Three-dimensional acquisition of large and detailed cultural heritage objects

Cultural heritage digitization is becoming more common every day, but the applications discussed in the literature address mainly the digitization of objects at a resolution proportional to the object size, using low resolution for large artifacts such as buildings or large statues, and high resolution for small detailed objects. The case studied in this paper concerns a huge physical model of imperial Rome (16 × 17.5 m) whose extremely small details forced the use of high resolution and low noise scanning, in contrast with the long range needed. This paper gives an account of the procedures and the technologies used for solving this “contradiction”.     

Analysis of expression in simple musical gestures to enhance audio in interfaces

Expression could play a key role in the audio rendering of virtual reality applications. Its understanding is an ambitious issue in the scientific environment, and several studies have investigated the analysis techniques to detect expression in music performances. The knowledge coming from these analyses is widely applicable: embedding expression on audio interfaces can drive to attractive solutions to emphasize interfaces in mixed-reality environments. Synthesized expressive sounds can be combined with real stimuli to experience augmented reality, and they can be used in multi-sensory stimulations to provide the sensation of first-person experience in virtual expressive environments. In this work we focus on the expression of violin and flute performances, with reference to sensorial and affective domains. By means of selected audio features, we draw a set of parameters describing performers’ strategies which are suitable both for tuning expressive synthesis instruments and enhancing audio in human–computer interfaces.     

Raman Microprobe Evaluation of Bridging Stresses in Highly Anisotropic Silicon Nitride

The microscopic bridging stress distribution developed behind the crack tip of a highly anisotropic silicon nitride has been measured along the crack profile using Raman microprobe spectroscopy with a micrometer spatial resolution. The near-tip rising R -curve behavior and the crack-opening displacement (COD) profile of the material were also determined and discussed in comparison with the Raman microstress data. A comparison with the fracture behavior of a previously investigated silicon nitride material with a three-dimensional random microstructure is also proposed. According to this set of micro/macroscopic fracture characterizations, a self-consistent view of toughening behavior in silicon nitride ceramics is obtained, and the role on toughness of anisotropically oriented acicular grains clarified. In agreement with previous studies, it is confirmed that crack-face bridging is the most effective mechanism for toughening silicon nitride ceramics.     

Photonic slot routing: a cost effective approach to designingall-optical access and metro networks

In the backbone network, the high level of traffic aggregation achieved by numerous users is efficiently served by means of optical circuit switched solutions-the so-called wavelength routing approach. In the access and metro networks, on the contrary, the reduced level of traffic aggregation makes wavelength routing solutions inadequate. The finer and more dynamic bandwidth allocation provided by packet-interleaved optical time-division multiplexing is thus advocated in these network areas. This article presents a survey of an OTDM approach, known as photonic slot routing, or PSR. It is illustrated how this approach may provide a cost-effective solution to deploying all-optical access and metro networks with today's technology     

Q‐factor evaluation,design and accurate EM performance of multilayer dielectric filters

In this contribution we present the design of an optical dielectric multilayered filter by using a transmission‐line prototype. Each resonator of the prototype is realized by means of a stack of dielectric layers by equating the Q‐factor of the stack with that of the corresponding resonator of the prototype. We then compare the analytical results with numerical ones obtained by the finite element method (FEM). We extend the theory to a structure formed by periodic multilayer resonators. Copyright © 2006 John Wiley & Sons, Ltd.     

Heat treatment effects on the corrosion resistance of some HVOF-sprayed metal alloy coatings

The present study evaluates the effects of a 600 °C, 1 h heat treatment on the corrosion resistance of three High Velocity Oxygen Fuel (HVOF) flame-sprayed alloy coatings: a Co-28Mo-17Cr-3Si (similar to Tribaloy-800) coating, a Ni-20Cr-10W-9Mo-4Cu-1C-1B-1Fe (Diamalloy-4006) coating and a Ni-32Mo-16Cr-3Si-2Co (similar to Tribaloy-700) coating. Electrochemical polarization tests and free corrosion tests were performed in 0.1 M HCl aqueous solution. The corrodkote test (ASTM B380-97R02) was also performed, to evaluate the coatings qualitatively. The heat treatment improves the corrosion resistance of the Co-28Mo-17Cr-3Si coating and of the Ni-20Cr-10W-9Mo-4Cu-1C-1B-1Fe coating by enhancing their passivation ability. The precipitation of sub-micron sized secondary phases after the treatment may produce galvanic microcells at intralamellar scale, but the beneficial contribution provided by the healing of the very small but dangerous interlamellar defects (normally present in thermal spray coatings but not detectable using ordinary scanning electron microscopy) prevails. The effect on Ni-32Mo-16Cr-3Si-2Co coatings is more ambiguous: its sensitivity to crevice corrosion is worsened by the heat treatment.     

Selective catalytic reduction (SCR) of NO by NH3 over TiO2-supported V2O5–WO3 and V2O5–MoO3 catalysts

A comparison between commercial and model WO₃–V₂O₅/TiO₂ and MoO₃–V₂O₅/TiO₂ SCR catalysts is considered in this study. The data indicate that WO₃ and MoO₃ behave as “structural” and “chemical” promoters for the catalysts. MoO₃-based catalysts are more active but less selective than WO₃–V₂O₅/TiO₂ catalysts in the SCR reaction, although in the presence of water the catalytic performances of the investigated samples are comparable. This revised version was published online in August 2006 with corrections to the Cover Date.     

New Mixed Esters with a Complex Alkyl‐Aryl Structure Considered as Tribological Fluids

This paper presents the results of a study carried out to produce synthetic ester oils of mixed structure and based on phthalic anhydride with beneficial tribological properties. Three series of unsymmetric diesters were synthesised using aliphatic alcohols such as n‐propanol, n‐butanol, n‐hexanol, 2‐ethylhexanol, isodecanol, and isotridecanol, along with special alcohols of a complex alkyl‐aryl structure, namely 2‐phenoxyethanol, 2‐((o‐sec‐butyl)phenoxylethanol, and 2‐ftp‐nonyl)phenoxylethanol. Also synthesised were symmetric esters based on these special aliphatic‐aromatic alcohols. The variation in the principal properties as a function of both the length of the aliphatic chain introduced by the aliphatic alcohol and the length and position of the aliphatic pendant chain on the aromatic nucleus of the complex alkyl‐aryl alcohol was assessed. Based on this, it has been possible to obtain fluid products with variable properties. The introduction of the aromatic function in the structure of these diesters leads to interesting features, and the wide range of viscosity values demonstrates their versatility.     

Analysis of RGB-D camera technologies for supporting different facial usage scenarios

Multimedia Tools and Applications - Recently a wide variety of applications has been developed integrating 3D functionalities. Advantages given by the possibility of relying on depth information...     

Observational constraints of the past CO2 concentration on the results of carbon cycle models

A paper by Zecca and Chiari has followed the work of Nel and Cooper (both in Energy Policy), dealing with the same issue of evaluating the future atmospheric CO₂ concentration under the constraints imposed by fossil-fuels depletion. The two papers suggest the need of revising the IPCC SRES emission scenarios. In this number, further works by Ward and Nel and by Zecca and Chiari aim at improving the outcomes of the carbon cycle models used for the calculation of the CO₂ concentration starting from the emission values. Here, methodological differences between the two groups are discussed.