501 research outputs found

    Effect of Environmental and Ultraviolet Degradation on the Albedo of Polyethylene Sheet Materials for Improved Energy Harvesting by Bifacial Photovoltaic Power Plants

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    Solar energy farms typically utilize monofacial photovoltaic (mPV) cells in their arrays to capture direct sunlight to produce renewable energy. However, the efficiency of these farms can be increased by 2 – 6% through the implementation of bifacial photovoltaic cells (bPV). These bPV cells function by capturing incident ultraviolet (UV) light energy that is reflected off the surface to increase its overall energy production. The amount of UV energy that is reflected is dependent on the albedo value of surface, which is a measure of energy reflectance. In this study, samples of unreinforced polyethylene (PE), scrim-reinforced polyethylene (SR-PE), and woven polyethylene (W-PE) sheeting materials were tested to determine which had the highest albedo value as well as the most resistance to environmental degradation. Samples subjected to outdoor conditions were visited on a biweekly basis to measure their albedo values using an albedometer and to record any physical changes observed in the material. Samples were also placed in an accelerated weathering chamber in a laboratory which exposed the materials to continuous UV light in intervals of 20 hours. The results from testing determined that woven PE produced a 23% higher average albedo in comparison to the other candidate PE materials. Woven PE also demonstrated lower quantitative and qualitative environmental degradation. Based on these results, woven PE was concluded to be empirically superior as a ground albedo material among the materials tested in this study

    Exploring human-nature interaction on the coastal floodplain in the ganges-brahmaputra delta through the lens of ostrom’s social-ecological systems framework

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    This study diagnoses temporal and spatial variations in the performance of different social-ecological systems (SES) in coastal floodplain management in the Ganges-Brahmaputra delta. We go beyond common pool resource management problems and address the management of local public goods. In the assessment, we consider recent developments in the framework initially developed by Elinor Ostrom. The main variables of the framework that we use are resource systems, the environment, the governance system and actors. The focal SES is defined based on guiding questions relating to the definition of the key problem, system boundaries, and action situations. According to our results, the performance of resource systems and the environment deteriorated in 1960–79 compared to the performance prior to 1960. The condition reached a low point during 1980–1999 but improved slightly after 1999. The horizontal network structure of local governance was active until 1960. Due to the introduction of the ‘tidal river management’ approach in the 90 s, the performance of the resource system and the environment has slightly improved, as has the involvement of government and non-government organizations. Our results also show that overall SES performance is comparatively bette

    Water governance in a comparative perspective: From IWRM to a 'nexus' approach?

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    Nexus thinking, in the form of integrating water security with agriculture, energy and climate concerns, is normatively argued to help better transition societies towards greener economies and the wider goal of sustainable development. Yet several issues emerge from the current debate surrounding this concept, namely the extent to which such conceptualisations are genuinely novel, whether they complement (or are replacing) existing environmental governance approaches and how - if deemed normatively desirable - the nexus can be enhanced in national contexts. This paper therefore reviews the burgeoning nexus literature to determine some common indicative criteria before examining its implementation in practice vis-à-vis more established integrated water resources management (IWRM) models. Evidence from two divergent national contexts, the UK and Bangladesh, suggests that the nexus has not usurped IWRM, while integration between water, energy, climate and agricultural policy objectives is generally limited. Scope for greater merging of nexus thinking within IWRM is then discussed

    Exploring institutional structures for Tidal River Management in the Ganges-Brahmaputra Delta in Bangladesh

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    Tidal River Management (TRM) is a local adaptation strategy for coastal floodplains in the Ganges-Brahmaputra Delta in Bangladesh. TRM involves the periodic opening and closing of embankments to accelerate land accretion (or reclamation) in a floodplain. Although the approach is considered a promising adaptation strategy, there have been both positive and negative outcomes from recent TRM implementation. The aim of this study is consequently to explore the institutional (community, rules-in-use, and also biophysical) factors influencing successes and failures of TRM implementation for managing common-pool resources, as a basis for making recommendations on future institutional design. The Institutional Analysis and Development (IAD) framework, first developed by Ostrom (2010) and revised by Bisaro and Hinkel (2016), is therefore used to conduct comparative analysis of TRM institutional effectiveness in three Delta floodplains or beels: one led by a local community and the other two by national authorities. Our research employs a mixed method approach involving focus group discussions, stakeholder interviews, site visits, along with secondary literature analysis. The results of this assessment provide insights into coastal adaptation governance that could inform TRM implementation in Bangladesh and other similar contexts worldwide

    Sustainable coastal social-ecological systems: how do we define “coastal”?

