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Item Open Access Boron Carbide-Silicon Carbide Nanocomposites for Next Generation Armour(Cranfield University, 2020-12-07 13:40) Payne, HenryMotivation for this Work:Modern warfare is developing rapidly; technology is becoming more advanced and the modern soldier requires more of it. With the increase in equipment there is an increase in weight which reduces mobility. Threats have also developed, in such environments greater protection can be required. Combining these two results in a need to produce lighter armour with a higher level of protection. Boron Carbide (B4C) has shown great potential for use in armours. It has a high hardness and low density, but unfortunately it sometimes fails prematurely. This has been explained by a phase transformation involving polytype collapse. This research aims to mitigate structural breakdown by microstructural design. It is hypothesised that a composite containing nano grains of B4C and Silicon Carbide (SiC) can mitigate the polytype breakdown, whilst combining the low density of B4C with the ballistic reliability of SiC.This poster will:• Outline the materials being investigated for use in new ceramic armours. Specifically those under investigation by Imperial College London, joint with DSTL• Give the breakdown of the method and aims of the project• Outline some basic results from initial studies. This will give the reader an idea of the final goal.Item Open Access External Security Guarantees and Their Impact on Civil War Termination(Cranfield University, 2020-12-07 14:03) Harvey, CraigCivil wars are notoriously difficult to terminate, with commitment problems increasingly seen as the primary cause for this failure. This research investigates the role that security guarantees and peace enforcement plays in overcoming these difficulties. It utilises linear regressions on a dataset including every civil war initiated between 1940 and 2007, and Cox Proportional Hazard models on a second dataset including every peace agreement between 1976 and 2008 along with case studies of Kosovo, Cote d'Ivoire and Liberia. Furthermore, it uses three different definitions, two of which drawn from the existing literature, to assess the impact of security guarantees. The results of the regressions show that a promise of a security guarantee is not as effective as a deployment of forces with a mandate to intervene and actively guarantee the existence of belligerents, and that where a leader is refusing to give up power, peace enforcement can be beneficial.Item Open Access Evaluation of Soil Health in Response to Insensitive High Explosive (IHE) Exposure(Cranfield University, 2020-12-07 13:50) Persico, FedericaSoil provides multiple important functions, such as provision of food and raw materials, a platform for urban development and human wellbeing and a filtering and transforming media for water, nutrients, and carbon. All these characteristics work together to ensure that the system functions efficiently as a living system. This functionality translates to a clear definition of soil health. The use of traditional explosives in various training areas has led to the contamination of soil with recalcitrant and persistent hazardous chemicals which can render the sites unusable and no longer accessible due to accumulation of these harmful energetic residues over time, having a great effect on soil health. New insensitive munitions, which have been designed to detonate on command and not accidentally, have been developed and are currently use in military operations and in training areas. These munitions are filled with insensitive high explosive (IHE) formulations which comprise of more stable explosive compounds, such as 2,4-dinitroanisle (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO) and 1,3,5-hexahydro-1,3,5-trinitrotriazine (RDX), whose behaviour and consequences in the environment in not yet fully understood. Therefore, a 155mm projectile filled with IHE has been detonated to investigate the spatial distribution and concentrations of explosive residues after a full-order detonation in a training area. The explosive concentrations found on site will be then replicated in a self-contained outdoor area to evaluate the consequences that the IHE has specifically on Soil Health. Leachate and plants will be analysed, plant growth monitored by comparison to several control beds and soil characteristics (e.g. pH, nutrients, oxygen), regularly tested. This will provide better understanding of the environmental consequences that IHE may have on soil health. In addition, results from this project will support future research in developing proactive risk assessment strategies for soil health.Item Open Access Bohmian Molecular Dynamics Simulations of Warm Dense Matter(Cranfield University, 2020-12-07 14:23) Campbell, ThomasThe computational demands of modelling large numbers of coupled electrons and ions have long been considered insurmountable, despite advances and refinements in