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Item Open Access 4D Printing of Magnetic Shape Memory Alloys(Cranfield University, 2020-12-02 11:40) Milleret, AnastassiaMagnetic shape memory alloys (MSMA) are ferromagnetic materials exhibiting a plastic reversible transformation. Compared to thermally activated shape memory alloys, such as NiTi, the response of MSMA is much faster (less than a millisecond), making them good candidates for actuators, sensors, micro pumps and energy harvesters. To date, the Ni-Mn-Ga system is the most studied MSMA, and is the focus of this study. The shape memory effect in MSMA is driven by a phase transformation from a high ordered austenitic Heusler phase to a lower symmetry martensitic phase. The change in the shape occurs within the martensitic phase in the presence of a magnetic field. This is due to the reorientation of the twin variants. The best magnetic shape memory effect was reported in single crystalline Ni-Mn-Ga exhibiting up to 10% strain. However, in the polycrystalline form, grain boundaries create obstacles for twin boundary motion and thus the shape memory effect is reduced. Nevertheless, recent studies show a high magnetic-field induced strain, up to 8.7%, in polycrystalline Ni-Mn-Ga foams. Increasing porosity and grain size decreases the grain boundary constraint. MSMAs foams can be made using ceramic space holders, by binder-jetting or by ink-printing. However, these techniques create random distribution and/or size porosity. Further investigations are required to control porosity and grain morphology to enhance the shape memory effect. In addition, magnetic properties are orientation-dependant. Previous studies have reported the possibility to control the grain orientation via laser-powder bed fusion (l-PBF) additive manufacturing technique by tuning the printing parameters and the scanning strategy. Thus, l-PBF appears to be a potential approach to create near-net shape oligocrystalline and foam-structure Ni-Mn-Ga.Item Open Access ASP Triangles: Sketching the Artificial Intelligence of a Mobile Platform(Cranfield University, 2020-12-01 08:49) Di Fraia, MarcoASP triangles are a tool that we introduced to structure the design process of the on-board Artificial Intelligence (AI) of a mobile platform. Their value lies in taking into account the couplings and interactions between macroelements characterizing the platform and the mission context, in analogy to the paradigm shift introduced in aerospace structures by the development of aeroelasticity.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 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 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 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 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 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 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 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 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 Direct Temperature Measurements in Solids via Inelastic X-Ray Scattering Under Shock and Ramp Compression(Cranfield University, 2020-12-01 08:42) Karnbach, OliverShock and quasi-isentropic compression of solid-state matter via laser-ablation affords the creation of high energy density states of matter, with pressures and temperatures of relevance to core conditions within planets in our own solar system and beyond. Crystallographic phase and density can be discerned via ultra-fast x-ray diffraction, whilst pressure is deduced from VISAR measurements. Temperature is more difficult to determine, but techniques based on inelastic scattering from phonons are being considered [1]. It is in this context that we present here multi-million atom molecular dynamics simulations of the phonons present in fcc crystals shocked beyond their elastic limit. Despite high dislocation densities behind the shock front, distinct phonon modes can still easily be discerned, though such defects do contribute to the quasi-elastic peak that will compete with any inelastic scattering signal in a real experiment. Changes in the dispersion curves due to compression and the high number of stacking faults can also be observed.[1] E.E. McBride et al., Rev. Sci. Instrum. 89, 10F104 (2018)For full abstract, see attached file.Item Open Access Dissolution Rates of Chemical Components of an Insensitive High Explosive Formulation(Cranfield University, 2020-11-27 14:14) Gutierrez-Carazo, EncinaThe need of insensitive munition has driven the replacement of traditional explosives by Insensitive High Explosives (IHE), less sensitive to external stimuli. This new generation contains compounds such as 2,4-dinitroanisole (DNAN) and 5-nitro-1,2,4-triazol-3-one (NTO) that have different psyco-chemical properties, making them more labile and mobile through the environment. However, little is known about the persistence and toxicity of these chemicals once released in the environment and this raises the challenge on how they can be assessed for human exposure. Accelerated laboratory experiments such as soil columns or bottle flask have being addressing the problem, although they can be time consuming, expensive and results cannot be extrapolated to different environments. Computational modelling can help to overcome this issue, as it allows the simulation of fate and transport of explosive compounds in the environment under a different insight. Nevertheless, the simulations and predictions made with this approach are not representative enough and they require inputs that can only be obtained experimentally. Additionally, there are extra problems when assessing explosive impact in soil as it is a heterogeneous matrix and it varies over time and studied area. Therefore, the aim of this study is to develop a representative computational model to inform the fate, transport and persistence of IHE compounds in the environment. For that, GoldSim, a simulation software has been chosen due to its flexibly on modelling and due to the possibility of adding stochastic simulations, which are able to better understand and model uncertainties. The model will be used to assess environmental risks of explosives and to help remediation strategies.