Engineering Commons^™

Prototype Instrument Development For Measuring Directionality Of Aerosol Light Scattering, Esther K. Monroe

McKelvey School of Engineering Theses & Dissertations

Investigation of aerosol interactions with electromagnetic waves provides insights into the scattering particles. Aerosol phase function, an angular distribution of scattered light, is a value required to calculate parameters used in direct radiative forcing (DRF) models in the atmosphere. Currently no direct measurement of phase function is available hence it is estimated from ground observations such as backscatter fraction b and subsequently relating the parameters via Henyey-Greenstein (HG) approximation. This method has shown to introduce errors in radiation transfer models. HG phase function, in particular, does not account for particle microphysical properties such as shape and refractive index. Given the …

Fundamental Studies Of Solid-Fuel Combustion Using A Two-Stage Flat-Flame Burner, Adewale Ayodeji Adeosun

McKelvey School of Engineering Theses & Dissertations

Innovative coal technologies are essential for addressing concerns about air pollution and global climate change. A key pathway to advancing these technologies is through developing a thorough understanding of the fundamental physical and chemical processes that occur during coal combustion. Ignition influences many aspects of coal combustion, including flame stability, submicron aerosol evolution, and char burnout. As important as ignition and these associated processes are, they are challenging to study because they depend on many factors, such as the combustion environment, particle size, and particle-particle interactions.

While there have been many studies of coal ignition, none have studied the process …

Novel Applications Of Electrostatic Precipitators In Coal - Biomass Combustion Systems, He Jing

McKelvey School of Engineering Theses & Dissertations

Pulverized coal combustion is an important source of electricity production worldwide. However, it is also a primary air pollution emission (particulate matters, mercury, etc.) source. Electrostatic precipitators (ESPs) are widely used in coal-fired power plants to control particulate matters. This dissertation contributes in the study of the pollution formation from coal combustion processes and pollution control based on ESPs in the following three aspects: (1) explore novel applications of ESPs in particulate matters and mercury removal; (2) develop and evaluate an compact electrostatic precipitator for sampling purpose, which can support offline fly ash particle analysis; (3) study the submicrometer particle …

Smoke Aerosol Characterization For Spacecraft Fire Detection Systems, Marit Elisabeth Meyer

McKelvey School of Engineering Theses & Dissertations

Appropriate design of fire detection systems requires knowledge of both the expected fire signature and the background aerosol levels. Terrestrial fire detection systems have been developed based on extensive study of terrestrial fires. Unfortunately there is no corresponding data set for spacecraft fires and consequently the fire detectors in current spacecraft were developed based upon terrestrial designs. There are a number of factors that affect the smoke particle size distribution in spacecraft fires. In low gravity, buoyant flow is negligible which causes particles to concentrate at the smoke source, increasing their residence time, and increasing the transport time to smoke …

Development & Testing Of Novel Atmospheric Chemistry Technologies, Peter Johnson Mellott

All Theses and Dissertations (ETDs)

Atmospheric aerosols play an important role in global atmospheric chemistry and climate and have a detrimental impact on human health. Advancements in measurement technologies allow for better monitoring of atmospheric composition and dynamics, creating better predictive models and understanding of atmospheric chemistry and physics. Gas and particle atmospheric oxidation is poorly understood. In order to create a better understanding of atmospheric oxidation, the following equipment was developed: 1) a Potential Aerosol Mass: PAM) flow reaction chamber was developed to create reproducible steady-state oxidation of organic species in a controlled laboratory setting, 2) a custom combustion chamber for introduction of realistic …