149 research outputs found
La presenza naturale ed antropica di metalli e metalloidi nei terreni e nelle acque della successione umbro-marchigiana. Studio ecologico della Bassa Vallesina
No full textThis PhD thesis concerns an ecological study aimed at identifying the natural and anthropogenic presence of the main metals / metalloids in the environment, together with an assessment of the risk related to their presence in environmental receptors. All these aspects, also in relation to the limit values set by the national and community regulations in force, have been contextualised in an ecological study of the Low Esino Valley (Marche, Italy).
The research carried out shows a substantial concordance between the literature data and the natural background values for the soil and groundwater environmental matrixes, determined in an area adjacent to the study area with similar geological peculiarities. Concentrations exceeding the national regulatory limit values, were mainly found in groundwater (species for Fe, Mn, Pb and in the alternative Al, Zn and As) and inorganic salts (Chlorides, Sulphates). These geochemical anomalies are found in correspondence and/or proximity of certain geological formations (clays, evaporitic rocks), in intensely tectonized zones or in areas close to overhangs and in ephemeral aquifers characterized by low oxygenation and high content of organic matter.
The Low Esino Valley, choice both for geological contiguity with the areas used for the study of the natural background, and for the extensive anthropization, has been the subject of a census of anthropic activities of potential contribution of metals through one of the indicators proposed by the European Environmental Agency (EEA).
The processing of ERA (Ecological Risk Assessments) in the investigated area has shown a potential risk of minimal adverse effects in the environment, prevalently for aquatic organisms by As, Total Cr, Hg, Ni, Pb, Cu, Se and V. In a compromised environmental scenario, concomitant presence of metals and anthropogenic compounds (Hydrocarbons, Halogenated Solvents and Nitrates), the conduction of the ERA reveals instead potential adverse effects not only for the aquatic communities, but also for small birds and fish.
The data, acquired through the various survey steps, lay the foundations for an environmental characterization of the study area, to define both the operational priority criteria aimed at environmental rehabilitation, and the precautionary limit values for sensitive environmental targets, this last defined at a site-specific scale
Surface-micromachined Silicon Carbide Pirani Gauges for Harsh Environments
No full textThe application of pressure sensors in harsh environments is typically hindered by the stability of the material over long periods of time. This work focuses on the design and fabrication of surface micromachined Pirani gauges which are designed to be compatible with state-of-the-art Silicon Carbide CMOS technology. Such an integrated platform would boost harsh environment compatibility while reducing the required packaging complexity. An analytical model was derived describing the design variables of the Pirani gauges followed by Finite Element Analysis. The Pirani gauges were fabricated in a CMOS compatible cleanroom with a process employing only three masks, thus suitable for mass production. The SiC-based Pirani gauge is far more competitive than the traditional Si-based Pirani gauge in terms of endurance in high-temperature environments. From 25°C to 650°C, the gauge shows a reproducible response to pressure changes and has a maximum sensitivity of /Pa at room temperature, and of /Pa at 650°C. Additionally, some of the gauges were demonstrated to operate at temperatures up to 750°C.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and MaterialsQN/Zandbergen La
A miniaturized low power Pirani pressure sensor based on suspended graphene
No full textWorlds first graphene-based Pirani pressure sensor is presented. Due to the decreased area and low thickness, the graphene-based Pirani pressure sensor allows for low power applications down to 0.9 mW. Using an innovative, transfer-free process, suspended graphene beams are realized. This allows for up to 100x miniaturization of the pressure sensor area, while enabling wafer-scale fabrication. The response of the miniaturized pressure sensor is similar to that of the much larger state-of-the-art Si-based Pirani pressure sensors, demonstrating the potential of graphene-based Pirani sensors.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and MaterialsQN/Steeneken LabQN/van der Zant LabDynamics of Micro and Nano System
Per una rilettura dei patti tra il comune di Fermo e i signori del contado del 1229
No full textThe starting point of this artitcle is represented by a paper that Giacinto Pagnani
published in 1972 in Studi Maceratesi (Patti fra il comune di Fermo e i nobili del
contado nel 1229). Along the lines of the most recent historiographical approaches,
the author offers a new interpretation of the document studied by Pagnani more than
40 years ago. A new edition of the document is also provide
Leveraging BIM and Mixed Reality to Actualize Lean Construction
No full textLean construction is made of principles, measures and methods that aim at maximizing process efficiency. Several tools have been developed to minimize waste, maximize customer value, improve the conduction of processes, and pursue other sub-objectives in construction. This effort is becoming more and more important due to the rising construction project size and variety, displacement of resources in diverse geographic locations, high-performance pressure. This paper reports the development and on-site tests in a real-life demonstrator of two management tools, which apply some principles of lean construction management at the design and delivery phases. The first one takes advantage of the integration between BIM and mixed reality, having the final aim of improving collaboration and communication among the actors involved. The second one exploits BIM modelling and search algorithms within a process-based management platform, in order to facilitate short-cycle planning and distributed decision-making in the production process. Both tools have been tested in the case of a building renovation project. The results show that they can improve communication efficiency, reduce rework, speed up work monitoring, control and supervising in construction management, and that they can address several of Liker’s lean principles, as classified by the 4P model
