PhD, EngD, MPhil and MSc by research theses (CDS)

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Open Access
Breaking the Mould of the Orthodox Approach to Security Sector Reform: A Case Study of Israel’s Civil-Military Relationship
(2021-06) Westerman, I; Watters, B
Post-conflict Security Sector Reform (SSR) is a complex and difficult task which offers few historical examples of success. The challenges that SSR encounters are compounded by the western liberal democratic origins of the majority of the civil-military relations (CMR) theory from which it draws. By their nature, these theories are ill-suited to most post-conflict scenarios. This thesis offers a new perspective on the problem by suggesting that the use of elements of other less orthodox, but nonetheless still democratic, models of CMR would help SSR programmers to develop more appropriate objectives. It further argues that the Israeli system of CMR is an example of one such model. Using a critical realist approach, the thesis presents a single case study to investigate the research question: How has Israel’s CMR evolved since the state was founded in 1948? It employs thematic analysis to evaluate data obtained from a series of semi-structured interviews conducted with influential Israeli elites. From this, three ‘Big Ideas’ are identified. If adopted, these could help to break the mould of the previously unfruitful, orthodox approaches to post-conflict SSR. They are: first, that culture and history must impact the design of all SSR programmes from the very start; second, that more flexibility must be shown regarding military involvement in defence policy-making; third, that if the benefits of more unorthodox approaches to SSR are to be realised, clear provision must also be made for the system to adapt over time. The lens of critical realism brings a fresh perspective to the hitherto well documented subject of Israel's civil-military relationship, and the development of a novel analytical framework (CIPMIS) contributes to the wider body of knowledge in this field. Most significantly, analysis of this unique interview dataset enables the Israeli experience, for the first time, to directly inform understanding of post-conflict SSR.
Open Access
Crowdsourcing with Serious Games for Defence Procurement
(2020-11) Oates, E P; Ringrose, T P
Human Factors Engineering within UK defence procurement relies on small numbers of users picked from small user populations to help develop and test human-computer interfaces for new defence equipment. The delivered equipment is only exposed to a full assessment through mass user involvement when in service, which is the most costly point of the procurement process at which to identify any shortcomings. A prototype Electronic Warfare system interface was used to illustrate proposed new procurement processes. A ‘Serious Game’ is defined as a computer-based game used for a business purpose, and the research began by building such a game to simulate the prototype interface, which was made available through a web browser to all defence personnel. The Serious Game was developed using Open Source coding techniques and internally Crowdsourced allowing the design of this defence equipment human-computer interface to be developed and tested through a wider than usual range of user perspectives. The aim was to show how end-user experience might be enhanced and procurement costs reduced by exposing defence equipment to a wide range of users ahead of the In-Service procurement phase. This project reports on technical aspects of web-based game design and implementation, the cultural and organisational structures that affect the Crowdsourcing, and the quantitative results from controlled experiments using the Serious Game. The results show that while Open Source coding engaged with the audience at a minimal level, Crowdsourcing a Serious Game has the potential to be effective in providing a measurable benefit to defence procurement.
Open Access
Cuticular hydrocarbon analysis for the identification, ageing and geographical variations of forensically important blowflies
(2022-02) Kula, Canan; Moore, H E; Drijfhout, F P; Shortland, A.
Calliphoridae (blowflies) are important for forensic entomology as they are often the first group of insects to inhabit decomposing remains. To estimate the minimum post-mortem interval (PMImin), blowfly samples are collected from the crime scene and identified, and then the age needs to be determined for each species. Accurate species identification is crucial, as varied species have different life-stage timings. Previous studies on Diptera have shown the possibility of using cuticular hydrocarbon (CHC) analysis to aid species identification, ageing and ultimately calculating PMImin. However, since prior research was conducted at constant temperatures, the effect of fluctuating temperature on chemical profiles and the stability of CHCs in the field remains unclear. This thesis aims to examine the CHC profiles of Lucilia sericata and Calliphora vicina reared outdoors in the United Kingdom, Germany and Turkey in terms of species, age and inter-population differences. The first study investigates whether the stability of the CHC profiles of two colonies reared outdoors can be used to identify species-specific characteristics. The second examines the effects of fluctuating and constant temperatures on the CHC profiles of the life cycle stages and the use of their chemical profiles for age estimations. The final study aims to determine the differences in CHC profiles of the same species living in different habitats and whether they can be used to distinguish populations. The CHC profiles of the samples were extracted and analysed using Gas Chromatography-Mass Spectrometry (GC-MS). The statistical interpretation was carried out using Principal Component Analysis (PCA). The results showed that CHC profiles differed significantly between developmental stages by species, age, rearing temperature and geographical location. This study highlights that despite environmental factors affecting the stability of CHC compositions, the CHC analysis can be used as a complementary tool for identifying and ageing the species. Furthermore, the effects of ambient temperature and geographical variation on CHC profiles may be useful for determining inter-population variations.