density functional theory (DFT) calculations. However, a different approach to modelling quantum interactions, via application of the Bohmian trajectories formalism, can overcome this hurdle. We present further results from a new Bohm - molecular dynamics approach (Bohm MD). The static results of our simulations are validated by DFT results – our static ion-ion structure factor of aluminium at 5.2 g cm-3and 3.5 eV shows excellent agreement with both orbital free and Kohn Sham DFT. We then use Bohm MD to extract dynamic results, not only the ion-ion dynamic structure factor which provides a direct link to experimental observables, but also, unprecedentedly, the ion-electron and electron-electron dynamic structure factors.Thus Bohm MD provides a self-consistent approach to non-adiabatic investigation of dynamic modes in systems of thousands of particles.Item Open Access The Thermomechanical Behaviour of Carbon Fibre Reinforced Polymer in a Fire(Cranfield University, 2020-12-07 16:29) Aspinall, TimothyThe effect of fire on military aircraft is a large factor in assessing their survivability and understanding this is a complex and challenging task, which requires specialist research. Quantifying the thermomechanical behaviour of Carbon Fibre Reinforced Polymers (CFRP) used in aircraft structural components is an essential required step to determine their structural integrity when exposed to fire. The thermomechanical response leading to the loss of mechanical properties is governed by the glass transition, thermal decomposition (pyrolysis) of the resin matrix and oxidation of the carbon fibre reinforcement. These phenomena are strongly coupled and their effect on the mechanical response of CFRP are poorly documented in the literature.This work presents the development of a low-cost method for investigating the thermomechanical properties of such materials in terms of displacement and failure time under constant load. The work has centred on, an experimental study which is designed to quantify the thermomechanical behaviour of CFRP during three-point bending under different thermal exposures. Of particular interest was the contribution to the failure mechanism of the propagation of the glass transition isotherm through the sample and fibre oxidation on the exposed surface of the samples. Consequently, the results can be used to assess the understanding of failure modes of CFRP in loadbearing structural components of military aircraft.Item Open Access Interactive Methods for Improving Robustness of Neural Networks Against Adversarial Attacks(Cranfield University, 2020-12-07 14:10) McCarthy, AndrewNeural network based Machine Learning Systems are improving the efficiency of real-world tasks including, speech recognition, network intrusion detection, and autonomous vehicles. For example, network intrusion detection systems are well suited to machine learning, giving highly accurate classification. However, nefarious actors, ranging from lone hackers to advanced persistent threats seek to fool classifiers through influencing the output of the model. Unfortunately, most well trained neural network models may be fooled using gradient descent attacks algorithmically producing perturbed images known as adversarial examples.Bad actors wish to fool classifiers across application domains including Image recognition, speech recognition, and network intrusion detection. Humans and computers perceive the same data in different ways. Humans generally overlook minor differences in data. For example, minor changes in pixel size and colour. People easily overlook the visual difference between colour codes rgb(255,0,255) and rgb(254,0,254); whereas the numeric difference is strongly evident in computers algorithms, even within large quantities of data. Adversarial examples exploit this difference. Humans have difficulty detecting anything improper in a successful attack, because the perturbations are so small.Consequentially successful attacks against neural networks mean systems are vulnerable and therefore dangerously deployed in application domains. For example, incorrect classifications of road signs in autonomous could have dire consequences. Moreover, the increasing size of data being processed by neural networks enlarges the attack surface available to attackers whilst obfuscating the attack to humans. If unaddressed future mature attack methods will facilitate more destructive attacks. I therefore address the urgent research need in this area. My research explores the robustness of neural networks, aiming to understand the principles behind successful attacks and consider mitigations in key domains of network intrusion detection and image and speech recognition. I am designing tools to aid visualization of weak points in training datasets, and neural network models, to unearth attacks. Discovering ways to improve robustness of neural network models whilst retaining acceptable classification accuracy. Improving robustness of neural networks enables safe deployment across a