1,720,970 research outputs found
Artificial intelligence driven process optimization for cleaner production of biomass with co-valorization of wastewater and flue gas in an algal biorefinery
No full textIn the present study, an optimized process involving integrated events of flue gas CO2 sequestration and wastewater utilization was developed for improved microalgal biomass production in a cleaner fashion. An artificial neural network (ANN) combined with genetic algorithm (GA) optimization tool was employed for predicting optimal process conditions for enhancing the biomass of the green microalga, Scenedesmus sp., using domestic wastewater as culture medium and coal-fired flue gas as carbon source in an integrated process chain. A 2(4) central composite design involving four independent process parameters such as light intensity, photoperiod, temperature and initial pH as input variables with biomass productivity as the output was used to construct a non-linear ANN model followed by GA tool to predict optimal combinations of process conditions. Among the tested neural network architecture, 4-12-1 ANN topology was found to be the optimal network architecture in terms of maximum correlation coefficient (R = 0.9947) and minimum mean square error as the performance indexes. On employing the optimized ANN model as fitness function in GA tool, the optimum values of the process parameters for efficient biomass production were as follows: light intensity = 124 mu mol m(-2) s(-1), photoperiod; L:D = 17:7 (h), temperature = 27.5 degrees C and initial pH = 9.5. These parameters improved the algal biomass productivity by about 57%, CO2 sequestration rate of 578.1 +/- 23.1 mg L-1 d(-1) and chemical oxygen demand (COD) reduction of 95.9 +/- 2.4% were achieved. The optimized process yielded biomass with lipid content and productivity of 34.6% and 106.4 mg L-1 d(-1) respectively. The biofuel assessment from the fatty acid methyl ester profile obtained also conformed to the international standard specifications for biodiesel. (C) 2018 Elsevier Ltd. All rights reserved.
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
Process integration to co-produce biodiesel, biochar and lutein from wastewater grown microalgal feedstock: A biorefinery concept
No full textThe thesis presents a holistic approach towards establishing a sustainable green integrated biorefinery system with improved biomass, lipid and lutein productivity for potential biodiesel and healthcare applications, while simultaneously remediating wastewater, sequestering CO₂, and producing biochar capable of removing metformin, an antidiabetic drug from contaminated water. The thesis highlights the strategic cultivation process utilizing wastewater cocktail as a substitute for expensive medium, followed by process scale up and conversion of biomass into biofuel and biochar in a biorefinery model with an overall aim to develop a bio-based carbon neutral circular economy. The cultivation process of Chlorella minutissima in wastewater cocktail was optimized following the Taguchi’s L9 (4-factor-3-level) orthogonal array. Results obtained indicate that S3 (5% CO₂, 100mg L⁻¹ of acetate, 10g L⁻¹ of poultry litter, and 15,000 lux of light intensity) combination as the optimum cultivation condition providing enhancement in biomass productivity (292mg L⁻¹ d⁻¹) with high CO₂ fixation rate and photosynthetic efficiency. Additionally, 169.29 mg L⁻¹ d⁻¹) of lipid and 7.21mg L⁻¹ d⁻¹) of lutein productivity within 7 d of cultivation was observed while remediating up to 90-93% of nitrogenous and phosphate substrates. Cellular kinetics of Chlorella minutissima cultivated under the array was explained by Monod model and a logistic equation. Monod kinetics constant: maximum specific growth rate (µmax) was highest for S5 and S3 (1.955±0.01; 1.258±0.03 d⁻¹) and substrate affinity coefficient (Ks) was highest for S1 and S7 (345.4±1.45; 35.25±5.2 mg L⁻¹) factorial combination. The values for kinetic constants obtained for all the combinations show that Chlorella minutissima was able to grow faster under the cultivation conditions of S3, S4, S5 and S7 with a high affinity for the growth limiting substrate, nitrate, as indicated by a low value of KS. The Luedeking-Piret’s model predictions for lipid and lutein were in agreement with the measured data and for lipid it was observed to be growth associated in most cases, whereas for lutein mostly non-growth observations were recorded. Wastewater remediation capacity and CO₂ utilization potential of Chlorella minutissima from flue gas in a raceway pond was evaluated separately. Following the optimum cultivation conditions a mix of 20% kitchen waste and 10 g L⁻¹ of poultry litter waste was maintained, while replacing 5% CO₂ with flue gas during the outdoor cultivation. A biomass productivity of 6.21 ± 0.16 g m⁻² day⁻¹ with a specific growth rate of 0.34 ± 0.03 day⁻¹ was achieved during winter season. Furthermore, lipid content with appropriate fatty acid composition 1.04:1 (saturation: unsaturation) increased more than two-fold (25% to 58%). Additionally, lutein productivity of 1.2 ±0.08 mgL⁻¹ day⁻¹, while utilizing 80.74 ±0.07mg L⁻¹ day⁻¹ of CO² from 5% flue gas was achieved. Taguchi’s L4 (3-factor-2-level) array was used to optimize biochar production derived from different sources (macroalgae: Sargassum sp., agricultural waste: rice husk and lignocellulosic waste: pine wood). Results indicated that temperature and mixing ratio were the most influential contributing factor. The optimum condition to get an enhanced biochar in terms of thermal stability, aromaticity, pH balance, ash content and yield was suggested. Here macroalgae was used first to get an idea of the pyrolysis process and then following this work macroalgae was replaced with raceway pond produced Chlorella biomass. Finally, both macro (MAC) and micro algae (MIC) derived biochar were modified via H₂O₂ activation method and were evaluated for their adsorptive removal capacity for an emerging contaminant, metformin (MET) by performing batch sorption studies. Freundlich sorption isotherm suggested high non-linearity with N values ranging anywhere from 0.3 to 1.54 and predicted bonding sites was mainly attributed to the surface functional groups of the modified biochar. The activated biochar showed favourable adsorption of MET up to 76% of MET removal from the contaminated water at pH 7. The X-ray photoelectron spectroscopy, energy dispersive x-ray and elemental analysis confirmed that incorporation of oxygen containing surface functional groups after modification strengthened the chemisorption as the main mechanism of sorption. Fourier transform infrared spectroscopy and other surface functional group analysis along with lowest Zeta potential at pH 7 reinforced our proposed sorption mechanism. Overall, a waste derived carbon neutral and carbon negative energy along with a high value product was successfully developed in an eco-friendly manner, while gaining on carbon footprints
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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