allow E. coli to consume xylose and glucose, two ubiquitous and industrially relevant microbial feedstocks, simultaneously was implemented and systematically evaluated for its effects on L-phenylalanine (Phe; a precursor to many microbially-derived aromatics such as 2PE) production. Ultimately, by incorporating this mutation into a Phe overproducing strain of E. coli, improvements in overall Phe titers, yields and sugar consumption in glucose-xylose mixed feeds could be obtained. While upstream efforts to improve precursor availability are necessary to ultimately reach economically-viable production, the effect of end-product toxicity on production metrics for many aromatics is severe. By utilizing a transcriptional profiling technique (i.e., RNA sequencing), key insights into the mechanisms behind styrene-induced toxicity in E. coli and the cellular response systems that are activated to maintain cell viability were obtained. By investigating variances in the transcriptional response between styrene-producing cells and cells where styrene was added exogenously, better understanding on how mechanisms such as the phage shock, heat-shock and membrane-altering responses react in different scenarios. Ultimately, these efforts to diversify the collection of microbially-produced aromatics, improve intracellular precursor pools and further the understanding of cellular response to toxic aromatic compounds, give insight into methods for improved future metabolic engineering endeavors.
This thesis discusses the yield analysis process for determining the efficacy of experimental changes to a semiconductor manufacturing line, specifically within the chemical mechanical planarization department. Three yield analysis projects were analyzed and related to relevant literature to determine how the changes might impact overall semiconductor yield.
The cosmetic industry utilizes plastic for most of its packaging, as it is a cheap option that produces packaging that is highly durable and resistant to many chemicals. Polyethylene terephthalate (PET) is the most commonly used plastic in cosmetic packaging, and is an ideal candidate for recycling due to their short lifespan and low diffusion coefficient. However, cosmetic packaging is often not recycled properly due to its small size, contributing to the growing global plastic waste problem. If a sustainable closed-loop system was created where cosmetic packaging was created using purely recycled PET, then the amount of plastic produced could be reduced. By examining the mechanical properties of recycled composite PET from the cosmetic industry, conclusions can be drawn about its applicability in cosmetic packaging. The water absorption, UV-visible absorbance, and tensile strength was tested for recycled composite PET to predict how the material would perform if it was used in cosmetic packaging. It was found that the recycled composite PET did not perform as well as virgin PET in terms of water absorption and tensile strength, but performed similarly in reference to UV-visible absorbance. More research needs to be done to further characterize the mechanical properties of recycled composite PET before it can be used in cosmetic packaging, but this study analyzes three of the most prominent aspects found in cosmetic packaging.
Temperature swing adsorption is a commonly used gas separation technique, and is being<br/>further researched as a method of carbon capture. Carbon capture is becoming increasingly<br/>important as a potential way to slow global warming. In this study, algae-derived activated<br/>carbon adsorbents were analyzed for their carbon dioxide adsorption effectiveness.<br/>Algae-derived carbon adsorbents were synthesized and then studied for their adsorption<br/>isotherms and adsorption breakthrough behavior. From the generated isotherm plots, it was<br/>determined that the carbonization temperature was not high enough and that more batches of<br/>adsorbent would have to be made to more accurately analyze the adsorptive potential of the<br/>algae-derived carbon adsorbent.