Energy recovery from marine plastic waste after the collection and pretreatment of refuse plastic fuel (RPF) offers a practical measure to prevent the formation of microplastics, which pose a threat to marine biota and human health. This study investigated the fixed-bed combustion of RPF by visual observation and detailed measurement of the key combustion parameters. Unlike the fluff form, densely compacted RPF particles were not suitable for dedicated combustion in a fixed bed reactor because they melted and subsequently blocked the air passages. However, cofiring with 20 wt.% or a larger amount of wood pellets (WP) successfully stabilized the flame propagation because the WP particles secured the air passages. For the RPF-WP blend (6:4), an airflow rate of 800 kg/m2h was found to be ideal for maximizing the burning rate (148 kg/m2h) or grate heat release rate (4347 MJ/m2h). The flame temperatures above 1100 °C accelerated the downward propagation of the flame front to 0.389 m/h. The corresponding equivalence ratio was 1.73, indicating that additional air was required to complete the oxidation of the fuel-rich gas released from the bed. The combustion parameters derived in this study are useful for guiding the primary design variables of industrial-scale grate furnaces.
The objective of this research project is to develop and validate a method for using satellite images and digital geospatial data to map the distribution of southern pine beetle (SPB) habitats across the pinelands of east Texas. Our approach builds on a work that used photo interpretation and discriminant analysis to identify and evaluate environmental conditions suitable for SPB infestation. Because current implementations of Billings and Bryant’s method by the Texas Forest Service (TFS) use manual photo interpretation, they are relatively costly, labor intensive, and require sampling. Satellite imagery and geographic information system (GIS) technology present potential means to reduce operational costs and improve accuracy. Here we report the principal results of our work in a pilot area of east Texas, specifically: (1) development and integration of satellite and digital inputs into the Billings and Bryant model, (2) accuracy assessment of model inputs, (3) validation of the model adaptation through comparison of satellite-derived SPB hazard maps to operational maps produced by TFS, and (4) revalidation of the model through comparison of satellite-derived SPB hazard maps to known locations of SPB infestations. Collectively, the results point to the considerable potential of satellite imagery and automated analysis techniques to produce timely, accurate, and cost-effective maps of SPB hazard at the landscape level.
As United Nation (UN) declared 2010 to be the International Year of Biodiversity, the biodiversity issue has gained much attention since the issue of climate changes. Also, related researches for protecting and conserving the biodiversity are accompanied in the world. In this study, National Ecology Information is obtained from Ministry of Environment and Korea Forest Service and is utilized to valuate biodiversity and ecosystem services in Pyeongchang, Kangwon-do in Korea. For this, they are categorized into direct- or indirect-use value and nonuse value. Research results show that the biodiversity and ecosystem services in Pyeongchang are assessed as 2 trillion and 460 billion won. From this research, we evaluate the economic value of biodiversity and ecosystem services, and also suggest the possibility to utilize them as basic information for a decision making to establish the biodiversity protection plan.
In high-rise buildings, it is necessary to measure the structural responses to wind load. GPS is solution to measure the structural responses of high-rise buildings. However, the precision of the data was relatively low due to the relatively low reception frequency, and the measurement precision was not assessed with respect to the GPS reception frequency. In this study, to assess the precision of GPS measurement with respect to the reception frequency, we applied the widely used GPS reception methods known as the VRS method and the relative positioning method and evaluated the level of accuracy at GPS reception frequencies ranging from 5Hz to 20Hz. To do this, we built a multi-degree-of-freedom structure and assessed the GPS measurement precision by measuring the displacement at the top floor of the structure during free vibration.
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