Imaging multi-age construction settlement behaviour by advanced SAR interferometry

This paper focuses on the application of Advanced Satellite Synthetic Aperture Radar Interferometry (A-DInSAR) to subsidence-related issues, with particular reference to ground settlements due to external loads. Beyond the stratigraphic setting and the geotechnical properties of the subsoil, other relevant boundary conditions strongly influence the reliability of remotely sensed data for quantitative analyses and risk mitigation purposes. Because most of the Persistent Scatterer Interferometry (PSI) measurement points (Persistent Scatterers, PSs) lie on structures and infrastructures, the foundation type and the age of a construction are key factors for a proper interpretation of the time series of ground displacements. To exemplify a methodological approach to evaluate these issues, this paper refers to an analysis carried out in the coastal/deltaic plain west of Rome (Rome and Fiumicino municipalities) affected by subsidence and related damages to structures. This region is characterized by a complex geological setting (alternation of recent deposits with low and high compressibilities) and has been subjected to different urbanisation phases starting in the late 1800s, with a strong acceleration in the last few decades. The results of A-DInSAR analyses conducted from 1992 to 2015 have been interpreted in light of high-resolution geological/geotechnical models, the age of the construction, and the types of foundations of the buildings on which the PSs are located. Collection, interpretation, and processing of geo-thematic data were fundamental to obtain high-resolution models; change detection analyses of the land cover allowed us to classify structures/infrastructures in terms of the construction period. Additional information was collected to define the types of foundations, i.e., shallow versus deep foundations. As a result, we found that only by filtering and partitioning the A-DInSAR datasets on the basis of the above-mentioned boundary conditions can the related time series be considered a proxy of the consolidation process governing the subsidence related to external loads as confirmed by a comparison with results from a physically based back analysis based on Terzaghi's theory. Therefore, if properly managed, the A-DInSAR data represents a powerful tool for capturing the evolutionary stage of the process for a single building and has potential for forecasting the behaviour of the terrain-foundation-structure combination

Historic evolution of the optical design of the Multi Conjugate Adaptive Optics Relay for the Extremely Large Telescope

The optical design of the Multi Conjugate Adaptive Optics Relay for the Extremely Large Telescope experienced many modifications since Phase A conclusion in late 2009. These modifications were due to the evolution of the telescope design, the more and more accurate results of the performance simulations and the variations of the opto-mechanical interfaces with both the telescope and the client instruments. Besides, in light of the optics manufacturing assessment feed-backs, the optical design underwent to a global simplification respect to the former versions. Integration, alignment, accessibility and maintenance issues took also a crucial role in the design tuning during the last phases of its evolution. This paper intends to describe the most important steps in the evolution of the optical design, whose rationale has always been to have a feasible and robust instrument, fulfilling all the requirements and interfaces. Among the wide exploration of possible solutions, all the presented designs are compliant with the high-level scientific requirements, concerning the maximum residual wavefront error and the geometrical distortion at the exit ports. The outcome of this decennial work is the design chosen as baseline at the kick-off of the Phase B in 2016 and subsequently slightly modified, after requests and inputs from alignment and maintenance side

MAORY: wavefront sensor prototype and instrument optical design

MAORY will be the multi-conjugate adaptive optics module for the ELT first light. Its main goal is to feed the high-resolution NIR imager and spectrograph MICADO. The present Thesis address the MAORY system at the level of optical design and analysis. MAORY is a complex science projects whose stakeholder is the scientific community. Its requirements are driven by the science cases which request high resolution and astrometric accuracy. In an ideal world without atmospheric turbulence, MAORY optics must deliver diffraction-limited images with very low optical distortions. The tolerance process is one of the most important step in the instrument design since it is intended to ensure that MAORY requested performances are satisfied when the final assembled instrument is operative. The baseline is to operate wavefront sensing using six sodium Laser Guide Stars and three Natural Guide Stars to solve intrinsic limitations of artificial sources and to mitigate the impact of the sodium layer structure and variability. The implementation of a laboratory Prototype for Laser Guide Star wavefront sensor at the beginning of the phase study of MAORY has been indispensable to consolidate the choice of the baseline of wavefront sensing technique. The first part of this Thesis describes the results obtained with the Prototype for Laser Guide Star wavefront sensor under different working conditions. The second part describes the logic behind the tolerance analysis at the level of MAORY optical design starting from definition of quantitative figures of merit for requirements and ending with estimation of MAORY performances perturbed by opto-mechanical tolerances. The sensitivity analysis on opto-mechanical tolerance of MAORY is also a crucial step to plan the alignment concept that concludes the arguments addressed by this Thesis

