2,461 research outputs found
An automatically generated high-resolution earthquake catalogue for the 2016-2017 Central Italy seismic sequence, including P and S phase arrival times
No full textCatalog of 440,697 earthquakes of the 2016-2017 Central Italy seismic sequence semi-automatically generated by Spallarossa et al. (2020). The catalogue covers one year of aftershocks following the first mainshock of the sequence (from 08242016 to 08312017).
The catalog has been generated using the Complete Automatic Seismic Processor (CASP) procedure (Scafidi et al., 2019) to detect the events and an advanced picker engine (RSNI-Picker2; Scafidi et al., 2018; Spallarossa et al., 2014) to determine their phase arrival times. The final set of about 7 million P- and 10 million S-wave arrival times have been used to locate the events using a non-linear location algorithm (NonLinLoc; Lomax et al. 2000), with a 1D velocity model calibrated for the area (De Luca et al., 2009) and station corrections. For each event, also local magnitudes (ML) has been calculated as well as a locations quality.
Earthquake locations quality has been classified by means of the procedure proposed by Michele et al., (2019) consisting of the combination of diverse uncertainty parameters provided by the NonLinLoc location code. Locations quality is provided in terms of a unique numeric normalized value, named quality factor, varying between qf=0 (best quality location) and qf=1 (worst quality location). Then locations have been assigned to a quality class depending on the qf parameter value according to the following scheme: A-class (0 < qf ≤ 0.25), B-class (0.25 < qf ≤ 0.50), C-class (0.50 < qf ≤ 0.75), and D-class (0.75 < qf < 1.00). The earthquake locations are distributed between the quality classes as A-30.6%, B-31.4%, C-18.6%, and D-19.4% (details in Spallarossa et al., 2020).
We accompanied the catalogue with the 30 events with M>3.5 missed by our procedure (bring the total number of events to 440,727), including the first Amatrice mainshock (MW6.0; see Spallarossa et al., 2020). These 30 missing events recognisable by the ID starting with ISI), have been taken from INGV bulletin (http://terremoti.ingv.it; ISIDe Working Group., 2007), manually generated. These additional events report INGV locations and magnitude parameters while are missing related quality factors and quality class, being generated by a different procedure.
We added to the larger events, the available moment magnitudes (MW) from Time Domain Moment Tensor catalogue (http://terremoti.ingv.it/tdmt; Scognamiglio et al., 2006).
The catalog is in csv format, semicolon separator, ordered by origin time and the header content is the following:
Id-event – ID
Latitude (°) expressed in decimal degrees - LAT
Longitude (°) expressed in decimal degrees - LON
Depth(km) hypocentral depth expressed in kilometres - DEP
Year of origin time in the format yyyy - YR
Month of origin time in the format mo - MON
Day of origin time in the format dd - DY
Hour of origin time in the format hh - HR
Minute of origin time in the format mi - MIN
Second of origin time in the format XX.XXX s - SEC
Local Magnitude - ML
Standard deviation of the Local Magnitude – STD
Moment Magnitude – Mw (from TDMT)
Horizontal Error (from NLL output) (km) expressed in kilometres - ERH
Vertical Error (from NLL output) (km) expressed in kilometres - ERZ
RMS (from NLL output) (s) expressed in seconds - RMS
Number of Phases – NPHS
Stations Azimuthal GAP (°) expressed in decimal degrees - GAP
Quality factor - Qf
Quality class - Qc
De Luca G., M. Cattaneo, G. Monachesi and A, Amato (2009). Seismicity in the Umbria-Marche region from the integration of national and regional seismic networks. Tectonophysics, 476(1), 219-231. doi: 10.1016/j.tecto.2008.11.032.
ISIDe Working Group. (2007). Italian Seismological Instrumental and Parametric Database (ISIDe). Istituto Nazionale di Geofisica e Vulcanologia (INGV); https://doi.org/10.13127/ISIDE.
Lomax, A., J. Virieux, P. Volant, and C. Berge-Thierry (2000). Probabilistic earthquake location in 3D and layered models: introduction of a Metropolis–Gibbs method and comparison with linear locations. In: Advances in seismic event location, ed. C. H. Thurber and N. Rabinowitz, 101–134. Dordrecht and Boston: Kluwer Academic Publishers.
Michele, M., Latorre, D., Emolo, A. (2019). An Empirical Formula to Classify the Quality of Earthquake Locations. Bulletin of the Seismological Society of America. Vol. 109, No. 6, pp. 2755–2761, December 2019, doi: 10.1785/0120190144.
Scafidi, D., Viganò A., Ferretti G., and Spallarossa D. (2018). Robust picking and accurate location with RSNI-Picker2: real-time automatic monitoring of earthquakes and non-tectonic events, Seismol. Res. Lett, Vol. 89 (4), pp. 1478-1487, doi: 10.1785/0220170206.
Scafidi D, Spallarossa D, Ferretti G, Barani S, Castello B, Margheriti L (2019). A complete automatic procedure to compile reliable seismic catalogs and travel-time and strong-motion parameters datasets. Seismol Res Lett 90(3):1308–1317.
Scognamiglio, L., Tinti, E., Quintiliani, M. (2006). Time Domain Moment Tensor [Data set]. Istituto Nazionale di Geofisica e Vulcanologia (INGV). https://doi.org/10.13127/TDMT.
Spallarossa, D., G. Ferretti, D. Scafidi, C. Turino, and M. Pasta (2014). Performance of the RSNI-Picker, Seismol. Res. Lett. 85, 1243–1254.
