1,720,960 research outputs found
Geothermal energy for drying of wastewater sludge and electricity production
No full textWaste treatment and disposal and electric energy production are crucial challenges in geographically disadvantaged
areas, such as small islands, due to limited connection with mainland. Scarce land availability, environmental
restrictions and tourism activity, that often characterize small islands, make difficult to adopt ordinary
technical solutions, increasing these issues. Then, the most common strategy for waste disposal is shipping to
the mainland, whereas electricity generation is based on the importation of fossil fuels for local production.
Both these options make small islands strongly dependent on the mainland, and cause significant energetic, environmental
and economic costs. For these reasons, the use of renewable energy sources for waste treatment
and energy production is particularly attracting in small islands.
In this work, geothermal energy at medium enthalpy is considered to produce heat for thermal drying of
wastewater sludge and to power an Organic Rankine Cycle system for electric energy production. The analysis
is carried out for the case study of a small Italian island.
The geo-fluid, through an air-water heat exchanger, heats fresh air to produce the desiccant current for sludge
drying, which is carried out by using a belt convective dryer, operating in the range of 90.0-180°C. The dryer is
designed to achieve a final solids content of dry sludge higher than 90.0%. A fraction of the desiccant current
exiting the dryer is recirculated in order to reduce thermal energy demand of the dryer and, at the same time, the
flow rate of exhausts to be treated. Before reinjection, the geo-fluid powers a small-scale ORC system, designed
to self-supply the proposed layout, providing electricity for the dryer and the geo-fluid pumps, and to produce
electricity for the wastewater treatment facilities.
An energy analysis of the proposed system is carried out through the software Aspen PLUS, and an economic
and environmental model is developed to assess its profitability. This model estimates the economic and environmental
benefits coming from sludge drying, which significantly decreases the amount of sludge to be transported
and disposed, and from the use of a renewable energy source with respect to conventional fossil fuels,
for sludge treatment and electric energy production
Energy Management in Geothermal Energy Systems
No full textAuthors propose a thermoeconomic analysis of a renewable polygeneration system producing power, desalinated water, heating and cooling and connected to a district heating and cooling network supplying a small district. A comparison between two layouts is performed, a hybrid (solar and geothermal) and a geothermal one, by performing a 1-year dynamic simulation and processing the results on different time bases. A parametric analysis is carried out to assess system performance and its capability to match the time-dependent energy demands. The hybrid configuration provides the best thermodynamic and environmental performances; conversely the geothermal one provides the highest economical profitability, achieving a much lower simple payback time, averaging 4.3 years instead of the 8.4 years of the hybrid configuration
Exergetic and exergoeconomic analysis of a novel hybrid solar-geothermal polygeneration system producing energy and water
No full text
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
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
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