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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Monitoring Chain Dynamics by Luminescence Using a Long-Lived Ruthenium Dye

Quinn, Cristina January 2006 (has links)
The purpose of this research project was to determine the feasibility of labelling a water-soluble polymer with a water-soluble dye and quencher. The water-soluble dye chosen was bis-(2,2-bipyridine)-ruthenium(II) -5-amino-1,10-phenanthroline hexafluorophosphate, RuNH2 , with a water solubility of 1×10^−3 mol/L. 3,5-Dinitrobenzyl alcohol was found to be an efficient quencher with a quenching rate constant of 2.7×10^9 M^−1 s^−1 as well as a water-solubility of 5×10^−3 mol/L. Both the dye and quencher were modified in a way such that they could be covalently linked to a polymer. RuNH2 was converted to bis-(2,2-bipyridine)-ruthenium(II)-5-isothiocyanato-1,10- phenanthroline hexafluoro-phosphate, RuNCS, using thiophosgene to yield an active isothiocyanate group. 3,5-Dinitrobenzylamine, DNB-NH2 , was synthesized via tritylamination of the commercially available 3,5-dinitrobenzyl chloride. A synthetic pathway has been established to covalently attach the dye and quencher to poly(N,N-dimethylacrylamide)(PDMA). Luminescence of this system was first characterized in N,N-dimethylformamide (DMF) rather than water to allow for future comparisons to be made between this water-soluble system and the previously established non-water-soluble system. Luminescence analysis of the RuNCS labelled polymers in DMF could be fitted with a sum of three exponentials with the strongest contribution being that of a 1000 ns long-lived species which is characteristic of the free dye. A luminescence decay of a polymer labelled with both RuNCS and DNB-NH2 was acquired and showed static quenching of the ruthenium dye by the quencher.
2

Monitoring Chain Dynamics by Luminescence Using a Long-Lived Ruthenium Dye

Quinn, Cristina January 2006 (has links)
The purpose of this research project was to determine the feasibility of labelling a water-soluble polymer with a water-soluble dye and quencher. The water-soluble dye chosen was bis-(2,2-bipyridine)-ruthenium(II) -5-amino-1,10-phenanthroline hexafluorophosphate, RuNH2 , with a water solubility of 1×10^−3 mol/L. 3,5-Dinitrobenzyl alcohol was found to be an efficient quencher with a quenching rate constant of 2.7×10^9 M^−1 s^−1 as well as a water-solubility of 5×10^−3 mol/L. Both the dye and quencher were modified in a way such that they could be covalently linked to a polymer. RuNH2 was converted to bis-(2,2-bipyridine)-ruthenium(II)-5-isothiocyanato-1,10- phenanthroline hexafluoro-phosphate, RuNCS, using thiophosgene to yield an active isothiocyanate group. 3,5-Dinitrobenzylamine, DNB-NH2 , was synthesized via tritylamination of the commercially available 3,5-dinitrobenzyl chloride. A synthetic pathway has been established to covalently attach the dye and quencher to poly(N,N-dimethylacrylamide)(PDMA). Luminescence of this system was first characterized in N,N-dimethylformamide (DMF) rather than water to allow for future comparisons to be made between this water-soluble system and the previously established non-water-soluble system. Luminescence analysis of the RuNCS labelled polymers in DMF could be fitted with a sum of three exponentials with the strongest contribution being that of a 1000 ns long-lived species which is characteristic of the free dye. A luminescence decay of a polymer labelled with both RuNCS and DNB-NH2 was acquired and showed static quenching of the ruthenium dye by the quencher.
3

Geometrical theory, modeling and applications of channel polarization

Kwon, Seok Chul 12 January 2015 (has links)
Long-term evolution (LTE) standard has been successfully stabilized, and launched in several areas. However, the required channel capacity is expected to increase significantly as the explosively increasing number of smart-phone users implies. Hence, this is already the time for leading researchers to concentrate on a new multiple access scheme in wireless communications to satisfy the channel capacity that those smart users will want in the not-too-distant future. The diversity and multiplexing in a new domain - polarization domain - can be a strong candidate for the solution to that problem in future wireless communication systems. This research contributes largely to the comprehensive understanding of polarized wireless channels and a new multiple access scheme in the polarization domain - polarization division multiple access (PDMA). The thesis consists of three streams: 1) a novel geometrical theory and models for fixed-to-mobile (F2M) and mobile-to-mobile (M2M) polarized wireless channels; 2) a new wireless body area network (BAN) polarized channel modeling; and 3) a novel PDMA scheme. The proposed geometrical theory and models reveal the origin and mechanism of channel depolarization with excellent agreement with empirical data in terms of cross-polarization discrimination (XPD), which is the principal measure of channel depolarization. Further, a novel PDMA scheme utilizing polarization-filtering detection and collaborative transmitter-receiver-polarization (Tx-Rx-polarization) adjustment, is designed considering cellular orthogonal frequency division multiplexing (OFDM) systems. The novel PDMA scheme has large potential to be utilized with the conventional time, frequency, and code division multiple access (TDMA, FDMA, and CDMA); and spatial multiplexing for next-generation wireless communication systems.

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