124 resultados para Plaque de force
Resumo:
The palatal radicular groove is a morphological tooth defect, which act as local predisposing risk factor favoring accumulation of the bacterial plaque, permitting microbial invasion via root groove way, directly into periodontal structures. A patient diagnosed with palatal radicular groove and a localized periodontal disease was treated by procedures to control bacterial action and procedures to eliminate local predisposing risk factor. To treat the periodontal bone defect a sequelae of periodontal disease, a guided tissue regeneration technique was applied by using allograft and xenograft materials associated with a resorbable demineralized bovine cortical bone membrane. The objective of surgical regenerative procedure was to recover the periodontal tissues nearly as they were before periodontal disease destruction.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
The Frequency Modulated - Atomic Force Microscope (FM-AFM) is apowerful tool to perform surface investigation with true atomic resolution. The controlsystem of the FM-AFM must keep constant both the frequency and amplitude ofoscillation of the microcantilever during the scanning process of the sample. However,tip and sample interaction forces cause modulations in the microcantilever motion.A Phase-Locked Loop (PLL) is used as a demodulator and to generate feedback signalto the FM-AFM control system. The PLL performance is vital to the FM-AFMperformace since the image information is in the modulated microcantilever motion.Nevertheless, little attention is drawn to PLL performance in the FM-AFM literature.Here, the FM-AFM control system is simulated, comparing the performancefor di erent PLL designs.
Resumo:
During the last 30 years the Atomic Force Microscopy became the most powerful tool for surface probing in atomic scale. The Tapping-Mode Atomic Force Microscope is used to generate high quality accurate images of the samples surface. However, in this mode of operation the microcantilever frequently presents chaotic motion due to the nonlinear characteristics of the tip-sample forces interactions, degrading the image quality. This kind of irregular motion must be avoided by the control system. In this work, the tip-sample interaction is modelled considering the Lennard-Jones potentials and the two-term Galerkin aproximation. Additionally, the State Dependent Ricatti Equation and Time-Delayed Feedback Control techniques are used in order to force the Tapping-Mode Atomic Force Microscope system motion to a periodic orbit, preventing the microcantilever chaotic motion