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Item Open Access The Lake Paravani archive – a contribution to the late Quaternary landscape evolution of the Lesser Caucasus (Georgia)(Wiley, 2024-07-01) Gademann, Daniel; Ustiashvili, Nino; Adikashvili, Luka; Navrozashvili, Levan; Erb-Satullo, Nathaniel L.; van der Meij, W. Marijn; Kirkitadze, Giorgi; Koff, Tiiu; Elashvili, Mikheil; Brückner, Helmut; Laermanns, HannesLake Paravani, located on the volcanic Javakheti Plateau in the central part of the Lesser Caucasus at 2073 m a.s.l., forms a unique geo-bio-archive for palaeoenvironmental reconstructions in this remote region. Based on sediment cores from the southwestern part of the lake we expand the existing palynological and sedimentological records beyond the Last Glacial Maximum (LGM). For the first time, it is possible to reconstruct the palaeoenvironment in this part of the Lesser Caucasus back to c. 28 cal. ka BP. Our study shows that until 16 cal. ka BP glacial conditions dominated (Phase I) in the region; there is, however, proof that the lake already existed during the LGM. In the following transitional Phase II from 16 until 6 cal. ka BP, cold and arid conditions with sparse steppe vegetation and a lowered lake level prevailed. Around 10 cal. ka BP, tree pollen started to expand while herbaceous pollen, especially Chenopodiaceae, declined. In Phase III, since 6 cal. ka BP, mixed forest probably represented the Holocene climatic optimum. Fluctuating lake levels indicate shifting climatic conditions. The minor changes of arboreal pollen hin the uppermost part of Phase II may be an indication of human activity. The more humid, vegetation-rich environment and mild climate around 4.5–2 cal. ka BP correlate with the expansion of the Late Bronze Age settlements in this area (from ~3.5 cal. ka BP/~1.5 ka BC). The proliferation of sites on the plateau, along with even higher-altitude sites possibly dating to the same period, may indicate that this climate amelioration played an important role in enabling more sustained human occupation. The results extend the record on Lake Paravani by several millennia beyond the LGM and complement the palaeo-lake reconstructions of the wider region, e.g. at Lake Van (Türkiye) or Lake Sevan (Armenia).Item Open Access CCS0025: Written evidence for the Environmental Audit Committee of the UK Parliament in relation to climate change and security(UK Parliament. House of Commons Select Committee. Environmental Audit Committee, 2024-05-15) Wilkinson, Edith; Morrell, KevinItem Open Access Resolving full-wave through-wall transmission effects in multi-static synthetic aperture radar(IOP Publishing, 2024-07-09) Watson, Francis; Andre, Daniel; Lionheart, W. R. B.Through-wall synthetic aperture radar (SAR) imaging is of significant interest for security purposes, in particular when using multi-static SAR systems consisting of multiple distributed radar transmitters and receivers to improve resolution and the ability to recognise objects. Yet there is a significant challenge in forming focused, useful images due to multiple scattering effects through walls, whereas standard SAR imaging has an inherent single scattering assumption. This may be exacerbated with multi-static collections, since different scattering events will be observed from each angle and the data may not coherently combine well in a naive manner. To overcome this, we propose an image formation method which resolves full-wave effects through an approximately known wall or other arbitrary obstacle, which itself has some unknown 'nuisance' parameters that are determined as part of the reconstruction to provide well focused images. The method is more flexible and realistic than existing methods which treat a single wall as a flat layered medium, whilst being significantly computationally cheaper than full-wave methods, strongly motivated by practical considerations for through-wall SAR.Item Embargo Characterisation and fragmentation of brass and copper pipe bombs when using different initiation locations(DEStech Publications, 2023-12-31) Plagge, Nina; Harris, Mike; Painter, JonathanThe fragmentation characteristics of pipe bombs made from copper and brass, filled with a single base propellant, and initiated with an electric match positioned either at the end or halfway along the pipe were studied. A rig was devised to negate any variation from the effectiveness of end caps. Fragments were captured in strawboard packs and recovered to enable imaging and Fragment Weight Distribution Mapping (FWDM) graphs. The position of the initiator had a measurable effect on the fragmentation of the copper pipe, with the middle-initiated pipes having a higher relative power. In contrast, no such clear link was evident for the brass pipes. This likely indicates that the initiator location has less of an effect in stronger materials which are able to confine the propellant prior