1,720,967 research outputs found
Determination of extremely localized molecular orbitals in the framework of density functional theory
No full textExtremely localized molecular orbitals are rigorously localized on only a preselected set of atoms and do not have any tails outside the localization region. The importance of these orbitals lies in their ability to be transferred from one molecule to another one. A new algorithm to determine extremely localized molecular orbitals in the framework of the density functional theory method is presented. This could also be a valuable tool in the quantum mechanics/molecular mechanics methodology where localized molecular orbitals are used to describe covalent bonds across the frontier region. The present approach is used to build up the electron density of thymopentin, a polypeptide constituted by five residues, starting from extremely localized molecular orbitals determined on a set of model molecules. The results obtained confirm good transferability properties for these orbitals
Supplemental Material - Changing the Microstructural and Chemical Properties of Graphene Oxide Through a Chemical Route
No full textSupplemental Material for Changing the Microstructural and Chemical Properties of Graphene Oxide Through a Chemical Route by Maria Lucia Protopapa, Emiliano Burresi, Martino Plamisano, Emanuela Pesce, Loredana Latterini, Nicola Taurisano, Giulia Quaglia, Raffaello Mazzaro, and Vittorio Morandi in Applied Spectroscopy</p
Control methodology for biomasses quality: A case study for biotreated poultry manure
No full textThis issue describes a case-study of a static pilot treatment of caged laying hen manure, in egg production, to obtain a marketable high quality organic fertilizer. In the framework of an European running project (FERPODE Project, No 239083, Ecoinnovation), a complex monitoring system has been applied and a scheduled sampling has been performed, in particular to check maturity degree and nutrient speciation and behaviour, according to an European patent pending process. The scope of the research is to define a simplified method to check maturation degree and slow release nitrogen, as quality control on final product designed for agricultural uses
Poly-Siloxane Impregnation and Pyrolysis of Basalt Fibers for the Cost-Effective Production of CFCCs
No full textIn this work, the optimisation of basalt fiber CFCCs (Continuous Fiber Ceramic
Composites) production is presented, focusing on the development of a silicon-oxycarbide matrix
by PIP (Polymer Impregnation Pyrolysis). The use of low cost poly-siloxanes and basalt fibers is
particularly promising for transports and constructions, where thermostructural CFCCs would be
interesting for vehicle weight reduction and fire-resistant panels, but only on the condition that
production costs are kept really low. The basalt/SiCO composites are suitable for mechanical
applications up to 600°C and stand up temperatures up to 1200°C, also in oxidative environments.
The key parameters to keep the production costs low are the furnace and moulds type, being steel
probably the best material for both, since it withstands the pyrolysis temperature and can be easily
cleaned, by oxidation, from any residue. Regarding the pyrolysis environment, two conditions were
compared, nitrogen flow and vacuum, being perhaps the vacuum procedure less expensive and so
potentially more appealing for a large scale production. The microstructure and the
thermomechanical characteristics of the obtained composites were compared. Another key
parameter in determining the production costs is the number of PIP steps, which has to be
minimised. The present results support the conclusion that one PIP step in nitrogen or two PIP steps
in vacuum can provide CFCC with satisfactory mechanical characteristics for thermomechanical
applications in oxidative environments
Microstructural characterization of activated carbon obtained from waste tires
No full textSOREME project (LIFE 11 ENV/IT/109) is aimed at synthesizing an innovative sorbent based on activated carbon obtained from the carbonization of waste tires. Microstructural
characterization was mainly performed in order to define crystallinity, morphology and porosity of the activated carbon powders obtained in different conditions. In particular,
XRD analysis always revealed a partially crystalline structure with different crystallite size of the nanographitic structure.
The disorder of these structures was determined by Raman spectroscopy. This evaluation was made on the basis of the ratio of the integrated area of the D and G bands typical of the graphitic structure. Finally, SEM was used to put in evidence the mesopores and macropores
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
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