Open Access
Cutting a Gordian knot? Understanding the relationship between culture and process, environment, and people in military planning.
(2021-07) English, N G; Dodd, Lorraine
Military planning is designed to make sense of rapidly changing, dangerous and stressful environments and generate activity that influences an adversary’s behaviour against their will. This thesis explores the experience of military planning and why some practitioners appear to find structured planning processes difficult to use in practice. A review of military specific literature revealed that the human experience of military planning is relatively underdeveloped in comparison to other more technically focussed areas. This thesis addresses that gap through a comprehensive analysis of planning and decision-making research. Using a critical realist research design, it exposes a rich, multi-disciplinary body of knowledge to develop a transferable theoretical framework. A thematic analysis of culture and process, environment, and people then forms the foundation for a revelatory case study of real-world planning conducted in Afghanistan in 2014. This thesis argues that practitioners find structured planning difficult because, under certain conditions, their expectations and contextual understanding become dislocated from their environment. It proposes that this sense of dissonance is grounded in the inter-relationship between socio-cultural norms and expectations, naturalistic behaviour, and perception of the environment. Rather than an isolated phenomenon, it suggests that dissonance acts as the trigger for adaptation and as an indicator of impending instability and fragility particularly when relative complexity is high. In many ways, planning practice resembles a complex adaptive reflexive system; it adapts not only in response to the environment and the problem faced but also to the emotional experience of the practitioners within it. Finally, it recommends a number of potential strategies to increase the stability and robustness in military planning under a wider range of environmental conditions than is currently possible.
Open Access
Development of a K-band FMCW flexible radar prototype for detection and classification of nano-drones
(2020-12) Zulkifli, Safiah Binti; Balleri, Alessio
Nano-drones of the size of an insect can be used to perform stealthy surveillance or to gather intelligence crucial to attack roles at a relatively short range and within enclosed spaces and buildings. Conventional radar systems have been optimised to detect and classify bigger targets and are not specifically designed to detect nano-targets of less than 5 cm in size. Hence, this project aims to develop a radar system to detect and classify an insect-like size drone that corresponds to a low RCS. This will exhibit challenges due to the nature of the weak echoed signal that will be masked by an uninterested target with a stronger echoed signal. To tackle this sort of problem, micro Doppler extraction is applied for better target detection. This type of target that consists of a bladed propeller will give rise to a significant micro-Doppler signature that will contribute to the discernment of the interested target. An ad-hoc S-band FMCW radar prototype using off-the-shelf components An ad-hoc S-band FMCW radar prototype using off-the-shelf components has been successfully delivered. This prototype act as a groundwork for the next research phase of design and development for a higher frequency. Then, with the strong foundation of the S-band demonstrator, a flexible K-band FMCW radar prototype has successfully delivered aiming to meet the research purpose. The radar prototype offers a wide range of flexibility for the user to select the radar parameters (like operating frequency, ramp duration, bandwidth and integration time) and configure its performance. It will collect the signatures of real targets (nano-drone model) so that their performance can be assessed on experimental data. The results demonstrated that a nano-drone, a small size of less than 5 cm can be detected with the radar prototype developed.
Open Access
Development of an analytical framework to assess the risks posed to soil by emerging contaminants and chemicals of military concern.
(Cranfield University, 2022-11) Persico, Federica; Temple, Tracey J.; Coulon, Frederic
Soil provides multiple essential functions, such as provision of food and raw materials, a platform for urban development and human wellbeing and as a filtering and transforming medium. Many unregulated contaminants, often termed emerging contaminants, are globally released on soil creating potential risks, especially when undetected leading to significant impact on environmental receptors. The UK ministry of Defence plays an important role in soil protection as the biggest holder of Sites of Special Scientific Interest (SSSI) in the UK as well as being an active polluter in these protected areas through essential training activities. Therefore, there is a need to improve methods for early identification of emerging contamination to avoid long term environmental impacts and costly remediation. The research undertaken for this thesis has contributed to the development of a soil analytical framework to facilitate early identification of the deleterious effects of emerging contaminants and chemicals of military concern on soil. During this research two different scenarios were considered, firstly, when there is a significant body of ecotoxicological data available for a specific contaminant in the literature and secondly, when ecotoxicological data is not available. A scale based on potential hazards was created for the first scenario, which aims to classify chemicals into three categories - low, medium, and high environmental hazards. This scale serves as an inexpensive method to identify the risk of soil degradation. Results from this research showed that for the contaminants of interest (e.g. 1,3,5-trinitro-1,3,5-triazine - RDX, 2,4,6-Trinitrotoluene - TNT, Perfluorooctanoic Acid - PFOA, Perfluorooctane Sulfonate - PFOS and Cypermethrin) the low-level hazard values were lower than expected. These values were expected to correspond to existing Soil Screening Values (SSVs) and Ecological Soil Screening Levels (Eco-SSL), meaning that the contaminants are likely to have a negative impact on the soil at lower concentrations. For the second case, when data is not available experiments need to be undertaken to generate primary data. Insensitive High Explosives (IHE) compositions were identified as lacking data and explosive residues were collected and soil mesocosms were carried out to define the long-term consequences on soil. Field experiments were used to quantify IHE residue deposition concentrations from a standard 155 mm artillery shell, which was then used to estimate potential contamination after 100 detonations. These values were used to estimate low, medium and high contaminant concentration for soil mesocosm studies to quantify the impact on soil using indicators identified through literature review. A standardised procedure was developed based on this, which quantifies the consequences of explosives on soil. This procedure revealed that soils that are already degraded are more susceptible to the impact of explosives, which primarily affects the chemical and biological properties of the soil. . Specifically, this work has shown that the frequent use of IHE filled munitions on training ranges will have an effect on the quality of the soil even when low quantities of energetic residue are deposited. Results for this thesis represent a first step towards a more comprehensive soil analytical framework development providing early identification tools for soil protection.
