Engineering Commons^™

Multi-Scale Studies To Develop A Holistic Understanding Of Solid Fuel Combustion At Residential Scale, Sameer Patel

McKelvey School of Engineering Theses & Dissertations

Nearly 3 billion people rely on solid fuels for their cooking and heating needs, classifying them as “energy poor”. This poverty can be attributed to several factors, including a lack of resources (fuel), inefficient infrastructure (production and distribution), limited purchasing power (poverty), and ill-devised policies. Solid fuels, such as biomass, coal, and dung cakes, are burned in inefficient cookstoves. They generate products of incomplete combustion (PIC), such as CO, particulate matter (PM), and CH4, causing household air pollution (HAP) whose adverse impacts on both health and the environment have been well established.

HAP causes diseases such as chronic obstructive pulmonary …

Abiotic- And Biotic-Formation Of Manganese Oxides And Their Fate In Environmental Systems, Haesung Jung

McKelvey School of Engineering Theses & Dissertations

Manganese (hydr)oxide (Mn (hydr)oxide) minerals are ubiquitous in aquatic and terrestrial environments. These minerals have high surface areas and are highly sorptive and redox active. From decades of accumulated knowledge about natural redox cycling, we have found that Mn (hydr)oxides play critical roles as electron donors and acceptors in elemental geochemical cycling and biological metabolisms in nature. Thus, Mn (hydr)oxides have garnered increasing interest to understand natural systems. Considering the variety of redox reactions with Mn (hydr)oxides in nature, it is also expected that there should be diverse pathways to form Mn (hydr)oxides through abiotic and biotic processes. Previous studies …

Two-Component Hydrogel As Biomimetic Vitreous Substitutes, Sruthi Santhanam

McKelvey School of Engineering Theses & Dissertations

The vitreous humor of the eye is a biological hydrogel principally composed of fibrillary collagen interspersed with semi-flexible polyelectrolyte, hyaluronic acid (HA). Certain pathological conditions necessitate its removal and replacement. Current vitreous substitutes, such as silicone oils and perfluorocarbons, are hydrophobic, do not resemble the properties of the vitreous, and have known complications. An ideal vitreous substitute should have properties of the natural vitreous, perform its functions, and be biocompatible in the eye. Inspired by the structure and composition of the natural vitreous, we used bio-mimicry to develop an injectable two-component hydrogel. The hydrogel is composed of a fibrillary gellan, …

Designing Metabolite Biosensors And Engineering Genetic Circuits To Regulate Metabolic Pathways, Di Liu

McKelvey School of Engineering Theses & Dissertations

Microbial production of chemicals has provided an attractive alternative to chemical synthesis. A key to make this technology economically viable is to improve titers, productivities, and strain robustness. However, pathway productivities and yields are often limited by metabolic imbalances that inhibit cell growth and chemical production. In contrast, natural metabolic pathways are dynamically regulated according to cellular metabolic status. Dynamic regulation allows cells to adjust metabolite concentrations to optimal levels and avoid wasting carbon and energy. Inspired by nature, synthetic regulatory circuits have shown great promise in improving titers and productivities, because they can balance the metabolism by dynamically adjusting …

Fundamental Studies Of Flame Structure Through Laser Plasma Diagnostics, Wendong Wu

McKelvey School of Engineering Theses & Dissertations

Increasing concerns about air pollution and global climate change are drawing attention to the need for efficiency improvements and emission reductions for combustion processes, which account for more than 85% of energy production in United States. Combustion efficiency and emissions are affected by the mixing and reacting of fuel and oxidizer. Understanding such behavior plays a critical role in flame structure studies and combustion optimization. However, experimentally obtaining mixture fraction, which is a widely used quantity to describe the mixing behavior, has proven to be a challenge, especially for heavier hydrocarbon fuels or fuel rich flames. Moreover, measuring flame temperature …

Studies In Pressurized Oxy-Combustion: Process Development And Control Of Radiative Heat Transfer, Akshay Gopan

McKelvey School of Engineering Theses & Dissertations

Fossil fuels supply over 80% of the world’s primary energy and more than two-thirds of the world’s electricity. Of this, coal alone accounts for over 41% of the electricity supplied globally. Though coal is globally well-distributed and can provide stable and reliable energy on demand, it emits a large amount of carbon dioxide—a greenhouse gas responsible for global warming. Serious concerns over the implication of the increased global temperature have prompted the investigation into low carbon energy alternatives. The idea of capturing the carbon dioxide emitted from the combustion sources is considered as one of the viable alternatives. This would …

Computational Fluid Dynamics Modeling And Simulations Of Fast Fluidized Bed And Moving Bed Reactors For Chemical Looping Combustion, Mengqiao Yang

McKelvey School of Engineering Theses & Dissertations

Chemical-looping combustion (CLC) is a next generation carbon capture technology with high efficiency and low cost. To assess the potential of this technology for industrial scale power plants, thousands of laboratory scale and many pilot-scale plants have been designed and tested. In recent years, to obtain a thorough understanding of the hydrodynamic behavior inside the reactors and chemical looping combustion process, high-fidelity numerical simulation using Computational Fluid Dynamics(CFD) have been performed. However, CFD simulations in the literature have been limited reported compared to the laboratory scale experiments.

In this thesis, cold flow simulations of a CLC fuel reactor are performed …

Sub 2 Nm Particle Characterization In Systems With Aerosol Formation And Growth, Yang Wang

McKelvey School of Engineering Theses & Dissertations

Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. The knowledge on particle formation in early stages can also be applied …