30 research outputs found

    Electrical and non electrical characteristics for the fast detection of high current free-burning arcs

    Get PDF
    To guarantee save and reliable operation of low voltage grid devices and to protect all devices from disturbance or damage, it is absolutely necessary to separate normal operation from fault state. A typical fault state with an enormous hazard potential is the arc fault. Due to the high level of energy involved, it can lead to the total write-off of affected devices and hence interrupt the energy supply (service). To prevent extensive consequences, there is a high demand to detect these error conditions and to terminate the fault state in a period of a few milliseconds. The analysis of typical electrical and non-electrical signals with numerical algorithms enables fast detection of arc faults

    FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes

    Get PDF
    [EN] A set of ancient Antoninianus silver coins, dating back between 249 and 274¿A.D. and minted in Rome, Galliae, Orient and Ticinum, have been characterized. We use, for the first time, a combination of nano-invasive (focused ion beam-field emission scanning electron microscopy-X-ray microanalysis (FIB-FESEM-EDX), voltammetry of microparticles (VIMP)) and destructive techniques (scanning electron microscopy (SEM-EDX) and electron microprobe analysis (EMPA)) along with non-invasive, i.e., micro-Raman spectroscopy. The results revealed that, contrary to the extended belief, a complex Ag-Cu-Pb-Sn alloy was used. The use of alloys was common in the flourishing years of the Roman Empire. In the prosperous periods, Romans produced Ag-Cu alloys with relatively high silver content for the manufacture of both the external layers and inner nucleus of coins. This study also revealed that, although surface silvering processes were applied in different periods of crisis under the reign of Antoninii, even during crisis, Romans produced Antoninianus of high quality. Moreover, a first attempt to improve the silvering procedure using Hg-Ag amalgam has been identified.Financial support was provided by Sapienza University of Rome (Ateneo funding, 2014 15) and Spanish projects CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P, which are supported with Ministerio de Economía, Industria y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (ERDF) funds, as well as project CTQ2017-85317-C2-1-P supported with funds from, MINECO, ERDF and Agencia Estatal de Investigación (AEI). PhD grants of the Department of Earth Sciences, Sapienza University of Rome, are gratefully acknowledgedDomenech Carbo, MT.; Di Turo, F.; Montoya, N.; Catalli, F.; Doménech Carbó, A.; De Vito, C. (2018). FIB-FESEM and EMPA results on Antoninianus silver coins for manufacturing and corrosion processes. Scientific Reports. 8. https://doi.org/10.1038/s41598-018-28990-xS8Doménech-Carbó, A., del Hoyo-Meléndez, J. M., Doménech-Carbó, M. T. & Piquero-Cilla, J. Electrochemical analysis of the first Polish coins using voltammetry of immobilized particles. Microchem. J. 130, 47–55 (2017).Di Turo, F. et al. Archaeometric analysis of Roman bronze coins from the Magna Mater temple using solid-state voltammetry and electrochemical impedance spectroscopy. Anal. Chim. Acta 955, 36–47 (2017).