1,720,965 research outputs found
Environmental Performance of Semi-Aerobic Landfill by Means of Life Cycle Assessment Modeling
Full text linkThe potential impacts and the environmental performance of the semi-aerobic landfill technology were assessed through the Life Cycle Assessment (LCA) methodology. Project data that referred to a hypothetical Italian plant design were used and ISO 14040/14044 standards were applied. All the life cycle phases were considered, from landfill construction to filling, aftercare, closure and conversion for future use. All the landfill processes and the inflow of materials, energy and rainwater, and the outflow of biogas and leachate, were included in the system boundaries. The results show that the overall environmental impacts associated to semi-aerobic landfill are primarily due to the filling and aftercare phases, but the impacts related to construction and closure phases are not negligible. The contribution analysis underlines the processes with major responsibility within the environmental profile, while the normalization of results demonstrates what are the environmental categories on which the landfill impacts fall most. Important lessons emerging from this research can support practitioners and scientists in optimizing semi-aerobic landfill design and management
Environmental performance of glass foam as insulation material from waste glass with the alkali activation process
Full text linkGlass foams is an interesting option for the use of fractions of glass cullet otherwise destined to landfills. As building insulation materials, glass foams obtained by conventional processes have still some drawbacks in the purity of starting feedstock, which can be avoided by implementing an alkali activation process. Using the life cycle assessment methodology, the research analyses the potential impacts associated to the glass foam obtained from waste glass through the alkali activation in a laboratory scale plant with 'cradle to grave' perspective. The main phases included in the system boundaries are the downstream activities related to the transportation of glass waste and avoided landfill disposal, the production process to obtain the glass foam, and the upstream activities related to the transportation to potential use phase and the end of life. The life cycle environmental profile of glass foam is calculated starting from primary data integrated with the Ecoinvent database, and using the ReCiPe 2016 impact assessment method and the SimaPro software. Results demonstrate the greatest contribution on the overall environmental impacts due to the production, in which the main impacts are linked to electricity consumption for drying and firing and surfactant for the foaming. Sensitivity analyses clarify that consistent improvement in overall environmental impacts can be obtain with minimization of distances both between glass waste and production site, and between glass foam production and use; otherwise, different energy-mix and lower temperature in chemical processes have negligible effects in the environmental profile. The research reveals useful information to optimize the upcycling of glass foam production before moving on the industrialization: future investigations should involve the selection of biodegradable surfactants, from renewable sources
ENVIRONMENTAL PROFILE OF ANAEROBIC AND SEMI-AEROBIC LANDFILLS WITHIN SUSTAINABLE WASTE MANAGEMENT: AN OVERVIEW
No full textThe new perspective of circular economy accelerates the efforts to increase reuse and recycling of products and reduce the need of resources. Although the quantity of waste reaching the end-of-life has decreased, landfills can't be eliminated from the waste management systems (WMS) since the current treatment processes still produce unrecyclable materials. Anaerobic landfills have great environmental impacts due to the long-term emissions, therefore, to reach a more sustainable waste management less impacting alternatives are being implemented. Semi aerobic landfills can reduce the environmental burdens by enhancing waste stabilization with natural air flow inside the landfill body through the leachate collection pipes. The presence of aerobic areas implies biogas with less methane and leachate with lower pollutant concentrations. The research goal is to deepen the evidence that the semi-aerobic landfills are environmentally preferable to traditional anaerobic landfills, by considering the scientific information published in international peer-reviewed journals from 2000 to 2022. To obtain comprehensive answers to the research question, papers using the life cycle assessment (LCA) methodology are included in the review, with the aim of understanding what the environmental profiles of traditional and semi-aerobic landfill are when all life cycle phases are considered. The results clarify what the main contributions to environmental impacts of these two types of landfills are. The review only partially demonstrates the environmental convenience of semi-aerobic landfill. Instead, it reveals a lack of papers analyzing the comparison between different landfill technologies, suggesting new research perspectives to optimize the sustainability of final treatment solutions in WMS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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