Marco Gargano

Thermographic inspection of cracks in the mixed materials statue: Ratto delle Sabine

This work describes a simple use of active Infrared Thermography developed to detect the level of weathering of a statue with respect to cracks observed on the surface. The statue “Ratto delle Sabine” of Giambologna is exposed in the Galleria of the Accademia in Florence-Italy and was the object onto which the methodology of analysis was used. Radiographic analyses indicated that the statue was originally made out of composite materials (mainly wood and tissue at the inner part and raw clay at the outer part). This artefact is a model which was originally not conceived to last for a long time and nowadays shows severe cracks. Thermal investigations have been done in laboratory and in field to evaluate the level of weathering of the statue, in particular related to the previously mentioned cracks. The main purpose of this study was to find a way to detect and/or demonstrate eventual interconnections between the different cracks and to evaluate the state of weathering of the statue. The methodology is based on insufflating hot air locally into the cracks of the statue during a short time, monitoring at the same time the surface temperature evolution near to the place of inflow and observing if the hot air emerges at the opposite side.To assess the eventual danger of this methodology of blowing in hot air locally, preliminary tests were made in laboratory using samples composed out of different combinations of materials (raw clay, wood, tissue, etc.) similar to the ones composing the statue. Such tests have shown that a heating time of a few minutes was sufficient to highlight the leaking of warm air from the inflow opening to the back side and this without an excessive temperature increase of the surface near the infiltration point. This was done respecting the conservation restrictions and rules for the these materials. Results in lab and field demonstrated the potential efficiency of the method to monitor the conservation state of this fragile artefact. In this specific application the method allowed to identify four critical points in the “Ratto delle Sabine” model.

A multidisciplinary materials characterization of a Joannes Marcus viol (16 th century)

BackgroundSeveral musical instruments in the past centuries were decorated with engravings, inlays, or paintings. This paper focuses on an integrated approach to detect and characterize the kind of dyes when used for the decorations. The multi analytical campaign was performed on a viol made by Joannes Marcus in the second half of the 16th century. The instrument has been shattered during World War II, and the fragments are now held in Conservatorio Giuseppe Verdi in Milan; they still conserve the original black and white purflings and the painted decorations. The study is of critical importance since Joannes Marcus worked in the sixteenth century and, in this very period, some executive features were introduced in musical instrument making, which are now veritable standards for this kind of instruments.ResultsAt first, UV fluorescence examination and reflectographic analysis have been performed on the different fragments in order to characterize, respectively, the distribution of varnishes and glues on the surface and to select the areas treated with metal-gall inks that result transparent by long wave IR reflectographic technique. The materials were therefore characterized with X-Ray Fluorescence (EDXRF), Scanning Electron Microscopy with Energy dispersive X-Ray spectroscopy (SEM-EDX) microanalyses and Micro-Infrared Spectroscopy (μFT-IR) techniques. In particular, the metallic elements present in the dyes where revealed through XRF and SEM-EDX, while μFT-IR gave details about organic binders. Elemental compositions obtained for the black decorations allowed to distinguish original parts of the fragments from those restored or remade.ConclusionsThe characterization of materials performed by our multi analytical approach, allowed us to get a deep knowledge of the technology of this ancient viol maker.In particular, the varnishes are probably composed by a diterpenic and/or triterpenic resin. In the same way, in a few traces of glue the presence of proteinaceous substances have been individuated. As for the brush-decorated area, they present a preparation layer rich in feldspars on which a black layer of carbon black particles is applied. On the other hand the purfling areas are colored by an iron-gall dye. In particular the usage of a different ink allowed to identify restored areas.

Study of Fricke-gel dosimeter calibration for attaining precise measurements of the absorbed dose

A calibration method has been studied for attaining, with good precision, absolute measurements of the spatial distribution of the absorbed dose by means of the Fricke gelatin xylenol orange dosimetric system. With this aim, the dose response to subsequent irradiations was analyzed. In fact, the studied modality is based on a pre-irradiation of each single dosimeter in a uniform field with a known dose, in order to extrapolate a calibration image for a subsequent non-uniform irradiation with an unknown dose to be measured.

Ionizing radiation detection by Yb-doped silica optical fibers

Rare earths-doped silica optical fibers have shown promising results for ionizing radiation monitoring, thanks to their radio-luminescence (RL) properties. However, the use of these systems for accurate and precise dosimetric measurements in radiation fields above the Cerenkov energy threshold, like those employed in radiation therapy, is still challenging, since a spurious luminescence, namely the “stem effect,” is also generated in the passive fiber portion exposed to radiation. The spurious signal mainly occurs in the UV-VIS region, therefore a dopant emitting in the near infrared may be suitable for an optical discrimination of the stem effect. In this work, the RL and dosimetric properties of Yb-doped silica optical fibers, produced by sol-gel technique, are studied, together with the methods and instruments to achieve an efficient optical detection of the Yb3+ emission, characterized by a sharp line at about 975 nm. The results demonstrate that the RL of Yb3+ is free from any spectral superposition with the spurious luminescence. This aspect, in addition with the suitable linearity, reproducibility, and sensitivity properties of the Yb-doped fibers, paves the way to their use in applications where an efficient stem effect removal is required.

