1,720,970 research outputs found
Energy recovery from plastic and biomass waste by means of fluidized bed gasification: A life cycle inventory model
No full textThe study provides for the first time a life cycle inventory model for the fluidized bed gasification of wastes, based on a large amount of high-quality data. All of them have been obtained from a pilot scale fluidized bed gasifier, fed with ten types of waste and biomass, under a wide range of operating conditions. The model refers to commercial scale gasifiers having a “thermal configuration”, where the generated syngas is immediately burned downstream of the reactor. Key relationships between process- and waste-specific parameters have been defined. The model quantifies the main inputs and outputs of the gasification process (emissions, energy recovery, ash disposal, resource consumptions), providing high-quality data that could contribute to improve life cycle assessment modelling of waste gasification. Finally, some case studies have been implemented in the EASETECH software to illustrate the model applicability, evaluate the role of main parameters, and compare the environmental performances of gasification power units with that of the European electricity mix. The performances appear highly affected by metal contents in the waste-derived fuels, while the model results to a limited extent are sensitive to the equivalence ratio and the net electrical efficiency of the energy conversion
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
Process-oriented life cycle assessment modelling of (bio)energy technologies
No full textIn the endeavour of reducing greenhouse gas emissions (GHGs) mainly due to human activities, reaching carbon neutrality by 2050 and maintaining globalmean temperatures below political targets, new and efficient solutions are needed. Bio-based energy, or bioenergy, plays an important role in a worldwhere the majority of GHG emissions are from energy. Bioenergy technologies convert biomass to energy. Using biomass as residues from human activitiesor organic fraction of waste to produce bioenergy has several advantages: i) providing solutions to waste management, ii) promoting material recirculationtoward bio-based energy, iii) supplying fossil energy demand, and avoiding for example land use changes of using crops for energy. Bioenergy technologieswill contribute to a non-fossil and more sustainable society by transforming bioresources into energy. There are a wide range of challenges associated withthis transition such as availability of bioresources, spatial distribution of bioresources, and various conversion technologies. The selection of the environmentally most appropriate technologies to valorise the specific bioresources is also a challenge. Bioresource properties, conversion yields, outputs and rejects, as well as process performance for the bioresources in question need to be systematically evaluated and addressed by assessing the environmental impacts. Life cycle assessment (LCA) is a standardised method for assessing the environmental performance of technologies and systems. There is a need to expand and improve the modelling of bioenergy technologies, beyond black-box process models in conventional LCA modelling tools. Black-box models typically ignore the links between feedstock characteristics and process outputs. For example, adapting the inventory of a technology to reproduce another one. As such, these models do not reflect changes of operational conditions or conversion efficiencies in a process pathway. Thereby, the reproducibility of a technology and adaptability of the model to specific case studies are limited. The consequence is lack of transparency and limited flexibility from a modelling perspective. The main goal of this PhD project was to provide a process-oriented LCA modelling framework and apply this to a range of selected bioenergy technologies (e.g. anaerobic digestion, gasification, and upgrading units) and systems of technologies. The framework allowed quantitative and parametrized physical chemical input-output relationships. The generalised principles for processoriented LCA modelling were developed and implemented into the modelling framework, EASETECH+, as an extension to the existing LCA model, EASETECH. A range of illustrative examples was used to explain and highlight key features and LCA modelling approaches associated with the framework. The feasibility of the process-oriented modelling approach was demonstrated upon implementation of technology models within the LCA model EASETECH, including use of all novel operators and functions for model definition in EASETECH+. The new process-oriented framework facilitates LCA modelling of a wide range of conversion processes relevant for bioenergy technologies, including material recirculation, multiple outputs, conditional sequence flows, linear and non-linear responses in conversion pathways. Based on the PhD, a range of novel process-oriented technology models were implemented into EASETECH as ready-to-use technology templates for newcase-studies, including: i) biorefinery, ii) anaerobic digestion, iii) thermal gasification; iv) bio-based methane upgrading.The consequences of subdividing a technology into unit-processes was givenby a second generation biorefinery, managing bioresources with high cellulose, hemicellulose, and lignin content. Pretreatment, hydrolysis, fermentation and distillation, and recovery were the four unit processes identified. Input -output relationships with parameters (e.g. conversion efficiency) were included in each unit-process. Changes of parameters within unit-processes had changes on the mass, substance, energy balance, thus on the intermediate outputs (e.g. simple sugars), final outputs (e.g. ethanol), and environmental performance. For example, increasing the conversion efficiency of cellulose increased the production of sugars and ethanol causing more global warming savings. A systematic approach accommodating the process-oriented modelling principles was developed and applied on a regional case for bio-based methane supply in the French region of Occitania. This allowed finding environmentallyefficient import/export strategies to supply the gas demand of a region considering:i) availability and properties of bioresources on the region, ii) biological and thermochemical degradation of bioresources, through anaerobic digestionand gasification (both with upgrading), iii) environmental performance of conversion pathways and impacts (induced and avoided) by the current management of the involved bioresources. This can support practical actions toward local bioeconomy and climate goals.<br/
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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