Reliability engineering... My first two years with Babcock on the graduate sceheme has seen me working with the MoD (specifically the SDA) in Abbey Wood, writing automated test scripts in Python, working on interesting facility designs, and taking trips inside of submarines. In autumn of 2020 I'll start a role as a safety engineer, hopefully specialising in Probabilistic Safety Assessment.
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Thermal separation of crude oils... Since finishing my PhD in December 2016, I undertook various non-contractual roles within the university, which included research, demonstrating/teaching to all stages of the BSc (Hons) chemistry course, STEM outreach, laboratory management (ISO 9001 documentation), and conducting consultancy work. The consultancy work was on an ad hoc basis through the UoPEL (University of Plymouth Enterprise Ltd) Commercial Consultancy and Contract Research department for a small company called Kernow Analytical Technology (KAT) within the Petroleum and Environmental Geochemistry Group (PEGG), in which the separation, using a novel method known as T-SEP, and subsequent analysis of various oils for its wax content were performed. T-SEP is a proprietary, small scale, thermal separation technique that has been developed by KAT in partnership with the University of Plymouth, and concentrates the >nC20 fraction of the oil in order for better and more accurate analysis of the heavier n-alkanes using high temperature gas chromatograph (HTGC) coupled with mass spectrometry.
n-Paraffin weight distributions with and without T-SEP enhanced sample preparation.
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Nanoporous calcium carbonate-based substrates for controlled delivery of functional materials (2016)
The aim of this ‘high-risk’ project, in collaboration with Omya International AG (a leading producer of calcium carbonate derived minerals), was to study functionalised calcium carbonates (FCCs) as active substrates for the controlled delivery of functional materials.
FCCs are highly porous, highly absorptive (mainly for charged species), have a high surface area, and have a wide range of sizes and morphologies; they currently have great application as fillers and pigments in paper-coating, paints, and plastics. FCCs are made from particles of calcium carbonate that have been acid-etched to make them dual porous. Dual porosity includes inter-particle pores (i.e. the pores between particles) and intra-particle pores (i.e. the pores within particles), which can be characterised using mercury intrusion porosimetry.
The overall aim of my doctoral research project was to find new applications for FCCs through the study and development of these MCCs as active substrates for the slow delivery of functional materials, and is in collaboration with Omya AG (headquarters based in Oftringen, Switzerland).
My thesis initially presents the investigation of the way in which FCC adsorbs various compounds, followed by the attempted scanning electron microscopy characterisation of FCC pores loaded with flavour. The next chapter used Python to model diffusion data from the Science Partner Technical Research Institute of Sweden before discussing zero length and finite length cell work.
A ‘zero-length’ cell (ZLC) is a device invented by Ruthven et al. (1988), and further developed within the Environmental and Fluid Modelling Group (EFMG) at Plymouth using organic solvents. It is comprised of two sinters between which a mono-layer of porous material is sandwiched. The whole device is connected to a High Performance Liquid Chromatography (HPLC) unit, and allows the precise study of the diffusion characteristics from the material.
In order to obtain more varied measurements, the ZLC has been extended to hold more than a monolayer of sample and led to the development of the finite length cell (FLC); experiments conducted using the FLC have been since been published (Levy et al., 2015; please see the ‘Publications’ section). The thesis also describes Monte-Carlo simulations and a mathematical model designed to calculate the number of pairs of FCC particles touching one another in a packed bed of these particles diluted with non-porous particles. Experiments conducted in this way can allow the extrapolation of the diffusion coefficient to the equivalent amount of FCC that would form a monolayer.
In the future, the solvent used may progress to saline, and then synthesised stomach and/or oesophagus fluids and saliva in order to test the systems’ ability to withstand the human body's digestive fluids.
Throughout the project, various trips to Switzerland were undertaken for meetings and collaborations, including 3 weeks spent working at Omya’s laboratories in Oftringen, and meetings with the Department of Pharmaceutical Sciences at the University of Basel.
An overview of my research work in Nov. 2012: : at the time, the pink squares represent work that is not mine, the purple squares represent my current work and stubs into potential fruitful lines of investigation, and the blue boxes represent future work that I hoped to complete.
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(submitted as partial fulfilment for the degree of B. Sc. (Hons) Applied Chemistry)
Investigation of Modified Calcium Carbonates as slow-release agents for bioactive materials (September 2010 - March 2011)
This work was undertaken at the University of Plymouth under Professor G.P. Matthews, and was the foundation for my doctoral work. Below is the abstract of my completed and submitted dissertation, for which I obtained a score of 85%. If you would like a copy of my dissertation, please so not hesistate to contact me.