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. Dating Archeological Lead Artifacts from Measurement of the Corrosion Content Using the Voltammetry of Microparticles. Anal. Chem. 83, 5639–5644 (2011).Giumlia-Mair, A. et al. Surface characterisation techniques in the study and conservation of art and archaeological artefacts: a review. Materials Technology 25(5), 245–261 (2010).Robbiola, L. & Portier, R. A global approach to the authentication of ancient bronzes based on the characterization of the alloy–patina–environment system. Journal of Cultural Heritage 7, 1–12 (2006).Campbell, W. Greek and Roman plated coins, Numismatics Notes and Monographs 57, American Numismatic Society, New York (1933).Kallithrakas-Kontos, N., Katsanos, A. A. & Touratsoglou, J. Trace element analysis of Alexander the Great’s silver tetradrachms minted in Macedonia, Nuclear Instruments and Methods in Physics. Research B 171, 342–349 (2000).Catalli, F. Numismatica greca e romana. (Libreria dello Stato, 2003).Cope, L. H. The Metallurgical development of the Roman Imperial Coinage during the first five centuries. (Liverpool, 1974).Scriptores Historiae Augustae. Historia Augusta. (The Perfect Library, 2014).Vlachou-Mogire, C., Stern, B. & McDonnell, J. G. The application of LA-ICP-MS in the examination of the thin plating layers found in late Roman coins. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 265, 558–568 (2007).Keturakis, C. J. et al. Analysis of corrosion layers in ancient Roman silver coins with high resolution surface spectroscopic techniques. Appl. Surf. Sci. 376, 241–251 (2016).Ingo, G. M. et al. Roman sophisticated surface modification methods to manufacture silver counterfeited coins. Appl. Surf. Sci. 1–11, https://doi.org/10.1016/j.apsusc.2017.01.101 (2017).La Niece, S. In: La Niece S. & Craddock, P. (Eds), Metal, Plating and Platination, Butterworth–Heinemann, London, 1993, p. 201.Anheuser, K. & France, P. Silver plating technology of the late 3rd century Roman coinage. Historical Metallurgy 36(1), 17–23 (2002).Anheuser, K. & Northover, P. Silver plating on Roman and Celtic coins from Britain– A technical study. The British Numismatic Journal 64, 22–32 (1994).Anheuser, K. Where is all the amalgam silvering? Materials Issues1996 in Art and Archaeology - V proceedings, Boston.Beck, L. et al. In NIM 269, 2011 and in Counterfeit coinage of the Holy Roman Empire in the 16th century: silvering process and archaeometallurgical replications, Archaeometallurgy in Europe III.Deraisme, A., Beck, L., Pilon, F. & Barrandon, J. N. A study of the silvering process of the Gallo-Roman coins forged during the third century AD. Archaeometry 48, 469–480 (2006).Giumlia-Mair, A. On surface analysis and archaeometallurgy. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 239, 35–43 (2005).Tate, J. Some problems in analysing museum material by nondestructive surface sensitive techniques. Nuclear Inst. and Methods in Physics Research, B, 14 (1), pp. 20–23 (1986).Beck, L., Bosonnet, S., Réveillon, S., Eliot, D. & Pilon, F. Silver surface enrichment of silver-copper alloys: A limitation for the analysis of ancient silver coins by surface techniques. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 226, 153–162 (2004).Pardini, L. et al. X-ray fluorescence and laser-induced breakdown spectroscopy analysis of Roman silver denarii. Spectrochim. Acta - Part B At. Spectrosc. 74–75, 156–161 (2012).Klockenkämper, R., Bubert, H. & Hasler, K. Detection of near-surface silver enrichment on Roman imperial silver coins by x-ray spectral analysis. Archaeometry 41, 311–320 (1999).Ponting, M., Evans, J. A. & Pashley, V. Fingerprinting of roman mints using laser-amblation MC-ICP-MS lead isotope analysis.Del Hoyo-Meléndez, J. M. et al. Micro-XRF analysis of silver coins from medieval Poland. