Search results for "Hardness ratio"
showing 3 items of 3 documents
Spatial identification of the overionized plasma in W49B
2010
Recent Suzaku X-ray observations of the ejecta-dominated supernova remnant W49B have shown that in the global spectrum there is a clear indication for the presence of overionized plasma whose physical origin is still under debate. In order to ascertain the physical origin of such a rapidly cooling plasma, we focus on the study of its spatial localization within the X-ray emitting ejecta. We confirm the presence of a saw-edged excess (interpreted as a strong radiative recombination continuum) in the global spectrum above 8 keV, emerging above the ionization-equilibrium model. We produce a hardness ratio map to determine where the plasma is overionized and we perform a spectral analysis of th…
The effect of different insertion techniques on the depth of cure and vickers surface micro-hardness of two bulk-fill resin composite materials
2016
BACKGROUND The aim of this study was to evaluate the Vickers surface micro-hardness and the depth of cure of two bulk-fill resin composites and one incremental-fill resin composite. MATERIAL AND METHODS Two Bulk-fill dental resin composites (X-tra Fil, Voco; Sonic-FillTM 2, Kerr Corporation) and an incremental-fill dental resin composite (Filtek™ Z250 XT, 3M ESPE) were used. Sixty cylindrical specimens of 4 mm thickness were prepared using split Teflon moulds. Specimens were divided into six groups (n=10) according to the type of the material used and according to the insertion technique applied (bulk or incremental). Prepared specimens were stored dry in complete darkness at 37°C for 24 ho…
Minimal exposure time of different LED-curing devices
2007
Abstract Objectives The purpose of the study was to investigate the shortest possible exposure time of different LED-curing devices for five different resin composites in a clinically relevant in vitro-model, where a 7 mm distance from the light guide tip to the bottom side of the cavity was compiled. Methods Resin composite samples (Tetric EvoCeram A3, Filtek Supreme XT A3B, Premise A3, CeramX Mono M5, QuiXfil) were filled in three increments of 2 mm thickness each in stainless steel moulds (O = 5 mm, h = 6 mm, n = 9). The samples were incrementally exposed to different blue LED-curing devices (Bluephase, Bluephase C8, Bluephase 16i/Ivoclar Vivadent, L.E.Demetron II/sds Kerr, Elipar Free…