1,937 research outputs found

    Air quality implications of developing the United Kingdom’s unconventional petroleum resources, with a focus on geological drilling and other analogous environments

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    Background & Aims: There are grave concerns that Unconventional Natural Gas (UNG) developments may severely impact air quality in the UK. To address these concerns, the thesis researches the two most significant risk-assessed hazards (i.e. drilling mud and combustion-related activities) by developing methods to identify physical phenomenon and source characteristics of key air pollutants - Particulate Matter (PM), Black Carbon (BC) and Nitrogen Oxides (NOX). Methods: The methods include personal air quality monitoring and statistical computing, including two pilot methods tested in Glasgow, before statistical computing is tested on data from the Preston New Road UNG site. Results: Statistical computing allows for long-term averaging and spatial temporal evaluation of industrial sites such as the Preston New Road drilling site, and when ratios (e.g. BC: NOX) are used, can detect discrete industrial and vehicular sources. Lastly, a review of PM on drilling rigs indicated high occupational exposures, which could cause respiratory disease, the chemicals within oil-based mad formulations were also found to pose a significant respiratory hazard. Conclusions: Air pollution from UNG at the Preston New Road site was less significant than conjecture and was less impactful than a nearby dairy farm. However, drilling mud exposures may present a high-risk occupational respiratory hazard to workers on modern onshore drilling rigs both from the quantity of airborne PM and from hazardous chemical dust. The developed methods also offer improved and cost-effective methods for source evaluation studies which could be implemented within most air pollution microenvironments.Background & Aims: There are grave concerns that Unconventional Natural Gas (UNG) developments may severely impact air quality in the UK. To address these concerns, the thesis researches the two most significant risk-assessed hazards (i.e. drilling mud and combustion-related activities) by developing methods to identify physical phenomenon and source characteristics of key air pollutants - Particulate Matter (PM), Black Carbon (BC) and Nitrogen Oxides (NOX). Methods: The methods include personal air quality monitoring and statistical computing, including two pilot methods tested in Glasgow, before statistical computing is tested on data from the Preston New Road UNG site. Results: Statistical computing allows for long-term averaging and spatial temporal evaluation of industrial sites such as the Preston New Road drilling site, and when ratios (e.g. BC: NOX) are used, can detect discrete industrial and vehicular sources. Lastly, a review of PM on drilling rigs indicated high occupational exposures, which could cause respiratory disease, the chemicals within oil-based mad formulations were also found to pose a significant respiratory hazard. Conclusions: Air pollution from UNG at the Preston New Road site was less significant than conjecture and was less impactful than a nearby dairy farm. However, drilling mud exposures may present a high-risk occupational respiratory hazard to workers on modern onshore drilling rigs both from the quantity of airborne PM and from hazardous chemical dust. The developed methods also offer improved and cost-effective methods for source evaluation studies which could be implemented within most air pollution microenvironments

    Grapheme coding in L2:how do L2 learners process new graphemes?

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    International audienceGrapheme coding was examined in French Grade 6 and Grade 8 children and adults who learned English as a second language (L2). In Experiments 1 and 2, three conditions were compared in a letter detection task in L2: (1) simple grapheme (i.e., detect “a” in black); (2) complex language-shared grapheme (i.e., “a” in brain) and (3) complex L2-specific grapheme (i.e., “a” in beach). The data indicated that graphemes in L2 words were functional sub-lexical orthographic units for these L2 learners. Moreover, L2-specific graphemes took longer to process than language-shared complex graphemes. Using the same task, Experiment 3 examined phonological influences by manipulating the cross-language congruency of grapheme-to-phoneme mappings (detect “a” in have [congruent] vs. take [incongruent]). The outcome of this study offers preliminary evidence of graphemic coding during L2 word recognition both at the orthographic and the orthography-to-phonology mapping levels

    Environmental Virtual Observatories (EVOs): Prospects for knowledge co-creation and resilience in the Information Age

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    Developments in technologies are shaping information access globally. This presents opportunities and challenges for understanding the role of new technologies in sustainability research. This article focuses on a suite of technologies termed Environmental Virtual Observatories (EVOs) developed for communicating observations and simulation of environmental processes. A strength of EVOs is that they are open and decentralised, thus democratising flow and ownership of information between multiple actors. However, EVOs are discussed rarely beyond their technical aspects. By evaluating the evolution of EVOs, we illustrate why it is timely to engage with policy and societal aspects as well. While first generation EVOs are primed for scientists, second generation EVOs can have broader implications for knowledge co-creation and resilience through their participatory design

    From dot to ring: the role of friction on the deposition pattern of a drying colloidal suspension droplet

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    The deposition of particles on a substrate by drying a colloidal suspension droplet is at the core of applications ranging from traditional printing on paper to printable electronics or photovoltaic devices. The self-pinning induced by the accumulation of particles at the contact line plays an important role in the formation of the deposition. In this paper, we investigate both numerically and theoretically, the effect of friction between the particles and the substrate on the deposition pattern. Without friction, the contact line shows a stick-slip behaviour and a dot-like deposit is left after the droplet is evaporated. By increasing the friction force, we observe a transition from a dot-like to a ring-like deposit. We propose a theoretical model to predict the effective radius of the particle deposition as a function of the friction force. Our theoretical model predicts a critical friction force when the self-pinning happens and the effective radius of deposit increases with increasing friction force, confirmed by our simulation results. Our results can find implications for developing active control strategies for the deposition of drying droplets.Comment: 11 pages, 10 figure
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