1,720,989 research outputs found
Recent progress in wearable fully textile chemical sensors
No full textIn the new era of Internet of Things, there is a great demand for the development of novel chemical wearable sensors, in particular, for personalized medical diagnostics with point-of-care devices. This paper provides an overview on the recent developments in this field, focusing on fully textile chemical sensors, i.e., sensors directly incorporated into a garment/fabric/ fiber. The recent results are summarized by grouping them in three broad categories according to their working principle: (i) electrochemical sensors; (ii) transistor-based sensors; and (iii) resistance-based sensors. Wearable chemical sensors can be used to detect external dangerous vapor/agents, or to control and monitor the concentration of specific compounds in biofluids for safety and healthcare applications. One of the main issues of such applications is sensor operation in a complex medium containing many interfering compounds. To this end, recent novel approaches to enhance the selectivity of fully textile wearable sensors are reviewed: enzyme-based approach, selective membrane, and a potentiodynamic method. Finally, a critical overview is given about the major open issues that have to be overcome in order to reach a high technology readiness level
DISPOSITIVO PER IL PRELIEVO E L'ANALISI DI UN FLUIDO BIOLOGICO
No full textDispositivo per il prelievo e l’analisi di un fluido biologico in micro-volumi; il dispositivo comprende un sensore, il quale è configurato per rilevare e/o quantificare un analita presente nel campione e/o una proprietà del campione.
Il dispositivo comprende, inoltre, un sistema di trasporto, il quale è configurato per il trasporto del campione dall’ambiente esterno (in particolare, da un essere vivente) al sensore e comprende un materiale fibroso, configurato per permettere la diffusione del fluido biologico attraverso sé stesso e presentante una porzione di analisi disposta in corrispondenza del sensore ed una porzione di trasporto dotata di una prima estremità che si aggetta all’esterno del dispositivo ed una seconda estremità in contatto con la porzione di analisi
Impact of environmentally friendly processing on polymer solar cells: Performance, thermal stability and morphological study by imaging techniques
No full textThe combination of mass-production compatible coating techniques and environmentally friendly solvents to process bulk heterojunction solar cells represents a key issue to scale up this technology. In this work we demonstrate that using a benchmark polymer HBG-1 blended with PC61BM, the replacement of a common chlorinated processing solvent (orthodichlorobenzene) with a non-chlorinated analogous (o-xylene) not only allows the fabrication of blade-coated bulk heterojunction devices with identical photovoltaic performance, but also determines a great enhancement of the resulting thermal stability. Thermal degradation tests were carried out in inert atmosphere, by keeping the solar cells onto a hot plate at 85 °C and monitoring their OPV performance. In parallel, the morphological changes of the active layers induced by thermal stress are investigated by combining two complementary light-based imaging techniques, laser scanning confocal and photocurrent microscopy, which offer the great advantage to simultaneously study on complete devices the blend morphology and the electrical properties, point-by-point, of the active layer even in regions unlikely accessible (e.g. the active area under the top electrode) using other techniques. As a result, we found that solar cells processed from a non-chlorinated based solvent, in comparison to an analogous reference system, exhibit a different evolution of the resulting BHJ morphology during thermal ageing, in perfect agreement with the corresponding photovoltaic responses
Nanoparticle gated semiconducting polymer for a new generation of electrochemical sensors
No full textThe development of portable and wearable sensors is of high importance in several fields such as point-of-care medical applications and environmental monitoring. Here we design, synthesize and exploit a new composite material based on Ag/AgCl nanoparticles and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate)) to fabricate a novel kind of sensor inspired by the organic electrochemical transistor (OECT). We are able to integrate an Ag/AgCl gate electrode into the semiconducting polymer in the form of NPs. As a consequence, our sensor combines an intrinsically amplified response with a simple two terminal electrical connection. Electrostatic Force Microscopy and Electrochemical Impedance Spectroscopy demonstrate the electronic coupling between the electrochemically active nanoparticles and the ionic charge gated semiconducting polymer, allowing to explain the sensor amplified transduction. The analytical signal is the current that flows in the composite polymer and its variation is directly proportional to the logarithm of Cl−concentration in the range 10−4to 1 M, with a limit of detection of 0.5 10−4M. Moreover, the device exhibits a shorter response time than the one of a conventional OECT endowed with an Ag/AgCl gate electrode. The sensor was used for in-situ detection of salinity in water and a textile device was obtained by depositing the composite material directly onto a cotton yarn for real-time sweat monitoring
SYSTEM AND METHOD FOR THE ASSESSMENT OF THE BIOMECHANICAL RISK FROM MANUAL HANDLING OF LOADS
No full textA system and method for assessing biomechanical risk in the context of handling heavy loads in workplaces. The system and method are applicable during a normal working activity for acquisitions lasting a work shift. The acquired data are then analysed in relation to regulatory references and international standards for the assessment of the biomechanical risk from manual handling of loads
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
A New Quinoxaline and Isoindigo Based Polymer as Donor Material for Solar Cells: Role of Ecofriendly Processing Solvents on the Device Efficiency and Stability
No full textA new semiconducting polymer based on two different electron deficient (quinoxaline and isoindigo) and electron rich (benzodithiophene) moieties is synthesized, characterized and used as donor material for photovoltaic devices. Blade-coated bulk heterojunction solar cells are fabricated in air by using chlorinated (o-dichlorobenzene) and nonchlorinated (o-xylene) solvents for the deposition of the active layer. The use of o-xylene allows a similar to 10% improvement of the device efficiency in comparison to the analogous system processed from o-dichlorobenzene. In addition, the evolution of the photovoltaic parameters of the resulting devices during thermal stress is monitored and compared, demonstrating a nearly identical resistance against temperature. The reported results not only highlight the promising properties of the new polymer in terms of environmental stability and compatibility with nonhalogenated solvents, but also show an easy and ecofriendly way to further improve the device performance without altering the corresponding thermal stability
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
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