28,358 research outputs found
Historical damage pattern and causes of differential damage: an approach based on combining geophysical prospecting, geological and historical-technical data
No full textWe describe a multidisciplinary and interdisciplinary method to analyse the causes of differential macroseismic effects caused by an earthquake in a historical town. We illustrate the method with a case study based on analysing the damage caused by the 1930 Irpinia earthquake (Me=6.7) in Melfi, a town in southern Italy. A damage pattern map was already available for this site. To understand the anomalies of Melfi damage, we used an integrated approach that combines geological surveys, geophysical prospecting and analysis of unpublished technicalhistorical data. Geo-electrical prospecting was adopted to infer the geological set-up and to estimate the thickness of shallow deposits. The results of the geophysical surveys were compared with detailed geological information derived from both in situ surveys and boreholes. Finally, cross-correlation among these data and technical reports coeval to the earthquake allowed us to create a complete picture of the possible causes of uneven damageWe describe a multidisciplinary and interdisciplinary method to analyse the causes of differential macroseismic effects caused by an earthquake in a historical town. We illustrate the method with a case study based on analysing the damage caused by the 1930 Irpinia earthquake (MeCombining double low line6.7) in Melfi, a town in southern Italy. A damage pattern map was already available for this site. To understand the anomalies of Melfi damage, we used an integrated approach that combines geological surveys, geophysical prospecting and analysis of unpublished technical-historical data. Geo-electrical prospecting was adopted to infer the geological set-up and to estimate the thickness of shallow deposits. The results of the geophysical surveys were compared with detailed geological information derived from both in situ surveys and boreholes. Finally, cross-correlation among these data and technical reports coeval to the earthquake allowed us to create a complete picture of the possible ..
Pin-hole array production and detailed data analysis for advanced single-shot X-ray imaging of laboratory plasmas
No full textLaser produced plasmas offer the unique opportunity to investigate physical mechanisms working at extremely high field in pulsed regime [1] (Gizzi et al., 2009). Future large scale infrastructure like HiPER and ELI may open new frontiers of knowledge in this way. Technologies needed for improving diagnostic in this field have a strong impact on a wide range of multi-disciplinary applications as for compact plasma-based accelerators [1,2] (Gizzi et al., 2009; Betti et al., 2009) laser fusion oriented experiments, three-dimensional microscopy and lithography. As an example the X-ray imaging, being a powerful diagnostic tool for deep investigation on different variety of laser produced plasma, has obtained a grooving effort in recent years. Large scale facilities working in single-pulse regime for laser fusion oriented experiments have evidenced the necessity to obtain spectrally resolved X-ray images of produced plasmas in a single shot. By combining the charge coupled devices (CCD) based single-photon detection technique with a pin-hole array (PHA) a new diagnostic technique was developed, as shown in recent experiments related to the European HiPER project [3] (Labate et al., 2009). Here we qualitatively describe the PHA production process on a heavy metal substrate by means of SEM images that show an internal diameter on the micrometer scale and an aspect ratio of about 20. The characterization of the X-ray contrast up to 90 keV is presented. The data analysis of the X-ray photons interaction on CCD, for spectrum reconstruction up to high energy, is described [4] (Levato et al., 2008). (C) 2010 Elsevier B.V. All rights reserved. RI Gizzi, Leonida/F-4782-201
Multi-Scale Monitoring of Rupestrian Heritage: Methodological Approach and Application to a Case Study
No full textMost of the artistic heritage in the Mediterranean basin is hosted in rupestrian hypogeum whose peculiarity is given by the presence of at least one open side, which makes them particularly sensitive to meteorological conditions. This makes mandatory the monitoring of both indoor and outdoor environmental parameters to analyze the cause–effect relationship between microclimatic inside and outside the hypogeum. The paper proposes a spatial and temporal multi-scale methodological approach applied to a rupestrian church in Matera, which hosts precious wall paintings, particularly vulnerable to the effects of environmental parameters. The approach is based on the analysis of data acquired by three platforms: indoor, close-range outdoor, and outdoor data from a meteorological station and weather forecast from the COSMO 5 model. The method allowed to characterize the relationships between the indoor and outdoor parameters at different spatial and temporal scales. The results showed a significant correlation between the parameters, thus opening new opportunities for the monitoring of the rupestrian heritage based on the use of data systematically available, such as those from meteorological stations and meteorological forecast
Historical earthquakes and damage patterns in Potenza (Basilicata, Southern Italy)
No full textThis paper analyzes three historical seismic damage patterns in Potenza, the main town of the Basilicata Region,
in Southern Italy. We refer to the 1826, 1857 and 1930 earthquakes, which hit the town with intensities ranging
from VI-VII to VIII-IX MCS. In order to depict the seismic effects, we analyzed original documents, most of
them never consulted before. The events have been located on an urban map of Potenza dating back to 1875.
