Corrosion Detection: A Fibre Optic Approach

Corrosion is a multi-billion dollar problem faced by industry. High acquisition costs associated with modern military and civilian aircraft coupled with tighter budgets has resulted in the need for greater utilisation of existing aircraft eets. With advancing aircraft age there is increased possibility that protective coatings will break down or be damaged, resulting in exposure of the base material to the environment and an increased possibility of corrosion. Corrosion is most difficult to detect in inaccessible metallic structures within aircraft. Monitoring these areas requires a sensor capable of spatially resolved detection of corrosion (distributed measurements), so that the location of the detected corrosion can be determined. Optical fibre based sensors are inherently suited to distributed sensing and are typically in the order of only a few hundred microns in diameter making them very lightweight and suitable for embedding in otherwise inaccessible corrosion-prone areas. This thesis describes the development of an optical fibre based corrosion sensing element. Transition of exposed-core microstructured optical fibres from soft glass to silica is shown to provide a platform for optical fibre sensors requiring long term and/or harsh environmental applications while providing real time analysis anywhere along the fibres length. The portion of light guided outside of the glass core, often described as the `evanescent field,' is affected by the refractive index and absorption characteristics of the surrounding medium. Functionalising this core with chemosensors sensitive to corrosion by-products, turns the light guiding fibre into a corrosion sensing element, with which insitu kinetic measurements of accelerated corrosion in simulated aluminium aircraft joints is demonstrated. This provides a fibre optic approach for detection of corrosion inside the hidden part of structures and opens up new opportunities for distributed optical fibre chemical sensing with a capacity for long-term application in harsh environments.Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 201

Swelling of biocompatible polymer films.

The incorporation of drugs into phosphorylcholine (PC) polymers coated onto coronary stent surfaces is one potential method of treatment for reducing restenosis, the reclosure of the artery after angioplasty treatment. This work on the characterisation of the swelling performance of thin PC polymer films represents a further extension of the study on biocompatible polymers. The broad aim of this work is to relate the PC polymer structure and film processing conditions to their swelling, drug loading and release kinetics. As the two highly sensitive and powerful techniques in film structure determination, both ellipsometry and neutron reflection have proved to be useful in characterising PC polymer films and drug release processes. Following an established ellipsometry measurement method, a two stage process consisting of diffusion and relaxation has been observed during the PC film swelling: this suggests an anomalous mechanism, and this performance is well described by the coupled diffusion and relaxation model developed by Berens and Hopfenberg. Furthermore, the swelling of PC polymer films was investigated as a function of cross-linking, annealing temperature, chemical composition, hydrophilic/hydrophobic ratios, film thickness and environmental conditions by ellipsometry measurements, and their effects on swelling kinetics well quantified. The structures of the PC polymer films (PC100B) with cross-linking groups have been further characterised by neutron reflection. The segregation of hydrophobic and hydrophilic domains was found in the PC films with different dimensions. The PC100B with deuterated dodecyl chains was used to highlight the interfacial structures of the PC films. The hydrophilic segments, including phosphorylcholine groups and hydroxypropyl groups, are preferentially adsorbed at the polymer/substrate interface. The hydrophobic dodecyl chains are expelled away from the silicon oxide surface. The main part of PC100B films is the middle uniform region with 40% of water in the sample annealed at 150°C, and 55% of water in the sample annealed at 50°C. The combination of the ellipsometry results and the drug release profiles from UV measurements indicates that the drug release pattern is strongly affected by the film swelling kinetics when the drug molecules and polymer matrix interact weakly. Otherwise, a strong interaction between the drug and the polymer will dominate the drug release behaviour from the PC polymer films

Independence of Misdemeanour Jury and its Members

L'article discute de principe de l'indépendance du collège pour les affaires des contraventions. Ce principe signifie une libération de l'organe rendant une décision de l'influence de quelconques facteurs extérieurs dirigeant au tranchement non objectif de l'affaire. Quant au collège cela s'exprime en général par la particularité organisationnelle envers des organes d'Etat. Dans le cas du membre du collège pour les affaires des contraventions cela constiste à l'exercice de la fonction de décider étant soumis seulement à la norme juridique et à sa conviction intérieure. Ce sont les éléments suivants qui décident de l'indépendance du membre du Collège pour les affaires des contraventions: 1) l'obéissance seulement à la loi, 2) l'indépendance du trancheiment, 3) l'omission en rendant une décision de tous les égards et influences casuelles, 4) le soulignement de la responsabilité exclusive de la décision donnée. Dans cet article on discute aussi des garanties de l'indépendance. Les garanties de l'indépendance du collège comme un ensemble c'est surtout la distinction d'organisation et le caractère de l'instance. Dans ce domaine on a discuté l'influence des organes de l'autorité et de l'administration sur la position du collège et on a fait remarquer la possibilité de l'atteinte contre l'indépendance. Voici les garanties de l'indépendance concernant le membre du collège: le niveau élevé moral et éthique, des qualifications convenables, le caractère social de cette fonction, la protection du rapport de travail, l'égalisation quant à la protection juridique avec le fonctionnaire d'Etat. Outre des garanties de régime il existe aussi de certaines exigences de procès de l'indépendance. On a classé parmi elles la collégialité de rendre des décisions, la publicité de la procédure, une libre appréciation des preuves et le secret de la délibération. L'article souligne aussi, qu'on ne peut pas parler sur l'indépendance seulement sur le fondement des dispositions. Car elles ne créent que des conditions à la réalisation de ce principe en pratique.Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

