1,720,956 research outputs found
Technology review and thermodynamic performance study of a biogas-fed micro humid air turbine
No full textBiogas is a proven and valuable energy source today for the combined production of heat and electricity (CHP). One of the most reliable and efficient technologies for the CHP application using biogas is represented by microturbine (MT). This prime mover not only shows a very flexible behavior towards change in the fuel composition, but it also sticks out for its reliability, small size, and low weight. Moreover, micro humid air turbine (mHAT) cycle, which is still under development, provides a relatively simple and inexpensive solution to increasing the power output of the microturbines. In this paper, the thermodynamic model of a novel CHP system based on a 500 kW micro humid air turbine (mHAT) in a wastewater treatment plant (WWTP) is presented and discussed. Furthermore, some considerations regarding an appropriate biogas treatment system and heat recovery module are discussed.
The results presented in this paper show how the proposed biogas-fed plant can achieve an electrical efficiency of 46.6% together with a CHP efficiency of 81.2%. The impact of integration with WWTPs is beneficial where both biogas and required water for inlet air humidification are available
Solutions for improving the energy efficiency in wastewater treatment plants based on solid oxide fuel cell technology
Full text linkPolygeneration configurations for small power generation systems offer significant potential for energy saving and reducing carbon emissions in wastewater treatment facilities. In this work, a biogas-fed solid oxide fuel cell system operating in a wastewater treatment plant (located in Turin, Italy) is analyzed in terms of its potential improvements through novel polygeneration systems. In its present combined heat and power configuration, along with electrical power, thermal energy from the exhaust gas is recovered to provide required heat to the plant’s anaerobic digester. The analysis is focusing on different energy efficiency solutions for this type of plant by using solar thermal collectors, microturbines, a trilateral Rankine cycle, and an absorption chiller. Results reveal that, despite of higher efficiency for the trigeneration case using both trilateral Rankine cycle and absorption chiller (up to 88.4%), the solar integrated system results in the lowest natural gas consumption, which is 38.5% lower than the baseline scenario. This same scenario is also the worst in economic terms due to the high capital costs of solar collectors. In a short-term cost trajectory of the solid oxide fuel cell technology, the most economically favorable scenario is the microturbine integrated case in which the calculated levelized cost of electricity is 0.11 €/kWh, lower than grid electricity price, and with payback time of 6.5 years. Long-term cost trajectory is indeed generating effective investments for all of the four scenarios with payback time between 3 and 5 years in all cases. The analysis has been developed to the entire European Union area: the most suitable market conditions are found in Germany, Denmark, Slovakia, and Italy
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
Techno-economic assessment of biogas-fed CHP hybrid systems in a real wastewater treatment plant
Full text linkThe integration of solid oxide fuel cell (SOFC) systems and micro gas turbines in a reference wastewater
treatment plant is proposed. The main scope is to utilize the available biogas in a real wastewater treat-
ment plant (WWTP) to feed both the SOFCs and micro gas turbines (MGTs) to produce electrical power
while covering the digester thermal demand of the plant. To do so, two cases namely SOFC-WWTP (in
which the SOFC system is the only CHP unit), and SOFC-MGT-WWTP (integration of both SOFCs and
microturbine systems) are proposed. Results show that use of microturbines along with the SOFC systems
can increase the share of electricity covered by self-generation within the WWTP by up to 15% while
keeping stable the coverage of the thermal load. Also, the energy efficiency of the novel system (SOFC-
MGT-WWTP) is calculated to be 7% more than that of the SOFC-WWTP. Economic analysis results reveal
that using microturbines, the payback time for whole the system could be reduced about 4 years. Also, for
the short term scenario, the levelized cost of electricity for the SOFC-MGT-WWTP system is found to be
0.118 $/kWh which is about 12% less than that for the SOFC-WWTP system. However, for the long term
scenario, the difference becomes remarkably les
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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