59,494 research outputs found

    Conceptual models of Witbank coalfield, South Africa : Earth observation for monitoring and observing environmental and societal impacts of mineral resources Exploration and Exploitation, CEC FP7 Project EO-MINERS, Deliverable D3.1-2

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    This report presents the work undertaken as part of the EO MINERS WP3 - project task 3.1. “Site Specific Available Data Collection” and develops a conceptual site model (CSM) for the Witbank coalfield, South Africa and for Bank Colliery, South Africa which has been selected to demonstrate the automated time-lapse electrical resistivity monitoring (ALERT) system of a leachate plume. The report presents the available information regarding known apparent environmental impacts. This information is derived from a literature review and from the findings of surveys conducted as part of work package WP1. Additionally the principal socio-economic impacts defined by WP1 have been presented. It goes on to consider the environmental factors that influence the transport of contaminants from the source to the exposed individuals or environmental receptors, through identified potential exposure pathways, describing the source- pathway-receptor interactions through two conceptual site models (CSMs), one for the Witbank Coal Mining region and the other for Bank Colliery. A CSM for the socio-economic impacts has also been attempted. Examining the CSM results in the identification of data gaps and information needed for a full environmental assessment of mining in Witbank and provides the rational for EO selection. Present and past coal mining in Witbank is associated with a number of environmental problems, including: acid mine drainage (AMD) derived from the oxidation of pyrite in the coal, specific contaminants including potentially harmful metals and arsenic (which occur in the mining environment and in dust associated with both the operation of the mines and the transport of the coal) and ground gases that are both naturally occurring and a consequence of self-combustion of the coal and waste dumps. A wide range of ecological and socio-economic impacts result from these impacts, including the impacts on land value and agriculture. Additional problems include ground subsidence due to pillar collapse, which has further consequences on the migration of AMD and self combustion. The CSMs have been used to identify the key direct or indirect indicators of mining impacts and an assessment of the potential to monitor these using Earth Observatory (EO) assessments has been made. The majority of the indicators lend themselves to EO assessment in one form or another (Table 7)

    Negative Link Prediction in Social Media

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    Signed network analysis has attracted increasing attention in recent years. This is in part because research on signed network analysis suggests that negative links have added value in the analytical process. A major impediment in their effective use is that most social media sites do not enable users to specify them explicitly. In other words, a gap exists between the importance of negative links and their availability in real data sets. Therefore, it is natural to explore whether one can predict negative links automatically from the commonly available social network data. In this paper, we investigate the novel problem of negative link prediction with only positive links and content-centric interactions in social media. We make a number of important observations about negative links, and propose a principled framework NeLP, which can exploit positive links and content-centric interactions to predict negative links. Our experimental results on real-world social networks demonstrate that the proposed NeLP framework can accurately predict negative links with positive links and content-centric interactions. Our detailed experiments also illustrate the relative importance of various factors to the effectiveness of the proposed framework

    The function of remote sensing in support of environmental policy

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    Limited awareness of environmental remote sensing’s potential ability to support environmental policy development constrains the technology’s utilization. This paper reviews the potential of earth observation from the perspective of environmental policy. A literature review of “remote sensing and policy” revealed that while the number of publications in this field increased almost twice as rapidly as that of remote sensing literature as a whole (15.3 versus 8.8% yr−1), there is apparently little academic interest in the societal contribution of environmental remote sensing. This is because none of the more than 300 peer reviewed papers described actual policy support. This paper describes and discusses the potential, actual support, and limitations of earth observation with respect to supporting the various stages of environmental policy development. Examples are given of the use of remote sensing in problem identification and policy formulation, policy implementation, and policy control and evaluation. While initially, remote sensing contributed primarily to the identification of environmental problems and policy implementation, more recently, interest expanded to applications in policy control and evaluation. The paper concludes that the potential of earth observation to control and evaluate, and thus assess the efficiency and effectiveness of policy, offers the possibility of strengthening governance

    Safety culture in defence explosive ordnance: developing a safety climate measure

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    It is increasingly recognised within high-consequence industries that a positive safety culture is strongly linked to various safety outcomes and performance indicators. Explosive ordnance (EO) is an area that demands a high level of safety culture, indeed it is a reputational and operational necessity. This paper introduces a measure of safety climate tailored to the EO domain. The paper describes the background to the study, the development of items, and the subsequent factorial validation of scales on the basis of a sample of 272 EO personnel. The factor structure that emerged was very similar to the postulated structure of 14 climate dimensions. These 14 dimensions were shown to represent three meta-themes in the data: Safety Awareness and Responsibility (8 subscales), Safety Resources issues (3 subscales), and Safety System issues (3 subscales). The authors are confident that the EO Safety Survey is a valid, reliable and powerful tool that will support the goal of holistic reform of the EO domain. The EO Safety Survey will inform and enable tailored safety intervention efforts, improved compliance monitoring, and benchmarking studies that, collectively, will enhance the management of the human factors issues that impact on EO work

    Overcoming challenges in the classification of deep geothermal potential

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    The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed
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