1,721,143 research outputs found
Advanced carbon-based nanostructured materials for energy storage devices
Full text linkCommercially available batteries and capacitors normally use carbonaceous electrodes. However, since common graphite is often limited by its poor performances, alternative structures and morphologies could be developed. The possibility of exploiting innovative synthesis processes and virtuous alternative sources for advanced carbon-based materials opens new perspectives in a global scenario where the push for energy transition becomes progressively critical.
Aiming at studying innovative pure or composites carbon materials for electrochemical devices, i.e. lithium-ion batteries and supercapacitors, this thesis includes the development of synthetic processes (i.e. following purely chemical routes or exploiting agricultural wastes), electrochemical testing, optimization of the device features, and a feasibility study of advanced characterization in operando.
Hybrid C/Si anodes for lithium-ion batteries have been studied for many years. Carbon softness, conductivity, and capability of intercalating lithium ions are ideal to prevent the volumetric expansion of silicon lattice during cyclations. To obtain a composite anode material, carbon nanowalls (CNW) have been synthesized via CVD and combined with Si nanoparticles: the CNW outer layer proved to be able to protect Si beneath.
In a view of green transition, rice husk has been used as a C source to produce carbon aerogels (CAs) and carbon dots (CDs). First, a synthetic process has been developed to obtain the nanostructures, whose properties as electrode materials have been evaluated both in supercapacitors and lithium-ion batteries. The reported results show the efficacy of RH derivatives as resistant cost effective alternatives to currently available materials in both devices.
Prior to electrochemical testing, detailed characterization of all the abovementioned materials have been performed by means of SEM, EDS, AFM; XRD; Raman Spectroscopy, X ray Tomography and BET analysis. Besides routinary characterization, preliminary tests with AFM on electrodes have been conducted aiming at the optimization of our system to perform in operando electrochemical AFM
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
Te la farò pagare...False accuse di abuso sessuale intrafamiliare come vendetta nei casi di alienazione genitoriale e conflittualità coniugale
No full textIl lavoro presenta un fenomeno di particolare rilevanza che può emergere, nel contesto delle dispute tra genitori separati per l’affidamento dei figli, in qualità di derivato o effetto della Sindrome di Alienazione Genitoriale: le false accuse di abuso sessuale intrafamiliare. Si assiste, infatti, sempre più di frequente a vicende giudiziarie che seguono un iter caratteristico: un genitore viene accusato di abusi o gravi maltrattamenti ai danni del figlio e viene allontanato, sospendendo ogni relazione con il bambino; il lungo percorso investigativo e giudiziario non conferma la denuncia ma, nel frattempo, il rapporto genitore-figlio è compromesso irrimediabilmente. Si desume, dunque, l’importanza di un’accurata differenziazione tra accuse bona fide di abuso e denunce frutto di una PAS: a tale scopo Gardner (1999) fornisce un lungo elenco di criteri che fanno riferimento sia ai pattern comportamentali dei minori che alle caratteristiche psicologiche, agli atteggiamenti e alla storia familiare dei genitori. In caso di abuso realmente subito dal genitore rifiutato, i sintomi dei figli rientrano solitamente nell’area del Disturbo Post-traumatico da Stress (A.P.A., 2001), e difficilmente si riscontrano le manifestazioni tipiche della PAS. Quanto alle figure parentali, solitamente i genitori alienanti sono poco collaborativi nel sottoporsi a valutazioni, poco attendibili nei loro resoconti, bisognosi di fare continue “iniezioni di richiamo” per ricordare ai figli i maltrattamenti subiti, premurosi nel proteggere i figli dal genitore bersaglio, anche in contesti protetti; denunciano, inoltre, i presunti abusi solo dopo la separazione. I genitori di minori realmente abusati, invece, lasciano che i figli ricordino spontaneamente gli abusi subiti, riconoscono il rischio dell’indebolimento del rapporto tra il genitore abusante ed i figli e fanno di tutto per ripristinarlo in condizioni protette; la denuncia degli abusi risale, infine, ad un periodo di molto precedente alla separazione. I genitori bersaglio della PAS, spesso, sono attendibili nei loro resoconti; si sono in genere preoccupati del benessere familiare; le denunce di abuso mosse loro riguardano solo i figli, non gli altri familiari. I genitori realmente abusanti, al contrario, sono poco attendibili nei loro resoconti, poco o affatto interessati al benessere della famiglia, tendono all’impulsività, all’esplosione violenta della rabbia; la denuncia di abuso può estendersi , in questi casi, anche ad altri membri della famigli
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
La valutazione psicodiagnostica del minore abusato, aspetti metodologici in ambito forense
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
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