Color Analysis of Periimplant Soft Tissues Focusing on Implant System: A Case Series

Purpose: To assess the impact of implant system on color harmonization of periimplant mucosa. Materials and Methods: In this case series, color of periimplant mucosa was compared with color of natural tooth gingiva. Seventeen intercanine implants were analyzed (11 bone level [BL], 6 tissue level [TL] implants). Colorimetric data, at 2, 4, and 6 mm from gingival margin, were collected through fiber optics reflectance spectroscopy, and color differences calculated as &Dgr;E. Dentists, dental students, and lay people, in blind, performed an additional visual color analysis on clinical images. Results: Independently from implant system, the color of periimplant mucosa was significantly different from gingiva (&Dgr;E = 8.2 ± 0.7), resulting darker at L* comparison (P ⩽ 0.05). TL periimplant mucosa showed higher &Dgr;E than BL (9.0 ± 1.0 vs 6.6 ± 0.8, respectively; P ⩽ 0.05). Observers correctly identified where the implant was placed in about half of the cases, with no significant difference between implant systems. Conclusion: Within the limitations of this study, the color of periimplant soft tissues appears different from gingiva, at spectroscopic analysis. Color discrepancy results higher in the presence of TL implants than in BL implants, although the difference may not be clinically significant.

Bilateral asymmetry of skin temperature is not related to bilateral asymmetry of crank torque during an incremental cycling exercise to exhaustion

Although moderate relationships (|r| ∼ 0.5) were reported between skin temperature and performance-related variables (e.g., kinetic), it remains unclear whether skin temperature asymmetry reflects muscle force imbalance in cycling. Therefore, the aim of this study was to assess whether a relationship exists between kinetic and thermal asymmetry during a fatiguing exercise. Ten elite cyclists were enrolled and tested on a maximal incremental cycling test. Peak crank torques of both legs were obtained at the initial and final workload. Likewise, bilateral skin temperatures were recorded before and after exercise. Asymmetric indexes were also calculated for kinetic (AIK) and skin temperature (AIT) outcomes. The bilateral peak crank torques showed a larger difference at the final compared to the initial workload (p < 0.05) of the incremental exercise. Conversely, the bilateral skin temperature did not show any differences at both initial and final workload (p > 0.05). Additionally, trivial relationships were reported between AIK and AIT (−0.3 < r < 0.2) at the initial and final workload. The obtained results showed that changes in bilateral kinetic values did not reflect concurrent changes in bilateral skin temperatures. This finding emphasizes the difficulty of associating the asymmetry of skin temperature with those of muscle effort in elite cyclists. Lastly, our study also provided further insights on thermal skin responses during exhaustive cycling exercise in very highly-trained athletes.

Facial asymmetry in the resting state reflects anxiety status on young males

ABSTRACT Facial asymmetry is considered a marker of psychological, emotional and physiological distress, while anxiety is a behavioural, psychological and physiological response to a threat to well-being. Since individuals respond to anxiety with specific patterns (e.g., muscular tension), it is reasonable to hypothesize that anxiety could contribute to facial tension and therefore facial asymmetry. Instead, since facial asymmetry is perceived as “unpleasant” from peers, its presence may be a hindrance to social adaptation contributing to generate anxiety. In this study, we investigated whether resting facial asymmetry and anxiety are associated in young population. Full frontal facial photographs of 56 Caucasian males were taken in resting state to obtain indices of asymmetry in six facial landmarks. Anxiety status was assessed using the State-Trait Anxiety Inventory (STAI-Y). Analysis of the face showed that asymmetry and laterality of specific facial landmarks were associated with anxiety. State anxiety was associated with eyebrow and lateral angle of the eye, while trait anxiety was associated with eyebrow and lateral angle of the mouth. Moreover, as compared with contralateral landmarks, the left landmarks were lifted/expanded in subjects with elevated trait/state anxiety, whereas the right landmarks were lifted/expanded in subjects with low-trait/state anxiety.

Looking for Common Fingerprints in Leonardo’s Pupils Using Nondestructive Pigment Characterization

Non-invasive, portable analytical techniques are becoming increasingly widespread for the study and conservation in the field of cultural heritage, proving that a good data handling, supported by a deep knowledge of the techniques themselves, and the right synergy can give surprisingly substantial results when using portable but reliable instrumentation. In this work, pigment characterization was carried out on 21 Leonardesque paintings applying in situ X-ray fluorescence (XRF) and fiber optic reflection spectroscopy (FORS) analyses. In-depth data evaluation allowed to get information on the color palette and the painting technique of the different artists and workshops . Particular attention was paid to green pigments (for which a deeper study of possible pigments and alterations was performed with FORS analyses), flesh tones (for which a comparison with available data from cross-sections was made), and ground preparation.

Heat Diffusion in Klinker Facade: The Study Case of a Gio Ponti Building

The researchers focus on the IRT procedure of heat diffusion in ceramic finishing materials of contemporary architecture. The aim of the research is the development of a method for the thermal characterization of clinkers, a very common ceramic finishing material of buildings. The first experimental phase was performed in laboratory on clinkers of different shapes, thickness, colors, and glazing surface. The researchers determined two characteristic parameters related to thickness and thermal conductivity, by the interpolation of the heating curve in function of time with an analytical curve (resulted from a particular solution of Fourier’s equation). This curve allows to obtain a parameter characteristic of the material of the specimens under investigation. At present time, the researchers have been studying the correlation between this parameter and the damage level in the specimens; they will be testing the model on real-scale study cases in the second experimental phase.