This thesis explores the application of an advanced on line measurement technique in the control of a chemical process. The research explores emulsion fonnulation in an Oscillatory Baffied Reactor (OBR) by measurement using Electrical Impedance Tomography (EIT) technique. The research demonstrates new tools allowing emulsification methods for the precision manufacture of emulsions in the OBR through advanced online monitoring instrumentation. Experimental work demonstrated the production of water-in-oilJoil-in-water emulsions whilst simultaneously monitoring the process in the OBR using EIT. The development of a non intrusive method to visualise the evolution of the emulsion in the OBR using EIT is described. Experimental work demonstrated the capability to relate quantitatively the data obtained from the EIT measurement with . . the characteristic flow pattern in the OBR and the degree ofmixing of the emulsion. The use of cross correlation method is discussed to obtain average velocity profiles of the flow in applications using EIT as a measurement technique. A CFD simulation of the process was developed to compare~and validate the results from the . EIT measurement and the cross correlation application. The results indicated a good agreement between the results obtained from the different methods was achieved. The analysis of the distribution of droplet size in the OBR was carried out. The decreasing evolution of the droplet size and the standard deviation of droplets in the OBR were modelled. The results of the fitted correlation' demonstrated a precise fitting ofthe experimental values (R2= 0.8865 in the worst case). A statistical method is applied to reduce and select the most relevant data from the EIT measurement. The application of principal component analysis (PCA) to the EIT data demonstrated the capability to represent accurately 90% of the variability of the conductivity values of316 pixels with only 10 values (principal components). A neural network was developed using the data obtained from the PCA as input. The simulation of a feed forward neural network based on the PCA in order to obtain the coefficient of variance (CV) of the droplet size distribution showed good results. The average error found for the simulated average droplet size was less than 10%. This guaranteed a good level of accuracy and robustness of the neural network developed. . The research in this thesis demonstrates successfully a novel methodology of advanced on line measurement and analysis of the characteristics of an emulsion in the OBR. This research facilitates the formulation and monitoring of new emulsion products in the OBR and its statistical analysis on a continuous basis using EIT. The methods developed could have applications for monitoring the production of other and more complex multiphase formulations, using semi-continuous reactors.

This thesis is entitled 'Molecular Logic Gates Bound To Solids' and is separated into five chapters. The first chapter introduces logic gates and the potential applications of molecular logic gates. Photochemical mechanisms, Photoinduced electron transfer (pET) and Internal charge transfer (lCT), through which many sensors and molecular logic gates operate are focused upon. It also reveals how the application of chemical or optical inputs and optical outputs from molecules, with the aid ofthe PET and ICT mechanisms can construct molecular logic gates. Chapter 2 presents molecular logic gates which are prefabricated and covalently bound onto organic and inorganic beads. The YES and PASS 1 operations are displayed both individually and in parallel and are driven by proton inputs. Chapter 3 entails the introduction ofternary logic with the 'off-on-off' logic gate. Its . operation in solution is transcended when covalently attached onto a solid platform and is driven by proton inputs. Chapter 4 involves the discussion of double-input logic gates. The AND gate which is solid-bound is driven by protori and sodium ion inputs. Chapter 5 demonstrates how selectivity· of logic gates govern their operation. The YES and OR molecular logic gates are performed on the organic and inorganic beads through calcium and zinc ions. Chapter 6 presents analytical data and experimental procedures for all molecules included in Chapters 2, 3, 4 and 5. IV

Column runs with varied operation conditions of flowrate, feed concentration and particle size have been conducted to observe the sorption of nickel, copper and zinc by the chelating resin. They all show a typical constant-pattern, steep curve in the first part of the breakthrough curve and the slope would dramatically reduce at a breakpoint such that it would take extremely long time to reach 100% breakthrough level. ~ The Modified Bed Depth Service Time (BDST) model incorporated with a timedependent bed capacity has been used together with the Empty Bed Residence Time (EBRT) model to analyze the fixed bed performance under different operating conditions. The Homogeneous Surface Diffusion Model (HSDM) and the Shrinking Core Diffusion . Model (SCDM) have been applied to- model the fixed bed performance. Due to the dramatic change in the slope, the first and second parts of the breakthrough curves need to be modeled separately. Comparing the two models, SCDM is more appropriate to explain the sorption of metal ions into the chelating resin. The research has suggested the existence of a Na-loaded outer shell and a H-loaded inner core in the chelating resin. When the moving boundary progresses from the outer shell into the inner core, there is a remarkable change in the ion exchange process, resulting in different kinetics. This explains the sharp change in the slope of the experimental breakthrough curves. A new version of SCDM has been developed to model the progression of the moving boundary inside the resin for the successive resin layers along the whole resin column so as to predict the column' s solid and liquid phase concentration profiles. The new SCDM has. the flexibility of varying the portion of the outer shell so that the behavior of resins with different resin Na contents can be predicted.

This thesis will address the use of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques to probe the 'monolith reactor', which consists of a structured catalyst over which reactions may occur. This reactor has emerged as a potential alternative to more traditional chemical engineering systems such as trickle bed and slurry reactors. However, being a relatively new design, its associated flow phenomena and design procedures are not rigorously understood, which is retarding its acceptance in industry. Traditional observations are unable to provide the necessary information for design since the systems are opaque and dynamic. Therefore, NMR is proposed as an ideal tool to probe these systems in detail. The theory of NMR is summarised and the development of novel NMR techniques is presented. Novel techniques are validated in simple systems, and tested in more complex systems to ascertain their quantitative nature, and to find their limitations. These techniques are improvements over existing techniques in that they either decrease the acquisition time (allowing the observation of dynamically-changing systems) or allow us to probe systems in different ways to extract useful information. The goal of this research is to better understand the flow phenomena present in such systems, and to use this information to design better, more efficient, more controllable industrial reactors. The analysis of the NMR data acquired is discussed in detail, and several novel image-processing techniques have been developed to aid in the quantification of features within the images, and also to measure quantities such as holdup and velocity. These novel techniques are validated, and then applied to the systems of interest. Various configurations of monolith reactor, ranging from low flow rate systems to more challenging (and more industrially relevant) turbulent systems, are probed using these methods, and the contrasting flow phenomena and performance of these systems are discussed, with a view to optimisation of the choice of design parameters.

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