Study of novel Love mode surface acoustic wave filters

Novel Love mode filters based on ZnO and SiO<sub>2</sub>/90° rotated ST-cut quartz crystal structure were fabricated. A comprehensive study was carried out to show the capabilities of such filters. The periodicity of the fingers is 50 μm and the thickness of the SiO<sub>2</sub> and ZnO layers ranges from 0.2 to 7.2 μm. Electromechanical coupling coefficient, capacitance per unit wavelengths of finger pairs and temperature coefficient of frequency are studied in terms of thickness of the wave-guiding layers

Headache in history and the arts. The artemicranica project

The project ‘‘ARTeMICRANICA’’ originates from the exhibition of Giorgio De Chirico ‘ARTeMICRANIA. Opere e parole tra mal di testa e metafisica.’’ held in Rome in September 2003 at the XI Congress of the International Headache Society / IHC 2003

Love mode SAW sensors with ZnO layer operating in gas and liquid media

Novel layered surface acoustic wave (SAW) sensors, based on a ZnO/90° rotated ST-cut quartz crystal structure, were fabricated. They were employed for liquid and gas sensing applications. Their mass detection limit in liquid media is as low as 100 pg/cm2. Furthermore, these sensors are able to sense oxygen gas concentrations as low as 0.2 ppm in nitrogen gas

Nano-scale reservoir computing

This work describes preliminary steps towards nano-scale reservoir computing using quantum dots. Our research has focused on the development of an accumulator-based sensing system that reacts to changes in the environment, as well as the development of a software simulation. The investigated systems generate nonlinear responses to inputs that make them suitable for a physical implementation of a neural network. This development will enable miniaturisation of the neurons to the molecular level, leading to a range of applications including monitoring of changes in materials or structures. The system is based around the optical properties of quantum dots. The paper will report on experimental work on systems using Cadmium Selenide (CdSe) quantum dots and on the various methods to render the systems sensitive to pH, redox potential or specific ion concentration. Once the quantum dot-based systems are rendered sensitive to these triggers they can provide a distributed array that can monitor and transmit information on changes within the material.Comment: 8 pages, 9 figures, accepted for publication in Nano Communication Networks, http://www.journals.elsevier.com/nano-communication-networks/. An earlier version was presented at the 3rd IEEE International Workshop on Molecular and Nanoscale Communications (IEEE MoNaCom 2013

A room temperature polyaniline nanofibre hydrogen gas sensor

Electro-conductive polyaniline (PANI) nanofiber based surface acoustic wave (SAW) gas sensors have been investigated with hydrogen (H 2) gas. A template-free, rapidly mixed method was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. The nanofibers were deposited onto a layered ZnO/64° YX LiNbO3 SAW transducer for gas sensing applications. The novel sensor was exposed to various concentrations of H2 gas at room temperature. The sensor response, defined as the relative variation in operating frequency of oscillation due to the introduction of the gas, was 3.04 kHz towards a 1% H2 concentration. A relatively fast response time of 8 sec and a recovery time of 60 sec with good repeatability were observed at room temperature. Due to room temperature operation, the novel gas sensor is promising for environmental and industrial applications

Characterization and testing of Pt/TiO2/SiC thin film layered structure for gas sensing

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Nanostructured molybdenum oxide gas sensors

In this paper, we present a surface acoustic wave (SAW) gas sensor based on nano-structured molybdenum oxide (MoOx) thin film. The film was deposited onto a 36° YX LiTaO3 SAW transducer, with an operating frequency of approximately 103 MHz, by thermal evaporation. The nanostructured MoOx film consists of connected nanorods with diameters of less than 100 nm. We compared devices with MoOx deposited by RF sputtering and thermal evaporation and found those with evaporated films have response that are an order of magnitude larger

A room temperature polyaniline nanofiber hydrogen gas sensor

Abstract—Electro-conductive polyaniline (PANI) nanofiber based Surface Acoustic Wave (SAW) gas sensors have been investigated with hydrogen (H2) gas. A template-free, rapidly mixed method was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. The nanofibers were deposited onto a layered ZnO/64º YX LiNbO3 SAW transducer for gas sensing applications. The novel sensor was exposed to various concentrations of H2 gas at room temperature. The sensor response, defined as the relative variation in operating frequency of oscillation due to the introduction of the gas, was 3.04 kHz towards a 1 % H2 concentration. A relatively fast response time of 8 sec and a recovery time of 60 sec with good repeatability were observed at room temperature. Due to room temperature operation, the novel gas sensor is promising for environmental and industrial applications. I

Structure and Transport in Coatings from Multiscale Computed Tomography of Coatings-New Perspectives for Eelectrochemical Impedance Spectroscopy Modeling?

Computed Tomography (CT) is an approach that has been extensively applied in many areas of science from understanding structures in living organisms to materials science. In materials science, the study of structures within coatings presents challenges on at least two different levels. First, the structure of the coatings needs to be understood from the atomic scale, where dissolution reactions begin, up to length scales which cover the aggregation of inhibitors and other additives, which take place at ∼10−5 m, i.e. 4 to 5 orders of magnitude. CT is a favourable imaging technique since it allows multiscale information to be obtained non-destructively down to tens of nanometres. In this study X-ray absorption contrast imaging has been used to examine structures created using strontium chromate (SrCrO4) particles embedded in an epoxy film. It has been found that SrCrO4 particles can form clusters that extend a few hundred microns in the plane of the film, span the thickness of the film and have fractal characteristics. There are also volumes of low density epoxy of similar sizes and characteristics to the SrCrO4 clusters. The SrCrO4 clusters have a strong influence on the leaching behaviour since the release changes with time. Initially, leaching is controlled by direct dissolution but, as the clusters dissolve, the release is dominated by the fractal dimension of the cluster. The dissolved clusters leave behind voids filled with electrolyte that provide alternative transport pathways for corrosive ions through the polymer. In this paper, the nature of these clusters will be reviewed and the implication for transport properties and electrochemical assessment will be explored

ZVAX : a microservice reference architecture for nation-scale pandemic management

Domain-specific Microservice Reference Architectures (MSRA) have become relevant study objects in software technology. They facilitate the technical evaluation of service designs, compositions patterns and deployment configurations in realistic operational practice. Current knowledge about MSRA is predominantly confined to business domains with modest numbers of users per application. Due to the ongoing massive digital transformation of society, people-related online services in e-government, e-health and similar domains must be designed to be highly scalable at entire nation level at affordable infrastructure cost. With ZVAX, we present such a service in the e-health domain. Specifically, the ZVAX implementation adheres to an MSRA for pandemic-related processes such as vaccination registration and passenger locator form submission, with emphasis on selectable levels of privacy. We argue that ZVAX is valuable as study object for the training of software engineers and for the debate on arbitrary government-to-people services at scale