Corrigendum to “Fatal inhalation of nitrogen inside a closed environment: toxicological issues about the cause of death” [Forensic Sci. Int. 302C (2019) 109871] (Forensic Science International (2019) 302, (S0379073819302865), (10.1016/j.forsciint.2019.06.029))
No full textThe authors regret that Dr. Alberto Amadasi and Dr. Alessio Battistini have been missed from the author list. The author list should have been as: Alfredo Fabrizio Lo Faroa, Alessio Battistinic, Filippo Pirania, Alberto Amadasic, Antonino Paratoreb, Adriano Tagliabraccia, Francesco Paolo Busardòa aSection of Legal Medicine, Università Politecnica delle Marche, Ancona, Italy biCTLab s.r.l. Spin-off of University of Catania, Catania, Italy cSezione di Medicina Legale e delle Assicurazioni – Dipartimento di Scienze Biomediche per la Salute – Università degli Studi di Milano The authors would like to apologise for any inconvenience caused
Multi-layer graphene Pirani pressure sensors
No full textThe operating principle of Pirani pressure sensors is based on the pressure dependence of a suspended strip's electrical conductivity, caused by the thermal conductance of the surrounding gas which changes the Joule heating of the strip. To realize such sensors, not only materials with high temperature dependent electrical conductivity are required, but also minimization of the suspended strip dimensions is essential to maximize the responsivity and minimize the power consumption. Due to this, nanomaterials are especially attractive for this application. Here, we demonstrate the use of a multi-layer suspended graphene strip as a Pirani pressure sensor and compare its behavior with existing models. A clear pressure dependence of the strip's electrical resistance is observed, with a maximum relative change of 2.75% between 1 and 1000 mbar and a power consumption of 8.5 mW. The use of graphene enables miniaturization of the device footprint by 100 times compared to state-of-the-art. Moreover, miniaturization allows for lower power consumption and/or higher responsivity and the sensor's nanogap enables operation near atmospheric pressure that can be used in applications such as barometers for altitude measurement. Furthermore, we demonstrate that the sensor response depends on the type of gas molecules, which opens up the way to selective gas sensing applications. Finally, the graphene synthesis technology is compatible with wafer-scale fabrication, potentially enabling future chip-level integration with readout electronics.Electronic Components, Technology and MaterialsPhotovoltaic Materials and DevicesQN/van der Zant LabDynamics of Micro and Nano SystemsQN/Steeneken La
Consumer perception of different species and presentation forms of fish: An empirical analysis in Italy
No full textFish consumption analysis involves public and commercial interests. Many studies have focused on this issue over the last few decades. Researchers rarely consider the heterogeneity of these products, while we believe there are at least five reasons why it should always be taken into account: (i) health factors; (ii) environmental drawbacks regarding the consumption of particular species; (iii) the importance of species and how the fish are presented to consumers; (iv) the perceived differences between species are of prime importance for marketing strategies; and finally (v) being able to identify different species helps prevent fraud. Through perceptual mapping we studied the perceived differences between European anchovies (Engraulis encrasicholus), European sardines (Sardina pilchardus) and mackerel (Sgomber spp.), wild-caught cod and sole, and farmed sea bream and sea bass. We checked for the influence of gender, age, education and residence in how consumers perceive seafood. We found that the gender, age and education of consumers do not usually affect their perception of blue fish as being cheap, flavorsome and traditional, cod and sole as nutritional, and farmed sea bream and bass as natural. A slight difference was found in central/southern Italian residents, who perceive farmed sea bream and bass as cheap and flavorful. The results validate the idea that consumers recognize the different attributes of each species or type of fish for sale, but some issues remain unresolved and further studies are recommended
Single-Walled Carbon Nanotube Pirani Gauges Prepared by DEP Assembly
No full textThis paper reports the design, fabrication, and characteristics of the single-walled carbon nanotubes (SWNTs) Pirani gauge fabricated by dielectrophoretic assembly first which requires simple equipments and process, costs little, and operates at room temperature without limitation on the materials of electrode and substrate. Its theory and design were described in detail. The characteristics were measured and analyzed systematically such as current-voltage, resistance-temperature, thermal response, resistance-pressure, and power consumption properties. The results show that this SWNTs Pirani gauge has rapid thermal response of milliseconds and can operate at very low power consumption down to 15 nW. It reveals a wide linear dynamic range from 0.8 to 80 000 Pa and high sensitivity about 8 k Omega/Pa on average.Engineering, Electrical & ElectronicNanoscience & NanotechnologyMaterials Science, MultidisciplinaryPhysics, AppliedSCI(E)EI1ARTICLE3323-3291
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