3,410 research outputs found

    Modello dinamico di un veicolo cingolato

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    2012 - 2013L'obiettivo della tesi e la modellazione dinamica di un veicolo cingolato o -road, e lo sviluppo di una legge di controllo che lo renda autonomo. L'obiettivo del controllo, e rendere il veicolo capace di operare in completa sicurezza ed autonomia su terreni con angoli di pendenza massima pari a 20 . Il sistema, denominato UTV (Unmanned Tracked Vehicle), e pensato per il trasporto di merci su terreni sconnessi con forte pendenze e di di cile accesso. La propulsione e data da un motore a combustione interna a quattro tempi e il veicolo ha una geometria pari a 180 mm di larghezza, una carreggiata di 670 mm e una lunghezza di impronta di 580mm. La modellazione e stata sviluppata in ambiente Solidworks che integrato con il software SimMechanics della Mathworks ha permesso la realizzazione di un modello multi-body. Tale modello e stato impiegato per la progettazione di leggi di controllo in open loop e closed loop, avendo de nito un opportuno set di attuatori e di sensori. Le leggi di controllo, de nite in simulazione sono state implementate sulla macchina e, mediante una procedura di identi cazione N4SID si e ottenuto il relativo modello dinamico identi cato. Su tale ultimo modello si e sviluppato una legge di controllo ottima in retroazione al ne di rendere robusto il controllo. [a cura dell'autore]XII n.s

    Using flood water in Managed Aquifer Recharge schemes as a solution for groundwater management in the Cornia valley (Italy)

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    The lower Cornia valley aquifer system (Tuscany, Italy) provides the only source of water for drinking, irrigation, industrial purposes and it also contributes to the water needs of the nearby Elba island. Since 60 years, intensive exploitation of groundwater resulted in consistent head lowering and water balance deficit, causing subsidence, reduction of groundwater dependent ecosystems, and salinization of freshwater resources. Rebalancing the water budget of the hydrologic system is the main objective of the LIFE REWAT project (sustainable WATer management in the lower Cornia valley through demand REduction, aquifer Recharge and river REstoration; http://www.liferewat.eu). Here, five demonstration measures (river restoration; Managed Aquifer Recharge; reuse of treated wastewater for irrigation; high irrigation efficiency scheme; leakage management in water distribution systems) are set in place for promoting water resource management, along with capacity building and participatory actions. A pilot Managed Aquifer Recharge (MAR) infiltration basin for using flood-water was designed and set in operation in Suvereto, testing the new-issued Italian regulation on artificial recharge of aquifers (DM 100/2016). The infiltration basin is located at a pre-existing topographical low near the Cornia River. The river, having intermittent flow, provides the recharge water during high flow periods, including floods, and when discharge is above the minimum ecological flow. The infiltration basin is set in a groundwater recharge area where the aquifer is constituted by gravel and sands. A preliminary project and an executive one were prepared and discussed with the relevant authorities, following one-year long monthly monitoring of surface- and ground-water. The project was supported by a groundwater flow modelling-based approach using the FREEWAT platform (www.freewat.eu). The facility consists of the following elements: i) intake work on the River Cornia; ii) the inlet structure control system, managed by quality (mass spectrometer defining surface water spectral signature) and level probes, and allowing pumping into the facility at predefined head and chemical quality thresholds; iii) a sedimentation basin; iv) the infiltration area (less than 1 ha large); v) the operational monitoring system, based on a network of piezometers where both continuous data (head, T, EC, DO) are gathered and discrete measurements/sampling performed. The cost of construction of the plant is about 300000 C well below the cost of a surface water reservoir for a similar storage. Depending on the climatic conditions, the estimated volume of diverted surface water may vary between 300000 m3/year and 2 Mm3/year. Being the facility a pilot one, diverted water discharge ranges between 20 to 50 l/s. Minimal site development and modification was required, resulting in a no-impact water-work, while providing ecosystem benefits by reconnecting and inundating former abandoned riverbeds. The effectiveness of such pilot may demonstrate the potential for Flood-MAR schemes to increase water availability in scarcity prone areas

    Identification and Somatic Characterization of the Germline PTEN Promoter Variant rs34149102 in a Family with Gastrointestinal and Breast Tumors