Open Access
Effects of Particulate Contamination and Jet Fuel Chemistry on the Nucleation of Water and Ice in Aircraft Fuel Systems
(Cranfield University, 2022-04) Ugbeh-Johnson, Judith; Carpenter, Mark; Mai, Nathalie; Williams, Mike
The aviation industry is currently facing increasing environmental and energy challenges regarding its fuel use. Research is therefore currently under way to develop new sustainable aviation fuels. Understanding the properties of these fuels (along with the changing properties of existing fuel types) is required to understand their impact on aircraft fuel systems. Water solubility, water settling and ice formation in fuel are such properties of interest. The presence of water in jet fuel/fuel systems has been a long-standing issue in the aviation industry. Therefore, it is important to precisely identify the conditions and features that may exacerbate this phenomenon, understanding how fuel composition, temperature, water droplet sizes, flowrate and pipe surface affect ice formation and water solubility. Currently, there is relatively limited data regarding water solubility/settling rate and ice formation in sustainable fuels, specifically those specified in ASTM D7566. This work gives a comprehensive account of the recent advances and technologies in the literature indicating conditions that might lead to the nucleation of water and ice in aircraft fuel systems. These conditions have then been applied to characterizing dispersed water droplets in alternative fuels and conventional Jet A-1. Subsequently, the requirements have been applied to the design, set up, and effectiveness of an ice test rig to understand the types and amounts of ice that can be produced from different sustainable aviation fuel blends. In doing so, this work has helped shed light on the role of fuel composition in ice accretion and whether ice accumulation on a pump inlet strainer may impact pump performance. Furthermore, the results from this work will serve as a basis for design guidelines to minimise ice formation within an aircraft fuel system and help identify some potential/sustainable jet fuel candidates for ASTM D7566 certified jet fuels.
Open Access
Enhanced Microwave Imaging of the Subsurface for Humanitarian Demining Applications
(2020-07) Wirth, Sebastian G.; Morrow, Ivor L.
This thesis presents a theoretical analysis and applied evaluation deploying ground penetrat ing radar (GPR) for landmine detection. An original contribution has been made in designing and manufacturing a light-weight, low-cost, fully polarimetric antenna system for GPR, enabling easy transportation and as sembly. This facilitates extensive use by various smaller communities in remote areas. By achieving the goal of supplying various smaller communities with advanced ground pene trating radar technology the technological standard of landmine detection can be improved beyond existing solutions such as metal detection or manual probing. The novel radar system itself allows detection of various subsurface targets of different shapes and sizes, metallic and non-metallic, in a number of different soils, such as sand, loam or gravel and therefore can be used in versatile environments. The GPR system has been realised by designing novel light-weight, 3D printed X-band horn antennas, manufactured from single piece plastic then copper electroplated. These an tennas are 50% lighter than their commercial equivalents. They are incorporated in an an tenna array as a group of four to allow full-polarimetric imaging of the subsurface. High resolution images of landmines and calibration targets were performed in the subsurface over an experimental sand test bed. For performing subsurface measurements in the near-field, four novel gradient-index (GRIN) lenses were designed and 3D printed to be incorporated in the apertures of the X band antennas. The improved target detection from these lenses was proven by scanning the test bed and comparing the imaging data of the antenna array with and without lenses attached. A rigorous theoretical study of different decomposition techniques and their effect on the imaging and detection accuracy for polarimetric surface penetrating data was performed and applied to the gathered imaging data to reliably isolate and detect subsurface targets. Studied decomposition techniques were Pauli decomposition parameters and Yamaguchi polarime try decomposition. It was found that it is paramount to use both algorithms on one set of subsurface data to detect all features of a buried target. A novel temporal imaging technique was developed for exploiting natural occurring changes in soil moisture level, and hence its dielectric properties. Contrary to the previously intro duced imaging techniques this moisture change detection (MCD) mechanism does not rely on knowledge of the used measurement setup or deploying clutter suppression techniques. This time averaged technique uses several images of a moist subsurface taken over a period while the moisture evaporates from the soil. Each image pixel is weighted by the phase change occurring over the evaporation period and a resulting B-scan image reveals the subsurface targets without surrounding clutter. Finally, a multi-static antenna set-up is examined on its capability for suppressing sur face clutter and its limitations are verified by introducing artificial surface clutter in form of pebbles to the scene. The resulting technique was found to suppress up to 30 The GPR antenna system developed in this thesis and the corresponding imaging tech niques have contributed to a significant improvement in subsurface radar imaging perfor mance and target discrimination capabilities. This work will contribute to more efficient landmine clearance in some of the most challenged parts of the world.
