Mechanical Engineering Commons^™

Computational Simulation Of Mass Transport And Energy Transfer In The Microbial Fuel Cell System, Shiqi Ou

Doctoral Dissertations

This doctoral dissertation introduces the research in the computational modeling and simulation for the microbial fuel cell (MFC) system which is a bio-electrochemical system that drives a current by using bacteria and mimicking bacterial interactions found in nature. The numerical methods, research approaches and simulation comparison with the experiments in the microbial fuel cells are described; the analysis and evaluation for the model methods and results that I have achieved are presented in this dissertation.

The development of the renewable energy has been a hot topic, and scientists have been focusing on the microbial fuel cell, which is an environmentally-friendly …

Swelling-Etching Characterization Of Copper (I) Oxide - Pdms For The Development Of Micro/Nano - Particles Composite Mems Corrosion Sensor, Abdoul Kader Maiga

Graduate Theses and Dissertations

The primary objective for this thesis is to contribute to the understanding of the oxide removal process for a corrosion sensing device. The goal for designing such a device is for monitoring corrosion on metallic structures. The sensing material (6.35mm x 1mm discs) of the device is composed of copper (I) oxide particles mixed in some polydimethylsiloxane (PDMS). The PDMS, “housing,” is meant for controlling the oxidation rate through the sensing material. A solvent was used to facilitate the etchant diffusion through the PDMS matrix. Toluene and acetic acid were the ideal solvent and etchant, respectively, for carrying out the …

Effects Of Biomass Moisture Content On Volatile Flame Length During Cofiring With Coal, Matthew Pollard

McKelvey School of Engineering Theses & Dissertations

Cofiring biomass with coal can contribute to meeting Renewable Portfolio Standards (RPS) and reduce pollutant emissions. The physical characteristics and composition of biomass can vary significantly, which can affect the combustion characteristics. When cofiring biomass with coal, these differences can impact the structure of the volatile flame, the region where combustion of volatiles dominates. The length and location of the volatile flame is important to flame stability and determines the location and extent of volatile release. This has an effect on pollutant emissions, such as NOx (nitrogen oxides). Previously, the effects of parameters such as cofiring ratio, particle size, and …

Characterization Of Nano-Porous Si-Cu Composites To Enhance Lubricant Retention Impacting The Tribological Properties Of Sliding Surfaces, Julius Sheldon Morehead

Graduate Theses and Dissertations

As the expectations for modern machinery's tribological and thermal performances continue to rise, the retention of lubricant on the contact surfaces of their sliding components becomes an increasingly important issue. Friction and wear cause heat-related failures which lead to catastrophic damage to machinery. Evaporation of a lubricant's volatile constituents as well as lubricant migration leads not only to a reduction in lubricant quantity but also in its quality, thus facilitating component failures. In order to enhance component reliability, the surface should incorporate features that actively retain lubricants. The unique properties of nano-porous topographies such as their high surface area-to-volume ratio …

Modeling Of Biomass Torrefaction And Pyrolysis And Its Applications, Jordan L. Klinger

Dissertations, Master's Theses and Master's Reports - Open

Utilizing biomass provides a possible near-term alternative solution for fossil energy dependence in both electricity generation and transportation. Though thermochemical conversion can produce solid/liquid fuels that are compatible in existing infrastructure, detailed scientific chemical and mechanistic understanding are still being developed. In contribution to these efforts, this work is focused on development of a semiempirical, lumped parameter, chemical kinetic model to describe the degradation of woody biomass.

The initial kinetic model was developed in the torrefaction region to describe the gas-phase evolution of products (water, organic acids, permanent gases, and furfural) through a three consecutive reaction model. In this model, …

Modeling Of Spallation Phenomenon In An Arc-Jet Environment, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical Engineering

Space vehicles, while entering the planetary atmosphere, experience high loads of heat. Ablative materials are commonly used for a thermal protection system, which undergo mass removal mechanisms to counter the heat rates. Spallation is one of the ablative processes, which is characterized by the ejection of solid particles from the material into the flow. Numerical codes that are used in designing the heat shields ignore this phenomenon. Hence, to evaluate the effectiveness of spallation phenomenon, a numerical model is developed to compute the dynamics and chemistry of the particles. The code is one-way coupled to a CFD code that models …