1,720,963 research outputs found
Catalytic wall flow filters for the reduction of biomass boilers emissions
No full textBiomass is worldwide available and the interest in it as energy source has been increased in the recent years, with the aim to reduce the fossil fuels dependence and to increase energy supply in developing countries. Nevertheless, biomass combustion emissions put some concerns for its environmental acceptance, particularly for carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM) contents, which must be reduced to meet the current environmental limits. Among the different technologies for the abatement of these pollutants, wall flow filters may represent an efficient solution since they allow to combine physical filtration processes for particles removal and catalytic oxidative reactions for solid and gaseous pollutants treatment. In this work, two different types of wall flow filters, respectively made of silicon carbide (SiC) and alumina (Al2O3), have been tested directly at the exhaust of a 30 kW nominal power conventional pellet boiler. The two samples were chemically and structurally characterized before testing. From the first set of experiments, the SiC filters, specifically loaded with 15 %wt and 25 %wt copper ferrite (CuFe2O4) as catalyst, proved to be more suitable for the aim of this research, since they allow to simultaneously reduce CO and PM emissions of about 95 % and 92 % respectively. Different filters geometries, fitting locations inside equipment and new active species deserve further investigations. Copyright © 2014,AIDIC Servizi S.r.l
Osservatorio degli edifici a energia quasi zero (nZEB) in Italia – 2016-2018
Full text linkA partire dal 2021 tutti gli edifici nuovi o soggetti a una ristrutturazione profonda dovranno essere a energia quasi zero (nZEB), ovvero avere un fabbisogno energetico quasi nullo, coperto in misura significativa attraverso fonti rinnovabili. Tale requisito è già obbligatorio per gli edifici pubblici e in alcune regioni che hanno anticipato la data indicata dall’Unione Europea. L’Osservatorio nazionale degli edifici a energia quasi zero (nZEB), avviato nell’ambito della Ricerca di Sistema Elettrico MISE-ENEA, ha rilevato un aumento progressivo degli nZEB anche prima dell’obbligo, ma anche la necessità di azioni formative e informative rivolte ai decisori in vista dell’ambizioso obiettivo di un patrimonio edilizio decarbonizzato al 2050, e ai progettisti e operatori del settore, per l’applicazione di tecnologie diversificate e idonee. La pubblicazione analizza la situazione degli nZEB nel contesto europeo, restituisce una panoramica delle misure di promozione e delle tecnologie adottate per tali edifici stimandone la diffusione e illustra sinteticamente una selezione di casi nZEB realizzati in Italia
Fattori di emissione dalla combustione di legna e pellet in piccoli apparecchi domestici
Full text linkThe aim of this study was to report emission factors of pollutants (i.e., carbon monoxide, nitrogen oxides, non-methane hydrocarbons, particulate matter, polycyclic aromatic hydrocarbons, dioxins) from biomass burning residential heating appliances. The influence of several factors such as biomass type, appliance and combustion cycle was investigated. Four manually fed (6-11 kW) firewood burning and two automatic wood pellets (8.8-25 kW) appliances were tested under real-world operating conditions in order to determine the actual environmental performance of the appliance. The experimental EFs were also compared with the values proposed by the European emission inventory guidebook used in the local inventory in order to evaluate their representativeness of real world emissions.
The composite macropollutant EFs for manually fed appliances are: for CO 5858 g GJ-1, for NOx 122 g GJ-1, NMHC 542 g GJ-1, PM 254 g GJ-1, whereas emissions are much lower for automatic pellets appliances: CO 219 g GJ-1, for NOx 66 g GJ-1, NMHC 5 g GJ-1, PM 85 g GJ-1. The open fireplace appears to have very high emission factors, however traditional and advanced stoves show the highest overall CO EFs. Especially for the advanced stove real-world emissions are far worse than those measured under cycles used for type testing of residential solid fuel appliances. No great difference is observed for different firewood types in batch working appliances, diversely the quality of the pellets is observed to influence directly the emission performance of the automatic appliances. Benzo(b)fluoranthene is the PAH with the highest contribution (110 mg GJ-1 for manual appliances and 2 mg GJ-1 for automatic devices) followed by benzo(a)pyrene (77 mg GJ-1 for manual appliances and 0,8 mg GJ-1 for automatic devices)
Experimental investigations of the influence of transitory phases on small-scale wood combustion emissions
No full textTo investigate the influence of transitory phases on average emission factors of small-scale wood combustion plants, a specific study was carried out. Several on-line measurements have been carried out for the aerosol and gas emitted from an open fireplace (8 kW), a closed fireplace (I I kW), a conventional wood stove (6.5 kW) under different operating conditions during initial kindling and refilling stages. Some tests have also been performed with different fuel types and moisture level. Results confirm that emissions are generally higher during transient phases. The paper provides a description of measuring techniques and results obtained under tested conditions for different pollutants and appliances
Assessing building energy performance and energy policy impact through the combined analysis of EPC data – The Italian case study of SIAPE
Full text linkEnergy Performance Certificates (EPCs) and EPC digital registers are key tools to evaluate different aspects of the building stock and its energy consumption. This paper presents several detailed energy performance evaluations on the Italian buildings based on a sample of over 2,000,000 EPCs extracted from the national EPC register (SIAPE), contributing to the definition of an updated energy performance baseline of the Italian building stock. This is the first work using the Italian EPC register to define such a baseline to the extent of the authors’ knowledge. Furthermore, combined analyses of EPC data were carried out to obtain information on the influence of the Italian energy regulations on building characteristics and on the effectiveness of energy strategy application for building renovation. This study underlines the relevance of EPC registers and how the combined analysis of EPC parameters can provide a large amount of useful information on several aspects of the building stock, allowing the monitoring of the impact of the Italian energy policy framework on buildings energy performance. Finally, based on these results, the paper supports public authorities and decision-makers in planning and developing future energy programs and identifying the best practices on the Italian territory
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
- …
