The thesis outlines the usual parametric analysis of field failure time data for repairable equipments. Due to shortcomings of this black-box approach, exploratory reliability analysis has been adopted to exploit the available data and so learn more about the physical failure process. Elements of exploratory analysis have appeared in recent statistical applications of point process, time series and multivariate methods in the area. These approaches are reviewed and investigated. Exploratory analysis of much field time between failure and limited repair time data for hardware equipments has been undertaken. Despite being from different physical mechanisms, software failure interval data has the same underlying statistical point process as such hardware data and has been similarly investigated. Simple graphs, often with simulation bounds, inference procedures for nonhomogeneous Poisson processes and Box-Jenkins analysis have been used to search for and model aspects of structure expected in reliability data. The appropriateness of the methods is discussed. As well as revealing that (constant) failure rates are often unsuitable summaries, exploratory analysis has highlighted features previously unknown or ignored. The identified time structures, data irregularities and other complexities are described. Exploratory analysis indicated potential dependent failures. A simulation-based graphical tool for highlighting these important events is described. Applications to real data have shown this is a promising approach. Principal coordinates and cluster analyses have been used to explore multivariate field data for automatic fire detection systems in an attempt to identify circumstances leading to false alarms. Data problems limited this analysis. Exploratory analysis has revealed it is common in reliability to assume a too simplistic model formulation compared with the true complex data structures. The implications of this for reliability data collection. storage and analysis are discussed. While an exploratory approach is generally successful, some specialisation of standard statistical methods for reliability is desirable.

<p> Thin films (~100 nm) have been prepared of the prototypical spin-crossover complex Fe(phen)₂(NCS)₂ (phen = 1,10-phenanthroline). Initial attempts to prepare these films by direct vapor deposition yielded films of a different material. Through extensive FT-IR, Raman, UV-Vis, and x-ray photoelectron spectroscopy it is shown that these as-deposited films are the ferroin-based tris complex [Fe(phen)₃](SCN)₂. Structural characterization by AFM and powder XRD reveals them to be smooth and amorphous. When heated, the [Fe(phen)₃](SCN)₂ films are converted first to Fe(phen)₂(SCN)₂ and then to a third species postulated to be Fe(phen)(NCS)₂ which is likely a one-dimensional coordination polymer. On the other hand, deposition from Fe(phen)₂(NCS)₂ onto heated substrates produces a mixture of these three materials. The identity of the Fe(phen)₂(NCS)₂ films is proved by additional spectroscopic, structural, and magnetic characterization. Magnetometry reveals them to remain spin-crossover active albeit with a more gradual and incomplete spin-transition than the bulk material. The films are found to be granular in nature and deep crevices were observed at the grain boundaries. Within the optical microscope, the coloring of the grains is seen to be dependent upon sample orientation. Powder XRD indicates texturing of crystalline domains where the crystallographic c-axis is parallel to the surface normal. This represents a new process for production of Fe(phen)₂(NCS)₂ films.</p><p> With the aim of realizing the potential for spin-crossover materials to modulate electrical conduction and vise versa, electrical characterization has been performed as a function of temperature on vertical junction devices incorporating the prepared Fe(phen)₂(NCS)₂ films. In order to prevent penetration of the top electrode through the cracks and crevices in the organometallic layer, a multiple sequential deposition and annealing process was developed to produce films with a continuous surface topography. A small change in the weak electrical conductivity of these devices appears at the spin transition temperature, demonstrating for the first time in this important material a coupling of the electrical conductivity and magnetic spin state. Here, the HS state has a higher electrical conductivity. Incorporation of LiF interfacial layers between the Fe(phen)₂(NCS)₂ and the metal electrodes improves conduction slightly but tunneling still appears to be the current-limiting mechanism. Electrical measurements were also performed on devices made with the related complex [Fe(phen)₃](SCN)₂. Such films were much more conductive&mdash;as good as other typical organic semiconductor materials. All together, this work establishes the potential for this family of complexes to be incorporated into thin-film based electrical devices whose operation is based on the spin-crossover effect or otherwise.</p>

<p>Research concerning lignin has increased during the last years due to its renewability and ready availability in black liquor at pulp mills. Today, the kraft lignin found in black liquor is used as a fuel to gain energy in the recovery boiler at the mill. However, a new isolation concept, LignoBoost®, has enabled isolation of part of the lignin while allowing the use of black liquor as a fuel. This isolated lignin can be utilised as a fuel in, for example, thermal power stations or further upgraded to more value-added products. In this context, the most interesting value-added product is carbon fibre. The demand for carbon fibre has increased, but the biggest obstacle for a more extended use is the high production cost. About half of the production cost is related to the raw material.</p><p>In this work, the possibility of using kraft lignin as a precursor for carbon fibre production has been investigated through fundamental studies. Kraft lignins originating from birch, <em>Eucalyptus globulus</em>, softwoods and softwoods from liner production have been studied. By separating the lignin while still in solution in the black liquor, unwanted large particles such as carbohydrates can easily be removed. After isolation according to the LignoBoost process and purification with the use of an ion-exchanger, the lignins have been both chemically and thermally characterised. Identification of the released compounds at different temperatures has been performed because only 40% of carbon relative to original lignin remains, down from theoretical 60% after thermal treatment up to 1000°C. The main released compounds were phenols, as revealed by pyrolysis-GC/MS. Additionally, a pre-oxidation was done in order to try to stabilise the lignins. It was shown that an oxidation prior to the thermal treatment increases the yield by more than 10% and that the main release of compounds takes place between 400°C and 600°C. Fractionated lignin is better qualified as raw material for carbon fibre production because it is purer and its softening temperature can be detected. Fractionated kraft lignins from all investigated wood sources have high possibilities to act as precursors for the manufacture of carbon fibre.</p>

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It is the purpose of this thesis to explore the feasibility of using coated-wire electrodes to measure chelating agent concentration. Chelating agents are often found in radioactive decontamination solutions because they aid in the removal of radionuclides from contaminated surfaces by increasing their solubility. However, this characteristic will also enhance the mobility of the radionuclide and thus its transport out of a waste disposal site. Coated-wire ion selective electrodes, based on a polyvinylchloride membrane using dioctylphthalate as a plasticizer and dinonylnaphthalene-sulfonic acid as a counterion, were constructed for five commonly utilized chelating agents (ethylenediaminetetracetic acid (EDTA), nitrilotriacetic acid (NTA), citric acid, oxalic acid and tartaric acid). The EDTA and NTA electrodes' calibration characteristics exhibited acceptable behavior in pure standard solutions. From data obtained while using the EDTA and NTA electrodes in a cement environment, further research needs to be done in the area of ion interference.

The role of modifier on the molecular structure of Ca-phosphate, sodium fluorophosphate and sodium aluminophosphate glasses have been investigated by Raman spectroscopy. Ca-phosphate glasses for this study have the molar ratio of CaO/P₂O₅ from 1.00 to 1.50. Curve fitting procedures have been used to resolve the overlapped peaks for accurate interpretation. Amorphous species with varying chain lengths and two crystalline phases of γ- and α-Ca₂P₂O₇ have been identified. Sodium fluorophosphate glasses have been prepared from the reaction between Al(PO₃)₃ and NaF. The molar ratio of Na/P is varied from 0.900 to 2.00 and the F/P ratio is from 0.510 to 1.61. By studying the vibrational frequency shifts, species with varying phosphorus and fluorine contents and aluminophosphate compounds have been identified.