Bucknell Dance Company Spring 1990 Performance

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ARISTOTLE AND THE IMPORTANCE OF VIRTUE IN THE CONTEXT OF THE POLITICS AND THE NICOMACHEAN ETHICS AND ITS RELATION TO TODAY

While much of Aristotle's works are preserved in various volumes, two of his famous works are the Nichmachean Ethics and the Politics, both of which contain a rich compilation of ethical and political thought. In the Ethics, Aristotle describes a thorough understanding of ethical and intellectual virtue. By pursuing these virtues, Aristotle argues that a person can achieve a life of fulfilling happiness. The ideal polis as described in the Politics serves as a place where the virtuous life is attained in the best manner.Citizens who pursue virtue make the polis better, and the rulers that guide the polis ensure that the citizens have every opportunity to pursue the virtuous life. In this thesis, I see how relevant Aristotle's theory is by laying out the basic principles of the Ethics and the Politics and the connections between the two works. Indoing so, I found that Aristotle's ideal theory points out a significant flaw in our political system: the fact that we do not share a common moral conception such as the one concerned with the virtuous life as Aristotle proposes. This does not suggest thatAristotle's view was actualized during his time period, but that Aristotle conceives of an ideal life and an ideal polis that could be realized. Certainly there are issues with Aristotle's thesis concerning the inferiority of slaves and women. But what is morepoignant is the impracticality of instituting a shared common conception when today's political system permits various ideas about ethics and morality.

Synthesis and Surface Modification of CdSe and CdS Quantum Dots Exhibiting High Quantum Yield

The thesis investigates the effect of surface treatment with various reducing and oxidizing agents on the quantum yield (QY) of CdSe and CdS quantum dots (QDs). The QDs, as synthesized by the organometallic method, contained defect sites on their surface that trapped photons and prevented their radiative recombination, therefore resulting in adecreased QY. To passivate these defect sites and enhance the QY, the QDs were treated with various reducing and oxidizing agents, including: sodium borohydride (NaBH4), calcium hydride (CaH2), hydrazine (N2H4), benzoyl peroxide (C14H10O4), and tert-butylhydroperoxide (C4H10O2). It was hypothesized that the reducing/oxidizing agents reduced the ligands on the QD surface, causing them to detach, thereby allowing oxygen from atmospheric air to bind to the exposed cadmium. This cadmium oxdide (CdO) layeraround the QD surface satisfied the defect sites and resulted in an increased QY. To correlate what effect the reducing and oxidizing agents were having on the optical properties of the QDs, we investigated these treatments on the following factors:chalcogenide (Se vs. S), ligand (oleylamine vs. OA), coordinating solvent (ODE vs.TOA), and dispersant solvent (chloroform vs. toluene) on the overall optical properties of the QDs. The QY of each sample was calculated before and after the various surface treatments from ultra-violet visible spectroscopy (UV-Vis) and fluorescence spectroscopy data to determine if the treatment was successful.From our results, we found that sodium borohydride was the most effective surface treatment, with 10 of the 12 treatments resulting in an increased QY. Hydrazine, on the other hand, was the least effective treatments, as it quenched the QD fluorescence in every case. From these observations, we hypothesize that the effectiveness of the QD surface treatments was dependent on reaction rate. More specifically, when the surface treatment reaction happened too quickly, we hypothesize that the QDs began to aggregate, resulting in a quenched fluorescence. Furthermore, we believe that the reactionrate is dependent on concentration of the reducing/oxidizing agents, solubility of the agents in each solvent, and reactivity of the agents with water. The quantum yield of the QDs can therefore be maximized by slowing the reaction rate of each surface treatment toa rate that allows for the proper passivation of defect sites.