Geological 3D modeling for excavation activity in an underground marble quarry in the Apuan Alps (Italy)

The three-dimensional laser scanning technique has recently become common in diverse working environments. Even in geology, where further development is needed, this technique is increasingly useful in tackling various problems such as stability investigations or geological and geotechnical monitoring. Three-dimensional laser scanning supplies detailed and complete geometrical information in short working times, as a result of the acquisition of a large number of data-points that accurately model the detected surfaces. Moreover, it is possible to combine these data with high quality photographic images so as to provide important information for geological applications, as follows. A working approach, that combines terrestrial laser scanning and traditional geological surveys, is presented. A three-dimensional model, that includes information about the geological structure in an underground quarry in the Apuan Alps, is realized. This procedure is adaptable to other geological contexts, and because of its operating speed and accuracy it is invaluable for optimal excavation, in which a proper planning of quarrying activity is vital for safety and commercial reasons. © 2014 Elsevier Ltd.The authors gratefully acknowledge the assistance of the personnel of the Romana Quarry and particularly Geol. Massimo Corniani. This paper was possible because of support from the Tuscany Region Research Project known as “Health and safety in the quarries of ornamental stones – SECURCAVE”

A GPU-based survey for millisecond radio transients using ARTEMIS

Astrophysical radio transients are excellent probes of extreme physical processes originating from compact sources within our Galaxy and beyond. Radio frequency signals emitted from these objects provide a means to study the intervening medium through which they travel. Next generation radio telescopes are designed to explore the vast unexplored parameter space of high time resolution astronomy, but require High Performance Computing (HPC) solutions to process the enormous volumes of data that are produced by these telescopes. We have developed a combined software /hardware solution (code named ARTEMIS) for real-time searches for millisecond radio transients, which uses GPU technology to remove interstellar dispersion and detect millisecond radio bursts from astronomical sources in real-time. Here we present an introduction to ARTEMIS. We give a brief overview of the software pipeline, then focus specifically on the intricacies of performing incoherent de-dispersion. We present results from two brute-force algorithms. The first is a GPU based algorithm, designed to exploit the L1 cache of the NVIDIA Fermi GPU. Our second algorithm is CPU based and exploits the new AVX units in Intel Sandy Bridge CPUs.Comment: 4 pages, 7 figures. To appear in the proceedings of ADASS XXI, ed. P.Ballester and D.Egret, ASP Conf. Se

An RBF Meshless Approach to Evaluate Strain Due to Large Displacements in Flexible Printed Circuit Boards

Thin plates are very often employed in a context of large displacements and rotations, for example, whenever the extreme flexibility of a body can replace the use of complicated kinematic pairs. This is the case of the flexible Printed Circuit Boards (PCBs) used, for example, within last-generation foldable laptops and consumer electronics products. In these applications, the range of motion is generally known in advance, and a simple strategy of stress assessment leaving out nonlinear numerical calculations appears feasible other than desirable. In this paper, Radial Basis Functions (RBFs) are used to represent a generic transformation of a bi-dimensional plate, with all the derivate fields being analytically achieved without the need for a numerical grid for large-displacement applications. Strains due to bending are easily retrieved with this method and satisfactorily compared to analytical and shell-based Finite Element Method (FEM) benchmarks. On the other hand, the computational costs of the juxtaposed methods appear far different; with the machine being equal, the orders of magnitude of the time elapsed in computation are seconds for the RBF-based strategy versus minutes for the FEM approach

Conventional Fast Neutron Flux Measurement in the Radial Piercing Channel D of the TRIGA Mark II Reactor, Pavia

open8openMarco Di Luzio; Giancarlo D’Agostino; Setareh Fatemi; Barbara Smilgys; Andrea Salvini; Massimo Oddone; Saverio Altieri; Michele PrataDI LUZIO, Marco; D'Agostino, Giancarlo; Fatemi, Setareh; Smilgys, Barbara; Salvini, Andrea; Oddone, Massimo; Altieri, Saverio; Prata, Michel

Una procedura per la valutazione dei limiti di utilizzo di O-Ring sottoposti ad intensi fasci di neutroni

Si presenta una procedura per la previsione della durata di utilizzo di O-ring in materiale polimerico impiegati nei bersagli per la produzione di fasci di ioni radioattivi. Si sono dapprima condotte prove di tenuta a vuoto e analisi a elementi finiti di un O-ring di riferimento operante con diversi livelli di interferenza con la cava, identificando la precompressione limite per la tenuta e la corrispondente pressione di contatto con la cava. Si sono poi effettuate prove di trazione e di Compression Set su campioni di O-ring in EPDM, preventivamente sottoposti a diversi livelli di irraggiamento in campi misti di neutroni e gamma, analizzando l’effetto della dose assorbita sul comportamento meccanico del materiale e sulle corrispondenti proprietà resistenziali, e definendo opportune leggi costitutive. Si sono infine simulate le progressive modifiche di comportamento della guarnizione indotte dall’irraggiamento, prevedendone la durata in esercizio in termini di tenuta e di resistenza strutturale

Interactions of Heavy Hadrons using Regge Phenomenology and the Quark Gluon String Model

The search for stable heavy exotic hadrons is a promising way to observe new physics processes at collider experiments. The discovery potential for such particles can be enhanced or suppressed by their interactions with detector material. This paper describes a model for the interactions in matter of stable hadrons containing an exotic quark of charges $\pm {1/3}e$ or $\pm {2/3}e$ using Regge phenomenology and the Quark Gluon String Model. The influence of such interactions on searches at the LHC is also discussed

Stress–Strain Investigation of the Rock Mass Based on Overcoring with CSIRO HI Cell Test and Numerical Modeling: A Case Study from an Italian Underground Marble Quarry

The present research illustrates the application of a methodological approach to studying the stress–strain distribution in a marble quarry of the Apuan Alps mining area (Italy). This study has been carried out in the framework of a project involving the University of Siena and the UOC Ingegneria Mineraria—USL Toscana Nord-Ovest, Tuscany Region. This stress–strain analysis aims foremost to monitor the slope stability conditions to guarantee a safe workplace for the personnel involved in mining activities, and to enable more sustainable long-term planning for excavation and production. The involved survey activities are as follows: (i) terrestrial laser scanning; (ii) engineering–geological data mapping; and (iii) in situ marble stress measuring through four CSIRO-type cell tests executed in different locations and at various depths within the underground excavation walls. The gathered data converged into numerical models of the quarry, both in 2D (DEM) and 3D (FEM), calibrated by in situ stress results through a rigorous back analysis assessment using least squares procedures. The created models represent a valuable tool for the identification and securing of risk areas and for future excavation planning in respect of the site efficiency and safety