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    Genetic variants located in non-coding regions can affect processes that regulate protein expression, functionally contributing to human disease. Germline heterozygous mutations in the non-coding region of the PTEN gene have been previously identified in patients with PTEN hamartoma tumor syndrome (PHTS) diagnosed with breast, thyroid, and/or endometrial cancer. In this study, we report a PTEN promoter variant (rs34149102 A allele) that was identified by direct sequencing in an Italian family with a history of gastroesophageal junction (GEJ) adenocarcinoma and breast cancer. In order to investigate the putative functional role of the rs34149102 A allele variant, we evaluated the status of PTEN alterations at the somatic level. We found that PTEN protein expression was absent in the GEJ adenocarcinoma tissue of the index case. Moreover, we detected the occurrence of copy number loss involving the PTEN rs34149102 major C allele in tumor tissue, revealing that the second allele was somatically inactivated. This variant is located within an active regulatory region of the PTEN core promoter, and in silico analysis suggests that it may affect the binding of the nuclear transcription factor MAZ and hence PTEN expression. Overall, these results reveal the functional role of the PTEN promoter rs34149102 A allele variant in the modulation of PTEN protein expression and highlight its contribution to hereditary cancer risk

    An Anomalous Extra Z Prime from Intersecting Branes with Drell-Yan and Direct Photons at the LHC

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    We quantify the impact of gauge anomalies at the Large Hadron Collider by studying the invariant mass distributions in Drell-Yan and in double prompt photon, using an extension of the Standard Model characterized by an additional anomalous U(1) derived from intersecting branes. The approach is rather general and applies to any anomalous abelian gauge current. Anomalies are cancelled using either the Wess-Zumino mechanism with suitable Peccei-Quinn-like interactions and a Stueckelberg axion, or by the Green-Schwarz mechanism. We compare predictions for the corresponding extra Z-prime to anomaly-free realizations such as those involving U(1)_{B-L}. We identify the leading anomalous corrections to both channels, which contribute at higher orders, and compare them against the next-to-next-to-leading order (NNLO) QCD background. Anomalous effects in these inclusive observables are found to be very small, far below the percent level and below the size of the typical QCD corrections quantified by NNLO K-factors.Comment: 46 pages, 36 figures, comments and citations adde

    AC/DC: The FERMI FEL Split and Delay Optical Device for Ultrafast X-ray Science

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    Free-electron lasers (FELs) are the most advanced class of light-sources, by virtue of their unique capability to lase high-brightness pulses characterized by wavelengths spanning the extreme-ultraviolet, the soft and hard X-ray spectral domains, as well as by temporal lengths lying in the femtosecond (fs) timescale. The next step to push the current standards in ultrafast X-ray science is strongly linked to the possibility of engineering and exploiting time-resolved experiments exclusively for FELs pulses, ideally having different colors tunable at specific electronic resonance of the chemical elements. At the seeded FERMI FEL (Trieste, Italy) this goal is committed to the optical device known as AC/DC, which stands for the auto correlator/delay creator. AC/DC is designed to double the incoming FEL pulse splitting the photon beam by inserting a grazing incidence flat mirror, thus preserving the spectral and temporal properties, and further delaying one of these two pulses in time. It can independently tune the FEL pulses fluence on the two optical paths by means of solid-state filters, too. Here, we present a detailed description about this optical device. Strong emphasis is dedicated to the AC/DC opto-mechanical design and to the laser-based feedback systems implemented to compensate for any mismatch affecting the FEL optical trajectory, ascribable to both mechanical imperfections and paraxial errors rising during a temporal delay scan

    A comprehensive suite of earthquake catalogues for the 2016-2017 Central Italy seismic sequence

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    The protracted nature of the 2016-2017 central Italy seismic sequence, with multiple damaging earthquakes spaced over months, presented serious challenges for the duty seismologists and emergency managers as they assimilated the growing sequence to advise the local population. Uncertainty concerning where and when it was safe to occupy vulnerable structures highlighted the need for timely delivery of scientifically based understanding of the evolving hazard and risk. Seismic hazard assessment during complex sequences depends critically on up-to-date earthquake catalogues—i.e., data on locations, magnitudes, and activity of earthquakes—to characterize the ongoing seismicity and fuel earthquake forecasting models. Here we document six earthquake catalogues of this sequence that were developed using a variety of methods. The catalogues possess different levels of resolution and completeness resulting from progressive enhancements in the data availability, detection sensitivity, and hypocentral location accuracy. The catalogues range from real-time to advanced machine-learning procedures and highlight both the promises as well as the challenges of implementing advanced workflows in an operational environment
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