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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.
91

Evidence for a conformationally sensitive anion binding site on ribulose -1,5-bisphosphate carboxylase/oxygenase isolated from comfrey

Bonsall, Robert F January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
92

Regulation of anion secretion in human airway epithelial cells /

Wang, Dong. January 2009 (has links)
Includes bibliographical references (p. 85-103).
93

Analysis of atomic and molecular negative ions in a constant electric field using a resolvent method

Jung, Jin-Wook, 1973- 09 October 2012 (has links)
We use a resolvent method to study atomic and molecular negative ions in a constant electric field potential which is linear. When a linear potential is applied, it makes the shape of the original potential of the system slanted into one side and thus changes the time evolution of the system. In particular, a bound state can be changed into a state, so called 'quasibound' state, which is not bound anymore and decays into the continuum due to the presence of the linear potential. For an atomic system, we use an attractive delta function fixed at the origin for the interaction potential and solve the single particle Schrodinger equation. For an actual system, we choose the Hydrogen negative ion, and determine the strength of the delta function so that the bound state energy can simulate the electron affinity of the Hydrogen. We find the resolvent of the system and the poles of the resolvent in the analytically continued region. From the patterns of the location of the poles, we can view the one delta function system as a combination of three simple systems. Though they are not exactly the same, this view gives some insight on the system. From the residue at each pole, complex eigenstates are constructed and used for the calculation of the survival probability of an initial state. For the same initial state, we calculate the photodetachment rate when a time-periodic potential is applied. The plot for the photodetachment rate shows peaks at certain incident photon energies. These are compared with an experimental data and give a good agreement although our model is just one dimensional. For a molecular system, two delta function model is suggested by us as an extension of the one delta function model. We find the resolvent of the system and the pole structure from the resolvent. The complex eigenstates are constructed from the residue of the resolvent at each pole. We try to model Oxygen molecular negative ion and determine the strength of the delta function and the distance between the delta functions so that they are consistent with the electron affinity and the internuclear distance of the Oxygen molecule. We also calculate the survival probability and the photodetachment rate of an initial state and find that the plot of the photodetachment rate has similar shape to that of the one delta function model. / text
94

Isoamethyrin analogues and cyclo[n]pyrrole as sensors for cations and anions

Melfi, Patricia Jennifer, 1979- 28 August 2008 (has links)
The increased worldwide interest in nuclear power and the politically charged threat of nuclear weapons release has made understanding the components, as well as the waste, of nuclear energy an important area of research. More specifically, the identification and selective extraction of the dioxoactinide cations uranyl (UO₂²⁺) and plutonyl (PuO₂⁺), low valent actinides scuh as Am³⁺ or Cm³⁺ and various anions, such as pertechnetate (TcO₄⁻), is essential in the event of a weapons release or the spill of nuclear waste. It has been previously demonstrated that the expanded porphyrin [24]hexaphyrin(1.0.1.0.0.0), commonly referred to as isoamethyrin, displays a dramatic color change, from golden yellow to red, upon coordination of uranyl, neptunyl and plutonyl cations. Chapter 2 details quantitative investigations of isoamethyrin with the uranyl cation as well as the interactions of isoamethyrin with other, potentially competing, cations. This work was carried out in order to assess the ability of isoamethyrin to serve as a colorimetric sensor for the actinide cations. Chapter 3 describes the synthesis and properties of periphery-modified isoamethyrin analogues. The addition of functional groups to this expanded porphyrin allows for immobilization onto a solid support and may enhance its utility as a sensor. Chapter 4 presents the preliminary investigations into the metalation and anion binding properties of a new series of macrocycles, the cyclo[n]pyrroles. Chapter 5 provides experimental methods and characterization data. / text
95

Syntheses and studies of sapphyrins and anion receptors

Cho, Dong Gyu, 1970- 29 August 2008 (has links)
Polypyrrolic (or aromatic) macrocycles have attracted considerable recent interest due to their potential utility in various applications, including as novel materials, anion receptors, and therapeutic leads. In order to explore further the range and utility of this generalized class of molecules, various sapphyrin and sapphyrin analogues were synthesized. Among the new compounds prepared is an inverted sapphyrin, a species that displayed weak, but noticeable aromaticity. Another new system, benzoxasapphyrin was found to display a reduced anion binding affinity compared to other analogous macrocycles. Finally, several derivatized sapphyrins were prepared as potential anticancer leads. Separate from the above, efforts were made to develop anion receptors based on the indole motif. This substructure plays a key role is stabilizing a range of non-covalent interactions in complex biological structures. However, prior to the present study, indole-type hydrogen bonding donors had not been widely used to prepare synthetic anion receptors. Accordingly, a diindolyl quinoxaline system was prepared; it served to demonstrate that small molecule indole receptors can effectively bind phosphate anions in organic media. Finally, a set of cyanide anion indicators were prepared; these were predicated on the use of a cyanide-specific reaction, namely the benzil rearrangement reaction. The benzil reaction-based indicators produced in this way were found to be quite selective for the cyanide anion in organic solvents. Further, their study helped provide insights into the mechanism of this as-yet not fully studied reaction. In the context of developing this specific anion indicator, a review of other reaction-based indicators was reviewed. This is provided in Chapter 3. / text
96

Characterization of ionic liquids

De La Osa, Maria Jose Torres January 2001 (has links)
No description available.
97

Single- and multiphoton infrared laser spectroscopy of atomic negative ions /

Scheer, Michael. January 1998 (has links)
Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references. Also available via World Wide Web.
98

Layered double hydroxides as anion- and cation-exchanging materials

Richardson, Mickey Charles. Braterman, Paul S., January 2007 (has links)
Thesis (Ph. D.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.
99

The mobility of large anions in crystals with the fluorite structure

Lavers, Philip S. January 2002 (has links)
Thesis (M.Sc.(Hons))--University of Wollongong, 2002. / Typescript. Bibliographical references: leaf 113-122.
100

Using alpha-aminoxy acids as building blocks to construct anion receptors and synthetic chloride channels

Li, Xiang, January 2008 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

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