3,200 research outputs found

    Discovery of a second locality for the narrow endemic Anthemis ismelia (Asteraceae) in NW Sicily

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    A new population of Anthemis ismelia (Asteraceae) has been discovered on Mt Pecoraro (Cinisi, NW Sicily), a limestone headland at about 14 km from Mt Gallo (Palermo), the locus classicus et unicus of this species described in 1884. Taxonomic framework, distribution update, habitat characterisation, ecology and phytosociological framework are provided, as well as meta-population numerical estimates and risk status assessment

    Improvement of the mechanical and thermal characteristics of open cell aluminum foams by the electrodeposition of Cu

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    Abstract Recently aluminum foaming has been of much interest due to its characteristics properties of light weight structure. Metallic foams are highly porous materials which present complex structure of three-dimensional open cells. This aspect causes strong limitations in mass transport due to electro-deposition technology. In this work, the electro-deposition of copper on aluminum open-cell foams substrates was developed, in order to enhance the thermal and mechanical properties of these cellular materials. The mechanical and thermal characterization of the produced samples was lead through compression and conductivity tests. On the basis of the experimental results, analytical models are proposed to predict the quantity and the quality characteristics of the coating

    Urban landscape evolution as a consequence of an invasive pest: The case of a small sicilian town

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    The Red Palm Weevil (RPW), after its accidental introduction in Italy in 2005, determined a progressive disruption of Canary palms mostly in the central and southern regions. As it is difficult to undertake the management of this pest, the possibility of substituting the killed/symptomatic palms with other ornamental trees has been recently discussed. In this context, understanding the citizens' needs about green areas can improve the management of public parks and urban greening. Involving citizens on the natural resource management using public participation processes is crucial. The case study of a small town of Sicily (Italy) was treated and the spread of this pest was monitored. Moreover, the possibility of substituting the killed palms with other ornamentals was discussed by involving a sample of the population through a direct survey aimed at detecting the preferences in respect to certain tree species (as potential substitutes of the killed palms) listed in a questionnaire administered face-to-face. The citizen's samples showed great interest in the green areas (97%) and indicated a traditional Mediterranean plant as Nerium oleander as the preferred palm substitute candidate

    A methodology for optimisation of solar dish-Stirling systems size, based on the local frequency distribution of direct normal irradiance

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    In geographical areas where direct solar irradiation levels are relatively high, concentrated solar energy systems are one of the most promising green energy technologies. Dish-Stirling systems are those that achieve the highest levels of solar-to-electric conversion efficiency, and yet they are still among the least common commercially available technologies. This paper focuses on a strategy aimed at promoting greater diffusion of dish-Stirling systems, which involves optimizing the size of the collector aperture area based on the hourly frequency distributions of beam irradiance and defining a new incentive scheme with a feed-in tariff that is variable with the installed costs of the technology. To this purpose, a new numerical model was defined and calibrated on the experimental data collected for an existing dish-Stirling plant located in Palermo (Italy). Hourly-based simulations were carried out to assess the energy performance of 6 different system configurations located on 7 sites in the central Mediterranean area using two different solar databases: Meteonorm and PVGIS. A new simplified calculation approach was also developed to simulate the dish-Stirling energy production from the hourly frequency histograms of the beam irradiance. The results reveal that an optimised dish-Stirling system can produce 70–87 MWhe/year in locations with direct irradiation varying between 2000 and 2500 kWh/(m2·year). The proposed incentive scheme would guarantee a payback time for investment in this technology of about ten years and the effect of economies of scale could lead, over the years, to a levelized cost of energy similar to that of other concentrating power systems

    Improving the Sustainability of Dairy Slurry by A Commercial Additive Treatment

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    Ammonia (NH3), methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from livestock farms contribute to negative environmental impacts such as acidification and climate change. A significant part of these emissions is produced from the decomposition of slurry in livestock facilities, during storage and treatment phases. This research aimed at evaluating the eectiveness of the additive \u201cSOP LAGOON\u201d (made of agricultural gypsum processed with proprietary technology) on (i) NH3 and Greenhouse Gas (GHG) emissions, (ii) slurry properties and N loss. Moreover, the Life Cycle Assessment (LCA) method was applied to assess the potential environmental impact associated with stored slurry treated with the additive. Six barrels were filled with 65 L of cattle slurry, of which three were used as a control while the additive was used in the other three. The results indicated that the use of the additive led to a reduction of total nitrogen, nitrates, and GHG emissions. LCA confirmed the higher environmental sustainability of the scenario with the additive for some environmental impact categories among which climate change. In conclusion, the additive has beneficial eects on both emissions and the environment, and the nitrogen present in the treated slurry could partially displace a mineral fertilizer, which can be considered an environmental credit

    Quantitative Assessment of Program Outcomes Using Longitudinal Data from the FE Exam

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    There have been many studies providing details on using results from the Fundamentals of Engineering (FE) exam as metrics for meeting ABET program outcomes1. However, implementing an FE-based set of metrics poses challenges not limited to assessing validity of results. Programs using FE-based metrics must also determine the position of the metrics in the overall assessment process. We present a method for using FE-based metrics as an integral part of the ABET program assessment process. The principle issues we address are: (1) The validity of using FE metrics for a group of graduating students when not all of them take the exam; (2) Establishing and quantifying levels of performance; and (3) Creating a trigger mechanism for taking action based upon longitudinal results. The Department of Mechanical and Biomedical Engineering at Boise State University created a process which integrates metrics from the FE results with other metrics in our loop for outcomes assessment and continuous improvement. Our process prevents us from taking inappropriate action based upon isolated negative results from the FE exam. We have used our process to make a demonstrable improvement in our curriculum. Two examples of faculty action taken due to unsatisfactory and questionable results from the FE metric before our last ABET visit are presented and discussed
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