3,308 research outputs found

    Characterization and digital restauration of XIV-XV centuries written parchments by means of non-destructive techniques. Three case studies

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    Parchment is the primary writing medium of the majority of documents with cultural importance. Unfortunately, this material suffers of several mechanisms of degradation that affect its chemical-physical structure and the readability of text. Due to the unique and delicate character of these objects, the use of nondestructive techniques is mandatory. In this work, three partially degraded handwritten parchments dating back to the XIV-XV centuries were analyzed by means of X-ray fluorescence spectroscopy, µ-ATR Fourier transform infrared spectroscopy, and reflectance and UV-induced fluorescence spectroscopy. 'e elemental and molecular results provided the identification of the inks, pigments, and superficial treatments. In particular, all manuscripts have been written with iron gall inks, while the capital letters have been realized with cinnabar and azurite. Furthermore, multispectral UV fluorescence imaging and multispectral VIS-NIR imaging proved to be a good approach for the digital restoration of manuscripts that suffer from the loss of inked areas or from the presence of brown spotting. Indeed, using ultraviolet radiation and collecting the images at different spectral ranges is possible to enhance the readability of the text, while by illuminating with visible light and by collecting the images at longer wavelengths, the hiding effect of brown spots can be attenuated

    Characterization and digital restauration of XIV-XV centuries written parchments by means of non-destructive techniques. Three case studies

    Get PDF
    Parchment is the primary writing medium of the majority of documents with cultural importance. Unfortunately, this material suffers of several mechanisms of degradation that affect its chemical-physical structure and the readability of text. Due to the unique and delicate character of these objects, the use of nondestructive techniques is mandatory. In this work, three partially degraded handwritten parchments dating back to the XIV-XV centuries were analyzed by means of X-ray fluorescence spectroscopy, µ-ATR Fourier transform infrared spectroscopy, and reflectance and UV-induced fluorescence spectroscopy. 'e elemental and molecular results provided the identification of the inks, pigments, and superficial treatments. In particular, all manuscripts have been written with iron gall inks, while the capital letters have been realized with cinnabar and azurite. Furthermore, multispectral UV fluorescence imaging and multispectral VIS-NIR imaging proved to be a good approach for the digital restoration of manuscripts that suffer from the loss of inked areas or from the presence of brown spotting. Indeed, using ultraviolet radiation and collecting the images at different spectral ranges is possible to enhance the readability of the text, while by illuminating with visible light and by collecting the images at longer wavelengths, the hiding effect of brown spots can be attenuated

    Accuracy of three electronic apex locators in anterior and posterior teeth: an ex-vivo study.

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    Abstract Introduction: The aim of this study was to determine in anterior teeth, bicuspids, and molars (1) the accuracy of 3 different electronic apex locators (EALs) in detecting the apical foramen and (2) the accuracy of digital radiography in determining the working length (WL), compared with visible control under a microscope. Methods: By using radiovideography (RVG), we measured the lengths of 120 root canals with 3 different EALs (Endex, ProPex II, and Root ZX) and compared them with the actual lengths. The accuracy of EALs and RVG was related to each dental category. An endodontic training kit (Pro-Train) was used during experimental procedures. Results: Statistical analysis showed that the 3 EALs and RVG were less accurate in anterior teeth and molars than in bicuspids. The paired-sample t test showed no statistically significant difference between mesiodistal plane and buccolingual plane digital radiography in all groups. Conclusions: The 3 EALs tested were more accurate in detecting the apical foramen in bicuspids than in both molars and anterior teeth. Radiographic measurements were not reliable for determining WL in all dental groups in both radiographic planes. (J Endod 2011;37:684–687

    Precisione nella determinazione della lunghezza di lavoro mediante localizzatori elettronici d’apice, radiologia digitale e prova visiva: presentazione di una nuova metodica sperimentale di indagine – uno studio ex-vivo. Exact determination of the working length by electronic apex locators, digital radiology, and visual test: presentation of a new experimental research strategy – an ex-vivo study.

