1,721,018 research outputs found
Routine fabrication of reduced graphene oxide microarray devices via all solution processing
No full textA method for the routine fabrication of graphene (reduced graphene oxide (r-GO)) based devices is reported. We describe a solution-based technique for the fabrication of the devices on alternative substrates and subsequent on-substrate processing of graphene oxide into reduced graphene oxide. As sensor platform we mainly used interdigitated gold electrodes forming microarray structures on glass substrates. Graphene oxide was site-specifically deposited onto microelectrode arrays by dielectrophoresis followed by a solution-based reduction of graphene oxide with L-ascorbic acid. In order to test the r-GO sensor stability and performance, impedance spectroscopy was used. The optimized all solution processed fabrication provides an attractive fabrication route for robust r-GO microarray devices in a flexible, scalable and cost-effective approach. Schematics for a microarray chip based on reduced graphene oxide
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
Self-Assembled Liquid-Gated Zinc Oxide Nanowire Transistors : Fabrication and Sensing Operation
No full textThis thesis aims at the site-specific realization of self-assembled field-effect transistors (FETs) based on semiconducting Zinc oxide NWs and their application towards chemical and bio-sensing in liquid medium. At first, a solution based growth method for hierarchical ZnO nanostructures was devised in order to achieve synthesis of high quality ZnO NWs. This solution based growth method was then deployed for the growth of NWs from preferred sites on a substrate. In order to make a transistor, microelectrode pairs prewritten on a Si/SiO2 chip (4mm◊4mm) using standard photolithography procedure served as growth sites and also formed source and drain terminals. The NWs bridging these "source" and "drain" electrodes formed the transistor channel. The procedure here yields ZnO NWs in up to 100 percent of the positions available for growth. The site-specific self-assembled fabrication of ZnO NW FETs was evaluated in terms of scalability and applications. The procedure was extended from 4mm◊4mm silicon chips to large area silicon wafers (80mm◊80mm) and flexible substrates of Kapton polyimide of the same size. On the large area substrates this procedure yields ZnO NWs in up to 80 percent of the positions available for growth, which can be bettered. Furthermore, the method was also employed to fabricate ZnO NW FETs in situ in a microfluidic channel. For this purpose the precursor solution was let to flow on to the microelectrode pairs with the help of microfluidic channels assembled on top of the substrate. The substrate was heated locally under the microelectrode pairs to stimulate the NW growth. Thus a solution-based self-assembled fabrication of NW FETs was achieved locally inside a microfluidic channel. Microfluidic channels were made of silicon nitride (Si3N4) on top of Si/SiO2 chips and facilitated the characterization of FETs in liquid medium. Alternatively, microfluidic channels made of polydimethylsiloxane (PDMS) were used for characterization of transistor devices in liquids. In order to deploy FETs in liquids, the back-gate is replaced by a reference electrode (Ag/AgCl) and the potential is applied through a liquid surrounding the transistor channel (ZnO NW). The liquid surrounding the ZnO NW creates an electrochemical double layer (EDL) on the NW surface which in turn gives rise to the gate capacitance. The resulting gating effect can be used to modulate the NW conductance depending on the voltage applied through the liquid. The ZnO NW transistors showed a current modulation of up to 6 orders of magnitude, high field-effect mobilities (around 1.85 cm2/Vs) and sub-threshold slopes as low as 105 mV/decade. This is the first demonstration of liquid-gated FETs using ZnO NWs. The liquid-gated FETs are used as a basic device for further sensing trials in liquids. For this purpose, the FETs were functionalized with receptor molecules. These so called ion-selective FETs (ISFETs) were demonstrated as functional pH sensors for liquids with pH values from 6 to 10. The NWs functionalized with analyte-sensitive molecules on their surface are influenced electrically by the presence of analytes in the surrounding liquid. Any change in the amount of analyte present in the surrounding liquid is thus reflected in the electrical transport characteristics of the FET. 3-aminopropyltriethoxysilane (3-APTES) molecules were used to functionalize the ZnO NWs in order to construct the pH sensors. Subsequently, the realization of a biosensor based on ZnO NW transistors is demonstrated. Label-free direct detection of urea molecules was carried out from a solution of urea in buffer. ZnO NWs were electrochemically functionalized with the enzyme urease incorporated into an electro-polymerized polypyrrole matrix. Urease molecules act as specific receptors for urea molecules and catalyze an enzymatic reaction. This reaction causes a pH change in the vicinity of NWs, which is reflected in the field-effect characteristics of transistor. The performance of liquid-gated ZnO NW FETs used as chemical and biological sensor can be further improved by employing a metal gate in liquid medium. This was established by fabricating liquid gated metal-semiconductor FET (MESFET) based on ZnO NWs. ZnO NWs were decorated with metal nanoparticles (NPs) by using an electrochemical deposition method. The NPs were then used as metal gate and devices were characterized by applying a gate voltage on the NPs through the liquid. The realization of metal-semiconductor gate in liquids considerably improved the field-effect characteristics of liquid-gated FETs based on ZnO NWs. The realization of high performance liquid-gated transistors based on ZnO NWs thus constitutes a suitable platform for label-free detection of biomolecules and shows promise for future applications in chemical analysis and medical diagnostics.LSE
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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