1,720,958 research outputs found
Computational Models for The Numerical Simulation of Voltage Operated Channels in Nano--Bio--Electronics
No full textElectrochemical Modeling and Characterization of Voltage Operated Channels in Nano-Bio Electronics
No full textIn this article, the electrical characterization of Voltage Operated ionic Channels (VOCs) in Nano-
Bio-Electronics applications is carried out. This is one of the relevant steps towards a multi-physics
description of hybrid bio-electronical devices such as bio-chips. Electrochemical ionic transport phenomena
are properly modeled by a Poisson-Nernst-Planck partial differential system of nonlinearly
coupled equations, while suitable functional iteration techniques for problem decoupling and finite
element methods for discretization are proposed and discussed. Extensive numerical simulations of
single species VOCs transporting K+ ions are performed to consistently derive an electrical equivalent
representation of the channel and to quantitatively describe its interaction with an external
measurement device under several working conditions
Computational Modeling and Simulation of Complex Systems in Bio-Electronics
No full textIn this article, we discuss the mathematical and
computational framework required to develop a generalpurpose
simulation tool for bio-electronic applications.
Electrochemical and fluid-mechanical transport of substances,
chemical reactions and electrical transduction of
biological signals are described through the coupled use of
systems of partial and ordinary differential equations (PDEs
and ODEs). Functional iteration techniques for system decoupling
and mixed-hybridized finite element discretization
methods are proposed and validated in the simulation of realistic
problems in Electrophysiology and Biochemistr
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
Computational models in nano-bio-electronics: simulation of ionic transport in voltage operated channels
No full textIn this article, a novel mathematical and computational model is proposed for the numerical simulation
of Voltage Operated ionic Channels (VOC) in Nano-bio-electronics applications. This is a first
step towards a multi-physics description of hybrid bio-electronical devices such as bio-chips. The
model consists of a coupled system of nonlinear partial differential equations, comprising a Poisson-
Nernst-Planck system to account for electro-chemical phenomena, and a Navier-Stokes system to
account for fluid-mechanical phenomena. Suitable functional iteration techniques for problem decoupling
and finite element methods for discretization are proposed and discussed. Numerical results
on realistic VOCs illustrate the validity of the model and its accuracy by comparison with relevant
computed channel equivalent electrical parameters with measured data
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