Parametric simulation of LVI test onto CFRP plates

The paper deals with the study of the structural behaviour of laminated composite plates under low velocity impacts. Three test cases, respectively with 6J, 10J and 13J impact energies have been experimentally carried out under ASTM D7136 (American Standard Test Method for Measuring the Damage Resistance of a Fiber –Reinforced Polymer Matrix Composite to a Drop-Weight Impact) requirements. Within this work, virtual simulations of such impact tests have been developed by using the finite element code Abaqus®. The numerical model, based on explicit finite element theory, allows predicting the onset and evolution of both inter-laminar and intra-laminar damages. The former have been considered by using special-purpose elements (cohesive elements); the latter thanks to Hashin criteria. For validation purpose, numerical results have been compared with the experimental ones. After the validation phase, a parametric analysis has been numerically performed; the size of the panel support fixture has been considered as main parameter

Effectiveness of an innovative sensory approach to improve children’s nutritional choices

A case-control study was conducted to investigate the effectiveness of the Edueat® Method, through experiential workshops focused on the use of all 5 senses. In two different primary schools in the same city, questionnaires were administered in two months with a follow-up one year later. Participants: 119 children (age 8.2–9.0) chosen randomly; control group 66 (55.5%). Seven lessons of 2 h each were held in the schools by experts of the Edueat® method and seven extra lessons by the teachers. The main outcome measures were the children’s changes in their approach and attitude towards their eating habits. The answers were grouped with factor analysis and summarized through scores. Repeated-measures analysis of variance was conducted in order to identify the relationships between scores and treatment over time. At the end of treatment, the intervention group showed a significant appreciation towards healthy foods (+4.15 vs. −0.05, p = 0.02) and a greater capacity in identifying foods which are very good for the health (+15.6 vs. +14.4, p = 0.02). In conclusion, the Edueat® method was found to be particularly promising in transmitting knowledge of those foods which are healthy. Greater involvement of teachers and parents is crucial

An EBIS for charge state breeding in the SPES project

The 'charge state breeder', BRIC (breeding ion charge) is in construction at the INFN section of Bari (Italy). It is based on EBIS scheme and it is designed to accept radioactive ion beam (RIB) with charge state +1 in a slow injection mode. This experiment can be considered as a first step towards the design and construction of a charge breeder for the SPES project. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion chamber, of a rf-quadrupole aiming at filtering the unwanted masses and then making a more efficient containment of the wanted ions. In this paper, the breeder design, the simulation results of the electron and ion beam propagation and the construction problems of the device will be reported

A prototype large-angle photon veto detector for the P326 experiment at CERN

The P326 experiment at the CERN SPS has been proposed with the purpose of measuring the branching ratio for the decay K^+ \to \pi^+ \nu \bar{\nu} to within 10%. The photon veto system must provide a rejection factor of 10^8 for \pi^0 decays. We have explored two designs for the large-angle veto detectors, one based on scintillating tiles and the other using scintillating fibers. We have constructed a prototype module based on the fiber solution and evaluated its performance using low-energy electron beams from the Frascati Beam-Test Facility. For comparison, we have also tested a tile prototype constructed for the CKM experiment, as well as lead-glass modules from the OPAL electromagnetic barrel calorimeter. We present results on the linearity, energy resolution, and time resolution obtained with the fiber prototype, and compare the detection efficiency for electrons obtained with all three instruments.Comment: 8 pages, 9 figures, 2 tables. Presented at the 2007 IEEE Nuclear Science Symposium, Honolulu HI, USA, 28 October - 3 November 200

Crashworthiness of a composite bladder fuel tank for a tilt rotor aircraft

The fulfilment of the crash is a demanding requirement for a Tiltrotor. Indeed, such a kind of aircraft, being a hybrid between an airplane and a helicopter, inherits the requirements mainly from helicopters (EASA CS 29) due to its hovering ability. In particular, the fuel storage system must be designed in such a manner that it is crash resistant, under prescribed airworthiness requirements, in order to avoid the fuel leakage during such an event, preventing fire and, thus, increasing the survival chances of the crew and the passengers. The present work deals with the evaluation of crashworthiness of the fuel storage system of a Tiltrotor (bladder tank), and, in particular, it aims at describing the adopted numerical approach and some specific results. Crash resistance requirements are considered from the earliest design stages, and for this reason they are mainly addressed from a numerical point of view and by simulations that treat both single components and small/medium size assemblies. The developed numerical models include all the main parts needed for simulating the structural behavior of the investigated wing section: the tank, the structural components of the wing, the fuel sub-systems (fuel lines, probes, etc.) and the fuel itself. During the crash event there are several parts inside the tanks that can come into contact with the tank structure; therefore, it is necessary to evaluate which of these parts can be a damage source for the tank itself and could generate fuel loss. The SPH approach has been adopted to discretise fuel and to estimate the interaction forces with respect to the tank structure. Experimental data were used to calibrate the fuel tank and foam material models and to define the acceleration time-history to be applied. Thanks to the optimized foam’s configuration, the amount of dissipated impact energy is remarkable, and the evaluation of tanks/fuel system stress distribution allows estimating any undesired failure due to a survivable crash event

Edible cellulose-based conductive composites for triboelectric nanogenerators and supercapacitors

Edible electronics will enable systems that can be safely ingested and degraded in the human body after completing their function, such as sensing physiological parameters or biological markers in the gastrointestinal tract, without risk of retention or need of recollection. The same systems are potentially suitable for directly tagging food, monitoring its quality, and developing edible soft actuators control and sensing abilities. Designing appropriate edible power sources is critical to turn such a vision into real opportunities. We propose electrically conductive edible composites based on ethylcellulose and activated carbon as enabling materials for energy harvesting and storage. Free-standing, phase-separated bi-layered films, insulating at the top and with low electrical resistivity (∼10 Ω cm) at the bottom, were produced with a scalable single-step process. Food additives can tune the mechanical and triboelectrical properties of the proposed edible films. We demonstrated their successful operation as electropositive elements in organic triboelectric nanogenerators (TENGs) and as electrodes in fully edible supercapacitors (SC). The TENGs showed ∼60 V peak voltage (root mean square power density ∼2.5 μW cm−2 at 5 Hz), while the SC achieved an energy density of 3.36 mW h g−1, capacity of ∼ 9 mAh g−1, and stability for more than 1000 charge-discharge cycles. These results show that the combination of ethyl cellulose and activated carbon, and the control over their mixture, allow on-demand edible devices for energy generation and storage, serving future edible and green electronics scenarios

Cherenkov Telescope Array Data Management

Very High Energy gamma-ray astronomy with the Cherenkov Telescope Array (CTA) is evolving towards the model of a public observatory. Handling, processing and archiving the large amount of data generated by the CTA instruments and delivering scientific products are some of the challenges in designing the CTA Data Management. The participation of scientists from within CTA Consortium and from the greater worldwide scientific community necessitates a sophisticated scientific analysis system capable of providing unified and efficient user access to data, software and computing resources. Data Management is designed to respond to three main issues: (i) the treatment and flow of data from remote telescopes; (ii) "big-data" archiving and processing; (iii) and open data access. In this communication the overall technical design of the CTA Data Management, current major developments and prototypes are presented.Comment: 8 pages, 2 figures, In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

Prospects for K+→π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ \to \pi^+ \nu \bar{ \nu }$, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

First Measurement of the Transverse Spin Asymmetries of the Deuteron in Semi-Inclusive Deep Inelastic Scattering

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6-LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.Comment: 6 pages, 2 figure