Search results for "penetration"
showing 10 items of 168 documents
Electromagnetic behaviour of superconductive amorphous metals
2005
The penetration depth of the magnetic field into an amorphous superconductor is calculated. The ratio of the London penetration depth δL to the electron free path le under zero temperature is above unity for almost all amorphous metals. That is why pure metals, in a superconducting state, change from type I superconductors to type II superconductors during the crystalline–amorphous transition.
Thermoplastic Properties of Endodontic Gutta-percha: A Thermographic In Vitro Study
2014
Abstract Introduction Endodontic gutta-percha undergoes deformation at temperatures above 65°C. The temperature influence of heat carriers on gutta-percha cones was investigated in vitro. Methods Six single-rooted extracted teeth were embedded in resin and fixed. The root canals were prepared (ProFile; Dentsply Maillefer, Ballaiques, Switzerland) to different tapers and bisected. Thermographic images when heating the gutta-percha cones (Roeko, Langenau, Germany) with a heat carrier (ML .12; SybronEndo, Orange, CA) at 1 and 5 mm from the working length were made with an infrared thermal imaging camera (ThermaCam P640; Flir Systems, Taby, Sweden). The device temperature was preset at 200°C. T…
A penetration depth study on the non-centrosymmetric superconductors Li2(Pd1−xPtx)3B
2008
Abstract We study the superconducting order parameter in the non-centrosymmetric compounds Li 2 (Pd 1− x Pt x ) 3 B ( x =0, 0.3, 0.7 and 1) by measuring magnetic penetration depth λ ( T ). The low temperature λ ( T ) shows a linear temperature dependence for x ⩾0.3, but follows exponential-like behavior for lower Pt contents. These findings suggest that a spin-triplet state might gradually develop with increasing x due to the broken inversion symmetry.
An in vitro evaluation of two dentine adhesive systems to seal the pulp chamber using a glucose penetration model
2010
Objectives: To evaluate the sealing capability of Cavit TM G with or without Clearfil TM S3 Bond and Prime & Bond NT placed in the pulp chamber. Study Design: Forty single rooted premolars, extracted for orthodontic and periodontal reasons, with intact coronal surface and mature apices, were standardized to a length of 15 mm. The teeth were instrumented, filled with a gutta-percha master cone and divided into three groups to obturate the pulp chambers: Cavit TM G; Clearfil TM S3 Bond plus Cavit TM G and Prime & Bond® NT plus Cavit TM G. A glucose leakage model was used for evaluating the coronal microleakage. The Mann-Whitney test was used to evaluate the differences in the means of the glu…
Droplet cell investigation of intergranular corrosion on AA2024
2017
An original method combining a droplet cell with direct optical interrogation of the reverse side of a 50μm thick foil AA2024 has been tested to evaluate the possible analysis of the current during intergranular corrosion tests. The foil microstructure and the selected orientation were suitable for recording the current generated during the propagation in volume of a well-defined grain boundary trace. Even if it is impossible to reach a charge and mass balance from these preliminary attempts, it was demonstrated that it is possible, despite hydrogen evolution, to record a current transient resulting from the full penetration of an intergranular path. Keywords: Intergranular corrosion, Alumi…
Disorder-induced Raman scattering in rhenium trioxide (ReO3)
2007
Raman scattering in cubic metallic perovskite (ReO3) was studied at room temperature for well-crystallized monolith, polycrystalline powder and thin film samples. Defect-induced first-order Raman scattering was detected from the sub-surface region, given by the penetration depth of a 633 nm laser, and its origin was explained on the basis of a rigid-ion vibrational model for bulk ReO3. A quenching of the Raman intensity was observed in crystalline monolithic ReO3 upon increasing the temperature up to 250 °C and was related to crystal surface reconstruction/annealing.
Effect of the several epoxy resin-based sealer compositions on adhesion interface in radicular dentin after calcium hydroxide intracanal medication r…
2021
Made available in DSpace on 2022-04-29T08:32:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Background: This study evaluated the effects of several epoxy resin-based sealer compositions (AHP, AH Plus; ADS, Adseal; SPL, Sealer Plus) on bond strength and intratubular dentin penetration of the endodontic obturation, in root canal previously treated with calcium hydroxide intracanal medication (CH) and removed by continuous ultrasonic irrigation (CUI). Material and Methods: Forty-five maxillary canines were prepared up to F5 (ProTaper system), filled with CH, coronally sealed, and stored at 37ºC. After 1 week, CH was removed using 2.5% sodium hypochlorite energized by CUI. The …
Intensity and persistence of water repellency at different soil moisture contents and depths after a forest wildfire
2022
Abstract The Mediterranean mixed coniferous and broad-leaved forest of Moarda (Palermo) was affected by a large wildfire in summer 2020. In spring 2021, burned and unburned loam soil sites were sampled and the water drop penetration time (WDPT) and ethanol percentage (EP) tests applied to assess the influence of wetting-drying processes and soil water content on post-fire soil water repellency (SWR) as well as its vertical distribution. According to the WDPT test, the surface layer of the natural unburned soils was severely hydrophobic at intermediate soil water contents roughly corresponding to wilting point and SWR reduced either for very dry conditions (air- or oven-dried conditions) or …
Generation and excitation of point defects in silica by synchrotron radiation above the absorption edge
2010
We report photoluminescence measurements carried out on amorphous SiO{sub 2} upon excitation by synchrotron light. Exposure of the as-grown material to above-edge light at low temperature induces the formation of nonbridging oxygen hole centers (NBOHC), localized in a thin layer below the surface limited by the penetration depth (tens of nm) of impinging light. After concluding the exposure to 11 eV light, stable defects are revealed by observing their characteristic 1.9 eV photoemission band excited at 4. 8eV. The local concentration of induced defects, supposedly formed by nonradiative decay of excitons, is very high (close to approx10{sup 21} cm{sup -3}) and independent of the previous h…
A comparative study of the sealing ability of two root canal obturation techniques
1995
A comparison was made of the ability of two root canal obturating techniques to prevent dye microleakage: gutta-percha lateral condensation and mechanically plasticized gutta-percha (JS Quick-fill). Twenty central incisors were prepared and obturated by each technique. After rendering the teeth transparent, linear dye penetration was found to be 0.48 and 0.52 mm, respectively. The difference between the two techniques was not significant. As for the distribution of the sealing cement (AH26) in the teeth obturated with JS Quickfill, the cement was located in the most peripheral zone of the obturation alongside the dentinal walls, whereas the gutta-percha was found in the central part of the …