Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 180-217).

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Bert Bras; Committee Member: David Rosen; Committee Member: Dayna Baumeister; Committee Member: Janet Allen; Committee Member: Jeannette Yen; Committee Member: Matthew Realff. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Yes / The retention of photochemical properties of individual chromophores is a key feature of biological light harvesting complexes. This is achieved despite extensive aggregation of the chromophores, which in synthetic chromophore assemblies often yields a change in spectral characteristics. As an alternative approach towards mimicking biological light harvesting complexes, we report the synthesis of porphyrin assemblies which retained the photochemical properties of the individual chromophore units despite their substantial aggregation. These new materials highlight a new bottom-up approach towards the design and understanding of more complex biomimetic and naturally occurring biological systems. / Seventh Framework Programme (European Commission) (FP7), Engineering and Physical Sciences Research Council (EPSRC), Royal Society (Great Britain)

The goal of this project was to design networked arrays of cricket biosensors capable of localizing sources such as footsteps within dangerous environments, with a possible application to earthquake detection. We utilize the cricket's natural ability to localize low frequency (5 Hz - 600 Hz) acoustic sources using hair-covered appendages called cerci. Whereas previous investigations explored crickets' neurological response to near field flows generated by single frequency steady-state sounds, we investigated the effects of transient waveforms, which better represent real world stimuli, and to which the cercal system appears to be most reactive. Extracellular recording electrodes are permanently implanted into a cricket's ventral nerve cord to record the action potentials emanating from the cerci. In order to calibrate this system, we attempt to find the relationships between the frequency and direction of acoustic stimuli and the neurological responses known as spike trains, which they elicit. The degree of habituation to repeated signals that exists in most neurological systems was also experimentally measured. We process the signals to estimate frequency and directionality of near field acoustic sources. The design goal is a bionic cricket-computer system design capable of localizing low frequency near field acoustic signals while going about its natural activities such as locomotion.

Catalysis is an important part of chemistry. This is also reflected in the chemical industry where 85-90 % of all products are made catalytically. Also nature employs catalysts, i.e. enzymes, for its reactions. To improve on the already existing catalysts one can learn a lot from nature which often uses earth-abundant elements in the enzymes which have also been optimized and finely tuned for billions of years. To gain a deeper understanding of both enzymatic and artificial catalysis one needs to investigate the mechanism of the catalytic process. But for very efficient catalysts with turnover frequencies of several thousand per second this is not easy, since an investigation of the mechanism involves resolving intermediates in the catalytic cycle. The intermediates in these instances are short-lived corresponding to their turnover frequencies. A maximum turnover frequency of 1,000 s-1 e.g. means that each catalyst goes through the whole catalytic cycle in 1 ms. Therefore time-resolved techniques are necessary that have a faster detection speed than the turnover frequency of the catalyst. Flash photolysis is a spectroscopic technique with an instrument response function down to 10 ns.  Coupling this technique with mid-infrared probing yields an excellent detection system for probing different redox and protonation states of carbonyl metal complexes. Since many catalysts as well as natural enzymes involved in water splitting are metal carbonyl complexes this is an ideal technique to monitor the intermediates of these catalysts. Chapter 3 covers the investigation of [FeFe] hydrogenases, enzymes that catalyze the reduction of protons to hydrogen in nature. Chapter 4 investigates the intermediates of biomimetic complexes, resembling the active site of natural [FeFe] hydrogenases. Chapter 5 covers the insights gained from investigating other catalysts which are also involved in water splitting and artificial photosynthesis.

Self-assembly, templation and biomimetics are three important, overlapping areas in supramolecularChemistry. Some contributions to these three areas are introduced. Novel substituted trispyridylmethanol derived ligands were synthesized to mimic the active site of carbonic anhydrase. The key two-step process in constructing the trispyridylmethanol core structure is proven to be more efficient than the traditional one-step synthesis. Self-assembly is a very efficient way to form nanoscale structure from relatively simple subunits. Tetraphenylmethane-based subunits were synthesized. The result of self-assembly reactions demonstrated the formation of 1~3 nm sized molecules in one step. Potential multi-generation self-assembly on this subunit is also discussed. A novel and efficient approach for the synthesis of large aromatic crown ethers, using resorcinarenes as templates, has been developed. This simple threestep process generated a new family of aromatic crown ethers in up to 50% overall yield. As intermediates from these three-step syntheses, a large variety of molecular "baskets", which have been shown to be excellent hosts for adamantanes, have also been obtained.

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Paul Harrison. Includes bibliographical references (leaves 192-207).

Thesis (M.S.)--University of Nevada, Reno, 2004. / "December 2004." Includes bibliographical references (leaves 107-109). Online version available on the World Wide Web.

Thesis (Ph.D.)--Drexel University, 2007. / Includes abstract and vita. Includes bibliographical references (leaves 204-213).