Open Access
Female police body armour : improving comfort, protection, and testing.
(2021) Malbon, Christopher; Carr, Debra J.; Knock, Clare; Critchley, Richard
There is a paucity of published research into female body armour resulting in a lack of evolution in design and testing solutions. A series of surveys and experiments were designed to extend the knowledge relating to female body armour, focusing on comfort, protection, and testing. Comfort was shown to be improved through professional fitting and sizing of new bras, with a sports bra being reported as most comfortable after refitting by 77% of participants. Statistically significant differences in key anthropometric measurements around the breast area were identified between bra types, including bust to bust length, bust circumference, and bust prominence. Exposure of the anterior lateral region of the body was greater compared to the posterior lateral region for female police officers, particularly around the breast area, (exposed anterior lateral breast area – underwired bra: mean 55%, max 72%; sports bra: mean 57%, max 75%). A comparison of three backing materials used for the assessment of back face signature (BFS): Roma Plastilina No1 (RP1); 10% ballistic gelatine; SEBS gel; showed that there were statistically significant differences between the three materials. 10% ballistic gelatine had the greatest variation in measured BFS with both projectiles (9mm; BFS 21.5 – 42.3mm: 0.357”; BFS 31.5 – 67.3mm). RP1 had the smallest variance in measured BFS with both projectiles (9mm; BFS 17.6 – 30.9 mm: 0.357”; BFS 18.9 – 32.5 mm), however, there were statistically significant differences in the spread of results for RP1. The knowledge gained is enabling the development of new guidance for female police officers on improvement in comfort when wearing body armour by the Police Federation. Designers of body armour have information on the effects of bra type on breast shape enabling future designs of body armour to be more tailored to shape, enable a better fit, and reduce the risk of air gaps under the armour. Understanding of the differences in three backing materials will enhance the development of future testing methods for female body armour, which will deliver improvements in the safety of body armour.
Open Access
First World War Grave Concentration on the Western Front: Hooge Crater Cemetery, Belgium
(2021-04) Martin, Victoria; Shortland, A.; Harrison, K; Braekmans, D
The First World War took place between 1914 and 1918, with conflict occurring in Europe and across the globe. By the end of the War, the bodies of the British and Commonwealth dead were scattered across France and Belgium. It was decided to move single graves or small cemeteries into bigger cemeteries that were being built by the Imperial War Graves Commission. This process was called “concentration”, and involved searching the battlefields for graves, then excavating and attempting to identify the bodies present, prior to their reburial in a concentration cemetery. This thesis focuses on the concentration process and specifically examines a sample of graves from Hooge Crater Cemetery, Belgium. The main research aim is to understand the range of errors that occurred during concentration and identification, and how prolific they were. A historical and literature review was completed, followed by the analysis of data from 109 graves from Hooge Crater Cemetery that were re-exhumed in 1920. This proved that within the sample, a high number of errors occurred in the original concentration work. Following this, 163 burial returns containing the details of 1013 graves from Hooge Crater Cemetery were selected for detailed analysis. The information from these burial returns was gathered and reviewed, and where possible was plotted onto First World War trench maps. This data provides new insights into where and when bodies were concentrated, the type of methods used for identification and how these methods changed over time. The research presented here demonstrates that identification rates varied, and were influenced by several factors including burial location, quantity of body present, time of concentration and primary identification method used. Overall, this thesis expands our knowledge of First World War grave concentration, including how the battlefields were searched and how bodes were identified.
