Protective helmets used by fire-fighters must be designed to minimize the amount of heat transferred to the users head while providing durability, comfort, and affordable costs. This thesis highlights the evaluation of new helmet technology specifically tailored to high radiant heat environments to advance the state-of-the-art in head protection for this application. The research focused on the assessment of the outer shells of helmets and the properties of the surfaces. The development included the evaluation of radiation heat transfer, in a laboratory environment, to various helmet shell surface constructions. Industry standards were considered, and critiqued. Experiments were designed to isolate critical design variables for measurement and evaluation. Custom, purpose-built laboratory apparatus for testing helmets were designed, explained and utilized in the testing of specimens. Additionally, market demands for firefighting helmets were explored. Helmet durability was specifically addressed with abrasion criteria established and the reflectivity effects of the abraded surfaces evaluated. Resulting from this study, new surface technologies were identified for possible development in future helmet designs. Various surface materials, finishes, and coatings were compared and contrasted to current industry state-of-the-art equipment. The knowledge discovered further advanced modern head protection science in aim of increased safety and performance of fire-fighting personnel.

In this study, we developed a facile method for preparing a superhydrophobic paper surface using a layer-by-layer deposition of polydiallyldimethylammonium chloride (polyDADMAC) and silica particles, followed by a fluorination surface treatment with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS, CF3(CF2)5CH2CH2Si(OC2H5)3). The wood fiber products prepared in this study had contact angles of water greater than 150 degree and sliding angles less than 5 degree. Besides their high water repelling property, the superhydrophobic paper products kept a high tensile strength at high relative humidity condition. The superhydrophobic paper products also showed high resistance to bacterial contamination.

The dissolution profile of orally delivered drugs can be controlled through the use of osmotically controlled drug delivery devices. The most commonly used device is the osmotic tablet, which is essentially a tablet core that is coated with a rate-limiting semipermeable membrane. The feasibility of applying a coating onto a tablet using dense gas techniques was studied. Two different coating materials, polymethymethacrylate (PMMA, Mw = 120,000 g/mol) and cellulose acetate (CA, 39.8 wt% acetyl content) were applied onto an 8 mm osmotic tablet core using the Gas Anti-solvent (GAS) process. For PMMA, the pressurisation rate, coating temperature and volumetric expansion of up to 250% had minimal effect on the coating quality. The concentration, solvent type and the use of polyethylene glycol (Mw = 200 g/mol) had a more pronounced effect on the coating. The coating process was optimised to apply a smooth and uniform coating with a 50 ??m thickness. For CA, the pressurisation rate and the coating temperature had little effect on the coating that was applied. The process was more sensitive to a change in the concentration of the solution and the volumetric expansion that was used. It was found that the concentration could not be increased too much without affecting the coating quality. A CA coating was applied onto a PMMA-coated tablet using the optimised conditions. The thickness in the tablet coating increased by 10 ??m. Dissolution tests of the uncoated and coated tablets were carried out. The CA coatings were found to be insufficient in limiting the rate of water entering the tablet and performed similarly to an uncoated tablet core. The PMMA coatings were found to limit the rate of delivery of the model drug. However, variations in the PMMA coatings resulted in an inconsistent delivery profile across batches. The tablets coated with both PMMA and CA had a delivery rate in between that of uncoated and PMMA-coated tablets, indicating that the application of the second coating had compromised the initial PMMA coating.

Surfaces submerged in marine environments rapidly get colonized by marine organisms, a process known as biofouling. Fouling costs maritime industries billions of dollars annually. The most common methods of combating marine biofouling are toxin containing antifouling coatings which often have detrimental non-target environmental effects. These effects and proposed bans on harmful substances in antifouling coatings, mandates development of more environmentally friendly antifouling technologies. Of these, foul-release coatings, which minimize attachment and adhesion of fouling organisms (rather than killing them) are promising alternatives. Here I explored the utility of petroleum waxes as novel antifouling/foul-release coatings. I first investigated the responses of propagules (larvae or spores) of six common fouling organisms to wax coatings in the laboratory. A wide variation in the response of these different organisms, and in the different types of response (settlement, adhesion, etc.) by the same organism, was observed, but the most inhibitory coatings were those made from microcrystalline wax and silicone oil. However, in field trials in Sydney Harbour, paraffin waxes had the strongest antifouling performance, with activity up to one year (the trial duration). These waxes also had strong foul-release effects, with fouling that did attach mostly removed by a low pressure water jet. Composition of fouling communities on paraffin waxes differed significantly from other waxes or controls, with little or no hard fouling organisms (barnacles, bivalves) on paraffin. The mechanisms of antifouling and foul-release actions of paraffin waxes appear to be due to changes in surface properties. The surfaces of the paraffin waxes changed noticeably after 4 - 8 weeks immersion in the sea or in seawater aquaria. Antibiotic treatments showed that this change in surface appearance was due to biological (microbial) activity. Bacteria appear to remove the amorphous phase from the surface of the paraffin waxes, revealing an underlying crystalline phase, which is less affected by bacterial action. I suggest that these crystals form a microstructured ?bed of nails? of crystals of varying shapes and sizes which inhibit settlement and reduce adhesion strength of those organisms which do settle.

Thesis (Ph.D.)--University of Tulsa, 1993. / Includes bibliographies.

Thesis (M.S. in mechanical engineering)--Washington State University, May 2008. / Includes bibliographical references (p. 54-55).

Thesis (Ph.D.)--University of Western Sydney, Nepean, 1995. / Bibliography: leaves [214]-227.

Thesis (M.S.)--Rochester Institute of Technology, 1991. / Typescript. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 245-251).

Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. "November 13, 1998." Document formatted into pages; contains x, 121 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 105-110).