Margaret Stern

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In northwestern Costa Rica, cattle are being used as a "management tool" to reduce the amount of combustible material, mainly dominated by Hyparrhenia rufa, an African grass. This project is being developed within Parque Nacional Palo Verde and Reserva Biológica Lomas Barbudal, both of which form part of the only remaining tropical dry forests in(More)
The capability and diversity of high performance microprocessors is increasing with each process technology generation in order to meet increasing application demand. The cooling designs for these electronic chips have to deal with larger temperature gradients across the die than previously. The key to thermal management is to dissipate the thermal energy(More)
We use quantum mechanical analogy to introduce a new class of optical resonators with finite deflection profile mirrors that support a finite number of discrete confined transverse modes and a continuum of unconfined transverse modes. We develop theory of such resonators, experimentally demonstrate micro-optical resonators intrinsically confining only a(More)
An approach for synthesizing microand nano-sized gold wires by infiltration and thermolysis is investigated. A porous ZrO2 ceramic preform with aligned pores obtained by unidirectional freezing and freeze-drying is employed as an infiltration template. The sintered porous ZrO2 preform is then infiltrated by a brushing gold solution. The thermolysis is(More)
Future high performance systems may incorporate liquid cooling to the board. These systems will be assembled using commercially available components and subsystems, which include the pump, liquid coolant, tubing and connections, heat exchanger, and cold plate. Liquid cooling systems are known to be susceptible to more degradation and failure mechanisms than(More)
We describe the preliminary design, fabrication, and demonstration of an array of micro-optics that is used to separate colors locally on the focal plane. The 64 x 64 array combines 100 microm x 100 microm, F/2 refractive microlenses with a 17-microm period grating. The microlenses concentrate the incoming radiation, while the grating disperses the(More)
We present a theoretical model and its experimental verification for speckle-induced noise in laser-based bar-code-scanner systems. We measured the dependence of the signal-to-speckle-noise ratio on distance, spot size, and detector size. Analyses of the power spectra of both the speckle noise and of the measured surface profiles of different substrates(More)