Open Access
Forensic Toxicology in Embalmed Human Remains
(2021-04) Lloyd, Richard G C; Harrison, K; Moore, H; Mai, N
Within the human body, vitreous humour, cerebrospinal fluid and synovial fluid are all contained within anatomical compartments that, by virtue of their relative avascularity, provide considerable protection from contamination during the embalming process. Analysing samples taken from embalmed medical school cadavers, and using an entirely novel headspace GC/MS method, the concentration of formaldehyde in all three fluids is shown to be significantly less than has previously been assumed in the literature. Using a newly-developed LC/Q-ToF method, the stability of fifteen drugs of forensic interest in representative concentrations of formaldehyde is then reported. The study is prompted by the fact that United Kingdom nationals are dying abroad with increasing frequency. Following repatriation of their bodies, an autopsy may be undertaken before permission for a funeral is granted. Although toxicological screening may form an important part of the investigative processes, there exists a large degree of uncertainty surrounding the reactive nature of formaldehyde, the main constituent of embalming fluids, with substances commonly implicated in drug-related deaths. It is the case, therefore, that in repatriated bodies, all of which are routinely embalmed before leaving the country in which death occurred, the presence of formaldehyde can cause significant problems for the forensic toxicologist. Although a number of papers in the past twenty years have investigated the challenges of drug detection in embalmed tissues, they have largely examined the problem from the perspective of histological samples preserved in formalin. While some of this work has, by implication, considered the analysis of samples taken from embalmed bodies, no studies have addressed directly the specific problems arising in the toxicological analysis of embalmed and repatriated bodies. The studies reported within the thesis demonstrate that there is considerable merit in undertaking further work on the usefulness of these fluids in the toxicological analysis of embalmed and repatriated nationals
Open Access
The Gordian knot of interdependence. A study of interpersonal team dynamics among RAF ground crew during the Western Desert campaign, June 1940 – February 1943.
(2021-08) Cooper, Michael J; Zaidi, I; Collantes Celador, G
This thesis is a study of the previously neglected area of organisational development dealing with interpersonal team dynamics amongst Royal Air Force (RAF) ground crew during the Western Desert campaign June 1940-February1943.In addressing this lacuna, particular emphasis is placed on the pilot-fitter-rigger team, an integral part of the Desert Air Force and its constituent squadrons. Although the pilot was designated air crew and not ground crew, to disregard his presence and influence on the team dynamic would not represent the team as it functioned. Their combined skills set enabled the Desert Air Force to adapt to the demands of what was then a modern war, waged in the challenging environmental, logistical, and operational conditions of the Western Desert. Via qualitative research this thesis examines the primary question, ‘How did the pilot-fitter-rigger team in the Desert Air Force during the Second World War form a small, resilient, and effective team? ’The thesis also tests the hypothesis ‘Whether or not the team of the pilot-fitter-rigger team in the Desert Air Force during the Second World War constituted a small, resilient, effective team. ’The null hypothesis being, ‘Neither Britishness nor the peculiar and particular desert environment played a significant role in creating the pilot- fitter- rigger small team into a resilient and effective entity.’ This thesis is based primarily on qualitative research, both in terms of organisational development theory and military history contained in both primary and secondary sources relating to human endeavour. The research involves a critical literature review, and where practicable, field visits along with interviews with established historians, technical experts, serving RAF personnel, and Second World War veterans. An element of quantitative data is also employed and considered where logistics, combat strength, and size of air fleets are concerned. The quantitative component is small and synthetic in nature, and therefore does not influence the qualitative data component beyond providing data. This application of new knowledge relating to ground crew in a desert combat situation makes a novel contribution to academic knowledge by building on previously established peace time organisational development theories and conducting new empirical work in the examination of the organisational development of RAF ground crew. This new and novel contribution will be of use to the academic community and researchers at large and organisational development practitioners, when developing an understanding of small team dynamics; as well as military historians and the wider public domain for both educational and leisure research. From the research findings and discussion this thesis concludes that both the research question and hypothesis have been tested and found that the pilot-fitter-rigger team in the Desert Air Force during the Second World War did form a small resilient and effective team. The thesis also found that peacetime organisational development theories also applied in a wartime combat situation, making them, at least in these two contexts, transferable proposition. The thesis tested the null hypothesis and concluded that both Britishness and the peculiar and particular desert environment did play a significant role in creating the pilot- fitter rigger team into a resilient and effective entity.
