Brad A. Miller

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Hollow hydroxyapatite (HA) microspheres (diameter = 100-800 microm) were prepared by reacting solid Li(2)O-CaO-B(2)O(3) glass spheres in 0.25 M K(2)HPO(4) solution at 37 degrees C. The influence of subsequent heating on the microstructure, surface area, and compressive strength of the HA microspheres was evaluated using scanning electron microscopy, the BET(More)
An Extended Kalman Filter is developed to estimate the linearized direct and indirect stiffness and damping force coefficients for bearings in rotor–dynamic applications from noisy measurements of the shaft displacement in response to imbalance and impact excitation. The bearing properties are modeled as stochastic random variables using a Gauss-Markov(More)
The p-mode oscillations of the Sun are manifestations of resonantly trapped acoustic waves propagating within its interior. The eeective size of the resulting resonant cavity changes with the properties of the modes { the interaction of this phenomenon with a highly localized excitation source in the upper layers of the convection zone gives rise to(More)
Accurate testing of the visual field of aphakic patients is demanding due to the optical distortion induced by high plus corrective lenses. This testing procedure can be improved by using an aspheric contact lens instead of a full-aperture loose trial lens. We found that the contact lens enhances the ability of the pattern-deviation printout of the Statpac(More)
We present a comprehensive frequency analysis of Doppler velocity observations of the visible solar disc made by the Birmingham Solar-Oscillations Network (BiSON) from 1990 { 1996, i.e., covering the falling phase of activity cycle 22, up to and including the cycle 22/23 boundary. We have tted low-degree (low-`) solar p-modes in a variety of power spectra(More)
Variations in the excitation and damping of low-l solar p modes over the solar activity cycle ? ABSTRACT We have searched helioseismic data collected by the Birmingham Solar-Oscillations Network (BiSON) for solar-cycle changes to those low-l p-mode parameters that relate to the excitation and damping of the resonances. These data { collected between 1991(More)
We present measurements of low-degree solar p-mode linewidths, velocity powers, energies and energy supply rates between 1600 Hz and 4700 Hz, as derived from the analysis of several years of high-quality helioseismological data collected by the Birmingham Solar-Oscillations Network (BiSON). For the radial (` = 0) modes, we nd that the total energy E per(More)
We present a detailed study of variations observed in low-angular degree solar p-mode frequencies during solar cycles 22 and 23, and their relation to global and spatially decomposed proxies of the surface activity. To do so, we have analysed 11 yr of unresolved (Sun-as-a-star) Doppler velocity observations of the solar disc made by the Birmingham(More)
We present a list of “best possible” estimates of low-degree p-mode frequencies, from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this purpose, giving exquisite precision in the estimated frequencies. Every effort has been made in the analysis to ensure(More)