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 349, 6–16 (2015).Cesare Brandi. Il restauro. Teoria e pratica (1939–1986). (Editori Riuniti, 2009).Barberio, M., Veltri, S., Scisciò, M. & Antici, P. Laser-Accelerated Proton Beams as Diagnostics for Cultural Heritage. Sci. Rep. 7, 40415 (2017).Linke, R., Sehreiner, M., Demortier, G., Alram, M. & Winter, H. Non-Destructive Microanalysis of Cultural Heritage Materials. Comprehensive Analytical Chemistry 42, (Elsevier, 2004).Łojewska, J. et al. Recognizing ancient papyri by a combination of spectroscopic, diffractional and chromatographic analytical tools. Sci. Rep. 7, 46236 (2017).Meulebroeck, W., Wouters, H., Nys, K. & Thienpont, H. Authenticity screening of stained glass windows using optical spectroscopy. Nat. Sci. Reports 6 37726, 1–10 (2016).Martina, I., Wiesinger, R. & Schreiner, M. Micro-Raman Characterisation of Silver Corrosion Products: Instrumental Set Up and Reference. e-Preservation. Sci. Rep 9, 1–8 (2012).Rizzo, F. et al. Non-destructive determination of the silver content in Roman coins (nummi), dated to 308–311 A. D., by the combined use of PIXE-alpha, XRF and DPAA techniques. Microchem. J. 97, 286–290 (2011).Carl, M. & Young, M. L. Complementary analytical methods for analysis of Ag-plated cultural heritage objects. Microchem. J. 126, 307–315 (2016).Cepriá, G., Abadías, O., Pérez-Arantegui, J. & Castillo, J. R. Electrochemical Behavior of Silver-Copper Alloys in Voltammetry of Microparticles: A Simple Method for Screening Purposes. Electroanalysis 13, 477–483 (2001).Capelo, S., Homem, P. M., Cavalheiro, J. & Fonseca, I. T. E. Linear sweep voltammetry: a cheap and powerful technique for the identification of the silver tarnish layer constituents. J. Solid State Electrochem. 17, 223–234 (2013).Doménech-Carbó, A. et al. Detection of archaeological forgeries of Iberian lead plates using nanoelectrochemical techniques. The lot of fake plates from Bugarra (Spain). Forensic Sci. Int. 247, 79–88 (2015).Doménech-Carbó, A., Doménech-Carbó, M. T. & Peiró-Ronda, M. A. ‘One-Touch’ Voltammetry of Microparticles for the Identification of Corrosion Products in Archaeological Lead. Electroanalysis 23, 1391–1400 (2011).Doménech-Carbó, A., Doménech-Carbó, M. T., Montagna, E., Álvarez-Romero, C. & Lee, Y. Electrochemical discrimination of mints: The last Chinese emperors Kuang Hsü and Hsüan T’ung monetary unification. Talanta1 69, 50–56 (2017).Ager, F. J. et al. Combining XRF and GRT for the analysis of ancient silver coins. Microchem. J. 126, 149–154 (2016).Fawcett, T., Blanton, J., Blanton, T., Arias, L. & Suscavage, T. Non-destructive evaluation of Roman coin patinas from the 3rd and 4th century. Powder Diffraction, 1–10.Salvemini, F. et al. Neutron tomographic analysis: Material characterization of silver and electrum coins from the 6th and 5th centuries B.C. Mater. Charact. 118, 175–185 (2016).Ashkenazi, D., Gitler, H., Stern, A. & Tal, O. Metallurgical investigation on fourth century BCE silver jewellery of two hoards from Samaria. Sci. Rep. 7, 40659 (2017).Romano, F. P., Garraffo, S., Pappalardo, L. & Rizzo, F. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques. Spectrochim. Acta - Part B At. Spectrosc. 73, 13–19 (2012).Ingo, G. M. et al. Ancient Mercury-Based Plating Methods: Combined Use of Surface Analytical Techniques for the Study of Manufacturing Process and Degradation Phenomena. Accounts of Chemical Research 46(11), 2365–2375.Pouchou, J. L. & Pichoir, F.¨PAP¨ (ϕ–ρ–Z) procedure for improved quantitative microanalysis, in: Armstrong, J. T. (Ed.), Microbeam Analysis, San Francisco Press, San Francisco, pp. 104–106 (1985)

