1,720,961 research outputs found
14N(α,p)17O nuclear reaction cross-section at 4.9-6.1 MeV
No full textThe 14N(α,p)17O nuclear reaction cross-section was measured in the energy range 4.9-6.1 MeV at the laboratory angle θ = 172° in order to apply ion beam analysis to the detection of N in metal oxynitride layers. Comparison between the new calculation and data in literature was performed, highlighting important discrepancies between the new results and old cross-section data. Application of the new calculations to a standard TiN film suggests improved accuracy for the data in the present work. © 2005 Elsevier B.V. All rights reserved.</p
Porphyrin-containing polyimide films deposited by high vacuum co-evaporation
No full textThin films of porphyrin-containing polyimide were produced by high vacuum co-evaporation of 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA), 3,3′-diaminodiphenyl sulfone (DDS) and 5,10,15,20 meso-tetraphenyl porphyrin (TPP). The films were characterized by FT-IR analysis, optical absorption and emission spectroscopy. FT-IR analysis shows that the film matrix is comprised of only unreacted monomers. The conversion of monomers to polyamic acid and the following condensation to polyimide were studied by curing the samples at temperatures up to 240 °C. The amount of polyamic acid increases from room temperature to 120 °C, while at higher temperature it starts to condense to polyimide. Optical analysis shows that TPP is incorporated in the film matrix and its chemical state is determined by the interaction with the monomers, polyamic acid and polyimide. After curing the TPP molecules are finely dispersed in the polyimide matrix and their absorption and fluorescence properties are wholly preserved
Digital quality control in cytology: Advantages and technical approach
No full textQuality control for pathologists and cytotechnicians in an urgent need, but it is delayed by the difficulties in the specimen management: the usual way for carrying out a quality control programme is to circulate specimens among participating individuals or institutions, collecting their diagnostic answers. Because cytologic specimens are not duplicable, sequential delivery of the same material is mandatory, with obvious temporal application
Optical sensing responses of tetraphenyl porphyrins toward alcohol vapours: A comparison between vacuum evaporated and spin-coated thin films
No full textThin porphyrin films for gas sensing applications are generally produced through chemical techniques. In this work thin solid films of three tetraphenyl porphyrins (H2TPP, Fe(TTP)Cl and CoTPP) have been deposited by means of vacuum evaporation technique. A preliminary characterization of the samples has been performed by means of Fourier Transform Infrared (FT-IR) and UV–vis absorption spectra. The behaviour of these samples exposed to methyl, ethyl and isopropyl alcohol vapours was investigated and compared to the behaviour of the samples deposited through spin coating technique. Elovich kinetics and Langmuir adsorption isotherms have been also studied. The comparison points out that the vacuum evaporated samples exhibit more pronounced and faster responses and higher sensitivity than spin-coated films
Digital storage of Pathology slides on the Internet: techniques and issues
No full textImage archives in Pathology have usually been based on selected, static images taken from the light microscope, chosen as representative of a whole case. The range of applications for such databases include some form of telediagnosis (in the form of static telepathology), tele-education, image processing and analysis, and quality control. This approach results in reasonably large archives, as often just some image is sufficient; however, some application may need to have more than the images available in this way, because there should be a total freedom in choosing observation fields.In particular, some form of telediagnosis needs the whole glass slide to be carried out successfully, and quality control too, due to its specific needs. Such needs include also a major difficuly that is delaying quality control in Pathology: the usual way for carrying out a quality control programme is to circulate specimens among participating individuals or institutions, collecting their diagnostic answers. Because cytologic specimens are not duplicable, sequential delivery of the same material is mandatory, with obvious temporal restrictions. For the above reasons, researchers are studying new ways of transforming the traditional glass slide used in Pathology into a digital form, in order to introduce the equivalent of digital PACS in histo- and cyto-pathology. However, such transformation is not easy, due to the large storage needed. The present paper discusses techniques and issues for the digital storage of Pathology slide
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
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