1,720,970 research outputs found
Cold-ironing portuale: stato dell'arte e possibili sviluppi
No full textNegli ultimi anni i temi riguardanti l'ambiente hanno assunto un ruolo sempre crescente nello sviluppo e nell'economia di un paese, coinvolgendo varie tipologie di soggetti, dalla più grande multinazionale al singolo cittadino. Così, anche nei traffici
commerciali, i vari sistemi di trasporto si sono evoluti cercando di rispettare le varie norme poste a salvaguardia dell'ambiente stesso. Questo fenomeno è stato sicuramente evidente per i veicoli terrestri, che hanno subito un' importante riduzione delle
emissioni atmosferiche negli ultimi 20-25 anni, mentre non si può dire altrettanto per i trasporti marittimi. Con l'aumentare dei traffici via mare negli ultimi anni però, l'aumento delle emissioni si è rivelato un problema di sempre maggior peso, spingendo
così le varie organizzazioni internazionali verso l'adozione di tecniche di salvaguardia dell'ambiente. Ovviamente, parlando di traffici marittimi, la constatazione più evidente del problema si nota soprattutto nelle aree portuali piuttosto che nelle tratte in mare aperto dove gli effetti delle emissioni sono meno visibili anche se altrettanto importanti. L'aumento dei fattori di rischio di malattie sugli abitanti delle zone adiacenti i bacini portuali ha determinato l'urgenza di adottare tecniche operative a salvaguardia della salute dei cittadini.
Uno strumento per ridurre le emissioni delle navi in porto è quello di provvedere all'alimentazione dei generatori di bordo tramite collegamento alla rete elettrica nazionale piuttosto che con gli stessi motori ausiliari delle navi. Infatti durante le fasi di sosta o durante le operazioni di carico/scarico gli impianti di bordo, quali i mezzi di movimentazione, gli impianti di illuminazione, riscaldamento, e gli impianti che provvedono al funzionamento di tutte le applicazioni elettriche, dalle più semplici alle più complesse (esempio navi da crociera), devono essere perfettamente funzionanti anche quando la nave è ferma in banchina. A questo provvedono i motori ausiliari, che quindi non vengono mai spenti ed oltretutto sono alimentati a loro volta da carburanti economici, di scarsa qualità che possono arrivare a contenere anche tassi
di zolfo maggiori di 2000 volte rispetto alle autovetture diesel. Questo processo, che permette il collegamento alla rete elettrica nazionale e lo spegnimento dei motori ausiliari, è detto cold-ironing. L'effettiva applicabilità del processo richiede però un'attenta analisi della differenti situazioni operative.
Nel presente articolo verrà analizzata l’attuale stato dell’arte sull’utilizzo del suddetto in ambito nazionale, comunitari e mondiale, ponendo attenzione alle differenti e principali problematiche riguardanti la sua realizzazione
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
Walk_ing progress, proposta progettuale candidata al concorso di idee “Ritrovarsi nel Largo”
No full textIl materiale scheletrico della cripta della chiesa di San Sepolcro in Cagliari. (Nota preliminare)
No full textDispelling 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
Technical-economical analysis of cold-ironing. Case study of Venice cruise terminal
Full text linkCold-ironing is the practice that enables to power commercial ships by a link to fixed electricity network, in order to reduce pollutant emissions in the port areas caused by marine fuels in auxiliaries engines feeding on board installations during ships stops at quays. The present paper aims to provide an overview of the most important technical and functional features of the concerned ships power systems and to analyze the technical, economic and financial feasibility of this system. In the first part the main technical-constructive elements for the application of Cold-ironing to different types of ship (such as voltage, frequency, power supply and power demand on the quay) are analyzed. The variety of functional situations does not allow to establish general constructive solutions since the cold-ironing system is depending both on the operational mode and the layout of each terminal. In the second part of the paper it has been analyzed the case study of the cruise terminal in Venice (VTP Spa Venice Passenger Terminal) with the aim of verifying the feasibility of a cold-ironing system for power supply of cruise ships on quays. The analysis was based on ships timetable for the year 2012, which includes the arrivals and the departures of 86 different ships with a global volume of 570 movements. Starting from data on dwell times, following the guidelines of the MEET methodology for estimating emission factors [3] it has been estimated pollutant emissions (nitrogen oxide NOx, sulfur oxides SOx, volatile organic compounds VOC, particulates PM, carbon monoxide CO) as a basis to calculate externalities to be considered for the Cost-Benefit Analysis (CBA). Based on a probabilistic analysis of the terminal occupation by ships (disposal of ship stalls on each quays) five operational scenarios were defined. Each scenario has been defined on the basis of an economic evaluation by means of a cost-benefit parametric analysis with the aim of providing the maximum financial results for assigned budgets. From a comparison of the results of the cost-benefit analysis and an estimate of possible investment costs obtained from USA case studies, it is noticed that the scenario providing coverage of both financial and economic investment includes the minimum number of electrified stalls and a ships journeys reorganization. It was also proposed a sensitivity analysis of CBA for the evaluation of indicators variations according to reference conditions variation
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