    An investigation of amalgam gilding and silvering on metalwork

    No full text
    SIGLEAvailable from British Library Document Supply Centre-DSC:D193185 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Staining of archaeological glass from manganese-rich environments

    No full text
    It has been suggested that both internal and external sources of manganese may produce the black or brown staining that often occurs in buried archaeological glass. Modern potash glass of a manganese-free medieval composition was scratched, etched and immersed in an aqueous solution containing dissolved manganese. After several weeks, immersion samples were sectioned and examined by SEM–EDX. Manganese was shown to be present in fissures and cracks within in the glass, where alkali had been depleted. Manganese from an external source is capable of blackening buried medieval potash glass

    Is there still a place for retroperitoneal lymph node dissection in clinical stage 1 nonseminomatous testicular germ-cell tumours? A retrospective clinical study

    No full text
    Abstract Background Primary retroperitoneal lymph node dissection (RPLND) ultimately lost its role as the standard management of clinical stage (CS) 1 nonseminomatous (NS) testicular germ cell tumours (GCTs) in Europe when the European Germ Cell Cancer Consensus Group released their recommendations in 2008. Current guide-lines recommend surgery only for selected patients but reasons for selection remain rather ill-defined. We evaluated the practice patterns of the management of CS1 patients and looked specifically to the role of RPLND among other standard treatment options. Methods We retrospectively evaluated the treatment modalities of 75 consecutive patients treated for CS1 NS at one centre during 2008–2017. The patients undergoing RPLND were selected for a closer review. Particular reasons for surgery, clinical features of patients, and therapeutic outcome were analyzed using descriptive statistical methods. Results Twelve patients (16%) underwent nerve-sparing RPLND, nine surveillance, 54 had various regimens of adjuvant chemotherapy. Particular reasons for surgery involved illnesses precluding chemotherapy (n = 2), patients´ choice (n = 4), and teratomatous histology of the primary associated with equivocal radiologic findings (n = 6). Five patients had lymph node metastases, two received additional chemotherapy. Antegrade ejaculation was preserved in all cases. One patient had a grade 2 complication that was managed conservatively. All RPLND-patients remained disease-free. Conclusions Primary RPLND is a useful option in distinct CS1 patients, notably those with concurrent health problems precluding chemotherapy, and those with high proportions of teratoma in the primary associated with equivocal radiological findings. Informed patient’s preference represents another acceptable reason for the procedure. RPLND properly suits the needs of well-selected patients with CS1 nonseminoma and deserves consideration upon clinical decision-making

    Can germ cell neoplasia in situ be diagnosed by measuring serum levels of microRNA371a-3p?

    No full text
    Purpose: Diagnosing germ cell neoplasia in situ (GCNis) can detect germ cell tumours (GCTs) at the pre-invasive stage. To date, testicular biopsy with the potential of surgical complications is the only way of safely diagnosing GCNis. Recently, microRNAs (miRs) 371-3, and miR 367 were shown to be valuable serum biomarkers of GCTs. We explored the usefulness of these candidate miRs as a marker for GCNis. Methods: 27 patients with GCNis and no concomitant GCT were enrolled. All patients underwent measuring serum levels of miR-371a-3p and miR-367-3p before treatment, 11 had repeat measurement after treatment, 2 also had testicular vein blood examinations. Serum levels were measured by quantitative PCR. In addition, four orchiectomy specimens of patients with GCT were examined immunohistochemically and by in situ hybridization (ISH) with a probe specific for miR-371a-3p to look for the presence of this miR in GCNis cells. Results: The median serum level of miR-371a-3p was significantly higher in patients with GCNis than in controls, miR-367 levels were not elevated. Overall, 14 patients (51.9%) had elevated serum levels of miR-371a-3p. The highest levels were found in patients with bilateral GCNis. Levels in testicular vein serum were elevated in both of the cases. After treatment, all elevated levels dropped to normal. In two orchiectomy specimens, miR-371a-3p was detected by ISH in GCNis cells. Conclusions: Measuring miR-371a-3p serum levels can replace control biopsies after treatment of GCNis. In addition, the test can guide clinical decision making regarding the need of testicular biopsy in cases suspicious of GCNis
    corecore