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Development of a lattice Boltzmann model to investigate the interaction mechanism of surface acoustic wave on a sessile droplet
Get PDFThis study focuses on the development of a three dimensional numerical model, based
on the lattice Boltzmann method (LBM), for two-phase fluid flow dynamics employing
a multiple-relaxation-time (MRT) pseudopotential scheme. The numerical model is
applied in the investigation of acoustic interactions with microscale sessile droplets (1-
10 µl), under surface acoustic wave (SAW) excitation, through the introduction of
additonal forcing terms in the LBM scheme. In the study, a range of resonant frequencies
(61.7 - 250.1 MHz) are studied and quantatively compared to existing studies and
experimental findings to verify the proposed model. The modelling predictions on the
roles of forces (SAW, interfacial tension, inertia and viscosity) on the dynamics of
mixing, pumping and jetting of a droplet are in good agreement with observations and
experimental data.
Further examination of the model, through parameter study, identified that the relaxation
parameters considered free to tune in the MRT, play an important role in model stability,
providing large reductions in spurious velocities, in both the liquid and gas phases, when
the values are specified correctly. It has also been discovered that employing a dynamic
contact angle hysteresis model increased the adhesion between the liquid droplet and the
substrate, improving the agreement with experimental findings by up to 20%. Lastly, an
investigation of various equation of state implementations revealed some fascinating
differences in droplet dynamics and behaviours, owing primarily to the physical
underpinning of which each is based upon.
The developed model is successfully applied in the examination of various scenarios
including SAW-droplet interactions on an inclined slope, droplet impact on flat
(horizontal) and inclined surfaces with and without SAW interactions, and dual SAW
interactions on a droplet at several configurations. The findings indicate the importance
of applied SAW power, especially in inclined slope scenarios, to overcome the inertia and
gravitational forces which act to counteract the droplet motion initiated by the acoustic
wave direction of travel.
Furthermore, a new multi-component multi-phase multi-pseudopotential (MCMP MPI)
LB model is proposed. The study details initial model development and verification for
classical benchmark cases, comparing to both the single-component (SCMP MPI) and
publicised data. Similar to its SCMP MPI counterpart, the model displays excellent
stability, even at high density ratios, and thermodynamic consistency. Comparison to the
SCMP MPI model reveals lower spurious velocities are generated in the proposed MCMP
model, approximately one order of magnitude lower. Close inspection of the interaction
force implementation shows they are analogous whilst similar surface tension values are
presented for both models. The proposed scheme signifies a new class of MPI model
capable of simulating realistic fluid compositions for use in applications of scientific and
engineering interest
Batch and continuous flow C-H functionalisation of azoles
Get PDFThis thesis describes the development of novel heterobenzylic, organometallic mediated C-H
functionalisation methodologies of alkylazoles under batch and continuous flow conditions.
Chapter 2 outlines the study of lithiation-substitution of unprotected alkyltetrazoles. Although
the double lithiation of unprotected alkyltetrazoles was found to be impractical for use in
synthesis, unprotected benzyltetrazoles underwent effective double lithiation to give
functionalised products in high yields after electrophilic trapping.
Chapter 3 details the development of lithiation-substitution protocols for N-cumyl protected
alkyltetrazoles. Two complementary sets of optimised conditions were identified in batch as
well as continuous flow conditions (identified through the use of thermal imaging), which can
be carried out at room temperature with high productivity. Enantioselective lithiationsubstitutions of N-cumyl protected alkyltetrazoles were also investigated.
Chapter 4 describes the development of metalation-substitution protocols for alkyl-1,3,4-
oxadiazoles. Optimal lithiation-substitution conditions were found to be at –30 °C in batch.
The unstable lithiated oxadiazole intermediate could also be trapped efficiently at room
temperature by adopting the flash chemistry approach under continuous flow conditions. The
structure of lithiated oxadiazoles in solution was also studied via VT in situ NMR to gain
insights into the reason behind the lack enantioselectivity when chiral lithium complexes were
employed for the lithiation-substitution
Investigations of digital interferometric microscopy techniques for industrial quality control applications
No full textAbstract currently unavailable. Please refer to PDF. Restricted access extended until 31.08.2025
Integrating genomic tools in strawberry breeding
Get PDFThe intense technological development in genotyping and phenotyping provided new
tools capable of clarifying the genetics of complex polyploids such as commercial
strawberries.
