1,721,003 research outputs found
Dataset for Germanium Micro-Gears as Vertically-Emitting Light Sources
No full textData underpinning the publication 'Germanium vertically light-emitting micro-gears generating orbital angular momentum' by Saito, Shinichi; Al-Attili, Abderlrahman Z.; Burt, Daniel; Li, Zuo; Higashitarumizu, Naoki; Gardes, Frederic; Oda, Katsuya; Ishikawa, Yasuhiko published in Optics Express.</span
Improving the mechanical, thermal and optical properties of biaxial and polyaxial Germanium suspended bridges towards a CMOS compatible light source
No full textGermanium (Ge) is a promising candidate for a CMOS compatible laser diode. This is due to its compatibility with Silicon (Si) and its ability to be converted into a direct band gap material by applying tensile strain. In particular uniaxial suspended Ge bridges have been extensively explored due to their ability to introduce high tensile strain. There have been two recent demonstrations of low-temperature optically-pumped lasing in these bridges but no room temperature operation accredit to insufficient strain and poor ther- mal management. In this thesis the merits of using biaxial and polyaxial suspended Ge bridges to move towards room temperature operation were outlined. Uniaxial bridges were compared with polyaxial bridges in terms of mechanical stress and thermal man- agement using Finite Element Modelling (FEM). The stress simulations revealed that polyaxial bridges suffer from extremely large corner stresses which prevent larger strain from being introduced compared with uniaxial bridges. Thermal simulations however re- veal that they are much less thermally sensitive than uniaxial bridges which may indicate lower optical losses. Bridges were fabricated and micro-Raman (μ-Raman) spectroscopy was used to validate the results of the simulations. We postulate that polyaxial bridges could offer many advantages over their uniaxial counterparts as potential laser devices. Using a novel geometric approach and finite element modelling (FEM) structures with improved strain homogeneity were designed and fabricated. μ-Raman spectroscopy was used to determine central strain values. Micro-PhotoLuminescence (μ-PL) was used to study the effects of the strain profiles on light emission; we report a PL enhancement of up to 3x by optimizing curvature at a strain value of 0.5% biaxial strain. This geometric approach offers opportunity for enhancing the light emission in Ge towards developing a practical on chip light source. Finally the thesis concludes with a novel simple elliptical design for polyaxial bridges. This design further reduced the corner stresses in polyaxial bridges by 20%, even without optimization. A large 1.11% strain was achieved in a Ge on Si stack as confirmed by μ-Raman and FEM. Furthermore an optical cavity was introduced in this deign with no extra complex fabrication, this was confirmed using μ-PL and Finite Difference Time Domain (FDTD) simulations
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
Smaller Collections of inscriptions in OCIANA
Full text linkThis pdf contains all of the Taymanitic inscriptions from the OCIANA databas
OCIANA Safaitic Corpus
Full text linkThis pdf contains all of the Safaitic inscriptions contained within the OCIANA database
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
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