Staff publications (CDS)

Permanent URI for this collection

https://dspace.lib.cranfield.ac.uk/handle/1826/13

Browse

Now showing 1 - 20 of 1045

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.
Open Access
Guest editorial: Climate Neutral Supply Chains
(IEEE, 2024-04-30) Mukandwal, Prabhjot; Guntuka, Laharish; Aktas, Emel
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, Mark
Satellites 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.
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, Sara
Novel 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.
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, Allie
The 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.
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, Mehmet
The 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.
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.
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, Rachael
In 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.
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, Akachai
To 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.
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, Simon
In 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.
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.
Open Access
A template for creating and sharing ground truth data in digital forensics
(Wiley, 2024-04-21) Horsman, Graeme
Ground 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.
Open Access
Investigative opportunities from smart heating technology: a preliminary evaluation
(Taylor and Francis, 2024-03-27) Horsman, Graeme
This 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.
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, Liz
Victim 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.
Open Access
Understanding agile: a case study in educational complexity
(The International Academic Forum (IAFOR), 2023-11-11) Barker, Stephen G.
As the nature of engineering concepts, products and processes becomes more intricate and detailed, so the task of understanding, managing and implementing them becomes more complex. This paper takes one such development concept, Agile, and examines how the orthogonal, multi-faceted nature of both the concept and its application makes it difficult to understand and employ and considers in this context the andragogical difficulties posed when trying to teach it to level 7 students. The practice of Agile is often considered to be either the application of methods such as Scrum, extreme programming (XP) or Scaled Agile Framework (SAFe), or the implementation of agile values or principles. In practice, however, a greater level of complexity exists and many more facets need to be considered, such as organisational structure, suitability of project and product, skill set of individuals, and even the mind set of those involved, because the adoption of agile requires more than the use of a technique as part of normal business procedures. In order to understand the complexity of a concept such as agile and the implications which it poses for andragogical teaching and learning strategies, the nature of the concept is first considered to identify the challenges that it creates for education, before a mapping of teaching strategies to agile facets is produced, and thought is given to the creation of an andragogical mechanism which will promote and engender student understanding of the concept and how it can be applied across a range of topic areas in context.
Open Access
Evaluating student perspectives on understanding of complex systems
(The International Academic Forum (IAFOR), 2022-11-15) Barker, Stephen G.
Advances in technological detail and sophistication have resulted in more complex products, systems and services which can be more difficult for individuals to conceptualise and understand. This eventuality has potential to increase risks and assumptions in the use, operation, and management over time of such products and therefore presents a growing problem for those who have to plan and undertake such activities. It can thus be seen as important that people are informed as to the possible ramifications of increased complexity, and this presents a challenge to educators in terms of how the notion of ever-increasing complexity can be taught and inculcated. Previous work has considered how this might be achieved, evaluating learner preferences, mechanisms to describe greater complexity and its effects, and teaching strategies which can facilitate that learning and understanding. This paper builds upon the earlier work in the light of having since delivered complex systems course content at masters level. By viewing the situation through the prism of student learning experience and using informal discussion with learners and formal feedback on factors such as comprehension of topic, ability to analyse and evaluate holistically, and capability to apply understanding to real-life business scenarios, this paper assesses areas that students perceived as difficult or challenging to explicate and actualise. This is then placed in the overall context of the course cohort to analyse trends and whether different students experienced problems with the same issues before suggesting a revised andragogical strategy to address issues and improve the student learning experience.
Open Access
Relating the cultural iceberg to organisations and information warfare
(International Command and Control (C2) Institute, 2021-10-28) Hilton, Jeremy
The Iceberg as initially proposed by Schein is often used when considering organizational culture and to try to understand what leads to visible behaviors and actions through surfacing the assumptions, values and beliefs that led to the selection of strategies, goals etc. When considering C2 in a contested environment, decision-making should never take place without fully understanding the context within which the decisions are being made. From all that is observable, we select those aspects that interest us and interpret them in our personal context and give them meaning accordingly. We will draw conclusions having applied our existing assumptions, frequently without acknowledging them, and develop beliefs based on these conclusions. Finally, we take actions that seem right in our context. The actions we may take will be from our personal repertoire according to the means available to us, the strength of our drive (motivation), and any constraints or restraints imposed on us. However, we need to see the ‘other’ by standing in their shoes and seek to understand their beliefs, values, motivations, and drives. We need to understand the impact of their organizational structures and technology on their courses of action. However, we also need to recognize they are doing the same to us, so we also need to look within to assess as best as possible those actions being taken against us to influence our beliefs, values, motivations, structures, and technological enablers. Finally, we explore what the impact on organization and C2 approaches and the challenges that need to be addressed. This is the critical understanding we need to achieve success.
