We examine different approaches to model viscoelasticity within atomic force microscopy (AFM) simulation. Our study ranges from very simple linear spring-dashpot models to more sophisticated nonlinear systems that are able to reproduce fundamental properties of viscoelastic surfaces, including creep, stress relaxation and the presence of multiple relaxation times. Some of the models examined ha...

This article discusses how several diagnostic tools used by audiologists inter-relate to anatomical abnormalities viewed by video otoscopy. Background of common middle ear pathology is reviewed, with emphasis on new research findings regarding pathophysiology. A review of video otoscopy, multifrequency tympanometry, and otoreflectance is provided. Case studies illustrate the integrated use of t...

We report preliminary results of a 3-year multifrequency polarization campaign of 15 AGNs of blazar type, including bimonthly total and polarized intensity imaging at 7 mm with the VLBA. We find that the sources have two different dependences of degree of polarization on wavelength: sub-mm peaked or straight “polarization spectra”. The fractional polarization of the latter group increases with ...

Introduction: Magnetic Resonance Elastography (MRE) is capable to measure the mechanical properties of living tissue by externally introduced shear vibrations and phase contrast MRI [1]. In multifrequency MRE the complex shear modulus G*(ω) of biological tissue is measured at various mechanical vibration frequencies simultaneously. Viscoelastic tissue parameters can then be calculated by fittin...

We report on the modeling of transient stimulated rotational Raman scattering in H(2) gas. We predict a multifrequency output, spanning a bandwidth greater than the pump frequency, that may be generated without any significant delay with respect to the pump pulses. The roles of dispersion and transiency are quantified.

Recent testing of high-speed cavitating turbopump inducers has revealed the existence of more complex instabilities than the previously recognized cavitating surge and rotating cavitation. This paper explores one such instability that is uncovered by considering the effect of a downstream asymmetry, such as a volute on a rotating disturbance similar to (but not identical to) that which occurs i...