416 research outputs found

    Validation of a 1H-NMR Spectroscopy Quantitative Method to Quantify Trimethylamine Content and K -Index Value in Different Species of Fish

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    The chemical analysis that is frequently employed for the evaluation of the freshness of fish includes (i) the quantification of trimethylamine (TMA) and (ii) the estimation of the K-Index, based on the ratio between the concentrations of adenosine triphosphate (ATP) and its breakdown products. TMA is quantified using a colorimetric reference method (AOAC), while the K-Index is usually determined by HPLC. The present work proposes a method for the above freshness biomarkers based on HR H-1-NMR as an alternative method able to assess both indexes simultaneously on aqueous fish extracts. To validate the proposed H-1-NMR method, a large set of validation checks has been addressed, such as accuracy, precision, specificity, limits of detection, linearity, and range of linearity and quantification according to EuroChem guidelines. The results show that the methodology satisfies all the validation requirements at the same level as the most frequently used methods, with the advantage of being faster and more repeatable, avoiding the use of solvents, such as toluene and formaldehyde, or dangerous reagents such as picric acid

    A Comparison of Readability in Science-Based Texts: Implications for Elementary Teachers

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    Science curriculum standards were mapped onto various texts (literacy readers, trade books, online articles). Statistical analyses highlighted the inconsistencies among readability formulae for Grades 2–6 levels of the standards. There was a lack of correlation among the readability measures, and also when comparing different text sources. Online texts were the most disparate with respect to text difficulty. These findings suggest implications for elementary teachers to support students who learn through reading online, science-based resources. As 21st-century learning through multi-modal literacies evolves, the readability of online, content-based text should be evaluated to ensure accessibility to all readers

    Advanced turboprop multidisciplinary design and optimization within agile project

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    The present paper deals with the design, analysis and optimization of a 90 passengers turboprop aircraft with a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The prescribed aircraft is one of the use cases of the AGILE European project, aiming to provide a 3rd generation of multidisciplinary design and optimization chain, following the collaborative and remote aircraft design paradigm, through an heterogenous team of experts. The multidisciplinary aircraft design analysis is set-up involving tools provided by AGILE partners distributed worldwide and run locally from partners side. A complete design of experiment, focused on wing planform variables, is performed to build response surfaces suitable for optimization purposes. The goal of the optimization is the direct operating cost, subject to wing design variables and top-level aircraft requirements

    Study on ultra-structural effects caused by Onion yellow dwarf virus infection in ‘Rossa di Tropea’ onion bulb by means of magnetic resonance imaging

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    \u2018Rossa di Tropea\u2019 onion is a particular pink/red coloured onion cultivated in Calabria region (Southern Italy), representing one of the Italian most important vegetable crops granted with Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI) trademarks. This local cultivar is characterised by a high nutraceutical compounds content showing anti-inflammatory, anti-cholesterol, anticancer and antioxidant properties. As all vegetable crops and Allium spp., \u2018Rossa di Tropea\u2019 onion is affected by several viruses. Among these, the species Onion yellow dwarf virus (OYDV, genus Potyvirus, family Potyviridae), represents the most limiting biotic stress, inducing severe symptoms. OYDV effect on tissues architecture in whole bulbs was investigated using magnetic resonance microimaging (MRI) technique, which allows the interior of samples to be imaged non-invasively and non-destructively and yields quantitative information on physico-chemical parameters describing water mobility (T1 and T2 relaxation times). The use of such tool allowed to determine how OYDV alters plant physiology by inducing water accumulation in bulb tissues as well as causing ultra-structural modifications of cell wall, highlighted by MRI. All these effects resulted in an increase of free water in plant tissues, and consequently relevant water losses during post-harvest storage, seriously affecting bulb quality, marketability and shelf life

    A model-based rams estimation methodology for innovative aircraft on-board systems supporting mdo applications

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    The reduction of aircraft operating costs is one of the most important objectives addressed by aeronautical manufactures and research centers in the last decades. In order to reach this objective, one of the current ways is to develop innovative on-board system architectures, which can bring to lower fuel and maintenance costs. The development and optimization of these new aircraft on-board systems can be addressed through a Multidisciplinary Design Optimization (MDO) approach, which involves different disciplines. One relevant discipline in this MDO problem is Reliability, Availability, Maintainability and Safety (RAMS), which allows the assessment of the reliability and safety of aircraft systems. Indeed the development of innovative systems cannot comply with only performance requirements, but also with reliability and safety constraints. Therefore, the RAMS discipline plays an important role in the development of innovative on-board systems. In the last years, different RAMS models and methods have been defined, considering both conventional and innovative architectures. However, most of them rely on a document-based approach, which makes difficult and time consuming the use of information gained through their analysis to improve system architectures. On the contrary, a model-based approach would make easier and more accessible the study of systems reliability and safety, as explained in several studies. Model Based Systems Engineering (MBSE) is an emerging approach that is mainly used for the design of complex systems. However, only a few studies propose this approach for the evaluation of system safety and reliability. The aim of this paper is therefore to propose a MBSE approach for model-based RAMS evaluations. The paper demonstrates that RAMS models can be developed to quickly and more effectively assess the reliability and safety of conventional and innovative on-board system architectures. In addition, further activities for the integration of the model-based RAMS methodology within MDO processes are described in the paper