to rupturing.Item Open Access Modified Arrhenius kinetics for double base propellant decomposition: effect of water(Elsevier, 2024-05-31) Romero Jabalquinto, Alonso; Mai, Nathalie; Belghiche, Samira; Gill, Philip P.Numerous studies have been conducted on the decomposition mechanisms of cellulose nitrate (NC), a polymer employed in double base (DB) rocket propellants. It is well known that storage temperature affects the lifetime of these energetic formulations. However, less studies have been published on the influence of water. This research examined the role of water on the stabiliser consumption rate during accelerated ageing of a DB rocket propellant, as well as the impact on the shelf life prediction of the energetic formulation. Different volumes of water (0.8, 1.6, 2 and 4 µl/g) were added to the propellant in sealed vials, which were then isothermally aged (70, 80, 90, 100 °C). Analyses of the stabiliser consumption showed a faster decomposition kinetics in presence of water which is indirectly linked to the shortening of the storage life of the NC based propellant by 35 %. For the conditions, an activation energy of 133 ± 4 kJ/mol was reported for the water catalytic decomposition mechanism. A numerical model that included water as a variable was reported to reduce the uncertainty in the determination of the service life of NC based propellant. International standards such as Allied Ordnance Publication 48 should not overlook the effect of water/moisture on the safety of ammunition containing NC and should implement a modified Arrhenius equation.Item Open Access Guest editorial: Climate Neutral Supply Chains(IEEE, 2024-04-30) Mukandwal, Prabhjot; Guntuka, Laharish; Aktas, EmelItem Open Access Combined intensity and coherent change detection with four classes for laboratory multistatic polarimetric synthetic aperture radar(Institution of Engineering and Technology (IET), 2024-06-14) Hagelberg, Alexander; Andre, Daniel; Finnis, MarkSatellites and drone swarms can be used to collect multistatic Synthetic Aperture Radar (SAR) images. Synthetic Aperture Radar images can be used for Intelligence Surveillance and Reconnaissance. One method is to use Coherent Change Detection (CCD) to identify changes such as objects or tracks in the scene. This paper investigates a two-stage change detector, formed using intensity change and CCD images, extended to laboratory measured multistatic SAR data. A variety of performance metrics are used to quantitatively assess the results. Bistatic results are compared to a variety of multistatic and fully polarimetric results. The improvement in performance of multistatic and fully polarimetric images over bistatic images is shown. Additionally challenges and limitations of using multistatic datasets are highlighted.Item Open Access Shaping the structure and properties of HyTemp using polyethylene glycol diglycidyl ether cross-linkers(Wiley, 2024-06-03) Dossi, Eleftheria; Mutele-Nkuna, Khuthadzo Lourate; Wilkinson, Peter; Kister, Guillaume; Patrick, Hugh; Khalili, Mohammad Hakim; Hawi, SaraNovel elastomers are made by reaction of hydroxyl-terminated polyacrylic ester (HyTemp) with polyethylene glycol (PEG, number of ethylene glycol units 1, 3, 6, 9) based cross-linkers. The influence of the cross-linker length, the HyTemp/cross-linker (w/w) ratio and the cross-linking accelerator trifluoromethanesulfonate scandium salt (ScTFMS) on the structure and the properties of the materials are studied. The cross-linker length has not influence on the glass transition (Tg) of the products because of the presence of the flexible PEG units that cancels out the cross-linking effect associated to a shift to higher Tg. A two-domain structure is seen by the presence of a dual Tg in samples cured with ScTFMS. Mathematical analysis of the modulated differential scanning calorimetry curves offers for the first time the possibility to identify/confirm structural differences in complex three-dimensional polymeric structures. Scanning electron microscopy and swelling experiments in ethyl acetate respectively reveal an increase in the pore size (1.13 to 5.48 nm) and in the absorption ability of the elastomers cured with different types and quantities of PEG cross-linker. The new elastomeric materials are exhibiting a rubbery state over a wide temperature range and absorptivity for the potential recovery of pollutants in soil and/or water.Item Embargo Are two bodies in a trench a mass grave? an attempt to bridge the gap between single and mass graves(Equinox Publishing, 2024-03-27) Wessling, Roland; Spoletini, AllieThe definitions for mass graves proposed in the past concentrated on the minimum number of casualties and whether they were in a connected body matrix. This meant that many graves practitioners encounter could not be classified properly. They were neither a single grave nor a mass grave. This article proposes four key measures to