1,720,967 research outputs found
System dynamics as a tool to include time-dependent factors in environmental assessment modelling
No full textLife Cycle Assessment (LCA), as conceived in ISO 14040 series, is based on a steady state and linear model. Time dimension is not considered and changes in time are not foreseen. Therefore, the oversimplified ISO LCA structure could fail to capture complex dynamics evolving over time, which in some cases can be crucial in providing a proper environmental assessment. Several attempts to introduce time dimension in LCA modelling, with particular regard to Life Cycle Inventory (LCI), have been proposed in the past, but dynamic approaches to LCA are still pioneering. On the other hand, system dynamics represents a well-established method for analysing the interrelationships and feedbacks existing within complex systems, thus exploring the non-linear and time dependent causalities and consequences reflective of real world behaviour. Our research group is studying the way for combining system dynamics and LCA to implement a dynamic LCI. The methodology proposed would find application within the European projects Star-Pro-Bio, aimed at the development of sustainability assessment tools for bio-based products, and TO-SYN-FUEL, aimed to demonstrate the conversion of biomass into advanced biofuels. The present work represents an exercise where a system dynamics modelling framework is built in order to implement a dynamic LCI. The main objective is to provide an example case of generation of inventory data for life cycle environmental assessment, considering their interrelationship with a multiplicity of
time-dependent and case-specific environmental and economic variables in a unique comprehensive framework. In this way, complex dynamics can be managed and made explicit, allowing the study to highlight how they affect the assessment of environmental impacts. Starting from a marginal demand for biomass feedstock (e.g. maize) generated by the production of a novel bio-based product, the aim of the developed system dynamics model is to quantify the increased use of fertilizers and the consequent change in their stock in agricultural land, which is also mutually linked to the quantity of chemical compounds emitted into the environmental compartments. This way, varying the production of the novel bio-based product will provide a dynamic inventory of the fertilizer-derived emissions. Emissions generated over time can ultimately be converted into environmental impacts through conventional characterisation factors
Hydrogeological characterization of small coastal wetlands and forests in the Southern Po Plain (Northern Italy).
No full textThis study is aimed to characterize the shallow groundwater system in the coastal area between the Uniti and Bevano rivers (southern part of the Po plain), where salinization is threatening the coastal ecosystems and posing a major environmental issue for the phreatic water management in the coast. A thin rainwater lens is present at the top of the aquifer in the backshore area and its extent has a seasonal variability. These few centimetres of freshwater represent a thin interface between sea water and the delicate coastal ecosystems, such as those of dunes and wetlands. To have a better understanding of the changes in groundwater chemistry, we performed a seasonal monitoring of the water quality at the top of the aquifer. Effective concentrations of chemicals and actual values of physical-chemical parameters in the rainwater lens could be measured by means of auger holes. The analysis of the cation-exchange process in the aquifer was made through the application of the Base Exchange index (BEX index) of Stuyfzand (2008), an indicator of salinization or freshening of waters. The results pointed out that a salinization process is taking place in the largest part of the aquifer. Extension and chemical composition of the rainwater lens are strongly influenced by anthropogenic factors such as drainage and land use. The surface water bodies are all brackish to salty and characterized by anoxic and reducing conditions. At present, only halophytes are present around the dune slacks, which have turned into brackish to hypersaline lakes
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
Lenti d'acqua dolce nelle dune della costa Adriatico-Romagnola
No full textStudi condotti negli ultimi sette anni sulle dune costiere relitte della costa Adriatico-Romagnola hanno rilevato l’esistenza di lenti di acqua dolce al loro interno. Queste lenti di acqua dolce sono importanti per l’ecosistema delle zone umide costiere e per contrastare l’intrusione di acqua salina nell’acquifero freatico. Studi geochimici delle acque di falda contenute nelle dune indicano che è in atto una tendenza alla progressiva salinizzazione di questa risorsa idrica che peraltro è soggetta a forti oscillazioni in quantità e qualità durante le diverse stagioni dell’anno. Le ragioni di questa progressiva salinizzazione delle acque contenute nelle dune sono da ricercarsi nel drenaggio della zona costiera, nella presenza di vegetazione non in equilibrio con il locale ecosistema, nella subsidenza, nell’innalzamento del livello marino e nel progressivo smantellamento degli apparati di dune rimasti a causa di fattori antropici e naturali. Studi di modellistica analitica e numerica indicano che le dune costiere romagnole sarebbero ancora in grado di mantenere una lente di acqua dolce spessa alcuni metri se esse non fossero costantemente drenate. Dove la duna costiera è stata ricostituita, come è il caso di Foce Bevano, almeno per un anno dopo l’intervento si è registrata una tendenza alla formazione di una nuova lente di acqua dolce all’interno della duna artificiale. Le dune costiere per le loro caratteristiche di ottimi serbatoi, date la loro alta conduttività idraulica e porosità, sono dei luoghi ideali per interventi di ravvenamento artificiale dell’acqua sotterranea. Un ravvenamento artificiale in una duna oltre ad immagazzinare acqua che può poi essere utilizzata in periodi di siccità dall’ecosistema circostante permette anche la formazione di un battente d’acqua sopra il livello del mare che come previsto dalla legge di Ghyben-Herzberg costituisce una forte barriera contro l’intrusione di acqua salina negli acquiferi dell’entroterra
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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