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Influences of grain boundaries and surface nanocrystallization of stainless Steel on Pseudomonas Aeruginosa Biofilms AdherenceYu, Bin 06 1900 (has links)
A common complication associated with medical implants is the infectious bio-film, which can cause chronic infection that is difficult to control. Grain boundaries (GBs) in materials of medical implants are often preferential locations for bacteria to congregate, which could be attributed to higher affinity of grain boundaries for bacterial bio-films. In this study, the molecular interaction of the Pseudomonas aeruginosa receptor binding domain, a self-folding domain of 17 amino acid residues derived for the PilA structural protein, which can represents properties of Pseudomonas aerginosa biofilm, with microcrystalline stainless steel surfaces was examined with atomic force microscopy (AFM) both at grain boundaries and within grains. Adherence of Pseudomonas aeruginosa biofilm to nanocrystallized stainless steel surface was also determined using AFM. Results indicate that adherence of biofilm adherence at grain boundaries of microcrystalline surface is 2-fold higher than that of inside grains. Nanocrytalline surface is more resistant to biofilm than the microcrystalline one due to the formation of a strong oxidation film after annealing and thermal oxidation process. Surface nanocrystallization for enhanced corrosion resistance of Ag-incorporated 304 stainless steel surface was also studied. It is demontstrated that nanocrystallization of the antibacterial agent-incorporated stainless steel surface also provides an effective approach to control the corrosion problem resulting from the typical galvanic effect of multiphase alloys.
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Investigation of monolayer interactions by wave attenuation and surface pressure studiesAḥmad, Jamīl January 1969 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii, 1969. / Bibliography: leaves [86]-87. / vii, 87 l illus
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Particle interactions, surface chemistry and dewatering behaviour of gibbsite dispersions /Bal, Heramb. Unknown Date (has links)
In this research project gibbsite is taken as a model for understanding and improving dewatering behaviour. The main aim of this study was to investigate primary process variables such as polymer functionality, charge type/density and molecular weight, pH and shear influence interfacial chemistry and particle interactions and the concomitant dewatering behaviour of gibbsite dispersions. In addition the study explored how using these variables, pulp dewaterability might be optimized. / Thesis (MEngineering)--University of South Australia, 2006.
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Orthokinetic flocculation, optimized particle interactions and dewatering of clay mineral dispersions /McFarlane, Angus. J. Unknown Date (has links)
The main aim of this study was to investigate how primary process variables such as clay mineral type, polymer functionality, agitation intensity and temperature influence flocculant-mediated interfacial chemistry and particle interactions and the concomitant dewatering behaviour of colloidally stable clay dispersions. It is also an arching aim to explore how using these variables, pulp detwaterability might be optimised. / Thesis (PhDApSc(MineralsandMaterials))--University of South Australia, 2006.
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The influence of adsorbing polymers on solid surface wettability /Kaggwa, Gillian. Unknown Date (has links)
The broad aim of this research study was to investigate the influence of adsorbing polymers on surface wettability. In particular, the relationship between the properties of the adsorbed polymer layer (the adsorbed amount, layer thickness and morphology) and the surface wettability was elucidated. / Thesis (PhDApSc(MineralsandMaterials))--University of South Australia, 2005.
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An analysis of mesoporous structure in controlled porosity solids /Fusco, Lina. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 1997
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Thymine-functionalized gold nanoparticles : synthesis, surface structure and colloid stabilityZhou, Jingfang January 2008 (has links)
Monolayer protected nanoparticles (MPNs) display fascinating size-dependent electronic, optical and catalytic properties. They are promising candidates to be used as building blocks with which to construct new generation nanoarchitectures and nanodevices for sensing, electronic and optoelectronic applications. The aggregation and dispersion of colloidal nanoparticles is one of the key issues closely related to their potential applications. Our knowledge of the colloid stability of nanoparticle dispersions with small sizes is still in its infancy, however, thymine is one of the bases in DNA, and is a pH sensitive and chromatic molecule. In the present study, thymine-functionalized self-assembled monolayer protected gold nanoparticles were synthesized. Their morphology and surface structure were characterized using TEM, UV-vis, FTIR, DSC-TGA and XPS techniques. The colloid stability of thymine-capped gold nanoparticle dispersions as a function of the type and concentration of monovalent salt, pH and particle size in alkaline aqueous solution were investigated. The manipulation of colloid stability with light was further explored. The results and conclusions are summarized inthis thesis.
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Synthesis and calcification of hydrogel biomaterialsZainuddin, Z. Unknown Date (has links)
No description available.
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Application of surface science to sulfide mineral processingGoh, Siew Wei, Chemistry, Faculty of Science, UNSW January 2006 (has links)
Surface spectroscopic techniques have been applied to facets of the flotation beneficiation and hydrometallurgical extraction of sulfide minerals to enhance the fundamental understanding of these industrially important processes. As a precursor to the determination of surface chemical composition, the sub-surface properties of some sulfide minerals that have not previously been fully characterised were also investigated. The electronic properties of ??-NiS and ??-NiS (millerite), Ni3S2 (heazlewoodite), (Ni,Fe)9S8 (pentlandite), CuFe2S3 (cubanite), CuFeS2 (chalcopyrite), Cu5FeS4 (bornite) and CuS (covellite) were investigated by conventional and synchrotron X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy augmented by ab initio density of state calculations and NEXAFS spectral simulations. Particular aspects studied included the relationship between sulfur coordination number and core electron binding energies, the higher than expected core electron binding energies for the sulfur in the metal-excess nickel sulfides, and the formal oxidation states of the Cu and Fe in Cu-Fe sulfides. It was concluded that the binding energy dependence on coordination number was less than previously believed, that Ni-Ni bonding was the most likely explanation for the unusual properties of the Ni sulfides, and that there was no convincing evidence for Cu(II) in sulfides as had been claimed. Most of the NEXAFS spectra simulated by the FEFF8 and WIEN2k ab initio codes agreed well with experimental spectra, and the calculated densities of states were useful in rationalising the observed properties. XPS, static secondary ion mass spectrometry (SIMS) and NEXAFS spectroscopy were used to investigate thiol flotation collector adsorption on several sulfides in order to determine the way in which the collector chemisorbs to the mineral surface, to differentiate monolayer from multilayer coverage, and to characterise the multilayer species. It was found that static SIMS alone was able to differentiate monolayer from multilayer coverage, and together with angle-resolved NEXAFS spectroscopy, was also able to confirm that 2-mercaptobenzothiazole interacted through both its N and exocyclic S atoms. The altered layers formed on chalcopyrite and heazlewoodite during acid leaching were examined primarily by means of threshold S KLL Auger electron spectroscopy, but no evidence for buried interfacial species was obtained.
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Coded one-port acoustic surface-wave delay lines / by A.S. BurgessBurgess, Alan Stanley January 1974 (has links)
x, 270 leaves, : ill., tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical Engineering, 1975
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