1,720,955 research outputs found
Dynamic feed scheduling for optimised anaerobic digestion: an optimisation approach for better decision-making to enhance revenue and environmental benefits
No full textAnaerobic digestion (AD) offers a sustainable solution for clean energy production, with the potential for significant revenue enhancement through enhanced decision-making. However, the complexity and limited flexibility of AD systems pose challenges in developing reliable optimisation methods. Changing feeding strategies provides opportunities for efficient feedstock utilisation and optimal gas production, especially in volatile gas markets.To provide better decision-making tools in AD for energy production, we propose an integrated site model for the dynamic behaviour of the AD process in a biomethane-to-grid system and optimise production based on predicted gas prices. The model includes methods for optimal feed co-digestion strategies and integrates these results into a scheduling model to identify the optimal feedstock acquisition, feeding pattern, and potential gas storage operation considering feedstock availability, properties, sustainability, and fluctuating gas demand under different pricing variations.The methodology was tested on a 150 tonnes per day farm-scale AD plant in the UK, processing energy crops and manure considering both environmental (global warming potential) and economic objectives. The results showed strong adaptability of the proposed feeding schedule to the general trend of gas prices over time. To address the challenge of immediate price peaks, typically unattainable due to the system's sluggish behaviour and high retention times, the impacts of on-site storage were explored, leading to annual revenue increases ranging from 2 % to 7.4 %, depending on the pricing scheme, which translates to a significant boost in terms of revenue
Novel life cycle GHG formulations of anaerobic digestion systems aligned with policy
No full textAmidst rising interest in biogas as a sustainable alternative to traditional energy vectors like natural gas, this study focuses on its role in achieving net-zero targets. Biogas, derived from carbon-neutral organic waste, offers significant greenhouse gas (GHG) emission reductions. Life cycle assessments (LCA) are crucial for evaluating the global warming potential (GWP) of biogas, ensuring its effectiveness in offsetting fossil fuel equivalents. Our study introduces two complementary sets of equations, grounded in published literature and LCA databases. Despite their differing structures due to distinctive specific activities across life cycles, both sets yield closely aligned estimations, reinforcing confidence in these models
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
Biogas beyond boundaries: novel algebraic equations for global warming standardization in anaerobic digestion systems with critical life cycle analyses
No full textAmidst rising interest in biogas as a sustainable alternative to traditional energy vectors like natural gas, this study focuses on its role in achieving net-zero targets—where carbon emissions are balanced with sequestration. Biogas, derived from carbon-neutral organic waste, offers significant greenhouse gas (GHG) emission reductions. Life cycle assessments (LCA) are crucial for evaluating the global warming potential (GWP) of biogas, ensuring its effectiveness in offsetting fossil fuel equivalents. However, current GWP calculations lack transparency and standardization, necessitating new robust easily calculable algebraic equations. Our study introduces two complementary sets of equations, grounded in published literature and LCA databases. Despite their differing structures due to distinctive specific activities across life cycles, both sets yield closely aligned estimations, reinforcing confidence in these models. The GWP is sensitive to the feedstock type, electricity and heat consumption, and fugitive emissions. The statistical distributions show the mean GWP of 0.54 per m3 biogas, 0.09 per kWh biomethane and 0.73 per kWh electricity production rates of cradle-to-grave systems with all plausible technologies available in the database. The lowest GWP meets the UK’s 50 g CO2e per kWh biomethane target by 2030 for gas grid injection. The GWP in g CO2e per kg AD feedstock is 93-104 (manure), 16-26 (sludge), and 273 (grass silage), etc. The biowaste AD system reduces at 0.5-0.7 kg CO2e per kWh of electricity generated, requiring 1.5 MWh of minimum threshold electricity generation to reduce 1 tonne of CO2e
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
- …