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    Coastal social-ecological systems (SES) are home to over 500 million people and one of the most productive and diverse ecosystems in the world. In recent years, coastal SES are experiencing severe threat from an increasing population, resource exploitation, and global environmental change (e.g. climate change), which have devastating societal impacts in coastal areas. Despite several global, national, and local initiatives, there is a growing consensus that coastal resources are depleting and increasing conflicts in coastal areas. Recognizing the global call to understand social–ecological interactions for implementing development practices, this special issue features a suite (seven) of articles advancing the understanding of the sustainability of social and ecological interactions within coastal areas through theoretical SES approaches and related analytical methods. In this editorial of this special issue, we also argued that coastal area needs to define from SES perspectives, which have received less attention compared to ecological and social perspectives. We hope that this special issue will stimulate the debate and further thinking of how coastal SES can be managed sustainably by conceptualizing and understanding the complex dynamics (interaction, feedback) of SES

    Climate change impacts in agricultural communities in rural areas of coastal bangladesh: A tale of many stories

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    This paper identifies and analyses climate change impacts, their cascading consequences and the livelihood implications of these impacts on smallholder agricultural communities of coastal Bangladesh. Six physically and socio-economically vulnerable communities of south-western coastal regions were studied. Primary data was collected through focus group discussions, a seasonal calendar, and historical transect analysis. Three orders of impacts of climate change on smallholder farmers are identified and described. The first order impacts involve increasing erosion of the capacity of local communities to mitigate vulnerability to climate change impacts. This situation led to the second order impacts, which significantly transformed the agricultural landscape and production patterns. The cumulative effects of the first and second order impacts sparked the third order impacts in the form of worsening community livelihood assets and conditions. The findings of this paper can contribute to the formulation of sustainable adaptation policies and programs to manage the vulnerability of local communities to climate change impacts in the country effectively

    Moving Least-Squares Reconstruction of Large Models with GPUs

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    Modern laser range scanning campaigns produce extremely large point clouds, and reconstructing a triangulated surface thus requires both out-of-core techniques and significant computational power. We present a GPU-accelerated implementation of the Moving Least Squares (MLS) surface reconstruction technique. While several previous out-of-core approaches use a sweep-plane approach, we subdivide the space into cubic regions that are processed independently. This independence allows the algorithm to be parallelized using multiple GPUs, either in a single machine or a cluster. It also allows data sets with billions of point samples to be processed on a standard desktop PC. We show that our implementation is an order of magnitude faster than a CPU-based implementation when using a single GPU, and scales well to 8 GPUs

    Using Poll Sheets and Computer Vision as an Inexpensive Alternative to Clickers

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    Classroom Response Systems, colloquially known as Click- ers after the predominant hand-held input device, are widely used because they allow students to respond in class to questions posed by the lecturer. This improves active learning and interaction in large classes—students are more involved, and lecturers can assess understanding and even take remedial action. Unfortunately, Clicker systems are relatively expensive, particularly in a developing-world con- text. They typically cost 200700forabasestationand200–700 for a base station and 30–50 per Clicker. In this paper we present an inexpensive alternative to Clickers. Poll sheets with coloured blocks printed on a white background are held up by the students and a camera- phone is used in panoramic mode to photograph the class. This image is then processed using computer vision to count and classify the students’ responses. While the 85% recognition rate we achieve is certainly not as accurate as Clickers, this approach nevertheless has many of the same benefits for active learning at a fraction of the cost: $0.20 per poll sheet, assuming a laptop and camera-phone are already available

    Flood loss models and risk analysis for private households in can Tho City, Vietnam

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    Vietnam has a long history and experience with floods. Flood risk is expected to increase further due to climatic, land use and other global changes. Can Tho City, the cultural and economic center of the Mekong delta in Vietnam, is at high risk of flooding. To improve flood risk analyses for Vietnam, this study presents novel multi-variable flood loss models for residential buildings and contents and demonstrates their application in a flood risk assessment for the inner city of Can Tho. Cross-validation reveals that decision tree based loss models using the three input variables water depth, flood duration and floor space of building are more appropriate for estimating building and contents loss in comparison with depth-damage functions. The flood risk assessment reveals a median expected annual flood damage to private households of US$3340 thousand for the inner city of Can Tho. This is approximately 2.5%of the total annual income of households in the study area. For damage reduction improved flood risk management is required for the Mekong Delta, based on reliable damage and risk analyses

    Международно-правовое регулирование труда трудящихся мигрантов на универсальном уровне

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    Раскрываются особенности правовых актов МОТ, которые отличают данные акты от документов других специализированных учреждений ООН и международных договоров в области прав человека, принятых Генеральной Ассамблеей ООН.Analyse, it is necessary to open in brief at first features of legal acts of ILO, which distinguish the given acts from documents of other specialised institutions of the United Nations and the international contracts in human rights sphere accepted by the United Nations General Assembl
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