1,720,973 research outputs found
Low cost thin-film transistor nanoribbon sensors for detection of proteins using a miniature bead-based enzyme-linked immunosorbent assay (elisa)
No full textWe demonstrate a low cost thin-film transistor (TFT) nanoribbon sensor for measuring enzyme-substrate reactions. The sensor is used to measure the inflammatory biomarker C-reactive protein (CRP) in human serum using a miniature bead-based Enzyme-Linked Immunosorbent Assay (ELISA) with the sensor measuring pH. Rather than binding antibodies directly to the sensor surface, a magnetic bead-based ELISA was used. This keeps the functionalization steps and capture moieties away from the sensor surface, increasing the binding sites and improving speed and sensitivity. The ability to sense proteins in physiological buffer via enzyme activity overcomes the Debye length limitation associated with nano-biosensors
Low noise vacuum MEMS closed-loop accelerometer using sixth-order multi-feedback loops and local resonator sigma-delta modulator
No full textThis paper reports on the design, implementation of a novel sixth-order sigma-delta modulator (ΣΔM) MEMS closed-loop accelerometer with extended bandwidth in a vacuum environment (~0.5Torr), which can coexist on a single die (or package) with other sensors requiring vacuum packaging. The fully differential accelerometer sensing element with a large proof mass (4×7mm2) was designed and fabricated on a Silicon-on-Insulator (SOI) wafer with 50μm-thick structural layer. Four electronic integrators were cascaded with the sensing element for high-order noise shaping ability. The local feedback paths created a local resonator producing a notch to further suppress the total in-band quantization noise. Measurement results show the overall noise floor achieved was -120dBg/√Hz, which is equivalent to a noise acceleration value of 1.2μg/√Hz in a 500Hz bandwidth; the scale factor was 950mV/g for input accelerations up to ±6g
Effects of surface passivation on top-down ZnO nanowire transistors
No full textWe fabricated unpassivated and passivated zinc oxide (ZnO) nanowire field effect transistors (NWFETs) using conventional top-down method of remote plasma atomic layer deposition and anisotropic dry etch. This paper investigates the effect of Al2O3 passivation on the electrical characteristics of the ZnO NWFETs. Measured unpassivated ZnO NWFETs show a threshold voltage of 6.5 V, drain current on/off ratio of 106 and field effect mobility of 31.4 cm2/Vs. Passivated ZnO NWFETs demonstrate threshold voltage shift to −10 V, drain current on/off ratio of 104 and improvement of mobility of 35.5 cm2/Vs. The passivated device results indicate suitability for biosensing applications
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
Effects of surface passivation on top-down ZnO nanowire transistors
No full textWe fabricated unpassivated and passivated zinc oxide (ZnO) nanowire field effect transistors (NWFETs) using conventional top-down method of remote plasma atomic layer deposition and anisotropic dry etch. This paper investigates the effect of Al2O3 passivation on the electrical characteristics of the ZnO NWFETs. Measured unpassivated ZnO NWFETs show a threshold voltage of 6.5 V, drain current on/off ratio of 106 and field effect mobility of 31.4 cm2/V s. Passivated ZnO NWFETs demonstrate threshold voltage shift to -10 V, drain current on/off ratio of 104 and improvement of mobility of 35.5 cm2/V s. The passivated device results indicate suitability for biosensing applications
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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