Proof of Concept Experience in the SPES Experiment: First Solutions for Potentiometers Replacement in System Maintenance

AbstractSPES (Selective Production of Exotic Species) is a large facility, currently under advanced construction at the INFN-LNL (Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro) for the production of Radioactive Ion Beams (RIBs). Coordinated efforts are being dedicated to the development and upgrading of both the accelerator complex and the up-to-date experimental set-ups. This paper describes a work of upgrading as far as the inspection and maintenance of the system is concerned, and it deals with human-centered design methods to reduce the time spent in the radioactive environment of the facility during ordinary maintenance operations and to simplify them, also considering stress conditions of the operator and the mandatory wearable radiation protection devices (such as tracksuit, gloves, oxygen tank mask) which make simple operations difficult

Technical Drawing Learning Tool-Level 2: An interactive self-learning tool for teaching manufacturing dimensioning

This work presents an interactive self-learning tool named Technical Drawing Learning Tool-Level 2\u2014TDLT-L2\u2014for teaching manufacturing dimensioning to engineering students. The tool was designed for the students enrolled in the first year of the Bachelor in Management and Mechanical Engineering of the Universities of Brescia and Udine. It consists of a simple interactive tool, based on video and drawing animations, aimed at demonstrating the connection between real and simple machining processes and workpiece dimensions on technical drawing. TDLT-L2 is currently available in two versions: as a standalone application for Windows or Android based operating systems and as a set of interactive PDF documents. It was conceived as the first module of a package of tools that will be developed, based on the learning levels proposed in the Technical Drawing Evaluation Grid\u2014TDEG. A preliminary evaluation of TDLT-L2 effectiveness was done involving the Management and Mechanical engineering students of Udine in some dimensioning exercises. The statistically considerations done on the obtained results confirmed the validity of the tool as a self-learning instrument with an average increase of marks of about 8.8%. \ua9 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:519\u2013528, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21728. \ua9 2016 Wiley Periodicals, Inc

Dynamical behaviour of Bronze Age war chariots

The dynamical behaviour of the Bronze Age war chariots was studied, considering the different assembly solutions that were found in evidences and pictures. In particular, the chariots with the axle in rear position, typical of Near-East and Egypt, were compared with the European ones, which generally had the axle in central position under the chariot cockpit. Furthermore, the role of the floor, usually realized in woven leather or other organic fibres, was investigated. Dynamical finite element and multibody simulation software was used for studying the behaviour of the chariots in occasional overloading events, such as bumps or curves. An experimental device was set up for studying the difference of the response of a woven floor with respect to a wooden one. Finally, a finite element frequency response analysis was carried out to investigate the behaviour in full run over a rough ground. The results showed that position of the axle did not significantly influence the response of the chariot to occasional overloads. On the contrary, it had a strong influence on the stability of the passengers: rear axle chariots were much more effective in cutting the vibrations transmitted to the passengers when running at high speed. This effect was amplified by an increased floor flexibility, which was achieved with a woven floor. These findings could explain the diffusion of the rear-axle chariots in the Near-East and Egypt, where the chariotry was the most important part of the armies: indeed, the effectiveness in cutting the vibrations at high speed should be a crucial factor for ensuring the required precision to the transported archers. On the contrary, the likely marginal role of the chariots in the European armies could lead to the diffusion of central axle model, which ensured a lower burden on the draught horses

Silencer Design for the Control of Low Frequency Noise in Ventilation Ducts

The control of noise propagating along ventilation system ducts has always been an important issue in the building and vehicle sectors. This problem is generally tackled by selecting noise-reducing components with a suitable transmission loss, possibly verifying their effectiveness at a later time. The aim of this article is to characterize the nature of the problem and propose a design approach focusing directly on the perceived effect, that is, on the sound pressure level downstream of the outlet. Because the nature of the noise emission depends on various generation mechanisms, different methods can be applied. Usually, it is more difficult to realize good attenuations at low frequencies because of the limits of sound absorbing materials in such frequency range. For this reason, the ability of reactive components to attenuate the noise below the cut-on frequency will be investigated. This goal is reached by applying the transfer matrix approach to a duct system, with the implementation of the transfer matrices of each single element, and then assembling a system capable of acoustically describing the source and the duct structure. The coupling between the duct system with source and receiver impedances allows one to predict the sound pressure level at a given distance from the outlet. The proposed methodology is implemented in a user-friendly calculation tool with possible academic and professional application. Predictive capability, usability, and intuitiveness of the proposed design procedure are validated against experimental results by real potential users, who express positive feedback