1,720,982 research outputs found
Studio per il completamento della rete di controllo della qualita’ delle acque superficiali della zona Foci del Tagliamento - Laguna di Marano (Surface Waters Monitoring - The Water Quality Control of Tagliamento River Estuary and the Marano Lagoon)
No full textRapporto CRAD/2-Udin
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
Electrodeposition of nanostructured cobalt films from choline chloride-ethylene glycol Deep Eutectic Solvent
Full text linkAmong the Deep Eutectic Solvents (DESs), ethylene glycol-based one is attracting the attention of many researchers because of its relatively low viscosity with respect to analogous eutectic systems with urea, malonic acid or glycerol. In this work, the electrochemical behavior of Co(II) in a eutectic solution of choline chloride and ethylene glycol (1ChCl:2EG molar ratio) was investigated by cyclic voltammetry (CV) at 70°C followed by galvanostatic deposition (GD). The deposits on copper substrate were characterized with a field emission scanning electron microscope (FE-SEM) showing a nanostructured surface texture with plateletlike architecture resulting in a high hydrophobicity (contact angle CA >135°). By increasing the current density, more compact films were obtained while the addition of boric acid resulted in a finer structure. X-ray diffraction (XRD) analysis determined the coexistence of FCC and HCP phases, both with and without the addition of boric acid to the bath. Annealing in a nitrogen atmosphere was performed at different temperatures (300°C-600°C) to observe microstructure evolution. Magnetic properties with a coercivity of 60-80 Oe were measured by means of micro-indentation and Vibrating Sample Magnetometer (VSM)
Understanding the Failure Mode of Electroless Nickel Immersion Gold Process: In Situ-Raman Spectroscopy and Electrochemical Characterization
Full text linkSince the early 70s, printed circuit boards (PCBs) are firmly entrenched in all electronic branches, from the consumer electronics to scientific and medical equipment, culminating later in the personal computer industry. Electroless nickel immersion gold (ENIG) process is one of the most used selective finishing in PCBs production. It involves two different electroless deposition mechanisms: (1) NiP autocatalytic deposition and (2) gold galvanic immersion plating in which displacement reactions are involved. Because during ENIG process, NiP is dissolved from the electrode surface into the solution, it can be considered as a controlled corrosion process of the metal substrate: selection of the complexing agents in solution is thus crucial. Since they are the most used complexing agents, EDTA and citric acid have been investigated. In order to understand their effects on the NiP surface during the immersion plating, open circuit potential (Voc) and linear sweep voltammetry (LSV) measurements have been performed. Furthermore, to establish which complexes are adsorbed on the electrode surface during the plating process, in situ Raman spectroscopy was carried out showing EDTA to be the most effective Ni cations chelating agent. To assess the effect of Cu contamination, accountable of reddish gold failure mode, the electrochemical and in situ spectroscopic analyses on both immersion gold solution and polluted revealed that the adsorption of Cu(CN)-2 and/or Cu(CN)32- complexes is competitive with Au(CN)-2. To evaluate the effects of copper contamination on gold nucleation and growth FE-SEM and AFM were carried out, while gold layer solderability has been evaluated according to NF-A-89 400 standard
Sn-Cu codeposition from a non-aqueous solution based on ethylene glycol for wafer-bonding applications: direct and pulse electroplating
No full textMetal wafer bonding is being investigated in industry and research fields due to the relatively low process temperatures (T < 500 °C) and, at the same time, to obtain a metallic junction able to offer greater reliability compared with other materials. In this work, electrodeposition of eutectic Sn-Cu alloy, suitable for wafer bonding, was studied using ethylene glycol (EG) as a solvent. The resulting organic electrolyte was used for its promising properties, such as a wider electrochemical window than traditional aqueous electroplating baths. Ethylene glycol solutions containing copper(II) and tin(II) chloride salts were characterised electrochemically by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Deposition was performed both under direct (DC) and pulsed (PC) current conditions and the advantages of the latter are discussed, also in terms of surface morphology as observed by scanning electron microscope (SEM). Wafer bonding was successfully achieved and the interdiffusion of copper and tin species in the bonding region is discussed
Luminescent Solar Concentrators for Photoelectrochemical Water Splitting
No full textSolar-driven electrolysis accomplished through photovoltaic (PV) devices is a major candidate for a long-term sustainable energy economy. However, the visually appealing integration of PV cells or panels into the built environment or in mobile applications is a fundamental requirement for this technology to expand and grow further. In this view, we investigated the exploitation of a luminescent solar concentrator (LSC) comprising multiple c-Si cells connected in series and parallel as a semitransparent device, capable of carrying out water electrolysis without an external bias. The optimized monolithic device comprises two series of four PV cells connected in parallel integrated into a planar LSC of 19.36 cm2 area, externally wired to an electrochemical cell having Pt and Ru-based electrodes as cathode and anode, respectively. LSC devices are evaluated under different illumination conditions, including diffuse light, to simulate urban or indoor environments. Maximum solar-to-hydrogen efficiency (STH) of 1.55% at 1 sun AM 1.5 G can be obtained with this setup, considering the whole front LSC area. These results represent the first demonstration of an electrolysis-based energy storage system exploiting LSC technology
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
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