Spallarossa D., Cattaneo M., Scafidi D., Michele M., Chiaraluce L., Segou M. and I. G. Main (2020). An automatically generated high-resolution earthquake catalogue for the 2016-2017 Central Italy seismic sequence, including P and S phase arrival times. Geophys. J. Int. doi: 10.1093/gji/ggaa604
Una nuova procedura per il calcolo delle tensioni residue con il metodo della rosetta forata basata sulla tecnica di Newton-Raphson
No full textThe hole drilling method is one of the most used semi-destructive techniques for residual
stress analysis in mechanical parts. In the presence of non-uniform residual stress, the stress
field can be determined from the measured relaxed strains using several methods, but the
most used one is the so called integral method. This method is characterised by some
simplifications that lead to approximate results especially when the residual stress varies
abruptly. In this paper a new calculation procedure based on the Newton-Raphson method
for the determination of zeroes of functions is presented. The advantages of the method are
also explained and validated by the application to simulated stress fields
Una procedura generale per la valutazione delle tensioni residue con il metodo del foro
No full textIl metodo della rosetta forata è una delle più note tecniche semidistruttive di analisi delle tensioni residue su componenti meccanici. In presenza di tensioni non uniformi, il campo delle tensioni può essere determinato a partire dalle deformazioni rilassate utilizzando varie procedure di calcolo basate sulla stessa equazione, chiamata equazione integrale. In questo lavoro viene presentata una nuova procedura di calcolo basata sul metodo di Newton-Raphson per la determinazione degli zeri di una funzione. La tecnica proposta presenta due importanti vantaggi rispetto alle altre tecniche: 1) è basata su una teoria piuttosto generale che permette di ottenere le principali tecniche esistenti come casi particolari, 2) permette di usare funzioni di tensione più complesse ed efficaci per la risoluzione del problema in un modo piuttosto semplice
A NEW PROCEDURE FOR THE EVALUATION OF RESIDUAL STRESSES BY THE HOLE DRILLING METHOD BASED ON NEWTON-RAPHSON TECHNIQUE
No full textIn this paper the combined use of both RGB and phase stepping photoelasticity is
proposed. The method is characterised by the following features: maximum measurable order greater than that of the RGB method, ability to determine the total fringe order without necessity of unwrapping
B-Scan image analysis for position and shape defect definition in plates
No full textDefinition of size, shape and location of defects into a mechanical component is of extreme importance in the manufacturing industry in general and particularly in high-tech applications, and in applications that can become dangerous due to the structural failure of mechanical components. In this paper, a laser-UT system has been used to define position and shape of internal defects in aluminum plates. An infrared pulsed laser is used to generate ultrasonic waves in a point of the plate and a CW laser interferometer is used as receiver to acquire the out-of-plane displacements due to the ultrasonic waves in another point of the plate. The method consists of acquiring a B-Scan map on which some information on the defects in the mechanical component are visible. Storing the characteristics of the wave reflected by the defect and acquired in the B-Scan, the detection and the drawing of the defect is possible. The acquisition of the times of arrival of the waves reflected by the defect from the B-scan allows defining large parts of the shape of the defect. The times of arrival are acquired from the B-scan by analyzing the colour variations due to the wave reflected by the defect. The experiments operated from both sides of the plate allow drawing the defect in a virtual image of the plate section, from which the definition of defect shape and position can be determined
A New Procedure for the Evaluation of Non-Uniform Residual Stresses by the Hole Drilling Method Based on the Newton-Raphson Technique
No full textThe hole drilling method is one of the most used semi-destructive techniques for the analysis of residual stresses in mechanical components. The non-uniform stresses are evaluated by solving an integral equation in which the strains relieved by drilling a hole are introduced. In this paper a new calculation procedure, based on the Newton-Raphson method for the determination of zeroes of functions, is presented. This technique allows the user to introduce complex and effective forms of stress functions for the solution of the problem. All the relationships needed for the evaluation of the stresses are obtained in explicit form, eliminating the need to use additional mathematical tools. The technique is based on a rather general theory that allows to obtain the formulations of various existing techniques as particular cases
Michele Taruffo: el magisterio y la obra ejemplares del genial procesalista «todoterreno»
No full textThe author reflects on Michele Taruffo’s extraordinarily important contribution to the renewal of both conventional procedural law scholarship and the theoretical background of law-court professionals. Taruffo’s contribution was achieved by means of introducing to mainstream culture in those circles the necessary knowledge of the underlying epistemic dimension, which was traditionally suppressed by the strictly legal one.El autor discurre acerca de la importantísima contribución de Michele Taruffo a la renovación del procesalismo convencional y del bagaje teórico de los profesionales de la jurisdicción, mediante la incorporación a la cultura dominante en tales medios del imprescindible conocimiento de la dimensión epistémica subyacente y tradicionalmente sofocada por la propiamente jurídica
ANALISI DELLE TENSIONI RESIDUE NEI VETRI MEDIANTE FOTOELASTICITÀ RGB E LASTRA A TINTA SENSIBILE
No full textL'analisi delle tensioni residue nel vetro viene solitamente effettuata mediante metodi fotoelastici. Questo lavoro considera l'automazione del metodo fotoelastico in luce bianca basato sull'uso congiunto della fotoelasticità RGB e di una lastra a tinta sensibile (full wave plate o tint plate), che
manifesta il ritardo di un ordine di frangia, posta in serie alla lastra di vetro. Il metodo proposto è stato applicato all’analisi delle tensioni residue membranali in un vetro temperato
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