Open Access
High frequency AC power and data distribution system
(2011-11) Lourdes, Steve; Luk, Patrick Chi-Kwong
At present, power delivery issues are becoming a concern with modern state of the art electrical and electronic systems. The existing power networks, namely the centralized power architecture and the DC distributed power systems are struggling to cope with rigorous demands in some application areas. While active research to improve the current system is being relentlessly pursued, a more radical approach proposing a new power distribution system is increasingly drawing attention. High frequency AC (HFAC) power distribution architecture has been identified as a viable alternative to existing and future systems. The HFAC distributed power system (DPS) was initially proposed in the early 80s for space application and since then it has been considered for many modern ground based applications. This dissertation presents a fresh perspective to the problem by challenging the current notion of viewing the HFAC DPS merely as a passive power distribution system. The possibility of converting the existing system to a more intelligent architecture is investigated. Two fundamental features identified to be crucial for this implementation is the ability to communicate and to control power flow between the various power processing structures in the system. Developing the ♯enabling technologiesα is the primary focus of this research. A data modem designed to enable bidirectional multi node communication over the HFAC bus satisfies part of this requirement. The ability to control power flow is achieved by introducing digital control in the front end HFAC inverter. It is shown that intelligent management of the HFAC DPS offer potential efficiency benefits previously not possible in the traditional implementation. At the subsystem level, the front end inverter, the point of load (POL) converter and the communication module are investigated in depth. Extensive mathematical modelling is undertaken to develop optimal design guides to improve performance of the subsystems. Prototypes are constructed and the models are experimentally validated. In the case of the front end inverter, a multi stage inverter with parallel operation capability incorporating digital control is presented. An integral cycle converter is investigated as part of the POL subsystem and optimal synthesis pattern that improves power factor is identified. The communication subsystem constitutes the HFAC data modem described above. The modem emulates Ethernet style communication and interfaces to a host system via a simple serial communication link. All communication over the HFAC bus is performed transparently to the host. This dissertation contributes to the improvements of HFAC DPS at both the system and subsystem levels. At the system level, implementation of intelligent management of the HFAC DPS is shown to be viable and offers opportunities for improved performance and flexibility not previously possible. At the subsystem level, performance improvement to the individual power processing structures in the system is presented.
Open Access
The Ignition Behaviour of Energetic Materials Under Confined Cookoff
(2018-09) Stennett, Christopher; Akhavan, Jacqueline
In a series of experiments and theoretical work, the process of ignition in confined energetic materials has been explored and understanding gained. Early work focused on the direct observation of the cook-off process but was hampered by the available technology. In more recent work, dynamic measurements of the deformation of the confinement have been explored, and refinements to the direct observation method have been made that make use of recent advances in camera technology. We have observed, for the first time, complex melting and development of gas spaces within which the early stages of ignition take place, and propose a new mechanism by which violent cook-off responses might develop in certain explosives
Open Access
Internally bevelled conoidal entry wounds in sandwich bones; their genesis, impact dynamics and macroscopic and microscopic morpholog
(Cranfield University, 2021-01) Rickman, John; Painter, Jonathan; Hazael, Rachael
Projectile trauma to the sandwich bones of the neurocranium is of considerable forensic anthropological importance due to the high lethality associated with gunshot wounds to this anatomical region. The internally bevelled conoidal wound that typically results from perpendicular projectile impact has long been considered diagnostic of bullet involvement and is utilised in both differential diagnosis of gunshot trauma and in making trajectory determinations using the direction of bevel asymmetry as an indicator. However, despite the importance of these activities in forensic anthropological casework the fracture mechanisms underlying bevel formation have remained elusive, with multiple hypotheses presented but few empirical investigations carried out to test them. Further diagnostic complexity has been introduced by the recognition that bevelling also results from low-velocity impacts and that taphonomic agencies can both modify and create internally bevelled fractures. Despite the fact that bone is a complex hierarchical material the majority of analyses of projectile entry wounds in sandwich bones have been conducted at the macroscopic scale, leaving important questions as to whether lower scales of organisation may yield signatures of diagnostic importance. This thesis presents the findings of an experimental investigation into the fracture mechanisms that underlie internal bevelling and presents an analysis of the relationships between the dynamics of impact and quantitative wound morphology. A refined nomenclature for the components of internally bevelled fractures is presented and the layers composing the bevel formally defined. This thesis also presents a Scanning Electron Microscope (SEM) analysis of the effects of projectile impact on compact bone at lower hierarchical scales of bone organisation. Examination of fracture morphology with micro-computerised tomography (µ-CT) coupled with high-speed videography of the impact events revealed a novel cone cracking mechanism that fundamentally changes our understanding of bevel morphology. This mechanism explains how internal bevelling results from both low- and high-velocity impact events and suggests caution should be applied to trajectory determinations made using bevel asymmetry alone. Quantitative analysis of the perforation event revealed, for the first time in sandwich bones, a power relationship between incident velocity and absorbed kinetic energy. SEM analysis of cortical bone around the entry captured the early genesis of conoidal wounds through ring crack formation. Analysis of the periphery of the entry revealed two types of plastic deformation that are suggestive of changes to hydroxyapatite (HA) crystal structure that may be of diagnostic utility. Collectively, the findings presented in this thesis will enhance the diagnosis and interpretation of conoidal wounds in both forensic and archaeological contexts.
