The transient response of a millimeter-sized sessile droplet under electrical actuation is experimentally investigated. Under DC actuation, the droplet spreading rate increases as the applied voltage is increased due to the higher electrical forces induced. At sufficiently high DC voltages, competition between the electrical actuation force, droplet inertia, the retarding surface tension force ...

Title of dissertation: CONVERGENCE OF ADAPTIVE FINITE ELEMENT METHODS Khamron Mekchay, Doctor of Philosophy, 2005 Dissertation directed by: Professor Ricardo H. Nochetto Department of Mathematics We develop adaptive finite element methods (AFEMs) for elliptic problems, and prove their convergence, based on ideas introduced by Dörfler [7], and Morin, Nochetto, and Siebert [15, 16]. We first stud...

We demonstrate a monolithic and quasi-phasematched singly resonant cw optical parametric oscillator in periodically poled lithium niobate. The threshold is 1.0 W and the OPO delivers up to 0.98 W signal power tunable between 1750 and 1950 nm (2710 and 2340 nm idler, respectively). We identify cascaded parasitic oscillation effects and analyze their behavior theoretically, showing good agreement...

Nguyen Van Dao is a leading expert in the field of mechanics Vietnam. In this paper, we present some contributions to theory nonlinear oscillation. His outstanding studies are interaction between self-excited, forced and parametric vibrations, equally important there effect dynamic absorbers systems.

The paper is concerned with the stabilization of the nonlinear panel oscillation by an active control. The control is actuated by a combination of additive and parametric vibrational forces. A general method of vibrational control is presented for stabilizing panel vibration satisfying a nonlinear beam equation. To obtain analytical results, a perturbation technique is used in the case of weak ...

We report a continuous-wave (cw) 532-nm-pumped singly resonant optical parametric oscillator (SRO) based on periodically poled lithium niobate. The pump source is a commercial 5-W cw diode-pumped, multilongitudinal-mode, intracavity-doubled Nd:YVO(4) laser. Using a four-mirror ring SRO cavity and single-pass pumping, we achieved subwatt internal oscillation threshold, 56% quantum efficiency, an...

We predict and experimentally observe temporal self-pulsing in singly resonant intracavity second-harmonic generation under conditions of simultaneous parametric oscillation. The threshold for self-pulsing as a function of cavity tuning and phase mismatch are found from analysis of a three-component mean-field model. Analytical mean-field calculations of the self-pulsing frequency as well as nu...

The effects of amplitude modulation of RF cavity voltage on the longitudinal beam dynamics were studied experimentally at SRRC by using a streak camera system. The characteristics of parametric resonance in single bunch beam was investigated both by simulation and measurement. The formation of beamlets in the bunch helps to damp the coherent bunch oscillation. This property is employed to provi...

I numerically model broad-bandwidth optical parametric oscillation and amplification to explore the influence of pump bandwidth on conversion efficiency, injection seeding, and generated spectra. I also study narrowbandwidth pumping of broad-bandwidth signal and idler waves. I show that the relative group velocities of the three waves have a critical effect on device performance in all cases an...

We propose a flexible scheme based on three coupled optical microcavities that permits us to achieve stable oscillations in the microwave range, the frequency of which depends only on the cavity coupling rates. We find that the different dynamical regimes (soft and hard excitation) affect the oscillation intensity, but not their periods. This configuration may permit us to implement compact hyp...