Astro2020: Empirically Constraining Galaxy Evolution

Over the past decade, empirical constraints on the galaxy-dark matter halo connection have significantly advanced our understanding of galaxy evolution. Past techniques have focused on connections between halo properties and galaxy stellar mass and/or star formation rates. Empirical techniques in the next decade will link halo assembly histories with galaxies' circumgalactic media, supermassive black holes, morphologies, kinematics, sizes, colors, metallicities, and transient rates. Uncovering these links will resolve many critical uncertainties in galaxy formation and will enable much higher-fidelity mock catalogs essential for interpreting observations. Achieving these results will require broader and deeper spectroscopic coverage of galaxies and their circumgalactic media; survey teams will also need to meet several criteria (cross-comparisons, public access, and covariance matrices) to facilitate combining data across different surveys. Acting on these recommendations will continue enabling dramatic progress in both empirical modeling and galaxy evolution for the next decade.Comment: Science white paper submitted to the Astro2020 Decadal Surve

Thermomechanical modeling and brittle interface characterization for on-chip fluidic cooler in microelectronic packages

The overall goal of this work is to develop a reliable microfluidic architecture for high heat-flux microelectronic applications by experimentally characterizing glass-silicon interface. This is achieved through an innovative technique and by employing numerical simulations and analytical models to ensure that the interface will not crack or delaminate under given pressure and temperature conditions. This work also aims to examine microfluidic architectures of different generations and designs to achieve its goal. Thus, the first objective of this work is to perform a thermomechanical analysis of a high-pressure, two-phase microfluidic cooler using numerical models. The next objective is to develop a reliable microfluidic architecture with an appropriate pin-fin configuration. This requires characterizing and understanding the failure modes through analysis of various generations of prototype thermal test vehicles for high-pressure two-phase cooling. These models underscored the significance of understanding the failure mode of the silicon-glass interface and provide context for the third and fourth objectives. The third objective involves analyzing the mechanical behavior of the silicon-glass interface through using pin fin optimization models to design thermal test vehicles as well as experimental pressure test devices. These models and resulting devices work in tandem with the experimental methodology of objective fourth. The fourth and final objective is to develop an innovative experimental test technique for evaluating the mechanical performance of a silicon-glass interface. By using a pressurized cavity to apply load on the silicon-glass interface, this test more accurately mimics the conditions of a high-pressure microfluidic cooler than existing test techniques for evaluating brittle interfaces.Ph.D