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 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 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 Generative Adversarial Networks for X-Ray Computed Tomography(Cranfield University, 2020-11-30 17:09) Valat, EmilienX-Ray computed tomography is a widely used, non-destructive imaging technique that produces cross-sectional images of bodies sensitive to X-Ray. Inter alia, it relies on exhaustive sampling of the attenuation properties of the scanned material and advanced reconstruction processes. However, acquisition can be toxic for humans or limiting for exotic geometries, as intense X-Ray exposure can lead to cancers during in-vivo diagnosis and experiments chambers have a fixed size that might limit the information gathering process for certain objects. Since sparse data from incomplete scans is yet to be compensated by adequate aftertreatment, we have decided to use deep-learning techniques to extract information on additional modalities to generate missing data in the acquisition.In many routine diagnoses, prior knowledge about the scanned object is often known. Whether it is computer-assisted design drawings or anatomical models, the availability of information regarding the shape of the test sample has led us to look for an acquisition process that minimises object sampling and maximises data harnessing on a known modality. After an introductory period of looking for the suitable architecture and publishing negative results, our exploration of deep generative models has led us to a unique design, one that combines unsupervised feature extraction with graphical models, use of these features for image generation with likelihood-free networks and a constrained optimisation problem to generate high-resolution acquisitions. This model translates our optimal understanding of the problem and an initial analysis suggests the feasibility of our process. Should the concept be promising, many challenges are yet to be addressed: accurate database constitution, efficient training items generation, thorough hyperparameters optimisation and delicate experimentations. As such, these are the next milestones in this investigation. Over the course of the next year, we are determined to deliver a method that is not only novel, but useful to many research fields.Item Open Access Identity Based Consensus for Self-Governing Systems(Cranfield University, 2020-11-30 16:26) Platt, MoritzThe selection of members is a challenge in decentralised record-keeping systems. In ‘permissioned’ systems, this crucial task is performed by a central authority or consortium. In ‘permissionless’ systems, however, the selection process is not trivial and comes with risks. Malicious actors, in a privileged position, can tamper with data, threatening the integrity of the system as a whole. Permissionless membership selection protocols, popularised with the dissemination of distributed ledger technology, have the objective of limiting the influence of a single entity on the wider network.They do so by approximating a participant’s legitimacy, to participate in record maintenance, through external or internal factors. These approximations come with downsides, in terms of attackability, system performance, supported use-cases and resource requirements. In this poster, I propose a prototypical membership selection protocol that uses the measure of personhood as an approximation of legitimacy. Interpreting a decentralised system as a political system, I frame the membership selection problem as one of political representation. I propose a protocol that democratically attributes a personhood score to members, thus creating a self-governing public decentralised system.This work in progress lays out a roadmap for the formal evaluation of self-governing public decentralised systems and describes the anticipated challenges in their implementation.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 Meteorological Wind Effect on the Ballistic Trajectory of a Medium Calibre System(Cranfield University, 2020-12-02 10:52) Knight, DanielModern systems use a single wind sensor onboard the vehicle to measure and capture meteorological wind data to calculate a weapon systems ballistic offset. The most calculations assumes constant wind between firing point and target for the offset. Meteorological wind is not constant being effect by wind gradient, terrain height and other surface changes. Using trial and test data from multiple wind sensors on a firing range, the wind can be modelled across the full flight of a rounds trajectory. Using modelling and analytical approaches to test known and experimental theories around meteorological wind offset to ballistic trajectory. The modelling provides a cost effective approach alongside practical real data from testing.