Corrosion Behavior of H-Pile Steel in Different Soils

This dissertation aimed to study the corrosion performance of carbon steel in different soils, collected from the state of Wisconsin. Carbon steel specimens (as-received) as well as steel embedded in mortar (steel-mortar) specimens, to simulate the realistic H-pile design in bridges, were used in this investigation. Both as-received steel and steel-mortar specimens were embedded in as-received soils, with different physiochemical properties, i.e. pH, moisture content, resistivity, chloride content, sulfate and sulfite contents, and the mean total organic carbon concentration, for more than one year. Both specimen types were also embedded in the same as-received soils, but with increased chloride content to 3% by weight of chloride ions for more than one year. In addition, the surface of three identical as-received specimens was modified using the sandblasting method for 5 minutes. These specimens were embedded in one of the collected soils. Different electrochemical measurements were conducted on the specimens to evaluate the corrosion activity of the steel in these soils. The results showed a comparable corrosion activity of the steel-mortar specimens in all soils compared to the as-received specimens in the same soil both with and without chlorides, except for soils collected from Wausau. No correlation between the available physiochemical data and the observed results was determined. No information on the type and population of the bacteria in the collected soils was available. Perhaps, this information could explain the observed results. In all cases, there was a galvanic current flowing between specimens in chloride-free and chloride contaminated soils. In addition, corrosion potential values of all specimens remained relatively stable both before and after addition of chlorides, suggesting just measuring the corrosion potential may not be an efficient method to monitor the change of corrosion behavior of steel in the soil. The results of electrochemical experiments also showed significant improvement in corrosion resistance of sandblasted specimens compared to the as-received specimens

Development of Perfluorocarbon Nanoemulsions for Delivery of Therapeutic Nucleic Acids

Local pulmonary administration of therapeutic siRNA represents a promising approach to the treatment of lung fibrosis, which is currently hampered by inefficient delivery. Pancreatic cancer (PC) is a fatal human cancer whose progression is highly dependent on the nervous tumor microenvironment. siRNA delivery has been well studied as a promising therapeutic agent for several disease, including the pulmonary fibrosis and cancer. Perfluorocarbon nanoemulsions have been studied in the treatment of various diseases as drug delivery systems. We report development of perfluorooctylbromide (PFOB) nanoemulsions as a platform to facilitate delivery and penetration of a therapeutic siRNA to pulmonary fibrosis lung and orthotopic pancreatic tumors. PCX@PFOB emulsion, which contained the polymeric CXCR4 antagonist PCX with PFOB, is a dual functional emulsion to inhibit CXCR4 and deliver siRNA. This dissertation hypothesized that inhibition of CXCR4 by PCX@PFOB emulsion combined with siRNA delivery cooperatively enhances the pulmonary fibrosis and PC treatment

High-performance code generation for polynomials and power series

Newton iteration is a versatile tool. In this thesis, we investigate its applications to the computation of power series solutions of first-order non-linear differential equations. To speed-up such computations, we first focus on improving polynomial multi­ plication and its variants: plain multiplication, transposed multiplication and short multiplication, for Karatsuba’s algorithm and its generalizations. Instead of rewriting code for different multiplication algorithms, a general approach is designed to output computer-generated code based on multiplication graph representations. Next, we investigate the existing Newton iteration algorithms for differential equa­ tion solving problems. To improve their efficiency, we recall how one can reduce the amount of useless computations by using transposed multiplication and short mul­ tiplication. We provide an optimized code generator that applies these techniques automatically to a given differential equation