High-throughput genotyping was applied to the case study of a F1 population
representing the germplasm of Edward Vinson Ltd. breeding program. Thus, high density linkage maps were developed for the parental cultivars, Parental lines (PL) 1
and 2.
Secondarily, a high-throughput phenotyping protocol for strawberry fruit quality and
yield was developed and tested. Its output was integrated in a QTL study aiming to
understand the genomic regions underlying fruit phenotype. As a result, 54 stable loci
associated to fruit size, shape, and colour were mapped and analysed.
The results provide an insight to the structure of the strawberry genome and its regions
controlling critical fruit traits. The markers, maps, and methodology developed will
constitute a valuable resource in future genetic studies as well as commercial breeding
The strategic planning practices of small to medium enterprises in the food and beverages manufacturing sector in South Africa
Get PDFThis thesis examines the strategic planning practices of small to medium enterprises
(SMEs), to establish how SMEs can be better enabled to practice strategic planning. The
aim of this study is to use a qualitative approach to elaborate on the practice of strategic
planning by SMEs in South Africa.
Existing literature on the practices of strategic planning by SMEs in general and in the
food and beverages manufacturing sector in South Africa was reviewed and synthesised.
The synthesis informed the development of a theoretical strategic planning framework
to frame the empirical study.
The research followed the case study method and nine case studies were identified for
the main empirical study using theoretical sampling. There were at least three case
studies under each of the SME development stages on (i) very small, (ii) small and (iii)
medium enterprises. The use of case studies enabled the collection of data through in-depth interviews, observations and archival documents from the identified case studies.
A pilot study was conducted to test, refine and improve the data collection and
respective data analysis.
The research established that majority of the SMEs (i) lack an appreciation of the
benefits of practicing strategic planning and having a strategy, (ii) they also do not have
the strategic management knowledge and skills to facilitate the practice of strategic
planning on their own; The study further established (iii) why SMEs do not practice
strategic planning and instead focus more on operational planning to achieve their short-term goals and objectives, and (iv) highlighted challenges SMEs face in accessing
support available in South Africa.
The research contributes to knowledge on the practice of strategic planning by SMEs in
South Africa. This is achieved through (i) the provision of a proposed strategic planning
framework that SMEs can use to improve their practice of strategic planning (ii)
provision of an accompanying guideline that SMEs can use to better understand how to
use the proposed framework and (iii) a theoretical definition of strategy to standardise
the view of strategy by SMEs utilising the proposed strategic planning framework
What shapes cross-border merger and acquisition negotiations in the automotive industry?
Get PDFThe research evaluated the impact of contextual, structural, and behavioural factors in
shaping cross-border merger and acquisition (CBMA) negotiations between automobile
manufacturers. Recent years have seen an increase in CBMA activity in the automotive
industry, advanced by the necessity to share investments in alternative power sources for
engines and realise economies of scale and scope. The significance of the topic is reflected
by the essential role played by the automotive industry in the global economy. According
to Fortune (2020), the combined revenue of the top 10 automakers exceeded 1.70 trillion
in 2019. PricewaterhouseCoopers (2020) reported that Global Automotive M&A activity
accounted for 100 billion and approximately 800 deals in 2018, and over $77 billion and
around 850 deals in 2019. Despite the substantial deal value and volume, research has
repeatedly determined that over 70 per cent of CBMAs fail to deliver the promised results
due to the ineffective management of the negotiation process. Moreover, while the
different stages of the M&A process have been extensively investigated, research on the
M&A negotiation phase has been limited, and very few studies have attempted to
incorporate contextual, structural, and behavioural factors in analysing inherently
complex CBMA negotiations.
The study followed a pragmatist standpoint and adopted a sequential mixed-method
design integrating the macro-strategic and micro-behavioural levels of analysis. The first
phase based on a qualitative small-N focused comparative analysis case study on
identifying the type of precipitant originating turning points in CBMA negotiations
between automobile manufacturers. The second quantitative phase entailed a factorial
experimental design and questionnaires to evaluate motivational and relational factors'
role in shaping the negotiators' response to the previously identified precipitants. The
simulations extensively conformed to a real case, and the sample of experimental
participants consisted of executives with at least seven years of negotiation experience.