Geophysical surveys integrated with rainfall data analysis for the study of soil piping phenomena occurred in a densely urbanized area in eastern Sicily

AbstractThe occurrence of strong and abrupt rainfall, together with a wrong land use planning and an uncontrolled urban development, can constitute a risk for infrastructure and population. The water flow in the subsoil, under certain conditions, may cause underground cavities formation. This phenomena known as soil piping can evolve and generate the surface collapse. It is clear that such phenomena in densely urbanized areas represent an unpredictable and consistent risk factor, which can interfere with social activities. In this study a multidisciplinary approach aimed to obtain useful information for the mitigation of the risks associated with the occurrence of soil piping phenomena in urban areas has been developed. This approach is aimed at defining the causes of sudden soil subsidence events, as well as the definition of the extension and possible evolution of these instability areas. The information obtained from rainfall data analysis, together with a study of the morphological, geological and hydrogeological characteristics, have allowed us to evaluate the causes that have led to the formation of soil pipes. Furthermore, performance of 3D electrical resistivity surveys in the area affected by the instability have allowed us to estimate their extension in the subsoil and identifying the presence of further areas susceptible to instability

The numerical simulation tool for the MAORY multiconjugate adaptive optics system

The Multiconjugate Adaptive Optics RelaY (MAORY) is and Adaptive Optics module to be mounted on the ESO European-Extremely Large Telescope (E-ELT). It is a hybrid Natural and Laser Guide System that will perform the correction of the atmospheric turbulence volume above the telescope feeding the Multi-AO Imaging Camera for Deep Observations Near Infrared spectro-imager (MICADO). We developed an end-to-end Monte- Carlo adaptive optics simulation tool to investigate the performance of a the MAORY and the calibration, acquisition, operation strategies. MAORY will implement Multiconjugate Adaptive Optics combining Laser Guide Stars (LGS) and Natural Guide Stars (NGS) measurements. The simulation tool implements the various aspect of the MAORY in an end to end fashion. The code has been developed using IDL and uses libraries in C++ and CUDA for efficiency improvements. Here we recall the code architecture, we describe the modeled instrument components and the control strategies implemented in the code.Comment: 6 pages, 1 figure, Proceeding 9909 310 of the conference SPIE Astronomical Telescopes + Instrumentation 2016, 26 June 1 July 2016 Edinburgh, Scotland, U

The cost-effectiveness of naloxone programs for the treatment of heroin overdose in the ‘street’: a 2-years data collection by the Street Unit of the Villa Maraini Foundation

The mortality rate of opioid users is about 5 to 10 times greater than that of the general population, and the overdose represents the most common cause of death. When timely treated with the opioid antagonist naloxone, the opioid overdose is rarely lethal. Unfortunately, many opioid overdoses occur in isolated, hidden, hard to reach location. To circumvent this problem, Villa Maraini Foundation in Rome has created a rescue team, the Street Unit, to provide basic life support and administer naloxone for the treatment of opioid overdose in urban environments. The aim of this paper is to review the cost-effectiveness of our Street Unit. We evaluated the cost of 90 overdose interventions provided by the Street Unit to that provided by the Accident & Emergency departments of the Italian National Health System. The Street Unit not only successfully treated all overdoses but also provided a dramatic reduction in costs, ranging from €123,367.05 (best-case scenario) to €203,377.05 (worst-case scenario). This finding suggests that the treatment of opioid overdose in the street context represents a safe and cost-effective strategy to reduce opioid overdose related mortality

Assessment of Recycled PLA-Based Filament for 3D Printing

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