Open Access
Investigation into the fate and transport of Insensitive High Explosives in sandy soils to inform the development of a computational simulation
(Cranfield University, 2022-08) Gutierrez-Carazo, Encina; Ladyman, Melissa; Coulon, Frederic
The use of less-sensitive energetic formulations for military training activities has driven the replacement of traditional explosive fills by a new generation known as Insensitive High Explosives (IHE). Due to their novelty, little is understood about their behaviour in the environment when deposited as part of a formulation, specifically how long they may persist and the likelihood of transport of significant concentrations to groundwater. However, it is impractical to empirically investigate the behaviour of IHE in all possible environmental conditions and scenarios, and as of yet, there is no single computational model that enables simulation of persistence of IHE in soil. Therefore, the aim of this thesis was to provide insight into the chemical behaviour of IHE to simulate their fate and transport in sandy soils. To achieve this, the key parameters governing IHE dissolution, transport through soil and degradation were identified, highlighting that the partitioning coefficient regulated IHE mobility through soil; rainwater pH modified IHE dissolution and soil temperature had a significant influence on IHE degradation. These parameters were used to develop a stochastic model able to simulate breakthrough times and concentrations in sandy soil environments. Comparison of simulated breakthrough concentrations of IHE to empirical soil columns proved that the model was able to representatively predict how IHE behaved in soil specifically concentration in leachate over time, which would be invaluable in evaluation of the environmental risks posed by IHE residues and to support soil remediation strategies in contaminated areas.
Open Access
Material strength evolution of FCC metals under high strain rates
(2020-12) Gilroy-Hirst, Caitlin; Hazael, Rachael; Wood, David; Akhavan, Jacqueline
Copper and stainless steel 21-6-9, two face-centred cubic (FCC) materials, were shock loaded in partially recovered uniaxial strain flyer-plate impact experiments at varying impact pressures (6 GPa - 16 GPa). These samples were collected post impact via three differing recovery configurations: (1) standard or ‘free boundary’; (2) partial shock recovery, i.e. using both ‘momentum trapping’ and ‘soft recovery’ techniques but with a flyer plate thickness of 10 mm to see the effects on partial tensile release in the rear spall plates of an established recovery target design; finally (3) a traditional full recovery comparison with a 2 mm flyer impact. These samples were then analysed using a suite of analytical techniques including X ray diffraction, optical microscopy, hardness testing and compression after impact testing, to observe the material deformation characteristics in the simplified partially recovered shock and release condition compared to the more complex ‘standard’ release wave situation. A control sample of a ‘ fully recovered’ sample was also carried out for comparative purposes. The rear spall plates were modified on these partially recovered samples to see the effect that this had on the tensile release waves and how this changed the material deformation properties overall. Results for the stainless steel 21-6-9 demonstrated the ability of the partial shock recovery technique (hereafter called ‘partial-recovery’) to mitigate the reverberations compared to that of the standard samples. Upon analysis of the targets, it was observed that the dislocation density was generally lower for the partially recovered samples but varied with impact pressure for both the standard and recovered configuration. For the stainless steel recovery experiments an increasing dislocation density from 4 x 1015 m-2 at 6 GPa to 6.5 x 1015 m-2 at 12 GPa was observed which then decreased to 5.5 x 1015 m-2 at 16 GPa. The twinning density to grain ratio obtained from optical microscopy showed a linear increase (y= 1.5345x - 8.3508) with an R2 value of 0.8295 from 7 GPa at 4 twins per grain to 17 twins per grain at 16 GPa. Twinning density is indicative of a successful recovery, where a successful recovery is a reduction in reverberations in the sample and in a full recovery is a 1D shock. The dataset both verifies the use and success of the recovery technique as well as demonstrating the materials characteristics under partial-recovery, while observing reverberation effects.
Open Access
“Round numbers are always false” – More EMIC (culturally contingent) than ETIC (universal)? Is national culture a defining facet of leadership in the defence and security sector?