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    Abstract Objectives: This study compared: 1) the accuracy of three different electronic apex locators (EALs) in detecting the apical foramen ex-vivo under clinical conditions; 2) the accuracy of digital radiography and EALs in determining the K-file position in the root canal; 3) the accuracy of two different radiographic planes; (4) the precision of #10, #15, and #20 K-files in electronic measurements; 5) the precision of EALs in relation to the dental anatomy classification (anterior, bicuspids, and molars). Materials and methods: The length of 101 extracted human teeth was measured with three different EALs (Endex, Propex II and Root ZX), with RVG and compared to the actual length. Experimental procedures were performed using an endodontic training kit (Pro-Train). Results: The statistical analysis showed that Endex and Propex II were more accurate than Root ZX in determining the working length (WL). The t-test showed no statistically significant difference of accuracy between the two radiographic planes examined. The t-test showed no significant difference between the three different K-file size measurements. EALs and RVG are less accurate in anterior teeth. Conclusions: To prevent overestimation of the root canal length using the EALs tested, 1 mm should be subtracted from the measurement on the ‘‘APEX’’ mark. Instrument sizes did not affect the accuracy of EALs. EALs showed to be more accurate in determining the WL than RVG. 2011 Societa` Italiana di Endodonzia. Published by Elsevier Srl. All rights reserved

    The main critical issues of the gym environment in an Italian city

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    BACKGROUND: The lack of a consistent national regulation regarding gym facilities, combined with the growth and transformation of the world of fitness, has led to an uncontrolled situation, where, especially in metropolitan areas, low cost gyms are continuously popping up, often not respecting the structural and hygienic requirements. AIM OF THE STUDY: Objective of this study is to evaluate the results of a monitoring programme about the gym environment, to highlight the main critical issues. METHODS: In 2018 a randomized sample of 90 gyms was inspected in Milan, using a checklist with three sections of inquiry and the resulting data were analysed through a series of multivariate regression models. RESULTS: As per the various aspects analysed, many outcomes with low scores concerned franchised gyms, which have shown to be unsatisfactory in many respects; in addition, the lack of L. pneumophila risk containment procedures has been observed in the facilities without a swimming pool, compared to those with it. CONCLUSIONS: The study results offer a clear picture of the gym environment, identifying many inadequacies for different hygienic and safety aspects; therefore, it has been possible to understand which issues need particular attention in order normalize the situation, which should be checked by future investigative steps

    Real time control of EC heating & current drive systems on TCV

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    The ability to control, in real time, the electron cyclotron heating & current drive systems for the control of MHD instabilities is particularly important for large tokamaks operating at high performance. Several algorithms have been developed and tested on TCV to explore possible control techniques, first in simple experiments to control the plasma current and elongation and subsequently in experiments to control the sawtooth instability and profile parameters. A summary of these experiments are presented in this paper together with the application of the break-in-slope technique as a possible real time calculation of the location of EC deposition

    Temporal response to harmonic driving in electroconvection

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    The temporal evolution of the spatially periodic electroconvection (EC) patterns has been studied within the period of the driving ac voltage by monitoring the light intensity diffracted from the pattern. Measurements have been carried out on a variety of nematic systems, including those with negative dielectric and positive conductivity anisotropy, exhibiting "standard EC" (s-EC), those with both anisotropies negative exhibiting "non-standard EC" (ns-EC), as well as those with the two anisotropies positive. Theoretical predictions have been confirmed for stationary s-EC and ns-EC patterns. Transitions with Hopf bifurcation have also been studied. While traveling had no effect on the temporal evolution of dielectric s-EC, traveling conductive s-EC and ns-EC patterns exhibited a substantially altered temporal behavior with a dependence on the Hopf frequency. It has also been shown that in nematics with both anisotropies positive, the pattern develops and decays within an interval much shorter than the period, even at relatively large driving frequencies.Comment: 19 pages, 5 figure
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