Engineering Commons^™

The Mitigation Of Eutrophication Using Microporous Polymer Membranes To Control Algae Growth, Christopher R. Riley

Materials Engineering

A system was designed to mitigate the accelerated process of anthropogenic eutrophication. This system aimed to contain Chlorella Vulgaris microalgae cells within an enclosed polymer membrane pouch while allowing for water and nutrients to diffuse through the pouch. As a test model, a 10 gallon aquarium was partitioned into three sections using polycarbonate membranes with 1 micron pore diameters. Each section was then gradually filled with a deionized water and Bristol solution recommended for microalgae growth. Phosphate and nitrate were added to Section A of the aquarium and allowed to diffuse throughout the tank. A water pump was used to …

Characterization Of Mixing In A T-Style Microfluidic Chip, Brian Eric Harley

Master's Theses

The goal of this study is to characterize the mixing that occurs in a microfluidic chip. To characterize the mixing, the minimum length to complete mixing and evolution of mixing will be investigated. There are two types of mixing that occur within a microfluidic channel, diffusion and advection. In the beginning of the microfluidic chip, diffusion is the dominant form of mixing, and in the later portion of the microfluidic chip advection is the dominant form of mixing. The type of design used for this experiment was a zig zag geometry microfluidic chip with channel dimensions of 60 µm X …

Diffusion And Reaction In Selected Uranium Alloy System, Ke Huang

Electronic Theses and Dissertations

U-Mo metallic fuels with Al alloys as the matrix/cladding are being developed as low enriched uranium fuels under the Reduced Enrichment for Research and Test Reactor (RERTR) program. Significant interactions have been observed to occur between the U-Mo fuel and the Al alloy during fuel processing and irradiation. U-Zr metallic fuels with stainless steel claddings have been developed for the generation IV sodium fast reactor (SFR). The fuel cladding chemical interaction (FCCI) induced by the interdiffusion of components was also observed. These interactions induce deleterious effects on the fuel system, such as thinning of the cladding layer, formation of phases …

Understanding Degradation And Lithium Diffusion In Lithium Ion Battery Electrodes, Juchuan Li

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries with higher capacity and longer cycle life than that available today are required as secondary energy sources for a wide range of emerging applications. In particular, the cycling performance of several candidate materials for lithium-ion battery electrodes is insufficient because of the fast capacity fading and short cycle life, which is mainly a result of mechanical degradation.

This dissertation mainly focuses on the issue of mechanical degradation in advanced lithium-ion battery electrodes. Thin films of tin electrodes were studied where we observed whisker growth as a result of electrochemical cycling. These whiskers bring safety concerns because they may …