The findings indicate that negotiation outcomes are significantly influenced by elements
internal to the negotiation process, with contextual factors (including culture) exhibiting
only a marginal influence. The conclusions also highlight the critical role of coalition-building in shaping the negotiation process. The results supplement current literature and
provide a roadmap for managers to better prepare, identifying the three crucial
behavioural factors that shape negotiators' response to precipitants and significantly
influence the outcome of CBMA negotiations between automobile manufacturers: the
seller's motivation and power perception and the buyer's affective trust
Surface functionalized iron oxide nanoparticles for applications in biomedical sciences
Get PDFThis thesis focuses on the functionalization of iron oxide nanoparticles (Fe3O4) and their
applications in biomedical sciences. Each chapter represents an independent research project that
has been conducted within a different collaboration. For each project, magnetic Fe3O4 iron oxide
nanoparticles have been functionalized or modified to suit its requirements. This thesis aims to
show how versatile and most promising Fe3O4 iron oxide nanoparticles are, and how their unique
properties in size, shape, and magnetism can be utilized for a broad range of applications in
biomedicines.
Chapter 2 focuses on magnetic resonance (MR), computed tomography (CT), and intravascular
ultrasound (IVUS) as essential diagnostic imaging techniques and how iron oxide nanoparticles
can potentially be used as contrast agents across all three imaging modalities. Contrast agents are
commonly used to enhance the imaging quality and thus provide more detail for assessment.
However, previous studies using nanoparticles for MR and CT were prepared with surface coating
stabilizers, which in turn can compromise the use in clinical studies. In this chapter, gold-iron
oxide nanoparticles (Au*MNP) are presented as a multi-modal contrast agent. Using a chemically
grafting method without stabilizers, presenting nanoparticles with pristine surfaces that allow for
further functionalization in molecularly targeted theragnostic applications.
In Chapter 3, the response of HepaRG liver cells to nanoparticles is examined in two methods, 2D
and 3D cell culturing. By analyzing the cell response in 2D and 3D cultures an accurate estimation
of the toxicity of nanoparticles can be made. The toxicity of iron oxide was assessed using
commercially available cell assays (CellTiter-Glo and PrestoBlue), however, the experiments
suggested some restrictions that could alter the data and therefore resemble inaccurate results. For
this purpose, non-invasive imaging techniques based on impedance (xCELLigence system) and
Coherent Anti-Stokes Raman Scattering (CARS) were used to analyze the cell toxicity. The results
showed that those methods provided a much deeper insight into the cell viability and proliferation
of HepaRG cells. Furthermore, valuable data on the immediate effects in real-time and long-term
exposures can be captured of the same culture.
Chapter 4 presents the cell internalization process of iron oxide nanoparticles, captured using the
unique holographic cell imaging technique of a HoloMonitor M4 microscope. In most cases where
the cell internalization process is monitored, only one or two cells can be visualized and tracked at
the same time. This is not the case with this technique, where hundreds of cells can be
simultaneously visualized, analyzed, and monitored over time. Unlike single-cell observation, the
system takes pictures of the cell culture at a high capture rate, allowing to observe and interpret
the cell dynamics, cell morphologies, and cell reactions to nanoparticles (e.g., toxicity and
apoptosis). Measuring the kurtosis and skewness of MCF-7 cancer cells for 72 hours after
nanoparticle exposure, showed that cell splitting and proliferation took place, and no extraordinary damages or cell death was caused by the internalization of the particles. Furthermore, every step
of the internalization process was monitored and captured in visible data for the first time.
Chapter 5 demonstrates magnetic molecularly imprinted polymer networks and spheres (MMIPs)
for the selective binding of antibiotics. MIPs are polymers that can be synthesized with highly
selective and reusable binding sites. Their combination with magnetic iron oxide can be used as a
useful tool to monitor and remove antibiotic pollutants from freshwater sources and food products.
MMIPs are prepared using a microemulsion technique containing vinyl-functionalized iron oxide
to selectively bind the model antibiotics erythromycin (ERY) and ciprofloxacin (CPX). The results
show that MMIPs prepared using this technique are highly selective towards their respective
template molecule in methanol/water and milk matrix, are recyclable, and most importantly open
to modification.