(2021-06) Forgrave, Martyn W.; Watters, B
Leadership as a function in human groups is found in all corners of the world and can be traced by as far as the start of recorded history. Plato (428/429 BCE 348/347 BCE) was the first to write about the general attributes that determine leadership. This quest to identify traits that predict effective leadership continues to this day. Since the mid-twentieth century, scholarly attempts have been made to establish a universal theory of leadership that transcends cultural boundaries. Although the search for a definitive universal model has so far proved inconclusive, cross-cultural research continues to be focussed on determining whether aspects of leadership and leadership theory are “universal” (etic) or culturally contingent (emic) (i.e., unique to culture). The GLOBE project (2004), the most expansive and significant cross-cultural study to date, found that although leadership is culturally contingent, universal attributes of leadership exist. Although cross-cultural research on leadership has exploded in importance in the last twenty-five years or so, its existence is almost absent in all U.K. defence policy and doctrinal publications. Yet, the MOD’s policy position is to be “international by design” (MOD, 2018) and the recently published Integrated Review of Security, Defence, Development and Foreign Policy (MOD, 2021) signposts deepening defence and security international engagement over the coming decade. A critical review was conducted of selected academic and military literature on leadership, culture, and cross-cultural leadership. A research methodology was designed and developed to focus on a predominantly quantitative approach. This was driven primarily by the research question. However, this was offset by open questions to provide a qualitative element. Therefore, a mixed methods approach was used in this thesis. The research investigated prototypical leadership in sixteen countries across four continents. The cross-cultural research, focussed on equivalence and comparability, was carried out using seven regions as independent variables. The selection of the “middle manager” strata of leadership (Brigadier General to Major) provided functional equivalence. The questionnaire sample size was 1067. The survey included closed and open ended questions which were translated into Arabic, Georgian, Ukrainian, Burmese, Spanish and Korean. The main findings included the identification of twenty-five essential leader attributes that were considered essential across seven regions in the defence and security sector. The thesis failed to reject the null hypothesis that ‘effective leadership attributes, skills and traits in the defence and security sector are culturally contingent across countries and regions.’ The identification of a core of essential military leader attributes, demonstrating “partial universality”, was offset by wider findings that showed leadership in the defence and security sector to be culturally contingent across the sixteen countries. A cross-cultural prototypical military leadership model was constructed to provide a systematic and structured understanding of cross-cultural leadership and a means of cross-cultural comparability. The contextual model is based on seven leader dimensions encapsulating ‘personality and self’, ‘motives’, ‘cognitive capacities and skills’, ‘emotional capacities and social skills’, ‘integrity and moral character’, ‘team skills’ and ‘task skills’. Recognising that culture and leadership have a symbiotic relationship, in which one cannot exist without the other (Ayman & Korabik, 2010), the leadership construct is bound by culture at the micro (individual), meso (organisational) and macro (national) levels. Finally, the research makes a discrete contribution towards an etymological study of “leader” and “leadership” across cultures. An understanding of the etymology assists with the way we think about, study and enact leadership (Case et al., 2011). The findings show that a variance in semantics is indicative of cultural contingency. Notwithstanding this, there is sufficient similarity to permit a route scheme of meaning. Recommendations are made to investigate an expeditionary version of the GLOBE study (2004) questionnaire where data can be collected and collated efficaciously to contribute to the project from an organisational perspective. Further research should examine how the GLOBE study’s six global leadership dimensions can be applied to the defence and security sector. Follow-on work should also be carried out to understand the behavioural manifestations of identified attributes in the defence and security sector. This would make an important contribution to interoperability workstreams and multinational activities with allies and partners. A formal review is recommended to address the cross cultural deficit in U.K. Defence and that the doctrinal gap is closed in the re-write of Leadership in Defence (2004). More broadly, a more coherent approach should be taken between the defence proponents of leadership and culture. Recognising both the complexity and importance of cross-cultural leadership, the Ministry of Defence may wish to take forward the idea of trans-cultural alliances between leadership schools to promote information exchange and achieve a better understanding of indigenous military leadership constructs. Finally, a cross-cultural study into the leadership gender gap in the defence and security sector would provide a valuable research topic. This would advance the status of women in professional military forces as culture has been found to be an obstacle to gender egalitarianism, participation, and advancement in armed forces around the globe.
Open Access
Smurf : A reliable method for contextualising social media artefacts
(2020-02) David, Anne; Morris, S; Appleby-Thomas, Gareth J.
This research aims to evaluate whether artefacts other than the content of user com munication on social media can be used to attribute actions or relationships to a user. Social Media has enhanced the way users communicate on the Internet; providing the means for users to share content in real-time, and to establish connections and social relationships with like-minded individuals. However, as with all technology, social media can be leveraged for disagreeable and/or unlawful activities such as cyber bullying, trolling, grooming, or luring. There are reported cases where evidence from social media was used to secure convictions; for example, the tragic cases of Ashleigh Hall in 2009 and Kayleigh Haywood in 2015. The social media evidence e.g. the messages sent to the victim to arrange a meet up was used to link the suspect to the victim, and attribute actions to the suspect; in addition to other physical evidence presented as part of the case. Investigations with elements of social media is growing within digital forensics. This reinforces the need for a technique that can be used to make inferences about user actions and relationships, especially during a live triage investigation where the information needs to be obtained as quickly as possible. This research evaluates the use of live triage in the investigation of social media interactions, in order to determine the reliability of such a technique as a means of contextualising user activity, and attributing relationships or actions to a user. This research also evaluates the reliability of artefacts other than the actual content exchanged on social media; in the event that the content of communication is not immediately accessible/available to the investigator. To achieve this, it was important to break down the events that occur before, during and after user activity on social media; followed by the determination of what constitutes communication content in the context of this research. This research makes the following contributions: establishes a method for the cat egorisation of social media artefacts based on perceived user activity; communication content was characterised, thus highlighting evidential data of interest from user social media activity; the criteria for assessing the reliability of social media artefacts in a live triage investigation was proposed; a novel framework for social media investigation was developed with a Proof of Concept (PoC) to test its viability. The PoC demonstrates that it is possible to attribute actions or relationships to a user, using artefacts other than the actual content exchanged on social media.

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