1,720,956 research outputs found
Direct laser interference patterning of stainless steel by ultrashort pulses for antibacterial surfaces
Full text linkDirect Laser Interference Patterning (DLIP) with ultrashort pulses was exploited to produce tailored periodic sub-micrometer structures on stainless steel surfaces to reduce bacterial attachment and retention. Laser pulses with wavelength 1030 nm and duration 8 ps were employed to form a two-beam line interference pattern that was applied in a two-pass strategy to produce fine cross-wise surface structures with a period of ~ 850 nm and a depth of ~ 500 nm. The laser setup and process parameters were selected based on a simple theoretical model of the resulting interference pattern and ablation depth to limit the number of contact points available for bacterial cells with dimensions 500–2000 nm. Periodic ‘cones’ and ‘holes’ were produced covering areas of 250 mm2 with the same interference pattern by exploiting the dependence of laser-induced periodic surface structures on polarization. Cones and holes yielded reductions in E. coli retention of 99.8% and 99.4%, respectively, and S. aureus retention of 70.6% and 79.1%, respectively, after two hours immersion in bacterial solution compared to reference samples. Such reductions achieved over large surface areas suggests that this approach is appropriate for upscaling and high throughput production of antibacterial metallic surfaces in the food and healthcare industries
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
Insight into replication effectiveness of laser-textured micro and nanoscale morphology by injection molding
Full text linkDetailed analysis and characterization of injection-molded polypropylene (PP) specimens produced with laser-textured molds has been performed. Ultrashort pulsed laser surface structuring was exploited to produce sub-micrometric surface features on injection molds over areas of 2400 mm2, including two-dimensional hole and cone arrays, and ridges parallel and perpendicular to the injection direction. Replication effectiveness was evaluated in terms of surface roughness parameters, Filling Volume Fraction (FVF) and Power Spectral Density (PSD), after which detailed comparison of the topography in the same region on plastic samples and molds was performed. A scatterometry setup was employed based on optical diffraction of a probe laser beam to assess replication fidelity over the entire surface of each PP sample with a measurement technique suitable for optimization and quality control in an industrial production environment. Of the tested surface morphologies, greatest replication effectiveness was achieved with LIPSS oriented parallel to the injection direction, where the arithmetic mean height of plastic samples (Sa = 37 ± 4 nm) was 97 % of the corresponding value of the mold (Sa = 38 ± 6 nm), while the average FVF was 86 ± 9 % and the PSD indicated ripple-like features with a spacing of λ≃0.9 μm. Direct comparison of the topography in selected regions highlighted local variability in the transfer effectiveness of individual surface features. The investigation demonstrated that micro and nanoscale morphology can effectively be transferred via injection molding over large areas relevant to industrial applications, while careful attention must be paid to the size and nature of defects in relation to the specific functional surface under consideration
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
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
- …
