Thesis (Ph. D.)--School of Mechanical Engineering, Georgia Institute of Technology, 2004. Directed by Richard W. Neu. / Vita. Includes bibliographical references (leaves 269-278).

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xi, 127 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 127).

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Introduction Solid targets for PET and SPECT radionuclides are getting popular. For radiohalogens the limiting factor, beside the high cost of enriched target material is beam current due to poor heat conductivity of the target material(s). We have designed a honeycomb solid target which has advantages over the traditional circular hole de-sign: 1) Even distribution of target material, 2) it takes higher beam current, 3) less target material loss during distillation (1) and 4) no “creeping” (surface tension phenomena) of the target material during distillation. Material and Methods The target (see FIG. 1.) consists of 19 hexagonal 0.3 mm deep openings (see FIG. 2.) thus having 84% transparency/transmission, in a 24×2 mm platinum disk. There is a 10mm circular cavity on the reverse side giving a 200µm thickness of the platinum. The irradiations were performed on an IBA twin 18/18 Cyclon equipped with a Costis sold target system. The target material thickness was ~300mg/cm2 124TeO2 (> 99.9% I.E., Isoflex) with 5% w/w Al2O3 (99.99%, Sigma-Aldrich). The target was irradiated with 14.8MeV protons (18 MeV degraded by 500µm aluminium). Results and Conclusion The target was able to take beam current up to ~35 µA (higher BCs have not yet been investigated); our “traditional” target (10mm circular hole) has a limit of ~ 20 µA. This means that the effective yield is ~ 50 % higher with the honeycomb as compared with the “traditional” target design.

This thesis studies the synthesis of diverse architectures of polymers via the reversible addition fragmentation chain transfer (RAFT) polymerisation process that is one of the most novel and versatile controlled polymerisation techniques. Star polymers, comb polymers, amphiphilic block copolymers, and random copolymers were utilised to fabricate porous films with hexagonal arrangement via a ???bottom-up??? engineering approach, namely a ???breath figure??? technique. The quality (i.e. pore regularity and pore size) of the films was optimised by controlling casting variables including humidity, airflow, concentration of polymer solution, polymer architecture, molecular weight of polymer, substrate, and casting volume. Porous membranes were chemically crosslinked to improve their mechanical strength if required. Furthermore, chemical surface modification of porous films was performed by grafting desired polymer (i.e. PNIPAAm or PAGA) via RAFT polymerisation. The RAFT groups present in the films play a role as anchoring sites for polymerisation, thus the complex initiator immobilising can be avoided in our system. The desired polymer grafting is able to enhance wettability and provide binding sites for adhesion and proliferation of cells. The topography of ungrafted and grafted films was analysed using optical microscopy, scanning electron microscopy, atomic force microscopy, confocal microscopy, ATR-FTIR, and XPS.

Thesis (Ph.D.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (ℓ. 169-178)

Dissertation (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xii, 219 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 202-219).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xi, 107 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 87-89).