1,720,969 research outputs found
Application of biochar as additive in Anaerobic Digestion
Full text linkL'abstract è presente nell'allegato / the abstract is in the attachmen
Saving Energy by Delegating Network Activity to Home Gateways
No full textToday, an ever-increasing number of devices has networking capability. The main implication of this fact is that such devices are often left fully powered yet idle just to maintain their network presence, hence leading to large energy waste. This ultimately results in higher electricity cost for consumers. This paper tackles an effective mechanism to reduce energy waste of consumer electronics, by boosting the usage of lowpower states available in most devices. The main concept is to delegate background networking routines to home gateways, which are today available in most homes and offices. The paper describes the functionality and the software architecture to be implemented by home gateways and consumer electronics, reports performance evaluation on a working prototype, and provides estimation of potential benefits for consumers
Fattibilità tecnico-economica e finanziaria di nuove tecnologie nella riqualificazione energetica di edifici residenziali
No full textThe revision of the Energy Performance of Building Directive (EPBD) provides for the construction of zero-emission buildings. The present work investigates possible solu-tions aimed at phasing out fossil fuel heating systems in buildings, in accordance with the EPBD requirements. A case study of a residential building located in Rome is presented. The proposed refurbishment approach is based on the reduction of energy need through thermal insulation and the heating system upgrade (heat pump or hydrogen fuel cell), and the use of renewable energy produced by a photovoltaic system. The results show that, although the energy optimal solution is the thermal insulation associated with the replace-ment of the heat generator with a heat pump coupled to a PV system, from an economic-financial point of view the thermal insulation intervention is not convenient
Impact of biochar on anaerobic digestion: Meta-analysis and economic evaluation
Full text linkThe growing global energy demand encourages the request for renewable sources, as biomethane from the
anaerobic digestion (AD) of waste biomass. Biochar (BC) can effectively increase methane production when
supplemented to AD, depending on BC physico-chemical properties. This study was developed in two phases.
Firstly, a systematic meta-analysis of current literature was performed to correlate AD performance with BC
properties, aiming to define their optimal range. The obtained results prove that BC enhances and accelerates
biomethane production. Considering 408 experimental conditions of 76 studies in batch mode, biomethane yield
and maximum production rate were significantly increased by BC addition. From the results of the subgroups
meta-analysis, an optimal range of BC physico-chemical properties may be suggested as follows: high ash (≥
20%) and low C contents (< 50%), high O/C molar ratios (≥ 0.3), high contents of O (≥ 20%) and N (≥ 0.6%),
acidic pH (< 7.0), low surface area (< 10 m2 g-1). Secondly, an economic analysis aimed at assessing the
economic profitability of BC addition to an existing AD plant suggest avoiding a dose above 0.45–0.76 gBC gVS -1, independently of the specific AD operating conditions. In conclusion, BC application in full-scale digesters is able to maximize biomethane production and economically feasible
Technical-economic and financial feasibility of new technologies in the energy refurbishment of residential buildings
Full text linkThe revision of the Energy Performance of Building Directive (EPBD) provides for the construction of zero-emission buildings. The present work investigates possible solutions aimed at phasing out fossil fuel systems in buildings, in accordance with the EPBD requirements. An insulated residential building located in Rome is presented. The proposed refurbishment approach is based on the heating system replacement (heat pump, hydrogen fuel cell, hydrogen-ready boiler), and the use of renewable energy produced by a photovoltaic system. The results show that, although the energy optimal solution consists of the replacement of the heat plant with a heat pump coupled to both a PV and a fuel cell system, from the economicfinancial point of view the proven solution of heat pump coupled with PV is still the only feasible one
Investigation of pre-treatments improving low-temperature anaerobic digestion of waste activated sludge
Full text linktThis work analyzed the feasibility of pre-treatments to improve the anaerobic digestion (AD) of wasteactivated sludge (WAS) at 20◦C. We investigated different physicochemical pre-treatments (thermal at115◦C, thermo-alkaline at pH 10 and 70◦C and ozonation at 190 mg-O3L−1) by comparing their perfor-mances about COD solubilization and sludge disintegration rate. Best performances were obtained bythermo-alkaline pre-treatment, followed by thermal and ozonation; results were consistent with litera-ture. Pre-treated WAS was fed to 12 1-L anaerobic digesters operated in semi-continuous mode. Thermaland thermo-alkaline reactors produced biogas yields (0.30–0.36 m3kg−1VS in standard conditions, 65–70% methane) analogous to mesophilic conditions. The economic assessment of the scale-up of the wholeprocess demonstrated that thermo-alkaline pre-treatment made AD at 20◦C economically profitable forWAS generated by a 20,000 PE WWTP
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
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