1,720,959 research outputs found
Rapid non-contact detection of chemical warfare agents by laser photoacoustic spectroscopy
Get PDFNerve agents have recently been used in battlefield operations, espionage wars, and terrorist attacks. These compounds, like some pesticides, cause organophosphate poisoning. The rapid, noncontact detection of a sarin simulant in the liquid phase has been demonstrated at the Diagnostics and Metrology Laboratory of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development using laser photoacoustic spectroscopy, an infrared absorption technology. The first measurements, carried out with an experimental system based on a quantum cascade laser and developed for the assessment of food authenticity in the "fingerprint region", show that a detection limit of one nanolitre is within the reach of the instrument when chemometric analysis is applied
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Nanomaterials and nanofabrication for next generation photovoltaics
No full textOn December 2015, almost 200 countries were represented in Paris, discussing on the topics of climate change and Kyoto Protocol. According to the organizing committee at the outset of the talks, the expected key result was an agreement to set a goal of limiting global warming to less than 2°C compared to pre-industrial levels [1]. In order to reach this goal, huge cut on polluted emissions has to be done, finding new resources to produce energy. Photovoltaics is a sustainable and environmentally clean energy source that has the potential to become one of the main ones, in the near future. In order for this to happen, photovoltaics needs to be economically competitive with other conventional energy sources: despite the price of conventional Si solar cells dropped from ~4 USD/WP to ~0.54 USD/WP in the last 15 years [2], the use of new materials to get even more low-cost solar cells created the field of the so-called “new generation photovoltaics”.
Organic (polymeric and small molecules) solar cells have been extensively investigated, in the last years, not only for the potential low fabrication costs, but also for the possibility of building integration and for the solution process realization that allows spray, Roll-toroll and printing techniques, over rigid or flexible substrates. Moreover, perovskite solar cells, that are also compatible with the above mentioned production methods, recently outperformed multicrystalline Si, showing an impressive certified efficiency of 22.1 % [3]. This “new gen” solar cells strictly rely on research performed in the nanometric world: the typical thickness of an active layer for organic solar cell is hundreds of nanometers; phase separation between different components of polymeric solutions are investigated by the mean of Atomic Force Microscopy, which allows to see features in the order of some nanometers; perovskite is likely deposited on top of scaffold with nanometric pores. So, integrate nanomaterials and nanofabrication steps in the realization of such solar cells is of great interest.
In this work, the possible interactions of nanomaterials as Carbon Nanotubes (CNTs) and Nanoporous Alumina, as well as the integration of nanotechnology process such as Nanoimprint Lithography, have been investigated in the field of new gen solar cells. A thorough research on Carbon nanotubes (CNTs) has been carried out to realize semitransparent electrodes to be used as contacts in an organic solar cell. A “two temperature zone” Chemical Vapour Deposition (CVD) set-up is assembled to synthesize CNTs directly on top of Fluorine Doped Tin Oxide and standard glass. The transparency of the asprepared contacts is increased by the mean of a laser patterning technique. An additional technique used to deposit a very thin layer of Nickel, to enhance the conductivity of such semitransparent electrodes, is also presented.
The necessity of decreasing the roughness of the CNTs based electrodes, in order to prevent short circuits in organic solar cells, leads to the development of a spray deposition technique of nanotubes solutions on top of glass substrates. The use of different solutions, with and without the addition of surfactants, as well as the upgrade of the spray set-ups and the design of appropriate metal contacts for inverted organic P3HT:PCBM solar cells are shown.
The inverted architecture of bulk heterojunction solar cell is used also in combination with the Nanoimprint Lithography Technique (NILT): the creation of a pattern of nanometers size on the polymer surface, in order to realize a Photonic Crystal effect designed by optical simulations, is carried out through several technology obstacles, for each of which is given a proper solution.
Lastly, scaffolds of ordered Nanoporous Alumina, realized through the anodization of pure and evaporated Aluminium on glass, are used for the growth of perovskite active layers that are characterized by absorbance measurements
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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