Study of water mass transfer dynamics in frescoes by dielectric spectroscopy

The knowledge of moisture content (MC) is essential for determining the state of preservation of various types of hand-work: from building materials, such as bricks and concrete, to objects of artistic value, in particular frescoes and mural paintings. In all the above, moisture is the primary source of damages, as it affects the durability of porous materials. Dielectric properties of porous materials are strongly affected by the presence of water, suggesting dielectric spectroscopy as a suitable non-invasive diagnostic technique. The development of a quantitative relationship between MC and permittivity requires to investigate the dynamics of water mass transfer in porous media, and to determine its effect on the dielectric properties. In this paper a coupled mass transfer/dielectric problem is introduced and solved numerically, based on a finite element model. Results are compared to experimental dielectric measurement performed on plaster samples by the open coaxial method. The application of the dielectric technique to frescoes monitoring is proposed, showing the results obtained in an on-site study

Procedura per la valutazione dell'emissione di campi EM da un apparato per ipetermia con componente diatermica a 434.0 MHz e verifica del rispetto degli standard

The objective of this technical report is to establish a measurement procedure and/or measurement protocol in order to characterize the electromagnetic, electric and/or magnetic field sources at the workplaces, particularly in hospitals and in medical environmental. In this particular cases the exposure to electromagnetic fields involve workers, in-patients and their parents, and the devices and medical equipments. For the workers case we refer on the D.Lgs 81/2008 which acknowledges the European Directive 2004/40/EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (electromagnetic fields). For the in-patients the risk-benefit evaluation for exposure to electromagnetic fields is to advantage of benefit, except particular situations. For the parents of the in-patients we apply the standard fixed by the italian law (DPCM 8 Luglio 2003 “Fissazione dei limiti di esposizione, dei valori di attenzione e degli obiettivi di qualità per la protezione della popolazione dalle esposizioni a campi elettrici, magnetici ed elettromagnetici generati a frequenze comprese fra 100 kHz e 300 GHz”) For the devices and the medical equipments we refer to the CEI EN 60601-1-2. The standard fixes the electromagnetic immunity limits to 10 V/m for life-supporting equipments and systems and to 3 V/m for no life-supporting equipments and systems An instrument device for hyperthermia (Delta, Easytech Srl) has been chose as case-study for test the proposed measurement procedure. This instrument device is used in medical environmental to treatment of the pathologies of the locomotor apparatus. Its operating frequency is in ISM band (433.05÷434.79 MHz)

HKUST-1-Doped High-Resolution Volume Holographic Gratings

We report on transmission holographic gratings doped with metal organic frameworks (MOFs). As a first attempt, we focused on MOF-199, also known as HKUST-1, which is an efficient adsorbent of VOCs. HKUST-1 is not soluble in the pre-polymerized holographic mixture. For this reason, samples containing HKUST-1 show high light scattering. In this work, the recording of HKUST-1-doped one-dimensional transmission phase gratings is demonstrated. The optical properties of the recorded structures, such as diffraction efficiency and average refractive index changes, are reported by using angular analysis measurements. A first attempt to demonstrate the possibility of using the doped gratings as sensors is also reported

Optical devices provide unprecedented insights into the laser cleaning of calcium oxalate layers

Abstract Calcium oxalates are insoluble colorless or whitish salts constituting noble patina, on both natural and artificial stone artworks' surfaces, the presence of which is extremely valued. The oxalates are not considered detrimental to the substrate, however, being often accompanied by other substances such as gypsum, silicates, and pigmented particles. They may form very adherent, relatively thick and colored layers creating disfiguring effects and hindering legibility of the pictorial surface. For this reason it may be appropriate to diminish their thickness, but patina's partial preservation is particularly required calling for extremely gradual and controllable cleaning approach. Thinning of calcium oxalate patina from a detached 16th century fresco (from Sansepolcro) was performed through the use of laser (Nd:YAG and Er:YAG) systems and chemical means (Carbogel loaded 5 wt.% of tetrasodium EDTA). Optical coherence tomography (OCT), providing a non-invasive stratigraphic cross-section of the examined surface, allowed to distinguish the oxalate from the underlying original layers and therefore to have an overview about its distribution, to numerically evaluate patina's thickness range and to provide the information on the amount of the material both removed and left on the artwork's surface. Laser scanning conoscopic microprofilometry allowed for a high-density sampling of the artwork's surface providing a three-dimensional model of the surface pattern. The obtained 3D models were used to estimate the amount of material removed and to compare them with those provided by OCT. The successful exploitation of the proposed exceptional cleaning monitoring methodology may be seen as an innovative and valid support for the restorers in the conservation of mural painting or other surfaces covered by oxalate layers and may pilot more targeted, cautious and respectful cleaning intervention

Valutazione del rischio elettromagnetico ai sensi del D.Lgs. 81/2008 presso l\u27Azienda Ospedaliera Mellino Mellini Chiari (Brescia)

.La relazione riferisce i risultati della campagna di misura effettuata nei giorni dal 6 al 9 giugno 2011 e successivamente il 4 e il 6 luglio 2011. La campagna ? stata preceduta da un sopralluogo (21 marzo 2011) alle strutture di competenza dell\u27Azienda Mellino Mellini (Chiari, Iseo, Rovato, Palazzolo ed Orzinuovi) per la definizione delle azioni da intraprendere per la valutazione del rischio elettromagnetico in conformit? al D.Lgs. 81/2008. Pi? specificatamente gli obiettivi della campagna di misura sono stati i seguenti. Misura dei campi elettromagnetici (EM) in punti predefiniti per la determinazione dei livelli di campo EM presenti. Determinazione dei campi elettrici, magnetici ed elettromagnetici emessi da apparecchiature elettromedicali quali magnetoterapia e radarterapia . Misura dei campi magnetici (in particolare induzione magnetica) presenti nei locali tecnici quali cabina elettrica e impianti di condizionamento. Valutazione dell\u27intensit? dell\u27induzione magnetica all\u27interno e in prossimit? di incubatrici e culle termiche (Chiari e Iseo). Valutazione delle specifiche tecniche di elettrobisturi (Blocco Operatorio di Iseo). Caratterizzazione della presenza di eventuali interferenze EM dovute alla rete wireless (reparto di terapia intensiva di cardiologia di Chiari) o da disturbi EM presenti su apparecchiature per diagnostica (neurologia di Chiari)

Procedura per la misura di Campi EM emessi da impianti Radar utilizzabile in campagne di Sorveglianza Fisica Ambientale

.

Misure sul Radar di Maccarese (Fiumicino -Roma)

.