1,720,971 research outputs found
Biofuel characteristics of chars produced from rapeseed, whitewood, and seaweed via thermal conversion technologies – Impacts of feedstocks and process conditions
Get PDFUnderstanding the suitability of different conversion technologies for different types of biomass feedstocks is crucial in delivering the full valorisation of different types of biomass feedstocks. Optimal valorisation pathways can be identified by investigating the formation of products and the most efficient application technologies of these products. This is therefore novel research reporting an extensive comparative study on the biomass processing pathways (hydrothermal conversion, pyrolysis, and torrefaction) for three distinct biomass feedstocks (Rapeseed residue, Whitewood, Seaweed–Laminaria Digitata) to optimise char formation under a wide range of processing conditions and their biofuel characteristics in the bioenergy applications. The results demonstrates that Whitewood gradually decomposes during all three conversion processes to produce chars (hydrochars/biochars) that have a lower O/C-H/C ratio as process temperature increases. The char formation from Whitewood follows the dehydration process in the Van Krevelen diagram. Char formation from Rapeseed residue and L. digitata via pyrolysis also follows a similar dehydration and demethanation pathway at higher temperatures (550 °C for Rapeseed residue and 400 °C for L. digitata). However, char formation from Rapeseed residue and L. digitata via hydrothermal conversion predominantly follows the decarboxylation pathway producing structures with a higher H/C ratio and lower O/C ratio. The intrinsic reactivity analysis of these chars showed that the temperature of initial weight loss and the onset of ignition for the raw biomass sample was shifted to a higher temperature for the chars produced by hydrothermal conversion or pyrolysis, regardless of biomass feedstocks. The chars produced from Whitewood (with hydrothermal conversion, pyrolysis and torrefaction) and Rapeseed residue (with pyrolysis) have a potential application in bioenergy production due to the significant enhancement of char products. However, the chars produced from L. digitata appear less promising for bioenergy applications due to relatively low energy yield, carbon recovery, inferior char structures and a high inherent ash content
A comprehensive analysis on the synthesis of value-added chemicals via slow pyrolysis: Valorisation of rapeseed residue, whitewood, and seaweed (Laminaria digitata)
Get PDFPyrolysis has emerged as a crucial thermochemical conversion technology in the field of biomass processing. Maximising the valorisation of biomass is an essential area of investigation, as it plays a pivotal role in understanding the economic viability and practical application of these advanced technologies. The novelty of this research is to investigate how slow pyrolysis and process interdependencies influence the synthesis of value-added products (bio-oil and biogas formation alongside biochar) from distinctly different UK-based biomass feedstocks: rapeseed residue, whitewood, and seaweed (Laminaria digitata). This research also analysed the chemical composition of these products to provide a holistic understanding of the reaction mechanisms involved in their formation. The maximum yield of bio-oil from lignocellulose-rich whitewood was due to the higher selectivity of several endothermic reactions including conversions of 5-hydroxymethylfurfural into cyclic C5-ketones and alkoxyphenols into cresols and aliphatic hydrocarbons, minimizing the biochar formation. The improvement of bio-oil yield from protein-rich seaweed and lipid-rich rapeseed residue was enabled by the formation of N-heterocyclics (e.g., via the Maillard reaction, Dieckmann cyclization, and Buchwald–Hartwig amination) and aliphatic hydrocarbons (e.g., via deamination of fatty amides and nitriles and decarboxylation of fatty acids), respectively. Meanwhile, the dealkylation and demethoxylation of alkoxyphenols and alkylphenols were responsible for the increased content of hydrocarbons in biogas. The findings provide valuable insights into the maximum valorisation of different types of UK-based biomass resources in slow pyrolysis for the production of biochars and lighter bio-oils to make pyrolysis a key process in biorefineries
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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