1,721,010 research outputs found
An innovative ‘sea-thermal’ synergetic biorefinery for biofuel production: Co-valorization of lignocellulosic and algal biomasses using seawater under hydrothermal conditions
No full text8 figures, 2 tables.-- Supplementary information available.This study explores the co-hydrothermal treatment (co-HTT) of almond hulls and Chlorella Vulgaris using seawater as an alternative HTT medium. The influence of the feedstock (individual biomass and all the possible binary mixtures) was systematically evaluated under different conditions (reaction temperatures and times). The feedstock mixture and hydrothermal conditions significantly influenced the overall product distribution: gas (1–5%), hydrochar (6–56%), biocrude (6–55%), and aqueous fraction (33–52%), along with the most representative physicochemical and fuel properties of these products. Notably, the biocrude had a calorific value of 24–31 MJ/kg, whereas the hydrochar shifted between 3 and 26 MJ/kg. The degradation of abundant polysaccharides in almond hulls produced acidic species, promoting the degradation of proteins to N-containing species in biocrude. The synergies between microalgae and almond hulls favored the deamination of amino acid and repolymerization of formed monomers. Process optimization revealed that the best biocrude production (59% yield and HHV = 28 MJ/kg) was obtained by treating C. Vulgaris at 268 °C for 180 min. Contrarily, the HTT of almond hulls under optimum processing conditions (300 °C and 112 min) also produced an energy-dense biocrude (29 MJ/kg) but with a much lesser yield (16%). However, such a low biocrude production can be synergistically increased up to 33 %, maintaining the HHV (31 MJ/kg), including up to 61 wt% of C.Vulgaris into the feedstock, with a feedstock energy recovery of 75%. Holistically, the co-HTT of 40 wt% C. Vulgaris and 60 wt% almond hulls at 300 °C for 180 min produced energy-dense liquid (23% yield and HHV = 32 MJ/kg) and solid (29% yield and HHV = 25 MJ/kg) biofuels simultaneously, with a feedstock energy recovery of 80%. Given these excellent prospects, this strategy provides timely and new insights into developing synergetic strategies to utilize microalgal and lignocellulosic biomasses more efficiently, paving the way toward developing holistic and unseasonal biorefinery processes.This work was funded by MCIN/AEI/10.13039/501100011033 (I + D + i project PID2020-115053RB-I00) and by the Aragón Government (Research Group Reference T06-23R). This work was also financially supported by the National Natural Science Foundation of China (No. 21536007), the 111 project (B17030), and the Beijing Nova Program (Z211100002121085). Yingdong Zhou acknowledges the support from the China Scholarship Council (CSC No. 202006240156). Javier Remón is grateful to the Spanish Ministry of Science, Innovation and Universities for the Juan de la Cierva (JdC) fellowship (Grant Number IJC2018-037110-I) and thanks MCIN/AEI/10.13039/501100011033 and the European Union « NextGenerationEU»/PRTR » for the Ramón y Cajal Fellowship (RYC2021-033368-I) awarded, and the Aragón Government (Research Group Reference T22_23R) for providing frame support.Peer reviewe
Toward developing more sustainable marine biorefineries: A novel ‘sea-thermal’ process for biofuels production from microalgae
No full text5 figures, 4 tables.-- Supplementary information available.This work explores the ‘sea-thermal’ treatment of the aquatic protein-rich microalga Chlorella Vulgaris to produce energy-dense biofuels and value-added, nitrogen-rich liquid products. The impact of the processing conditions (temperature, 200–300 °C; time, 20–180 min) and reaction medium (seawater/(deionized water + seawater) ratio, 0–100 wt%) on the yields and properties of these products has been addressed using a two-level, three-factor (23) Box-Wilson Central Composite, Face Centered (CCF, α: ±1) design. These processing parameters ruled the distribution of the overall reaction products, including gas (1–5 %), biocrude (17–57 %), aqueous product (32–47 %) and hydrochar (3–45 %), and the fuel and chemical properties of these fractions. The calorific values of the hydrochar and biocrude ranged from 2 to 25 MJ/kg and 23 to 32 MJ/kg, respectively. Using low temperatures and/or short reaction times favored biocrude formation, while higher temperatures and/or more prolonged processing times boosted the repolymerization of the biocrude to hydrochar. These transformations depended on the reaction medium, with seawater exerting different influences based on the reaction medium salinity. Diluted seawater promoted the dissolution and depolymerization of polysaccharides and proteins in the alga by disrupting the H-bonding networks within these macromolecules, while enriched seawater media favored the deoxygenation and repolymerization of the biocrude. These variations highlighted the bespoke nature of this ‘sea-thermal’ process to furnish liquid and solid biofuels and/or biochemicals. Process optimization based on the formulae developed from the ANOVA of the experimental data showed that 55–60 wt% of the alga could be converted either to energy-dense (30 MJ/kg) biofuels (36 wt% biocrude, with hydrocarbons and fatty acids/esters in high amount, and 20 wt% hydrochar) at 200 °C for 180 min using enriched seawater (64 wt% seawater) as a solvent or to value-added liquids (a nitrogen-rich (88 %) biocrude, including abundant fatty amides and N-heterocycles) at 237 °C for 169 min in seawater. These results lay the first stone toward developing more sustainable marine biorefineries using marine-based solvents to valorize marine feedstocks.This work is financially supported by the National Natural Science Foundation of China (No. 21536007), the 111 project (B17030), and the I + D + i project PID2020-115053RB-I00, funded by Spanish MCIN/AEI/10.13039/501100011033. Yingdong Zhou acknowledges the support from China Scholarship Council (CSC No. 202006240156). Javier Remón and Jesús Gracia are grateful to the Spanish Ministry of Science, Innovation and Universities for their JdC (IJC2018-037110-I) and FPI (PRE2018-085182) fellowships.Peer reviewe
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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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