1,720,955 research outputs found
Responsive, 3d Electronics Enabled by Liquid Crystal Elastomer Substrates
No full textDue to copyright restrictions and/or publisher's policy full text access from Treasures at UT Dallas is limited to current UTD affiliates (use the provided Link to Article).Supplementary material is available on publisher's website. Use the DOI link below.Traditional electronic devices are rigid, planar, and mechanically static. The combination of traditional electronic materials and responsive polymer substrates is of significant interest to provide opportunities to replace conventional electronic devices with stretchable, 3D, and responsive electronics. Liquid crystal elastomers (LCEs) are well suited to function as such dynamic substrates because of their large strain, reversible stimulus response that can be controlled through directed self-assembly of molecular order. Here, we discuss using LCEs as substrates for electronic devices that are flat during processing but then morph into controlled 3D structures. We design and demonstrate processes for a variety of electronic devices on LCEs including deformation-tolerant conducting traces and capacitors and cold temperature-responsive antennas. For example, patterning twisted nematic orientation within the substrate can be used to create helical electronic devices that stretch up to 100% with less than 2% change in resistance or capacitance. Moreover, we discuss self-morphing LCE antennas which can dynamically change the operating frequency from 2.7 GHz (room temperature) to 3.3 GHz (-65 °C). We envision applications for these 3D, responsive devices in wearable or implantable electronics and in cold-chain monitoring radio frequency identification sensors. ©2019 American Chemical Society.National Science Foundation under grant nos. 1711383, NSF ECCS 1711467 and NSF EFRI 1332348; Defense Advanced Research Projects Agency (DARPA) under contract no. 140D6318C0097.Erik Jonsson School of Engineering and Computer Scienc
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Liquid Crystal Elastomers as a Material for Neural Interfaces
No full textImplantable microelectrode development aims to enable functional restoration in patients who
suffer paralysis, strokes, limb loss, or neurodegenerative disease. However, the chronic reliability
of such neural interfaces is compromised, in part, by the body’s own foreign body response (FBR),
leading to localized astrogliosis and fibrotic encapsulation of the device. These factors can lead to
accelerated mechanical/electrical device failure and/or neuronal dieback at the site of implantation.
The use of polymer substrates for neural interfaces has gained traction due to advantages such as
mechanical flexibility and compliancy, which have been shown to reduce FBR-induced
encapsulation when compared to the current state-of-the-art substrates (i.e., silicon). Liquid Crystal
Elastomers (LCEs), a subclass of liquid crystal polymers (LCPs), exhibit a low modulus and can
be fabricated into shapes which exhibit a high degree of flexibility. Furthermore, this class of
polymers can be molecularly aligned to enable programmable and reversible shape change when
exposed to a stimulus such as heat, light, or specific solvent. This approach potentially enables the
controlled deployment of small recording or stimulation sites to regions beyond that of the FBR induced encapsulation (50 – 100 µm). The overarching goal of this project is to demonstrate the
feasibility of using LCE-based implantable electrode arrays in chronic cortical recording
applications. First, we evaluate cytotoxicity, functional neurotoxicity, and manufacturability of
LCE as a substrate material for novel neural interfaces in vitro. Second, we evaluate the
electrochemical stability of LCE as an insulating substrate in vitro. Finally, we evaluate the
electrochemical stability and recording capability of LCE as an insulating substrate and deployable
device in vivo
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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