Independence of Misdemeanour Jury and its Members

L'article discute de principe de l'indépendance du collège pour les affaires des contraventions. Ce principe signifie une libération de l'organe rendant une décision de l'influence de quelconques facteurs extérieurs dirigeant au tranchement non objectif de l'affaire. Quant au collège cela s'exprime en général par la particularité organisationnelle envers des organes d'Etat. Dans le cas du membre du collège pour les affaires des contraventions cela constiste à l'exercice de la fonction de décider étant soumis seulement à la norme juridique et à sa conviction intérieure. Ce sont les éléments suivants qui décident de l'indépendance du membre du Collège pour les affaires des contraventions: 1) l'obéissance seulement à la loi, 2) l'indépendance du trancheiment, 3) l'omission en rendant une décision de tous les égards et influences casuelles, 4) le soulignement de la responsabilité exclusive de la décision donnée. Dans cet article on discute aussi des garanties de l'indépendance. Les garanties de l'indépendance du collège comme un ensemble c'est surtout la distinction d'organisation et le caractère de l'instance. Dans ce domaine on a discuté l'influence des organes de l'autorité et de l'administration sur la position du collège et on a fait remarquer la possibilité de l'atteinte contre l'indépendance. Voici les garanties de l'indépendance concernant le membre du collège: le niveau élevé moral et éthique, des qualifications convenables, le caractère social de cette fonction, la protection du rapport de travail, l'égalisation quant à la protection juridique avec le fonctionnaire d'Etat. Outre des garanties de régime il existe aussi de certaines exigences de procès de l'indépendance. On a classé parmi elles la collégialité de rendre des décisions, la publicité de la procédure, une libre appréciation des preuves et le secret de la délibération. L'article souligne aussi, qu'on ne peut pas parler sur l'indépendance seulement sur le fondement des dispositions. Car elles ne créent que des conditions à la réalisation de ce principe en pratique.Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201

Spark Plasma Sintering of Variable SiC α/β Ratio with Boron and Carbon Additions—Microstructure Transformation

This study investigated the possibility of obtaining dense silicon carbide sinters with the use of a spark plasma sintering (SPS) process by changing the composition of SiC α/β polymorphs in a starting powder mixture. Amorphous boron was used as the basic additive to activate the sintering processes. Some of the compositions were prepared with additional carbon in two different forms: multilayer graphene flakes and carbon black. The well-described effect of the β–α transition in the form of elongated lamellar grains in the sintered structure was confirmed. The obtained sinters were analyzed qualitatively and quantitatively in terms of the microstructure and density. The hardness and the participation of the polytypes in the sinter structures were examined. During the study, SPS sintering allowed us to obtain a material with a density close to the theoretical (relative density of 99.5% and hardness of 27 MPa) without the addition of carbon. It was found that the role of carbon was not limited to the activation of the sintering process. Additional effects accompanying its presence, depending on the initial α/β composition, included grain size reduction and an influence on the transformation kinetics

Measurements of Strain in Ceramic Components Using Magnetostrictive Delay Line

score: 0collation: 29-3

Artificial quantum photosynthetic materials

Photosynthesis has been shown to be a highly efficient process for energy transfer in plants and bacteria. It has been proposed that quantum mechanics plays a key role in this energy transfer process. There has been evidence that photosynthetic systems may exhibit quantum coherence. As artificial light-harvesting complexes have been proposed to mimic photosynthesis, it is prudent that artificial photosynthetic materials should also be tested for quantum coherence. To date, such studies have not been reported. In this work, we examine one such system, the BODIPY light harvesting complex (LHC), which has been shown to exhibit classical energy transfer via Förster resonance energy transfer. We compare the photon absorption of the LHC with the BODIPY chromophore by performing UV-visible, transient absorption, broadband pump-probe (BBPP) and two-dimensional electronic (2DES) spectroscopy. The 2DES and BBPP show evidence for quantum coherence, with oscillation frequencies of 100 cm-1 and 600 cm-1, which are attributable to vibronic, or exciton-phonon type coupling. Further computational analysis suggests strong couplings of the molecular orbitals of the LHC resulting from the stacking of neighbouring BODIPY chromophore units may contribute to undesirable hypochromic effects