection

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    Pre-concentration of analytes, or matrix removal to overcome interferences using mini- or micro-columns of exchange media prior to atomic spectrometric detection is becoming increasingly more common. This paper is a review of some of the more recent applications of chelating, ion exchange and other resins and gels that have been used to accomplish this

    Climate change education for universities: a conceptual framework from an international study

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    The role of universities in climate change education (CCE) is of great importance if the scientific, social, environmental and political challenges the world faces are to be met. Future leaders must make decisions from an informed position and the public will need to embed climate change mitigation tools into their work and private life. It is therefore essential to understand the range of CCE strategies being taken globally by Higher Education Institutions (HEIs) and to explore and analyse the ways that HEIs could better address this challenge. Consistent with this research need, this paper offers an analysis of the extent to which HEIs in 45 countries approach CCE and provides a conceptual framework for exploring how HEIs are embedding CCE into their curricula. In addition to the specialist approach (where students choose to study a degree to become experts in climate change adaptation and mitigation tools), the CCE framework developed identifies and highlights three other approaches HEIs can deploy to embed CCE: Piggybacking, mainstreaming and connecting (transdisciplinary). Using data gathered in an explorative international survey involving participants working across academic and senior management, this paper illustrates the different approaches taken and analyses practical examples of current CCE practice from across the world. Responses from 212 university staff from 45 countries indicated that CCE was highly variable – no clear pattern was identified at the country level, with CCE approaches varying significantly, even within individual HEIs. This plurality highlights the wide range of ideas and examples being shared and used by institutions in very different countries and contexts, and underlines the importance of the independence and autonomy of HEIs so that they can choose the right CCE approaches for them. To highlight the breadth and variety of approaches that were uncovered by our survey, the paper offers a range of examples illustrating how climate change education may be embedded in a higher education context, some of which could be replicated in HEIs across the world. The conceptualisation of CCE and the examples given in this paper are valuable for anyone who is thinking about strategies for embedding more climate education in the higher education curriculum
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