The desorption and diffusion characteristics of various grades of modified calcium carbonate (MCC) were investigated. A novel ‘zero-length’ (ZLC) designed for liquid systems was used, where an effective monolayer of sample was sandwiched between two fine stainless steel sinters. The ZLC was then connected to a high performance liquid chromatography (HPLC) system under high pressure to allow sufficient flow rate of the mobile phase (benzene in cyclohexane) through the sinter. The ZLC was then used to measure the diffusion from, and desorption within, the intra-particle structure of the benzene in cyclohexane system. The desorption and diffusion coefficient of a sample was calculated, and the sample with the slowest diffusion rate, and therefore the smallest coefficient, pertained to a more complex internal structure. When comparing the properties of the samples with their diffusion and desorption coefficients it is apparent that a combination of a high surface area and a smaller particle size makes for a slower diffusion rate.
The high surface area modified calcium carbonate (HSA MCC) was then analysed using mercury intrusion porosimetry (MIP), where the maximum pore size distribution of the sample was calculated from its unimodal distribution as 797.15nm. The unimodal distribution shows that the sample has distinct inter-particle and intra-particle pores.
The HSA MCC was subjected to nitrogen adsorption where its surface area was calculated using the Langmuir and BET equations as 145.42 and 93.50 m2 g-1, respectively. The BET isotherm gave a better fit, however both equations established that the HSA MCC had the largest surface area of all samples analysed during the investigation, which confirms its slow diffusion properties.
MIP data of the simply modified calcium carbonate (S MCC) and the averagely modified calcium carbonate (A MCC) were used to model the structures in Pore-Cor Research Suite after being intruded with mercury, and confirmed that the A MCC is more porous than the S MCC. The software generated a 3-dimensional void structure using an annealed simplex that fitted an Euler-Beta function. The software then modelled diffusion within the porous network, assuming Fickian diffusion, with diffusion coefficients based on Einstein-Stokes coefficients that were corrected for steric hindrance. These samples were chosen because they had significantly differing properties from one another. The diffusion simulation obtained the same results as the ZLC; that the A MCC diffuses much slower than the S MCC, therefore demonstrating that diffusion is certainly due to structural differences within the samples.
MCCs already have application in the paper, cosmetic and drug industry. The ZLC experiments and Pore-Cor diffusion simulation established that the diffusion characteristics are governed by the structure of the sample. Therefore, further research into characterising and investigating the structure that gives the slowest diffusion would be a promising investment into developing slow-release materials for various uses, as the MCCs could then be tailored to suit its use.
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The analysis of the waters of la Estación Hidrobiológica y la Laguna de Chascomús: effects on the Argentinean Silverside (July - September 2010)
During my undergraduate studies, I was lucky enough to obtain a 2 month analytical chemistry placement in Argentina via the International Association for the Exchange of Students for Technical Experience (IAESTE) run by the British Council. So, during the summer after my second year of study I flew to Buenos Aires to work in the Centro de Estudios Transdisciplinarios del Agua within the Veterinary Faculty at the University of Buenos Aires. I was overseen by doctoral students (at the time) Nahuel Schenone and Juan José Troncoso. For more information please see this external link.
When I returned from Buenos Aires, I entered an essay-based competition run by IAESTE, and was able to win the title of IAESTE Trainee of the Year 2010!
Below is an excerpt from the introduction of the report that I wrote, which includes all data collected. For a copy of the report, please so not hesistate to contact me.
The hydro-biological of Station Chascomús (la Estación Hidrobiológica de Chascomús) opened on November 7th 1943 and currently is the home to silverside from many different origins in order to help repopulate the area of pejerrey, as there are decreased numbers due to sport fishing and tourism. The hydro-biological station also carries out basic research.
The silverside (Odontesthes bonariensis), also known as the “pejerrey” in Spanish, is a highly valued food and sport fish both in Argentina and abroad, and has been introduced to Chile, Japan, and Italy.
Their typical habitats are ‘lagunas,’ the most common lenitic water bodies of the wet Pampa, an extensive loess plain under an East West climate gradient of decreasing rain. Lagunas range usually between 30 and 6,078 ha, with depths below 4 m and often rather less. Some of them maintain high-salinity levels because of marine origin or the increased EastWest aridity gradient. They lack thermal stratification and have a wide range of physical and chemical traits. Bottom sediment is mud like, with scarce clay, fine siliceous sand thicker than loess and abundant organic matter. Lower depths and the richness of loess in phosphorous usually result in a common eutrophic state.
This study was carried out in order to investigate the levels of trace metals and other analytes in order to determine the effects of these components on the Argentinean Silverside and the impact on the environment. The samples were taken from seven sites in “la Estación Hidrobiológica de Chascomús,” and a sample was also taken from “la Laguna de Chascomús.”
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