The work described in this thesis is an investigation into the reactivity and possible synthetic applications of aziridinylcarbinyl radicals. These radicals rapidly rearrange via β cleavage, which can proceed by breakage of either the CoN or C-C bond. Cleavage of the latter has been found when the molecule has a phenyl stabilising group attached to the aziridine ring. Chapter I is a review of the known radical reactions involving aziridines whilst chapter 2 discusses the various methods of aziridine syntheses. Chapter 3 outlines the project aims with reference to the potential of directed cleavage of aziridinylcarbinyl radicals in synthesis. Chapter 4, the main body of the work, describes the synthetic routes to aziridines derived from 3-phenyl-2-cyclohexen-I-one and indenone. The radical mediated β-cleavage reactions of these is reported and the selectivity of C-C v. CoN bond homolysis has been investigated. Two successful approaches to the target aziridines were involved. I) Conversion of 3-azido-3-phenylcyclohexan-I,2-diol, derived from the epoxide of 3- phenyl-2-cyc1ohexen-I-ol, to the aziridine via reaction with triphenylphosphine. Subsequent methylation and formation of the thiocarbonylimidazolide gave the radical precursor Nmethyl- 5-[imidazol-I-yl(thiocarbonyl)oxy]-I-phenyl-7-azabicylo[4.1.0]heptane. In the course of this work, several unusual cyclic thiocarbonates resulting from the reaction of 3-azido-3- phenylcyclohexan-I,2-diol and 2-azido-3-phenylcyclohexan-I,3-diol with I, I 'thiocarbonyl diimidazole were isolated. 2) Formation of N-(2-ethylquinazolinonyl)-I-phenyl-7-azabicyclo[4.1.0]heptan-5-01 from the reaction of 3-amino-2-ethyl-4(3H)-quinazolinone with 3-phenyl-2-cyc1ohexen-I-ol in the presence of lead tetraacetate. These aziridines show interesting acid-catalysed rearrangements to diazadioxabicyclo[2.2.2]octanes. Formation of the thiocarbonylimidazolide then gave the radical precursor. A number of other aziridines have been prepared using this methodology. It has been found that in all cases the precursors undergo CoN bond homolysis under radical conditions. These results are discussed and conclusions are drawn. Suitable future work is also suggested.

The entirety of the investigation discussed in this paper was confined to a study of the spin resonance properties of unpaired electrons of an organic free radical. In the remainder of the paper the theory of electron spin resonance, the apparatus used in the investigation, and the experimental results obtained are discussed in that order.

We demonstrate the uncountable cofinality of the automorphism groups of various linear and partial orders. We also relate this to the ‘Bergman’ property, and discuss cases where this may fail even though the cofinality is uncountable.

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Synthesizing proteins for use in therapeutics is restrained by, in part, contaminants in in vivo expression systems and limited production capacity of in vitro systems. Cell free expression (CFE) systems have emerged as a potential alternative for protein expression because of the inherently lower contents of contaminants, and their flexible modular design that allows the addition of factors that aid in synthesis of complex products. Here, we investigate and establish an in-house Escherichia coli-based cell free protein synthesis (CFPS) system, explore different CFPS commercial kits, develop assays to test performance of these systems and identify potential rules that dictate expression levels. Using CFE, we were able to test different vectors and conditions of system, as well as scale-up protein synthesis reactions. In conclusion, this work shows that CFPS is a functional and easy-to-use platform and can potentially meet the requirements for the synthesis of therapeutics.

After Horses is a a collection of narrative and verse poems centered loosely around the idea or theme of how to create meaning from the fracture and detritus of daily life. Also under obsessive consideration throughout: loneliness, the risk of human connection, the risk of a lack of human connection, the impossibility of language, hope as illuminating and good thing, hope as desperate and devouring thing, and an underlying fear and awareness of the fact that no one can be sure of what ultimately matters, anyway. / Master of Fine Arts

Piezoelectric materials find applications in number of devices requiring inter-conversion of mechanical and electrical energy.  These devices include different types of sensors, actuators and energy harvesting devices. A number of lead-based perovskite compositions (PZT, PMN-PT, PZN-PT etc.) have dominated the field in last few decades owing to their giant piezoresponse and convenient application relevant tunability. With increasing environmental concerns, in the last one decade, focus has been shifted towards developing a better understanding of lead-free piezoelectric compositions in order to achieve an improved application relevant performance.  Sodium potassium niobate (KxNa1-xNbO3, abbreviated as KNN) is one of the most interesting candidates in the class of lead-free piezoelectrics. Absence of any poisonous element makes it unique among all the other lead-free candidates having presence of bismuth. Curie temperature of 400"C, even higher than that of PZT is another advantage from the point of view of device applications. Present work focuses on the development of fundamental understanding of the crystallographic nature, domain structure and domain dynamics of KNN. Since compositions close to x = 0.5 are of primary interest because of their superior piezoelectric activity among other compositions (0 < x < 1), crystallographic and domain structure studies are focused on this region of the phase diagram. KNN random ceramic, textured ceramic and single crystals were synthesized, which in complement to each other help in understanding the behavior of KNN. K0.5Na0.5NbO3 single crystals grown by the flux method were characterized for their ferroelectric and piezoelectric behavior and dynamical scaling analysis was performed to reveal the origin of their moderate piezoelectric performance. Optical birefringence technique used to reveal the macro level crystallographic nature of x = 0.4, 0.5 and 0.6 crystals suggested them to have monoclinic Mc, monoclinic MA/B and orthorhombic structures respectively. Contrary to that, pair distribution function analysis performed on same composition crystals implies them to belonging to monoclinic Mc structure at local scale. Linear birefringence and piezoresponse force microscopy (PFM) were used to reveal the domain structure at macro and micros scales respectively. A noble sintering technique was developed to achieve > 99% density for KNN ceramics. These high density ceramics were characterized for their dielectric, ferroelectric and piezoelectric properties. A significant improvement in different piezoelectric coefficients of these ceramics validates the advantages of this sintering technique. Also lower defect levels in these high density ceramics lead to the superior ferroelectric fatigue behavior as well. To understand the role of seed crystals in switching behavior of textured ceramic, highly textured KNN ceramics (Lotgering factor ~ 88 %) were synthesized using TGG method. A sintering technique similar to one employed for random ceramics, was used to sinter textured KNN ceramics as well. Piezoresponse force microscopy (PFM) study suggested these textured ceramics to have about 6¼m domains as compared to 2¼m domain size for random ceramics.  Local switching behavior studied using switching spectroscopy (SS-PFM) revealed about two and half time improvement of local piezoresponse as compared to random counterpart. / Ph. D.

The problem of this study is to make an appraisal of laissez-faire, and its aims, methods, and accomplishments in its rise to pinnacle heights, its philosophy, and finally its decline in the maelstrom of society demanding more security, today, than ever before, in our standards of economy and living.