2,608 research outputs found

    The Contribution of Universities to Growth: Empirical Evidence for Italy

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    New entrepreneurial ventures may represent a viable and effective mechanism to transform academic knowledge into regional economic growth. We test this notion for the Italian provinces between 2001 and 2006. We evaluate three outputs of academic activities: teaching, research and Intellectual Property Rights (IPR) activities management. New ventures may be able to transform the mentioned outputs into improved economic performance. The findings show that the effects of academic outputs on provincial economic growth (all sectors) are appreciable when they are associated with sustained entrepreneurial activities in the province. It suggests that academic inquiry may provide new ventures with valuable commercial opportunities overseen by established companies.

    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, ”-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, ”-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

    Testing Local Lorentz and Position Invariance and Variation of Fundamental Constants by searching the Derivative of the Comparison Frequency Between a Cryogenic Sapphire Oscillator and Hydrogen Maser

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    The cryogenic sapphire oscillator (CSO) at the Paris Observatory has been continuously compared to various Hydrogen Masers since 2001. The early data sets were used to test Local Lorentz Invariance in the Robertson-Mansouri-Sexl (RMS) framework by searching for sidereal modulations with respect to the Cosmic Microwave Background, and represent the best Kennedy-Thorndike experiment to date. In this work we present continuous operation over a period of greater than six years from September 2002 to December 2008 and present a more precise way to analyze the data by searching the time derivative of the comparison frequency. Due to the long-term operation we are able to search both sidereal and annual modulations. The results gives P_{KT} = \beta_{RMS}-\alpha_{RMS}-1 = -1.7(4.0) \times 10^{-8} for the sidereal and -23(10) \times 10^{-8} for the annual term, with a weighted mean of -4.8(3.7) \times 10^{-8}, a factor of 8 better than previous. Also, we analyze the data with respect to a change in gravitational potential for both diurnal and annual variations. The result gives \beta_{H-Maser} - \beta_{CSO} = -2.7(1.4) \times 10^{-4} for the annual and -6.9(4.0) \times 10^{-4} for the diurnal terms, with a weighted mean of -3.2(1.3) \times 10^{-4}. This result is two orders of magnitude better than other tests that use electromagnetic resonators. With respect to fundamental constants a limit can be provided on the variation with ambient gravitational potential and boost of a combination of the fine structure constant (\alpha), the normalized quark mass (m_q), and the electron to proton mass ratio (m_e/m_p), setting the first limit on boost dependence of order 10^{-10}.Comment: Fixed typo

    Sub-100 attoseconds optics-to-microwave synchronization

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    We use two fiber-based femtosecond frequency combs and a low-noise carrier suppression phase detection system to characterize the optical to microwave synchronization achievable with such frequency divider systems. By applying specific noise reduction strategies, a residual phase noise as low as -120 dBc/Hz at 1 Hz offset frequency from a 11.55 GHz carrier is measured. The fractional frequency instability from a single optical-to-frequency divider is 1.1E-16 at 1 s averaging down to below 2E-19 after only 1000 s. The corresponding rms time deviation is lower than 100 attoseconds up to 1000 s averaging duration.Comment: 4 pages, 3 figure
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