    ASSESSMENT OF NEW TECHNOLOGIES IN A MULTI-DISCIPLINARY DESIGN ANALYSIS AND OPTIMIZATION ENVIRONMENT INCLUDING RAMS AND COST DISCIPLINES

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    The aim of the present paper is to assess the effect of new technologies on the whole aircraft product including its costs, reliability and maintainability characteristics. Several studies have been conducted dealing with the preliminary evaluation of Reliability, Availability, Maintainability and Safety (RAMS) of conventional aircraft. They provide a very effective method to preliminary estimate RAMS characteristics but their employment is not completely suitable for the analysis of unconventional configurations adopting new technologies. This paper aims at evaluating how the aircraft costs and RAMS characteristics are affected by new structures material, natural laminar flow wing technology and unconventional actuator system (electro-hydrostatic actuators), hence an update of the state of the art models is needed. This evaluation is performed by means of a setup and execution of a Multidisciplinary Design Analysis and Optimization (MDAO) workflow. The MDAO environment includes the aircraft conceptual design, aircraft performance, structure design, engine design, on-board systems design, RAMS and maintenance cost modules. The RAMS module is used to obtain the failure rates and maintenance effort (in terms of maintenance man hour per flight hour) at subsystem level. The cost module is based on a new maintenance cost model able to estimate the operating cost of the different aircraft variants. The selected new technologies are applied to a regional jet developed within the framework of AGILE research project. For each technology, a different variant of this aircraft is analyzed. Results show that some important saves are reached both in terms of maintenance and fuel cost when new technologies are applied

    Gamification techniques for raising cyber security awareness

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    Due to the prevalence of online services in modern society, such as internet banking and social media, it is important for users to have an understanding of basic security measures in order to keep themselves safe online. However, users often do not know how to make their online interactions secure, which demonstrates an educational need in this area. Gamification has grown in popularity in recent years and has been used to teach people about a range of subjects. This paper presents an exploratory study investigating the use of gamification techniques to educate average users about password security, with the aim of raising overall security awareness. To explore the impact of such techniques, a role-playing quiz application (RPG) was developed for the Android platform to educate users about password security. Results gained from the work highlightedthat users enjoyed learning via the use of the password application, and felt they benefitted from the inclusion of gamification techniques. Future work seeks to expand the prototype into a full solution, covering a range of security awareness issues

    Environmental & flight control system architecture optimization from a family concept design perspective

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    One method an Original Equipment Manufacturer (OEM) can apply to reduce development and manufacturing costs is family concept design: each product family member is designed for a different design point, but a significant amount of components is shared among the family members. In this case, a trade-off exists between member performance and commonality. In the design of complex systems, often many different architectures are possible, and the design space is too large to explore exhaustively. In this work, we present an application of a new architecture optimization method to the design of a family of passenger transport jets, with a focus on the sizing of the Environmental Control System (ECS) and Flight Control System (FCS). The architecture design space is modeled using the Architecture Design Space Graph (ADSG), a novel method for constructing model-based system architecture optimization problems. Decisions are extracted and the multi-objective optimization problem is automatically formulated. Objectives used are commonality, representing acquisition costs, and fuel burn, representing a part of operation costs. These metrics are evaluated using a cross-organizational collaborative multidisciplinary analysis toolchain, and the resulting Multidisciplinary Design Optimization (MDO) problem is solved using a multi-objective evolutionary optimization algorithm. The results show that the trade-off between commonality and fuel burn is only present above a certain commonality level

    Anterior Segment-Optical Coherence Tomography features in Blau syndrome.

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    Blau syndrome (BS) is a rare granulomatous auto-inflammatory disease, characterized by the classic clinical triad of joints, skin and ocular involvements. Ocular manifestation usually consists in a bilateral insidious chronic anterior uveitis with a potential evolution to panuveitis. We describe the case of two siblings, an 8-years old female and a 5-years old male, with a diagnosis of BS, evaluated by Anterior Segment-Optical Coherence Tomography (AS-OCT). In the female patient, slit-lamp examination revealed bilateral anterior granulomatous uveitis and inflammatory sequelae. AS-OCT revealed high intensity reflective layers in the anterior cornea, hyperreflective dots both in the aqueous humor and in the posterior corneal surface. In the male, no signs of inflammation were detected both on slit-lamp examination and AS-OCT scans. AS-OCT is a valuable, non-invasive tool that could improve the diagnosis of ocular involvement, better characterize and follow-up corneal alterations and anterior segment features in pediatric patients with BS

    Thermosonic inspection of carbon fibre reinforced polymer composites using an airborne haptic ultrasonic phased array

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    This paper reports the development of a contactless non-destructive evaluation technique using an air-coupled haptic ultrasonic phased array to induce thermosonic frictional heating in damaged carbon fibre reinforced polymer composites. Haptic ultrasonic systems consist of controllable, narrowband, and high-power piezoelectric transducer arrays that are capable of electronically steering and shaping the ultrasonic beam on the surface of test samples. Localised thermal images of the damaged area were observed using an infrared camera. It was found that the intensity of the thermosonic heating reduced with increased distances between the ultrasonic excitation location and the damage. This approach allowed the ultrasonic focal point to be moved across the sample to identify the areas of damage, without moving either the array or the infrared camera, thus significantly decreasing the time needed for inspection
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