In Chapter 6, zebrafish larvae are exposed to polyethylene glycol coated iron oxide supported gold
nanoparticles for further toxicity assessment. In general, toxicological data is gathered in vivo,
however, the translational values from in vitro to in vivo are sometimes questionable due to the
complexity of the organism. Zebrafish larvae are used as an intermediate method for in vivo
experiments, as they can be used 96 hours after hatching, unlike larger animals such as mice, rats,
or rabbits which take a much longer time to reach adulthood, sometimes up to 3 months. Also, a
single female zebrafish can spawn about 200-300 eggs per week, which can generate an extensive
data set from a small-scale experimental setup. The results presented in this chapter showed a
100% survival rate of all exposed zebrafish larvae between a range of concentrations from 0 - 2mM
(0 - 463.1 mg/L).
Chapter 7 summarizes the key findings and developments presented in this thesis, suggestions for
future work within each research project, and proposes future applications.
Chapter 8 includes a list of journal publications produced from this thesis.financial support provided from Heriot-Watt University (FOS
Design and implementation of machine learning algorithms for degradation estimation of Lithium-ion batteries and electrochemical capacitors
Get PDFLithium-ion (Li-ion) batteries and electrochemical capacitors (EC) are the preferred
energy storage technology in stationary storage systems as well as other critical applications to the decarbonisation of our infrastructure including electrical vehicles,
busses, trains and planes. The gradual degradation of energy storage devices, however, is a major concern for the adoption of storage technology across a wide range
of industries. Li-ion batteries and EC cells continuously degrade with time. Their
degradation rate is highly dependent on their construction and the wide variation
in operating conditions. Given that a cell’s degradation is an unavoidable effect, it
is critical to understand its degradation and predict its lifetime to ensure resilience
and reliability.
First, the research in this thesis concentrates on understanding which factors
affect the degradation of Lithium-ion batteries. Whilst the operating temperature
is regarded as one of the highest stress factors accelerating battery degradation, the
effect of other stress factors such as discharge and charge current, charge cut-off
current and depth of discharge, is an understudied topic. The research in this thesis
describes a half-factorial design of experiment (16 test cases) consisting of a total
of 96 batteries from two manufactures. Two machine learning algorithms, random
forest and lasso regression are trained on the generated data and subsequently ranked
all five operational factors and their two-way interaction. The results indicate that
the two-way interaction effects of charge current and depth of discharge are in the
top 3 significant stress factors for the capacity fade in Li-ion batteries, which was
previously not commonly accepted knowledge in the battery literature.
Secondly, in this thesis, EC degradation at extreme temperatures is investigated
due to a lack of studies addressing EC cell operation outside manufacturer specified
temperature operating envelope. This is critical for EC operation in extreme environments such as drilling where temperatures can reach up to 200 °C. The research
first develops a design of experiment approach to generate data for EC degradation
under high-temperature conditions ranging from 80°C to 200 °C. The obtained data
is then used as input to a Gaussian process algorithm that estimates cell degradation in pre-specified temperature conditions with a mean absolute per cent error of
1.47%.
Finally, the thesis addresses the problem of state of health estimation of Li-ion
battery cells. State of health is a variable that characterises the condition of an
energy storage device throughout its lifetime and is typically measured as capacity fade or resistance increases. SOH estimation is critical to recognise a sudden degradation of a battery cell and greatly affects battery state of charge (SOC) calculation. Therefore, the research proposes a battery chemistry and design agnostic
machine learning pipeline. The method uses Li-ion battery charge curves as input and estimates degradation measured as capacity. This eliminates the need for
time-consuming and computationally expensive physics of failure and electrochemical models traditionally used for SOH estimation purposes. The pipeline operates
by passing incoming data streams through a hierarchical sequence of processing
steps to fuse them into a model. Each step of the pipeline has the goal of eliminating or minimising the typical disadvantages plaguing machine learning-based
algorithms to date. Namely, the pipeline engineers feature by summarising each
incoming charge curve data stream to one single value, thus becoming robust to
different data captures. In the case of limited training data, the pipeline introduces
adversarial examples, minimising overfitting. Additionally, the pipeline also associates a confidence interval with each SOH estimation and re-calibrates the models.
