828 research outputs found
A preliminary study of composite orbiter/ lander missions to satellites of the outer planets
Objectives and payload requirements for composite orbiter/lander missions to satellites of outer planet
Nonlinear phononic crystals based on chains of disks alternating with toroidal structures
We study experimentally the acoustic response of a load-bearing, phononic crystal composed of alternating steel disks, and polytetrafluoroethylene o-rings under precompression. The crystal allows for axial, rocking, and shear-polarized wavemodes when excited by a broad-band signal applied off-axis. Finite element analysis is employed to determine the systemâs wave modes. The nonlinear interaction between disks and o-rings supports a dynamic response that is tunable with variations in static precompression, leading to controllable frequency shifts in a large band gap. A modal analysis reveals that four of the six principal wave modes are susceptible to external precompression while two modes are not
Preliminary feasibility study of soft-lander missions to the Galilean satellites of Jupiter
Feasibility study of soft lander missions to Galilean satellites of Jupite
Suelos volcanicos endurecidos
In the sedimentary basin of Rieti (Central Italy) a Mollic Fragiudalf was studied in order to verify, through the analysis of differential dissolution kinetics of Si and Al, wether the presence of this two elements could be involved in determining the fragic characters of its deep horizons. The reuslts of the main physico-chemical analysis confirmed the fragic features of the deep horizons Bt3x and Ctgx which have been already observed in the field study. Differential dissolution of Si and Al was performed using 0,5 N NaOH at 25°C, and the values of silica and alumina obtained after each of ten consecutive extractions were cumulated to trace the cumulative curves of dissolution. Slope changes of the curves, which indicate changes in dissolution rate, allowed os to recognize three mineralogical phases with different degree of solubility. The total quantity of SiO2 and Al2O3 dissolved in all the extractions and relative to each of these three phases was estimated, by a graphic method, together with SiO2(Al2O3 molar ratio. This one was indicative of the mineralogical composition and behaviour of each horizon. This study showed an accumulation of free silica which could be present in the form of phytoliths or diatoms as well as a fine precipitate of opal-A and silica-gel in the whole soil, mainly in teh Ap and Ctgx horizons. Moreover neogenesis of clay was more evident in Bt3x horizon. The volcanic origin of the parent material, a trachytic ash fall, probably deposited in a lacustrine environment, could have favoured the availability of Si and the authigenic formation of halloysitic clay from the weathering of galss and feldspars. Our study therefore corroborates the findings of previous studies by Chadwick et al. (1987) and Karathanasis (1989) indicating the important role played by silica, probably as bonding agent, in contributing to produce characteristics of a fragipan. (Résumé d'auteur)
Wave Propagation in Auxetic Tetrachiral Honeycombs
This paper describes a numerical and experimental investigation on the flexural wave propagation properties of a novel class of negative Poisson's ratio honeycombs with tetrachiral topology. Tetrachiral honeycombs are structures defined by cylinders connected by four tangent ligaments, leading to a negative Poisson's ratio (auxetic) behavior in the plane due to combined cylinder rotation and bending of the ribs. A Bloch wave approach is applied to the representative unit cell of the honeycomb to calculate the dispersion characteristics and phase constant surfaces varying the geometric parameters of the unit cell. The modal density of the tetrachiral lattice and of a sandwich panel having the tetrachiral as core is extracted from the integration of the phase constant surfaces, and compared with the experimental ones obtained from measurements using scanning laser vibrometers
Design of an Intrinsically Motivating AR Experience for Environmental Awareness
Augmented Reality seems a promising tool to provide engaging and effective educational experiences, thanks to its potentiality in stimulating intrinsic motivation, that could influence the learning process and the attitude of the users towards behaviours. This paper presents the Resized Plastic Augmented Reality learning experience, designed on the basis of Dunleavy's framework to provide a systemic overview of the microplastics issue to allow users to understand its mechanisms, educate them about their role in the system and help them to connect this information to their everyday actions
Poesia in posa
Catalogo della mostra, a cura di C. Gian Ferrari, M. Scolaro, C. Spadoni. Rilettura dell'opera di Felice Casorati con particolare attenzione al contesto di riferimento culturale e alle fonti, all'ambiente torinese che rappresent\uf2 il primo destinatario della sua opera. Analisi approfondite dei rapporti con gli intellettuali piemontesi, con Piero Gobetti, primo esegeta dell'arte di Casorati, e con i coniugi Gualino, importanti figure di committenti/mecenati
Innovative solutions for the wine sector: the role of startups
The economic globalisation has opened new pathways for commerce and triggered a logistical revolution, which in turn has produced enormous technological innovations. In this context, the role of startups is becoming increasingly crucial since they are positioning themselves as innovation enablers among large and small companies. Between these innovations, IoT, Big Data Analytics and Blockchain can be used in various domains, among which the logistics of the whole wine supply chain. Here we will consider some of the issues and needs that arise in this market sector, showing how Wenda, a startup born in Bologna in February 2015 that works to improve sustainability and traceability in Food & Beverage supply chains, has been able to leverage IoT, Big Data Analytics and Blockchain to empower the wine supply chain with solutions that enable wine traceability throughout the distribution and the after-buying-in preservation and commercialisation phases
Augmented Reality to Engage Visitors of Science Museums through Interactive Experiences
In the last years, interactive exhibitions based on digital technologies have become widely common, thanks to their flexibility and effectiveness in engaging visitors and creating memorable experiences. One of the topics in which digital technologies can be particularly effective is the communication of abstract concepts that are difficult for the human mind to imagine. An emblematic example is the astronomy discipline, which requires us to imagine and understand phenomena far away from our everyday life. In this paper, the authors present a research project, MARSS, in which digital technologies are used effectively to enhance the Users' Experience of the Museo Astronomico di Brera located in Milan. Specifically, the MARSS project aims at designing and developing a new digital journey inside the museum to allow different categories of visitors to enjoy the exhibition in an engaging and interactive way. The paper presents the design and development phases of the experience and its evaluation with users. The results of the evaluation indicate that the digital interactive experience is appreciated by users and is successful in translating the content of high scientific value into more engaging and easily understandable elements
Accuracy and Reliability of Dosing Equations to Individualize Theophylline Treatment of Apnea of Prematurity
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90103/1/j.1875-9114.1995.tb04360.x.pd
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