Reorientation dynamics in thin glassy films

We present a study of orientational relaxation dynamics in thin films of a low-molecular-weight glass-former as a function of temperature and film thickness. The relaxation is probed by second-harmonic generation after release of a poling electric field. From the measured decays of the second-harmonic signal and their fitting with a stretched exponential, we can determine the distribution of relaxation times in the system. As temperature decreases from above the glass transition, we observe that the width of the distribution first increases under confinement, but that deeper in the glassy state, confinement has no effect anymore on the dynamics.Comment: 10 pages, including 12 figures, RevTeX

Giurisdizionalismi. Le politiche ecclesiastiche negli stati minori della penisola italiana in età moderna

I contributi riuniti nel volume intendono dar conto delle “prassi” giurisdizionaliste che la documentazione d’archivio fa emergere in ambiti geopolitici definibili come “minori”. Il panorama mosso e frastagliato che tra Cinque e Settecento offre la penisola italiana, se è pur vero che sembra non evidenziare linee nette di conflittualità marcata, presenta tuttavia una dialettica di lungo periodo che la paziente ricerca negli archivi ha potuto finalmente restituire, rendendo in tal maniera necessaria una meditata revisione di interpretazioni storiografiche ormai datate

Basal Cell Carcinoma Masked in Rhinophyma

Rhinophyma, the advanced stage of rosacea, is a lesion characterized by progressive hypertrophy and hyperplasia of sebaceous glandular tissue, connective tissue, and blood vessels. Rhinophyma can lead to a significant facial disfigurement and severe emotional distress, but it is not only an aesthetic problem, since rare cases of simultaneous presence of malignant tissue are described in the literature. The case of an 84-year-old farmer affected by basal cell carcinoma (BCC) and diagnosed in the context of rhinophyma is presented. The anatomical distortion produced by the chronic inflammation and fibrous scarring makes the BCC diagnosis difficult and uncertain. The histological examination of the entire mass and its margins is fundamental. A partial biopsy can lead to a false negative result, and the histological examination must be repeated intra- or postoperatively

The Candoglia Marble and the “Veneranda Fabbrica del Duomo di Milano”: A Renowned Georesource to Be Potentially Designed as Global Heritage Stone

Marbles from Alpine area have been widely employed to build and decorate masterpieces and buildings which often represent the cultural heritage of an area (statuary, historic buildings and sculptures). Candoglia marble, object of the present research, is one of the most famous and appreciated marbles from Alpine area; it has been quarried since Roman times in the Verbano-Cusio-Ossola (VCO; Piemonte—NW Italy) extractive area. Candoglia Marble outcrops are present as lenses within the high-grade paragneisses of the Ivrea Zone, a visible section of deep continental crust characterised by amphibolite- to granulite-facies metamorphism (Palaeozoic period). Candoglia calcitic marble (80–85% CaCO3 and the 15–20% other minerals) shows a characteristic pink to gray colour and a coarse-grained texture (>3 mm): frequent centimetre-thick dark-greenish silicate layers (mainly represented by diopside and tremolite) characterize the texture of the marble. It has been largely used in local rural constructions and historical buildings, but its most famous application has been (and still is) for the “Duomo di Milano” construction (fourteenth century). The Veneranda Fabbrica del Duomo di Milano carried out the anthropogenic activities dealing with the Candoglia marble exploitation; it has to be highlighted that the company have managed the Marble exploitation during the last seven centuries and that the quarry itself is a tangible sign of the development of extraction and heritage in the VCO area. Candoglia marble can be recognized as a significant example of a “Global Heritage Stone Resource”: its exploitation from quarry to building (the Duomo di Milano) well represents the close correlation between stone and cultural heritage, between georesources and humankind development

CO2 Emission from two old mine drillings (Mt. Amiata, Central Italy) as a possible example of storage and leakage of deep-seated CO2

CO2 Emission from two old mine drillings (Mt. Amiata, Central Italy) as a possible example of storage and leakage of deep-seated CO

Origin of the gases released from the Acqua Passante and Ermeta wells (Mt. Amiata, central Italy) and possible environmental implications for their closure

The Mt. Amiata volcano (Tuscany, central Italy) hosts the second largest geothermal field of Italy. Its SW and NE sectors are characterized by the presence of several CO2-rich (mayor que95% by vol.) gas discharges. An intense Hg mining activity had taken place from the 19th century up to the end of the ?70s, particularly close to Abbadia San Salvatore, during which two drillings (Acqua Passante and Ermeta) intercepted a CO2-rich gas fertile horizon. The related gases are emitted in the atmosphere since 1938 and 1959, respectively, causing severe concerns for the local air quality. In this work the results of a geochemical and isotopic survey carried out on these gas emissions from March 2009 to January 2014 are presented. CO2 fluxes from both the two wells and soil from an area of about 653,500 m2 located between them were measured. The two wells are emitting up to 15,000, 92 and 8 tons y-1 of CO2, CH4 and H2S, respectively, while the computed soil CO2 output was estimated at 4,311 ton y-1. The spatial distribution of the CO2 soil flux suggests the presence of preferential patterns, indicating sites of higher permeability. Since the local municipality is evaluating the possibility to plug the Ermeta vent, a temporarily closure should first be carried out to test the possible influence of this operation on the diffuse soil degassing of deep-originated CO2 in the surrounding area. This implies that diffuse soil gases should carefully be monitored before proceeding with its definitive closure

