This thesis presents the design and experimental evaluation of an in-line, active ultrasound, condition monitoring setup for the detection of contamination in offshore bearing grease. This process is divided into three distinct research steps. First of all, the influences that affect ultrasound propagation through a bearing grease sample have been investigated through various laboratory experiments. Next, a practical, real-world experiment using a linear bearing has been designed and conducted with the aim of determining the applicability of such an in-line condition monitoring setup. Lastly, the performance of the in-line active ultrasound setup has been evaluated, improvements have been proposed and an overall condition monitoring strategy has been devised.

During the laboratory experiments, various influences on ultrasound wave propagation have been investigated. First of all, design-specific parameters, such as the distance between the sensors, the test-setup material, and the scalability of the measured output voltage have been investigated. Next, the effects of temperature fluctuations, air bubble fluctuations, water contamination and iron particle contamination on the attenuation and velocity of waves for active ultrasound spectroscopy were investigated. It has been shown that air bubble concentration and temperature fluctuations influence the attenuation of the ultrasound in the grease sample. Therefore, the temperature should be kept constant throughout the other experiments. Additionally, the air bubble concentration should be managed through a constant resting time throughout the other experiments. Moreover, it has been shown that a condition monitoring setup employing active ultrasound spectroscopy is able to determine water contamination and iron particle contamination. The highest sensitivity of this contamination detection is located in the first percentage of contamination concentration, showing an amplitude drop of about 0.5dB/mm to 1dB/mm and a change in speed of sound of about 5\% to 15\%. It is however, difficult to differentiate between the different types of contamination using only the attenuation and velocity spectroscopy methods.

The practical, real-world experiment using an operational Huisman linear bearing has illustrated the applicability of using an in-line grease condition monitoring setup in such an environment, by evaluating obstacles such as spatial constraints, location constraints, flowability of the grease and surrounding noise. It has been shown that these obstacles pose minimal challenges for the successful implementation of an in-line grease monitoring setup for effective condition monitoring of offshore bearing grease.

The evaluation of the improved in-line active ultrasound condition monitoring setup has highlighted the strengths and weaknesses of implementing such a setup for offshore applications. A possible combination of the proposed grease condition monitoring method with Acoustic Emission monitoring offers

Throughout this literature research report, the influence of operational conditions during bulk storage on the mechanical characteristics of various inorganic, crystalline, day-to-day salts has been investigated, in order to make a prediction on the effect of operational conditions on the mechanical characteristics of sodium borohydride. Firstly, an analysis and selection of the various mechanical characteristics has been conducted. Secondly, an analysis of the chemical properties helped to select a list of materials that are chemically similar to sodium borohydride. Thirdly, an effort was made to compare these materials to sodium borohydride using the selected mechanical characteristics. Using the particle sizes, bulk densities and angles of repose, sodium borohydride could to a certain extent be linked to calcium chloride, magnesium sulfate, potassium chloride, potassium carbonate and silicon dioxide. Lastly, an analysis on the effect of operational conditions on the mechanical characteristics of the materials has been conducted. No definitive conclusions could be drawn about the effect of the operational conditions on the mechanical characteristics of sodium borohydride.