address the grave classification issue. Firstly, it introduces three simple criteria to assist in classification. Secondly, it suggests three new grave types (cluster, trench, and serial grave) to name the most common graves. Thirdly, a final grave type, the multiple grave, is added to describe any grave that does not fit into any of the other categories. Finally, this article suggests that the threshold between multiple and many casualties, i.e. how many casualties constitutes a mass grave, should be set for each individual conflict or context rather than aiming for a universal figure. These four measures are designed to be simple, intuitive and flexible enough to allow practitioners to use grave labels that make sense in their particular context for forensic and legal professionals as well as the general public.Item Open Access Enhanced hyperspectral sharpening through improved relative spectral response characteristic (R-SRC) estimation for long-range surveillance applications(MDPI, 2024-05-29) Yuen, Peter W. T.; Piper, Jonathan; Yuen, Catherine; Cakir, MehmetThe fusion of low-spatial-resolution hyperspectral images (LRHSI) with high-spatial-resolution multispectral images (HRMSI) for super-resolution (SR), using coupled non-negative matrix factorization (CNMF), has been widely studied in the past few decades. However, the matching of spectral characteristics between the LRHSI and HRMSI, which is required before they are jointly factorized, has rarely been studied. One objective of this work is to study how the relative spectral response characteristics (R-SRC) of the LRHSI and HRMSI can be better estimated, particularly when the SRC of the latter is unknown. To this end, three variants of enhanced R-SRC algorithms were proposed, and their effectiveness was assessed by applying them for sharpening data using CNMF. The quality of the output was assessed using the L1-norm-error (L1NE) and receiver operating characteristics (ROC) of target detections performed using the adaptive coherent estimator (ACE) algorithm. Experimental results obtained from two subsets of a real scene revealed a two- to three-fold reduction in the reconstruction error when the scenes were sharpened by the proposed R-SRC algorithms, in comparison with Yokoya’s original algorithm. Experiments also revealed that a much higher proportion (by one order of magnitude) of small targets of 0.015 occupancy in the LRHSI scene could be detected by the proposed R-SRC methods compared with the baseline algorithm, for an equal false alarm rate. These results may suggest the possibility of SR to allow long-range surveillance using low-cost HSI hardware, particularly when the remaining issues of the occurrence of large reconstruction errors and comparatively higher false alarm rate for ‘rare’ species in the scene can be understood and resolved in future research.Item Open Access Alternative bootstrap confidence regions for multiple correspondence analysis(Taylor & Francis, 2024-05-07) Ringrose, Trevor J.A new approach for constructing elliptical bootstrap confidence regions for Multiple Correspondence Analysis is proposed, where the difference in method follows directly from the adoption of a different objective criterion to previous approaches. This includes a new correction for the well-known problems caused by the diagonal of the Burt matrix. Simulation experiments show that the method performs reasonably well in many cases, with exceptions being noted. Simulated data sets with known structure are also used to illustrate cases where the proposed method produces results in line with what would be expected, but some alternatives do not.Item Open Access Comparing historic military capabilities: apples with apples(Taylor & Francis, 2024-05-07) Fisher, RichardUsing comparative historical analysis to compare and contrast historic military capabilities is possible using the Defence Lines of Development as a model. Richard Fisher demonstrates how it is not appropriate to merely compare technical aspects of equipment, but that it is necessary to also consider the training, personnel, information, doctrine and concepts, organisation, infrastructure and logistics as part of a comprehensive comparison. Equipment comparisons exist but are flawed as they may not identify the critical factors that enhance or diminish the overall capability. The method is evaluated using the infantry section’s machine guns of the Second World War: the Bren and MG42.Item Open Access A comparison of far-field explosive loads by a selection of current and emerging blast software(Sage, 2024-04-29) Chester, Alastair; Critchley, Richard; Hazael, RachaelIn blast resistant design, simulation data may be used to generate the explosive loads that would be witnessed by the detonation of a high explosive device. There are many software packages available to simulate explosions, and this study aims to provide a comparison of a selection