18,398 research outputs found
Piezoelectric/Triboelectric Nanogenerators for Biomedical Applications
Bodily movements can be used to harvest electrical energy via nanogenerators and thereby enable self-powered healthcare devices. In this chapter, first we summarize the requirements of nanogenerators for the applications in biomedical fields. Then, the current applications of nanogenerators in the biomedical field are introduced, including self-powered sensors for monitoring body activities; pacemakers; cochlear implants; stimulators for cells, tissues, and the brain; and degradable electronics. Remaining challenges to be solved in this field and future development directions are then discussed, such as increasing output performance, further miniaturization, encapsulation, and improving stability. Finally, future outlooks for nanogenerators in healthcare electronics are reviewed
Algebraic Bethe ansatz for the elliptic quantum group and its applications
We study the tensor product of the {\it higher spin representations} (see the
definition in Sect. 2.2) of the elliptic quantum group .
The transfer matrices associated with the -module are
exactly diagonalized by the nested Bethe ansatz method. Some special cases of
the construction give the exact solution for the Belavin model and for
the elliptic Ruijsenaars-Schneider model.Comment: 23 pages, latex file, to appear in Nucl. Phys.
An Explicit Scheme for Incorporating Ambipolar Diffusion in a Magnetohydrodynamics Code
We describe a method for incorporating ambipolar diffusion in the strong
coupling approximation into a multidimensional magnetohydrodynamics code based
on the total variation diminishing scheme. Contributions from ambipolar
diffusion terms are included by explicit finite difference operators in a fully
unsplit way, maintaining second order accuracy. The divergence-free condition
of magnetic fields is exactly ensured at all times by a flux-interpolated
constrained transport scheme. The super time stepping method is used to
accelerate the timestep in high resolution calculations and/or in strong
ambipolar diffusion. We perform two test problems, the steady-state oblique
C-type shocks and the decay of Alfv\'en waves, confirming the accuracy and
robustness of our numerical approach. Results from the simulations of the
compressible MHD turbulence with ambipolar diffusion show the flexibility of
our method as well as its ability to follow complex MHD flows in the presence
of ambipolar diffusion. These simulations show that the dissipation rate of MHD
turbulence is strongly affected by the strength of ambipolar diffusion.Comment: 25 pages, 5 figures, ApJS accepte
Graphene Oxidation: Thickness Dependent Etching and Strong Chemical Doping
Patterned graphene shows substantial potential for applications in future
molecular-scale integrated electronics. Environmental effects are a critical
issue in a single layer material where every atom is on the surface. Especially
intriguing is the variety of rich chemical interactions shown by molecular
oxygen with aromatic molecules. We find that O2 etching kinetics vary strongly
with the number of graphene layers in the sample. Three-layer-thick samples
show etching similar to bulk natural graphite. Single-layer graphene reacts
faster and shows random etch pits in contrast to natural graphite where
nucleation occurs at point defects. In addition, basal plane oxygen species
strongly hole dope graphene, with a Fermi level shift of ~0.5 eV. These oxygen
species partially desorb in an Ar gas flow, or under irradiation by far UV
light, and readsorb again in an O2 atmosphere at room temperature. This
strongly doped graphene is very different than graphene oxide made by mineral
acid attack.Comment: 15 pages, 5 figure
Piezoelectric Materials for Medical Applications
This chapter describes the history and development strategy of piezoelectric materials for medical applications. It covers the piezoelectric properties of materials found inside the human body including blood vessels, skin, and bones as well as how the piezoelectricity innate in those materials aids in disease treatment. It also covers piezoelectric materials and their use in medical implants by explaining how piezoelectric materials can be used as sensors and can emulate natural materials. Finally, the possibility of using piezoelectric materials to design medical equipment and how current models can be improved by further research is explored. This review is intended to provide greater understanding of how important piezoelectricity is to the medical industry by describing the challenges and opportunities regarding its future development
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