Open Access
Analyses of the brown stain on the Parthenon Centaur head in Denmark
(Springer, 2024-01-16) Rasmussen, Kaare Lund; Rasmussen, Bodil Bundgaard; Delbey, Thomas; Bonaduce, Ilaria; Kjeldsen, Frank; Gorshkov, Vladimir
In 1688 two sculptural fragments, a head of bearded man and a head of an unbearded youth, arrived in Copenhagen, sent from Athens as a gift to King Christian 5. They were placed in the Royal Kunstkammer, their provenance given as the Temple of Artemis in Ephesos, one of the Seven Wonders of the World. Almost a hundred and fifty years later, in the early 1820’s they were noticed and studied by two scholars independently visiting the Kunstkammer. However, both concluded that the two heads belonged to one of the metopes decorating the south side of the Parthenon temple on the Acropolis in Athens, showing fighting between Greeks and the mythical Centaurs, part man and part horse. In the 1830’s another sculptural fragment, a horse’s hoof, obtained through the German archaeologist and state antiquary of Greece, Ludwig Ross, reached Copenhagen. It was forwarded by the Danish consul to Athens, C.T. Falbe, as a gift to King Christian 8. The inventory reads: ‘… was found on the Acropolis near the Parthenon temple and is supposed to belong to one the Centaurs on the metopes.’ The present paper focuses solely on the head of the Centaur. A brown stain was noticed on the Parthenon marbles as early as 1830 by the British Museum and has ever since eluded a deeper understanding of its genesis despite many investigations and attempts of analyses. A quite similar brown stain can be observed on the Centaur’s head in Copenhagen as well. The present study reports analyses by LA-ICP-MS, SEM–EDX, µXRD, GC–MS, and LC–MS-MS, as well as optical microscopy of five small samples sequestered in 1999 from the Centaur head curated by the National Museum of Denmark. Our analyses show that the brown stain consists of two consecutively added surficial layers of the calcium oxalate minerals whewellite and weddellite. Despite a thorough search using proteomics, we have found no viable organic precursor material for the oxalates. Our results do not solve the mystery of the formation of the brown stain, but they do further qualify the structure and characterization of the brown stain.
Open Access
Guidance for the identification of bony lesions related to smallpox
(Elsevier, 2023-12-30) Crawford, Rosie R.; Hodson, Claire M.; Errickson, David
Objective: This research aimed to address the underrepresentation of smallpox (osteomyelitis variolosa) in palaeopathology, providing a synthesis of published literature and presenting guidance for the identification of osteomyelitis variolosa in non-adult and adult skeletal remains. Materials and methods: Literature regarding smallpox and published reports of individuals with osteomyelitis variolosa were synthesised and critiqued to produce clear diagnostic criteria for the identification of smallpox osteologically. Results: Associated osteological changes begin in non-adults, where skeletal morphology is rapidly changing. Characteristic lesions associated with non-adult osteomyelitis variolosa include inflammation and destructive remodelling of long-bone joints and metaphyses. Where childhood infection was survived, residual osteomyelitis variolosa lesions should also be visible in adults in the osteoarchaeological record. Conclusions: Despite long-term clinical recognition, only limited osteological and archaeological evidence of osteomyelitis variolosa has yet emerged. With improved diagnostic criteria, osteomyelitis variolosa may be more frequently identified. Significance: This is the first synthesis of osteomyelitis variolosa encompassing both clinical and palaeopathological literature, providing detailed guidance for the identification of osteomyelitis variolosa in skeletal remains. It will lead to the increased identification of smallpox osteologically. Limitations: Differential diagnoses should always be considered. The archaeological longevity of smallpox, and the potential for archaeological VARV to cause clinically recognised smallpox, is currently unknown. Characteristic bone changes in the archaeological record may be other, extinct human-infecting-orthopoxviruses. Suggestions for further research: Further consideration of the implications of age of smallpox contraction on bony pathology: whether epiphyses are affected differently due to state of fusion. Reassessment of individuals previously identified with smallpox-consistent lesions, but otherwise diagnosed.
Open Access
A low-cost miniature immunosensor for haemoglobin as a device for the future detection of gastrointestinal bleeding
(Royal Society of Chemistry, 2024-01-11) Demirhan, Alper; Chianella, Iva; Patil, Samadhan B.; Khalid, Ata
Gastrointestinal bleeding (GIB) is a serious medical condition, which requires immediate attention to establish the cause of the bleeding. Here, we present the development of a miniaturised electrochemical impedance spectroscopy (EIS) device for the detection of GIB. The device performs EIS measurements up to 100 kHz. Following the development of an immunosensor for haemoglobin (Hb) on screen printed electrodes, the EIS device was used for detecting Hb as an early indication of bleeding. The sensor was able to detect Hb in a redox solution in a linear range between 5 μg mL−1 and 60 μg mL−1, with a limit of detection of 13.3 μg mL−1. It was also possible to detect Hb in simulated intestinal fluid, without the need for a redox solution, within a range of 10 μg mL−1 to 10 mg mL−1 with a limit of detection of 2.31 mg mL−1. The miniature EIS device developed in this work is inexpensive, with an estimated cost per unit of £30, and has shown a comparable performance to existing commercial tools, demonstrating its potential to be used in the future as an ingestible sensor to detect GIB. All these measurements were carried out in a purpose built flow cell with supporting hardware electronics outside the cell. Integration of the hardware and the sensing electrodes was demonstrated in pill form. This pill after integration sampling fluidics has potential to be used in detecting gastrointestinal bleeding.