wider range of domains.Item Open Access Breast cancer at the micrometre scale(Cranfield University, 2020-11-27 09:28) Gosling, SarahMicrocalcifications are deposits of calcium phosphate commonly found in association with some types of breast cancer. Calcifications are usually detected as bright white spots on a mammogram. Diagnosis of some breast diseases is linked to the morphology and distribution of microcalcifications, but these deposits are rarely investigated as individual entities.Multiple techniques have been used to investigate individual calcifications, including histological staining (H&E), scanning electron microscopy (SEM), elemental analysis (EDS) and x-ray diffraction (XRD). Together, these techniques allow a better understanding of the structure of the crystalline and tissue elements of breast calcifications at the micrometre scale, which may provide an insight in their formation mechanisms and possible functions. Ultimately, deciphering calcification chemistry could lead to their use as novel prognostic markers for breast disease.Item Open Access Defence and Security Doctoral Symposium Flyer 2020(Cranfield University, 2020-07-24 10:38) Cranfield UniversityFlyer promoting the Defence and Security Doctoral Symposium 2020.Item Open Access Capturing blast impact on helmets(Cranfield University, 2020-11-27 10:21) Bloodworth-Race, SusieWhen shielded from the fireball and fragmentation of an explosion, the blastwave can still cause multiple injuries, with increasing prevalence of Traumatic Brain Injury (TBI) noticed amongst survivors. Relatively low peak overpressures can result in Blast-Induced Mild TBI (bTBI), with significant deterioration in mental health manifesting as anxiety, behavioural changes, even loss of fine motor control, symptoms which can often be confused with Post Traumatic Stress Disorder (PTSD).The image shows a helmet blast impact from a compressed air shocktube, the resulting movement of head and helmet captured with high speed video. The moment of impact can be seen in the top sector with the shockwave captured as a vertical band of compressed air just behind the front of the head. The helmet is lifted, rotated backwards, held by the chinstrap and bounced back down onto the head, resulting in multiple possible mechanisms for bTBI.Item Open Access Structure of an Insensitive High Explosive formulation under a microscope(Cranfield University, 2020-11-27 10:07) Gutierrez Carazo, EncinaIMX-104 is an Insensitive High Explosive containing a mixture of 3-Nitro-1,2,4-triazol-5-one (NTO), 2,4- dinitroanisole (DNAN) and cyclotrimethylenetrinitramine (RDX). Due to its novelty, little is known about its potential toxicity and persistence in the environment and which has raised questions regarding its behaviour.Small flakes were placed under a Leica DM LM microscope to observe their microscopic structure and investigate the formulation process. The picture was taken using a ten times lense (10x) and reflected light. The scale shows the size of the flakes (in mm) and the fragments in focus were approximately 70 µm.Item Open Access When Multipetawatt Lasers Strike! The Physics and Applications of Laser Beams Hitting Solids(Cranfield University, 2020-12-07 16:34) Morris, StuartWhen we talk about extremely powerful lasers, it's easy to conjure up images of spies strapped to tables, Sci-Fi guns and planet destroyers, but facts are often stranger than fiction. Modern lasers on the intensity frontier are capable of focussing huge amounts of light energy into tiny, micron-scale focal spots over less than a trillionth of a second in duration - creating an incredibly high energy density. When such a pulse strikes something solid, we end up with a bright flash of X-rays, ion beams and even antimatter can be generated in the extreme fields - but how? And what applications can such exotic particles provide?Item Open Access Reflections and Their Real Space Significance(Cranfield University, 2020-11-27 10:01) Arnold, EmilyBone is a complex composite material made up of three main components, the most abundant of which is the mineral hydroxyapatite. Within many species, hydroxyapatite naturally occurs as a nanocrystalline material, making accurate analysis difficult. Brilliant X-ray sources are used to allow measurement of a much wider range of angular data (from Q = 0.05 to 60 Å-1) than a traditional laboratory X-ray diffractometer (from Q = 0.1 to 8 Å-1). Shown here is diffraction data collected at Diamond Light Source on the dedicated total scattering beamline I15-1. Debye-Scherrer rings can be seen, allowing measurement of crystallographic parameters within reciprocal space. Shadows are seen from the sample changer and an additional detector. This beamline allows for the observation of local coordination of atoms from 0.1nm to 5 nm (through pair distribution function analysis) while simultaneously measuring average crystallite structure.Item Open Access The Utility of Gait in Forensic Human Identification: An Empirical Investigation Using Biomechanical