30 research outputs found
Electrical and non electrical characteristics for the fast detection of high current free-burning arcs
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
[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. 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An investigation of amalgam gilding and silvering on metalwork
SIGLEAvailable from British Library Document Supply Centre-DSC:D193185 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Staining of archaeological glass from manganese-rich environments
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
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
Fehlervermeidung durch strukturiertes Komplikationsmanagement: Quick Reference Cards als Standards zu mehr Effizienz
Can germ cell neoplasia in situ be diagnosed by measuring serum levels of microRNA371a-3p?
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