This research represents the starting point for further investigations, with the goal of highlighting the causes of
the ‘anomalies’ in the distribution of the effects.JCR Journalope
Letter from Carl Hayden to Henry F. Ashurst
No full textLetter describing three enclosures, a letter from F. M. Gold, Carl T. Hayden's reply to Gold's letter, and a copy of a bill introduced by Cameron
Letter from A. F. Potter to Carl Hayden
No full textLetter from A. F. Potter to Carl T. Hayden describing John H. Page's request to build a railway for the Canyon Copper Company as "impractical"
Effects of pacing site and stimulation history on alternans dynamics and the development of complex spatiotemporal patterns in cardiac tissue
No full textAlternans of action potential duration has been associated with T-wave alternans and the development of arrhythmias because it produces large gradients of repolarization. However, little is known about alternans dynamics in large mammalian hearts. Using optical mapping to record electrical activations simultaneously from the epicardium and endocardium of 9 canine right ventricles, we demonstrate novel arrhythmogenic complex spatiotemporal dynamics. (i) Alternans predominantly develops first on the endocardium. (ii) The postulated simple progression from normal rhythm to concordant to discordant alternans is not always observed; concordant alternans can develop from discordant alternans as the pacing period is decreased. (iii) In contrast to smaller tissue preparations, multiple stationary nodal lines may exist and need not be perpendicular to the pacing site or to each other. (iv) Alternans has fully three-dimensional dynamics and the epicardium and endocardium can show significantly different dynamics: multiple nodal surfaces can be transmural or intramural and can form concave/convex surfaces resulting in islands of discordant alternans. (v) The complex spatiotemporal patterns observed during alternans are very sensitive to both the site of stimulation and the stimulation history. Alternans in canine ventricles not only exhibit larger amplitudes and persist for longer cycle length regimes compared those found in smaller mammalian hearts, but also show novel dynamics not previously described that enhance dispersion and show high sensitivity to initial conditions. This indicate some underlying predisposition to chaos and can help the design of new drugs and devices controlling and preventing arrhythmic events
Diffraction and polarization properties of POLICRYPS permanent and switchable gratings
No full textAn experimental and theoretical study is presented on a novel class of electrically switchable diffraction gratings, formed by alternated stripes of polymer and liquid crystal (LC) called POLICRYPS (POlimer LIquid CRYstal Polymer Slides) [1]. The measurement of the diffraction efficiency versus the angle of incidence was performed for both p and s polarized probe beams at two wavelengths of 632.8 nm and 1550 nm. In particular infrared diffraction properties are interesting for possible applications of POLICRYPS as optical switches for fiber optic communication systems as demonstrated in a previous work [2]. The sample under test consisted of a 11.5 μm thick cell made of coupled ITO coated glass substrates filled with a mixture of 30%wt of nematic LC (NLC) 5CB and 70%wt of UV curable pre-polymer NOA61. A grating with a period of about 1.38 μm was written by laser curing at wavelength of 351 nm. A strong modulation of the refractive index across the sample is due to the NLC director which is oriented perpendicularly to the polymer stripes on the cell surface, and hence parallel to the wave vector of the impinging optical field. This geometry yields a high mismatch between the refractive index of NOA-61 (nP= 1.56) and the extraordinary refractive index of 5CB (ne= 1.7057) at 632.8 nm and T=25 °C. Diffraction efficiencies of about 95% at 632.8 nm and of about 40% at 1550 nm for a p-polarized beam probe were detected. Diffraction efficiencies below 8% were measured for an s-polarized beam probe. The grating can be switched off by applying an external electric field due to the matching between the refractive index of the liquid crystal and the polymer one. The presence of a threshold voltage for the decrease of the diffraction efficiency is due to the balancing between the dielectric torque and the elastic torque acting on the director of NLC molecules confined among the polymer stripes. At the Bragg angle the grating diffraction efficiency can be switched below 5% by applying an electric field of 5 V/μm at 632.8 nm and of 8 V/μm at 1550 nm. The coupled mode theory extended to thick anisotropic materials [3] has been used to fit the diffraction angular spectra at both wavelengths. Agreement between theoretical and experimental results for both polarizations has been achieved by including a statistical fluctuation of the LC molecule axis orientation with a Gaussianlike distribution respect to the grating vector [4].
References
[1] R. Caputo, A. V. Sukhov, and C. Umeton, Mol. Cryst. Liq. Cryst., Vol. 372, pp. 263-274, 2001.
[2] R. Asquini, A. d’Alessandro, C. Gizzi, P. Maltese, R. Caputo, A. V. Sukhov, C. Umeton, A. Veltri, Mol. Cryst. Liq. Cryst., 2003, in press.
[3] G. Montemezzani and M. Zgonik, Phys. Rev. E, Vol. 55, pp. 1035-1047, 1997.
[4] R. Sutherland, J. Opt. Soc. Am. B, Vol. 19, pp. 2995-3003, 2002
DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire
No full textThe majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
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