and Anthropological Principals(Cranfield University, 2020-11-27 12:06) Macoveciuc, IoanaForensic gait analysis is generally defined as the analysis of walking features of individuals from video footage, to assist in criminal investigations. Although an attractive approach to detecting suspects since data can be collected from a distance without their knowledge (e.g. from public CCTV cameras), this field of study currently lacks validation and quality standards not only due to insufficient research, but also because certain scientific foundations, such as the assumption of gait uniqueness, have not been adequately investigated. To test the scientific basis of this premise, a suitable dataset replicating an ideal forensic gait analysis scenario was compiled from the Karlsruhe Institute of Technology (Germany) database. Biomechanical analyses (i.e. joint angles) of human walking motion (i.e. gait cycles) in the left and right shoulder, elbow, hip, knee, and ankle joints of twenty participants was conducted using the R program. The purpose of these analyses was to investigate the degree to which differences between walking activities of the same participant (i.e. intraindividual variation) impact differences amongst participants (i.e. interindividual variation), according to the following aims: (1) to better understand the relationship between form (anatomy) and function (physiology) of human gait, (2) to investigate the basis of gait uniqueness by examining similarities and differences in joint angles, and (3) to build upon current theoretical foundations of gait-based human identification. The findings indicate different degrees of gait asymmetry given anatomical body region and gait sub-phase (i.e. component of a given cycle), thereby challenging previous methods employing interchangeable use of gait data irrespective of body side, and the use of ‘average’ gait cycles to represent the gait of an individual irrespective of body side. Furthermore, interindividual variability in all five joints is influenced by body side to different extents depending on gait sub-phase and body region, thereby challenging the claim of holistic uniqueness of gait features across all body regions and gait sub-phases. The results therefore underline that previously held assumptions may not hold true, and that their continued use irrespective of innumerable recommendations previously made and in light of novel research, may be detrimental to judicial situations where guilt or innocence is established based on such evidence. Given the findings of this research and paucity regarding empirical basis to support expertise, exerting caution when evaluating gait-based evidence admissibility in the courtroom is highly recommended, since the utility of gait in identification is currently limited.Item Open Access Board Games as a Behavioural Collection Method(Cranfield University, 2020-11-27 12:18) Sidorenko, TatjanaTraditionally, games have been viewed as a form of entertainment. Yet, given how engaging games can be their effects can be beneficial in many domains. This paper explores the use of games as a methodology of exploring the decision-making processes demonstrated by a group of information security specialists when role-playing as malicious actors.To achieve this a board game has been designed which enables players to impersonate different types of attackers each with different motivations and goals. Each player is given a set of tools, techniques and procedures (TTPs) in form of cards and a set of end goals which need to be achieved in order to ‘win’ the game. By interacting with the facilitator, who is also representing the defending organisation or location, they voice out their intended actions and decisions and play a TTP card of their choice. By adopting a persona in an engaging fictional setting players are freed from concerns associated with self-image maintenance and concerns about reputational damage and ultimately, are better able to construct creative and malicious attacks. The game methodology also provides a less limited framework for the data gathering, and with suitable facilitation allows the capture of a very diverse set of attacks.By using this methodology, it is possible to gather a more diverse set of both decision-making behaviour and attacks, improving our understanding of offensive actors. This understanding will then be used to influence the creation of an agent-based simulation of these actors and scenarios.Item Open Access Efficient Space-Time Finite Elements for Thermo-Mechanical Problems(Cranfield University, 2020-11-27 12:47) Quaine, KieranThis talk discusses efficient and reliable Finite Element Methods to simulate the thermo-mechanical response of high explosives. A key motivation is the modelling of the initiation of shear bands in materials such as HMX. The localised plastic deformation associated with a shear band leads to the formation of hot spots and can subsequently lead to thermal runaway. Standard finite element methods struggle to