of them, including some recently available, with the aim of forming an understanding of the potential accuracies and speed of these in far-field explosive prediction. Software selection criteria were formed by a literature survey to highlight the commonly commercially used programmes. Each software package was used to predict the far-field effects of overpressure and specific impulse from two explosive charges against a reflective target. The data generated by these simulations were then critically compared and reviewed, both with respect to each other and, for the 100 kg charge size, with respect to experimental data. It shows that for the simulated scenarios, after domain and cell size fidelity studies have been performed, the choice of software may lead to a variance in prediction in the peak overpressure of up to 50%, specific impulse of up to 15%, and simulation run times by a factor of 600.Item Open Access Synthesis, structure characterization, Hirshfeld surface analysis, and computational studies of 3-nitro-1,2,4-triazol-5-one (NTO):acridine(Springer, 2024-04-30) Şen, Nilgün; Pons, Jean-François; Zorlu, Yunus; Dossi, Eleftheria; Persico, Federica; Temple, Tracey; Aslan, Nazife; Khumsri, AkachaiTo modify the physical features and extend applications of the 3-nitro-1,2,4-triazol-5-one (NTO), we synthesized NTO with acridine (ACR) at a molar ratio of 1:1, a neutralization reaction. Through altering the chemical composition, it was possible to alter physical properties such as thermal stability, free space (voids), packing coefficient, crystal density, difference in pKa of co-formers, morphology, solubility, and impact sensitivity, and detonation parameters . It appears that physical attributes could be entirely altered. Single-crystal and powder X-ray diffraction methods, infrared spectroscopy, mass spectrometry, nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR), and thermal analysis were utilized to comprehensively characterize and confirm the formation of the structure of NTO:ACR. The substantial hydrogen bond interactions and planar layered structures observed between the cations and anions generated a complex 3D network, providing insight into the structure–property interrelationship. One intriguing feature discovered is the layered structure present in NTO:ACR, which may be responsible for the low impact sensitivity. According to the experimental results, NTO:ACR showed good thermal stability (Td = 229 °C) and outstanding impact sensitivity (IS = 100 J). Detonation velocity and pressure were calculated using the EXPLO5 software program and found to be 7006 m·s−1 and 20.02 GPa, respectively.Item Open Access Indirect tuning of a complementary orientation filter using velocity data and a genetic algorithm(Taylor and Francis, 2024-04-23) Maton, Dariusz; Economou, John T.; Galvão Wall, David; Khan, Irfan; Cooper, Robert; Ward, David; Trythall, SimonIn this paper, the accuracy of inertial sensor orientation relative to the level frame is improved through optimal tuning of a complementary filter by a genetic algorithm. While constant filter gains have been used elsewhere, these may introduce errors under dynamic motions when gyroscopes should be trusted more than accelerometers. Optimal gains are prescribed by a Mamdani fuzzy rule base whose membership functions are found using a genetic algorithm and experimental data. Furthermore, model fitness is not based directly on orientation but the error between estimated and ground truth velocities. This paper has three interrelated novel elements. The main novelty is the indirect tuning method, which is simple, low-cost and requires a single camera and inertial sensor. The method is shown to increase tracking accuracy compared with popular baseline filters. Secondary novel elements are the bespoke genetic algorithm and the time agnostic velocity error metric. The contributions from this work can help improve the localization accuracy of assets and human personnel. This research has a direct impact in command and control by improving situational awareness and the ability to direct assets to safe locations using safer routes. This results in increasing safety in applications such as firefighting and battlespace.Item Open Access A multidisciplinary investigation of a mummified Egyptian head and analysis of its associated resinous material from the Salinas Regional Archaeological Museum in Palermo (Sicily)(Elsevier, 2024-04-13) Squires, Kirsty; Davidson, Alison; Cooper, Simon; Viner, Mark; et al.Among the 70 items donated by the abbot Antonio Pietro Paternostro to the former National Museum of Palermo (now Salinas Regional Archaeological Museum) in 1870, an ancient Egyptian mummified human head stands out. In 2022 the finding was submitted for a multidisciplinary investigation that relied upon non-invasive or minimally invasive approaches. Investigations revealed that this is a possible female head, which