Results indicated that when deployed on Li-ion batteries subjected to a fast-charge
protocol, the pipeline achieved a mean absolute percent error of 0.45%.
Overall, the research in this thesis highlights the promise of combining machine
learning models with a design of experiment-based data generation phase for a better understating of degradation of complex dynamic electrochemical systems such
as lithium-ion battery and electrochemical capacitors. Furthermore, the proposed
methodology accurately estimates state of health of complex non-linear systems and
has the capability to scale to other energy storage devices in the future
The development of neutral Ni and Pd complexes with [N,O] ligands for ethene polymerisation and cross-coupling catalysis
Get PDFA series of 2-(arylamino)-5-methylcyclopent-2-en-1-one proligands, derived from the
condensation of maple lactone with aryl amines, were developed. Using these [N,O]
proligands, complexation experiments were carried out by deprotonation with NaH and
reaction with Ni and Pd precursors to yield square planar complexes containing
5-membered [N,O] chelates. The Ni complexes featuring PPh3 and aryl (phenyl and
ortho-tolyl) coligands were trialled for the polymerisation of ethene. Precatalysts with
N-Dipp (Dipp = 2,6-diisopropylphenyl) substituents were found to exhibit moderate
activity when activated with Ni(cod)2 or B(C6F5)3. The catalytic activity was highly
dependent on temperature, with the catalysts most active at 80 °C. Significant differences
in the nature of the polymer were also found when changing the activator, with polymers
using Ni(cod)2 as the activator producing a highly branched viscous polymer, compared
to colourless, solid polyethene with a lower number of branches produced with B(C6F5)3.
The most active nickel precatalyst, featuring the N-Dipp substituent, was trialled for the
copolymerisation of ethene and CO, the polymerisation of 1-hexene, and the
polymerisation of methyl acrylate; no copolymerisation or polymerisation was observed.
A palladium complex bearing the Dipp-substituted [N,O] ligand with PPh3 and Cl
coligands was tested as a catalyst for the Suzuki-Miyaura cross-coupling. The complex
was found to be highly active under mild conditions and under air. The scope and
tolerance of this reaction was then investigated which showed good conversion for all
aryl bromides tested that featured electron-withdrawing groups. More electron-rich
substituents could be reacted successfully by increasing the temperature of the reaction
and increasing the reaction time. Only boronic acids featuring strongly
electron-withdrawing groups showed limited activity. Pinacol esters also showed good
activity towards the Suzuki-Miyaura cross-coupling. The cross-coupling reaction of aryl
chlorides with phenyl boronic acid was also achieved in mild conditions but required an
elevated temperature of 40 °C for 24 hours
An assessment of the Natural Hydraulic Lime binder-aggregate interface : utilising indigenous Scottish aggregate materials
Get PDFNaturally Hydraullic Lime (NHL) binder is commonly specified for use in Scotland
where it is regarded as a suitable replacement material in the conservation of historic
buildings. Compared to calcium limes (CL), NHL mortars are considered to possess
favourable characteristics; such as greater resistance to wind, rain and damage by frost,
leading to their prevalence in the harsh Scottish climate. Lime mortars are perceived as
playing a leading role in reducing carbon footprints in the construction and conservation
sectors as a whole, whilst an increased awareness of local raw, region specific aggregate
materials could further assist in this reduction. This research has investigated the
performance of NHL 5 mortars, including Scottish aggregate materials, on account of
several criteria which are indicative of overall performance and durability. An emphasis
has been placed on trying to isolate the effects of the Interfacial Transition Zone (ITZ),
considered detrimental in cements, this was achieved by producing mortars which
contained variable quantalities of aggregate and binder. Mortar specimens have been
assessed on account of their strength, sorptivity, carbonation depth, porosity and electrical
impedance as a means to attempt to isolate the effects of the ITZ; while a second series
of testing has attempted to examine the strength and failure patterns of a scaled up
interface between NHL 5 binder and natural stone. The research has highlighted that
grading and textural features such as intra-clastic porosity can have more of a profound
effect on the interface and overall strength achievable in lime mortars. Furthermore, the
research suggests that a greater uptake of local, mineralogically varied aggregates could
be used as part of a low carbon strategy
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