accurately resolve the sharp variations associated with these thermal and mechanical features which may lead to unphysical predictions of the numerical models. The numerical methods presented in this talk aim to provide efficient and reliable tools towards modelling the initiation of shear banding and thermal runaway. We consider two approaches: adaptively generated meshes based on mathematically rigorous estimates of the numerical errors, and enriched finite elements. They are illustrated for thermal and elastic problems, as they arise in reduced models. First, we present results based on adaptive finite elements for non-linear thermal problems. Steep temperature gradients are resolved by appropriate mesh refinement procedures. Steered by indicators for the accuracy of the solution, the algorithm automatically resolves hot spots on a refined mesh, significantly reducing computational costs, see for example [2]. Secondly, we con-sider enriched space-time finite elements (also known as generalised finite elements) which include a priori physical information into the numerical method. This a priori information could represent localised of wave-like features, which are added to a coarse approximation space. The modelling can effectively capture features occurring at different spatial and temporal scales [4, 5]. Here we consider a first order formulation of the wave equation [1] and choose plane-wave enrichments [6]. Future work aims to address the full, coupled thermo-mechanical system, as well as to combine the adaptive and enriched approaches of Iqbal et al. [3].[1] H. Barucq, H. Calandra, J. Diaz, and E. Shishenina. Space-Time Trefftz - Discontinuous Galerkin Approximation for Elasto-Acoustics. (RR-9104), 2017.[2] Heiko Gimperlein and Jakub Stocek. Space–time adaptive finite elements for nonlocal parabolic variational inequalities. Computer Methods in Applied Mechanics and Engineering, 352:137 – 171, 2019.[3] M. Iqbal, D. Stark, H. Gimperlein, M.S. Mohamed, and O. Laghrouche. Local adaptive q-enrichments and generalized finite elements for transient heat diffusion problems. Computer Methods in Applied Mechanics and Engineering, 372:113359, 2020.[4] O. Laghrouche, P. Bettess, E. Perrey-Debain, and J. Trevelyan. Wave interpolation finite elements for Helmholtz problems with jumps in the wave speed. Computer Methods in Applied Mechanics and Engineering, 194(2):367 – 381, 2005.[5] E. Perrey-Debain, J. Trevelyan, and P. Bettess. On wave boundary elements for radiation and scattering problems with piecewise constant impedance. IEEE Transactions on Antennas and Propagation, 53(2):876–879, 2005[6] Steffen Petersen, Charbel Farhat, and Radek Tezaur. A space–time discontinuous galerkin method for the solution of the wave equation in the time domain. International Journal for Numerical Methods in Engineering, 78(3):275–295, 2009Item Open Access Critical Incident Decision-Making: A systematic review of the barriers, processes and frameworks(Cranfield University, 2020-11-27 14:00) May, BrandonCritical incidents are environments that can be characterised by complexity, high-stakes, ambiguity, time-urgency and uncertainty, and often involve a multi-agency response (e.g. Fire and Rescue, Police, and the Military); for example, in terror attacks (e.g. Manchester bombings, London Bridge), fire disasters (e.g. California wildfires, Grenfell Towers), and the 2020 COVID-19 pandemic. In this respect, critical incidents are distinctive, dynamic events in which multi-agency systems lack the situational awareness and operational experience to make effective strategic and tactical decisions. Whilst research has begun to understand and explore decision-making in complex environments, there is limited research that focuses on understanding the processes used to coordinate effective responses in situ within critical incident environments; specifically, critical incident decision-making. This review sought to (i) identify relevant studies, (ii) critically appraise concepts that relate to the central theme of critical incident decision-making in-situ, and (iii) examine the barriers that compound effective strategic and tactical decision-making. The research identified numerous factors that affect the decision-making process (e.g. political agendas, disparity between operational objectives, and intra-and-inter agency collaboration). Additionally, several theoretical and applied decision-making frameworks were identified (e.g. Joint Decision Model; JESIP), that to date, have not factored in how complex, high-stake multi-agency decisions are made under conditions of uncertainty and time-urgency. This presentation will discuss the theoretical implications across security, defence, and law enforcement contexts and present pathways for future research.Item Open Access Development of a Smart Sniffer Device for the Detection of Illicit Drugs, Homemade Explosives, and their Precursor Chemicals(Cranfield University, 2020-11-30 13:29) Hardy, IonaThe controlled drug market in the UK alone is worth £9.4 billion a year (£19 billion a year cost to society) and is used to finance other crimes, including terrorism with enormous social-economical costs. The threat continues to change and exploitation of the latest scientific and technical advances to enhance operation capabilities for an early detection of terrorist and criminal activities, is at the core of Law Enforcement Agencies (LEAs) operational requirements. Among the detection technologies currently used/explored by UK and International market, a portable sniffer device that can detect multiple illicit substances, in a non-destructive, rapid, and accurate manner, would offer a valid alternative to LEAs.The CRIM-TRACK sniffer device was developed by Cranfield and Danish Technical University (EU FP7 project) and is currently at TRL 4. See attached file for the full abstract.Item Open Access Temperature Dependent Toxin Expression in Bacillus Cereus G9241, the Causative Agent of Anthrax like Illness(Cranfield University, 2020-11-27 14:51) Manoharan, ShathvigaBacillus cereus G9241, a member of the Bacillus cereus sensu lato complex, was isolated from a Louisiana welder with a pulmonary anthrax-like illness and is closely related to B. anthracis. Most members of the B. cereus group express PlcR, a pleiotropic transcriptional regulator of secreted toxins and enzymes allowing insect infection, which is activated by the peptide PapR at stationary phase of growth. However, in all B. anthracis isolates, the plcR gene contains a point mutation, which frame-shifts the gene, thus inactivating it. It has been proposed that the acquisition of AtxA, the mammalian responsive transcriptional regulator, was incompatible with the activity of PlcR, leading to selection for PlcR inactivation. Interestingly, G9241 encodes intact copies of both atxA and plcR. Preliminary data has shown that B. cereus G9241 has a temperature dependent haemolytic activity, possibly caused by haemolysins that are regulated by PlcR. We hypothesise that a change in the PlcR-PapR regulatory network in G9241 has allowed the co-existence of plcR and atxA through temperature dependent suppression of the PlcR-PapR circuit at the time AtxA becomes active.Here we investigated whether the activity of the PlcR-PapR circuit and PlcR regulated toxins in B. cereus G9241 are temperature dependent (25 °C and 37 °C), in order to accommodate the activity of AtxA. Plasmid based transcription-translation GFP reporter of PlcR, PapR and PlcR-regulated toxins have been used to study translational activity.Item Open Access Assessing the suitability of highly filled energetic composites for additive manufacture(Cranfield University, 2020-11-27 14:40) O'Donnell, MichaelThere is currently significant interest in the development of additive manufacturing (AM) techniques suitable for various energetic materials, such as explosives and propellants. One potential approach in this application space is to use extrusion-based techniques, such as Direct Ink Writing (DIW), to print highly solids filled pastes based upon uncured polymer bonded explosives (PBXs) or composite propellants. In supporting the development of these techniques, it will be important to develop an understanding of how the rheological properties of the materials affect their overall printability, which can be defined as their suitability for a particular AM approach. Such an understanding could enable rapid selection and optimisation of suitable technologies or formulations based upon measurable parameters.This paper reviews the printability of energetic materials in extrusion-based systems, and considers applicable approaches, rheological models and experimental techniques. The design, assembly and testing of custom apparatus for assessing the extrusion properties of an energetic paste are also discussed.Item Open Access Probing the Structure and Evolution of Anode Materials in Thermal Batteries(Cranfield University, 2020-11-30 13:39) Azad, AtiaHigh-temperature thermal batteries use lithium-silicon alloys as the anode material. Li13Si4, Li7Si3 and Li12Si7 alloys are studied to determine if phase transitions occur or if the alloys become amorphous between room temperature and 500◦C (the typical operating temperature of thermal batteries). These alloys are synthesised by reacting lithium metal and silicon powder at elevated temperature inside an evacuated quartz ampoule. The samples’ structural changes are investigated at elevated temperatures using in situ powder neutron diffraction. This is carried out on the Polaris diffractometer at ISIS facility, Rutherford Appleton Laboratory, UK. The results of the neutron scattering experiment seem to imply that the alloys do not become amorphous at 500◦C and no phases transitions occur in the temperature range. Further work is required to determine if phase transitions occur below room temperature. The work so far has presented a simple method of synthesising these alloys and gives information on the lack of phase transitions between room temperature and 500◦C.