was likely subjected to trans-nasal craniotomy, and dated to the Egyptian Graeco-Roman period. The head was packed with an abundant amount of resin which was analysed using thermogravimetric analysis, infrared spectroscopy, and gas chromatography with mass spectrometry. The analysis suggested that the resin was most likely comprised of a natural resin, pitch, or tar, from the Pinaceae family of conifers, and mixed with other materials including a fat, oil, or wax. The use of multiple sample preparation techniques for the chromatographic analysis provided a high level of confidence in the identification of a wide variety of compounds, including a range of himachalene derivatives, which indicate the inclusion of cedar tar or oil.Item Open Access A template for creating and sharing ground truth data in digital forensics(Wiley, 2024-04-21) Horsman, GraemeGround truth data (GTD) is used by those in the field of digital forensics (DF) for a variety of purposes including to evaluate the functionality of undocumented, new, or emerging technology and services and the digital traces left behind following their usage. Most accepted and reliable trace interpretations must be derived from an examination of relevant GTD, yet despite the importance of it to the DF community, there is little formal guidance available for supporting those who create it, to do so in a way that ensures any data is of good quality, reliable, and therefore usable. In an attempt to address this issue, this work proposes a minimum standard of documentation that must accompany the production of any GTD, particularly when it is intended for use in the process of discovering new knowledge, proposing original interpretations of a digital trace, or determining the functionality of any technology or service. A template structure is discussed and provided in Appendix S1 which sets out a minimum standard for metadata describing any GTD's production process and content. It is suggested that such an approach can support the maintenance of trust in any GTD and improve the shareability of it.Item Open Access Investigative opportunities from smart heating technology: a preliminary evaluation(Taylor and Francis, 2024-03-27) Horsman, GraemeThis work provides a case study documenting one of the first digital forensic examinations of a smart home heat system – Hive. The case study tries to address the forensic questions that law enforcement are likely to have in regards to smart home heating systems as well as highlighting relevant digital investigative opportunities. Data extracted from the Hive smart heating app (v. 10.54.2 (3)) when used on iOS v. 14.2 is presented and evaluated in order to determine whether it is possible to understand who has control over a heating system and what their controlling actions look like in regard to operating the system. Findings show that user information, pincode details and records of how the heating and water functionality can be acquired.Item Open Access The detection problem: an eight-decade challenge: the difficulty of practically detecting and discriminating mines, booby traps, and victim operated improvised explosive devices(The Center for International Stabilization and Recovery (CISR) : James Madison University, 2024-03-27) Evans, Roly H. P.; Temple, Tracey; Nelson, LizReliably detecting and discriminating mines, booby traps, and victim operated improvised explosive devices remains a stubborn problem for both humanitarian demining organizations and the military. Since mines were widely used during the Second World War, much effort has been expended on the detection problem, with limited success. The aim of being able to positively identify a device first time remains elusive since the scientific challenge of positively identifying different substances in the ground is formidable. This article critically examines the detection problem and suggests that in the continued absence of a ‘silver bullet’ technological solution, the best means currently available to manage the risk of concealed explosive devices is the systematic collection and analysis of relevant operational data from the field.Item Open Access Know thy enemy and know yourself – the role of operational data in managing the mines and booby trap threat in vietnam, 1965–73(SAGE, 2024-03-12) Evans, Roland; Temple, Tracey; Nelson, LizVictim operated explosive devices (VOEDs) such as mines and booby traps, have been an enduring problem since their large-scale use started in the 1940s. While the overall problem is often known about in general terms, the real complexion of the problem was not necessarily fully appreciated. Eventually the need to understand the problem and the response to it was partially identified and acted upon in Vietnam through the collection and analysis of operational data. This did not solve the problem of mines and booby traps, but it did offer a means to better manage the threat.