1,720,974 research outputs found
Rhodococcal systematics: problems and developments
No full textVarious approaches that have been used in the development of a system of classification for the genus Rhodococcus are discussed. The application of chemotaxonomic, molecular systematic and numerical phenetic methods have greatly contributed to improvements in the systematics of rhodococci and related mycolic-acid containing actinomycetes. The genus currently encompasses twelve validly described species but improved diagnostic methods are needed to distinguish between them. In addition, evidence from 16S ribosomal RNA sequencing suggests that the genus is still heterogeneous.N
Effects of bottom electrodes on dielectric properties of ECR-PECVD Ta2O5 thin film
No full textThe effects of interfacial oxide layers formed on the bottom electrodes on the dielectric properties of Ta2O5 thin film were studied as one of the promising candidates as charge storage capacitor material for high-density dynamic random access memory (DRAM) devices. Ta2O5 thin film was prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) on various bottom electrodes, such as Si, Pt, TiN and W. The oxidation mechanism of the bottom electrode surfaces during the Ta2O5 film deposition was studied. Ta2O5 film started to be deposited after some incubation period (P), and the incubation period depended on the oxidation of the electrodes by the ECR oxygen plasma: P-W > P-Si > P-TiN > P-Pt. TiN and W bottom electrodes had interfacial oxide layers with SiO2-equivalent thickness (d*) of 0.9 nm and 2.1 nm, respectively, which were smaller than that of Si electrode (d(SiO2)*, = 4 nm).The authors acknowledge the support of RETCAM and Samsung Electronics for this work
Characterization of trimethylaluminum-N2O—He glow discharge in plasma-enhanced chemical vapor deposition of aluminum oxide films
No full textOn plasma-enhanced chemical vapor deposition of aluminium oxide films using trimethylaluminum (TMA) and N2O gases, optical emission spectroscopy (OES) analysis was performed to identify the ions and the radicals present in the glow discharge. A floating double probe was used to measure the plasma electron temperature and ion density. OES analysis of N2O gas-He plasma showed that N2O gas was dissociated into the form of NO and N-2. The He plasma was cooled by adding N2O and TMA. TMA was more effective in cooling the electron temperature than N2O gas. The radical concentration did not change with the mole fraction of the reative gases because of the cooling effect of the reactive gases, which affects the deposition rate. From the results of the floating double probe, it was found that r.f. power affects the plasma density rather than the mean electron energy. With an increase of r.f. power from 5 to 30 W in the He plasma, the plasma denisty of He plasma varied from 2.5 x 10(15) to 8 x 10(15) m(-3) and the mean electron energy was in the range of 4.1-3.5 eV
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
- …
