1,720,958 research outputs found
Non-equilibrium formation of the cubic Pn3m phase in a monoolein/water system
No full textTime-resolved small-angle X-ray diffraction experiments have been carried out to
investigate the transformation from the cubic gyroid Ia3d to the cubic diamond Pn3m phase.
The transition was induced by rapid addition of water to a monoolein/water system changing
the initial water concentration of 26% w/w to excess of water conditions. The transformation
proceeds in two steps: at the beginning, the two cubic mesophases have a strongly differing
lipid/water composition and are accompanied by an intermediate phase. This phase vanishes
as the ratio of cell parameters exceeds 1.50. Thereafter, the transition continues by a direct
nearly isoareal transformation of the cubic minimal surfaces. Lateral area per lipid molecule,
molecular shape and principle curvatures are about the same in this regime
Sugar-induced stabilization of monoolein Pn3m bicontinuous cubic phase during dehydration
No full textEffect of Temperature-Pressure Cycles on Structural Properties of Expoxy Based Composites for Printed Circuit Boards (PCB) Applications
No full text
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
Parasitic Coupling Effects in Multimode Buried Channel Waveguides Arrays for O-PCB Interconnects
No full textThe use of buried channel waveguides in optical printed circuits boards (O-PCB) offers the possibility of overcoming some problems and limitations encountered in high-frequency electrical interconnects. Although the use of optical waveguides reduces significantly crosstalk and electromagnetic interferences, parasitic coupling effects between the buried channels may appear when waveguide arrays are realized. In this paper, we analyze theoretically and experimentally the conditions inducing crosstalk effects in a multimode array, realized by means of a conventional photolithographic patterning technique. In particular, the results show how the common configuration used to pattern an array of optical waveguides produces a parasitic slab waveguide close to the core channels, accounting for a substantial increase of the coupling effects
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
Defect analysis on optical waveguide arrays by synchrotron radiation microtomography
Full text linkIn recent years, great attention has been devoted to the study
and realization of polymeric optical waveguides embedded in printed
circuit boards due to the increasing need of transferring large amounts
of data at high speed within computer and telecommunication devices.
Nonuniform microstructural defects that can be induced during the manufacturing
process can dramatically influence the waveguide performance.
The synchrotron radiation computed microtomography technique was
used to obtain 3-D microstructural information, specifically to observe
small defects, such as porosities, in a nondestructive way. Porosity level
and pore size range were evaluated
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
- …
