1,720,967 research outputs found
Biorefining of high ligno-cellulosic waste biomass via pyrolysis coupled with anaerobic digestion. An LCA study
No full textThe sustainable processing of biomass into a spectrum of products and energy is the goal of a biorefinery. Sustainability is key in this process and all biorefineries should be designed for sustainability along the entire value chain.
A laboratory-scale plant has been built by the University of Bologna, coupling pyrolysis and anaerobic digestion, in order to treat high ligno-cellulosic waste biomass.
This technology set can bring a wider range of exploitable residual biomasses in anaerobic digestion.
A life cycle assessment has been conducted on the use of corn stover in this experimental plant. The assessment included changes in land-use and soil carbon stock, biochar application to agricultural soils, biomass collection and pre-treatment, and biochar valorization as fertilizer and for carbon storage.
The system is compared to a fossil reference system providing the same set of products.
Results show that the process can yield a net energy gain and reduce GHG emissions, but high variability affects some key parameters, such as the energy required by the pyrolyzer and the biogas output from the anaerobic digester. As for the carbon balance, a relevant contribution is given by carbon storage in biochar
Local and regional resource and landscape management from the point of view of the next larger scale: the emergy synthesis perspective
No full textLife Cycle Assessment of high ligno-cellulosic biomass pyrolysis coupled with anaerobic digestion
Full text linkA Life Cycle Assessment is conducted on pyrolysis coupled to anaerobic digestion to treat corn stovers and to obtain bioenergy and biochar. The analysis takes into account the feedstock treatment process, the fate of products and the indirect effects due to crop residue removal. The biochar is considered to be used as solid fuel for coal power plants or as soil conditioner. All results are compared with a corresponding fossil-fuel-based scenario. It is shown that the proposed system always enables relevant primary energy savings of non-renewable sources and a strong reduction of greenhouse gases emissions without worsening the abiotic resources depletion. Conversely, the study points out that the use of corn stovers for mulch is critical when considering acidification and eutrophication impacts. Therefore, removal of corn stovers from the fields must be planned carefully
Modelling of an alternative process technology for biofuel production and assessment of its environmental impacts
No full textIt is easy to predict that in the coming years in Europe biodiesel will play an increasingly important role in the transport sector. The European Commission has set at 10% by 2020 the proportion that biofuels should represent in total fuel used in transport and biodiesel is currently the most widely used biofuel in the European Union. The most common way to produce biodiesel is through transesterification of vegetable oils with methanol; glycerol is the main co-product. Although glycerol has many industrial applications, increased production of biodiesel could make complete market placement of this chemical difficult. In this context, increasing interest is paid towards different methods of biodiesel production that provide alternative co-products. This article offers a "cradle to gate" evaluation of potential environmental impacts caused by an innovative process for the production of DMC-BioD, an alternative biofuel to biodiesel which does not involve the production of glycerol. Transesterification of soybean oil with dimethyl carbonate to obtain DMC-BioD has been modelled with the aid of the Chemical Process Simulation software Aspen HYSYS® that produced the material and energy balances and the preliminary sizing of the process units. Results have been also compared with background information from database on the production of conventional biodiesel from soybean oil and of fossil diesel. The study suggests that DMC-BioD can be an interesting route for the production of biofuels from an environmental point of view. Compared to fossil diesel, GHG (Greenhouse gases) emissions can be decreased, although trade-offs are registered in other environmental categories. In any case, future investigation is needed in order to understand and optimize its environmental profile through the entire life cycle and possibly bring its production to a commercial scale. This preliminary analysis of potential environmental impacts provides useful information to continue the testing and scale-up phases and to improve the environmental performances of the process
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
Indicators, emergetic thresholds and constraints for coastal spatial planning and management
No full textThe article describes the method chosen for the definition of a development scenario and a set of indicators for integrated coastal zones management. The case studies are in the Center and North Adriatic Sea (Italy, Mediterranean Sea). Selected areas are the Lagoon of Venice, the Province of Rimini and the Conero coastal area. The development of indices and indicators set focuses on sub-regional and local sustainability of coastal management. A multi-scale and diachronic approach based on landscape and seascape ecology is build in order to develop the dynamics of indices set. The indices results are the threshold for carbon, ecological and space footprints.
The used approach provides the following results: identification of conflicts and urban sprawl, assessment of degree of sustainability (carbon footprint, ecological footprint, emergy and LDI), assessment of change during the last 30 years. Indicators are developed dealing with both landscape ecology and health of ecosystems. Modeling these changes is critical for formulating effective environmental policies and management strategies The developed model provides suitability maps per each area in order to maximize different policy objectives reducing the coastal conflicts. A final scenario is proposed and assessed in each case studied
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
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