RESUMEN
The precise value of the g factor in graphene is of fundamental interest for all spin-related properties and their application. We investigate monolayer graphene on a Si/SiO_{2} substrate by resistively detected electron spin resonance. Surprisingly, the magnetic moment and corresponding g factor of 1.952±0.002 is insensitive to charge carrier type, concentration, and mobility.
Asunto(s)
Grafito , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Prótesis Valvulares Cardíacas , Falla de Prótesis , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/uso terapéutico , Grafito/química , Grafito/uso terapéutico , Humanos , Ensayo de Materiales/métodos , Diseño de PrótesisRESUMEN
Graphene plasmons promise unique possibilities for controlling light in nanoscale devices and for merging optics with electronics. We developed a versatile platform technology based on resonant optical antennas and conductivity patterns for launching and control of propagating graphene plasmons, an essential step for the development of graphene plasmonic circuits. We launched and focused infrared graphene plasmons with geometrically tailored antennas and observed how they refracted when passing through a two-dimensional conductivity pattern, here a prism-shaped bilayer. To that end, we directly mapped the graphene plasmon wavefronts by means of an imaging method that will be useful in testing future design concepts for nanoscale graphene plasmonic circuits and devices.
RESUMEN
As surface roughness may play a role in the mechanical attachment of an implant surface to bone, various implant surfaces have been prepared and analyzed by removal torque (countertorque) or push-out tests in a variety of animal model systems. Rougher surfaces generally have displayed higher mechanical testing values, indicating a stronger implant-bone interface. This pilot study was undertaken to test the countertorque values for integrated threaded implants with surfaces prepared by machining, blasting, and acid-etching, to compare the various implant surface types histomorphometrically for percentage of bone-implant contact under loaded and unloaded conditions, and to determine the degree of correlation between countertorque values and bone-implant contact with varying degrees of surface roughness. The results of this animal investigation suggest that the strength of the bone-implant interface, as determined by countertorque testing, is influenced by different surface characteristics. Acid-etched surfaces resisted countertorque forces more successfully as compared with blasted or machined surfaces. Histologic evaluation of bone contact with the various implant surfaces did not demonstrate a definite advantage for rougher surfaces in regard to percentage of bone contact at the light microscopic level.