Search results for "deformation"
showing 10 items of 515 documents
Microbial Leakage at the Implant-Abutment Connection Due to Implant Insertion Maneuvers: Cross-Sectional Study 5 Years Postloading in Healthy Patient…
2015
The aim of this study was to test if stress on the prosthetic connection during insertion maneuvers can induce micro-warping at the implant connection. From September 2011 to July 2013, patients with implants loaded for at least 5 years that were placed with 2 different insertion implant mounters—MP (conventional) and ME (mountless)—were selected from all of those who had received dental implant therapy in the past and were attending routine check-up or spontaneous visits during the study period. Samples were obtained from inside the connection and the abutment surface using absorbent sterile paper tips. Quantitative real-time polymerase chain reaction was performed for total bacterial coun…
The contribution of the pre-existing structures in mountain belt evolution: the example of the negative inversion in the Northen Sicily
2004
Syn-orogenic extension has been recognised in Northern Sicily. Mesoscopic analysis has been carried out in three key areas, where folded-and-thrust Mesozoic-to-Tertiary rocks crop-out. The three examples are inherent to Portions Of tectonic Units Which occupy progressively more internal positions in the Sicilian chain from west to east. The extensional deformation is mainly represented by low-angle normal faults and shear bands. A common kinematic process seems to affect the other sector of the chain during the extension and is represented by a generalized negative inversion of previous layer-parallel shear bands and detachments related to the thrusting. The extensional deformation occurred…
A spectroscopic study of low-lying states in neutron-deficient astatine and francium nuclei
2013
Fracture and fatigue of titanium narrow dental implants: New trends in order to improve the mechanical response
2019
Sixty-four fractured commercially pure titanium (cp-Ti) narrow dental implants (NDIs) with similar macrogeometry and connection designs were studied after different implantation times in humans in order to determine their reliability and to evaluate the causes of the fracture. These NDIs were compared with other similar implants, made with alloyed titanium with 15% Zr and with 12% strained titanium. Original implants were tested under static and fatigue conditions, simulating the tri-axial loads in the mouth by means of a Bionix hydraulic test machine. Fractography was studied using field-emission scanning electron microscopy (FSEM). The results showed that cp-Ti NDI exhibits low strength f…
Characterization of thin plastic foils for applications in X-ray optics technology
2007
Thin plastic foils are being investigated to build shell optics for X-ray telescopes. Compared to polished glass optics, the advantage is in terms of increased collecting area, light weight and lower cost. Plastic material is also desirable to allow deformation into a complete surface of revolution. We collected plastic materials of common use for industrial applications and also specialty materials developed for the electronic industry. A comparative study was then performed to evaluate the optical quality of the selected plastic films. Surface analysis was carried out with topographic instruments to investigate the microroughness of our samples at different scan lengths. Preliminary resul…
MECCANISMI DI DEFORMAZIONE IN ROCCE CARBONATICHE STRATIFICATE: IMPLICAZIONI PER LA CIRCOLAZIONE DEI GEOFLUIDI
2014
Nel presente lavoro è stata condotta un’analisi quali/quantitativa degli elementi strutturali che caratterizzano alcuni affioramenti carbonatici presenti nella zona di catena esterna della Sicilia occidentale (Monte Maranfusa e Montangna Grande), e nella zona di avampaese in Sicilia sud-orientale (Monti Iblei). Le proprietà petrofisiche delle rocce carbonatiche (porosità, permeabilità), sono strettamente legate all’evoluzione diagenetica di quest’ultime e cambiano in funzione della natura, dell’organizzazione e della forma degli elementi che le costituiscono (grani, pori, cemento, minerali, ecc.). Tali proprietà sono inoltre fortemente condizionate dalla natura delle discontinuità tettonich…
A method for measuring wetting and swelling of bentonite using X-ray imaging
2022
A non-invasive method based on X-ray imaging for measuring deformation and water transport in wetting and swelling bentonite samples is introduced. Sequential X-ray images taken of the samples were used to calculate the attenuation coefficient and deformation. These results, together with careful calibration, allowed finding the dry density and water content distributions and their temporal evolution in the wetting and swelling samples. A specific correction technique, based on regularly taking reference X-ray images of aluminum plates of varying thickness, was developed and used to take into account X-ray beam instabilities and thus to improve the accuracy of density analysis. Large deform…
Stress sensitivity of stylolite morphology
2009
International audience; Stylolites are rough surfaces that form by localized stress-induced dissolution. Using a set of limestone rock samples collected at different depths from a vertical section in Cirque de Navacelles (France), we study the influence of the lithostatic stress on the stylolites morphology on the basis of a recent morphogenesis model. We measured the roughness of a series of bedding-parallel stylolites and show that their morphology exhibits a scaling invariance with two self-affine scaling regimes separated by a crossover-length (L) at the millimeter scale consistent with previous studies. The importance of the present contribution is to estimate the stylolite formation s…
Spectroscopy of short-lived radioactive molecules
2020
Molecular spectroscopy offers opportunities for the exploration of the fundamental laws of nature and the search for new particle physics beyond the standard model1–4. Radioactive molecules—in which one or more of the atoms possesses a radioactive nucleus—can contain heavy and deformed nuclei, offering high sensitivity for investigating parity- and time-reversal-violation effects5,6. Radium monofluoride, RaF, is of particular interest because it is predicted to have an electronic structure appropriate for laser cooling6, thus paving the way for its use in high-precision spectroscopic studies. Furthermore, the effects of symmetry-violating nuclear moments are strongly enhanced5,7–9 in molecu…
Scattering of Co-Current Surface Waves on an Analogue Black Hole
2018
We report on what is to our knowledge the first scattering experiment of surface waves on an accelerating transcritical flow, which in the analogue gravity context is described by an effective spacetime with a black-hole horizon. This spacetime has been probed by an incident co-current wave, which partially scatters into an outgoing countercurrent wave on each side of the horizon. The measured scattering amplitudes are compatible with the predictions of the hydrodynamical theory, where the kinematical description in terms of the effective metric is exact.