125,434 research outputs found
Investigation of a novel silicon-on-insulator Rib-Slot photonic sensor based on the vernier effect and operating at 3.8 µm
No full textIn this paper, we present the theoretical investigation of photonic sensors based on Vernier effect with two cascade-coupled ring resonators in silicon on insulator technology. The photonic chip utilizes rib and slot waveguides designed to operate at 3.8 µm mid infrared wavelength, where a number of harmful gases, chemical and biochemical analytes are spectroscopically accessible. A rigorous algorithmic procedure has been implemented for the design of such devices and novel technological solutions have been proposed according to very recent experimental results. The rib-slot sensor architecture can exhibit wavelength sensitivities as high as 20.6 µm/RIU and limits of detection for homogeneous sensing as low as 3.675 × 10−4 RIU
A generalized approach for design of photonic gas sensors based on Vernier effect in mid-IR
No full textIn this paper a generalized approach for modeling and design of photonic sensors based on Vernier effect
is presented. Design criteria of integrated optical architectures based on multiple ring resonators are
found, customized as a function of a specific gas to be monitored. Very efficient performance has been
demonstrated in mid-IR operative wavelength range. Sensitivities of the order of 105 nm/RIU and limits of detection as low as 10^−5 RIU allow detecting very small traces of methane and ethane in air
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Aurora B: A New Prognostic Marker and Therapeutic Target in Cancer
No full textAurora B is a serine-threonine kinase belonging to the highly conserved Aurora family of mitotic kinases. Aurora B is a chromosomal passenger protein involved in chromosome segregation, spindle-checkpoint, and cytokinesis. Alteration of each of these steps could induce aneuploidy, one of main features, and driving force of cancer progression. The overexpression of Aurora B has been observed in several tumor types, and has been linked with a poor prognosis of cancer patients. In this review we will focus on the role of Aurora B in cancer development, its role as a prognostic marker, and the clinical outcome of recently developed Aurora(s) inhibitors
Cascaded ring resonator and Mach-Zehnder interferometer with a Sagnac loop for Vernier-effect refractive index sensing
No full texttIn this paper, we propose a novel photonic integrated sensor characterized by the cascade of a ringresonator (RR) and a Mach-Zehnder interferometer (MZI) architecture with a Sagnac loop (i.e., RR-MZI-Sagnac). We present the modelling and detailed guidelines for the design of such devices that are assumedto be fabricated on complementary metal-oxide semiconductor (CMOS) compatible silicon-on-insulator(SOI) platforms. Ultra-high refractive index (RI) sensing performance such as wavelength sensitivitieslarger than 2.5 × 103m/RIU (RI unit) and limits of detection (LOD) of 1 × 10−8RIU can be achieved byemploying the Vernier effect in the near-infrared (NIR), around the wavelength of 1.55 m. Furthermore,we theoretically demonstrate that the novel RR-MZI-Sagnac Vernier devices can operate better than themost performing state-of-the-art Vernier sensors characterized by cascaded RR and MZI (RR-MZI). Infact, an operating bandwidth that is half than that requested by the RR-MZI devices is exhibited whenbalanced MZIs are designed in both configurations, still preserving similar RI sensing performance. Alter-natively, double RI sensing performance can be achieved by RR-MZI-Sagnac Vernier sensors with respectto RR-MZI devices when unbalanced MZIs are considered in both the Vernier configurations, exhibitingthe same operating bandwidths. Finally, simulations reveal that ammonia (NH3) concentrations in the0–30,000 ppm range and carbon dioxide (CO2) traces lower than 5,000 ppm can be detected in deionizedwater and air, respectively
Rules of the evalutation of the environmental and technological quality of the urban spaces
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