Multi-axial stress sensor for structural health monitoring

All civil structures experience aging and deteriorate with time. To ensure structural integrity, civil structures should thus be equipped with sensors for Structural Health Monitoring (SHM) with the aim of developing automated monitoring systems and facilitate inspections for damage detection. Nowadays, optical sensors and accelerometer are mostly used for SHM [1]. However, it has been shown that stress sensors could improve the reliability of monitoring systems as well as the accuracy of damage identification [2]. Of course, these stress sensors should be low cost to be spread within the structure. MEMS technology is therefore the most promising technology. Existing MEMS stress sensors have very limited full-scale and they are unable to separate the contributions of normal and shear stresses at material-package interface. This paper presents a multi-axial stress sensor based on thick film piezo-resistive ink [3] that is capable of measuring both the out-of-plane and the in-plane internal stresses of the structures being monitored. By decoupling the two components of stress, the sensor is insensitive with respect to the variation of the surrounding material properties and boundary/installation conditions. The proposed stress sensor consists of three layers of ceramics, two thick protection layers and a thin middle layer bonded together by means of a bonding glass. The top surface of the middle layer contains the piezo-resistive gauges that are connected to form two Wheatstone bridges: one bridge senses in-plane strains and the other one senses both in-plane and out-of-plane strains [4]. The design of the sensor and the position of the sensing elements were optimized by means of a commercial Finite Element software. A series of prototypes were produced and tested in laboratory by means of compression tests, imposing different boundary conditions and materials, up to a compression force of 5 kN that corresponds to a normal pressure of 10 MPa. Also, the influence of working temperature was assessed. By linearly combining the two bridge outputs, the influence of boundary conditions on the compression stress component can be minimized. Inserting the sensor in standardized concrete samples having size of 15x15x15 cm the influence of inclusions close to the sensor can be also assessed. Again, the influence of inclusions on the compression stress is shown to be negligible unless the inclusion is very close to the 3D resistors

Caratterizzazione in microscopia SEM-EDS del cemento endodontico MTA: un confronto tra diversi prodotti

RiassuntoObiettiviValutare le caratteristiche microscopiche dei cementi endodontici MTA disponibili in commercio e di un cemento di Portland.Materiali e metodiAnalisi su quattro varietà di MTA: Ogna Aureoseal®, Proroot white MTA®, Angelus white e gray MTA® e un cemento di Portland. I campioni, previo esame in diffrazione X, sono stati consolidati; i provini a cemento solidificato sono stati inglobati in una resina epossidica e lucidati in superficie: questo ha permesso un'osservazione SEM-EDS per evidenziarne la struttura e la natura chimica e mineralogica.RisultatiLe analisi mostrano significative differenze tra i vari tipi di MTA presi in esame e tra questi e il cemento di Portland usato come riferimento.I cementi utilizzati a scopo odontoiatrico hanno granuli di minori dimensioni, una maggiore idratazione e un minor contenuto di ferro e zolfo. Tra i costituenti mineralogici caratteristici del MTA si riscontrano agenti radio-opacizzanti (Bi2O3 e CaWO4). Una sostanziale differenza tra i cementi MTA è la quantità variabile nel contenuto di magnesio e alluminio che, dopo il consolidamento, presentano una granulometria inferiore nei campioni Ogna Aureoseal® e Proroot white MTA®; la presenza di apatite e tungstato di calcio (CaWO4) è invece caratteristica del cemento MTA Ogna Aureoseal®.ConclusioniLe differenze tra i campioni MTA e tra questi e il cemento di Portland sono significative sia a livello di tessitura microscopica sia di composizione chimica.AbstractObjectivesTo determine the mineralogical, chemical, and microtextural differences between commercially available MTA products, clarifying common differences with Portland and between each other.Materials and methodsThe study was done on four commercially available MTA cements, that is Ogna Aureoseal®, Proroot white MTA®, Angelus white and gray MTA® and on a commercial Portland cement. After preliminary X-ray diffraction characterization of the powder, the samples were consolidated following the same procedure used in clinical practice. The consolidated material was embedded in epoxy and polished, and subsequently investigated, by means of SEM-EDS analysis of back-scattered electron images on all samples and of quantitative compositional mapping on MTA.ResultsThe MTA and Portland cements differ for the grain size, the hydration rate, and homogeneity of the set products, and for lower Fe and S content in MTA. Previously reported presence of opacizing agents (Bi2O3 and CaWO4) was confirmed in all samples, whereas low Al content was not observed in all MTA. Although the MTA products are all mainly composed by di-calcium and tri-calcium silicates, the post-setting texture and the chemical and mineralogical constitution differ. Finer texture was observed in Ogna Aureoseal® and Proroot white MTA®; in Ogna Aureoseal® the presence of apatite and Ca-tungstate was reported; Mg and Al content changed in samples, following the clinker composition.ConclusionsSignificant differences exist between Portland cement and MTA, but also among different MTA formulations. MTA products can be classified as a form of Portland cement, specifically modified for dentistry purposes